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Sample records for absolute extreme ultraviolet

  1. Absolute sensitivity calibration of extreme ultraviolet photoresists

    SciTech Connect

    Jones, Juanita; Naulleau, Patrick P.; Gullikson, Eric M.; Aquila, Andrew; George, Simi; Niakoula, Dimitra

    2008-05-16

    One of the major challenges facing the commercialization of extreme ultraviolet (EUV) lithography remains simultaneously achieving resist sensitivity, line-edge roughness, and resolution requirement. Sensitivity is of particular concern owing to its direct impact on source power requirements. Most current EUV exposure tools have been calibrated against a resist standard with the actual calibration of the standard resist dating back to EUV exposures at Sandia National Laboratories in the mid 1990s. Here they report on an independent sensitivity calibration of two baseline resists from the SEMATECH Berkeley MET tool performed at the Advanced Light Source Calibrations and Standards beamline. The results show the baseline resists to be approximately 1.9 times faster than previously thought based on calibration against the long standing resist standard.

  2. Absolute sensitivity calibration of extreme ultraviolet photoresists.

    PubMed

    Naulleau, Patrick P; Gullikson, Eric M; Aquila, Andrew; George, Simi; Niakoula, Dimitra

    2008-07-21

    One of the major challenges facing the commercialization of extreme ultraviolet (EUV) lithography remains simultaneously achieving resist sensitivity, line-edge roughness, and resolution requirement. Sensitivity is of particular concern owing to its direct impact on source power requirements. Most current EUV exposure tools have been calibrated against a resist standard with the actual calibration of the standard resist dating back to EUV exposures at Sandia National Laboratories in the mid 1990s. Here we report on an independent sensitivity calibration of two baseline resists from the SEMATECH Berkeley MET tool performed at the Advanced Light Source Calibrations and Standards beamline. The results show the baseline resists to be approximately 1.9 times faster than previously thought based on calibration against the long standing resist standard.

  3. Absolute, Extreme-Ultraviolet, Solar Spectral Irradiance Monitor (AESSIM)

    NASA Technical Reports Server (NTRS)

    Huber, Martin C. E.; Smith, Peter L.; Parkinson, W. H.; Kuehne, M.; Kock, M.

    1988-01-01

    AESSIM, the Absolute, Extreme-Ultraviolet, Solar Spectral Irradiance Monitor, is designed to measure the absolute solar spectral irradiance at extreme-ultraviolet (EUV) wavelengths. The data are required for studies of the processes that occur in the earth's upper atmosphere and for predictions of atmospheric drag on space vehicles. AESSIM is comprised of sun-pointed spectrometers and newly-developed, secondary standards of spectral irradiance for the EUV. Use of the in-orbit standard sources will eliminate the uncertainties caused by changes in spectrometer efficiency that have plagued all previous measurements of the solar spectral EUV flux.

  4. Upgrade of absolute extreme ultraviolet diagnostic on J-TEXT.

    PubMed

    Zhang, X L; Cheng, Z F; Hou, S Y; Zhuang, G; Luo, J

    2014-11-01

    The absolute extreme ultraviolet (AXUV) diagnostic system is used for radiation observation on J-TEXT tokamak [J. Zhang, G. Zhuang, Z. J. Wang, Y. H. Ding, X. Q. Zhang, and Y. J. Tang, Rev. Sci. Instrum. 81, 073509 (2010)]. The upgrade of the AXUV system is aimed to improve the spatial resolution and provide a three-dimensional image on J-TEXT. The new system consists of 12 AXUV arrays (4 AXUV16ELG arrays, 8 AXUV20ELG arrays). The spatial resolution in the cross-section is 21 mm for the AXUV16ELG arrays and 17 mm for the AXUV20ELG arrays. The pre-amplifier is also upgraded for a higher signal to noise ratio. By upgrading the AXUV imaging system, a more accurate observation on the radiation information is obtained.

  5. Upgrade of absolute extreme ultraviolet diagnostic on J-TEXT

    SciTech Connect

    Zhang, X. L.; Cheng, Z. F. Hou, S. Y.; Zhuang, G.; Luo, J.

    2014-11-15

    The absolute extreme ultraviolet (AXUV) diagnostic system is used for radiation observation on J-TEXT tokamak [J. Zhang, G. Zhuang, Z. J. Wang, Y. H. Ding, X. Q. Zhang, and Y. J. Tang, Rev. Sci. Instrum. 81, 073509 (2010)]. The upgrade of the AXUV system is aimed to improve the spatial resolution and provide a three-dimensional image on J-TEXT. The new system consists of 12 AXUV arrays (4 AXUV16ELG arrays, 8 AXUV20ELG arrays). The spatial resolution in the cross-section is 21 mm for the AXUV16ELG arrays and 17 mm for the AXUV20ELG arrays. The pre-amplifier is also upgraded for a higher signal to noise ratio. By upgrading the AXUV imaging system, a more accurate observation on the radiation information is obtained.

  6. Absolute measurement of undulator radiation in the extreme ultraviolet

    NASA Astrophysics Data System (ADS)

    Maezawa, H.; Mitani, S.; Suzuki, Y.; Kanamori, H.; Tamamushi, S.; Mikuni, A.; Kitamura, H.; Sasaki, T.

    1983-04-01

    The spectral brightness of undulator radiation emitted by the model PMU-1 incorporated in the SOR-RING, the dedicated synchrotron radiation source in Tokyo, has been studied in the extreme ultraviolet region from 21.6 to 72.9 eV as a function of the electron energy γ, the field parameter K, and the angle of observation ϴ in the absolute scale. A series of measurements covering the first and the second harmonic component of undulator radiation was compared with the fundamental formula λ n= {λ 0}/{2nγ 2}( {1+K 2}/{2}+γϴ 2 and the effects of finite emittance were studied. The brightness at the first peak was smaller than the theoretical value, while an enhanced second harmonic component was observed.

  7. Upgrade of absolute extreme ultraviolet diagnostic on J-TEXTa)

    NASA Astrophysics Data System (ADS)

    Zhang, X. L.; Cheng, Z. F.; Hou, S. Y.; Zhuang, G.; Luo, J.

    2014-11-01

    The absolute extreme ultraviolet (AXUV) diagnostic system is used for radiation observation on J-TEXT tokamak [J. Zhang, G. Zhuang, Z. J. Wang, Y. H. Ding, X. Q. Zhang, and Y. J. Tang, Rev. Sci. Instrum. 81, 073509 (2010)]. The upgrade of the AXUV system is aimed to improve the spatial resolution and provide a three-dimensional image on J-TEXT. The new system consists of 12 AXUV arrays (4 AXUV16ELG arrays, 8 AXUV20ELG arrays). The spatial resolution in the cross-section is 21 mm for the AXUV16ELG arrays and 17 mm for the AXUV20ELG arrays. The pre-amplifier is also upgraded for a higher signal to noise ratio. By upgrading the AXUV imaging system, a more accurate observation on the radiation information is obtained.

  8. Absolute sensitivity calibration of an extreme ultraviolet spectrometer for tokamak measurements

    NASA Astrophysics Data System (ADS)

    Guirlet, R.; Schwob, J. L.; Meyer, O.; Vartanian, S.

    2017-01-01

    An extreme ultraviolet spectrometer installed on the Tore Supra tokamak has been calibrated in absolute units of brightness in the range 10-340 Å. This has been performed by means of a combination of techniques. The range 10-113 Å was absolutely calibrated by using an ultrasoft-X ray source emitting six spectral lines in this range. The calibration transfer to the range 113-182 Å was performed using the spectral line intensity branching ratio method. The range 182-340 Å was calibrated thanks to radiative-collisional modelling of spectral line intensity ratios. The maximum sensitivity of the spectrometer was found to lie around 100 Å. Around this wavelength, the sensitivity is fairly flat in a 80 Å wide interval. The spatial variations of sensitivity along the detector assembly were also measured. The observed trend is related to the quantum efficiency decrease as the angle of the incoming photon trajectories becomes more grazing.

  9. Absolute intensity calibration of the Wendelstein 7-X high efficiency extreme ultraviolet overview spectrometer system

    NASA Astrophysics Data System (ADS)

    Greiche, Albert; Biel, Wolfgang; Marchuk, Oleksandr; Burhenn, Rainer

    2008-09-01

    The new high effiency extreme ultraviolet overview spectrometer (HEXOS) system for the stellarator Wendelstein 7-X is now mounted for testing and adjustment at the tokamak experiment for technology oriented research (TEXTOR). One part of the testing phase was the intensity calibration of the two double spectrometers which in total cover a spectral range from 2.5 to 160.0 nm with overlap. This work presents the current intensity calibration curves for HEXOS and describes the method of calibration. The calibration was implemented with calibrated lines of a hollow cathode light source and the branching ratio technique. The hollow cathode light source provides calibrated lines from 16 up to 147 nm. We could extend the calibrated region in the spectrometers down to 2.8 nm by using the branching line pairs emitted by an uncalibrated pinch extreme ultraviolet light source as well as emission lines from boron and carbon in TEXTOR plasmas. In total HEXOS is calibrated from 2.8 up to 147 nm, which covers most of the observable wavelength region. The approximate density of carbon in the range of the minor radius from 18 to 35 cm in a TEXTOR plasma determined by simulating calibrated vacuum ultraviolet emission lines with a transport code was 5.5×1017 m-3 which corresponds to a local carbon concentration of 2%.

  10. A new absolute extreme ultraviolet image system designed for studying the radiated power of the Joint Texas Experimental Tokamak discharges

    SciTech Connect

    Zhang, J.; Zhuang, G.; Wang, Z. J.; Ding, Y. H.; Zhang, X. Q.; Tang, Y. J.

    2010-07-15

    A bolometer imaging system mounted on different toroidal and poloidal locations used for radiation observation has been developed in the Joint Texas Experimental Tokamak (J-TEXT tokamak). Three miniature pinhole AXUV16ELG (16 elements absolute extreme ultraviolet silicon photodiodes) array cameras, which are settled down in the same toroidal position but in three different poloidal places, can provide a broad viewing angle that covers the whole plasma cross-section, and hence can measure the total radiated power and provide the radiated emissive profile, while nine AXUV10EL (10 elements absolute extreme ultraviolet silicon photodiodes) array cameras are divided into three groups and will be mounted on different toroidal locations to observe the toroidal radiated power distribution. Among these detectors, one element of the AXUV16ELG array is absolutely calibrated by the synchrotron radiation source to verify the system reliability. Although there are some discrepancies between the typical responsivity given by IRD Co. and the calibrated results, it is confirmed that the discrepancies have no major effect on the final result after the simulation. The details of the system as well as observations are presented in the paper.

  11. A new absolute extreme ultraviolet image system designed for studying the radiated power of the Joint Texas Experimental Tokamak discharges.

    PubMed

    Zhang, J; Zhuang, G; Wang, Z J; Ding, Y H; Zhang, X Q; Tang, Y J

    2010-07-01

    A bolometer imaging system mounted on different toroidal and poloidal locations used for radiation observation has been developed in the Joint Texas Experimental Tokamak (J-TEXT tokamak). Three miniature pinhole AXUV16ELG (16 elements absolute extreme ultraviolet silicon photodiodes) array cameras, which are settled down in the same toroidal position but in three different poloidal places, can provide a broad viewing angle that covers the whole plasma cross-section, and hence can measure the total radiated power and provide the radiated emissive profile, while nine AXUV10EL (10 elements absolute extreme ultraviolet silicon photodiodes) array cameras are divided into three groups and will be mounted on different toroidal locations to observe the toroidal radiated power distribution. Among these detectors, one element of the AXUV16ELG array is absolutely calibrated by the synchrotron radiation source to verify the system reliability. Although there are some discrepancies between the typical responsivity given by IRD Co. and the calibrated results, it is confirmed that the discrepancies have no major effect on the final result after the simulation. The details of the system as well as observations are presented in the paper.

  12. Absolute sensitivity calibration of vacuum and extreme ultraviolet spectrometer systems and Z{sub eff} measurement based on bremsstrahlung continuum in HL-2A tokamak

    SciTech Connect

    Zhou Hangyu; Cui Zhengying; Fu Bingzhong; Sun Ping; Gao Yadong; Xu Yuan; Lu Ping; Yang Qingwei; Duan Xuru; Morita, Shigeru; Goto, Motoshi; Dong Chunfeng

    2012-10-15

    A grazing-incidence flat-field extreme ultraviolet (EUV) spectrometer has been newly developed in HL-2A tokamak. Typical spectral lines are observed from intrinsic impurities of carbon, oxygen, iron, and extrinsic impurity of helium in the wavelength range of 20 A-500 A. Bremsstrahlung continuum is measured at different electron densities of HL-2A discharges to calibrate absolute sensitivity of the EUV spectrometer system and to measure effective ionic charge, Z{sub eff}. The sensitivity of a vacuum ultraviolet (VUV) spectrometer system is also absolutely calibrated in overlapped wavelength range of 300 A-500 A by comparing the intensity between VUV and EUV line emissions.

  13. Extreme ultraviolet lithography machine

    DOEpatents

    Tichenor, Daniel A.; Kubiak, Glenn D.; Haney, Steven J.; Sweeney, Donald W.

    2000-01-01

    An extreme ultraviolet lithography (EUVL) machine or system for producing integrated circuit (IC) components, such as transistors, formed on a substrate. The EUVL machine utilizes a laser plasma point source directed via an optical arrangement onto a mask or reticle which is reflected by a multiple mirror system onto the substrate or target. The EUVL machine operates in the 10-14 nm wavelength soft x-ray photon. Basically the EUV machine includes an evacuated source chamber, an evacuated main or project chamber interconnected by a transport tube arrangement, wherein a laser beam is directed into a plasma generator which produces an illumination beam which is directed by optics from the source chamber through the connecting tube, into the projection chamber, and onto the reticle or mask, from which a patterned beam is reflected by optics in a projection optics (PO) box mounted in the main or projection chamber onto the substrate. In one embodiment of a EUVL machine, nine optical components are utilized, with four of the optical components located in the PO box. The main or projection chamber includes vibration isolators for the PO box and a vibration isolator mounting for the substrate, with the main or projection chamber being mounted on a support structure and being isolated.

  14. Method for extreme ultraviolet lithography

    DOEpatents

    Felter, T. E.; Kubiak, G. D.

    2000-01-01

    A method of producing a patterned array of features, in particular, gate apertures, in the size range 0.4-0.05 .mu.m using projection lithography and extreme ultraviolet (EUV) radiation. A high energy laser beam is used to vaporize a target material in order to produce a plasma which in turn, produces extreme ultraviolet radiation of a characteristic wavelength of about 13 nm for lithographic applications. The radiation is transmitted by a series of reflective mirrors to a mask which bears the pattern to be printed. The demagnified focused mask pattern is, in turn, transmitted by means of appropriate optics and in a single exposure, to a substrate coated with photoresists designed to be transparent to EUV radiation and also satisfy conventional processing methods.

  15. Method for extreme ultraviolet lithography

    DOEpatents

    Felter, T. E.; Kubiak, Glenn D.

    1999-01-01

    A method of producing a patterned array of features, in particular, gate apertures, in the size range 0.4-0.05 .mu.m using projection lithography and extreme ultraviolet (EUV) radiation. A high energy laser beam is used to vaporize a target material in order to produce a plasma which in turn, produces extreme ultraviolet radiation of a characteristic wavelength of about 13 nm for lithographic applications. The radiation is transmitted by a series of reflective mirrors to a mask which bears the pattern to be printed. The demagnified focused mask pattern is, in turn, transmitted by means of appropriate optics and in a single exposure, to a substrate coated with photoresists designed to be transparent to EUV radiation and also satisfy conventional processing methods.

  16. Research in extreme ultraviolet and far ultraviolet astronomy

    NASA Technical Reports Server (NTRS)

    Labov, S. E.

    1985-01-01

    Instruments designed to explore different aspects of far and extreme ultraviolet cosmic radiation were studied. The far ultraviolet imager (FUVI) was flown on the Aries sounding rocket. Its unique large format 75mm detector mapped out the far ultraviolet background radiation with a resolution of only a few arc minutes. Analysis of this data indicates to what extent the FUVI background is extra galactic in origin. A power spectrum of the spatial fluctuations will have direct consequences for galactic evolution.

  17. The Diffuse Extreme Ultraviolet Background

    NASA Technical Reports Server (NTRS)

    Vallerga, John; Slavin, Jonathan

    1996-01-01

    Observations of the diffuse EUV background towards 138 different directions using the spectrometers aboard the Extreme Ultraviolet Explorer satellite (EUVE) have been combined into a spectrum from 150A to 730A and represent an effective exposure of 18 million seconds. There is no significant evidence of any non-local line flux in the resultant spectrum such as that from a hot coronal plasma. These results are inconsistent with the Wisconsin C and B broad-band surveys assuming the source is a logT = 5.8 - 6.1 hot plasma in ionization equilibrium with solar abundances, confirming the previous result of Jelinksy, Vallerga and Edelstein) (hereafter Paper 1) using an observation along the ecliptic with the same instrument. To make these results consistent with the previous broad-band surveys, the plasma responsible for the emission must either be depleted in Fe by a factor of approximately 6, be behind an absorbing slab of neutral H with a column of 2 x 10(exp 19)/sq cm, or not be in collisional ionization equilibrium (CIE). One such non-CIE model (Breitswerdt and Schmutzier) that explains the soft x-ray results is also inconsistent with this EUV data.

  18. Towards High Accuracy Reflectometry for Extreme-Ultraviolet Lithography.

    PubMed

    Tarrio, Charles; Grantham, Steven; Squires, Matthew B; Vest, Robert E; Lucatorto, Thomas B

    2003-01-01

    Currently the most demanding application of extreme ultraviolet optics is connected with the development of extreme ultraviolet lithography. Not only does each of the Mo/Si multilayer extreme-ultraviolet stepper mirrors require the highest attainable reflectivity at 13 nm (nearly 70 %), but the central wavelength of the reflectivity of these mirrors must be measured with a wavelength repeatability of 0.001 nm and the peak reflectivity of the reflective masks with a repeatability of 0.12 %. We report on two upgrades of our NIST/DARPA Reflectometry Facility that have given us the ability to achieve 0.1 % repeatability and 0.3 % absolute uncertainty in our reflectivity measurements. A third upgrade, a monochromator with thermal and mechanical stability for improved wavelength repeatability, is currently in the design phase.

  19. Astronomy and the Extreme Ultraviolet Explorer satellite.

    PubMed

    Bowyer, S

    1994-01-07

    The extreme ultraviolet wave band (100 to 912 angstroms) was thought until recently to be useless to astronomy, primarily because the opacity of the interstellar medium would prevent observations at these wavelengths. However, the interstellar medium has been found to be markedly inhomogeneous in both density and ionization state and the sun is fortunately located in a region of low extreme ultraviolet opacity. The Extreme Ultraviolet Explorer, launched in June 1992, has surveyed the sky in this wave band and has detected a wide variety of astronomical sources at considerable distances, including some extragalactic objects. Studies in the extreme ultraviolet band have already begun to increase our understanding of the contents of the universe.

  20. Astronomy and the Extreme Ultraviolet Explorer satellite

    NASA Technical Reports Server (NTRS)

    Bowyer, S.

    1994-01-01

    The extreme ultraviolet wave band (100 to 912 angstroms) was thought until recently to be useless to astronomy, primarily because the opacity of the interstellar medium would prevent observations at these wavelengths. However, the interstellar medium has been found to be markedly inhomogeneous in both density and ionization state and the sun is fortunately located in a region of low extreme ultraviolet opacity. The Extreme Ultraviolet Explorer, launched in June 1992, has surveyed the sky in this wave band and has detected a wide variety of astronomical sources at considerable distances, including some extragalactic objects. Studies in the extreme ultraviolet band have already begun to increase our understanding of the contents of the universe.

  1. Extreme Ultraviolet Explorer Bright Source List

    NASA Technical Reports Server (NTRS)

    Malina, Roger F.; Marshall, Herman L.; Antia, Behram; Christian, Carol A.; Dobson, Carl A.; Finley, David S.; Fruscione, Antonella; Girouard, Forrest R.; Hawkins, Isabel; Jelinsky, Patrick

    1994-01-01

    Initial results from the analysis of the Extreme Ultraviolet Explorer (EUVE) all-sky survey (58-740 A) and deep survey (67-364 A) are presented through the EUVE Bright Source List (BSL). The BSL contains 356 confirmed extreme ultraviolet (EUV) point sources with supporting information, including positions, observed EUV count rates, and the identification of possible optical counterparts. One-hundred twenty-six sources have been detected longward of 200 A.

  2. Research in extreme ultraviolet and far ultraviolet astronomy

    NASA Technical Reports Server (NTRS)

    Bowyer, C. S.

    1985-01-01

    The Far Ultraviolet imager (FUVI) was flown on the Aries class sounding rocket 24.015, producing outstanding results. The diffuse extreme ultraviolet (EUV) background spectrometer which is under construction is described. It will be launched on the Black Brant sounding rocket flight number 27.086. Ongoing design studies of a high resolution spectrometer are discussed. This instrument incorporates a one meter normal incidence mirror and will be suitable for an advanced Spartan mission.

  3. Photoresist composition for extreme ultraviolet lithography

    DOEpatents

    Felter, T. E.; Kubiak, G. D.

    1999-01-01

    A method of producing a patterned array of features, in particular, gate apertures, in the size range 0.4-0.05 .mu.m using projection lithography and extreme ultraviolet (EUV) radiation. A high energy laser beam is used to vaporize a target material in order to produce a plasma which in turn, produces extreme ultraviolet radiation of a characteristic wavelength of about 13 nm for lithographic applications. The radiation is transmitted by a series of reflective mirrors to a mask which bears the pattern to be printed. The demagnified focused mask pattern is, in turn, transmitted by means of appropriate optics and in a single exposure, to a substrate coated with photoresists designed to be transparent to EUV radiation and also satisfy conventional processing methods. A photoresist composition for extreme ultraviolet radiation of boron carbide polymers, hydrochlorocarbons and mixtures thereof.

  4. Photoresist composition for extreme ultraviolet lithography

    SciTech Connect

    Felter, T.E.; Kubiak, G.D.

    1999-11-23

    A method of producing a patterned array of features, in particular, gate apertures, in the size range 0.4--0.05 {mu}m using projection lithography and extreme ultraviolet (EUV) radiation is disclosed. A high energy laser beam is used to vaporize a target material in order to produce a plasma which in turn, produces extreme ultraviolet radiation of a characteristic wavelength of about 13 nm for lithographic applications. The radiation is transmitted by a series of reflective mirrors to a mask which bears the pattern to be printed. The demagnified focused mask pattern is, in turn, transmitted by means of appropriate optics and in a single exposure, to a substrate coated with photoresists designed to be transparent to EUV radiation and also satisfy conventional processing methods. A photoresist composition for extreme ultraviolet radiation of boron carbide polymers, hydrochlorocarbons and mixtures thereof.

  5. Absolute photon-flux measurements in the vacuum ultraviolet

    NASA Technical Reports Server (NTRS)

    Samson, J. A. R.; Haddad, G. N.

    1974-01-01

    Absolute photon-flux measurements in the vacuum ultraviolet have extended to short wavelengths by use of rare-gas ionization chambers. The technique involves the measurement of the ion current as a function of the gas pressure in the ion chamber. The true value of the ion current, and hence the absolute photon flux, is obtained by extrapolating the ion current to zero gas pressure. Examples are given at 162 and 266 A. The short-wavelength limit is determined only by the sensitivity of the current-measuring apparatus and by present knowledge of the photoionization processes that occur in the rate gases.

  6. Far and extreme ultraviolet astronomy with ORFEUS

    NASA Technical Reports Server (NTRS)

    Kraemer, G.; Barnstedt, J.; Eberhard, N.; Grewing, M.; Gringel, W.; Haas, C.; Kaelble, A.; Kappelmann, N.; Petrik, J.; Appenzeller, I.

    1990-01-01

    ORFEUS (Orbiting and Retrievable Far and Extreme Ultraviolet Spectrometer) is a 1 m normal incidence telescope for spectroscopic investigations of cosmic sources in the far and extreme ultraviolet spectral range. The instrument will be integrated into the freeflyer platform ASTRO-SPAS. ORFEUS-SPAS is scheduled with STS ENDEAVOUR in September 1992. We describe the telescope with its two spectrometer and their capabilities i.e., spectral range, resolution and overall sensitivity. The main classes of objects to be observed with the instrument are discussed and two examples of simulated spectra for the white dwarf HZ43 and an O9-star in LMC are shown.

  7. Defect-tolerant extreme ultraviolet nanoscale printing.

    PubMed

    Urbanski, L; Isoyan, A; Stein, A; Rocca, J J; Menoni, C S; Marconi, M C

    2012-09-01

    We present a defect-free lithography method for printing periodic features with nanoscale resolution using coherent extreme ultraviolet light. This technique is based on the self-imaging effect known as the Talbot effect, which is produced when coherent light is diffracted by a periodic mask. We present a numerical simulation and an experimental verification of the method with a compact extreme ultraviolet laser. Furthermore, we explore the extent of defect tolerance by testing masks with different defect layouts. The experimental results are in good agreement with theoretical calculations.

  8. Thin film filter lifetesting results in the extreme ultraviolet

    NASA Technical Reports Server (NTRS)

    Vedder, P. W.; Vallerga, J. V.; Gibson, J. L.; Stock, J.; Siegmund, O. H. W.

    1993-01-01

    We present the results of the thin film filter lifetesting program conducted as part of the NASA Extreme Ultraviolet Explorer (EUVE) satellite mission. This lifetesting program is designed to monitor changes in the transmission and mechanical properties of the EUVE filters over the lifetime of the mission (fabrication, assembly, launch and operation). Witness test filters were fabricated from thin film foils identical to those used in the flight filters. The witness filters have been examined and calibrated periodically over the past seven years. The filters have been examined for evidence of pinholing, mechanical degradation, and oxidation. Absolute transmissions of the flight and witness filters have been measured in the extreme ultraviolet (EUV) over six orders of magnitude at numerous wavelengths using the Berkeley EUV Calibration Facility.

  9. Absolute calibration of vacuum ultraviolet spectrograph system for plasma diagnostics

    SciTech Connect

    Yoshikawa, M.; Kubota, Y.; Kobayashi, T.; Saito, M.; Numada, N.; Nakashima, Y.; Cho, T.; Koguchi, H.; Yagi, Y.; Yamaguchi, N.

    2004-10-01

    A space- and time-resolving vacuum ultraviolet (VUV) spectrograph system has been applied to diagnose impurity ions behavior in plasmas produced in the tandem mirror GAMMA 10 and the reversed field pinch TPE-RX. We have carried out ray tracing calculations for obtaining the characteristics of the VUV spectrograph and calibration experiments to measure the absolute sensitivities of the VUV spectrograph system for the wavelength range from 100 to 1100 A. By changing the incident angle, 50.6 deg. -51.4 deg., to the spectrograph whose nominal incident angle is 51 deg., we can change the observing spectral range of the VUV spectrograph. In this article, we show the ray tracing calculation results and absolute sensitivities when the angle of incidence into the VUV spectrograph is changed, and the results of VUV spectroscopic measurement in both GAMMA 10 and TPE-RX plasmas.

  10. THE ABSOLUTE MAGNITUDES OF TYPE Ia SUPERNOVAE IN THE ULTRAVIOLET

    SciTech Connect

    Brown, Peter J.; Roming, Peter W. A.; Ciardullo, Robin; Gronwall, Caryl; Hoversten, Erik A.; Pritchard, Tyler; Milne, Peter; Bufano, Filomena; Mazzali, Paolo; Elias-Rosa, Nancy; Filippenko, Alexei V.; Li Weidong; Foley, Ryan J.; Hicken, Malcolm; Kirshner, Robert P.; Gehrels, Neil; Holland, Stephen T.; Immler, Stefan; Phillips, Mark M.; Still, Martin

    2010-10-01

    We examine the absolute magnitudes and light-curve shapes of 14 nearby (redshift z = 0.004-0.027) Type Ia supernovae (SNe Ia) observed in the ultraviolet (UV) with the Swift Ultraviolet/Optical Telescope. Colors and absolute magnitudes are calculated using both a standard Milky Way extinction law and one for the Large Magellanic Cloud that has been modified by circumstellar scattering. We find very different behavior in the near-UV filters (uvw1{sub rc} covering {approx}2600-3300 A after removing optical light, and u {approx} 3000-4000 A) compared to a mid-UV filter (uvm2 {approx}2000-2400 A). The uvw1{sub rc} - b colors show a scatter of {approx}0.3 mag while uvm2-b scatters by nearly 0.9 mag. Similarly, while the scatter in colors between neighboring filters is small in the optical and somewhat larger in the near-UV, the large scatter in the uvm2 - uvw1 colors implies significantly larger spectral variability below 2600 A. We find that in the near-UV the absolute magnitudes at peak brightness of normal SNe Ia in our sample are correlated with the optical decay rate with a scatter of 0.4 mag, comparable to that found for the optical in our sample. However, in the mid-UV the scatter is larger, {approx}1 mag, possibly indicating differences in metallicity. We find no strong correlation between either the UV light-curve shapes or the UV colors and the UV absolute magnitudes. With larger samples, the UV luminosity might be useful as an additional constraint to help determine distance, extinction, and metallicity in order to improve the utility of SNe Ia as standardized candles.

  11. The Stellar Extreme-Ultraviolet Radiation Field

    NASA Astrophysics Data System (ADS)

    Vallerga, John

    1998-04-01

    The local extreme ultraviolet (EUV) radiation field from stellar sources has been determined by combining the EUV spectra of 54 stars, taken with the spectrometers aboard the Extreme Ultraviolet Explorer satellite. The resultant spectrum over the range 70-730 Å is estimated to be 95% complete above 400 Å and 90% complete above 200 Å. The flux contributed by two B stars and three hot white dwarfs dominate the spectrum except at the shortest wavelengths, where an assortment of EUV source types contribute. The high electron densities measured toward nearby stars can be accounted for by photoionization from this radiation field, but the spectrum is too soft to explain the overionization of helium with respect to hydrogen recently measure in the Local Cloud.

  12. Extreme Ultraviolet Explorer Science Operation Center

    NASA Technical Reports Server (NTRS)

    Wong, G. S.; Kronberg, F. A.; Meriwether, H. D.; Wong, L. S.; Grassi, C. L.

    1993-01-01

    The EUVE Science Operations Center (ESOC) is a satellite payload operations center for the Extreme Ultraviolet Explorer project, located on the Berkeley campus of the University of California. The ESOC has the primary responsibility for commanding the EUVE telescopes and monitoring their telemetry. The ESOC is one of a very few university-based satellite operations facilities operating with NASA. This article describes the history, operation, and advantages of the ESOC as an on-campus operations center.

  13. Ultraviolet photometry from the Orbiting Astronomical Observatory. XXI - Absolute energy distribution of stars in the ultraviolet

    NASA Technical Reports Server (NTRS)

    Bless, R. C.; Code, A. D.; Fairchild, E. T.

    1976-01-01

    The absolute energy distribution in the ultraviolet is given for the stars alpha Vir, eta UMa, and alpha Leo. The calibration is based on absolute heterochromatic photometry between 2920 and 1370 A carried out with an Aerobee sounding rocket. The fundamental radiation standard is the synchrotron radiation from 240-MeV electrons in a certain synchrotron storage ring. On the basis of the sounding-rocket calibration, the preliminary OAO-2 spectrometer calibration has been revised; the fluxes for the three program stars are tabulated in energy per second per square centimeter per unit wavelength interval.

  14. Sensitivity calibration of an imaging extreme ultraviolet spectrometer-detector system for determining the efficiency of broadband extreme ultraviolet sources

    NASA Astrophysics Data System (ADS)

    Fuchs, S.; Rödel, C.; Krebs, M.; Hädrich, S.; Bierbach, J.; Paz, A. E.; Kuschel, S.; Wünsche, M.; Hilbert, V.; Zastrau, U.; Förster, E.; Limpert, J.; Paulus, G. G.

    2013-02-01

    We report on the absolute sensitivity calibration of an extreme ultraviolet (XUV) spectrometer system that is frequently employed to study emission from short-pulse laser experiments. The XUV spectrometer, consisting of a toroidal mirror and a transmission grating, was characterized at a synchrotron source in respect of the ratio of the detected to the incident photon flux at photon energies ranging from 15.5 eV to 99 eV. The absolute calibration allows the determination of the XUV photon number emitted by laser-based XUV sources, e.g., high-harmonic generation from plasma surfaces or in gaseous media. We have demonstrated high-harmonic generation in gases and plasma surfaces providing 2.3 μW and μJ per harmonic using the respective generation mechanisms.

  15. Extreme ultraviolet photoionization of aldoses and ketoses

    NASA Astrophysics Data System (ADS)

    Shin, Joong-Won; Dong, Feng; Grisham, Michael E.; Rocca, Jorge J.; Bernstein, Elliot R.

    2011-04-01

    Gas phase monosaccharides (2-deoxyribose, ribose, arabinose, xylose, lyxose, glucose galactose, fructose, and tagatose), generated by laser desorption of solid sample pellets, are ionized with extreme ultraviolet photons (EUV, 46.9 nm, 26.44 eV). The resulting fragment ions are analyzed using a time of flight mass spectrometer. All aldoses yield identical fragment ions regardless of size, and ketoses, while also generating same ions as aldoses, yields additional features. Extensive fragmentation of the monosaccharides is the result the EUV photons ionizing various inner valence orbitals. The observed fragmentation patterns are not dependent upon hydrogen bonding structure or OH group orientation.

  16. Extreme Ultraviolet Explorer (EUVE): Emergency support

    NASA Technical Reports Server (NTRS)

    Zayas, H.; Barrowman, J.

    1991-01-01

    The Extreme Ultraviolet Explorer (EUVE) will conduct a survey of the entire celestial sphere in the extreme ultraviolet (UV) spectrum, 100 to 1000 angstrom units. This survey will be accomplished using four grazing incidence telescopes mounted on a spinning spacecraft whose spin axis is along the Sun line. Data is taken only when the spacecraft is in the Earth's shadow. The EUVE will be placed in a near circular orbit by a Delta expendable launch vehicle. The design orbit is circular at an altitude of 550 km by 28.5 degrees for a period of 96 minutes. The EUVE will be flown on a standardized Explorer Platform (EP) which will be reused for followup Explorer missions. Coverage will be provided by the Deep Space Network (DSN) for EUVE emergencies that would prevent communications via the normal channels of the Tracking and Data Relay Satellite System (TDRSS). Emergency support will be provided by the 26-meter subnet. Data is presented in tabular form for DSN support, frequency assignments, telemetry, and command.

  17. Extreme Ultraviolet Solar Spectroscopy with CHIPS

    NASA Astrophysics Data System (ADS)

    Hurwitz, Mark V.; Sasseen, T. P.; Sirk, M.; Marchant, W.; McDonald, J.; Thorsness, J.; Lewis, M.; Woods, T.

    2006-12-01

    The Cosmic Hot Interstellar Plasma Spectrometer (CHIPS) can be utilized to collect extreme ultraviolet spectra of the full solar disk. CHIPS has been collecting solar spectra since late 2005, although the observation geometry was not standardized until April 2006. Since that time, CHIPS has been accumulating spectra on nearly a daily basis. As for the diffuse emission that CHIPS was designed to observe, the bandpass is about 90 to 260 Å, with a peak resolution (λ/Δλ) of about 100. The instrumental efficiency as a function of wavelength is expected to be stable, but is subject to an overall scale factor that is less certain. We explain how CHIPS can collect these spectra, and present representative results.

  18. Femtosecond transparency in the extreme ultraviolet

    NASA Astrophysics Data System (ADS)

    Tarana, Michal; Greene, Chris H.

    2012-06-01

    Electromagnetically induced transparency-like behavior in the extreme ultraviolet (XUV) is studied theoretically, including the effect of intense 800nm laser dressing of He 2s2p(^1P^o) and 2p^2(^2S^e) autoionizing states. We present an ab initio solution of the time-dependent Schr"odinger equation in an LS-coupling configuration interaction basis set. The method enables a rigorous treatment of optical field ionization of these coupled autoionizing states into the N = 2 continuum in addition to N = 1. Our calculated transient absorption spectra show the formation of the Autler-Townes doublet in the presence of the dressing laser field. The presented results are in encouraging agreement with experiment [1]. [4pt] [1] Z.H. Loh, C.H. Greene, and S. R. Leone, Chem. Phys. 350, 7 (2008)

  19. Extreme ultraviolet spectral irradiance measurements since 1946

    NASA Astrophysics Data System (ADS)

    Schmidtke, G.

    2015-03-01

    In the physics of the upper atmosphere the solar extreme ultraviolet (EUV) radiation plays a dominant role controlling most of the thermospheric/ionospheric (T/I) processes. Since this part of the solar spectrum is absorbed in the thermosphere, platforms to measure the EUV fluxes became only available with the development of rockets reaching altitude levels exceeding 80 km. With the availability of V2 rockets used in space research, recording of EUV spectra started in 1946 using photographic films. The development of pointing devices to accurately orient the spectrographs toward the sun initiated intense activities in solar-terrestrial research. The application of photoelectric recording technology enabled the scientists placing EUV spectrometers aboard satellites observing qualitatively strong variability of the solar EUV irradiance on short-, medium-, and long-term scales. However, as more measurements were performed more radiometric EUV data diverged due to the inherent degradation of the EUV instruments with time. Also, continuous recording of the EUV energy input to the T/I system was not achieved. It is only at the end of the last century that there was progress made in solving the serious problem of degradation enabling to monitore solar EUV fluxes with sufficient radiometric accuracy. The data sets available allow composing the data available to the first set of EUV data covering a period of 11 years for the first time. Based on the sophisticated instrumentation verified in space, future EUV measurements of the solar spectral irradiance (SSI) are promising accuracy levels of about 5% and less. With added low-cost equipment, real-time measurements will allow providing data needed in ionospheric modeling, e.g., for correcting propagation delays of navigation signals from space to earth. Adding EUV airglow and auroral emission monitoring by airglow cameras, the impact of space weather on the terrestrial T/I system can be studied with a spectral terrestrial

  20. Absolute fluxes of six hot stars in the ultraviolet (912-1600 Angstroms)

    SciTech Connect

    Woods, T.N.

    1985-01-01

    Six hot stars were observed on 1984 March 2 from a Black Brant V sounding rocket (NASA 21.085UG). The absolute fluxes from ..gamma../sup 2/ Vel, zeta Pup, ..cap alpha.. CMa, ..gamma.. Ori, ..beta.. Tau, and epsilon Per were measured in the spectral region between 912 and 1600 A at 10 A resolution. Comparisons with revised Voyager 1 and Voyager 2 Ultraviolet Spectrometer data (Holberg 1984) and previous sounding rocket data (Brune et al. 1979) are evaluated. In general, the two sounding rocket experiments are in good agreement, and the revised Voyager data and the sounding rocket data are in agreement except at wavelengths below 1000 A. Comparisons with stellar models (Kurucz 1979) are presented showing discrepancies near 1200 A and below 1000 A. Determination of interstellar absorption using the data on these stars proved to be unsatisfactory due partly to the inaccuracies of the stellar models; however, a list of hot stars suitable for deriving the interstellar extinction is included to aid future extreme ultraviolet experiments, such as the Hopkins Ultraviolet Telescope (HUT).

  1. Reflective masks for extreme ultraviolet lithography

    SciTech Connect

    Nguyen, Khanh Bao

    1994-05-01

    Extreme ultraviolet lithographic masks are made by patterning multilayer reflective coatings with high normal incidence reflectivity. Masks can be patterned by depositing a patterned absorber layer above the coating or by etching the pattern directly into the coating itself. Electromagnetic simulations showed that absorber-overlayer masks have superior imaging characteristics over etched masks (less sensitive to incident angles and pattern profiles). In an EUVL absorber overlayer mask, defects can occur in the mask substrate, reflective coating, and absorber pattern. Electromagnetic simulations showed that substrate defects cause the most severe image degradation. A printability study of substrate defects for absorber overlayer masks showed that printability of 25 nm high substrate defects are comparable to defects in optical lithography. Simulations also indicated that the manner in which the defects are covered by multilayer reflective coatings can affect printability. Coverage profiles that result in large lateral spreading of defect geometries amplify the printability of the defects by increasing their effective sizes. Coverage profiles of Mo/Si coatings deposited above defects were studied by atomic force microscopy and TEM. Results showed that lateral spread of defect geometry is proportional to height. Undercut at defect also increases the lateral spread. Reductions in defect heights were observed for 0.15 μm wide defect lines. A long-term study of Mo/Si coating reflectivity revealed that Mo/Si coatings with Mo as the top layer suffer significant reductions in reflectivity over time due to oxidation.

  2. Coherence techniques at extreme ultraviolet wavelengths

    SciTech Connect

    Chang, Chang

    2002-01-01

    The renaissance of Extreme Ultraviolet (EUV) and soft x-ray (SXR) optics in recent years is mainly driven by the desire of printing and observing ever smaller features, as in lithography and microscopy. This attribute is complemented by the unique opportunity for element specific identification presented by the large number of atomic resonances, essentially for all materials in this range of photon energies. Together, these have driven the need for new short-wavelength radiation sources (e.g. third generation synchrotron radiation facilities), and novel optical components, that in turn permit new research in areas that have not yet been fully explored. This dissertation is directed towards advancing this new field by contributing to the characterization of spatial coherence properties of undulator radiation and, for the first time, introducing Fourier optical elements to this short-wavelength spectral region. The first experiment in this dissertation uses the Thompson-Wolf two-pinhole method to characterize the spatial coherence properties of the undulator radiation at Beamline 12 of the Advanced Light Source. High spatial coherence EUV radiation is demonstrated with appropriate spatial filtering. The effects of small vertical source size and beamline apertures are observed. The difference in the measured horizontal and vertical coherence profile evokes further theoretical studies on coherence propagation of an EUV undulator beamline. A numerical simulation based on the Huygens-Fresnel principle is performed.

  3. The Extreme Ultraviolet Variability of Quasars

    NASA Astrophysics Data System (ADS)

    Punsly, Brian; Marziani, Paola; Zhang, Shaohua; Muzahid, Sowgat; O'Dea, Christopher P.

    2016-10-01

    We study the extreme ultraviolet (EUV) variability (rest frame wavelengths 500-920 Å) of high-luminosity quasars using Hubble Space Telescope (HST) (low to intermediate redshift sample) and Sloan Digital sky Survey (SDSS) (high redshift sample) archives. The combined HST and SDSS data indicates a much more pronounced variability when the sampling time between observations in the quasar rest frame is \\gt 2× {10}7 {{s}} compared to \\lt 1.5× {10}7 s. Based on an excess variance analysis, for time intervals \\lt 2× {10}7 {{s}} in the quasar rest frame, 10% of the quasars (4/40) show evidence of EUV variability. Similarly, for time intervals \\gt 2× {10}7 {{s}} in the quasar rest frame, 55% of the quasars (21/38) show evidence of EUV variability. The propensity for variability does not show any statistically significant change between 2.5× {10}7 {{s}} and 3.16× {10}7 {{s}} (1 year). The temporal behavior is one of a threshold time interval for significant variability as opposed to a gradual increase on these timescales. A threshold timescale can indicate a characteristic spatial dimension of the EUV region. We explore this concept in the context of the slim disk models of accretion. We find that for rapidly spinning black holes, the radial infall time to the plunge region of the optically thin surface layer of the slim disk that is responsible for the preponderance of the EUV flux emission (primarily within 0-7 black hole radii from the inner edge of the disk) is consistent with the empirically determined variability timescale.

  4. Spectral observations of the extreme ultraviolet background.

    PubMed

    Labov, S E; Bowyer, S

    1991-04-20

    A grazing incidence spectrometer was designed to measure the diffuse extreme ultraviolet background. It was flown on a sounding rocket, and data were obtained on the diffuse background between 80 and 650 angstroms. These are the first spectral measurements of this background below 520 angstroms. Several emission features were detected, including interplanetary He I 584 angstroms emission and geocoronal He II 304 angstroms emission. Other features observed may originate in a hot ionized interstellar gas, but if this interpretation is correct, gas at several different temperatures is present. The strongest of these features is consistent with O V emission at 630 angstroms. This emission, when combined with upper limits for other lines, restricts the temperature of this component to 5.5 < log T < 5.7, in agreement with temperatures derived from O VI absorption studies. A power-law distribution of temperatures is consistent with this feature only if the power-law coefficient is negative, as is predicted for saturated evaporation of clouds in a hot medium. In this case, the O VI absorption data confine the filling factor of the emission of f < or = 4% and the pressure to more than 3.7 x 10(4) cm-3 K, substantially above ambient interstellar pressure. Such a pressure enhancement has been predicted for clouds undergoing saturated evaporation. Alternatively, if the O V emission covers a considerable fraction of the sky, it would be a major source of ionization. A feature centered at about 99 angstroms is well fitted by a cluster of Fe XVIII and Fe XIX lines from gas at log T = 6.6-6.8. These results are consistent with previous soft X-ray observations with low-resolution detectors. A feature found near 178 angstroms is consistent with Fe X and Fe XI emission from gas at log T = 6; this result is consistent with results from experiments employing broad-band soft X-ray detectors.

  5. Absolute measurement of the extreme UV solar flux

    NASA Technical Reports Server (NTRS)

    Carlson, R. W.; Ogawa, H. S.; Judge, D. L.; Phillips, E.

    1984-01-01

    A windowless rare-gas ionization chamber has been developed to measure the absolute value of the solar extreme UV flux in the 50-575-A region. Successful results were obtained on a solar-pointing sounding rocket. The ionization chamber, operated in total absorption, is an inherently stable absolute detector of ionizing UV radiation and was designed to be independent of effects from secondary ionization and gas effusion. The net error of the measurement is + or - 7.3 percent, which is primarily due to residual outgassing in the instrument, other errors such as multiple ionization, photoelectron collection, and extrapolation to the zero atmospheric optical depth being small in comparison. For the day of the flight, Aug. 10, 1982, the solar irradiance (50-575 A), normalized to unit solar distance, was found to be 5.71 + or - 0.42 x 10 to the 10th photons per sq cm sec.

  6. [Study on the absolute spectral irradiation calibration method for far ultraviolet spectrometer in remote sensing].

    PubMed

    Yu, Lei; Lin, Guan-Yu; Chen, Bin

    2013-01-01

    The present paper studied spectral irradiation responsivities calibration method which can be applied to the far ultraviolet spectrometer for upper atmosphere remote sensing. It is difficult to realize the calibration for far ultraviolet spectrometer for many reasons. Standard instruments for far ultraviolet waveband calibration are few, the degree of the vacuum experiment system is required to be high, the stabilities of the experiment are hardly maintained, and the limitation of the far ultraviolet waveband makes traditional diffuser and the integrating sphere radiance calibration method difficult to be used. To solve these problems, a new absolute spectral irradiance calibration method was studied, which can be applied to the far ultraviolet calibration. We build a corresponding special vacuum experiment system to verify the calibration method. The light source system consists of a calibrated deuterium lamp, a vacuum ultraviolet monochromater and a collimating system. We used the calibrated detector to obtain the irradiance responsivities of it. The three instruments compose the calibration irradiance source. We used the "calibration irradiance source" to illuminate the spectrometer prototype and obtained the spectral irradiance responsivities. It realized the absolute spectral irradiance calibration for the far ultraviolet spectrometer utilizing the calibrated detector. The absolute uncertainty of the calibration is 7.7%. The method is significant for the ground irradiation calibration of the far ultraviolet spectrometer in upper atmosphere remote sensing.

  7. Measurements of electron and proton heating temperatures from extreme-ultraviolet light images at 68 eV in petawatt laser experiments

    SciTech Connect

    Gu Peimin; Zhang, B.; Key, M. H.; Hatchett, S. P.; Barbee, T.; Freeman, R. R.; Akli, K.; Hey, D.; King, J. A.; Mackinnon, A. J.; Snavely, R. A.; Stephens, R. B.

    2006-11-15

    A 68 eV extreme-ultraviolet light imaging diagnostic measures short pulse isochoric heating by electrons and protons in petawatt laser experiments. Temperatures are deduced from the absolute intensities and comparison with modeling using a radiation hydrodynamics code.

  8. Energy deposition in ultrathin extreme ultraviolet resist films: extreme ultraviolet photons and keV electrons

    NASA Astrophysics Data System (ADS)

    Kyser, David F.; Eib, Nicholas K.; Ritchie, Nicholas W. M.

    2016-07-01

    The absorbed energy density (eV/cm3) deposited by extreme ultraviolet (EUV) photons and electron beam (EB) high-keV electrons is proposed as a metric for characterizing the sensitivity of EUV resist films. Simulations of energy deposition are used to calculate the energy density as a function of the incident aerial flux (EUV: mJ/cm2, EB: μC/cm2). Monte Carlo calculations for electron exposure are utilized, and a Lambert-Beer model for EUV absorption. The ratio of electron flux to photon flux which results in equivalent energy density is calculated for a typical organic chemically amplified resist film and a typical inorganic metal-oxide film. This ratio can be used to screen EUV resist materials with EB measurements and accelerate advances in EUV resist systems.

  9. High-intensity source of extreme ultraviolet

    NASA Technical Reports Server (NTRS)

    Paresce, E.; Kumar, S.; Bowyer, S.

    1972-01-01

    High intensity ultraviolet radiation source was developed which is suitable for emission below 500 A. Source, useful for 100 to 1000 A range, is simple and inexpensive to construct, easy to operate, and very stable. Because of sufficiently intense output spectrum, source can be used with monochromator at wavelengths as low as 160 A.

  10. Extreme ultraviolet photodissociative excitation of molecular oxygen

    NASA Technical Reports Server (NTRS)

    Carlson, R. W.

    1974-01-01

    Photodissociation processes in molecular oxygen occurring in the wavelength range from 500 to 900 A, investigated through observations of the resulting atomic fluorescence radiation, are reported. The dispersed radiation from a continuous light source was used to excite the gas, and the resulting fluorescence radiation was observed in the ultraviolet and infrared. The results obtained are compared with the dissociation cross sections derived by Matsunaga and Watanabe (1967).

  11. Extreme Ultraviolet (XUV) Coronal Spectroheliograph - Experiment S082A

    NASA Technical Reports Server (NTRS)

    1973-01-01

    This chart describes Skylab's Extreme Ultraviolet (XUV) Coronal Spectroheliograph, one of the eight Apollo Telescope Mount facilities. It was designed to sequentially photograph the solar chromosphere and corona in selected ultraviolet wavelengths . The instrument also obtained information about composition, temperature, energy conversion and transfer, and plasma processes of the chromosphere and lower corona. The Marshall Space Flight Center had program management responsibility for the development of Skylab hardware and experiments.

  12. Extreme Ultraviolet (XUV) Coronal Spectroheliograph - Experiment S082A

    NASA Technical Reports Server (NTRS)

    1971-01-01

    This photograph shows Skylab's Extreme Ultraviolet (XUV) Spectroheliograph during an acceptance test and checkout procedures in April 1971. The unit was an Apollo Telescope Mount (ATM) instrument designed to sequentially photograph the solar chromosphere and corona in selected ultraviolet wavelengths. The instrument also obtained information about composition, temperature, energy conversion and transfer, and plasma processes of the chromosphere and lower corona. The Marshall Space Flight Center had program management responsibility for the development of Skylab hardware and experiments.

  13. Far-Ultraviolet Absolute Flux of α Virginis

    NASA Astrophysics Data System (ADS)

    Morales, Carmen; Trapero, Joaquín; Gómez, José F.; Giménez, Álvaro; Orozco, Verónica; Bowyer, Stuart; Edelstein, Jerry; Korpela, Eric; Lampton, Michael; Cobb, Jeff

    2000-02-01

    We present the far-ultraviolet spectrum of α Virginis taken with Espectrógrafo Ultravioleta extremo para la Radiación Difusa (EURD) spectrograph on board MINISAT-01. The spectral range covered is from ~900 to 1080 Å with 5 Å spectral resolution. We have fitted Kurucz models to IUE spectra of α Vir and compared the extension of the model to our wavelengths with EURD data. This comparison shows that EURD fluxes are consistent with the prediction of the model within ~20%-30%, depending on the reddening assumed. EURD fluxes are consistent with Voyager observations but are ~60% higher than most previous rocket observations of α Vir. Based on the development and utilization of the Espectrógrafo Ultravioleta de Radiación Difusa, a collaboration of the Spanish Instituto Nacional de Técnica Aeroespacial and the Center for EUV Astrophysics, University of California, Berkeley.

  14. 'EXTREME ULTRAVIOLET WAVES' ARE WAVES: FIRST QUADRATURE OBSERVATIONS OF AN EXTREME ULTRAVIOLET WAVE FROM STEREO

    SciTech Connect

    Patsourakos, Spiros; Vourlidas, Angelos E-mail: vourlidas@nrl.navy.mil

    2009-08-01

    The nature of coronal mass ejection (CME)-associated low corona propagating disturbances, 'extreme ultraviolet (EUV) waves', has been controversial since their discovery by EIT on SOHO. The low-cadence, single-viewpoint EUV images and the lack of simultaneous inner corona white-light observations have hindered the resolution of the debate on whether they are true waves or just projections of the expanding CME. The operation of the twin EUV imagers and inner corona coronagraphs aboard STEREO has improved the situation dramatically. During early 2009, the STEREO Ahead (STA) and Behind (STB) spacecrafts observed the Sun in quadrature having a {approx}90 deg. angular separation. An EUV wave and CME erupted from active region 11012, on February 13, when the region was exactly at the limb for STA and hence at disk center for STB. The STEREO observations capture the development of a CME and its accompanying EUV wave not only with high cadence but also in quadrature. The resulting unprecedented data set allowed us to separate the CME structures from the EUV wave signatures and to determine without doubt the true nature of the wave. It is a fast-mode MHD wave after all.

  15. Absolute, Extreme-Ultraviolet Solar Spectral Irradiance Monitor (AESSIM)

    DTIC Science & Technology

    1994-04-01

    4 SUN SUN (xO.2) Neon Argon Lexan Tin 0.5 0 Helium Krypton Aluminum Inoium C Carbon 0.5 0 E Helium Xenon Titanium Indium -0.5 0 Neon Nitric Oxide Tin...required, and some concepts for solar EUV monitoring missions. 3. ACTIVITIES 3.1 Low-Power AESSIM Calibration lamp A portable secondary ’standard’ of...the Harvard College Observatory (HCO) and then tested at PTB and HCO. We tested the lamp in laboratory optical systems that had been modified to allow

  16. Method for generating extreme ultraviolet with mather-type plasma accelerators for use in Extreme Ultraviolet Lithography

    DOEpatents

    Hassanein, Ahmed; Konkashbaev, Isak

    2006-10-03

    A device and method for generating extremely short-wave ultraviolet electromagnetic wave uses two intersecting plasma beams generated by two plasma accelerators. The intersection of the two plasma beams emits electromagnetic radiation and in particular radiation in the extreme ultraviolet wavelength. In the preferred orientation two axially aligned counter streaming plasmas collide to produce an intense source of electromagnetic radiation at the 13.5 nm wavelength. The Mather type plasma accelerators can utilize tin, or lithium covered electrodes. Tin, lithium or xenon can be used as the photon emitting gas source.

  17. Science With The Extreme Ultraviolet Spectrometer For Solar Orbiter

    NASA Astrophysics Data System (ADS)

    Young, P. R.; EUS Science Working Group

    2007-01-01

    The CCLRC Rutherford Appleton Laboratory (UK) is leading a consortium that proposes to build an ultraviolet spectrometer for Solar Orbiter provisionally called the Extreme Ultraviolet Spectrometer (EUS). The selection of wavelength bands for EUS has been re-assessed by the EUS Science Working Group in recent months and the final decision calls for three wavelength bands covering 700-800 Å, 970-1040 Å, and 1163-1265 Å. The key features of these bands are summarised here, and particular science topics that can be addressed by EUS are discussed.

  18. Boron and silicon - Filters for the extreme ultraviolet

    NASA Technical Reports Server (NTRS)

    Labov, S.; Bowyer, S.; Steele, G.

    1985-01-01

    Thin films of boron and silicon have been developed using electron beam deposition. The transmissions of these filters were measured from soft X-ray wavelengths to the far ultraviolet and at optical wavelengths. The boron filter transmission peaks near 66 A and the silicon filter peaks near 136 A as expected on theoretical grounds, but the extreme ultraviolet bandpass is narrower than expected. The peak transmission of these filters does not change with time, but the width of the silicon filter bandpass is reduced slightly as the filter ages.

  19. Absolute far-ultraviolet spectrophotometry of hot subluminous stars from Voyager

    NASA Technical Reports Server (NTRS)

    Holberg, J. B.; Ali, B.; Carone, T. E.; Polidan, R. S.

    1991-01-01

    Observations, obtained with the Voyager ultraviolet spectrometers, are presented of absolute fluxes for two well-known hot subluminous stars: BD + 28 deg 4211, an sdO, and G191 - B2B, a hot DA white dwarf. Complete absolute energy distributions for these two stars, from the Lyman limit at 912 A to 1 micron, are given. For BD + 28 deg 4211, a single power law closely represents the entire observed energy distribution. For G191 - B2B, a pure hydrogen model atmosphere provides an excellent match to the entire absolute energy distribution. Voyager absolute fluxes are discussed in relation to those reported from various sounding rocket experiments, including a recent rocket observation of BD + 28 deg 4211.

  20. EUV SpectroPhotometer (ESP) in Extreme Ultraviolet Variability Experiment (EVE): Algorithms and Calibrations

    NASA Astrophysics Data System (ADS)

    Didkovsky, L.; Judge, D.; Wieman, S.; Woods, T.; Jones, A.

    2012-01-01

    The Extreme ultraviolet SpectroPhotometer (ESP) is one of five channels of the Extreme ultraviolet Variability Experiment (EVE) onboard the NASA Solar Dynamics Observatory (SDO). The ESP channel design is based on a highly stable diffraction transmission grating and is an advanced version of the Solar Extreme ultraviolet Monitor (SEM), which has been successfully observing solar irradiance onboard the Solar and Heliospheric Observatory (SOHO) since December 1995. ESP is designed to measure solar Extreme UltraViolet (EUV) irradiance in four first-order bands of the diffraction grating centered around 19 nm, 25 nm, 30 nm, and 36 nm, and in a soft X-ray band from 0.1 to 7.0 nm in the zeroth-order of the grating. Each band’s detector system converts the photo-current into a count rate (frequency). The count rates are integrated over 0.25-second increments and transmitted to the EVE Science and Operations Center for data processing. An algorithm for converting the measured count rates into solar irradiance and the ESP calibration parameters are described. The ESP pre-flight calibration was performed at the Synchrotron Ultraviolet Radiation Facility of the National Institute of Standards and Technology. Calibration parameters were used to calculate absolute solar irradiance from the sounding-rocket flight measurements on 14 April 2008. These irradiances for the ESP bands closely match the irradiance determined for two other EUV channels flown simultaneously: EVE’s Multiple EUV Grating Spectrograph (MEGS) and SOHO’s Charge, Element and Isotope Analysis System/ Solar EUV Monitor (CELIAS/SEM).

  1. Irradiation stability of silicon photodiodes for extreme-ultraviolet radiation

    NASA Astrophysics Data System (ADS)

    Scholze, Frank; Klein, Roman; Bock, Thomas

    2003-10-01

    Photodiodes are used as easy-to-operate detectors in the extreme-ultraviolet spectral range. At the Physikalisch-Technische Bundesanstalt photodiodes are calibrated with an uncertainty of spectral responsivity of 0.3% or less. Stable photodiodes are a prerequisite for the dissemination of these high-accuracy calibrations to customers. Silicon photodiodes with different top layers were exposed to intense extreme-ultraviolet irradiation. Diodes coated with diamondlike carbon or TiSiN proved to be stable within a few percent up to a radiant exposure of 100 kJ/cm2. The changes in responsivity could be explained as being due to carbon contamination and to changes in the internal charge collection efficiency. In ultrahigh vacuum, no indication of oxidation was found.

  2. Telescience - Concepts and contributions to the Extreme Ultraviolet Explorer mission

    NASA Technical Reports Server (NTRS)

    Marchant, Will; Dobson, Carl; Chakrabarti, Supriya; Malina, Roger F.

    1987-01-01

    It is shown how the contradictory goals of low-cost and fast data turnaround characterizing the Extreme Ultraviolet Explorer (EUVE) mission can be achieved via the early use of telescience style transparent tools and simulations. The use of transparent tools reduces the parallel development of capability while ensuring that valuable prelaunch experience is not lost in the operations phase. Efforts made to upgrade the 'EUVE electronics' simulator are described.

  3. Absolute calibration of an ultraviolet spectrometer using a stabilized laser and a cryogenic cavity radiometer

    NASA Technical Reports Server (NTRS)

    Jauniskis, L.; Foukal, P.; Kochling, H.

    1992-01-01

    We carry out the calibration of an ultraviolet spectrometer by using a cryogenic electrical-substitution radiometer and intensity-stabilized laser sources. A comparison of the error budgets for the laser-based calibration described here and for a calibration using a type-FEL tungsten spectral-irradiance standard indicates that this technique could provide an improvement of a factor of about three in the uncertainty of the spectrometer calibration, resulting in an absolute accuracy (standard deviation of three) of about 1 percent at 257 nm. The technique described here might significantly improve the accuracy of calibrations on NASA ozone-monitoring and solar ultraviolet-monitoring spectrophotometers when used to complement present procedures that employ lamps and the SURF II synchrotron ultraviolet radiation facility at the National Institute of Standards and Technology.

  4. Absolute calibration of an ultraviolet spectrometer using a stabilized laser and a cryogenic cavity radiometer.

    PubMed

    Jauniskis, L; Foukal, P; Kochling, H

    1992-09-20

    We carry out the calibration of an ultraviolet spectrometer by using a cryogenic electrical-substitution radiometer and intensity-stabilized laser sources. A comparison of the error budgets for the laser-based calibration described here and for a calibration using a type-FEL tungsten spectral-irradiance standard indicates that this technique could provide an improvement of a factor of ~3 in the uncertainty of the spectrometer calibration, resulting in an absolute accuracy (standard deviation of 3) of ~1% at 257 nm. The technique described here might significantly improve the accuracy of calibrations on NASA ozone-monitoring and solar ultraviolet-monitoring spectrophotometers when used to complement present procedures that employ lamps and the SURF II synchrotron ultraviolet radiation facility at the National Institute of Standards and Technology.

  5. Ultraviolet and extreme ultraviolet spectroscopy of the solar corona at the Naval Research Laboratory.

    PubMed

    Moses, J D; Ko, Y-K; Laming, J M; Provornikova, E A; Strachan, L; Beltran, S Tun

    2015-11-01

    We review the history of ultraviolet and extreme ultraviolet spectroscopy with a specific focus on such activities at the Naval Research Laboratory and on studies of the extended solar corona and solar-wind source regions. We describe the problem of forecasting solar energetic particle events and discuss an observational technique designed to solve this problem by detecting supra-thermal seed particles as extended wings on spectral lines. Such seed particles are believed to be a necessary prerequisite for particle acceleration by heliospheric shock waves driven by a coronal mass ejection.

  6. Calibration techniques for the NASA ICON Extreme Ultraviolet Spectrograph (EUV)

    NASA Astrophysics Data System (ADS)

    Ishikawa, Yuzo; Sirk, Martin; Wishnow, Ed; Korpela, Eric; Edelstein, Jerry; Curtis, James; Gibson, Steven R.; McCauley, Jeremy; McPhate, Jason; Smith, Christopher

    2016-09-01

    The Ionospheric Connection Explorer (ICON) is a NASA Heliophysics Explorer Mission designed to study the ionosphere. ICON will examine the Earth's upper atmosphere to better understand the relationship between Earth weather and space-weather drivers. ICON will accomplish its science objectives using a suite of 4 instruments, one of which is the Extreme Ultraviolet Spectrograph (EUV). EUV will measure daytime altitude intensity profile and spatial distribution of ionized oxygen emissions (O+ at 83.4 nm and 61.7 nm) on the limb in the thermosphere (100 to 500 km tangent altitude). EUV is a single-optic imaging spectrometer that observes in the extreme ultraviolet region of the spectrum. In this paper, we describe instrumental performance calibration measurement techniques and data analysis for EUV. Various measurements including Lyman-α scattering, instrumental and component efficiency, and field-of-view alignment verification were done in custom high-vacuum ultraviolet calibration facilities. Results from the measurements and analysis will be used to understand the instrument performance during the in-flight calibration and observations after launch.

  7. Extreme Ultraviolet Explorer. Long look at the next window

    NASA Technical Reports Server (NTRS)

    Maran, Stephen P.

    1991-01-01

    The Extreme Ultraviolet Explorer (EUVE) will map the entire sky to determine the existence, direction, brightness, and temperature of thousands of objects that are sources of so-called extreme ultraviolet (EUV) radiation. The EUV spectral region is located between the x-ray and ultraviolet regions of the electromagnetic spectrum. From the sky survey by EUVE, astronomers will determine the nature of sources of EUV light in our galaxy, and infer the distribution of interstellar gas for hundreds of light years around the solar system. It is from this gas and the accompanying dust in space that new stars and solar systems are born and to which evolving and dying stars return much of their material in an endless cosmic cycle of birth, death, and rebirth. Besides surveying the sky, astronomers will make detailed studies of selected objects with EUVE to determine their physical properties and chemical compositions. Also, they will learn about the conditions that prevail and the processes at work in stars, planets, and other sources of EUV radiation, maybe even quasars. The EUVE mission and instruments are described. The objects that EUVE will likely find are described.

  8. Pseudo-absolute quantitative analysis using gas chromatography - Vacuum ultraviolet spectroscopy - A tutorial.

    PubMed

    Bai, Ling; Smuts, Jonathan; Walsh, Phillip; Qiu, Changling; McNair, Harold M; Schug, Kevin A

    2017-02-08

    The vacuum ultraviolet detector (VUV) is a new non-destructive mass sensitive detector for gas chromatography that continuously and rapidly collects full wavelength range absorption between 120 and 240 nm. In addition to conventional methods of quantification (internal and external standard), gas chromatography - vacuum ultraviolet spectroscopy has the potential for pseudo-absolute quantification of analytes based on pre-recorded cross sections (well-defined absorptivity across the 120-240 nm wavelength range recorded by the detector) without the need for traditional calibration. The pseudo-absolute method was used in this research to experimentally evaluate the sources of sample loss and gain associated with sample introduction into a typical gas chromatograph. Standard samples of benzene and natural gas were used to assess precision and accuracy for the analysis of liquid and gaseous samples, respectively, based on the amount of analyte loaded on-column. Results indicate that injection volume, split ratio, and sampling times for splitless analysis can all contribute to inaccurate, yet precise sample introduction. For instance, an autosampler can very reproducibly inject a designated volume, but there are significant systematic errors (here, a consistently larger volume than that designated) in the actual volume introduced. The pseudo-absolute quantification capability of the vacuum ultraviolet detector provides a new means for carrying out system performance checks and potentially for solving challenging quantitative analytical problems. For practical purposes, an internal standardized approach to normalize systematic errors can be used to perform quantitative analysis with the pseudo-absolute method.

  9. Condenser for ring-field deep-ultraviolet and extreme-ultraviolet lithography

    DOEpatents

    Chapman, Henry N.; Nugent, Keith A.

    2001-01-01

    A condenser for use with a ring-field deep ultraviolet or extreme ultraviolet lithography system. A condenser includes a ripple-plate mirror which is illuminated by a collimated beam at grazing incidence. The ripple plate comprises a plate mirror into which is formed a series of channels along an axis of the mirror to produce a series of concave surfaces in an undulating pattern. Light incident along the channels of the mirror is reflected onto a series of cones. The distribution of slopes on the ripple plate leads to a distribution of angles of reflection of the incident beam. This distribution has the form of an arc, with the extremes of the arc given by the greatest slope in the ripple plate. An imaging mirror focuses this distribution to a ring-field arc at the mask plane.

  10. Condenser for ring-field deep ultraviolet and extreme ultraviolet lithography

    DOEpatents

    Chapman, Henry N.; Nugent, Keith A.

    2002-01-01

    A condenser for use with a ring-field deep ultraviolet or extreme ultraviolet lithography system. A condenser includes a ripple-plate mirror which is illuminated by a collimated or converging beam at grazing incidence. The ripple plate comprises a flat or curved plate mirror into which is formed a series of channels along an axis of the mirror to produce a series of concave surfaces in an undulating pattern. Light incident along the channels of the mirror is reflected onto a series of cones. The distribution of slopes on the ripple plate leads to a distribution of angles of reflection of the incident beam. This distribution has the form of an arc, with the extremes of the arc given by the greatest slope in the ripple plate. An imaging mirror focuses this distribution to a ring-field arc at the mask plane.

  11. High numerical aperture projection system for extreme ultraviolet projection lithography

    DOEpatents

    Hudyma, Russell M.

    2000-01-01

    An optical system is described that is compatible with extreme ultraviolet radiation and comprises five reflective elements for projecting a mask image onto a substrate. The five optical elements are characterized in order from object to image as concave, convex, concave, convex, and concave mirrors. The optical system is particularly suited for ring field, step and scan lithography methods. The invention uses aspheric mirrors to minimize static distortion and balance the static distortion across the ring field width which effectively minimizes dynamic distortion. The present invention allows for higher device density because the optical system has improved resolution that results from the high numerical aperture, which is at least 0.14.

  12. Extreme ultraviolet spectrometer based on a transmission electron microscopy grid

    DOE PAGES

    Sistrunk, Emily; Gühr, Markus

    2014-12-12

    Here, we performed extreme ultraviolet spectroscopy using an 80 lines/mm transmission electron microscope mesh as the dispersive element. We also present the usefulness of this instrument for dispersing a high harmonic spectrum from the 13th to the 29th harmonic of a Ti:sapph laser, corresponding to a wavelength range from 60 to 27 nm. The resolution of the instrument is limited by the image size of the high harmonic generation region on the detector. Finally, the resolution in first order diffraction is under 2 nm over the entire spectral range with a resolving power around 30.

  13. MoRu/Be multilayers for extreme ultraviolet applications

    DOEpatents

    Bajt, Sasa C.; Wall, Mark A.

    2001-01-01

    High reflectance, low intrinsic roughness and low stress multilayer systems for extreme ultraviolet (EUV) lithography comprise amorphous layers MoRu and crystalline Be layers. Reflectance greater than 70% has been demonstrated for MoRu/Be multilayers with 50 bilayer pairs. Optical throughput of MoRu/Be multilayers can be 30-40% higher than that of Mo/Be multilayer coatings. The throughput can be improved using a diffusion barrier to make sharper interfaces. A capping layer on the top surface of the multilayer improves the long-term reflectance and EUV radiation stability of the multilayer by forming a very thin native oxide that is water resistant.

  14. In-line extreme ultraviolet polarizer with hybrid configuration.

    PubMed

    Yang, Minghong; Tong, Xinling; Sun, Yan; Jiang, Desheng; Zhou, Ciming; Zhang, Dongsheng

    2009-03-01

    A novel hybrid Au-multilayer-Au in-line extreme ultraviolet (EUV) optical polarizer is presented in this paper. Different from all-Mo/Si multilayer EUV polarizer, this polarizer is based on the concept that Au surfaces work as reflecting elements for in-line optics routine, while polarization effect is realized by polarizing multilayer. Simulation shows that the proposed polarizer with 80 degrees-70 degrees-80 degrees angle configuration has about 30% of transmission and 12 eV of bandwidth half maximum, which enables more throughput and broader bandwidth than the all-multilayer one.

  15. Self-cleaning optic for extreme ultraviolet lithography

    DOEpatents

    Klebanoff, Leonard E.; Stulen, Richard H.

    2003-12-16

    A multilayer reflective optic or mirror for lithographic applications, and particularly extreme ultraviolet (EUV) lithography, having a surface or "capping" layer which in combination with incident radiation and gaseous molecular species such as O.sub.2, H.sub.2, H.sub.2 O provides for continuous cleaning of carbon deposits from the optic surface. The metal capping layer is required to be oxidation resistant and capable of transmitting at least 90% of incident EUV radiation. Materials for the capping layer include Ru, Rh, Pd, Ir, Pt and Au and combinations thereof.

  16. Rabi oscillations in extreme ultraviolet ionization of atomic argon

    NASA Astrophysics Data System (ADS)

    Flögel, Martin; Durá, Judith; Schütte, Bernd; Ivanov, Misha; Rouzée, Arnaud; Vrakking, Marc J. J.

    2017-02-01

    We demonstrate Rabi oscillations in nonlinear ionization of argon by an intense femtosecond extreme ultraviolet (XUV) laser field produced by high-harmonic generation. We monitor the formation of A r2 + as a function of the time delay between the XUV pulse and an additional near-infrared (NIR) femtosecond laser pulse, and show that the population of an A r+* intermediate resonance exhibits strong modulations both due to an NIR laser-induced Stark shift and XUV-induced Rabi cycling between the ground state of A r+ and the A r+* excited state. Our experiment represents a direct experimental observation of a Rabi-cycling process in the XUV regime.

  17. A rocket measurement of the extreme ultraviolet dayglow

    NASA Technical Reports Server (NTRS)

    Christensen, A. B.

    1976-01-01

    Extreme ultraviolet spectra of the mid-latitude dayglow in the wavelength range of 550 to 1250A have been obtained with a rocket borne grating spectrometer at a resolution of 20A. Spectra were obtained in the altitude range of 140 to 280 km. The spectra are dominated by emissions from atomic multiplets and no molecular bands have been identified with certainty. The strongest emissions other than H Lyman-alpha are OI (989) and OII (834). Other prominent emissions include He I(584), N II(916) and N II(1085). An unexpected feature near 612A has an intensity comparable to He I(584).

  18. Characteristics of extreme ultraviolet emission from high-Z plasmas

    NASA Astrophysics Data System (ADS)

    Ohashi, H.; Higashiguchi, T.; Suzuki, Y.; Kawasaki, M.; Suzuki, C.; Tomita, K.; Nishikino, M.; Fujioka, S.; Endo, A.; Li, B.; Otsuka, T.; Dunne, P.; O'Sullivan, G.

    2016-03-01

    We demonstrate the extreme ultraviolet (EUV) and soft x-ray sources in the 2 to 7 nm spectral region related to the beyond EUV (BEUV) question at 6.x nm and the water window source based on laser-produced high-Z plasmas. Resonance emission from multiply charged ions merges to produce intense unresolved transition arrays (UTAs), extending below the carbon K edge (4.37 nm). An outline of a microscope design for single-shot live cell imaging is proposed based on high-Z plasma UTA source, coupled to multilayer mirror optics.

  19. Polarization-ratio reflectance measurements in the extreme ultraviolet.

    PubMed

    Brimhall, N; Heilmann, N; Ware, M; Peatross, J

    2009-05-01

    We demonstrate a technique for determining optical constants of materials in the extreme UV from the ratio of p-polarized to s-polarized reflectance. The measurements are based on laser-generated high-order harmonics, which have easily rotatable linear polarization but that are prone to brightness fluctuations and systematic drifts during measurement. Rather than measure the absolute reflectance, we extract the optical constants of a material from the ratio of p-polarized to s-polarized reflectance at multiple incident angles. This has the advantage of dividing out long-term fluctuations and possible systematic errors. We show that the reflectance ratio is as sensitive as the absolute reflectance to material optical properties.

  20. Extreme ultraviolet spectroscopy of PKS 2155-304.

    PubMed

    Fruscione, A; Bowyer, S; Konigl, A; Kahn, S M

    1994-02-20

    We present the extreme ultraviolet (75-110 angstroms) spectrum of the BL Lac object PKS 2155-304, the first spectrum of an extragalactic source obtained with the Extreme Ultraviolet Explorer. The spectrum shows a generally smooth continuum, which can be modeled by a single power law plus interstellar absorption, and possibly an absorption feature at approximately 80 angstroms. The best fit to the data suggests that the EUV spectrum can be interpreted as a simple extrapolation of the X-ray continuum, with an energy index alpha approximately 1.6; however, shallower or steeper power laws with indices between -0.4 and 2.7 cannot be ruled out by the existing EUV data alone. The data provide strong constraints on the interstellar neutral H and He along the line of sight. Using a column density of 1.36 x 10(20) cm-2 for the Galactic neutral hydrogen along the PKS 2155-304 line of sight, the neutral helium column density is constrained to be 9%-10% of the hydrogen amount.

  1. Mask-induced best-focus shifts in deep ultraviolet and extreme ultraviolet lithography

    NASA Astrophysics Data System (ADS)

    Erdmann, Andreas; Evanschitzky, Peter; Neumann, Jens Timo; Gräupner, Paul

    2016-04-01

    The mask plays a significant role as an active optical element in lithography, for both deep ultraviolet (DUV) and extreme ultraviolet (EUV) lithography. Mask-induced and feature-dependent shifts of the best-focus position and other aberration-like effects were reported both for DUV immersion and for EUV lithography. We employ rigorous computation of light diffraction from lithographic masks in combination with aerial image simulation to study the root causes of these effects and their dependencies from mask and optical system parameters. Special emphasis is put on the comparison of transmission masks for DUV lithography and reflective masks for EUV lithography, respectively. Several strategies to compensate the mask-induced phase effects are discussed.

  2. High intensity vacuum ultraviolet and extreme ultraviolet production by noncollinear mixing in laser vaporized media

    NASA Astrophysics Data System (ADS)

    Todt, Michael A.; Albert, Daniel R.; Davis, H. Floyd

    2016-06-01

    A method is described for generating intense pulsed vacuum ultraviolet (VUV) and extreme ultraviolet (XUV) laser radiation by resonance enhanced four-wave mixing of commercial pulsed nanosecond lasers in laser vaporized mercury under windowless conditions. By employing noncollinear mixing of the input beams, the need of dispersive elements such as gratings for separating the VUV/XUV from the residual UV and visible beams is eliminated. A number of schemes are described, facilitating access to the 9.9-14.6 eV range. A simple and convenient scheme for generating wavelengths of 125 nm, 112 nm, and 104 nm (10 eV, 11 eV, and 12 eV) using two dye lasers without the need for dye changes is described.

  3. High intensity vacuum ultraviolet and extreme ultraviolet production by noncollinear mixing in laser vaporized media.

    PubMed

    Todt, Michael A; Albert, Daniel R; Davis, H Floyd

    2016-06-01

    A method is described for generating intense pulsed vacuum ultraviolet (VUV) and extreme ultraviolet (XUV) laser radiation by resonance enhanced four-wave mixing of commercial pulsed nanosecond lasers in laser vaporized mercury under windowless conditions. By employing noncollinear mixing of the input beams, the need of dispersive elements such as gratings for separating the VUV/XUV from the residual UV and visible beams is eliminated. A number of schemes are described, facilitating access to the 9.9-14.6 eV range. A simple and convenient scheme for generating wavelengths of 125 nm, 112 nm, and 104 nm (10 eV, 11 eV, and 12 eV) using two dye lasers without the need for dye changes is described.

  4. Toward defect-free fabrication of extreme ultraviolet photomasks

    NASA Astrophysics Data System (ADS)

    Qi, Zhengqing John; Rankin, Jed H.; Lawliss, Mark; Badger, Karen D.; Turley, Christina

    2016-04-01

    Defect-free fabrication of extreme ultraviolet (EUV) masks relies on the appropriate detection of native defects and subsequent strategies for their elimination. Commercial unavailability of actinic mask-blank inspection systems motivates the identification of an optical inspection methodology most suitable for finding relevant EUV blank defects. Studies showed that 193-nm wavelength inspection found the greatest number of printable defects as compared with rival higher-wavelength systems, establishing deep ultraviolet inspections as the blank defectivity baseline for subsequent mitigation strategies. Next, defect avoidance via pattern shifting was explored using representative 7-nm node metal/contact layer designs and 193-nm mask-blank inspection results. It was found that a significant percentage of native defects could be avoided only when the design was limited to active patterns (i.e., layouts without dummy fill). Total pattern-defect overlap remained ≤5 when metal layer blanks were chosen from the top 35% least defective substrates, while the majority of blanks remained suitable for contacts layers due to a lower active pattern density. Finally, nanomachining was used to address remaining native/multilayer defects. Native catastrophic defects were shown to recover 40% to 70% of target critical dimension after nanomachining, demonstrating the enormous potential for compensating multilayer defects.

  5. Extreme- and far-ultraviolet environment at shuttle altitudes

    SciTech Connect

    Chakrabarti, S.

    1987-01-01

    The astronomical data obtained by the Far Ultraviolet Space Telescope (FAUST) and the Very Wide Field Camera (VWFC) on board the Spacelab I mission have triggered questions on the natural and induced Extreme and Far Ultraviolet (EUV and FUV) environment of the space shuttle. Moreover, the recent discovery of approx. lk Rayleighs N/sub 2/ Lyman Birge Hopfield (LBH) nightglow emissions by the U.S. Air Force's S3-4 satellite, and subsequent confirmation by the Imaging Spectrometric Observatory (ISO) experiment on the Spacelab I mission have serious implications for the astronomical observations from the shuttle. Since both ISO and S3-4 experiments were conducted from shuttle altitudes, the implied EUV and FUV environment for astronomical observations can be severe. In order to address the question of the suitability of the shuttle as an astronomical platform, data from FAUST and other experiments were examined. It is concluded that the FAUST background is most likely due to the observation of tropical UV arcs, a natural airglow phenomenon. Strategies for future shuttle experiments to overcome this and other natural emissions are discussed.

  6. The Extreme-ultraviolet Emission from Sun-grazing Comets

    NASA Technical Reports Server (NTRS)

    Bryans, Paul; Pesnell, William D.

    2012-01-01

    The Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory has observed two Sun-grazing comets as they passed through the solar atmosphere. Both passages resulted in a measurable enhancement of extreme-ultraviolet (EUV) radiance in several of the AIA bandpasses.We explain this EUV emission by considering the evolution of the cometary atmosphere as it interacts with the ambient solar atmosphere. Molecules in the comet rapidly sublimate as it approaches the Sun. They are then photodissociated by the solar radiation field to create atomic species. Subsequent ionization of these atoms produces a higher abundance of ions than normally present in the corona and results in EUV emission in the wavelength ranges of the AIA telescope passbands.

  7. Ultrafast Extreme Ultraviolet Absorption Spectroscopy of Methylammonium Lead Iodide Perovskite

    NASA Astrophysics Data System (ADS)

    Verkamp, Max A.; Lin, Ming-Fu; Ryland, Elizabeth S.; Vura-Weis, Josh

    2016-06-01

    Methylammonium lead iodide (perovskite) is a leading candidate for use in next-generation solar cell devices. However, the photophysics responsible for its strong photovoltaic qualities are not fully understood. Ultrafast extreme ultraviolet (XUV) absorption was used to investigate electron and hole dynamics in perovskite by observing transitions from a common inner-shell level (I 4d) to the valence and conduction bands. Ultrashort (30 fs) pulses of XUV radiation with a broad spectrum (40-70 eV) were generated via high-harmonic generation using a tabletop instrument. Transient absorption measurements with visible pump and XUV probe directly observed the relaxation of charge carriers in perovskite after above-band excitation in the femtosecond and picosecond time ranges.

  8. Plans for the extreme ultraviolet explorer data base

    NASA Technical Reports Server (NTRS)

    Marshall, Herman L.; Dobson, Carl A.; Malina, Roger F.; Bowyer, Stuart

    1988-01-01

    The paper presents an approach for storage and fast access to data that will be obtained by the Extreme Ultraviolet Explorer (EUVE), a satellite payload scheduled for launch in 1991. The EUVE telescopes will be operated remotely from the EUVE Science Operation Center (SOC) located at the University of California, Berkeley. The EUVE science payload consists of three scanning telescope carrying out an all-sky survey in the 80-800 A spectral region and a Deep Survey/Spectrometer telescope performing a deep survey in the 80-250 A spectral region. Guest Observers will remotely access the EUVE spectrometer database at the SOC. The EUVE database will consist of about 2 X 10 to the 10th bytes of information in a very compact form, very similar to the raw telemetry data. A history file will be built concurrently giving telescope parameters, command history, attitude summaries, engineering summaries, anomalous events, and ephemeris summaries.

  9. Method for the protection of extreme ultraviolet lithography optics

    DOEpatents

    Grunow, Philip A.; Clift, Wayne M.; Klebanoff, Leonard E.

    2010-06-22

    A coating for the protection of optical surfaces exposed to a high energy erosive plasma. A gas that can be decomposed by the high energy plasma, such as the xenon plasma used for extreme ultraviolet lithography (EUVL), is injected into the EUVL machine. The decomposition products coat the optical surfaces with a protective coating maintained at less than about 100 .ANG. thick by periodic injections of the gas. Gases that can be used include hydrocarbon gases, particularly methane, PH.sub.3 and H.sub.2S. The use of PH.sub.3 and H.sub.2S is particularly advantageous since films of the plasma-induced decomposition products S and P cannot grow to greater than 10 .ANG. thick in a vacuum atmosphere such as found in an EUVL machine.

  10. Ultrafast Extreme Ultraviolet Induced Isomerization of Acetylene Cations

    SciTech Connect

    Jiang, Y. H.; Kurka, M.; Kuehnel, K. U.; Schroeter, C. D.; Moshammer, R.; Rudenko, A.; Foucar, L.; Herrwerth, O.; Lezius, M.; Kling, M. F.; Tilborg, J. van; Belkacem, A.; Ueda, K.; Duesterer, S.; Treusch, R.; Ullrich, J.

    2010-12-31

    Ultrafast isomerization of acetylene cations ([HC=CH]{sup +}) in the low-lying excited A{sup 2}{Sigma}{sub g}{sup +} state, populated by the absorption of extreme ultraviolet (XUV) photons (38 eV), has been observed at the Free Electron Laser in Hamburg, (FLASH). Recording coincident fragments C{sup +}+CH{sub 2}{sup +} as a function of time between XUV-pump and -probe pulses, generated by a split-mirror device, we find an isomerization time of 52{+-}15 fs in a kinetic energy release (KER) window of 5.8

  11. Nanolithography using Bessel Beams of Extreme Ultraviolet Wavelength

    NASA Astrophysics Data System (ADS)

    Fan, Daniel; Wang, Li; Ekinci, Yasin

    2016-08-01

    Bessel beams are nondiffracting light beams with large depth-of-focus and self-healing properties, making them suitable as a serial beam writing tool over surfaces with arbitrary topography. This property breaks the inherent resolution vs. depth-of-focus tradeoff of photolithography. One approach for their formation is to use circularly symmetric diffraction gratings. Such a ring grating was designed and fabricated for the extreme ultraviolet (EUV) wavelength of 13.5 nm, a candidate wavelength for future industrial lithography. Exposure of the aerial images showed that a Bessel beam with an approximately 1 mm long z-invariant central core of 223 nm diameter had been achieved, in good agreement with theory. Arbitrary patterns were written using the Bessel spot, demonstrating possible future application of Bessel beams for serial beam writing. Lithographic marks of ~30 nm size were also observed using a high resolution Bessel beam.

  12. A Penning discharge source for extreme ultraviolet calibration

    NASA Technical Reports Server (NTRS)

    Finley, David S.; Jelinsky, Patrick; Bowyer, Stuart; Malina, Roger F.

    1986-01-01

    A Penning discharge lamp for use in the calibration of instruments and components for the extreme ultraviolet has been developed. This source is sufficiently light and compact to make it suitable for mounting on the movable slit assembly of a grazing incidence Rowland circle monochromator. Because this is a continuous discharge source, it is suitable for use with photon counting detectors. Line radiation is provided both by the gas and by atoms sputtered off the interchangeable metal cathodes. Usable lines are produced by species as highly ionized as Ne IV and Al V. The wavelength coverage provided is such that a good density of emission lines is available down to wavelengths as short as 100A. This source fills the gap between 100 and 300A, which is inadequately covered by the other available compact continuous radiation sources.

  13. Extreme ultraviolet mask substrate surface roughness effects on lithography patterning

    SciTech Connect

    George, Simi; Naulleau, Patrick; Salmassi, Farhad; Mochi, Iacopo; Gullikson, Eric; Goldberg, Kenneth; Anderson, Erik

    2010-06-21

    In extreme ultraviolet lithography exposure systems, mask substrate roughness induced scatter contributes to LER at the image plane. In this paper, the impact of mask substrate roughness on image plane speckle is explicitly evaluated. A programmed roughness mask was used to study the correlation between mask roughness metrics and wafer plane aerial image inspection. We find that the roughness measurements by top surface topography profile do not provide complete information on the scatter related speckle that leads to LER at the image plane. We suggest at wavelength characterization by imaging and/or scatter measurements into different frequencies as an alternative for a more comprehensive metrology of the mask substrate/multilayer roughness effects.

  14. Source development for extreme ultraviolet lithography and water window imaging

    NASA Astrophysics Data System (ADS)

    O'Sullivan, G.; Dunne, P.; Kilbane, D.; Liu, L.; Lokasani, R.; Long, E.; Li, B. W.; McCormack, T.; O'Reilly, F.; Shiel, J.; Sokell, E.; Suzuki, C.; Wu, T.; Higashiguchi, T.

    2017-03-01

    Sources based on laser produced plasmas of tin (Sn) are currently being developed for extreme ultraviolet lithography for semiconductor fabrication. Since they operate at short wavelength (13.5 nm) they are capable of producing features with critical dimensions in the 10 nm range. Already next generation lithography sources operating at an even lower wavelength of around 6.7-6.8 nm have been proposed and research is ongoing on their feasibility for both large scale manufacturing and `at wavelength' metrology. The high resolution afforded by such short wavelengths is also of use for applications such as surface patterning and microscopy and the results of recent experiments to identify sources for operation in the `water window' (2.34-4.2 nm), where carbon absorbs strongly but water does not are summarized.

  15. Extreme ultraviolet spectra of highly ionized oxygen and fluorine

    NASA Technical Reports Server (NTRS)

    Pegg, D. J.; Griffin, P. M.; Haselton, H. H.; Laubert, R.; Mowat, J. R.; Thoe, R. S.; Peterson, R. S.; Sellin, I. A.

    1974-01-01

    The foil-excitation method has been used to study the extreme ultraviolet spectra of highly ionized oxygen and fluorine. Several previously unreported lines in heliumlike fluorine are reported and other newly reported lines in heliumlike oxygen have been measured to higher accuracy. Included in the measurements are certain heliumlike oxygen transitions of significance in interpretation of solar-flare spectral observations. The wavelength determinations are usually in good agreement with calculated results which includes relativistic corrections, but discrepancies arise when nonrelativistic calculations are used. A comparison of the present results and those recently obtained by theta-pinch and laser-induced plasma sources is made for both heliumlike and lithiumlike ions; a few discrepancies occur, with results in most cases in better agreement with relativistically corrected calculations. Certain unidentified lines in the spectra may be attributable to radiative transitions between quartet states of lithiumlike ions.

  16. Nanolithography using Bessel Beams of Extreme Ultraviolet Wavelength

    PubMed Central

    Fan, Daniel; Wang, Li; Ekinci, Yasin

    2016-01-01

    Bessel beams are nondiffracting light beams with large depth-of-focus and self-healing properties, making them suitable as a serial beam writing tool over surfaces with arbitrary topography. This property breaks the inherent resolution vs. depth-of-focus tradeoff of photolithography. One approach for their formation is to use circularly symmetric diffraction gratings. Such a ring grating was designed and fabricated for the extreme ultraviolet (EUV) wavelength of 13.5 nm, a candidate wavelength for future industrial lithography. Exposure of the aerial images showed that a Bessel beam with an approximately 1 mm long z-invariant central core of 223 nm diameter had been achieved, in good agreement with theory. Arbitrary patterns were written using the Bessel spot, demonstrating possible future application of Bessel beams for serial beam writing. Lithographic marks of ~30 nm size were also observed using a high resolution Bessel beam. PMID:27501749

  17. Normal incidence multilayer mirrors for extreme ultraviolet astronomy

    NASA Technical Reports Server (NTRS)

    Stern, R. A.; Haisch, B. M.; Joki, E. G.; Catura, R. C.

    1984-01-01

    Sputtered multilayer coatings allow the use of normal incidence optics in the extreme ultraviolet (EUV) region below 500 A. Multilayer mirrors can be tailored to provide images at strong EUV lines in the sun and stars, in many cases making more efficient use of the telescope aperture than grazing incidence optics. Alternatively, the bandpass can be broadened at the expense of peak effective area, by varying the multilayer structure over the mirror surface. Such mirrors can also serve as optical elements in spectrographs for investigation of specific emission and absorption line complexes, and are self-filtering in that they reject nearby geocoronal and cosmic resonance line backgrounds. Current efforts at the Lockheed Palo Alto Research Laboratory in the design, fabrication, and testing of EUV multilayer mirrors are discussed. This program includes the design and fabrication of normal incidence EUV multilayer mirrors, and the deposition of multilayers on lacquer-coated substrates.

  18. Ultrafast Extreme Ultraviolet Induced Isomerization of Acetylene Cations

    SciTech Connect

    Jiang, Y.; Rudenko, Artem; Herrwerth, O.; Foucar, L.; Kurka, M.; Kuhnel, K.; Lezius, M.; Kling, Matthias; van Tilborg, Jeroen; Belkacem, Ali; Ueda, K.; Dusterer, S.; Treusch, R.; Schroter, Claus-Dieter; Moshammer, Robbert; Ullrich, Joachim

    2011-06-17

    Ultrafast isomerization of acetylene cations ([HC = CH]{sup +}) in the low-lying excited A{sup 2}{Sigma}{sub g}{sup +} state, populated by the absorption of extreme ultraviolet (XUV) photons (38 eV), has been observed at the Free Electron Laser in Hamburg, (FLASH). Recording coincident fragments C{sup +} + CH{sub 2}{sup +} as a function of time between XUV-pump and -probe pulses, generated by a split-mirror device, we find an isomerization time of 52 {+-} 15 fs in a kinetic energy release (KER) window of 5.8 < KER < 8 eV, providing clear evidence for the existence of a fast, nonradiative decay channel.

  19. Direct spectrotemporal characterization of femtosecond extreme-ultraviolet pulses

    NASA Astrophysics Data System (ADS)

    Gauthier, David; Mahieu, Benoît; De Ninno, Giovanni

    2013-09-01

    We propose a method for straightforward characterization of the temporal shape of femtosecond pulses in the extreme-ultraviolet and soft x-ray spectral region. The approach is based on the presence of a significant linear frequency chirp in the pulse. This allows us to establish an homothetic relation between the pulse spectrum and its temporal profile. The theoretical approach is reminiscent of the one employed by Fraunhofer for describing far-field diffraction. As an application, we consider the case of a seeded free-electron laser (FEL). The theory is successfully benchmarked with numerical simulations and with experimental data collected on the FERMI@Elettra FEL. The proposed method provides FEL users with an online, shot-to-shot spectrotemporal diagnostic for time-resolved experiments.

  20. X Ray, Far, and Extreme Ultraviolet Coatings for Space Applications

    NASA Technical Reports Server (NTRS)

    Zukic, M.; Torr, D. G.

    1993-01-01

    The idea of utilizing imaging mirrors as narrow band filters constitutes the basis of the design of extreme ultraviolet imagers operating at 58.4 nm and 83.4 nm. The net throughput of both imaging-filtering systems is better than 20 percent. The superiority of the EUV self-filtering camera/telescope becomes apparent when compared to previously theoretically designed 83.4-nm filtering-imaging systems, which yielded transmissions of less than a few percent and therefore less than 0.1 percent throughput when combined with at least two imaging mirrors. Utilizing the self-filtering approach, instruments with similar performances are possible for imaging at other EUV wavelengths, such as 30.4 nm. The self-filtering concept is extended to the X-ray region where its application can result in the new generation of X-ray telescopes, which could replace current designs based on large and heavy collimators.

  1. Four-wave mixing experiments with extreme ultraviolet transient gratings

    NASA Astrophysics Data System (ADS)

    Bencivenga, F.; Cucini, R.; Capotondi, F.; Battistoni, A.; Mincigrucci, R.; Giangrisostomi, E.; Gessini, A.; Manfredda, M.; Nikolov, I. P.; Pedersoli, E.; Principi, E.; Svetina, C.; Parisse, P.; Casolari, F.; Danailov, M. B.; Kiskinova, M.; Masciovecchio, C.

    2015-04-01

    Four-wave mixing (FWM) processes, based on third-order nonlinear light-matter interactions, can combine ultrafast time resolution with energy and wavevector selectivity, and enable the exploration of dynamics inaccessible by linear methods. The coherent and multi-wave nature of the FWM approach has been crucial in the development of advanced technologies, such as silicon photonics, subwavelength imaging and quantum communications. All these technologies operate at optical wavelengths, which limits the spatial resolution and does not allow the probing of excitations with energy in the electronvolt range. Extension to shorter wavelengths--that is, the extreme ultraviolet and soft-X-ray ranges--would allow the spatial resolution to be improved and the excitation energy range to be expanded, as well as enabling elemental selectivity to be achieved by exploiting core resonances. So far, FWM applications at such wavelengths have been prevented by the absence of coherent sources of sufficient brightness and of suitable experimental set-ups. Here we show how transient gratings, generated by the interference of coherent extreme-ultraviolet pulses delivered by the FERMI free-electron laser, can be used to stimulate FWM processes at suboptical wavelengths. Furthermore, we have demonstrated the possibility of observing the time evolution of the FWM signal, which shows the dynamics of coherent excitations as molecular vibrations. This result opens the way to FWM with nanometre spatial resolution and elemental selectivity, which, for example, would enable the investigation of charge-transfer dynamics. The theoretical possibility of realizing these applications has already stimulated ongoing developments of free-electron lasers: our results show that FWM at suboptical wavelengths is feasible, and we hope that they will enable advances in present and future photon sources.

  2. Four-wave mixing experiments with extreme ultraviolet transient gratings.

    PubMed

    Bencivenga, F; Cucini, R; Capotondi, F; Battistoni, A; Mincigrucci, R; Giangrisostomi, E; Gessini, A; Manfredda, M; Nikolov, I P; Pedersoli, E; Principi, E; Svetina, C; Parisse, P; Casolari, F; Danailov, M B; Kiskinova, M; Masciovecchio, C

    2015-04-09

    Four-wave mixing (FWM) processes, based on third-order nonlinear light-matter interactions, can combine ultrafast time resolution with energy and wavevector selectivity, and enable the exploration of dynamics inaccessible by linear methods. The coherent and multi-wave nature of the FWM approach has been crucial in the development of advanced technologies, such as silicon photonics, subwavelength imaging and quantum communications. All these technologies operate at optical wavelengths, which limits the spatial resolution and does not allow the probing of excitations with energy in the electronvolt range. Extension to shorter wavelengths--that is, the extreme ultraviolet and soft-X-ray ranges--would allow the spatial resolution to be improved and the excitation energy range to be expanded, as well as enabling elemental selectivity to be achieved by exploiting core resonances. So far, FWM applications at such wavelengths have been prevented by the absence of coherent sources of sufficient brightness and of suitable experimental set-ups. Here we show how transient gratings, generated by the interference of coherent extreme-ultraviolet pulses delivered by the FERMI free-electron laser, can be used to stimulate FWM processes at suboptical wavelengths. Furthermore, we have demonstrated the possibility of observing the time evolution of the FWM signal, which shows the dynamics of coherent excitations as molecular vibrations. This result opens the way to FWM with nanometre spatial resolution and elemental selectivity, which, for example, would enable the investigation of charge-transfer dynamics. The theoretical possibility of realizing these applications has already stimulated ongoing developments of free-electron lasers: our results show that FWM at suboptical wavelengths is feasible, and we hope that they will enable advances in present and future photon sources.

  3. Electron-Impact-Induced Emission Cross Sections of Neon in the Extreme Ultraviolet

    NASA Technical Reports Server (NTRS)

    Kanik, I.; Ajello, J. M.; James, G. K.

    1996-01-01

    We have measured the extreme ultraviolet (EUV) spectrum of neon produced by electron excitation. The measurements were obtained under optically thin conditions, and at a spectral resolution of 0.5 nm full width at half maximum (FWHM). The most prominent features of the EUV spectrum between 45-80 nm are the resonance lines of Ne I at 73.6 and 74.4 nm and a multiplet of Ne II at 46.14 nm (the average value for the line center of the two closely spaced ion lines at 46.07 and 46.22 nm). Absolute emission cross sections of these lines at 300 eV were measured and compared to other previous measurements.

  4. Design of an extreme ultraviolet spectrometer suite to characterize rapidly heated solid matter

    NASA Astrophysics Data System (ADS)

    Ivancic, S. T.; Stillman, C. R.; Nelson, D.; Begishev, I. A.; Mileham, C.; Nilson, P. M.; Froula, D. H.

    2016-11-01

    An ultrafast streaked extreme-ultraviolet (XUV) spectrometer (5-20 nm) was developed to measure the temperature dynamics in rapidly heated samples. Rapid heating makes it possible to create exotic states of matter that can be probed during their inertial confinement time—tens of picoseconds in the case of micron-sized targets. In contrast to other forms of pyrometry, where the temperature is inferred from bulk x-ray emission, XUV emission is restricted to the sample surface, allowing for a temperature measurement at the material-vacuum interface. The surface-temperature measurement constrains models for the release of high-energy-density material. Coupling the XUV spectrometer to an ultrafast (<2-ps) streak camera provided picosecond-time scale evolution of the surface-layer emission. Two high-throughput XUV spectrometers were designed to simultaneously measure the time-resolved and absolute XUV emission.

  5. Design of an extreme ultraviolet spectrometer suite to characterize rapidly heated solid matter.

    PubMed

    Ivancic, S T; Stillman, C R; Nelson, D; Begishev, I A; Mileham, C; Nilson, P M; Froula, D H

    2016-11-01

    An ultrafast streaked extreme-ultraviolet (XUV) spectrometer (5-20 nm) was developed to measure the temperature dynamics in rapidly heated samples. Rapid heating makes it possible to create exotic states of matter that can be probed during their inertial confinement time-tens of picoseconds in the case of micron-sized targets. In contrast to other forms of pyrometry, where the temperature is inferred from bulk x-ray emission, XUV emission is restricted to the sample surface, allowing for a temperature measurement at the material-vacuum interface. The surface-temperature measurement constrains models for the release of high-energy-density material. Coupling the XUV spectrometer to an ultrafast (<2-ps) streak camera provided picosecond-time scale evolution of the surface-layer emission. Two high-throughput XUV spectrometers were designed to simultaneously measure the time-resolved and absolute XUV emission.

  6. A comparison between measured surface microtopography and observed scattering in the extreme ultraviolet

    NASA Technical Reports Server (NTRS)

    Green, James; Jelinsky, Sharon; Bowyer, Stuart; Malina, Roger F.

    1988-01-01

    The paper presents comparative measurements of surface roughness on prepared samples. These measurements have been made with both Talystep profilometers and WYKO interferometers. In addition, the scattering distribution from these samples was measured at extreme ultraviolet wavelengths. The utility of the WYKO interferometer and Talystep device for specifying extreme ultraviolet mirror surface quality is discussed.

  7. Compact extreme ultraviolet reflectometer for the characterization of grazing incidence optics based on a gas discharge light source

    SciTech Connect

    Bergmann, Klaus; Rosier, Oliver; Metzmacher, Christof

    2005-04-01

    A grazing incidence reflectometer operating in the extreme ultraviolet (EUV) spectral range around 13.5 nm is presented which is making use of a compact xenon pinch plasma light source. The apparatus allows for measuring the absolute reflectivity of a sample for grazing incidence angle in the range from typically 5 deg. to 35 deg. by comparing the EUV diode signal for the reflected light and a reference diode with an accuracy of better than 2%. Design criteria for proper matching of diode apertures and distances with respect to the spatially extended plasma source are presented. The absolute accuracy has been checked by investigating a ruthenium sample with low roughness, which has a reflectivity in the EUV close to the theoretical limit. Comparison to measurements at the EUV-reflectometer of the Physikalisch Technische Bundesanstalt in Berlin at a synchrotron source confirm the absolute accuracy of better than 2% for the reflectivity for the angle interval of interest.

  8. Extreme ultraviolet lithography mask etch study and overview

    NASA Astrophysics Data System (ADS)

    Wu, Banqiu; Kumar, Ajay; Chandrachood, Madhavi; Sabharwal, Amitabh

    2013-04-01

    An overview of extreme ultraviolet lithography (EUVL) mask etch is presented and a EUVL mask etch study was carried out. Today, EUVL implementation has three critical challenges that hinder its adoption: extreme ultraviolet (EUV) source power, resist resolution-line width roughness-sensitivity, and a qualified EUVL mask. The EUVL mask defect challenges result from defects generated during blank preparation, absorber and multilayer deposition processes, as well as patterning, etching and wet clean processes. Stringent control on several performance criteria including critical dimension (CD) uniformity, etch bias, micro-loading, profile control, defect control, and high etch selectivity requirement to capping layer is required during the resist pattern duplication on the underlying absorber layer. EUVL mask absorbers comprise of mainly tantalum-based materials rather than chrome- or MoSi-based materials used in standard optical masks. Compared to the conventional chrome-based absorbers and phase shift materials, tantalum-based absorbers need high ion energy to obtain moderate etch rates. However, high ion energy may lower resist selectivity, and could introduce defects. Current EUVL mask consists of an anti-reflective layer on top of the bulk absorber. Recent studies indicate that a native oxide layer would suffice as an anti-reflective coating layer during the electron beam inspection. The absorber thickness and the material properties are optimized based on optical density targets for the mask as well as electromagnetic field effects and optics requirements of the patterning tools. EUVL mask etch processes are modified according to the structure of the absorber, its material, and thickness. However, etch product volatility is the fundamental requirement. Overlapping lithographic exposure near chip border may require etching through the multilayer, resulting in challenges in profile control and etch selectivity. Optical proximity correction is applied to further

  9. Changes of solar extreme ultraviolet spectrum in solar cycle 24

    NASA Astrophysics Data System (ADS)

    Huang, Jianping; Hao, Yongqiang; Zhang, Donghe; Xiao, Zuo

    2016-07-01

    Following the extreme solar minimum during 2008-2009, solar activity keeps low in solar cycle 24 (SC24) and is making SC24 the weakest one of recent cycles. In this paper, using observations from Earth-orbiting satellites, we compare the solar extreme ultraviolet (EUV) irradiance between SC23 and SC24 and investigate the solar cycle change of linear dependence of EUV on the P ((F10.7 + F10.7A)/2) and Mg II core-to-wing ratio indices. The Bremen composite Mg II index is strongly correlated with P over the two solar cycles, while this is not the case for the Laboratory for Atmospheric and Space Physics (LASP) composite Mg II index, so we focus on the different dependence of EUV on the P and LASP Mg II indices. As a result we find that three coronal emissions (Fe XV at 28.4 nm and 41.7 nm and Fe XVI at 33.5 nm) brighten in SC24 relative to P; i.e., the magnitude of irradiance is higher than in SC23 at the same level of P. But relative to the LASP Mg II index, these emissions show no appreciable solar cycle differences. By contrast, the H I Lyman α at 121.6 nm dims in SC24 relative to the LASP Mg II but shows identical dependence on P in the two solar cycles. This result seems to contradict a well-accepted fact that chromospheric and transition region emissions are better represented by the Mg II index and coronal lines by F10.7. For the different solar cycle variability of EUV in SC24, whether it is caused by source changes on the Sun is still unclear, but we suggest that it needs to be considered in proxy modeling of the EUV irradiance and aeronomic studies.

  10. Absolute Ultraviolet Irradiance of the Moon from the LASP Lunar Albedo Measurement and Analysis from SOLSTICE (LLAMAS) Project

    NASA Astrophysics Data System (ADS)

    Snow, Martin; Holsclaw, Gregory M.; McClintock, William E.; Woods, Tom

    The Moon has been shown to be an extremely stable radiometric reference for calibration and long-term stability measurements of on-orbit sensors. The majority of the previous work on characterizing the lunar reflectance has been in the visible part of the spectrum using ground-based lunar images. The SOLar-STellar Irradiance Comparison Experiment (SOLSTICE) on the SOlar Radiation and Climate Experiment (SORCE) can be used to extend the lunar spectral irradiance dataset to include the 115-300 nm range. SOLSTICE can directly measure both the solar and lunar spectra from orbit, using the same optics and detectors. An observing campaign to map out the reflectance as a function of phase angle began in mid 2006 and continued through 2010. The geometry of SORCE's orbit is very favorable for lunar observations, and we have measurements spanning a range 0-170 ∘ in phase angle. In addition to Earth Observing Systems using the Moon for calibration, recent planetary missions have also made ultraviolet observations of the Moon during Earth flyby, and these SOLSTICE measurements can be useful in calibrating the absolute responsivity of those instruments as well.

  11. Extreme ultraviolet spectroscopy of low pressure helium microwave driven discharges

    NASA Astrophysics Data System (ADS)

    Espinho, Susana; Felizardo, Edgar; Tatarova, Elena; Alves, Luis Lemos

    2016-09-01

    Surface wave driven discharges are reliable plasma sources that can produce high levels of vacuum and extreme ultraviolet radiation (VUV and EUV). The richness of the emission spectrum makes this type of discharge a possible alternative source in EUV/VUV radiation assisted applications. However, due to challenging experimental requirements, publications concerning EUV radiation emitted by microwave plasmas are scarce and a deeper understanding of the main mechanisms governing the emission of radiation in this spectral range is required. To this end, the EUV radiation emitted by helium microwave driven plasmas operating at 2.45 GHz has been studied for low pressure conditions. Spectral lines from excited helium atoms and ions were detected via emission spectroscopy in the EUV/VUV regions. Novel data concerning the spectral lines observed in the 23 - 33 nm wavelength range and their intensity behaviour with variation of the discharge operational conditions are presented. The intensity of all the spectral emissions strongly increases with the microwave power delivered to the plasma up to 400 W. Furthermore, the intensity of all the ion spectral emissions in the EUV range decreases by nearly one order of magnitude as the pressure was raised from 0.2 to 0.5 mbar. Work funded by FCT - Fundacao para a Ciencia e a Tecnologia, under Project UID/FIS/50010/2013 and grant SFRH/BD/52412/2013 (PD-F APPLAuSE).

  12. Extreme ultraviolet narrow band emission from electron cyclotron resonance plasmas.

    PubMed

    Zhao, H Y; Zhao, H W; Sun, L T; Zhang, X Z; Wang, H; Ma, B H; Li, X X; Zhu, Y H; Sheng, L S; Zhang, G B; Tian, Y C

    2008-02-01

    Extreme ultraviolet lithography (EUVL) is considered as the most promising solution at and below dynamic random access memory 32 nm half pitch among the next generation lithography, and EUV light sources with high output power and sufficient lifetime are crucial for the realization of EUVL. However, there is no EUV light source completely meeting the requirements for the commercial application in lithography yet. Therefore, ECR plasma is proposed as a novel concept EUV light source. In order to investigate the feasibility of ECR plasma as a EUV light source, the narrow band EUV power around 13.5 nm emitted by two highly charged ECR ion sources -- LECR2M and SECRAL -- was measured with a calibrated EUV power measurement tool. Since the emission lines around 13.5 nm can be attributed to the 4d-5p transitions of Xe XI or the 4d-4f unresolved transition array of Sn VIII-XIII, xenon plasma was investigated. The dependence of the EUV throughput and the corresponding conversion efficiency on the parameters of the ion source, such as the rf power and the magnetic confinement configurations, were preliminarily studied.

  13. Four-mirror extreme ultraviolet (EUV) lithography projection system

    DOEpatents

    Cohen, Simon J; Jeong, Hwan J; Shafer, David R

    2000-01-01

    The invention is directed to a four-mirror catoptric projection system for extreme ultraviolet (EUV) lithography to transfer a pattern from a reflective reticle to a wafer substrate. In order along the light path followed by light from the reticle to the wafer substrate, the system includes a dominantly hyperbolic convex mirror, a dominantly elliptical concave mirror, spherical convex mirror, and spherical concave mirror. The reticle and wafer substrate are positioned along the system's optical axis on opposite sides of the mirrors. The hyperbolic and elliptical mirrors are positioned on the same side of the system's optical axis as the reticle, and are relatively large in diameter as they are positioned on the high magnification side of the system. The hyperbolic and elliptical mirrors are relatively far off the optical axis and hence they have significant aspherical components in their curvatures. The convex spherical mirror is positioned on the optical axis, and has a substantially or perfectly spherical shape. The spherical concave mirror is positioned substantially on the opposite side of the optical axis from the hyperbolic and elliptical mirrors. Because it is positioned off-axis to a degree, the spherical concave mirror has some asphericity to counter aberrations. The spherical concave mirror forms a relatively large, uniform field on the wafer substrate. The mirrors can be tilted or decentered slightly to achieve further increase in the field size.

  14. Multilayer reflective coatings for extreme-ultraviolet lithography

    SciTech Connect

    Montcalm, C., LLNL

    1998-03-10

    Multilayer mirror coatings which reflect extreme ultraviolet (EUV) radiation are a key enabling technology for EUV lithography. Mo/Si multilayers with reflectances of 67.5% at 13.4 nm are now routinely achieved and reflectances of 70 2% at 11.4 nm were obtained with MO/Be multilayers. High reflectance is achieved with careful control of substrate quality, layer thicknesses, multilayer materials, interface quality, and surface termination. Reflectance and film stress were found to be stable relative to the requirements for application to EUV lithography. The run-to-run reproducibility of the reflectance peak position was characterized to be better than 0.2%, providing the required wavelength matching among the seven multilayer-coated mirrors used in the present lithography system design. Uniformity of coating was improved to better than 0.5% across 150 mm diameter substrates. These improvements in EUV multilayer mirror technology will enable us to meet the stringent specifications for coating the large optical substrates for our next-generation EUV lithography system.

  15. The Extreme Ultraviolet (EUV) Instrument for the MAVEN Mission

    NASA Technical Reports Server (NTRS)

    Chamberlin, Phillip C.

    2012-01-01

    The Mars Atmosphere and Volatile Evolution Mission (MAVEN) will explore the variability in the planet's upper atmosphere and ionosphere that is dominated by interactions with the sun, specifically the high-energy photons in the soft X-ray and extreme ultraviolet wavelengths as well as interactions with the solar wind. Scientists will use MAVEN data to determine the current loss rate of volatile compounds from the Mars atmosphere, then extrapolate back in time in order to give historical estimations of state of the Mars atmosphere and climate, its ability to sustain liquid water, and the potential for the Martian habitability. The EUV instrument is critical in measuring the Space Weather driver of this atmospheric variability. It will directly observe a three EUV wavelength ranges and their variability due to solar flares (time scales of seconds to hours) as well as active region evolution (months), which will then act as proxies for a model to determine the entire 0.1-200 nm solar spectrum at all times during the MAVEN mission. These EUV measurements and models results will compliment the other instruments that will provide direct in-situ as well as remote sensing observations of the Martian atmospheric response to this solar driver. This presentation will be an introduction of this instrument and its science measurements and goals to the larger community, as well as a status report on its progress.

  16. Organometallic carboxylate resists for extreme ultraviolet with high sensitivity

    NASA Astrophysics Data System (ADS)

    Passarelli, James; Murphy, Michael; Re, Ryan Del; Sortland, Miriam; Hotalen, Jodi; Dousharm, Levi; Fallica, Roberto; Ekinci, Yasin; Neisser, Mark; Freedman, Daniel A.; Brainard, Robert L.

    2015-10-01

    We have developed organometallic carboxylate compounds [RnM)] capable of acting as negative-tone extreme ultraviolet (EUV) resists. The most sensitive of these resists contain antimony, three R-groups and two carboxylate groups, and carboxylate groups with polymerizable olefins (e.g., acrylate, methacrylate, or styrenecarboxylate). Evidence suggests that high sensitivity is achieved through the polymerization of olefins in the exposed region. We have performed a systematic sensitivity study of the molecules of the type RnM) where we have studied seven R groups, four main group metals (M), and three polymerizable carboxylate groups (O2CR‧). The sensitivity of these resists was evaluated using Emax or dose to maximum resist thickness after exposure and development. We found that the greatest predictor of sensitivity of the RnSb) resists is their level of polymerizable olefins. We mathematically define the polymerizable olefin loading (POL) as the ratio of the number of olefins versus the number of nonhydrogen atoms. Linear and log plots of Emax versus POL for a variety of molecules of the type R3Sb) lend insight into the behavior of these resists.

  17. An imaging extreme ultraviolet spectrometer for astrophysical investigations in space

    NASA Technical Reports Server (NTRS)

    Huber, M. C. E.; Timothy, J. G.; Morgan, J. S.; Lemaitre, G.; Tondello, G.

    1986-01-01

    A high-efficiency, extreme ultraviolet (EUV) imaging spectrometer has been constructed and tested. The spectrometer employs a concave toroidal grating illuminated at normal incidence in a Rowland circle mounting and has only one reflecting surface. The toroidal grating has been fabricated by a new technique employing an elastically deformable submaster grating which is replicated in a spherical form and then mechanically distorted to produce the desired aspect ratio of the toroidal surface for stigmatic imaging over the selected wavelength range. The fixed toroidal grating used in the spectrometer is then replicated from this surface. Photographic tests and initial photoelectric tests with a two-dimensional, pulse-counting detector system have verified the image quality of the toroidal grating at wavelengths near 600 A. The basic designs of two instruments employing the spectrometer for astrophysical investigations in space are described, namely, a high-resolution EUV spectroheliometer for studies of the solar chromosphere, transition region, and corona; and an EUV spectroscopic telescope for studies of nonsolar objects.

  18. Pattern inspection of etched multilayer extreme ultraviolet mask

    NASA Astrophysics Data System (ADS)

    Iida, Susumu; Hirano, Ryoichi; Amano, Tsuyoshi; Watanabe, Hidehiro

    2016-04-01

    Patterned mask inspection for an etched multilayer (ML) extreme ultraviolet mask was investigated. In order to optimize the mask structure from the standpoint of a pattern inspection the mask structure not only from the standpoint of a pattern inspection by using a projection electron microscope but also by using a projection electron microscope but also by considering the other fabrication processes using electron beam techniques such as critical dimension metrology and mask repair, we employed a conductive layer between the ML and substrate. By measuring the secondary electron emission coefficients of the candidate materials for the conductive layer, we evaluated the image contrast and the influence of the charging effect. In the cases of 40-pair ML, 16-nm-sized extrusion and intrusion defects were found to be detectable more than 10 sigma in half pitch 44, 40, and 32 nm line-and-space patterns. Reducing 40-pair ML to 20-pair ML degraded the image contrast and the defect detectability. However, by selecting B4C as a conductive layer, 16-nm-sized defects and etching residues remained detectable. The 16-nm-sized defects were also detected after the etched part was refilled with Si. A double-layer structure with 2.5-nm-thick B4C on metal film used as a conductive layer was found to have sufficient conductivity and also was found to be free from the surface charging effect and influence of native oxide.

  19. A small-scale extreme ultraviolet wave observed by SDO

    NASA Astrophysics Data System (ADS)

    Zheng, R.; Jiang, Y.; Hong, J.; Yang, J.; Bi, Y.; Yang, L.; Yang, D.

    2012-06-01

    "Extreme Ultraviolet (EUV) waves" are large-scale wavelike transients often associated with coronal mass ejections (CMEs). In this Letter, we present a possible detection of a fast-mode EUV wave associated with a mini-CME observed by the Solar Dynamics Observatory. On 2010 December 1, a small-scale EUV wave erupted near the disk center associated with a mini-CME, which showed all the low corona manifestations of a typical CME. The CME was triggered by the eruption of a mini-filament, with a typical length of about 30''. Although the eruption was tiny, the wave had the appearance of an almost semicircular front and propagated at a uniform velocity of 220-250km s-1 with very little angular dependence. The CME lateral expansion was asymmetric with an inclination toward north, and the southern footprints of the CME loops hardly shifted. The lateral expansion resulted in deep long-duration dimmings, showing the CME extent. Our analysis confirms that the small-scale EUV wave is a true wave, interpreted as the fast-mode wave.

  20. Multilayer coatings for optics in the extreme ultraviolet

    NASA Astrophysics Data System (ADS)

    Larruquert, Juan I.; Vidal-Dasilva, Manuela; García-Cortés, Sergio; Rodríguez-de Marcos, Luis; Fernández-Perea, Mónica; Aznárez, José A.; Méndez, José A.

    2011-02-01

    The strong absorption of materials in the extreme ultraviolet (EUV) above ~50 nm has precluded the development of efficient coatings. The development of novel coatings with improved EUV performance is presented. An extensive research was performed on the search and characterization of new materials with low absorption or high reflectance. Lanthanide series was found to be a source of materials with relatively low absorption in this range, where most materials in nature present a strong absorption. Other materials, such as SiO and B, have been found to have interesting properties for applications on EUV coatings. As a result, novel multilayers based on Yb, Al, and SiO have been developed with narrowband performance in the 50-92 nm range. In some cases, the difficulty of developing narrowband coatings in the EUV can be overcome by designing multilayers that address specific purposes, such as maximizing and/or minimizing the reflectance at two or more wavelengths or bands. In this direction, we are working towards the development of coatings that combine a relatively high reflectance in a desired EUV band with a low reflectance in another band, for applications in which the presence of the latter radiation may mask a weak EUV radiation source.

  1. Imaging characteristics of the Extreme Ultraviolet Explorer microchannel plate detectors

    NASA Technical Reports Server (NTRS)

    Vallerga, J. V.; Kaplan, G. C.; Siegmund, O. H. W.; Lampton, M.; Malina, R. F.

    1989-01-01

    The Extreme Ultraviolet Explorer (EUVE) satellite will conduct an all-sky survey over the wavelength range from 70 A to 760 A using four grazing-incidence telescopes and seven microchannel-plate (MCP) detectors. The imaging photon-counting MCP detectors have active areas of 19.6 cm2. Photon arrival position is determined using a wedge-and-strip anode and associated pulse-encoding electronics. The imaging characteristics of the EUVE flight detectors are presented including image distortion, flat-field response, and spatial differential nonlinearity. Also included is a detailed discussion of image distortions due to the detector mechanical assembly, the wedge-and-strip anode, and the electronics. Model predictions of these distortions are compared to preflight calibration images which show distortions less than 1.3 percent rms of the detector diameter of 50 mm before correction. The plans for correcting these residual detector image distortions to less than 0.1 percent rms are also presented.

  2. Extreme and far ultraviolet astronomy from Voyagers 1 and 2

    NASA Technical Reports Server (NTRS)

    Holberg, J. B.

    1990-01-01

    The instrumental characteristics, observational capabilities and scientific results of the Voyager 1 and 2 ultraviolet spectrometers are reviewed. These instruments provide current and ongoing access to low resolution spectra for a wide variety of astronomical sources in the 500 to 1700 A band. Observations of the brightest OB stars and hot subluminous stars as faint as V = 15 mag, are possible. In the EUV, at wavelengths shortward of 900 A, several new sources have been detected and a host of potential sources ruled out. In the far UV, particularly at wavelengths between 900 and 1200 A, Voyager is capable of observing a wide range of stellar and non-stellar sources. Such observations can often provide a valuable complement to IUE and other data sets at longer wavelengths. The Voyager spectrometers have proved remarkably stable photon counting instruments, capable of extremely long integration times. The long integration times, relatively large field of view, and location in the outer solar system also provide an ideal platform for observations of sources of faint diffuse emission, such as nebulae and the general sky background.

  3. Xe capillary target for laser-plasma extreme ultraviolet source

    SciTech Connect

    Inoue, Takahiro; Okino, Hideyasu; Nica, Petru Edward; Amano, Sho; Miyamoto, Shuji; Mochizuki, Takayasu

    2007-10-15

    A cryogenic Xe jet system with an annular nozzle has been developed in order to continuously fast supply a Xe capillary target for generating a laser-plasma extreme ultraviolet (EUV) source. The cooling power of the system was evaluated to be 54 W, and the temperature stability was {+-}0.5 K at a cooling temperature of about 180 K. We investigated experimentally the influence of pressure loss inside an annular nozzle on target formation by shortening the nozzle length. Spraying caused by cavitation was mostly suppressed by mitigating the pressure loss, and a focused jet was formed. Around a liquid-solid boundary, a solid-Xe capillary target (100/70 {mu}m {phi}) was formed with a velocity of {<=}0.01 m/s. Laser-plasma EUV generation was tested by focusing a Nd:YAG laser beam on the target. The results suggested that an even thinner-walled capillary target is required to realize the inertial confinement effect.

  4. Low extreme-ultraviolet luminosities impinging on protoplanetary disks

    SciTech Connect

    Pascucci, I.; Hendler, N. P.; Ricci, L.; Gorti, U.; Hollenbach, D.; Brooks, K. J.; Contreras, Y.

    2014-11-01

    The amount of high-energy stellar radiation reaching the surface of protoplanetary disks is essential to determine their chemistry and physical evolution. Here, we use millimetric and centimetric radio data to constrain the extreme-ultraviolet (EUV) luminosity impinging on 14 disks around young (∼2-10 Myr) sun-like stars. For each object we identify the long-wavelength emission in excess to the dust thermal emission, attribute that to free-free disk emission, and thereby compute an upper limit to the EUV reaching the disk. We find upper limits lower than 10{sup 42} photons s{sup –1} for all sources without jets and lower than 5 × 10{sup 40} photons s{sup –1} for the three older sources in our sample. These latter values are low for EUV-driven photoevaporation alone to clear out protoplanetary material in the timescale inferred by observations. In addition, our EUV upper limits are too low to reproduce the [Ne II] 12.81 μm luminosities from three disks with slow [Ne II]-detected winds. This indicates that the [Ne II] line in these sources primarily traces a mostly neutral wind where Ne is ionized by 1 keV X-ray photons, implying higher photoevaporative mass loss rates than those predicted by EUV-driven models alone. In summary, our results suggest that high-energy stellar photons other than EUV may dominate the dispersal of protoplanetary disks around sun-like stars.

  5. Extreme ultraviolet (EUV) and FUV calibration facility for special sensor ultraviolet limb imager (SSULI)

    NASA Astrophysics Data System (ADS)

    Boyer, Craig N.; Osterman, Steven N.; Thonnard, Stefan E.; McCoy, Robert P.; Williams, J. Z.; Parker, S. E.

    1994-09-01

    A facility for calibrating far ultraviolet and extreme ultraviolet instruments has recently been completed at the Naval Research Laboratory. Our vacuum calibration vessel is 2-m in length, 1.67-m in diameter, and can accommodate optical test benches up to 1.2-m wide by 1.5-m in length. A kinematically positioned frame with four axis precision pointing capability of 10 microns for linear translation and .01 degrees for rotation is presently used during vacuum optical calibration of SSULI. The chamber was fabricated from 304 stainless steel and polished internally to reduce surface outgassing. A dust-free environment is maintained at the rear of the vacuum chamber by enclosing the 2-m hinged vacuum access door in an 8 ft. by 8 ft. class 100 clean room. Every effort was made to obtain an oil-free environment within the vacuum vessel. Outgassing products are continually monitored with a 1 - 200 amu residual gas analyzer. An oil-free claw and vane pump evacuates the chamber to 10-2 torr through 4 in. diameter stainless steel roughing lines. High vacuum is achieved and maintained with a magnetically levitated 480 l/s turbo pump and a 3000 l/s He4 cryopump. Either of two vacuum monochrometers, a 1-m f/10.4 or a 0.2-m f/4.5 are coaxially aligned with the optical axis of the chamber and are used to select single UV atomic resonance lines from a windowless capillary or penning discharge UV light source. A calibrated channeltron detector is coaxially mounted with the SSULI detector during calibration. All vacuum valves, the cooling system for the cryopump compressor, and the roughing pump are controlled through optical fibers which are interfaced to a computer through a VME board. Optical fibers were chosen to ensure that complete electrical isolation is maintained between the computer and the vacuum system valves-solenoids and relays.

  6. Extreme ultraviolet spectra of solar flares from the extreme ultraviolet spectroheliograph SPIRIT onboard the CORONAS-F satellite

    SciTech Connect

    Shestov, S.; Kuzin, S.; Reva, A.

    2014-01-01

    We present detailed extreme ultraviolet (EUV) spectra of four large solar flares: M5.6, X1.3, X3.4, and X17 classes in the spectral ranges 176-207 Å and 280-330 Å. These spectra were obtained by the slitless spectroheliograph SPIRIT onboard the CORONAS-F satellite. To our knowledge, these are the first detailed EUV spectra of large flares obtained with a spectral resolution of ∼0.1 Å. We performed a comprehensive analysis of the obtained spectra and provide identification of the observed spectral lines. The identification was performed based on the calculation of synthetic spectra (the CHIANTI database was used), with simultaneous calculations of the differential emission measure (DEM) and density of the emitting plasma. More than 50 intense lines are present in the spectra that correspond to a temperature range of T = 0.5-16 MK; most of the lines belong to Fe, Ni, Ca, Mg, and Si ions. In all the considered flares, intense hot lines from Ca XVII, Ca XVIII, Fe XX, Fe XXII, and Fe XXIV are observed. The calculated DEMs have a peak at T ∼ 10 MK. The densities were determined using Fe XI-Fe XIII lines and averaged 6.5 × 10{sup 9} cm{sup –3}. We also discuss the identification, accuracy, and major discrepancies of the spectral line intensity prediction.

  7. Extreme Ultraviolet Emission Lines of Iron Fe XI-XIII

    NASA Astrophysics Data System (ADS)

    Lepson, Jaan; Beiersdorfer, P.; Brown, G. V.; Liedahl, D. A.; Brickhouse, N. S.; Dupree, A. K.

    2013-04-01

    The extreme ultraviolet (EUV) spectral region (ca. 20--300 Å) is rich in emission lines from low- to mid-Z ions, particularly from the middle charge states of iron. Many of these emission lines are important diagnostics for astrophysical plasmas, providing information on properties such as elemental abundance, temperature, density, and even magnetic field strength. In recent years, strides have been made to understand the complexity of the atomic levels of the ions that emit the lines that contribute to the richness of the EUV region. Laboratory measurements have been made to verify and benchmark the lines. Here, we present laboratory measurements of Fe XI, Fe XII, and Fe XIII between 40-140 Å. The measurements were made at the Lawrence Livermore electron beam ion trap (EBIT) facility, which has been optimized for laboratory astrophysics, and which allows us to select specific charge states of iron to help line identification. We also present new calculations by the Hebrew University - Lawrence Livermore Atomic Code (HULLAC), which we also utilized for line identification. We found that HULLAC does a creditable job of reproducing the forest of lines we observed in the EBIT spectra, although line positions are in need of adjustment, and line intensities often differed from those observed. We identify or confirm a number of new lines for these charge states. This work was supported by the NASA Solar and Heliospheric Program under Contract NNH10AN31I and the DOE General Plasma Science program. Work was performed in part under the auspices of the Department of Energy by Lawrence Livermore National Laboratory under Contract DEAC52-07NA27344.

  8. Four wave mixing experiments with extreme ultraviolet transient gratings

    PubMed Central

    Bencivenga, F.; Cucini, R.; Capotondi, F.; Battistoni, A.; Mincigrucci, R.; Giangrisostomi, E.; Gessini, A.; Manfredda, M.; Nikolov, I. P.; Pedersoli, E.; Principi, E.; Svetina, C.; Parisse, P.; Casolari, F.; Danailov, M. B.; Kiskinova, M.; Masciovecchio, C.

    2015-01-01

    Four wave mixing (FWM) processes, based on third-order non-linear light-matter interactions, can combine ultrafast time resolution with energy and wavevector selectivity, and enables to explore dynamics inaccessible by linear methods.1-7 The coherent and multi-wave nature of FWM approach has been crucial in the development of cutting edge technologies, such as silicon photonics,8 sub-wavelength imaging9 and quantum communications.10 All these technologies operate with optical wavelengths, which limit the spatial resolution and do not allow probing excitations with energy in the eV range. The extension to shorter wavelengths, that is the extreme ultraviolet (EUV) and soft-x-ray (SXR) range, will allow to improve the spatial resolution and to expand the excitation energy range, as well as to achieve elemental selectivity by exploiting core resonances.5-7,11-14 So far FWM applications at these wavelengths have been prevented by the absence of coherent sources of sufficient brightness and suitable experimental setups. Our results show how transient gratings, generated by the interference of coherent EUV pulses delivered by the FERMI free electron laser (FEL),15 can be used to stimulate FWM processes at sub-optical wavelengths. Furthermore, we have demonstrated the possibility to read the time evolution of the FWM signal, which embodies the dynamics of coherent excitations as molecular vibrations. This result opens the perspective for FWM with nanometer spatial resolution and elemental selectivity, which, for example, would enable the investigation of charge-transfer dynamics.5-7 The theoretical possibility to realize these applications have already stimulated dedicated and ongoing FEL developments;16-20 today our results show that FWM at sub-optical wavelengths is feasible and would be the spark to the further advancements of the present and new sources. PMID:25855456

  9. Solar extreme ultraviolet sensor and advanced langmuir probe

    NASA Technical Reports Server (NTRS)

    Voronka, N. R.; Block, B. P.; Carignan, G. R.

    1992-01-01

    For more than two decades, the staff of the Space Physics Research Laboratory (SPRL) has collaborated with the Goddard Space Flight Center (GSFC) in the design and implementation of Langmuir probes (LP). This program of probe development under the direction of Larry Brace of GSFC has evolved methodically with innovations to: improve measurement precision, increase the speed of measurement, and reduce the weight, size, power consumption and data rate of the instrument. Under contract NAG5-419 these improvements were implemented and are what characterize the Advanced Langmuir Probe (ALP). Using data from the Langmuir Probe on the Pioneer Venus Orbiter, Brace and Walter Hoegy of GSFC demonstrated a novel method of monitoring the solar extreme ultraviolet (EUV) flux. This led to the idea of developing a sensor similar to a Langmuir probe specifically designed to measure solar EUV (SEUV) that uses a similar electronics package. Under this contract, a combined instrument package of the ALP and SEUV sensor was to be designed, constructed, and laboratory tested. Finally the instrument was to be flight tested as part of sounding rocket experiment to acquire the necessary data to validate this method for possible use in future earth and planetary aeronomy missions. The primary purpose of this contract was to develop the electronics hardware and software for this instrument, since the actual sensors were suppied by GSFC. Due to budget constraints, only a flight model was constructed. These electronics were tested and calibrated in the laboratory, and then the instrument was integrated into the rocket payload at Wallops Flight Facility where it underwent environmental testing. After instrument recalibration at SPRL, the payload was reintegrated and launched from the Poker Flat Research Range near Fairbanks Alaska. The payload was successfully recovered and after refurbishment underwent further testing and developing to improve its performance for future use.

  10. NEW SOLAR EXTREME-ULTRAVIOLET IRRADIANCE OBSERVATIONS DURING FLARES

    SciTech Connect

    Woods, Thomas N.; Hock, Rachel; Eparvier, Frank; Jones, Andrew R.; Chamberlin, Phillip C.; Klimchuk, James A.; Didkovsky, Leonid; Judge, Darrell; Mariska, John; Warren, Harry; Schrijver, Carolus J.; Webb, David F.; Bailey, Scott; Tobiska, W. Kent

    2011-10-01

    New solar extreme-ultraviolet (EUV) irradiance observations from the NASA Solar Dynamics Observatory (SDO) EUV Variability Experiment provide full coverage in the EUV range from 0.1 to 106 nm and continuously at a cadence of 10 s for spectra at 0.1 nm resolution and even faster, 0.25 s, for six EUV bands. These observations can be decomposed into four distinct characteristics during flares. First, the emissions that dominate during the flare's impulsive phase are the transition region emissions, such as the He II 30.4 nm. Second, the hot coronal emissions above 5 MK dominate during the gradual phase and are highly correlated with the GOES X-ray. A third flare characteristic in the EUV is coronal dimming, seen best in the cool corona, such as the Fe IX 17.1 nm. As the post-flare loops reconnect and cool, many of the EUV coronal emissions peak a few minutes after the GOES X-ray peak. One interesting variation of the post-eruptive loop reconnection is that warm coronal emissions (e.g., Fe XVI 33.5 nm) sometimes exhibit a second large peak separated from the primary flare event by many minutes to hours, with EUV emission originating not from the original flare site and its immediate vicinity, but rather from a volume of higher loops. We refer to this second peak as the EUV late phase. The characterization of many flares during the SDO mission is provided, including quantification of the spectral irradiance from the EUV late phase that cannot be inferred from GOES X-ray diagnostics.

  11. Advanced materials for multilayer mirrors for extreme ultraviolet solar astronomy.

    PubMed

    Bogachev, S A; Chkhalo, N I; Kuzin, S V; Pariev, D E; Polkovnikov, V N; Salashchenko, N N; Shestov, S V; Zuev, S Y

    2016-03-20

    We provide an analysis of contemporary multilayer optics for extreme ultraviolet (EUV) solar astronomy in the wavelength ranges: λ=12.9-13.3  nm, λ=17-21  nm, λ=28-33  nm, and λ=58.4  nm. We found new material pairs, which will make new spaceborne experiments possible due to the high reflection efficiencies, spectral resolution, and long-term stabilities of the proposed multilayer coatings. In the spectral range λ=13  nm, Mo/Be multilayer mirrors were shown to demonstrate a better ratio of reflection efficiency and spectral resolution compared with the commonly used Mo/Si. In the spectral range λ=17-21  nm, a new multilayer structure Al/Si was proposed, which had higher spectral resolution along with comparable reflection efficiency compared with the commonly used Al/Zr multilayer structures. In the spectral range λ=30  nm, the Si/B4C/Mg/Cr multilayer structure turned out to best obey reflection efficiency and long-term stability. The B4C and Cr layers prevented mutual diffusion of the Si and Mg layers. For the spectral range λ=58  nm, a new multilayer Mo/Mg-based structure was developed; its reflection efficiency and long-term stability have been analyzed. We also investigated intrinsic stresses inherent for most of the multilayer structures and proposed possibilities for stress elimination.

  12. Multilayer coatings for the far and extreme ultraviolet

    NASA Astrophysics Data System (ADS)

    Larruquert, Juan I.; Vidal-Dasilva, Manuela; García-Cortés, Sergio; Rodríguez-de Marcos, Luis; Fernández-Perea, Mónica; Aznárez, José A.; Méndez, José A.

    2011-05-01

    We present the development of novel coatings for the far and extreme ultraviolet (FUV-EUV). In the EUV above ~50 nm, the strong absorption of materials has precluded the development of narrowband coatings. An extensive research has been performed on the search and characterization of new materials with low absorption; the lanthanide series has been found to be a source of materials with relatively low absorption in the range of interest. The discovery of a wealth of materials with relatively low EUV absorption is basic to develop efficient multilayers, particularly with narrowband properties. In this way, we have developed multilayers based on Yb, Al, and SiO with narrowband performance in the 50-92 nm range; these are first narrowband coatings peaked above 70 nm. Our recent research on multilayers based on Eu, Al, and SiO provide promising results, with an increase in the peak reflectance versus Yb/Al/SiO multilayers, along with a peak wavelength that can be extended up to ~100 nm. For applications where FUV-EUV narrowband coatings have not been able to be prepared, we can design multilayers that address specific purposes, such as maximizing the reflectance ratio at two wavelengths or bands. Our first goal in this direction is the development of coatings with high 102.6 nm/ 121.6 nm reflectance ratio. Calculations predict that a high reflectance at Lyman β with a good rejection at Lyman α can be obtained through multilayer coatings. We are at the beginning of experimental research for this goal.

  13. Solar extreme ultraviolet variability of the quiet Sun

    NASA Astrophysics Data System (ADS)

    Shakeri, F.; Teriaca, L.; Solanki, S. K.

    2015-09-01

    The last solar minimum has been unusually quiet compared to the previous minima (since space-based radiometric measurements are available). The Sun's magnetic flux was substantially lower during this minimum. Some studies also show that the total solar irradiance during the minimum after cycle 23 may have dropped below the values known from the two minima prior to that. For chromospheric and coronal radiation, the situation is less clear-cut. The Sun's 10.7 cm flux shows a decrease of ~4% during the solar minimum in 2008 compared to the previous minimum, but Ca ii K does not. Here we consider additional wavelengths in the extreme ultraviolet (EUV), specifically transitions of He i at 584.3 Å and O v at 629.7 Å, of which the CDS spectrometer aboard SOHO has been taking regular scans along the solar central meridian since 1996. We analysed this unique dataset to verify if and how the radiance distribution undergoes measurable variations between cycle minima. To achieve this aim we determined the radiance distribution of quiet areas around the Sun centre. Concentrating on the last two solar minima, we found out that there is very little variation in the radiance distribution of the chromospheric spectral line He i between these minima. The same analysis shows a modest, although significant, 4% variation in the radiance distribution of the TR spectral line O v. These results are comparable to those obtained by earlier studies employing other spectral features, and they confirm that chromospheric indices display a small variation, whereas in the transition region a more significant reduction of the brighter features is visible.

  14. Reconstruction of Solar Extreme Ultraviolet Flux 1740 - 2015

    NASA Astrophysics Data System (ADS)

    Svalgaard, Leif

    2016-11-01

    Solar extreme ultraviolet (EUV) radiation creates the conducting E-layer of the ionosphere, mainly by photo-ionization of molecular oxygen. Solar heating of the ionosphere creates thermal winds, which by dynamo action induce an electric field driving an electric current having a magnetic effect observable on the ground, as was discovered by G. Graham in 1722. The current rises and falls with the Sun, and thus causes a readily observable diurnal variation of the geomagnetic field, allowing us to deduce the conductivity and thus the EUV flux as far back as reliable magnetic data reach. High-quality data go back to the "Magnetic Crusade" of the 1830s and less reliable, but still usable, data are available for portions of the 100 years before that. J.R. Wolf and, independently, J.-A. Gautier discovered the dependence of the diurnal variation on solar activity, and today we understand and can invert that relationship to construct a reliable record of the EUV flux from the geomagnetic record. We compare that to the F_{10.7} flux and the sunspot number, and we find that the reconstructed EUV flux reproduces the F_{10.7} flux with great accuracy. On the other hand, it appears that the Relative Sunspot Number as currently defined is beginning to no longer be a faithful representation of solar magnetic activity, at least as measured by the EUV and related indices. The reconstruction suggests that the EUV flux reaches the same low (but non-zero) value at every sunspot minimum (possibly including Grand Minima), representing an invariant "solar magnetic ground state".

  15. Sources for beyond extreme ultraviolet lithography and water window imaging

    NASA Astrophysics Data System (ADS)

    O'Sullivan, Gerry; Li, Bowen; Dunne, Padraig; Hayden, Paddy; Kilbane, Deirdre; Lokasani, Ragava; Long, Elaine; Ohashi, Hayato; O'Reilly, Fergal; Sheil, John; Sheridan, Paul; Sokell, Emma; Suzuki, Chihiro; White, Elgiva; Higashiguchi, Takeshi

    2015-05-01

    Lithography tools are being built and shipped to semiconductor manufacturers for high volume manufacturing using extreme ultraviolet lithography (EUVL) at a wavelength of 13.5 nm. This wavelength is based on the availability of Mo/Si multilayer mirrors (MLMs) with a reflectivity of ˜70% at this wavelength. Moreover, the primary lithography tool manufacturer, ASML, has identified 6.x nm, where x˜7, as the wavelength of choice for so-called Beyond EUVL, based on the availability of La/B4C MLMs, with theoretical reflectance approaching 80% at this wavelength. The optimum sources have been identified as laser produced plasmas of Gd and Tb, as n = 4-n = 4 transitions in their ions emit strongly near this wavelength. However, to date, the highest conversion efficiency obtained, for laser to EUV energy emitted within the 0.6% wavelength bandwidth of the mirror is only 0.8%, pointing to the need to identify other potential sources or consider the selection of other wavelengths. At the same time, sources for other applications are being developed. Conventional sources for soft x-ray microscopy use H-like line emission from liquid nitrogen or carbon containing liquid jets which can be focused using zone plates. Recently the possibility of using MLMs with n = 4-n = 4 emission from a highly charged Bi plasma was proposed and subsequently the possibility of using Δn = 1 transitions in 3rd row transition elements was identified. All of these studies seek to identify spectral features that coincide with the reflectance characteristics of available MLMs, determine the conditions under which they are optimized and establish the maximum conversion efficiencies obtainable. Thus, there is a need for systematic studies of laser produced plasmas of a wide range of elements as some of the challenges are similar for all of these sources and some recent results will be presented.

  16. Extreme ultraviolet lithography: A few more pieces of the puzzle

    SciTech Connect

    Anderson, Christopher N.

    2009-05-20

    The work described in this dissertation has improved three essential components of extreme ultraviolet (EUV) lithography: exposure tools, photoresist, and metrology. Exposure tools. A field-averaging illumination stage is presented that enables nonuniform, high-coherence sources to be used in applications where highly uniform illumination is required. In an EUV implementation, it is shown that the illuminator achieves a 6.5% peak-to-valley intensity variation across the entire design field of view. In addition, a design for a stand-alone EUV printing tool capable of delivering 15 nm half-pitch sinusoidal fringes with available sources, gratings and nano-positioning stages is presented. It is shown that the proposed design delivers a near zero line-edge-rougness (LER) aerial image, something extremely attractive for the application of resist testing. Photoresist. Two new methods of quantifying the deprotection blur of EUV photoresists are described and experimentally demonstrated. The deprotection blur, LER, and sensitivity parameters of several EUV photoresists are quantified simultaneously as base weight percent, photoacid generator (PAG) weight percent, and post-exposure bake (PEB) temperature are varied. Two surprising results are found: (1) changing base weight percent does not significantly affect the deprotection blur of EUV photoresist, and (2) increasing PAG weight percent can simultaneously reduce LER and E-size in EUV photoresist. The latter result motivates the development of an EUV exposure statistics model that includes the effects of photon shot noise, the PAG spatial distribution, and the changing of the PAG distribution during the exposure. In addition, a shot noise + deprotection blur model is used to show that as deprotection blur becomes large relative to the size of the printed feature, LER reduction from improved counting statistics becomes dominated by an increase in LER due to reduced deprotection contrast. Metrology. Finally, this

  17. Changes of solar extreme ultraviolet spectrum in solar cycle 24

    NASA Astrophysics Data System (ADS)

    Hao, Yongqiang; Zhang, Donghe; Xiao, Zuo; Huang, Jianping

    2016-07-01

    Following the extreme solar minimum during 2008 - 2009, solar activity keeps low in solar cycle 24 (SC24) and is making SC24 the weakest one of recent cycles. In this paper, we compare the solar EUV spectral irradiance between SC23 and SC24, using the measurements by the Solar EUV Experiment (SEE) on the Thermospheric Ionospheric Mesospheric Energy and Dynamics (TIMED) spacecraft. The EUV spectrum varies with solar activity, and is in general a linear function of a proxy index P= (F10.7 + F10.7A)/2. However, we find the slope of this function, i.e., the change rate of irradiance at each wavelength with P, differs between SC23 and SC24. Consequently, at a given P level, the irradiance in SC24 is higher at wavelength of 30 - 50 nm, but lower at 60 - 120 nm and longward of 140 nm; the inter-cycle variation of EUV irradiance at some wavelengths can be 30 - 40% in absolute flux. We further examine 38 most intense emission lines and find that, taking P as a reference, most of the bright coronal lines get stronger in SC24 and, by contrast, those from the chromosphere and transition region have less variability in SC24. We therefore suggest that, the empirical relation between solar EUV and P, which is derived from observations in previous solar cycles, may not adapt to SC24. The changes in EUV spectrum need to be considered in the models for aeronomic study, especially those using F10.7 index as an input parameter.

  18. EDITORIAL: Extreme Ultraviolet Light Sources for Semiconductor Manufacturing

    NASA Astrophysics Data System (ADS)

    Attwood, David

    2004-12-01

    The International Technology Roadmap for Semiconductors (ITRS) [1] provides industry expectations for high volume computer chip fabrication a decade into the future. It provides expectations to anticipated performance and requisite specifications. While the roadmap provides a collective projection of what international industry expects to produce, it does not specify the technology that will be employed. Indeed, there are generally several competing technologies for each two or three year step forward—known as `nodes'. Recent successful technologies have been based on KrF (248 nm), and now ArF (193 nm) lasers, combined with ultraviolet transmissive refractive optics, in what are known as step and scan exposure tools. Less fortunate technologies in the recent past have included soft x-ray proximity printing and, it appears, 157 nm wavelength F2 lasers. In combination with higher numerical aperture liquid emersion optics, 193 nm is expected to be used for the manufacture of leading edge chip performance for the coming five years. Beyond that, starting in about 2009, the technology to be employed is less clear. The leading candidate for the 2009 node is extreme ultraviolet (EUV) lithography, however this requires that several remaining challenges, including sufficient EUV source power, be overcome in a timely manner. This technology is based on multilayer coated reflective optics [2] and an EUV emitting plasma. Following Moore's Law [3] it is expected, for example, that at the 2009 `32 nm node' (printable patterns of 32 nm half-pitch), isolated lines with 18 nm width will be formed in resist (using threshold effects), and that these will be further narrowed to 13 nm in transfer to metalized electronic gates. These narrow features are expected to provide computer chips of 19 GHz clock frequency, with of the order of 1.5 billion transistors per chip [1]. This issue of Journal of Physics D: Applied Physics contains a cluster of eight papers addressing the critical

  19. Angular distribution of ions and extreme ultraviolet emission in laser-produced tin droplet plasma

    SciTech Connect

    Chen, Hong; Duan, Lian; Lan, Hui; Wang, Xinbing Chen, Ziqi; Zuo, Duluo; Lu, Peixiang

    2015-05-21

    Angular-resolved ion time-of-flight spectra as well as extreme ultraviolet radiation in laser-produced tin droplet plasma are investigated experimentally and theoretically. Tin droplets with a diameter of 150 μm are irradiated by a pulsed Nd:YAG laser. The ion time-of-flight spectra measured from the plasma formed by laser irradiation of the tin droplets are interpreted in terms of a theoretical elliptical Druyvesteyn distribution to deduce ion density distributions including kinetic temperatures of the plasma. The opacity of the plasma for extreme ultraviolet radiation is calculated based on the deduced ion densities and temperatures, and the angular distribution of extreme ultraviolet radiation is expressed as a function of the opacity using the Beer–Lambert law. Our results show that the calculated angular distribution of extreme ultraviolet radiation is in satisfactory agreement with the experimental data.

  20. Ultraviolet photolysis of HCHO: absolute HCO quantum yields by direct detection of the HCO radical photoproduct.

    PubMed

    Carbajo, Paula Gorrotxategi; Smith, Shona C; Holloway, Anne-Louise; Smith, Carina A; Pope, Francis D; Shallcross, Dudley E; Orr-Ewing, Andrew J

    2008-12-04

    Absolute quantum yields for the radical (H + HCO) channel of HCHO photolysis, Phi(HCO), have been measured for the tropospherically relevant range of wavelengths (lambda) between 300 and 330 nm. The HCO photoproduct was directly detected by using a custom-built, combined ultra-violet (UV) absorption and cavity ring down (CRD) detection spectrometer. This instrument was previously employed for high-resolution (spectral resolution approximately 0.0035 nm) measurements of absorption cross-sections of HCHO, sigma(HCHO)(lambda), and relative HCO quantum yields. Absolute Phi(HCO) values were measured at seven wavelengths, lambda = 303.70, 305.13, 308.87, 314.31, 320.67, 325.59, and 329.51 nm, using an independent calibration technique based on the simultaneous UV photolysis of HCHO and Cl(2). These Phi(HCO) measurements display greater variability as a function of wavelength than the current NASA-JPL recommendations for Phi(HCO). The absolute Phi(HCO)(lambda) determinations and previously measured sigma(HCHO)(lambda) were used to scale an extensive set of relative HCO yield measurements. The outcome of this procedure is a full suite of data for the product of the absolute radical quantum yield and HCHO absorption cross-section, Phi(HCO)(lambda)sigma(HCHO)(lambda), at wavelengths from 302.6 to 331.0 nm with a wavelength resolution of 0.005 nm. This product of photochemical parameters is combined with high-resolution solar photon flux data to calculate the integrated photolysis rate of HCHO to the radical (H + HCO) channel, J(HCO). Comparison with the latest NASA-JPL recommendations, reported at 1 nm wavelength resolution, suggests an increased J(HCO) of 25% at 0 degrees solar zenith angle (SZA) increasing to 33% at high SZA (80 degrees). The differences in the calculated photolysis rate compared with the current HCHO data arise, in part, from the higher wavelength resolution of the current data set and highlight the importance of using high-resolution spectroscopic

  1. EUNIS: Extreme-Ultraviolet Normal-Incidence Spectrometer

    NASA Astrophysics Data System (ADS)

    Thomas, R. J.; Davila, J. M.

    2001-05-01

    GSFC is in the process of assembling an Extreme-Ultraviolet Normal-Incidence Spectrometer called EUNIS, to be flown as a sounding rocket payload. This instrument builds on the many technical innovations pioneered by our highly successful SERTS experiment, which has now flown a total of ten times, most recently last summer. The new design will have somewhat improved spatial and spectral resolutions, as well as two orders of magnitude greater sensitivity, permitting high signal/noise EUV spectroscopy with a temporal resolution near 1~second for the first time ever. In order to achieve such high time cadence, a novel detector system is being developed, based on Active-Pixel-Sensor electronics, a key component of our design. The high sensitivity of EUNIS will allow entirely new studies of transient coronal phenomena, such as the rapid loop dynamics seen by TRACE, and searches for non-thermal motions indicative of magnetic reconnection or wave heating. Another observing mode will be to raster a two dimensional region on the disk, giving data on much larger solar areas than could be covered with SERTS. The increased sensitivity will also permit useful EUV spectra at heights of 2--3~Rsun above the limb, where the transition between the static corona and the solar wind might occur. In addition, the new design features two independent optical systems, which more than double the spectral bandwidth covered on each flight. Its 300--370Å bandpass includes He~II 304Å and strong lines from Fe~XI--XVI, extending the current SERTS range of 300--355Å to further improve our ongoing series of calibration under-flights for SOHO/CDS and EIT. The second bandpass of 170--230Å has a sequence of very strong Fe~IX--XIV lines, and will allow under-flight support for two more channels on SOHO/EIT, two channels on TRACE, one on Solar-B/EIS, and all four channels on the STEREO/EUVI instrument. First flight of the new EUNIS payload is scheduled for 2002 October from White Sands Missile Range

  2. Extreme Ultraviolet Variability Experiment (EVE) Multiple EUV Grating Spectrographs (MEGS): Radiometric Calibrations and Results

    NASA Technical Reports Server (NTRS)

    Hock, R. A.; Woods, T. N.; Crotser, D.; Eparvier, F. G.; Woodraska, D. L.; Chamberlin, P. C.; Woods, E. C.

    2010-01-01

    The NASA Solar Dynamics Observatory (SDO), scheduled for launch in early 2010, incorporates a suite of instruments including the Extreme Ultraviolet Variability Experiment (EVE). EVE has multiple instruments including the Multiple Extreme ultraviolet Grating Spectrographs (MEGS) A, B, and P instruments, the Solar Aspect Monitor (SAM), and the Extreme ultraviolet SpectroPhotometer (ESP). The radiometric calibration of EVE, necessary to convert the instrument counts to physical units, was performed at the National Institute of Standards and Technology (NIST) Synchrotron Ultraviolet Radiation Facility (SURF III) located in Gaithersburg, Maryland. This paper presents the results and derived accuracy of this radiometric calibration for the MEGS A, B, P, and SAM instruments, while the calibration of the ESP instrument is addressed by Didkovsky et al. . In addition, solar measurements that were taken on 14 April 2008, during the NASA 36.240 sounding-rocket flight, are shown for the prototype EVE instruments.

  3. Study of impurities in the Tandem Mirror Experiment using extreme-ultraviolet spectroscopy

    SciTech Connect

    Strand, O.T.

    1982-05-12

    Impurities in the Tandem Mirror Experiment (TMX) have been studied using extreme ultraviolet spectroscopy. Three time-resolving absolutely-calibrated normal-incidence monochromators, one on each section of TMX, were used to study the impurity emissions in the wavelength range of 300 A to 1600 A. The instruments on the east end cell and central cell were each capable of obtaining spatially-resolved profiles from 22 chords of the plasma simultaneously while the instrument on the west end cell monitored the central chord. The impurities identified in TMX were carbon, nitrogen, oxygen, and titanium. Emphasis was placed upon determining the impurity densities and radiated power losses of the central cell; results indicate that the impurity concentrations were low - less than 0.4% for each species - and that less than 10% of the total net trapped neutral beam power was lost to radiation. The use of titanium gettering on the central cell walls was observed to decrease the brightnesses of singly- and doubly-ionized carbon and oxygen in the central cell plasma. In the end cells, oxygen was the main impurity with a concentration of about 1.5% and was injected by the neutral beams; the other impurities had concentrations of about 0.5%. Radiation losses from the end cells were negligible.

  4. Absolute intensities of the vacuum ultraviolet spectra in oxide etch plasma processing discharges

    SciTech Connect

    WOODWORTH,JOSEPH R.; RILEY,MERLE E.; AMATUCCI,VINCENT A.; HAMILTON,THOMAS W.; ARAGON,BEN P.

    2000-05-01

    In this paper, the authors report the absolute intensities of ultraviolet light between 4.9 eV and 24 eV ( 250 nm to 50 mn ) striking a silicon wafer in a number of oxide-etch processing discharges. The emphasis is on photons with energies greater than 8.8 eV, which have enough energy to damage SiO{sub 2}. These discharges were in an inductively-driven Gaseous Electronics Conference reference cell which had been modified to more closely resemble commercial etching tools. Comparisons of measurements made through a side port in the cell and through a hole in the wafer indicate that the VUV light in these discharges is strongly trapped. For the pure halocarbon gases examined in these experiments (C{sub 2}F{sub 6}, CHF{sub 3}, C{sub 4}F{sub 8}), the fluxes of VUV photons to the wafer varied from 1 x 10{sup 15} to 3 x 10{sup 15} photons/cm{sup 2} sec or equivalently from 1.5 to 5 mW/cm{sup 2}. These measurements imply that 0.1% to 0.3% of the rf source power to these discharges ends up hitting the wafer as VUV photons for the typical 20 mT, 200 W rf discharges. For typical ashing discharges containing pure oxygen, the VUV intensities are slightly higher--about 8 mW/cm{sup 2} . As argon or hydrogen diluents are added to the fluorocarbon gases, the VUV intensities increase dramatically, with a 10/10/10 mixture of Ar/C{sub 2}F{sub 6}/H{sub 2} yielding VUV fluxes on the wafer 26 mW/cm{sup 2} and pure argon discharges yielding 52 mW/cm{sup 2} . Adding an rf bias to the wafer had only a small effect on the VUV observed through a side-port of the GEC cell.

  5. Note: On the wavelength dependence of the intensity calibration factor of extreme ultraviolet spectrometer determined with profile measurement of bremsstrahlung continuum

    SciTech Connect

    Yamaguchi, N.; Morita, S.; Dong, C. F.; Goto, M.; Maezawa, H.; Miyauchi, H.

    2015-06-15

    The absolute calibration factor of extreme ultraviolet spectroscopic instrument which has recently been determined from absolute radiation profile measurement of bremsstrahlung continuum has been investigated by comparing the calculated diffraction efficiency of grating. An overall tendency of the wavelength dependence of the calibration factor from 40 Å to 500 Å can be reproduced by that of the grating efficiency, especially the agreement between the measured calibration factor and the calculated grating efficiency has been found to be fairly good for the wavelength range 200 Å-500 Å.

  6. Three new extreme ultraviolet spectrometers on NSTX-U for impurity monitoring

    NASA Astrophysics Data System (ADS)

    Weller, M. E.; Beiersdorfer, P.; Soukhanovskii, V. A.; Magee, E. W.; Scotti, F.

    2016-11-01

    Three extreme ultraviolet (EUV) spectrometers have been mounted on the National Spherical Torus Experiment-Upgrade (NSTX-U). All three are flat-field grazing-incidence spectrometers and are dubbed X-ray and Extreme Ultraviolet Spectrometer (XEUS, 8-70 Å), Long-Wavelength Extreme Ultraviolet Spectrometer (LoWEUS, 190-440 Å), and Metal Monitor and Lithium Spectrometer Assembly (MonaLisa, 50-220 Å). XEUS and LoWEUS were previously implemented on NSTX to monitor impurities from low- to high-Z sources and to study impurity transport while MonaLisa is new and provides the system increased spectral coverage. The spectrometers will also be a critical diagnostic on the planned laser blow-off system for NSTX-U, which will be used for impurity edge and core ion transport studies, edge-transport code development, and benchmarking atomic physics codes.

  7. Laser triggered Z-pinch broadband extreme ultraviolet source for metrology

    SciTech Connect

    Tobin, I.; Lunney, J. G.; Juschkin, L.; Sidelnikov, Y.; O'Reilly, F.; Sokell, E.; Sheridan, P.

    2013-05-20

    We compare the extreme ultraviolet emission characteristics of tin and galinstan (atomic %: Ga: 78.35, In: 14.93, Sn: 6.72) between 10 nm and 18 nm in a laser-triggered discharge between liquid metal-coated electrodes. Over this wavelength range, the energy conversion efficiency for galinstan is approximately half that of tin, but the spectrum is less strongly peaked in the 13-15 nm region. The extreme ultraviolet source dimensions were 110 {+-} 25 {mu}m diameter and 500 {+-} 125 {mu}m length. The flatter spectrum, and -19 Degree-Sign C melting point, makes this galinstan discharge a relatively simple high radiance extreme ultraviolet light source for metrology and scientific applications.

  8. Fabrication of high-resolution zone plates with wideband extreme-ultraviolet holography

    SciTech Connect

    Solak, Harun H.; David, Christian; Gobrecht, Jens

    2004-10-04

    We report an achromatic holographic method to fabricate high-resolution x-ray optics using coherent extreme-ultraviolet radiation from an undulator source. The interference pattern between two spherical beams, which are created using Fresnel zone plates, is recorded to produce a higher-resolution zone plate. Analytical and simulation results showing the formation of the zone plate pattern was confirmed experimentally with the production and testing of a lens with 60-nm outermost zone width. The combination of extreme-ultraviolet light, which exposes photoresists with practically no proximity effect, and holography, which guarantees the accurate placement of zones, addresses the main difficulties faced in the improvement of the resolution of x-ray lenses. Holography with extreme-ultraviolet light has the potential to produce lenses with sub-10-nm resolution.

  9. [Theoretical analysis and experimental measurement for secondary electron yield of microchannel plate in extreme ultraviolet region].

    PubMed

    Li, Min; Ni, Qi-liang; Dong, Ning-ning; Chen, Bo

    2010-08-01

    Photon counting detectors based on microchannel plate have widespread applications in astronomy. The present paper deeply studies secondary electron of microchannel plate in extreme ultraviolet. A theoretical model describing extreme ultraviolet-excited secondary electron yield is presented, and the factor affecting on the secondary electron yields of both electrode and lead glass which consist of microchannel plate is analyzed according to theoretical formula derived from the model. The result shows that the higher secondary electron yield is obtained under appropriate condition that the thickness of material is more than 20 nm and the grazing incidence angle is larger than the critical angle. Except for several wavelengths, the secondary electron yields of both electrode and lead glass decrease along with the increase in the wavelength And also the quantum efficiency of microchannel plate is measured using quantum efficiency test set-up with laser-produced plasmas source as an extreme ultraviolet radiation source, and the result of experiment agrees with theoretical analysis.

  10. Extreme ultraviolet reflectivity studies of gold on glass and metal substrates

    NASA Technical Reports Server (NTRS)

    Jelinsky, Sharon R.; Malina, Roger F.; Jelinsky, Patrick

    1988-01-01

    The paper reports measurements of the extreme ultraviolet reflectivity of gold from 44 to 920 A at grazing incidence. Gold was deposited using vacuum evaporation and electroplating on substrates of glass and polished nickel, respectively. Measurements are also presented of the extreme ultraviolet reflectivity of electroless nickel in the same wavelength region, where one of the polished nickel substrates was used as a sample. Derived optical constants for evaporated and electroplated gold and electroless nickel are presented. Additional studies of the effects of various contaminants on the EUV reflectivity are also reported. The variations of the optical constants are discussed in terms of density variations, surface roughness and contamination effects. These results ae reported as part of studies for the Extreme Ultraviolet Explorer satellite program to determine acceptance criteria for the EUV optics, contamination budgets and calibration plans.

  11. Atmosphere and water loss from early Mars under extreme solar wind and extreme ultraviolet conditions.

    PubMed

    Terada, Naoki; Kulikov, Yuri N; Lammer, Helmut; Lichtenegger, Herbert I M; Tanaka, Takashi; Shinagawa, Hiroyuki; Zhang, Tielong

    2009-01-01

    The upper limits of the ion pickup and cold ion outflow loss rates from the early martian atmosphere shortly after the Sun arrived at the Zero-Age-Main-Sequence (ZAMS) were investigated. We applied a comprehensive 3-D multi-species magnetohydrodynamic (MHD) model to an early martian CO(2)-rich atmosphere, which was assumed to have been exposed to a solar XUV [X-ray and extreme ultraviolet (EUV)] flux that was 100 times higher than today and a solar wind that was about 300 times denser. We also assumed the late onset of a planetary magnetic dynamo, so that Mars had no strong intrinsic magnetic field at that early period. We found that, due to such extreme solar wind-atmosphere interaction, a strong magnetic field of about approximately 4000 nT was induced in the entire dayside ionosphere, which could efficiently protect the upper atmosphere from sputtering loss. A planetary obstacle ( approximately ionopause) was formed at an altitude of about 1000 km above the surface due to the drag force and the mass loading by newly created ions in the highly extended upper atmosphere. We obtained an O(+) loss rate by the ion pickup process, which takes place above the ionopause, of about 1.5 x 10(28) ions/s during the first < or =150 million years, which is about 10(4) times greater than today and corresponds to a water loss equivalent to a global martian ocean with a depth of approximately 8 m. Consequently, even if the magnetic protection due to the expected early martian magnetic dynamo is neglected, ion pickup and sputtering were most likely not the dominant loss processes for the planet's initial atmosphere and water inventory. However, it appears that the cold ion outflow into the martian tail, due to the transfer of momentum from the solar wind to the ionospheric plasma, could have removed a global ocean with a depth of 10-70 m during the first < or =150 million years after the Sun arrived at the ZAMS.

  12. Sun's image in the extreme ultraviolet radiation emitted from the corona

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The Skylab space station's Extreme Ultraviolet monitor is a closed loop television system that permitted man for the first time to watch the Sun's image in the extreme ultraviolet radiation emitted from its million-degree outer atmosphere, the corona. This photograph shows a view of the TV scope made by Scientist-Astronaut Owen K. Garriott, Skylab 3 science pilot, on August 15, 1973. Dr. Garriott made this picture with a Land-Polaroid SX-70 camera - the first time that any Polaroid camera has been used in space.

  13. Wave-mixing with high-order harmonics in extreme ultraviolet region

    SciTech Connect

    Dao, Lap Van; Dinh, Khuong Ba; Le, Hoang Vu; Gaffney, Naylyn; Hannaford, Peter

    2015-01-12

    We report studies of the wave-mixing process in the extreme ultraviolet region with two near-infrared driving and controlling pulses with incommensurate frequencies (at 1400 nm and 800 nm). A non-collinear scheme for the two beams is used in order to spatially separate and to characterise the properties of the high-order wave-mixing field. We show that the extreme ultraviolet frequency mixing can be treated by perturbative, very high-order nonlinear optics; the modification of the wave-packet of the free electron needs to be considered in this process.

  14. Flat field response of the microchannel plate detectors used on the Extreme Ultraviolet Explorer

    NASA Technical Reports Server (NTRS)

    Vallerga, J. V.; Gibson, J. L.; Siegmund, O. H. W.; Vedder, P. W.

    1989-01-01

    The results of the extreme ultraviolet (EUV) flat field calibrations of two of the flight detectors to be flown on the Extreme Ultraviolet Explorer Satellite (EUVE) are presented. Images of about 40 million detected events binned 512 by 512 are sufficient to show microchannel plate fixed pattern noise such as hexagonal microchannel multifiber bundle interfaces, 'dead' spots, edge distortion, and differential nonlinearity. Differences due to photocathode material and dependencies on EUV wavelength are also described. Over large spatial scales, the detector response is flat to better than 10 percent of the mean response, but, at spatial scales less than 1 mm, the variations from the mean can be as large as 20 percent.

  15. Extreme ultraviolet source using a forced recombination process in lithium plasma generated by a pulsed laser

    SciTech Connect

    Nagano, Akihisa; Inoue, Takahiro; Nica, Petru-Edward; Amano, Sho; Miyamoto, Shuji; Mochizuki, Takayasu

    2007-04-09

    An extreme ultraviolet source having a tamper has been studied. This target scheme recombines forcedly lithium ions by low temperature electrons from the tamper, converting Li{sup 3+} rapidly to excited Li{sup 2+} which emit intense 1s-2p Lyman {alpha} emissions at 13.5 nm. A strong 13.5 nm emission appeared at 20-30 ns after the time of laser peak within a small space volume near the tamper. The authors obtained an enhancement of extreme ultraviolet conversion efficiency by a factor of about 2 with the tamper against that of a target without the tamper at the same laser irradiation condition00.

  16. Large-solid-angle illuminators for extreme ultraviolet lithography with laser plasmas

    SciTech Connect

    Kubiak, G.D.; Tichenor, D.A.; Sweatt, W.C.; Chow, W.W.

    1995-06-01

    Laser Plasma Sources (LPSS) of extreme ultraviolet radiation are an attractive alternative to synchrotron radiation sources for extreme ultraviolet lithography (EUVL) due to their modularity, brightness, and modest size and cost. To fully exploit the extreme ultraviolet power emitted by such sources, it is necessary to capture the largest possible fraction of the source emission half-sphere while simultaneously optimizing the illumination stationarity and uniformity on the object mask. In this LDRD project, laser plasma source illumination systems for EUVL have been designed and then theoretically and experimentally characterized. Ellipsoidal condensers have been found to be simple yet extremely efficient condensers for small-field EUVL imaging systems. The effects of aberrations in such condensers on extreme ultraviolet (EUV) imaging have been studied with physical optics modeling. Lastly, the design of an efficient large-solid-angle condenser has been completed. It collects 50% of the available laser plasma source power at 14 nm and delivers it properly to the object mask in a wide-arc-field camera.

  17. Effect of xenon bombardment on ruthenium-coated grazing incidence collector mirror lifetime for extreme ultraviolet lithography

    SciTech Connect

    Nieto, Martin; Allain, Jean-Paul; Titov, Vladimir; Hendricks, Matthew R.; Hassanein, Ahmed; Rokusek, Daniel; Chrobak, Christopher; Tarrio, Charles; Barad, Yaniv; Grantham, Steven; Lucatorto, Thomas B.; Rice, Brian

    2006-09-01

    The effect of energetic xenon ion bombardment on the extreme ultraviolet (EUV) reflectivity performance of mirrors is of vital importance for the performance of discharge- and laser-produced plasma extreme ultraviolet lithography sources. To study these effects, we measured absolute and relative reflectivities at the National Institute of Standards and Technology and the Interaction of Materials with Particles and Components Testing facility to quantify the effects of singly ionized Xe ion bombardment on the reflectivity of Ru EUV collector mirrors. Results show that unity sputtering is reached at Xe{sup +} energies near 400-500 eV. The Xe{sup +}-induced sputter yield decreases an order of magnitude with only a 60% decrease in energy. Incident angle-dependent data of Xe{sup +} bombardment show that the sputter yield is weakly dependent on angle at energies near 1 keV. Dynamic measurements of in situ EUV reflectivity during Xe{sup +} irradiation show that the oxygen state of the reflecting mirror has a significant effect on reflectivity performance. For example, 13.5 nm light reflecting from an oxygen-rich mirror results in over a 40% loss in reflectivity. These studies also found that the surface roughness increased only at the atomic scale (subnanometer scale) when exposed to energetic Xe{sup +} and thus did not contribute to EUV reflectivity losses except for cases of very high fluences (>10{sup 16} cm{sup -2})

  18. Coherent Extreme Ultraviolet Generation and Surface Studies Using Ultraviolet Excimer Lasers.

    DTIC Science & Technology

    1986-02-10

    are detected by a two-stage multi-channel plate detector, (MCP-Chevron type), which is connected to a transient digitizer (Tektronix 7912 AD). The...Supplement). 43. "Ultraviolet Excitation of Cryogenic Rare-Gas Chlorine Solutions ," H. Jara, M. Shahidi, H. Pummer, H. Egger, akd C. K. Rhodes, in...like core. In principle, these equations are nonlinear in the applied electromagnetic field. We observe that the incident electromagentic field has a

  19. IUE spectra of Feige 4, a suspected source of extreme-ultraviolet radiation

    NASA Technical Reports Server (NTRS)

    Holm, A. V.; Boggess, A.

    1982-01-01

    IUE spectra are presented for Feige 4, a DB-type white dwarf. The observed energy distribution is in good agreement with that predicted by a model atmosphere with an effective temperature of 15,500 K and having extremely low hydrogen and metal abundances. These results are evidence against Feige 4 being the source of the apparent extreme-ultraviolet signal detected by Prognoz 6.

  20. SOLAR-B Mission Extreme Ultraviolet (EUV) Imaging Spectrometer (EIS) Instrument Components

    NASA Technical Reports Server (NTRS)

    Doschek, George A.

    2001-01-01

    This Monthly Progress Report covers the reporting period through June 2001, Phase C/D, Detailed Design and Development Through Launch Plus Thirty Days, for selected components and subsystems of the Extreme ultraviolet Imaging Spectrometer (EIS) instrument, hereafter referred to as EIS Instrument Components. This document contains the program status through the reporting period and forecasts the status for the upcoming reporting period.

  1. SOLAR-B Mission Extreme Ultraviolet (EUV) Imaging Spectrometer (EIS) Instrument Components

    NASA Technical Reports Server (NTRS)

    Doschek, George A.

    2001-01-01

    This Monthly Progress Report covers the reporting period July 2001 of the Detailed Design and Development through Launch plus Thirty Days, Phase C/D, for selected components and subsystems of the Extreme Ultraviolet Imaging Spectrometer (EIS) instrument, hereafter referred to as EIS Instrument Components. This document contains the program status through the reporting period and forecasts the status for the upcoming reporting period.

  2. Solar-B Mission Extreme Ultraviolet (EUV) Imaging Spectrometer (EIS) Instrument Components

    NASA Technical Reports Server (NTRS)

    Doschek, George A.

    2002-01-01

    This Monthly Progress Report covers the reporting period August 2002 of the Detailed Design and Development through Launch plus Thirty Days, Phase C/D, for selected components and subsystems of the Extreme ultraviolet Imaging Spectrometer (EIS) instrument, hereafter referred to as EIS Instrument Components. This document contains the program status through the reporting period and forecasts the status for the upcoming reporting period.

  3. Comparing Vacuum and Extreme Ultraviolet Radiation for Postionization of Laser Desorbed Neutrals from Bacterial Biofilms and Organic Fullerene

    SciTech Connect

    Gaspera, Gerald L.; Takahashi, Lynelle K.; Zhou, Jia; Ahmed, Musahid; Moored, Jerry F.; Hanley, Luke

    2010-12-08

    Vacuum and extreme ultraviolet radiation from 8 - 24 eV generated at a synchrotron was used to postionize laser desorbed neutrals of antibiotic-treated biofilms and a modified fullerene using laser desorption postionization mass spectrometry (LDPI-MS). Results show detection of the parent ion, various fragments, and extracellular material from biofilms using LDPI-MS with both vacuum and extreme ultraviolet photons. Parent ions were observed for both cases, but extreme ultraviolet photons (16-24 eV) induced more fragmentation than vacuum ultraviolet (8-14 eV) photons.

  4. Low-cost method for producing extreme ultraviolet lithography optics

    DOEpatents

    Folta, James A.; Montcalm, Claude; Taylor, John S.; Spiller, Eberhard A.

    2003-11-21

    Spherical and non-spherical optical elements produced by standard optical figuring and polishing techniques are extremely expensive. Such surfaces can be cheaply produced by diamond turning; however, the roughness in the diamond turned surface prevent their use for EUV lithography. These ripples are smoothed with a coating of polyimide before applying a 60 period Mo/Si multilayer to reflect a wavelength of 134 .ANG. and have obtained peak reflectivities close to 63%. The savings in cost are about a factor of 100.

  5. A study of extreme-ultraviolet emission from cataclysmic variables

    NASA Technical Reports Server (NTRS)

    Polidan, Ronald S.; Mauche, Christopher W.; Wade, Richard A.

    1990-01-01

    Voyager far- and extreme UV spectrophotometric observations of five cataclysmic variables (the dwarf novae SS Cyg and VW Hyi and the novalike variables V3885 Sgr, RW Sex, and IX Vel) are combined with neutral hydrogen column densities derived from the curve-of-growth analysis of interstellar absorption lines in high-resolution IUE spectra to place upper limits on the emitted flux in the 600-700 A EUV band. The Voyager observations of VW Hyi were obtained during both normal and superoutbursts. Detailed accretion disk model calculations show that most of the 600-700 A flux in these systems should originate in the inner accretion disk rather than in the boundary layer. For VW Hyi, the low neutral hydrogen column and excellent Voyager superoutburst data place the observed upper limit to the 600-700 A flux well below the expected EUV flux from the model calculations.

  6. Effects of an extreme desert dust event on the spectral ultraviolet irradiance at El Arenosillo (Spain)

    NASA Astrophysics Data System (ADS)

    Antón, M.; Sorribas, M.; Bennouna, Y.; Vilaplana, J. M.; Cachorro, V. E.; GröBner, J.; Alados-Arboledas, L.

    2012-02-01

    This paper analyzes the effects of an extreme Saharan dust event detected on 6 September 2007 on spectral UV irradiance recorded at El Arenosillo, South Spain. The intensity of the extreme event was detected using the aerosol optical depth (AOD) and Angström exponent series obtained by a Cimel Sun photometer operated at the study site in the framework of the Aerosol Robotic Network (AERONET). This Saharan dust event is characterized by its strong intensity, with a mean daily AOD value at 440 nm of 1.35 ± 0.40 (1.76 ± 0.03 around 13:00 UT). Additionally, a moderate decrease (˜15 Dobson units (1 DU = 2.69 × 1016 molecules cm-2)) in the total ozone column was recorded with a Brewer spectrophotometer during this episode. The spectral UV irradiance was measured from the transportable Quality Assurance of Spectral Ultraviolet Measurements in Europe (QASUME) through the development of a transportable unit reference spectroradiometer. The relative decrease of the UV irradiance at 320 nm on 6 September is about 50% (40%) with respect to days with low (moderate) aerosol loads. This attenuation slightly decreases with increasing wavelength above 315 nm. The relative differences between QASUME measurements and the spectral UV irradiance derived from the Ozone Monitoring Instrument (OMI) were calculated for the desert dust episode. This satellite instrument strongly overestimates the ground-based UV data recorded on 6 September, with differences between 138% at 305 nm and 72% at 380 nm. Finally, the aerosol forcing efficiency (AFE) is evaluated for UV-B (290-315 nm), UV-A (315-400 nm), and erythemal UV (290-400 nm, weighted by the CIE spectrum), showing a notable decrease (in absolute value) with increasing solar zenith angles (SZAs). For instance, the AFE values for the harmful UV-B irradiance change from -0.41 W/m2 per unit of AOD at 440 nm for a SZA of 30° to -0.21 W/m2 per unit of AOD for a SZA of 50°.

  7. Extreme Ultraviolet Variability Experiment (EVE) Multiple EUV Grating Spectrographs (MEGS): Radiometric Calibrations and Results

    NASA Astrophysics Data System (ADS)

    Hock, R. A.; Chamberlin, P. C.; Woods, T. N.; Crotser, D.; Eparvier, F. G.; Woodraska, D. L.; Woods, E. C.

    2012-01-01

    The NASA Solar Dynamics Observatory (SDO), scheduled for launch in early 2010, incorporates a suite of instruments including the Extreme Ultraviolet Variability Experiment (EVE). EVE has multiple instruments including the Multiple Extreme ultraviolet Grating Spectrographs (MEGS) A, B, and P instruments, the Solar Aspect Monitor (SAM), and the Extreme ultraviolet SpectroPhotometer (ESP). The radiometric calibration of EVE, necessary to convert the instrument counts to physical units, was performed at the National Institute of Standards and Technology (NIST) Synchrotron Ultraviolet Radiation Facility (SURF III) located in Gaithersburg, Maryland. This paper presents the results and derived accuracy of this radiometric calibration for the MEGS A, B, P, and SAM instruments, while the calibration of the ESP instrument is addressed by Didkovsky et al. ( Solar Phys., 2010, doi:10.1007/s11207-009-9485-8). In addition, solar measurements that were taken on 14 April 2008, during the NASA 36.240 sounding-rocket flight, are shown for the prototype EVE instruments.

  8. Absolute vacuum ultraviolet photoabsorption cross section studies of atomic and molecular species: Techniques and observational data

    NASA Technical Reports Server (NTRS)

    Judge, D. L.; Wu, C. Y. R.

    1990-01-01

    Absorption of a high energy photon (greater than 6 eV) by an isolated molecule results in the formation of highly excited quasi-discrete or continuum states which evolve through a wide range of direct and indirect photochemical processes. These are: photoionization and autoionization, photodissociation and predissociation, and fluorescence. The ultimate goal is to understand the dynamics of the excitation and decay processes and to quantitatively measure the absolute partial cross sections for all processes which occur in photoabsorption. Typical experimental techniques and the status of observational results of particular interest to solar system observations are presented.

  9. Quantum efficiency of opaque CsI photocathodes with channel electron multiplier arrays in the extreme and far ultraviolet

    NASA Technical Reports Server (NTRS)

    Martin, C.; Bowyer, S.

    1982-01-01

    The arrays are overcoated with a CsI photocathode in the VUV. The measurements are part of the development program for the Extreme Ultraviolet Explorer. Monochromatic light from a hollow cathode discharge source passing through a McPherson grazing incidence monochromator is used to illuminate the CsI photocathode. The beam diameter is kept small (approximately 2 mm) to confine it within the individual thickness strips. A bias grid is used to produce a 50-V/mm electric field to guarantee collection of all photoelectrons emitted by the CEMA (channel electron multiplier array) webbing. The CEMAs are operated with a gain of 2-3 x 10 to the 6th and are moderately saturated. A channeltron secondary transfer standard is used to determine the absolute QE in the EUV, whereas an NBS calibrated windowed photodiode is used to measure the FUV absolute QE. It is noted that the CsI gives a factor of 3 increase in the QE in the EUV and a factor of 50-5000 in the FUV.

  10. Calibration of a microchannel plate based extreme ultraviolet grazing incident spectrometer at the Advanced Light Source.

    PubMed

    Bakeman, M S; van Tilborg, J; Sokollik, T; Baum, D; Ybarrolaza, N; Duarte, R; Toth, C; Leemans, W P

    2010-10-01

    We present the design and calibration of a microchannel plate based extreme ultraviolet spectrometer. Calibration was performed at the Advance Light Source (ALS) at the Lawrence Berkeley National Laboratory (LBNL). This spectrometer will be used to record the single shot spectrum of radiation emitted by the tapered hybrid undulator (THUNDER) undulator installed at the LOASIS GeV-class laser-plasma-accelerator. The spectrometer uses an aberration-corrected concave grating with 1200 lines/mm covering 11-62 nm and a microchannel plate detector with a CsI coated photocathode for increased quantum efficiency in the extreme ultraviolet. A touch screen interface controls the grating angle, aperture size, and placement of the detector in vacuum, allowing for high-resolution measurements over the entire spectral range.

  11. Calibration of a microchannel plate based extreme ultraviolet grazing incident spectrometer at the Advanced Light Source

    SciTech Connect

    Bakeman, M. S.; Tilborg, J. van; Sokollik, T.; Baum, D.; Ybarrolaza, N.; Duarte, R.; Toth, C.; Leemans, W. P.

    2010-10-15

    We present the design and calibration of a microchannel plate based extreme ultraviolet spectrometer. Calibration was performed at the Advance Light Source (ALS) at the Lawrence Berkeley National Laboratory (LBNL). This spectrometer will be used to record the single shot spectrum of radiation emitted by the tapered hybrid undulator (THUNDER) undulator installed at the LOASIS GeV-class laser-plasma-accelerator. The spectrometer uses an aberration-corrected concave grating with 1200 lines/mm covering 11-62 nm and a microchannel plate detector with a CsI coated photocathode for increased quantum efficiency in the extreme ultraviolet. A touch screen interface controls the grating angle, aperture size, and placement of the detector in vacuum, allowing for high-resolution measurements over the entire spectral range.

  12. Investigations on the emission in the extreme ultraviolet of a pseudospark based discharge light source

    NASA Astrophysics Data System (ADS)

    Bergmann, Klaus; Vieker, Jochen; von Wezyk, Alexander

    2016-10-01

    A new concept of a discharge based extreme ultraviolet radiation source is presented. This concept is based on an electrode system that consists of two consecutive pseudospark discharge stages. The first stage is used to create a pinch plasma as emitter in the extreme ultraviolet and soft X-ray range and the second stage is used as a high current switch between the storage capacity and the first stage. First results on the emission characteristics for the working gases nitrogen, krypton, and xenon, with focus on the emission at 2.88 nm, 6-7 nm, and around 13.5 nm, respectively, are disclosed under the aspect of the access to a larger discharge parameter range. It is shown that this increased range opens a path to a higher spectral peak brightness.

  13. Method for plasma formation for extreme ultraviolet lithography-theta pinch

    DOEpatents

    Hassanein, Ahmed; Konkashbaev, Isak; Rice, Bryan

    2007-02-20

    A device and method for generating extremely short-wave ultraviolet electromagnetic wave, utilizing a theta pinch plasma generator to produce electromagnetic radiation in the range of 10 to 20 nm. The device comprises an axially aligned open-ended pinch chamber defining a plasma zone adapted to contain a plasma generating gas within the plasma zone; a means for generating a magnetic field radially outward of the open-ended pinch chamber to produce a discharge plasma from the plasma generating gas, thereby producing a electromagnetic wave in the extreme ultraviolet range; a collecting means in optical communication with the pinch chamber to collect the electromagnetic radiation; and focusing means in optical communication with the collecting means to concentrate the electromagnetic radiation.

  14. High-resolution time-resolved extreme ultraviolet spectroscopy on NSTX.

    PubMed

    Lepson, J K; Beiersdorfer, P; Clementson, J; Bitter, M; Hill, K W; Kaita, R; Skinner, C H; Roquemore, A L; Zimmer, G

    2012-10-01

    We report on upgrades to the flat-field grazing-incidence grating spectrometers X-ray and Extreme Ultraviolet Spectrometer (XEUS) and Long-Wavelength Extreme Ultraviolet Spectrometer (LoWEUS), at the National Spherical Torus Experiment (NSTX) at the Princeton Plasma Physics Laboratory. XEUS employs a variable space grating with an average spacing of 2400 lines/mm and covers the 9-64 Å wavelength band, while LoWEUS has an average spacing of 1200 lines/mm and is positioned to monitor the 90-270 Å wavelength band. Both spectrometers have been upgraded with new cameras that achieve 12.5 ms time resolution. We demonstrate the new time resolution capability by showing the time evolution of iron in the NSTX plasma.

  15. High-resolution extreme-ultraviolet spectroscopy of potassium using anti-Stokes radiation

    NASA Technical Reports Server (NTRS)

    Rothenberg, J. E.; Young, J. F.; Harris, S. E.

    1981-01-01

    The use of a new extreme-ultraviolet radiation source based on spontaneous anti-Stokes scattering for high-resolution absorption spectroscopy of transition originating from the 3p6 shell of potassium is reported. The region from 546.6 to 536.8 A is scanned at a resolution of about 1.2 Kayser. Within this region, four previously unreported lines are observed.

  16. A NOISE ADAPTIVE FUZZY EQUALIZATION METHOD FOR PROCESSING SOLAR EXTREME ULTRAVIOLET IMAGES

    SciTech Connect

    Druckmueller, M.

    2013-08-15

    A new image enhancement tool ideally suited for the visualization of fine structures in extreme ultraviolet images of the corona is presented in this paper. The Noise Adaptive Fuzzy Equalization method is particularly suited for the exceptionally high dynamic range images from the Atmospheric Imaging Assembly instrument on the Solar Dynamics Observatory. This method produces artifact-free images and gives significantly better results than methods based on convolution or Fourier transform which are often used for that purpose.

  17. Extreme Ultraviolet Imaging of Electron Heated Targets in Petawatt Laser Experiments

    SciTech Connect

    Ma, T; MacPhee, A; Key, M; Akli, K; Mackinnon, A; Chen, C; Barbee, T; Freeman, R; King, J; Link, A; Offermann, D; Ovchinnikov, V; Patel, P; Stephens, R; VanWoerkom, L; Zhang, B; Beg, F

    2007-11-29

    The study of the transport of electrons, and the flow of energy into a solid target or dense plasma, is instrumental in the development of fast ignition inertial confinement fusion. An extreme ultraviolet (XUV) imaging diagnostic at 256 eV and 68 eV provides information about heating and energy deposition within petawatt laser-irradiated targets. XUV images of several irradiated solid targets are presented.

  18. Extreme ultraviolet marking system for anti-counterfeiting tags with adjustable security level

    NASA Astrophysics Data System (ADS)

    Di Lazzaro, P.; Bollanti, S.; Flora, F.; Mezi, L.; Murra, D.; Torre, A.; Bonfigli, F.; Montereali, R. M.; Vincenti, M. A.

    2012-01-01

    We present a recently patented apparatus which consists of an extreme ultraviolet radiation source writing invisible patterns on thin tags of alkali halides. The tags patterned using this method are almost impossible to counterfeit, and offer a much better protection against fakes than available anti-counterfeiting techniques. We will discuss if this novel technology is ready for industrial production of anti-counterfeiting tags.

  19. Transmission grating based extreme ultraviolet imaging spectrometer for time and space resolved impurity measurements.

    PubMed

    Kumar, Deepak; Stutman, Dan; Tritz, Kevin; Finkenthal, Michael; Tarrio, Charles; Grantham, Steven

    2010-10-01

    A free standing transmission grating based imaging spectrometer in the extreme ultraviolet range has been developed for the National Spherical Torus Experiment (NSTX). The spectrometer operates in a survey mode covering the approximate spectral range from 30 to 700 Å and has a resolving capability of δλ/λ on the order of 3%. Initial results from space resolved impurity measurements from NSTX are described in this paper.

  20. Bright subcycle extreme ultraviolet bursts from a single dense relativistic electron sheet.

    PubMed

    Ma, W J; Bin, J H; Wang, H Y; Yeung, M; Kreuzer, C; Streeter, M; Foster, P S; Cousens, S; Kiefer, D; Dromey, B; Yan, X Q; Meyer-ter-Vehn, J; Zepf, M; Schreiber, J

    2014-12-05

    Double-foil targets separated by a low density plasma and irradiated by a petawatt-class laser are shown to be a copious source of coherent broadband radiation. Simulations show that a dense sheet of relativistic electrons is formed during the interaction of the laser with the tenuous plasma between the two foils. The coherent motion of the electron sheet as it transits the second foil results in strong broadband emission in the extreme ultraviolet, consistent with our experimental observations.

  1. Observations of Diffuse Extreme-Ultraviolet Emission with the Cosmic Hot Interstellar Plasma Spectrometer (CHIPS)

    NASA Astrophysics Data System (ADS)

    Hurwitz, M.; Sasseen, T. P.; Sirk, M. M.

    2005-04-01

    The Cosmic Hot Interstellar Plasma Spectrometer (CHIPS) was designed to study diffuse emission from hot gas in the local interstellar cavity in the wavelength range 90-265 Å. Between launch in 2003 January and early 2004, the instrument was operated in narrow-slit mode, achieving a peak spectral resolution of about 1.4 Å FWHM. Observations were carried out preferentially at high Galactic latitudes; weighted by observing time, the mean absolute value of the Galactic latitude for all narrow-slit observations combined is about 45°. The total integration time is about 13.2 Ms (74% day, 26% night). In the context of a standard collisional ionization equilibrium plasma model, the CHIPS data set tight constraints on the emission measure at temperatures between 105.55 and 106.4 K. At 106.0 K, the 95% upper limit on the emission measure is about 0.0004 cm-6 pc for solar-abundance plasma with a foreground neutral hydrogen column of 2×1018 cm-2. This constraint, derived primarily from limits on the extreme ultraviolet emission lines of highly ionized iron, is well below the range for the local hot bubble estimated previously from soft X-ray studies. If the pattern of elemental depletion in the hot gas follows that observed in much denser interstellar clouds, the gas-phase abundance of iron, relative to other heavy elements that contribute more to the soft X-ray emission, might be much lower than solar. However, to support the emission measures inferred previously from X-ray data would require depletions much higher than the moderate values reported previously for hot gas. Excluding the He II Lyman lines, which are known to be primarily terrestrial in origin, the brightest feature we find in the integrated spectrum is an Fe IX line at 171.1 Å. The sky-averaged flux of the feature is about 6 photons cm-2 s-1 sr-1, a flux that exceeds the 1 σ shot noise significantly but is comparable to the systematic uncertainty. We find bright 171.1 Å emission (flux greater than 10

  2. Absolute Ultraviolet Absorption Spectrum of a Criegee Intermediate CH2OO.

    PubMed

    Sheps, Leonid

    2013-12-19

    We present the time-resolved UV absorption spectrum of the B̃ ((1)A') ← X̃ ((1)A') electronic transition of formaldehyde oxide, CH2OO, produced by the reaction of CH2I radicals with O2. In contrast to its UV photodissociation action spectrum, the absorption spectrum of formaldehyde oxide extends to longer wavelengths and exhibits resolved vibrational structure on its low-energy side. Chemical kinetics measurements of its reactivity establish the identity of the absorbing species as CH2OO. Separate measurements of the initial CH2I radical concentration allow a determination of the absolute absorption cross section of CH2OO, with the value at the peak of the absorption band, 355 nm, of σabs = (3.6 ± 0.9) × 10(-17) cm(2). The difference between the absorption and action spectra likely arises from excitation to long-lived B̃ ((1)A') vibrational states that relax to lower electronic states by fluorescence or nonradiative processes, rather than by photodissociation.

  3. Extreme-Ultraviolet-Initated High-Order Harmonic Generation: Driving Inner-Valence Electrons Using Below-Threshold-Energy Extreme-Ultraviolet Light.

    PubMed

    Brown, A C; van der Hart, H W

    2016-08-26

    We propose a novel scheme for resolving the contribution of inner- and outer-valence electrons in extreme-ultraviolet (XUV)-initiated high-harmonic generation in neon. By probing the atom with a low-energy (below the 2s ionization threshold) ultrashort XUV pulse, the 2p electron is steered away from the core, while the 2s electron is enabled to describe recollision trajectories. By selectively suppressing the 2p recollision trajectories, we can resolve the contribution of the 2s electron to the high-harmonic spectrum. We apply the classical trajectory model to account for the contribution of the 2s electron, which allows for an intuitive understanding of the process.

  4. Extreme-Ultraviolet-Initated High-Order Harmonic Generation: Driving Inner-Valence Electrons Using Below-Threshold-Energy Extreme-Ultraviolet Light

    NASA Astrophysics Data System (ADS)

    Brown, A. C.; van der Hart, H. W.

    2016-08-01

    We propose a novel scheme for resolving the contribution of inner- and outer-valence electrons in extreme-ultraviolet (XUV)-initiated high-harmonic generation in neon. By probing the atom with a low-energy (below the 2 s ionization threshold) ultrashort XUV pulse, the 2 p electron is steered away from the core, while the 2 s electron is enabled to describe recollision trajectories. By selectively suppressing the 2 p recollision trajectories, we can resolve the contribution of the 2 s electron to the high-harmonic spectrum. We apply the classical trajectory model to account for the contribution of the 2 s electron, which allows for an intuitive understanding of the process.

  5. The extreme ultraviolet imager of solar orbiter: optical design and alignment scheme

    NASA Astrophysics Data System (ADS)

    Halain, J.-P.; Mazzoli, A.; Meining, S.; Rochus, P.; Renotte, E.; Auchère, F.; Schühle, U.; Delmotte, F.; Dumesnil, C.; Philippon, A.; Mercier, R.; Hermans, A.

    2015-09-01

    The Extreme Ultraviolet Imager (EUI) is one of the remote sensing instruments on-board the Solar Orbiter mission. It will provide dual-band full-Sun images of the solar corona in the extreme ultraviolet (17.1 nm and 30.4 nm), and high resolution images of the solar disk in both extreme ultraviolet (17.1 nm) and vacuum ultraviolet (Lyman-alpha 121.6 nm). The EUI optical design takes heritage of previous similar instruments. The Full Sun Imager (FSI) channel is a single mirror Herschel design telescope. The two High Resolution Imager (HRI) channels are based on a two-mirror optical refractive scheme, one Ritchey-Chretien and one Gregory optical design for the EUV and the Lyman-alpha channels, respectively. The spectral performances of the EUI channels are obtained thanks to dedicated mirror multilayer coatings and specific band-pass filters. The FSI channel uses a dual-band mirror coating combined with aluminum and zirconium band-pass filters. The HRI channels use optimized band-pass selection mirror coatings combined with aluminum band-pass filters and narrow band interference filters for Lyman-alpha. The optical performances result from accurate mirror manufacturing tolerances and from a two-step alignment procedure. The primary mirrors are first co-aligned. The HRI secondary mirrors and focal planes positions are then adjusted to have an optimum interferometric cavity in each of these two channels. For that purpose a dedicated alignment test setup has been prepared, composed of a dummy focal plane assembly representing the detector position. Before the alignment on the flight optical bench, the overall alignment method has been validated on the Structural and Thermal Model, on a dummy bench using flight spare optics, then on the Qualification Model to be used for the system verification test and qualifications.

  6. Multi-spectral solar telescope array IV; The soft x-ray and extreme ultraviolet filters

    SciTech Connect

    Lindblom, J.F.; O'Neal, R.H.; Walker, A.B.C. Jr. ); Powell, F.R. ); Barbee, T.W. Jr. ); Hoover, R.B. ); Powell, S.F. )

    1991-08-01

    The multilayer mirrors used in the normal-incidence optical systems of the Multi-Spectral Solar Telescope Array (MSSTA) are efficient reflectors for soft x-ray/extreme ultraviolet (EUV) radiation at wavelengths that satisfy the Bragg condition, thus allowing a narrow band of the soft x-ray/EUV spectrum to be isolated. However, these same mirrors are also excellent reflectors in the visible, ultraviolet, and far-ultraviolet (FUV) part of the spectrum, where normal incidence reflectivities can exceed 50%. Furthermore, the sun emits far more radiation in the ultraviolet and visible part of the spectrum than it does in the soft x-ray/EUV. For this reason, thin foil filters are employed to eliminate the unwanted longer wavelength solar emission. The MSSTA instrument uses various combinations of thin foil filters composed of aluminum carbon, tellurium, potassium bromide, beryllium, molybdenum, rhodium, and phthalocyanine to achieve the desired radiation rejection characteristics. In this paper, the authors discuss issues concerning the design, manufacture, and predicted performance of MSSTA filters.

  7. Extreme-Ultraviolet Spectroscopy of Nearby B-Stars: Testing Models of Cosmic Reionization

    NASA Astrophysics Data System (ADS)

    Green, James

    This is a four-year sounding rocket investigation focusing on the extreme-ultraviolet (EUV; 500 – 1150 Å) spectrophotometry of nearby B-stars. Our observations will not only provide powerful constraints on stellar atmosphere models, but also provide key insights towards understanding the reionization of the early universe. The critical region from 700 – 900 Å, where the ionization cross section for neutral hydrogen is at its greatest, has never been observed for any B stars , nor is there any planned instrumentation to cover this waveband. Therefore, a sub-orbital mission is the ideal program to accomplish this science. We will develop a sounding rocket payload called DEUCE – the Dual-channel Extreme Ultraviolet Continuum Experiment. The proposed program addresses NASA’s strategic goals by: A) making unique observations relevant to the physics of re-ionization; B)demonstrating the space worthiness of a new class of ultraviolet detectors, and C)training the next generation of NASA space-mission scientists and PIs

  8. The intrinsic extreme ultraviolet fluxes of F5 V to M5 V stars

    SciTech Connect

    Linsky, Jeffrey L.; Fontenla, Juan; France, Kevin E-mail: jfontenla@nwra.com

    2014-01-01

    Extreme ultraviolet (EUV) radiations (10-117 nm) from host stars play important roles in the ionization, heating, and mass loss from exoplanet atmospheres. Together with the host star's Lyα and far-UV (117-170 nm) radiation, EUV radiation photodissociates important molecules, thereby changing the chemistry in exoplanet atmospheres. Since stellar EUV fluxes cannot now be measured and interstellar neutral hydrogen completely obscures stellar radiation between 40 and 91.2 nm, even for the nearest stars, we must estimate the unobservable EUV flux by indirect methods. New non-LTE semiempirical models of the solar chromosphere and corona and solar irradiance measurements show that the ratio of EUV flux in a variety of wavelength bands to the Lyα flux varies slowly with the Lyα flux and thus with the magnetic heating rate. This suggests and we confirm that solar EUV/Lyα flux ratios based on the models and observations are similar to the available 10-40 nm flux ratios observed with the Extreme Ultraviolet Explorer (EUVE) satellite and the 91.2-117 nm flux observed with the Far Ultraviolet Spectroscopic Explorer (FUSE) satellite for F5 V-M5 V stars. We provide formulae for predicting EUV flux ratios based on the EUVE and FUSE stellar data and on the solar models, which are essential input for modeling the atmospheres of exoplanets.

  9. The Intrinsic Extreme Ultraviolet Fluxes of F5 V TO M5 V Stars

    NASA Astrophysics Data System (ADS)

    Linsky, Jeffrey L.; Fontenla, Juan; France, Kevin

    2014-01-01

    Extreme ultraviolet (EUV) radiations (10-117 nm) from host stars play important roles in the ionization, heating, and mass loss from exoplanet atmospheres. Together with the host star's Lyα and far-UV (117-170 nm) radiation, EUV radiation photodissociates important molecules, thereby changing the chemistry in exoplanet atmospheres. Since stellar EUV fluxes cannot now be measured and interstellar neutral hydrogen completely obscures stellar radiation between 40 and 91.2 nm, even for the nearest stars, we must estimate the unobservable EUV flux by indirect methods. New non-LTE semiempirical models of the solar chromosphere and corona and solar irradiance measurements show that the ratio of EUV flux in a variety of wavelength bands to the Lyα flux varies slowly with the Lyα flux and thus with the magnetic heating rate. This suggests and we confirm that solar EUV/Lyα flux ratios based on the models and observations are similar to the available 10-40 nm flux ratios observed with the Extreme Ultraviolet Explorer (EUVE) satellite and the 91.2-117 nm flux observed with the Far Ultraviolet Spectroscopic Explorer (FUSE) satellite for F5 V-M5 V stars. We provide formulae for predicting EUV flux ratios based on the EUVE and FUSE stellar data and on the solar models, which are essential input for modeling the atmospheres of exoplanets.

  10. High-resolution imaging spectrometer for recording absolutely calibrated far ultraviolet spectra from laser-produced plasmas

    SciTech Connect

    Brown, Charles M.; Seely, John F.; Feldman, Uri; Holland, Glenn E.; Weaver, James L.; Obenschain, Steven P.; Kjornrattanawanich, Benjawan; Fielding, Drew

    2008-10-15

    An imaging spectrometer was designed and fabricated for recording far ultraviolet spectra from laser-produced plasmas with wavelengths as short as 155 nm. The spectrometer implements a Cassegrain telescope and two gratings in a tandem Wadsworth optical configuration that provides diffraction limited resolution. Spectral images were recorded from plasmas produced by the irradiation of various target materials by intense KrF laser radiation with 248 nm wavelength. Two pairs of high-resolution gratings can be selected for the coverage of two wavebands, one grating pair with 1800 grooves/mm and covering approximately 155-175 nm and another grating pair with 1200 grooves/mm covering 230-260 nm. The latter waveband includes the 248 nm KrF laser wavelength, and the former waveband includes the wavelength of the two-plasmon decay instability at (2/3) the KrF laser wavelength (165 nm). The detection media consist of a complementary metal oxide semiconductor imager, photostimulable phosphor image plates, and a linear array of 1 mm{sup 2} square silicon photodiodes with 0.4 ns rise time. The telescope mirrors, spectrometer gratings, and 1 mm{sup 2} photodiode were calibrated using synchrotron radiation, and this enables the measurement of the absolute emission from the laser-produced plasmas with temporal, spatial, and spectral resolutions. The spectrometer is capable of measuring absolute spectral emissions at 165 nm wavelength as small as 5x10{sup -7} J/nm from a plasma source area of 0.37 mm{sup 2} and with 0.4 ns time resolution.

  11. Development of ellipsoidal focusing mirror for soft x-ray and extreme ultraviolet light

    NASA Astrophysics Data System (ADS)

    Mimura, Hidekazu; Takei, Yoshinori; Saito, Takahiro; Kume, Takehiro; Motoyama, Hiroto; Egawa, Satoru; Takeo, Yoko; Higashi, Takahiro

    2015-08-01

    Mirrors are key devices for creating various systems in optics. Focusing X-ray and extreme ultraviolet (EUV) light requires mirror surfaces with an extremely high accuracy. The figure of an ellipsoidal mirror is obtained by rotating an elliptical profile, and using such a mirror, soft X-ray and EUV light can be focused to dimensions on the order of nanometers without chromatic aberration. Although the theoretical performance of ellipsoidal mirrors is extremely high, the fabrication of an ideal ellipsoidal mirror remains problematic. Based on this background, we have been working to develop a fabrication system for ellipsoidal mirrors. In this proceeding, we briefly introduce the fabrication process and the soft X-ray focusing performance of the ellipsoidal mirror fabricated using the proposed process.

  12. Multistep Ionization of Argon Clusters in Intense Femtosecond Extreme Ultraviolet Pulses

    SciTech Connect

    Bostedt, C.; Thomas, H.; Hoener, M.; Eremina, E.; Fennel, T.; Meiwes-Broer, K.-H.; Wabnitz, H.; Kuhlmann, M.; Ploenjes, E.; Tiedtke, K.; Treusch, R.; Feldhaus, J.; Castro, A. R. B. de; Moeller, T.

    2008-04-04

    The interaction of intense extreme ultraviolet femtosecond laser pulses ({lambda}=32.8 nm) from the FLASH free electron laser (FEL) with clusters has been investigated by means of photoelectron spectroscopy and modeled by Monte Carlo simulations. For laser intensities up to 5x10{sup 13} W/cm{sup 2}, we find that the cluster ionization process is a sequence of direct electron emission events in a developing Coulomb field. A nanoplasma is formed only at the highest investigated power densities where ionization is frustrated due to the deep cluster potential. In contrast with earlier studies in the IR and vacuum ultraviolet spectral regime, we find no evidence for electron emission from plasma heating processes.

  13. Compact multi-bounce projection system for extreme ultraviolet projection lithography

    DOEpatents

    Hudyma, Russell M.

    2002-01-01

    An optical system compatible with short wavelength (extreme ultraviolet) radiation comprising four optical elements providing five reflective surfaces for projecting a mask image onto a substrate. The five optical surfaces are characterized in order from object to image as concave, convex, concave, convex and concave mirrors. The second and fourth reflective surfaces are part of the same optical element. The optical system is particularly suited for ring field step and scan lithography methods. The invention uses aspheric mirrors to minimize static distortion and balance the static distortion across the ring field width, which effectively minimizes dynamic distortion.

  14. Development of a Wafer Positioning System for the Sandia Extreme Ultraviolet Lithography Tool

    NASA Technical Reports Server (NTRS)

    Wronosky, John B.; Smith, Tony G.; Darnold, Joel R.

    1996-01-01

    A wafer positioning system was recently developed by Sandia National Laboratories for an Extreme Ultraviolet Lithography (EUVL) tool. The system, which utilizes a magnetically levitated fine stage to provide ultra-precise positioning in all six degrees of freedom, incorporates technological improvements resulting from four years of prototype development. This paper describes the design, implementation, and functional capability of the system. Specifics regarding control system electronics, including software and control algorithm structure, as well as performance design goals and test results are presented. Potential system enhancements, some of which are in process, are also discussed.

  15. Design, fabrication and performance of two grazing incidence telescopes for celestial extreme ultraviolet astronomy

    NASA Technical Reports Server (NTRS)

    Lampton, M.; Cash, W.; Malina, R. F.; Bowyer, S.

    1977-01-01

    The design and performance of grazing incidence telescopes for celestial extreme ultraviolet (EUV) astronomy are described. The telescopes basically consist of a star tracker, collimator, grazing incidence mirror, vacuum box lid, vacuum housing, filters, a ranicon detector, an electronics box, and an aspect camera. For the survey mirror a Wolter-Schwarzschild type II configuration was selected. Diamond-turning was used for mirror fabrication, a technique which machines surfaces to the order of 10 microns over the required dimensions. The design of the EUV spectrometer is discussed with particular reference to the optics for a primarily spectroscopic application and the fabrication of the f/10 optics.

  16. Attosecond extreme ultraviolet generation in cluster by using spatially inhomogeneous field

    SciTech Connect

    Feng, Liqiang; Liu, Hang

    2015-01-15

    A promising method to generate the attosecond extreme ultraviolet (XUV) sources has been theoretically investigated emerging from the two-dimensional Ar{sup +} cluster driven by the spatially inhomogeneous field. The results show that with the introduction of the Ar{sup +} cluster model, not only the harmonic cutoffs are enhanced, but also the harmonic yields are reinforced. Furthermore, by properly moderating the inhomogeneity as well as the laser parameters of the inhomogeneous field, the harmonic cutoff can be further extended. As a result, three almost linearly polarized XUV pulses with durations of 40 as, 42 as, and 45 as can be obtained.

  17. Properites of ultrathin films appropriate for optics capping layers in extreme ultraviolet lithography (EUVL)

    SciTech Connect

    Bajt, S; Edwards, N V; Madey, T E

    2007-06-25

    The contamination of optical surfaces by irradiation shortens optics lifetime and is one of the main concerns for optics used in conjunction with intense light sources, such as high power lasers, 3rd and 4th generation synchrotron sources or plasma sources used in extreme ultraviolet lithography (EUVL) tools. This paper focuses on properties and surface chemistry of different materials, which as thin layers, could be used as capping layers to protect and extend EUVL optics lifetime. The most promising candidates include single element materials such as ruthenium and rhodium, and oxides such as TiO{sub 2} and ZrO{sub 2}.

  18. Note: Enhancement of the extreme ultraviolet emission from a potassium plasma by dual laser irradiation

    SciTech Connect

    Higashiguchi, Takeshi Yamaguchi, Mami; Otsuka, Takamitsu; Nagata, Takeshi; Ohashi, Hayato; Li, Bowen; D’Arcy, Rebekah; Dunne, Padraig; O’Sullivan, Gerry

    2014-09-15

    Emission spectra from multiply charged potassium ions ranging from K{sup 3+} to K{sup 5+} have been obtained in the extreme ultraviolet (EUV) spectral region. A strong emission feature peaking around 38 nm, corresponding to a photon energy of 32.6 eV, is the dominant spectral feature at time-averaged electron temperatures in the range of 8−12 eV. The variation of this emission with laser intensity and the effects of pre-pulses on the relative conversion efficiency (CE) have been explored experimentally and indicate that an enhancement of about 30% in EUV CE is readily attainable.

  19. Structural Characterization of a Mo/Ru/Si Extreme Ultraviolet (EUV) Reflector by Optical Modeling

    NASA Astrophysics Data System (ADS)

    Kang, In-Yong; Kim, Tae Geun; Lee, Seung Yoon; Ahn, Jinho; Chung, Yong-Chae

    2004-06-01

    The performance of a multilayer extreme ultraviolet (EUV) reflector has a direct bearing on process throughput and the cost of new technology. Using measured data from an experimentally manufactured reflector, we intend, in this work, to show that the reflectivity of the Bragg reflector can be characterized by using structural parameters such as the d-spacing, density, thicknesses of the interdiffusion layers and oxidation layer. This quantitative analysis of the reflectivity derived from the structural parameters can be utilized to optimize the optical properties of the existing Mo/Ru/Si system and to provide fundamental insights into the science involved in a Bragg EUV reflector.

  20. Evolution of laser-produced Sn extreme ultraviolet source diameter for high-brightness source

    SciTech Connect

    Roy, Amitava E-mail: aroy@barc.gov.in; Arai, Goki; Hara, Hiroyuki; Higashiguchi, Takeshi; Ohashi, Hayato; Sunahara, Atsushi; Li, Bowen; Dunne, Padraig; O'Sullivan, Gerry; Miura, Taisuke; Mocek, Tomas; Endo, Akira

    2014-08-18

    We have investigated the effect of irradiation of solid Sn targets with laser pulses of sub-ns duration and sub-mJ energy on the diameter of the extreme ultraviolet (EUV) emitting region and source conversion efficiency. It was found that an in-band EUV source diameter as low as 18 μm was produced due to the short scale length of a plasma produced by a sub-ns laser. Most of the EUV emission occurs in a narrow region with a plasma density close to the critical density value. Such EUV sources are suitable for high brightness and high repetition rate metrology applications.

  1. Extreme ultraviolet source at 6.7 nm based on a low-density plasma

    SciTech Connect

    Higashiguchi, Takeshi; Yugami, Noboru; Otsuka, Takamitsu; Jiang, Weihua; Endo, Akira; Li Bowen; Kilbane, Deirdre; Dunne, Padraig; O'Sullivan, Gerry

    2011-11-07

    We demonstrate an efficient extreme ultraviolet (EUV) source for operation at {lambda} = 6.7 nm by optimizing the optical thickness of gadolinium (Gd) plasmas. Using low initial density Gd targets and dual laser pulse irradiation, we observed a maximum EUV conversion efficiency (CE) of 0.54% for 0.6% bandwidth (BW) (1.8% for 2% BW), which is 1.6 times larger than the 0.33% (0.6% BW) CE produced from a solid density target. Enhancement of the EUV CE by use of a low-density plasma is attributed to the reduction of self-absorption effects.

  2. Rare-earth plasma extreme ultraviolet sources at 6.5-6.7 nm

    SciTech Connect

    Otsuka, Takamitsu; Higashiguchi, Takeshi; Yugami, Noboru; Yatagai, Toyohiko; Kilbane, Deirdre; White, John; Dunne, Padraig; O'Sullivan, Gerry; Jiang, Weihua; Endo, Akira

    2010-09-13

    We have demonstrated a laser-produced plasma extreme ultraviolet source operating in the 6.5-6.7 nm region based on rare-earth targets of Gd and Tb coupled with a Mo/B{sub 4}C multilayer mirror. Multiply charged ions produce strong resonance emission lines, which combine to yield an intense unresolved transition array. The spectra of these resonant lines around 6.7 nm (in-band: 6.7 nm {+-}1%) suggest that the in-band emission increases with increased plasma volume by suppressing the plasma hydrodynamic expansion loss at an electron temperature of about 50 eV, resulting in maximized emission.

  3. Multilayer mirror with enhanced spectral selectivity for the next generation extreme ultraviolet lithography

    SciTech Connect

    Medvedev, V. V. Kruijs, R. W. E. van de; Yakshin, A. E.; Novikova, N. N.; Krivtsun, V. M.; Louis, E.; Bijkerk, F.; Yakunin, A. M.

    2013-11-25

    We have demonstrated a hybrid extreme ultraviolet (EUV) multilayer mirror for 6.x nm radiation that provides selective suppression for infrared (IR) radiation. The mirror consists of an IR-transparent LaN∕B multilayer stack which is used as EUV-reflective coating and antireflective (AR) coating to suppress IR. The AR coating can be optimized to suppress CO{sub 2} laser radiation at the wavelength of 10.6 μm, which is of interest for application in next-generation EUV lithography systems.

  4. High resolution extreme ultraviolet spectrometer for an electron beam ion trap

    SciTech Connect

    Ohashi, Hayato; Yatsurugi, Junji; Nakamura, Nobuyuki; Sakaue, Hiroyuki A.

    2011-08-15

    An extreme ultraviolet spectrometer has been developed for spectroscopic studies of highly charged ions with an electron beam ion trap. It has a slit-less configuration with a spherical varied-line-spacing grating that provides a flat focal plane for grazing incidence light. Alternative use of two different gratings enables us to cover the wavelength range 1-25 nm. Test observations with the Tokyo electron beam ion trap demonstrate the high performance of the present spectrometer such as a resolving power of above 1000.

  5. Surface evaluation of the grazing incidence mirrors for the Extreme Ultraviolet Explorer

    NASA Technical Reports Server (NTRS)

    Green, James; Finley, David S.; Bowyer, Stuart; Malina, Roger F.

    1987-01-01

    The EUV scattering from the Wolter-Schwarzschild type I short wavelength scanner mirror aboard the Extreme Ultraviolet Explorer is measured, and the results are used to evaluate the surface microroughness of the mirror. It is found that the most likely values for the mirror surface are sigma = 20 A, and rho = 40 microns. These results are consistent with previous estimates, but with a higher degree of certainty. The full-scale simulation presented here allows over 99 percent of the light distribution to be reasonably modeled.

  6. Oxidation resistance and microstructure of Ru-capped extreme ultraviolet lithography multilayers

    SciTech Connect

    Bajt, S; Dai, Z; Nelson, E J; Wall, M A; Alameda, J B; Nguyen, N; Baker, S L; Robinson, J C; Taylor, J S; Aquila, A; Edwards, N V

    2005-06-15

    The oxidation resistance of protective capping layers for extreme ultraviolet lithography (EUVL) multilayers depends on their microstructure. Differently prepared Ru-capping layers, deposited on Mo/Si EUVL multilayers, were investigated to establish their baseline structural, optical, and surface properties in as-deposited state. The same capping layer structures were then tested for their thermal stability and oxidation resistance. The best performing Ru-capping layer structure was analyzed in detail with transmission electron microscopy (TEM). As compared to other Ru capping layers preparations studied here it is the only one that shows grains with preferential orientation. This information is essential for modeling and performance optimization of EUVL multilayers.

  7. Single shot extreme ultraviolet laser imaging of nanostructures with wavelength resolution

    SciTech Connect

    Jones, Juanita; Brewer, Courtney A.; Brizuela, Fernando; Wachulak, Przemyslaw; Martz, Dale H.; Chao, Weilun; Anderson, Erik H.; Attwood, David T.; Vinogradov, Alexander V.; Artyukov, Igor A.; Ponomareko, Alexander G.; Kondratenko, Valeriy V.; Marconi, Mario C.; Rocca, Jorge J.; Menoni, Carmen S.

    2008-01-07

    We have demonstrated near-wavelength resolution microscopy in the extreme ultraviolet. Images of 50 nm diameter nanotubes were obtained with a single {approx}1 ns duration pulse from a desk-top size 46.9 nm laser. We measured the modulation transfer function of the microscope for three different numerical aperture zone plate objectives, demonstrating that 54 nm half-period structures can be resolved. The combination of near-wavelength spatial resolution and high temporal resolution opens myriad opportunities in imaging, such as the ability to directly investigate dynamics of nanoscale structures.

  8. Passivating overcoat bilayer for multilayer reflective coatings for extreme ultraviolet lithography

    DOEpatents

    Montcalm, Claude; Stearns, Daniel G.; Vernon, Stephen P.

    1999-01-01

    A passivating overcoat bilayer is used for multilayer reflective coatings for extreme ultraviolet (EUV) or soft x-ray applications to prevent oxidation and corrosion of the multilayer coating, thereby improving the EUV optical performance. The overcoat bilayer comprises a layer of silicon or beryllium underneath at least one top layer of an elemental or a compound material that resists oxidation and corrosion. Materials for the top layer include carbon, palladium, carbides, borides, nitrides, and oxides. The thicknesses of the two layers that make up the overcoat bilayer are optimized to produce the highest reflectance at the wavelength range of operation. Protective overcoat systems comprising three or more layers are also possible.

  9. Heating dynamics and extreme ultraviolet radiation emission of laser-produced Sn plasmas

    SciTech Connect

    Yuspeh, S.; Sequoia, K. L.; Tao, Y.; Tillack, M. S.; Burdt, R. A.; Najmabadi, F.

    2010-06-28

    The impact of 1.064 mum laser absorption depth on the heating and in-band (2% bandwidth) 13.5 nm extreme ultraviolet emissions in Sn plasmas is investigated experimentally and numerically. In-band emission lasting longer than the laser pulse and separation between the laser absorption and in-band emission region are observed. Maximum efficiency is achieved by additional heating of the core of the plasma to allow the optimal temperature to expand to a lower and more optically thin density. This leads to higher temperature plasma that emits less in-band light as compared to CO{sub 2} produced plasma sources for the same application.

  10. Grazing incidence metal optics for the Berkeley Extreme Ultraviolet Explorer satellite - A progress report

    NASA Technical Reports Server (NTRS)

    Finley, D.; Malina, R. F.; Bowyer, S.

    1985-01-01

    The four flight Wolter-Schwarzschild mirrors currently under fabrication for the Extreme Ultraviolet Explorer (EUVE) satellite are described. The principal figuring operation of these grazing incidence metal mirrors (gold over nickel on an aluminum substrate) is carried out by diamond turning at the Lawrence Livermore National Laboratories. Turning has been accomplished and optical testing results analyzed for three of the mirrors. As-turned values of 1.7 arc sec full width at half maximum (FWHM) and half energy width (HEW) of 5 arc seconds in the visible have been achieved. These results illustrate the great potential of precision fabrication technology for the production of large grazing incidence optics.

  11. Exploring the temporally resolved electron density evolution in extreme ultra-violet induced plasmas

    NASA Astrophysics Data System (ADS)

    van der Horst, R. M.; Beckers, J.; Nijdam, S.; Kroesen, G. M. W.

    2014-07-01

    We measured the electron density in an extreme ultra-violet (EUV) induced plasma. This is achieved in a low-pressure argon plasma by using a method called microwave cavity resonance spectroscopy. The measured electron density just after the EUV pulse is 2.6 × 1016 m-3. This is in good agreement with a theoretical prediction from photo-ionization, which yields a density of 4.5 × 1016 m-3. After the EUV pulse the density slightly increases due to electron impact ionization. The plasma (i.e. electron density) decays in tens of microseconds.

  12. Real-time observations of extreme-ultraviolet aerial images by fluorescence microimaging

    SciTech Connect

    La Fontaine, B. ); White, D.L. ); Wood, O.R. II ); MacDowell, A.A.; Tan, Z. ); Taylor, G.N. ); Tennant, D.M. ); Hulbert, S.L. )

    1994-11-01

    A new technique, fluorescence microimaging (FMI), using single-crystal phosphors was used to look directly at aerial images produced by an extreme-ultraviolet (EUV) camera operating at a wavelength of 139 A. The achieved spatial resolution was estimated to be [similar to]0.2 [mu]m. A comparison of this technique with the usual resist-exposure scanning electron microscopy inspection technique as a means of focusing a 20[times]EUV Schwarzschild camera was performed. FMI could in principle be improved to view fluorescent images with features as small as 0.07 [mu]m, in real time.

  13. Final Report: Spectral Analysis of L-shell Data in the Extreme Ultraviolet from Tokamak Plasmas

    SciTech Connect

    Lepson, J.; Jernigan, J. Garrett; Beiersdorfer, P.

    2016-02-05

    We performed detailed analyses of extreme ultraviolet spectra taken by Lawrence Livermore National Laboratory on the National Spherical Torus Experiment at Princeton Plasma Physics Laboratory and on the Alcator CKmod tokamak at the M.I.T. Plasma Science and Fusion Center. We focused on the emission of iron, carbon, and other elements in several spectral band pass regions covered by the Atmospheric Imaging Assembly on the Solar Dynamics Observatory. We documented emission lines of carbon not found in currently used solar databases and demonstrated that this emission was due to charge exchange.

  14. Invited Article: Progress in coherent lithography using table-top extreme ultraviolet lasers.

    PubMed

    Li, W; Urbanski, L; Marconi, M C

    2015-12-01

    Compact (table top) lasers emitting at wavelengths below 50 nm had expanded the spectrum of applications in the extreme ultraviolet (EUV). Among them, the high-flux, highly coherent laser sources enabled lithographic approaches with distinctive characteristics. In this review, we will describe the implementation of a compact EUV lithography system capable of printing features with sub-50 nm resolution using Talbot imaging. This compact system is capable of producing consistent defect-free samples in a reliable and effective manner. Examples of different patterns and structures fabricated with this method will be presented.

  15. Top surface imaging process and materials development for 193 nm and extreme ultraviolet lithography

    SciTech Connect

    Rao, V.; Hutchinson, J.; Holl, S.; Langston, J.; Henderson, C.; Wheeler, D.R.; Cardinale, G.; OConnell, D.; Goldsmith, J.; Bohland, J.; Taylor, G.; Sinta, R.

    1998-11-01

    The maturity and acceptance of top surface imaging (TSI) technology have been hampered by several factors including inadequate resist sensitivity and line edge roughness. We have found that the use of a chemically amplified resist can improve the sensitivity in these systems by 1.5{endash} 2{times} without compromising the line edge roughness. In addition, we have shown improved line edge roughness by increasing the molecular weight of the polymeric resin in the resist. Using these materials approaches, we have been able to show excellent resolution images with the TSI process for both 193 nm and extreme ultraviolet (13.4 nm) patterning. {copyright} {ital 1998 American Vacuum Society.}

  16. Extreme ultraviolet (EUV) degradation of poly(olefin sulfone)s: Towards applications as EUV photoresists

    NASA Astrophysics Data System (ADS)

    Lawrie, Kirsten; Blakey, Idriss; Blinco, James; Gronheid, Roel; Jack, Kevin; Pollentier, Ivan; Leeson, Michael J.; Younkin, Todd R.; Whittaker, Andrew K.

    2011-02-01

    Poly(olefin sulfone)s, formed by the reaction of sulfur dioxide (SO 2) and an olefin, are known to be highly susceptible to degradation by radiation and thus have been identified as candidate materials for chain scission-based extreme ultraviolet lithography (EUVL) resist materials. In order to investigate this further, the synthesis and characterisation of two poly(olefin sulfone)s namely poly(1-pentene sulfone) (PPS) and poly(2-methyl-1-pentene sulfone) (PMPS), was achieved and the two materials were evaluated for possible chain scission EUVL resist applications. It was found that both materials possess high sensitivities to EUV photons; however; the rates of outgassing were extremely high. The only observed degradation products were found to be SO 2 and the respective olefin suggesting that depolymerisation takes place under irradiation in a vacuum environment. In addition to depolymerisation, a concurrent conversion of SO 2 moieties to a sulfide phase was observed using XPS.

  17. EIT: Solar corona synoptic observations from SOHO with an Extreme-ultraviolet Imaging Telescope

    NASA Technical Reports Server (NTRS)

    Delaboudiniere, J. P.; Gabriel, A. H.; Artzner, G. E.; Michels, D. J.; Dere, K. P.; Howard, R. A.; Catura, R.; Stern, R.; Lemen, J.; Neupert, W.

    1988-01-01

    The Extreme-ultraviolet Imaging Telescope (EIT) of SOHO (solar and heliospheric observatory) will provide full disk images in emission lines formed at temperatures that map solar structures ranging from the chromospheric network to the hot magnetically confined plasma in the corona. Images in four narrow bandpasses will be obtained using normal incidence multilayered optics deposited on quadrants of a Ritchey-Chretien telescope. The EIT is capable of providing a uniform one arc second resolution over its entire 50 by 50 arc min field of view. Data from the EIT will be extremely valuable for identifying and interpreting the spatial and temperature fine structures of the solar atmosphere. Temporal analysis will provide information on the stability of these structures and identify dynamical processes. EIT images, issued daily, will provide the global corona context for aid in unifying the investigations and in forming the observing plans for SOHO coronal instruments.

  18. Detection of rotational modulation in the coronal extreme-ultraviolet emission from V711 Tauri?

    NASA Technical Reports Server (NTRS)

    Drake, Jeremy J.; Brown, Alex; Patterer, Robert J.; Vedder, Peter W.; Bowyer, Stuart; Guinan, Edward F.

    1994-01-01

    The RS CVn binary V711 Tauri was observed by the Extreme Ultraviolet Explorer satellite (EUVE) twice during the latter half of 1992, for periods lasting several days. Light curves for the waveband 60-180 A derived from the all-sky survey scanning in August and from a pointed calibration observation made in October both exhibit a modulation of about 40%. The modulation in both data sets is very similar, with minimum flux occurring near orbital phase phi = 0.5. Analysis using a two-temperature optically thin plasma emission model reveals that most of the detected extreme ultraviolet (EUV) flux emanates from hot (approximately 10(exp 7) K) coronal plasma. The modulation is probably mostly due to either flare-like activity or to rotational occultation of a long-lived, compact, and especially bright coronal structure on the more active star of the system. The phased data support the latter hypothesis. This coronal structure is then likely to be associated with the presistent spot patterns seen on V711 Tau when using Doppler and photometric surface imaging techniques. Comparison with contemporaneous Stroemgren b-band photometry indicates that the optical minimum light leads the EUV maximum light by 90 deg in phase.

  19. Emission Lines of Fe XI - XIII in the Extreme Ultraviolet Region

    NASA Astrophysics Data System (ADS)

    Lepson, Jaan; Beiersdorfer, Peter; Liedahl, Duane; Desai, Priya; Brickhouse, Nancy; Dupree, Andrea; Kahn, Steven

    2009-05-01

    Iron is one of the most abundant heavy elements in extreme ultraviolet spectra of astrophysical and laboratory plasmas, and its various ions radiate profusely in the extreme ultraviolet (EUV) wavelength band. Iron emission in the EUV provides important d iagnostic tools for such properties as plasma temperature and density, and perhaps even magnetic field strength. Despite its importance to astrophysics and magnetic fusion, knowledge of the EUV spectrum of iron is incomplete. Identification of iron emis sion lines is hampered by the paucity of accurate laboratory measurements and the uncertainty of even the best atomic models. As part of a project to measure and compile emission line data in the EUV, we present here spectra and lines of Fe XI - XIII recorded on the Livermore EBIT-II electron beam ion trap in the 50 - 120 åregion. We measured line positions to 0.02 åand relative intensities with an accuracy of one part in twenty. Many new lines are identified and added to the available databa ses. Part of this work was performed under the auspices of the U S Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 and was supported by NASA's Astronomy and Physics Research and Analysis Program under Con t ract NNH07AF811.

  20. Optimizing laser produced plasmas for efficient extreme ultraviolet and soft X-ray light sources

    SciTech Connect

    Sizyuk, Tatyana; Hassanein, Ahmed

    2014-08-15

    Photon sources produced by laser beams with moderate laser intensities, up to 10{sup 14 }W/cm{sup 2}, are being developed for many industrial applications. The performance requirements for high volume manufacture devices necessitate extensive experimental research supported by theoretical plasma analysis and modeling predictions. We simulated laser produced plasma sources currently being developed for several applications such as extreme ultraviolet lithography using 13.5% ± 1% nm bandwidth, possibly beyond extreme ultraviolet lithography using 6.× nm wavelengths, and water-window microscopy utilizing 2.48 nm (La-α) and 2.88 nm (He-α) emission. We comprehensively modeled plasma evolution from solid/liquid tin, gadolinium, and nitrogen targets as three promising materials for the above described sources, respectively. Results of our analysis for plasma characteristics during the entire course of plasma evolution showed the dependence of source conversion efficiency (CE), i.e., laser energy to photons at the desired wavelength, on plasma electron density gradient. Our results showed that utilizing laser intensities which produce hotter plasma than the optimum emission temperatures allows increasing CE for all considered sources that, however, restricted by the reabsorption processes around the main emission region and this restriction is especially actual for the 6.× nm sources.

  1. Instrumentation on the RAIDS experiment 2: Extreme ultraviolet spectrometer, photometer, and near IR spectrometer

    NASA Astrophysics Data System (ADS)

    Christensen, A. B.; Kayser, D. C.; Pranke, J. B.; Chakrabarti, Supriya; McCoy, R. P.

    1994-02-01

    The RAIDS experiment consists of eight instruments spanning the wavelength range from the extreme ultraviolet (55 nm) to the near infrared (800 nm) oriented to view the Earth's limb from the NOAA-J spacecraft to be launched into a circular orbit in 1993. Through measurements of the natural optical emissions and scattered sunlight originating in the upper atmosphere including the mesosphere and thermosphere, state variables such as temperature, composition, density and ion concentration of this region will be inferred. This report describes the subset of instruments fabricated or otherwise provided by the Space and Environment Technology Center (formerly Space Sciences Laboratory) at The Aerospace Corp. The companion to this report describes the instruments from the Naval Research Laboratory. The Extreme Ultraviolet Spectrograph (EUVS), the three fixed filter photometers OI (630), OI (777), and Na (589), and the near infrared spectrometer (NIR) will be described. These are all mounted on a mechanical scan platform that scans the limb from approximately 75 to 750 km in the orbital plane of the satellite every 90 seconds.

  2. Spectral photometry of extreme helium stars: Ultraviolet fluxes and effective temperature

    NASA Technical Reports Server (NTRS)

    Drilling, J. S.; Schoenberner, D.; Heber, U.; Lynas-Gray, A. E.

    1982-01-01

    Ultraviolet flux distributions are presented for the extremely helium rich stars BD +10 deg 2179, HD 124448, LSS 3378, BD -9 deg 4395, LSE 78, HD 160641, LSIV -1 deg 2, BD 1 deg 3438, HD 168476, MV Sgr, LS IV-14 deg 109 (CD -35 deg 11760), LSII +33 deg 5 and BD +1 deg 4381 (LSIV +2 deg 13) obtained with the International Ultraviolet Explorer (IUE). Broad band photometry and a newly computed grid of line blanketed model atmospheres were used to determine accurate angular diameters and total stellar fluxes. The resultant effective temperatures are in most cases in satisfactory agreement with those based on broad band photometry and/or high resolution spectroscopy in the visible. For two objects, LSII +33 deg 5 and LSE 78, disagreement was found between the IUE observations and broadband photometry: the colors predict temperatures around 20,000 K, whereas the UV spectra indicate much lower photospheric temperatures of 14,000 to 15,000 K. The new temperature scale for extreme helium stars extends to lower effective temperatures than that of Heber and Schoenberner (1981) and covers the range from 8,500 K to 32,000 K.

  3. Large-scale Extreme-Ultraviolet Disturbances Associated with a Limb Coronal Mass Ejection

    NASA Astrophysics Data System (ADS)

    Dai, Y.; Auchère, F.; Vial, J.-C.; Tang, Y. H.; Zong, W. G.

    2010-01-01

    We present composite observations of a coronal mass ejection (CME) and the associated large-scale extreme-ultraviolet (EUV) disturbances on 2007 December 31 by the Extreme-ultraviolet Imager (EUVI) and COR1 coronagraph on board the recent Solar Terrestrial Relations Observatory mission. For this limb event, the EUV disturbances exhibit some typical characteristics of EUV Imaging Telescope waves: (1) in the 195 Å bandpass, diffuse brightenings are observed propagating oppositely away from the flare site with a velocity of ~260 km s-1, leaving dimmings behind; (2) when the brightenings encounter the boundary of a polar coronal hole, they stop there to form a stationary front. Multi-temperature analysis of the propagating EUV disturbances favors a heating process over a density enhancement in the disturbance region. Furthermore, the EUVI-COR1 composite display shows unambiguously that the propagation of the diffuse brightenings coincides with a large lateral expansion of the CME, which consequently results in a double-loop-structured CME leading edge. Based on these observational facts, we suggest that the wave-like EUV disturbances are a result of magnetic reconfiguration related to the CME liftoff rather than true waves in the corona. Reconnections between the expanding CME magnetic field lines and surrounding quiet-Sun magnetic loops account for the propagating diffuse brightenings; dimmings appear behind them as a consequence of volume expansion. X-ray and radio data provide us with complementary evidence.

  4. Detection of rotational modulation in the coronal extreme-ultraviolet emission from V711 Tauri?

    PubMed

    Drake, J J; Brown, A; Patterer, R J; Vedder, P W; Bowyer, S; Guinan, E F

    1994-01-20

    The RS CVn binary V711 Tauri was observed by the Extreme Ultraviolet Explorer satellite (EUVE) twice during the latter half of 1992, for periods lasting several days. Light curves for the waveband 60-180 angstroms derived from the all-sky survey scanning in August and from a pointed calibration observation made in October both exhibit a modulation of about 40%. The modulation in both data sets is very similar, with minimum flux occurring near orbital phase phi=0.5. Analysis using a two-temperature optically thin plasma emission model reveals that most of the detected extreme ultraviolet (EUV) flux emanates from hot (approximately 10(7) K) coronal plasma. The modulation is probably mostly due to either flare-like activity or to rotational occultation of a long-lived, compact, and especially bright coronal structure on the more active star of the system. The phased data support the latter hypothesis. This coronal structure is then likely to be associated with the persistent spot patterns seen on V711 Tau when using Doppler and photometric surface imaging techniques. Comparison with contemporaneous Stromgren b-band photometry indicates that the optical minimum light leads the EUV maximum light by 90 degrees in phase.

  5. Optics and mechanisms for the Extreme-Ultraviolet Imaging Spectrometer on the Solar-B satellite.

    PubMed

    Korendyke, Clarence M; Brown, Charles M; Thomas, Roger J; Keyser, Christian; Davila, Joseph; Hagood, Robert; Hara, Hirohisa; Heidemann, Klaus; James, Adrian M; Lang, James; Mariska, John T; Moser, John; Moye, Robert; Myers, Steven; Probyn, Brian J; Seely, John F; Shea, John; Shepler, Ed; Tandy, Jason

    2006-12-01

    The Extreme-Ultraviolet Imaging Spectrometer (EIS) is the first of a new generation of normal-incidence, two-optical-element spectroscopic instruments developed for space solar extreme-ultraviolet astronomy. The instrument is currently mounted on the Solar-B satellite for a planned launch in late 2006. The instrument observes in two spectral bands, 170-210 A and 250-290 A. The spectrograph geometry and grating prescription were optimized to obtain excellent imaging while still maintaining readily achievable physical and fabrication tolerances. A refined technique using low ruling density surrogate gratings and optical metrology was developed to align the instrument with visible light. Slit rasters of the solar surface are obtained by mechanically tilting the mirror. A slit exchange mechanism allows selection among four slits at the telescope focal plane. Each slit is precisely located at the focal plane. The spectrograph imaging performance was optically characterized in the laboratory. The resolution was measured using the Mg iii and Ne iii lines in the range of 171-200 A. The He ii line at 256 A and Ne iii lines were used in the range of 251-284 A. The measurements demonstrate an equivalent resolution of ~2 arc sec? on the solar surface, in good agreement with the predicted performance. We describe the EIS optics, mechanisms, and measured performance.

  6. [Design of optical system for solar extreme-ultraviolet imaging spectrometer].

    PubMed

    Liu, Zhuang; Gong, Yan

    2012-03-01

    Hyper-spectral imaging observation of the sun in the EUV region is an important method of research for solar's upper transition region, corona and plasma's physical property. Based on the application objective of solar extreme ultraviolet imaging spectrometer (SEUIS), combined with the current states of domestic and foreign extreme ultraviolet imaging spectrometer, a few of parameters for SEUIS design were drew up in the present paper. The advantages and disadvantages of all kinds of optical configurations were discussed,and the configuration of combination of telescope and spectrometer was chosen. The available main components were also described, off-axis parabolic mirror was chosen for telescope, and a high density uniform-line-space toroidal grating for dispersion device. The optical system which satisfies the performance parameters was designed. The design process, detailed parameters and results were presented in the end. The working wavelength of the optics system is 17.0-21.0 nm, the field of view is 1 228" x 1 024", the spatial resolution is 0.8 arc sec x pixel(-1), the spectral resolution is about 0.00198 nm x pixel(-1), and the total length of system is about 2.8 m.

  7. Breaking DNA strands by extreme-ultraviolet laser pulses in vacuum

    NASA Astrophysics Data System (ADS)

    Nováková, Eva; Vyšín, Luděk; Burian, Tomáš; Juha, Libor; Davídková, Marie; Múčka, Viliam; Čuba, Václav; Grisham, Michael E.; Heinbuch, Scott; Rocca, Jorge J.

    2015-04-01

    Ionizing radiation induces a variety of DNA damages including single-strand breaks (SSBs), double-strand breaks (DSBs), abasic sites, modified sugars, and bases. Most theoretical and experimental studies have been focused on DNA strand scissions, in particular production of DNA double-strand breaks. DSBs have been proven to be a key damage at a molecular level responsible for the formation of chromosomal aberrations, leading often to cell death. We have studied the nature of DNA damage induced directly by the pulsed 46.9-nm (26.5 eV) radiation provided by an extreme ultraviolet (XUV) capillary-discharge Ne-like Ar laser (CDL). Doses up to 45 kGy were delivered with a repetition rate of 3 Hz. We studied the dependence of the yield of SSBs and DSBs of a simple model of DNA molecule (pBR322) on the CDL pulse fluence. Agarose gel electrophoresis method was used for determination of both SSB and DSB yields. The action cross sections of the single- and double-strand breaks of pBR322 plasmid DNA in solid state were determined. We observed an increase in the efficiency of strand-break induction in the supercoiled DNA as a function of laser pulse fluence. Results are compared to those acquired at synchrotron radiation facilities and other sources of extreme-ultraviolet and soft x-ray radiation.

  8. Bright high-repetition-rate source of narrowband extreme-ultraviolet harmonics beyond 22 eV

    PubMed Central

    Wang, He; Xu, Yiming; Ulonska, Stefan; Robinson, Joseph S.; Ranitovic, Predrag; Kaindl, Robert A.

    2015-01-01

    Novel table-top sources of extreme-ultraviolet light based on high-harmonic generation yield unique insight into the fundamental properties of molecules, nanomaterials or correlated solids, and enable advanced applications in imaging or metrology. Extending high-harmonic generation to high repetition rates portends great experimental benefits, yet efficient extreme-ultraviolet conversion of correspondingly weak driving pulses is challenging. Here, we demonstrate a highly-efficient source of femtosecond extreme-ultraviolet pulses at 50-kHz repetition rate, utilizing the ultraviolet second-harmonic focused tightly into Kr gas. In this cascaded scheme, a photon flux beyond ≈3 × 1013 s−1 is generated at 22.3 eV, with 5 × 10−5 conversion efficiency that surpasses similar harmonics directly driven by the fundamental by two orders-of-magnitude. The enhancement arises from both wavelength scaling of the atomic dipole and improved spatio-temporal phase matching, confirmed by simulations. Spectral isolation of a single 72-meV-wide harmonic renders this bright, 50-kHz extreme-ultraviolet source a powerful tool for ultrafast photoemission, nanoscale imaging and other applications. PMID:26067922

  9. Bright high-repetition-rate source of narrowband extreme-ultraviolet harmonics beyond 22 eV

    SciTech Connect

    Wang, He; Xu, Yiming; Ulonska, Stefan; Robinson, Joseph S.; Ranitovic, Predrag; Kaindl, Robert A.

    2015-06-11

    Novel table-top sources of extreme-ultraviolet light based on high-harmonic generation yield unique insight into the fundamental properties of molecules, nanomaterials or correlated solids, and enable advanced applications in imaging or metrology. Extending high-harmonic generation to high repetition rates portends great experimental benefits, yet efficient extreme-ultraviolet conversion of correspondingly weak driving pulses is challenging. In this article, we demonstrate a highly-efficient source of femtosecond extreme-ultraviolet pulses at 50-kHz repetition rate, utilizing the ultraviolet second-harmonic focused tightly into Kr gas. In this cascaded scheme, a photon flux beyond ≈3 × 1013 s-1 is generated at 22.3 eV, with 5 × 10-5 conversion efficiency that surpasses similar harmonics directly driven by the fundamental by two orders-of-magnitude. The enhancement arises from both wavelength scaling of the atomic dipole and improved spatio-temporal phase matching, confirmed by simulations. Finally, spectral isolation of a single 72-meV-wide harmonic renders this bright, 50-kHz extreme-ultraviolet source a powerful tool for ultrafast photoemission, nanoscale imaging and other applications.

  10. Bright high-repetition-rate source of narrowband extreme-ultraviolet harmonics beyond 22 eV.

    PubMed

    Wang, He; Xu, Yiming; Ulonska, Stefan; Robinson, Joseph S; Ranitovic, Predrag; Kaindl, Robert A

    2015-06-11

    Novel table-top sources of extreme-ultraviolet light based on high-harmonic generation yield unique insight into the fundamental properties of molecules, nanomaterials or correlated solids, and enable advanced applications in imaging or metrology. Extending high-harmonic generation to high repetition rates portends great experimental benefits, yet efficient extreme-ultraviolet conversion of correspondingly weak driving pulses is challenging. Here, we demonstrate a highly-efficient source of femtosecond extreme-ultraviolet pulses at 50-kHz repetition rate, utilizing the ultraviolet second-harmonic focused tightly into Kr gas. In this cascaded scheme, a photon flux beyond ≈3 × 10(13) s(-1) is generated at 22.3 eV, with 5 × 10(-5) conversion efficiency that surpasses similar harmonics directly driven by the fundamental by two orders-of-magnitude. The enhancement arises from both wavelength scaling of the atomic dipole and improved spatio-temporal phase matching, confirmed by simulations. Spectral isolation of a single 72-meV-wide harmonic renders this bright, 50-kHz extreme-ultraviolet source a powerful tool for ultrafast photoemission, nanoscale imaging and other applications.

  11. Surface modification of polymers for biocompatibility via exposure to extreme ultraviolet radiation.

    PubMed

    Inam Ul Ahad; Bartnik, Andrzej; Fiedorowicz, Henryk; Kostecki, Jerzy; Korczyc, Barbara; Ciach, Tomasz; Brabazon, Dermot

    2014-09-01

    Polymeric biomaterials are being widely used for the treatment of various traumata, diseases and defects in human beings due to ease in their synthesis. As biomaterials have direct interaction with the extracellular environment in the biological world, biocompatibility is a topic of great significance. The introduction or enhancement of biocompatibility in certain polymers is still a challenge to overcome. Polymer biocompatibility can be controlled by surface modification. Various physical and chemical methods (e.g., chemical and plasma treatment, ion implantation, and ultraviolet irradiation etc.) are in use or being developed for the modification of polymer surfaces. However an important limitation in their employment is the alteration of bulk material. Different surface and bulk properties of biomaterials are often desirable for biomedical applications. Because extreme ultraviolet (EUV) radiation penetration is quite limited even in low density mediums, it could be possible to use it for surface modification without influencing the bulk material. This article reviews the degree of biocompatibility of different polymeric biomaterials being currently employed in various biomedical applications, the surface properties required to be modified for biocompatibility control, plasma and laser ablation based surface modification techniques, and research studies indicating possible use of EUV for enhancing biocompatibility.

  12. Photoionization capable, extreme and vacuum ultraviolet emission in developing low temperature plasmas in air

    NASA Astrophysics Data System (ADS)

    Stephens, J.; Fierro, A.; Beeson, S.; Laity, G.; Trienekens, D.; Joshi, R. P.; Dickens, J.; Neuber, A.

    2016-04-01

    Experimental observation of photoionization capable extreme ultraviolet and vacuum ultraviolet emission from nanosecond timescale, developing low temperature plasmas (i.e. streamer discharges) in atmospheric air is presented. Applying short high voltage pulses enabled the observation of the onset of plasma formation exclusively by removing the external excitation before spark development was achieved. Contrary to the common assumption that radiative transitions from the b{{}1}{{\\Pi}u} (Birge-Hopfield I) and b{{}\\prime 1}Σu+ (Birge-Hopfield II) singlet states of N2 are the primary contributors to photoionization events, these results indicate that radiative transitions from the c{{4\\prime}1}Σu+ (Carroll-Yoshino) singlet state of N2 are dominant in developing low temperature plasmas in air. In addition to c{}4\\prime transitions, photoionization capable transitions from atomic and singly ionized atomic oxygen were also observed. The inclusion of c{{4\\prime}1}Σu+ transitions into a statistical photoionization model coupled with a fluid model enabled streamer growth in the simulation of positive streamers.

  13. The extreme ultraviolet spectrum of the kinetically dominated quasar 3C 270.1

    NASA Astrophysics Data System (ADS)

    Punsly, Brian; Marziani, Paola

    2015-10-01

    Only a handful of quasars have been identified as kinetically dominated, their long-term time-averaged jet power, overline{Q}, exceeds the bolometric thermal emission, Lbol, associated with the accretion flow. This Letter presents the first extreme ultraviolet (EUV) spectrum of a kinetically dominated quasar, 3C 270.1. The EUV continuum flux density of 3C 270.1 is very steep, F_{ν } ˜ ν ^{-α _{EUV}}, αEUV = 2.98 ± 0.15. This value is consistent with the correlation of overline{Q}/L_{bol} and αEUV found in previous studies of the EUV continuum of quasars, the EUV deficit of radio loud quasars. Curiously, although ultraviolet broad absorption line (BAL) troughs in quasar spectra are anticorrelated with overline{Q}, 3C 270.1 has been considered a BAL quasar based on an SDSS spectrum. This claim is examined in terms of the EUV spectrum of O VI and the highest resolution C IV spectrum in the archival data and the SDSS spectrum. First, from [O III]4959,5007 (IR) observations and the UV spectral lines, it is concluded that the correct redshift for 3C 270.1 is 1.5266. It is then found that the standard measure of broad absorption, BALnicity = 0, for Mg II 2800, C IV 1549 and O VI 1032 in all epochs.

  14. Extreme ultraviolet emission from laser-induced plasma relevance to neutral gas environment simulation in LEO

    NASA Astrophysics Data System (ADS)

    Tagawa, Masahito; Kimoto, Yugo; Yokota, Kumiko; Ohira, Junki; Watanabe, Daiki; Nishimura, Hiroaki

    The reaction mechanism of atomic oxygen (AO) in low Earth orbit (LEO) with spacecraft materials has been studied by ground-based experiments using laser-detonation hyperthermal beam source, which enables to accelerate the electrically neutral AO up to 8 km/s. However, the beam conditions in the laser-detonation sources could not fully duplicate the AO environment in space. The difference in beam condition including side products leads to the different material responses. The light emission from the laser-induced oxygen plasma may affect the erosion of ultraviolet (UV)-sensitive materials. However, the light emission could also be used as a diagnostic tool to understand the molecular processes in plasma. In this presentation, extreme ultraviolet (EUV) emission from the laser-induced plasma during AO test was evaluated by the flat field EUV spectrometer. Many emission lines between 25-40 nm originated from OII and OIII were observed from the laser-induced oxygen plasma. This result suggested multiple-charged O ions are generated in the laser-induced plasma. Promotion of oxygen dissociation effect by adding Ar in the target gas was explained by the energy transfer processes from Ar to O2 in the plasma. From the viewpoint of reducing the side products in the AO exposure tests, a method to reduce the EUV emission will also be investigated. These results could be used for establishing more accurate ground-based natural gas simulations on the space environmental effect of materials.

  15. Extreme Ultraviolet Fractional Orbital Angular Momentum Beams from High Harmonic Generation.

    PubMed

    Turpin, Alex; Rego, Laura; Picón, Antonio; San Román, Julio; Hernández-García, Carlos

    2017-03-10

    We investigate theoretically the generation of extreme-ultraviolet (EUV) beams carrying fractional orbital angular momentum. To this end, we drive high-order harmonic generation with infrared conical refraction (CR) beams. We show that the high-order harmonic beams emitted in the EUV/soft x-ray regime preserve the characteristic signatures of the driving beam, namely ringlike transverse intensity profile and CR-like polarization distribution. As a result, through orbital and spin angular momentum conservation, harmonic beams are emitted with fractional orbital angular momentum, and they can be synthesized into structured attosecond helical beams -or "structured attosecond light springs"- with rotating linear polarization along the azimuth. Our proposal overcomes the state of the art limitations for the generation of light beams far from the visible domain carrying non-integer orbital angular momentum and could be applied in fields such as diffraction imaging, EUV lithography, particle trapping, and super-resolution imaging.

  16. Invisible marking system by extreme ultraviolet radiation: the new frontier for anti-counterfeiting tags

    NASA Astrophysics Data System (ADS)

    Di Lazzaro, P.; Bollanti, S.; Flora, F.; Mezi, L.; Murra, D.; Torre, A.; Bonfigli, F.; Montereali, R. M.; Vincenti, M. A.

    2016-07-01

    We present a marking technology which uses extreme ultraviolet radiation to write invisible patterns on tags based on alkali fluoride thin films. The shape of the pattern is pre-determined by a mask (in the case of contact lithography) or by a suitable mirror (projection lithography). Tags marked using this method offer a much better protection against fakes than currently available anti-counterfeiting techniques. The complexity and cost of this technology can be tailored to the value of the good to be protected, leaving, on the other hand, the specific reading technique straightforward. So far, we have exploited our invisible marking to tag artworks, identity cards, electrical components, and containers of radioactive wastes. Advantages and limits of this technology are discussed in comparison with the anti-counterfeiting systems available in the market.

  17. Modeling and measuring the transport and scattering of energetic debris in an extreme ultraviolet plasma source

    NASA Astrophysics Data System (ADS)

    Sporre, John R.; Elg, Daniel T.; Kalathiparambil, Kishor K.; Ruzic, David N.

    2016-01-01

    A theoretical model for describing the propagation and scattering of energetic species in an extreme ultraviolet (EUV) light lithography source is presented. An EUV light emitting XTREME XTS 13-35 Z-pinch plasma source is modeled with a focus on the effect of chamber pressure and buffer gas mass on energetic ion and neutral debris transport. The interactions of the energetic debris species, which is generated by the EUV light emitting plasma, with the buffer gas and chamber walls are considered as scattering events in the model, and the trajectories of the individual atomic species involved are traced using a Monte Carlo algorithm. This study aims to establish the means by which debris is transported to the intermediate focus with the intent to verify the various mitigation techniques currently employed to increase EUV lithography efficiency. The modeling is compared with an experimental investigation.

  18. Relativistic electron mirrors from nanoscale foils for coherent frequency upshift to the extreme ultraviolet.

    PubMed

    Kiefer, D; Yeung, M; Dzelzainis, T; Foster, P S; Rykovanov, S G; Lewis, C Ls; Marjoribanks, R S; Ruhl, H; Habs, D; Schreiber, J; Zepf, M; Dromey, B

    2013-01-01

    Reflecting light from a mirror moving close to the speed of light has been envisioned as a route towards producing bright X-ray pulses since Einstein's seminal work on special relativity. For an ideal relativistic mirror, the peak power of the reflected radiation can substantially exceed that of the incident radiation due to the increase in photon energy and accompanying temporal compression. Here we demonstrate for the first time that dense relativistic electron mirrors can be created from the interaction of a high-intensity laser pulse with a freestanding, nanometre-scale thin foil. The mirror structures are shown to shift the frequency of a counter-propagating laser pulse coherently from the infrared to the extreme ultraviolet with an efficiency >10(4) times higher than in the case of incoherent scattering. Our results elucidate the reflection process of laser-generated electron mirrors and give clear guidance for future developments of a relativistic mirror structure.

  19. Correlated proton-electron hole dynamics in protonated water clusters upon extreme ultraviolet photoionization

    DOE PAGES

    Li, Zheng; Vendrell, Oriol

    2016-01-13

    The ultrafast nuclear and electronic dynamics of protonated water clusters H+(H2O)n after extreme ultraviolet photoionization is investigated. In particular, we focus on cluster cations with n = 3, 6, and 21. Upon ionization, two positive charges are present in the cluster related to the excess proton and the missing electron, respectively. A correlation is found between the cluster's geometrical conformation and initial electronic energy with the size of the final fragments produced. As a result, for situations in which the electron hole and proton are initially spatially close, the two entities become correlated and separate in a time-scale of 20more » to 40 fs driven by strong non-adiabatic effects.« less

  20. Correlated proton-electron hole dynamics in protonated water clusters upon extreme ultraviolet photoionization

    SciTech Connect

    Li, Zheng; Vendrell, Oriol

    2016-01-13

    The ultrafast nuclear and electronic dynamics of protonated water clusters H+(H2O)n after extreme ultraviolet photoionization is investigated. In particular, we focus on cluster cations with n = 3, 6, and 21. Upon ionization, two positive charges are present in the cluster related to the excess proton and the missing electron, respectively. A correlation is found between the cluster's geometrical conformation and initial electronic energy with the size of the final fragments produced. As a result, for situations in which the electron hole and proton are initially spatially close, the two entities become correlated and separate in a time-scale of 20 to 40 fs driven by strong non-adiabatic effects.

  1. Correlated proton-electron hole dynamics in protonated water clusters upon extreme ultraviolet photoionization.

    PubMed

    Li, Zheng; Vendrell, Oriol

    2016-07-01

    The ultrafast nuclear and electronic dynamics of protonated water clusters H(+)(H2O) n after extreme ultraviolet photoionization is investigated. In particular, we focus on cluster cations with n = 3, 6, and 21. Upon ionization, two positive charges are present in the cluster related to the excess proton and the missing electron, respectively. A correlation is found between the cluster's geometrical conformation and initial electronic energy with the size of the final fragments produced. For situations in which the electron hole and proton are initially spatially close, the two entities become correlated and separate in a time-scale of 20 to 40 fs driven by strong non-adiabatic effects.

  2. Limitations in photoionization of helium by an extreme ultraviolet optical vortex

    NASA Astrophysics Data System (ADS)

    Kaneyasu, T.; Hikosaka, Y.; Fujimoto, M.; Konomi, T.; Katoh, M.; Iwayama, H.; Shigemasa, E.

    2017-02-01

    Photoelectron angular distributions from helium atoms are measured using the circularly polarized extreme ultraviolet (XUV) vortex produced by a helical undulator as the higher harmonics of its radiation. The XUV vortex has a helical wave front and carries orbital angular momentum as well as the spin angular momentum associated with its circular polarization. While the violation of the electric dipole transition rules has been predicted for interactions between vortices and atoms, the photoelectron angular distributions are well reproduced by assuming electric dipole transitions only. This observation can be explained by the localized nature of the helical phase effect of the vortex on the interaction with atoms, and demonstrates that nondipole interactions induced by the XUV vortex are hardly observable in conventional gas-phase experiments.

  3. The expansion velocities of laser-produced plasmas determined from extreme ultraviolet spectral line profiles

    NASA Technical Reports Server (NTRS)

    Feldman, U.; Doschek, G. A.; Behring, W. E.; Cohen, L.

    1977-01-01

    The expansion of laser-produced plasma is determined from the shapes of spectral lines of highly ionized iron emitted in the extreme ultraviolet. The plasmas were produced by focusing the pulse from a Nd:glass laser onto solid planar targets, and spectra were recorded with a high-resolution grazing-incidence spectrograph. From the Doppler broadening of lines of Fe XX and Fe XXI, expansion velocities of about 830 km/s were determined. The relative time-averaged ion abundances of Fe XVIII, Fe XIX, Fe XX, and Fe XXI are estimated for three different spectra. The abundances do not differ by more than a factor of 4 for any of the spectra.

  4. Extreme ultraviolet proximity lithography for fast, flexible and parallel fabrication of infrared antennas.

    PubMed

    Kunkemöller, Georg; Mass, Tobias W W; Michel, Ann-Katrin U; Kim, Hyun-Su; Brose, Sascha; Danylyuk, Serhiy; Taubner, Thomas; Juschkin, Larissa

    2015-10-05

    We present a method for fabrication of large arrays of nano-antennas using extreme-ultraviolet (EUV) illumination. A discharge-produced plasma source generating EUV radiation around 10.88 nm wavelength is used for the illumination of a photoresist via a mask in a proximity printing setup. The method of metallic nanoantennas fabrication utilizes a bilayer photoresist and employs a lift-off process. The impact of Fresnel-diffraction of EUV light in the mask on a shape of the nanostructures has been investigated. It is shown how by the use of the same rectangular apertures in the transmission mask, antennas of various shapes can be fabricated. Using Fourier transform infrared spectroscopy, spectra of antennas reflectivity were measured and compared to FDTD simulations demonstrating good agreement.

  5. Radiative heating of thin Al foils by intense extreme ultraviolet radiation

    NASA Astrophysics Data System (ADS)

    Grabovski, E. V.; Sasorov, P. V.; Shevelko, A. P.; Aleksandrov, V. V.; Andreev, S. N.; Basko, M. M.; Branitski, A. V.; Gritsuk, A. N.; Volkov, G. S.; Laukhin, Ya. N.; Mitrofanov, K. N.; Novikov, V. G.; Oleinik, G. M.; Samokhin, A. A.; Smirnov, V. P.; Tolstikhina, I. Yu.; Frolov, I. N.; Yakushev, O. F.

    2016-03-01

    The effect of induced transparency of thin Al foils radiatively heated by intense extreme ultraviolet (EVU) radiation has been observed. The radiation of the plasma of Z-pinches appearing under the compression of tungsten liners at the Angara-5-1 facility has been used as the radiation that heats the Al foil (peak illumination on the foil ~0.55 TW/cm2) and is transmitted through it. The photoabsorption has been studied in the formed aluminum plasma at temperatures of ~10-30 eV in the density range of ~1-20 mg/cm3 in the wavelength range of ~5-24 nm. Absorption lines of Al4+...7+ ions have been identified in the experimental spectrum. In addition, radiative gas-dynamic simulations of the foil heating and expansion have been performed taking into account radiation transfer processes.

  6. A solar extreme ultraviolet telescope and spectrograph for space shuttle. Volume 1: Investigation and technical plan

    NASA Technical Reports Server (NTRS)

    Neupert, W. M.

    1978-01-01

    A scientific investigation of heating and mass transport in the solar corona that is currently planned for a future Shuttle/Spacelab flight is outlined. The instrument to be used is a near-normal incidence grating spectrograph fed by a grazing incidence Wolter Type 2 telescope. A toroidal grating design provides stigmatic images of the corona up to 8 arc min in extent over the spectral region from 225 A to 370 A. Spatial resolution of at least 2 arc sec and spectral resolution of 0.050 A is achievable throughout the central 4 arc min field or view. Primary scientific data are recorded on Schumann-type film. An H-alpha slit jaw monitor and zero order extreme ultraviolet monitor are also planned to support instrument operation.

  7. Extreme ultraviolet imaging of three-dimensional magnetic reconnection in a solar eruption.

    PubMed

    Sun, J Q; Cheng, X; Ding, M D; Guo, Y; Priest, E R; Parnell, C E; Edwards, S J; Zhang, J; Chen, P F; Fang, C

    2015-06-26

    Magnetic reconnection, a change of magnetic field connectivity, is a fundamental physical process in which magnetic energy is released explosively, and it is responsible for various eruptive phenomena in the universe. However, this process is difficult to observe directly. Here, the magnetic topology associated with a solar reconnection event is studied in three dimensions using the combined perspectives of two spacecraft. The sequence of extreme ultraviolet images clearly shows that two groups of oppositely directed and non-coplanar magnetic loops gradually approach each other, forming a separator or quasi-separator and then reconnecting. The plasma near the reconnection site is subsequently heated from ∼1 to ≥5 MK. Shortly afterwards, warm flare loops (∼3 MK) appear underneath the hot plasma. Other observational signatures of reconnection, including plasma inflows and downflows, are unambiguously revealed and quantitatively measured. These observations provide direct evidence of magnetic reconnection in a three-dimensional configuration and reveal its origin.

  8. Extreme ultraviolet (EUV) surface modification of polytetrafluoroethylene (PTFE) for control of biocompatibility

    NASA Astrophysics Data System (ADS)

    Ahad, Inam Ul; Butruk, Beata; Ayele, Mesfin; Budner, Bogusław; Bartnik, Andrzej; Fiedorowicz, Henryk; Ciach, Tomasz; Brabazon, Dermot

    2015-12-01

    Extreme ultraviolet (EUV) surface modification of polytetrafluoroethylene (PTFE) was performed in order to enhance the degree of biocompatibility. Polymer samples were irradiated by different number of EUV shots using a laser-plasma based EUV source in the presence of nitrogen gas. The physical and chemical properties of EUV modified PTFE samples were studied using Atomic Force Microscopy, X-ray photoelectron spectroscopy and water contact angle (WCA) methods. Pronounced wall type micro and nano-structures appeared on the EUV treated polymer surfaces resulting in increased surface roughness and hydrophobicity. Stronger cell adhesion and good cell morphology were observed on EUV modified surfaces by in-vitro cell culture studies performed using L929 fibroblasts.

  9. Aspherical surfaces design for extreme ultraviolet lithographic objective with correction of thermal aberration

    NASA Astrophysics Data System (ADS)

    Liu, Yan; Li, Yanqiu

    2016-09-01

    At present, few projection objectives for extreme ultraviolet (EUV) lithography pay attention to correct thermal aberration in optical design phase, which would lead to poor image quality in a practical working environment. We present an aspherical modification method for helping the EUV lithographic objective additionally correct the thermal aberration. Based on the thermal aberration and deformation predicted by integrated optomechanical analysis, the aspherical surfaces in an objective are modified by an iterative algorithm. The modified aspherical surfaces could correct the thermal aberration and maintain the initial high image quality in a practical working environment. A six-mirror EUV lithographic objective with 0.33-numerical aperture is taken as an example to illustrate the presented method. The results show that the thermal aberration can be corrected effectively, and the image quality of the thermally deformed system is improved to the initial design level, which proves the availability of the method.

  10. Extreme Ultra-Violet Spectroscopy of the Lower Solar Atmosphere During Solar Flares (Invited Review)

    NASA Astrophysics Data System (ADS)

    Milligan, Ryan O.

    2015-12-01

    The extreme ultra-violet (EUV) portion of the solar spectrum contains a wealth of diagnostic tools for probing the lower solar atmosphere in response to an injection of energy, particularly during the impulsive phase of solar flares. These include temperature- and density-sensitive line ratios, Doppler-shifted emission lines, nonthermal broadening, abundance measurements, differential emission measure profiles, continuum temperatures and energetics, among others. In this article I review some of the recent advances that have been made using these techniques to infer physical properties of heated plasma at footpoint and ribbon locations during the initial stages of solar flares. I primarily focus on studies that have utilised spectroscopic EUV data from Hinode/EUV Imaging Spectrometer (EIS) and Solar Dynamics Observatory/EUV Variability Experiment (SDO/EVE), and I also provide some historical background and a summary of future spectroscopic instrumentation.

  11. Nonperturbative Twist in the Generation of Extreme-Ultraviolet Vortex Beams

    NASA Astrophysics Data System (ADS)

    Rego, Laura; Román, Julio San; Picón, Antonio; Plaja, Luis; Hernández-García, Carlos

    2016-10-01

    High-order harmonic generation (HHG) has been recently proven to produce extreme-ultraviolet (XUV) vortices from the nonlinear conversion of infrared twisted beams. Previous works have demonstrated a linear scaling law of the vortex charge with the harmonic order. We demonstrate that this simple law hides an unexpectedly rich scenario for the buildup of orbital angular momentum (OAM) due to the nonperturbative behavior of HHG. The complexity of these twisted XUV beams appears only when HHG is driven by nonpure vortex modes, where the XUV OAM content is dramatically increased. We explore the underlying mechanisms for this diversity and derive a general conservation rule for the nonperturbative OAM buildup. The simple scaling found in previous works corresponds to the collapse of this scenario for the particular case of pure (single-mode) OAM driving fields.

  12. Extreme ultraviolet diagnosis of a neutral-beam-heated mirror machine

    SciTech Connect

    Drake, R.P.

    1980-07-01

    Extreme ultraviolet emissions from the LLL 2XIIB fusion research experiment have been studied. (2XIIB was a magnetic-mirror-plasma-confinement device; beams of high-energy (20 keV) neutral deuterium created a high-density, high-temperature plasma.) A normal-incidence concave-grating monochromator, equipped with a windowless photomultiplier tube, was used to measure emissions in the spectral region from 400 Angstrom to 1600 A. Emissions of oxygen, titanium, carbon, nitrogen, and deuterium were identified; the oxygen brightnesses at times exceeded 10/sup 18/ ph-s/sup -1/-cm/sup -2/-sr/sup -1/. A survey of the emission characteristics found the oxygen concentration was 3%, the other impurities had concentrations near 0.4%. The radiated power loss was about 5% of the deposited neutral beam power.

  13. Numerical evaluation of a 13.5-nm high-brightness microplasma extreme ultraviolet source

    SciTech Connect

    Hara, Hiroyuki Arai, Goki; Dinh, Thanh-Hung; Higashiguchi, Takeshi; Jiang, Weihua; Miura, Taisuke; Endo, Akira; Ejima, Takeo; Li, Bowen; Dunne, Padraig; O'Sullivan, Gerry; Sunahara, Atsushi

    2015-11-21

    The extreme ultraviolet (EUV) emission and its spatial distribution as well as plasma parameters in a microplasma high-brightness light source are characterized by the use of a two-dimensional radiation hydrodynamic simulation. The expected EUV source size, which is determined by the expansion of the microplasma due to hydrodynamic motion, was evaluated to be 16 μm (full width) and was almost reproduced by the experimental result which showed an emission source diameter of 18–20 μm at a laser pulse duration of 150 ps [full width at half-maximum]. The numerical simulation suggests that high brightness EUV sources should be produced by use of a dot target based microplasma with a source diameter of about 20 μm.

  14. Colliding laser-produced plasmas as targets for laser-generated extreme ultraviolet sources

    SciTech Connect

    Cummins, T.; O'Gorman, C.; Dunne, P.; Sokell, E.; O'Sullivan, G.; Hayden, P.

    2014-07-28

    Colliding plasmas produced by neodymium-doped yttrium aluminium garnet (Nd:YAG) laser illumination of tin wedge targets form stagnation layers, the physical parameters of which can be controlled to optimise coupling with a carbon dioxide (CO{sub 2}) heating laser pulse and subsequent extreme ultraviolet (EUV) production. The conversion efficiency (CE) of total laser energy into EUV emission at 13.5 nm ± 1% was 3.6%. Neglecting both the energy required to form the stagnation layer and the EUV light produced before the CO{sub 2} laser pulse is incident results in a CE of 5.1% of the CO{sub 2} laser energy into EUV light.

  15. Generation of isolated attosecond extreme ultraviolet pulses employing nanoplasmonic field enhancement: optimization of coupled ellipsoids

    NASA Astrophysics Data System (ADS)

    Stebbings, S. L.; Süßmann, F.; Yang, Y.-Y.; Scrinzi, A.; Durach, M.; Rusina, A.; Stockman, M. I.; Kling, M. F.

    2011-07-01

    The production of extreme ultraviolet (XUV) radiation via nanoplasmonic field-enhanced high-harmonic generation (HHG) in gold nanostructures at MHz repetition rates is investigated theoretically in this paper. Analytical and numerical calculations are employed and compared in order to determine the plasmonic fields in gold ellipsoidal nanoparticles. The comparison indicates that numerical calculations can accurately predict the field enhancement and plasmonic decay, but may encounter difficulties when attempting to predict the oscillatory behavior of the plasmonic field. Numerical calculations for coupled symmetric and asymmetric ellipsoids for different carrier-envelope phases (CEPs) of the driving laser field are combined with time-dependent Schrödinger equation simulations to predict the resulting HHG spectra. The studies reveal that the plasmonic field oscillations, which are controlled by the CEP of the driving laser field, play a more important role than the nanostructure configuration in finding the optimal conditions for the generation of isolated attosecond XUV pulses via nanoplasmonic field enhancement.

  16. Cluster beam targets for laser plasma extreme ultraviolet and soft x-ray sources

    DOEpatents

    Kublak, G.D.; Richardson, M.C.

    1996-11-19

    Method and apparatus for producing extreme ultraviolet (EUV) and soft x-ray radiation from an ultra-low debris plasma source are disclosed. Targets are produced by the free jet expansion of various gases through a temperature controlled nozzle to form molecular clusters. These target clusters are subsequently irradiated with commercially available lasers of moderate intensity (10{sup 11}--10{sup 12} watts/cm{sup 2}) to produce a plasma radiating in the region of 0.5 to 100 nanometers. By appropriate adjustment of the experimental conditions the laser focus can be moved 10--30 mm from the nozzle thereby eliminating debris produced by plasma erosion of the nozzle. 5 figs.

  17. Study of an astronomical extreme ultraviolet rocket spectrometer for use on shuttle missions

    NASA Technical Reports Server (NTRS)

    Bowyer, C. S.

    1977-01-01

    The adaptation of an extreme ultraviolet astronomy rocket payload for flight on the shuttle was studied. A sample payload for determining integration and flight procedures for experiments which may typically be flown on shuttle missions was provided. The electrical, mechanical, thermal, and operational interface requirements between the payload and the orbiter were examined. Of particular concern was establishing a baseline payload accommodation which utilizes proven common hardware for electrical, data, command, and possibly real time monitoring functions. The instrument integration and checkout procedures necessary to assure satisfactory in-orbit instrument performance were defined and those procedures which can be implemented in such a way as to minimize their impact on orbiter integration schedules were identified.

  18. Interplay of electron heating and saturable absorption in ultrafast extreme ultraviolet transmission of condensed matter

    NASA Astrophysics Data System (ADS)

    Di Cicco, Andrea; Hatada, Keisuke; Giangrisostomi, Erika; Gunnella, Roberto; Bencivenga, Filippo; Principi, Emiliano; Masciovecchio, Claudio; Filipponi, Adriano

    2014-12-01

    High intensity pulses obtained by modern extreme ultraviolet (EUV) and x-ray photon sources allows the observation of peculiar phenomena in condensed matter. Experiments performed at the Fermi@Elettra FEL-1 free-electron-laser source at 23.7, 33.5, and 37.5 eV on Al thin films, for an intermediate-fluence range up to about 20 J /cm2, show evidence for a nonmonotonic EUV transmission trend. A decreasing transmission up to about 5 -10 J /cm2 is followed by an increase at higher fluence, associated with saturable absorption effects. The present findings are interpreted within a simplified three-channel model, showing that an account of the interplay between ultrafast electron heating and saturation effects is required to explain the observed transmission trend.

  19. Acid generation mechanism in anion-bound chemically amplified resists used for extreme ultraviolet lithography

    NASA Astrophysics Data System (ADS)

    Komuro, Yoshitaka; Yamamoto, Hiroki; Kobayashi, Kazuo; Ohomori, Katsumi; Kozawa, Takahiro

    2015-03-01

    Extreme ultraviolet (EUV) lithography is the most promising candidate for the high-volume production of semiconductor devices with half-pitches of sub 10nm. An anion-bound polymer(ABP), in which at the anion part of onium salts is polymerized, has attracted much attention from the viewpoint of the control of acid diffusion. In this study, the acid generation mechanism in ABP films was investigated using γ and EUV radiolysis. On the basis of experimental results, the acid generation mechanism in anion-bound chemically amplified resists was proposed. The protons of acids are considered to be mainly generated through the reaction of phenyl radicals with diphenylsulfide radical cations that are produced through the hole transfer to the decomposition products of onium salts.

  20. Acid generation mechanism in anion-bound chemically amplified resists used for extreme ultraviolet lithography

    NASA Astrophysics Data System (ADS)

    Komuro, Yoshitaka; Yamamoto, Hiroki; Kobayashi, Kazuo; Utsumi, Yoshiyuki; Ohomori, Katsumi; Kozawa, Takahiro

    2014-11-01

    Extreme ultraviolet (EUV) lithography is the most promising candidate for the high-volume production of semiconductor devices with half-pitches of sub-10 nm. An anion-bound polymer (ABP), in which the anion part of onium salts is polymerized, has attracted much attention from the viewpoint of the control of acid diffusion. In this study, the acid generation mechanism in ABP films was investigated using electron (pulse), γ, and EUV radiolyses. On the basis of experimental results, the acid generation mechanism in anion-bound chemically amplified resists was proposed. The major path for proton generation in the absence of effective proton sources is considered to be the reaction of phenyl radicals with diphenylsulfide radical cations that are produced through hole transfer to the decomposition products of onium salts.

  1. Three-dimensional nanoscale molecular imaging by extreme ultraviolet laser ablation mass spectrometry

    PubMed Central

    Kuznetsov, Ilya; Filevich, Jorge; Dong, Feng; Woolston, Mark; Chao, Weilun; Anderson, Erik H.; Bernstein, Elliot R.; Crick, Dean C.; Rocca, Jorge J.; Menoni, Carmen S.

    2015-01-01

    Analytical probes capable of mapping molecular composition at the nanoscale are of critical importance to materials research, biology and medicine. Mass spectral imaging makes it possible to visualize the spatial organization of multiple molecular components at a sample's surface. However, it is challenging for mass spectral imaging to map molecular composition in three dimensions (3D) with submicron resolution. Here we describe a mass spectral imaging method that exploits the high 3D localization of absorbed extreme ultraviolet laser light and its fundamentally distinct interaction with matter to determine molecular composition from a volume as small as 50 zl in a single laser shot. Molecular imaging with a lateral resolution of 75 nm and a depth resolution of 20 nm is demonstrated. These results open opportunities to visualize chemical composition and chemical changes in 3D at the nanoscale. PMID:25903827

  2. Shot noise limit of sensitivity of chemically amplified resists used for extreme ultraviolet lithography

    NASA Astrophysics Data System (ADS)

    Fujii, Shinya; Kozawa, Takahiro; Okamoto, Kazumasa; Santillan, Julius Joseph; Itani, Toshiro

    2015-11-01

    With the improvement of resolution, the shot noise effect becomes a serious concern in the lithography used for high-volume production of semiconductor devices. In this study, the shot noise limit of the sensitivity of chemically amplified resists was investigated from the viewpoint of sensitivity enhancement, assuming extreme ultraviolet lithography. The latent images of line-and-space patterns with 11 nm half-pitch were calculated using a Monte Carlo method. The effect of secondary electron blur was eliminated to clarify the shot noise limit of line edge roughness (LER). When the requirement for line width roughness (LWR) was assumed to be 10% critical dimension (CD), the shot noise limit of sensitivity was >100 mJ cm-2. For the 20% CD LWR, the shot noise limits of sensitivity for the 10, 20, and 30 wt % acid generator concentrations were 20, 9, and 7 mJ cm-2, respectively.

  3. Data processing and initial results from the CE-3 Extreme Ultraviolet Camera

    NASA Astrophysics Data System (ADS)

    Feng, Jian-Qing; Liu, Jian-Jun; He, Fei; Yan, Wei; Ren, Xin; Tan, Xu; He, Ling-Ping; Chen, Bo; Zuo, Wei; Wen, Wei-Bin; Su, Yan; Zou, Yong-Liao; Li, Chun-Lai

    2014-12-01

    The Extreme Ultraviolet Camera (EUVC) onboard the Chang'e-3 (CE-3) lander is used to observe the structure and dynamics of Earth's plasmasphere from the Moon. By detecting the resonance line emission of helium ions (He+) at 30.4 nm, the EUVC images the entire plasmasphere with a time resolution of 10 min and a spatial resolution of about 0.1 Earth radius (RE) in a single frame. We first present details about the data processing from EUVC and the data acquisition in the commissioning phase, and then report some initial results, which reflect the basic features of the plasmasphere well. The photon count and emission intensity of EUVC are consistent with previous observations and models, which indicate that the EUVC works normally and can provide high quality data for future studies.

  4. Stochastic effects in 11 nm imaging of extreme ultraviolet lithography with chemically amplified resists

    NASA Astrophysics Data System (ADS)

    Kozawa, Takahiro; Santillan, Julius Joseph; Itani, Toshiro

    2014-03-01

    The resolution of extreme ultraviolet (EUV) lithography with chemically amplified resist processes has reached 16 nm (half-pitch). The development of chemically amplified resists is ongoing toward the 11 nm node. However, the stochastic effects are increasingly becoming a significant concern with the continuing shrinkage of features. In this study, the fluctuation of protected unit distribution caused by the stochastic effects during image formation was investigated assuming line-and-space patterns with 11 nm half-pitch. Contrary to expectations, the standard deviation of the number of protected units connected to a polymer after postexposure baking (PEB) did not differ from that for 16 nm half-pitch. The standard deviation after PEB increased with the effective reaction radius for deprotection and the initial standard deviation before PEB. Because of the severe requirements for resist processes, the stochastic effects in chemical reactions should be taken into account in the design of next-generation resists.

  5. Time exposure performance of Mo-Au Gibbsian segregating alloys for extreme ultraviolet collector optics.

    PubMed

    Qiu, Huatan; Srivastava, Shailendra N; Thompson, Keith C; Neumann, Martin J; Ruzic, David N

    2008-05-01

    Successful implementation of extreme ultraviolet (EUV) lithography depends on research and progress toward minimizing collector optics degradation from intense plasma erosion and debris deposition. Thus studying the surface degradation process and implementing innovative methods, which could enhance the surface chemistry causing the mirrors to suffer less damage, is crucial for this technology development. A Mo-Au Gibbsian segregation (GS) alloy is deposited on Si using a dc dual-magnetron cosputtering system and the damage is investigated as a result of time dependent exposure in an EUV source. A thin Au segregating layer is maintained through segregation during exposure, even though overall erosion in the Mo-Au sample is taking place in the bulk. The reflective material, Mo, underneath the segregating layer is protected by this sacrificial layer, which is lost due to preferential sputtering. In addition to theoretical work, experimental results are presented on the effectiveness of the GS alloys to be used as potential EUV collector optics material.

  6. Design and performance of the telescope and detector covers on the Extreme Ultraviolet Explorer satellite

    NASA Technical Reports Server (NTRS)

    Tom, James L.

    1994-01-01

    Two cover mechanisms were designed and developed for the Extreme Ultraviolet Explorer (EUVE) science payload to keep the EUVE telescope mirrors and detectors sealed from the atmospheric environment until the spacecraft was placed into orbit. There were four telescope front covers and seven motorized detector covers on the EUVE science payload. The EUVE satellite was launched into orbit in June 1992 and all the covers operated successfully after launch. This success can be attributed to high design margins and extensive testing at each level of assembly. This paper described the design of the telescope front covers and the motorized detector covers. This paper also discusses some of the many design considerations and modifications made as performance and reliability problems became apparent from each phase of testing.

  7. Resonant two-photon absorption of extreme-ultraviolet free-electron-laser radiation in helium

    SciTech Connect

    Nagasono, Mitsuru; Suljoti, Edlira; Pietzsch, Annette; Hennies, Franz; Wellhoefer, Michael; Hoeft, Jon-Tobias; Martins, Michael; Wurth, Wilfried; Foehlisch, Alexander; Treusch, Rolf; Feldhaus, Josef; Schneider, Jochen R.

    2007-05-15

    We have investigated the nonlinear response of helium to intense extreme-ultraviolet radiation from the free-electron laser in Hamburg (FLASH). We observe a spectral feature between 24 and 26 eV electron kinetic energy in photoemission which shows a quadratic fluence dependence. The feature is explained as a result of subsequent processes involving a resonant two-photon absorption process into doubly excited levels of even parity (N=5 and 6), radiative decay to the doubly excited states in the vicinity of the He{sup +} (N=2) ionization threshold and finally the photoionization of the inner electron by the radiation of the next microbunches. This observation suggests that even-parity states, which have been elusive to be measured with the low pulse energy of synchrotron radiation sources, can be investigated with the intense radiation of FLASH. This also demonstrates a first step to bring nonlinear spectroscopy into the xuv and soft-x-ray regime.

  8. Observation of molecular hyperfine structure in the extreme ultraviolet: The HF C-X spectrum.

    PubMed

    Philippson, Jeffrey N; Shiell, Ralph C; Reinhold, Elmar; Ubachs, Wim

    2008-11-07

    Clearly resolved hyperfine structure has been observed in the extreme ultraviolet (XUV) spectra of the C (1)Pi, v=0-X (1)Sigma(+), v=0 transition of H(19)F obtained through 1 XUV+1 UV resonance enhanced multiphoton ionization spectroscopy. The hyperfine splitting within the R-branch lines shows significant perturbations, which we attribute to mixing with the rotational levels of the nearby v=29 level of the B (1)Sigma(+) ion-pair state. A deperturbation analysis quantitatively explains the apparent variation of the fluorine magnetic hyperfine parameter a(F), for which a value of 4034(83) MHz was obtained by averaging over the values derived from the R(0)-R(4) lines, after correcting for the effects of the perturbations.

  9. The ion microscope as a tool for quantitative measurements in the extreme ultraviolet

    PubMed Central

    Tsatrafyllis, N.; Bergues, B.; Schröder, H.; Veisz, L.; Skantzakis, E.; Gray, D.; Bodi, B.; Kuhn, S.; Tsakiris, G. D.; Charalambidis, D.; Tzallas, P.

    2016-01-01

    We demonstrate a tool for quantitative measurements in the extreme ultraviolet (EUV) spectral region measuring spatially resolved atomic ionization products at the focus of an EUV beam. The ionizing radiation is a comb of the 11th–15th harmonics of a Ti:Sapphire femtosecond laser beam produced in a Xenon gas jet. The spatial ion distribution at the focus of the harmonics is recorded using an ion microscope. Spatially resolved single- and two-photon ionization products of Argon and Helium are observed. From such ion distributions single- and two-photon generalized cross sections can be extracted by a self-calibrating method. The observation of spatially resolved two-EUV-photon ionization constitutes an initial step towards future single-shot temporal characterization of attosecond pulses. PMID:26868370

  10. Extreme ultraviolet spectroscopy and atomic models of highly charged heavy ions in the Large Helical Device

    NASA Astrophysics Data System (ADS)

    Suzuki, C.; Murakami, I.; Koike, F.; Tamura, N.; Sakaue, H. A.; Morita, S.; Goto, M.; Kato, D.; Ohashi, H.; Higashiguchi, T.; Sudo, S.; O'Sullivan, G.

    2017-01-01

    We report recent results of extreme ultraviolet (EUV) spectroscopy of highly charged heavy ions in plasmas produced in the Large Helical Device (LHD). The LHD is an ideal source of experimental databases of EUV spectra because of high brightness and low opacity, combined with the availability of pellet injection systems and reliable diagnostic tools. The measured heavy elements include tungsten, tin, lanthanides and bismuth, which are motivated by ITER as well as a variety of plasma applications such as EUV lithography and biological microscopy. The observed spectral features drastically change between quasicontinuum and discrete depending on the plasma temperature, which leads to some new experimental identifications of spectral lines. We have developed collisional-radiative models for some of these ions based on the measurements. The atomic number dependence of the spectral feature is also discussed.

  11. Note: Thermally stable thin-film filters for high-power extreme-ultraviolet applications.

    PubMed

    Tarrio, C; Berg, R F; Lucatorto, T B; Lairson, B; Lopez, H; Ayers, T

    2015-11-01

    We investigated several types of thin-film filters for high intensity work in the extreme-ultraviolet (EUV) spectral range. In our application, with a peak EUV intensity of 2.7 W cm(-2), Ni-mesh-backed Zr filters have a typical lifetime of 20 h, at which point they suffer from pinholes and a 50% loss of transmission. Initial trials with Si filters on Ni meshes resulted in rupture of the filters in less than an hour. A simple thermal calculation showed that the temperature rise in those filters to be about 634 K. A similar calculation indicated that using a finer mesh with thicker wires and made of Cu reduces the temperature increase to about 60 K. We have exposed a Si filter backed by such a mesh for more than 60 h with little loss of transmission and no leaks.

  12. Thermally stable thin-film filters for high-power extreme-ultraviolet applications

    PubMed Central

    Tarrio, C.; Berg, R. F.; Lucatorto, T. B.; Lairson, B.; Lopez, H.; Ayers, T.

    2016-01-01

    We investigated several types of thin-film filters for high intensity work in the extreme-ultraviolet (EUV) spectral range. In our application, with a peak EUV intensity of 2.7 W cm−2, Ni-mesh-backed Zr filters have a typical lifetime of 20 hours, at which point they suffer from pinholes and a 50 % loss of transmission. Initial trials with Si filters on Ni meshes resulted in rupture of the filters in less than an hour. A simple thermal calculation showed that the temperature rise in those filters to be about 634 K. A similar calculation indicated that using a finer mesh with thicker wires and made of Cu reduces the temperature increase to about 60 K. We have exposed a Si filter backed by such a mesh for more than 60 hours with little loss of transmission and no leaks. PMID:26628184

  13. Extreme Ultraviolet Solar Images Televised In-Flight with a Rocket-Borne SEC Vidicon System.

    PubMed

    Tousey, R; Limansky, I

    1972-05-01

    A TV image of the entire sun while an importance 2N solar flare was in progress was recorded in the extreme ultraviolet (XUV) radiation band 171-630 A and transmitted to ground from an Aerobee-150 rocket on 4 November 1969 using S-band telemetry. The camera tube was a Westinghouse Electric Corporation SEC vidicon, with its fiber optic faceplate coated with an XUV to visible conversion layer of p-quaterphenyl. The XUV passband was produced by three 1000-A thick aluminum filters in series together with the platinized reflecting surface of the off-axis paraboloid that imaged the sun. A number of images were recorded with integration times between 1/30 see and 2 sec. Reconstruction of pictures was enhanced by combining several to reduce the noise.

  14. Extreme Ultraviolet Fractional Orbital Angular Momentum Beams from High Harmonic Generation

    NASA Astrophysics Data System (ADS)

    Turpin, Alex; Rego, Laura; Picón, Antonio; San Román, Julio; Hernández-García, Carlos

    2017-03-01

    We investigate theoretically the generation of extreme-ultraviolet (EUV) beams carrying fractional orbital angular momentum. To this end, we drive high-order harmonic generation with infrared conical refraction (CR) beams. We show that the high-order harmonic beams emitted in the EUV/soft x-ray regime preserve the characteristic signatures of the driving beam, namely ringlike transverse intensity profile and CR-like polarization distribution. As a result, through orbital and spin angular momentum conservation, harmonic beams are emitted with fractional orbital angular momentum, and they can be synthesized into structured attosecond helical beams –or “structured attosecond light springs”– with rotating linear polarization along the azimuth. Our proposal overcomes the state of the art limitations for the generation of light beams far from the visible domain carrying non-integer orbital angular momentum and could be applied in fields such as diffraction imaging, EUV lithography, particle trapping, and super-resolution imaging.

  15. Repair of localized defects in multilayer-coated reticle blanks for extreme ultraviolet lithography

    DOEpatents

    Stearns, Daniel G.; Sweeney, Donald W.; Mirkarimi, Paul B.

    2004-11-23

    A method is provided for repairing defects in a multilayer coating layered onto a reticle blank used in an extreme ultraviolet lithography (EUVL) system. Using high lateral spatial resolution, energy is deposited in the multilayer coating in the vicinity of the defect. This can be accomplished using a focused electron beam, focused ion beam or a focused electromagnetic radiation. The absorbed energy will cause a structural modification of the film, producing a localized change in the film thickness. The change in film thickness can be controlled with sub-nanometer accuracy by adjusting the energy dose. The lateral spatial resolution of the thickness modification is controlled by the localization of the energy deposition. The film thickness is adjusted locally to correct the perturbation of the reflected field. For example, when the structural modification is a localized film contraction, the repair of a defect consists of flattening a mound or spreading out the sides of a depression.

  16. Modification of organosilicate glasses low-k films under extreme and vacuum ultraviolet radiation

    NASA Astrophysics Data System (ADS)

    Rakhimova, T. V.; Rakhimov, A. T.; Mankelevich, Yu. A.; Lopaev, D. V.; Kovalev, A. S.; Vasil'eva, A. N.; Proshina, O. V.; Braginsky, O. V.; Zyryanov, S. M.; Kurchikov, K.; Novikova, N. N.; Baklanov, M. R.

    2013-03-01

    Degradation of chemical composition of porous low-k films under extreme and various vacuum ultraviolet emissions is studied using specially developed sources. It is shown that the most significant damage is induced by Xe line emission (147 nm) in comparison with Ar (106 nm), He (58 nm), and Sn (13.5 nm) emissions. No direct damage was detected for 193 nm emission. Photoabsorption cross-sections and photodissociation quantum yields were derived for four films under study. 147 nm photons penetrate deeply into low-k films due to smaller photoabsorption cross-section and still have sufficient energy to excite Si-O-Si matrix and break Si-CH3 bonds.

  17. Minimization of the shadow patterns produced by periodic mesh grids in extreme ultraviolet telescopes.

    PubMed

    Auchère, Frédéric; Rizzi, Julien; Philippon, Anne; Rochus, Pierre

    2011-01-01

    Thin metallic films are used as passband filters in space telescopes operating in the extreme ultraviolet (EUV). Because of their thinness, typically 100 to 200 nm, they are very sensitive to static pressure differentials and to mechanic and acoustic vibrations. Therefore, they are difficult to manage in all phases of a space program, from manufacturing to vacuum testing to launch. A common solution to this problem is to reinforce them with fine mesh grids with pitches ranging from a few hundred micrometers to a few millimeters. Depending on their location in the optical path, the main effect of these periodic grids is either to diffract light or to cast penumbral shadows on the focal plane. In this paper, we analyze the formation of the shadow modulation patterns and derive design rules to minimize their amplitude. The minimization principle is illustrated by an application to a solar EUV telescope.

  18. Latest results from the SEMATECH Berkeley extreme ultraviolet microfield exposure tool

    SciTech Connect

    Naulleau, Patrick; Anderson, Christopher N.; Chiu, Jerrin; Dean, Kim; Denham, Paul; George, Simi; Goldberg, Kenneth A.; Hoef, Brian; Jones, Gideon; Koh, Chawon; La Fontaine, Bruno; Ma, Andy; Montgomery, Warren; Niakoula, Dimitra; Park, Joo-On; Wallow, Tom; Wurm, Stefan

    2008-09-02

    Microfield exposure tools (METs) continue to play a dominant role in the development of extreme ultraviolet (EUV) resists. One of these tools is the 0.3 numerical aperture SEMATECH Berkeley MET operating as a resist and mask test center. Here they present an update on the tool summarizing some of the latest test and characterization results. they provide an update on the long-term aberration stability of the tool and present line-space imaging in chemically amplified photoresist down to the 20-nm half-pitch level. Although resist development has shown substantial progress in the area of resolution, line-edge-roughness (LER) remains a significant concern. Here we present a summary of recent LER performance results and consider the effect of mask contributors to the LER observed from the SEMATECH Berkeley microfield tool.

  19. Contamination control program results from three years of ground operations on the Extreme Ultraviolet Explorer instruments

    NASA Technical Reports Server (NTRS)

    Ray, David C.; Jelinsky, Sharon; Welsh, Barry Y.; Malina, Roger F.

    1990-01-01

    A stringent contamination-control plan has been developed for the optical components of the Extreme Ultraviolet Explorer instruments, whose performance in the 80-900 A wavelength range is highly sensitive to particulate and molecular contamination. The contamination-control program has been implemented over the last three years during assembly, test and calibration phases of the instrument. These phases have now been completed and the optics cavities of the instruments have been sealed until deployment in space. Various approaches are discussed which have been used during ground operations to meet optics' contamination goals within the project schedule and budget. The measured optical properties of EUV witness mirrors are also presented which remained with the flight mirrors during ground operations. These were used to track optical degradation due to contamination from the cleanroom and high-vacuum test-chamber environments.

  20. Methods and apparatus for use with extreme ultraviolet light having contamination protection

    DOEpatents

    Chilese, Francis C.; Torczynski, John R.; Garcia, Rudy; Klebanoff, Leonard E.; Delgado, Gildardo R.; Rader, Daniel J.; Geller, Anthony S.; Gallis, Michail A.

    2016-07-12

    An apparatus for use with extreme ultraviolet (EUV) light comprising A) a duct having a first end opening, a second end opening and an intermediate opening intermediate the first end opening the second end opening, B) an optical component disposed to receive EUV light from the second end opening or to send light through the second end opening, and C) a source of low pressure gas at a first pressure to flow through the duct, the gas having a high transmission of EUV light, fluidly coupled to the intermediate opening. In addition to or rather than gas flow the apparatus may have A) a low pressure gas with a heat control unit thermally coupled to at least one of the duct and the optical component and/or B) a voltage device to generate voltage between a first portion and a second portion of the duet with a grounded insulative portion therebetween.

  1. Phase imaging results of phase defect using micro-coherent extreme ultraviolet scatterometry microscope

    NASA Astrophysics Data System (ADS)

    Harada, Tetsuo; Hashimoto, Hiraku; Amano, Tsuyoshi; Kinoshita, Hiroo; Watanabe, Takeo

    2016-04-01

    To evaluate defects on extreme ultraviolet (EUV) masks at the blank state of manufacturing, we developed a micro-coherent EUV scatterometry microscope (micro-CSM). The illumination source is coherent EUV light with a 140 nm focus diameter on the defect using a Fresnel zone plate. This system directly observes the reflection and diffraction signals from a phase defect. The phase and the intensity image of the defect are reconstructed with the diffraction images using ptychography, which is an algorithm of the coherent diffraction imaging. We observed programmed phase defect on a blank EUV mask. Phase distributions of these programmed defects were well reconstructed quantitatively. The micro-CSM is a very powerful tool to review an EUV phase defect.

  2. A desktop extreme ultraviolet microscope based on a compact laser-plasma light source

    NASA Astrophysics Data System (ADS)

    Wachulak, P. W.; Torrisi, A.; Bartnik, A.; Węgrzyński, Ł.; Fok, T.; Fiedorowicz, H.

    2017-01-01

    A compact, desktop size microscope, based on laser-plasma source and equipped with reflective condenser and diffractive Fresnel zone plate objective, operating in the extreme ultraviolet (EUV) region at the wavelength of 13.8 nm, was developed. The microscope is capable of capturing magnified images of objects with 95-nm full-pitch spatial resolution (48 nm 25-75% KE) and exposure time as low as a few seconds, combining reasonable acquisition conditions with stand-alone desktop footprint. Such EUV microscope can be regarded as a complementary imaging tool to already existing, well-established ones. Details about the microscope, characterization, resolution estimation and real sample images are presented and discussed.

  3. Analysis of extreme-ultraviolet observations of a polar coronal hole

    NASA Technical Reports Server (NTRS)

    Mariska, J. T.

    1978-01-01

    Emission gradient curves for extreme-ultraviolet resonance lines of lithiumlike ions have been constructed from spectroheliograms of a northern polar coronal hole observed on August 14, 1973, with the Harvard experiment on Skylab. An emission-measure analysis indicates both reduced density and coronal temperature in the coronal hole. The boundary geometry of the coronal hole is determined, and a temperature-density model that is consistent with the observed intensities is constructed. The model gives a conductive flux of 60,000 erg/sq cm per sec at 1.03 solar radii. The boundary geometry and density distribution are combined with typical solar-wind parameters at the earth to determine an outflow velocity of 15 km/s at 1.08 solar radii.

  4. Photolithography reaches 6 nm half-pitch using extreme ultraviolet light

    NASA Astrophysics Data System (ADS)

    Fan, Daniel; Ekinci, Yasin

    2016-07-01

    Extreme ultraviolet interference lithography records the interference pattern of two diffracted, coherent light beams, where the pattern resolution is half the diffraction grating resolution. The fabrication of diffraction grating masks by e-beam lithography is restricted by the electron proximity effect and pattern transfer limitations into diffraction efficient materials. By patterning HSQ lines at a relaxed pitch to avoid the electron proximity effect, depositing conformal iridium via atomic layer deposition, followed by ion milling the top and bottom iridium and HSQ removal, we fabricated iridium diffraction gratings at double the line spacing of the original HSQ lines. Line/space patterns of 6-nm half-pitch patterns were achieved using these masks, marking a new record resolution in photolithography.

  5. Serendipitous EUV sources detected during the first year of the Extreme Ultraviolet Explorer right angle program

    NASA Technical Reports Server (NTRS)

    Mcdonald, K.; Craig, N.; Sirk, M. M.; Drake, J. J.; Fruscione, A.; Vallerga, J. V.; Malina, R. F.

    1994-01-01

    We report the detection of 114 extreme ultraviolet (EUV; 58 - 740 A) sources, of which 99 are new serendipitous sources, based on observations made with the imaging telescopes on board the Extreme Ultraviolet Explorer (EUVE) during the Right Angle Program (RAP). These data were obtained using the survey scanners and the Deep Survey instrument during the first year of the spectroscopic guest observer phase of the mission, from January 1993 to January 1994. The data set consists of 162 discrete pointings whose exposure times are typically two orders of magnitude longer than the average exposure times during the EUVE all-sky survey. Based on these results, we can expect that EUVE will serendipitously detect approximately 100 new EUV sources per year, or about one new EUV source per 10 sq deg, during the guest observer phase of the EUVE mission. New EUVE sources of note include one B star and three extragalactic objects. The B star (HR 2875, EUVE J0729 - 38.7) is detected in both the Lexan/B (approximately 100 A) and Al/Ti/C (approximately 200 A) bandpasses, and the detection is shown not to be a result of UV leaks. We suggest that we are detecting EUV and/or soft x rays from a companion to the B star. Three sources, EUVE J2132+10.1, EUVE J2343-14.9, and EUVE J2359-30.6 are identified as the active galactic nuclei MKN 1513, MS2340.9-1511, and 1H2354-315, respectively.

  6. Extreme ultraviolet spectroscopy and photometry of VV Puppis during a high accretion state

    NASA Technical Reports Server (NTRS)

    Vennes, Stephane; Szkody, Paula; Sion, Edward M.; Long, Knox S.

    1995-01-01

    We determine the physical properties of the accretion region of the AM Her-type binary VV Puppis using extreme ultraviolet (EUV) medium-resolution spectroscopy and photometry obtained with the Extreme Ultraviolet Explorer (EUVE) observatory. The EUV continuum from VV Pup was detected in the wavelength range from 75 to 135 A and was simultaneously recorded with the Deep Survey/Spectrometer (DS/S) imaging telescope, allowing for the extraction of an accurate light curve. VV Pup appeared to have entered a high-accretion state just prior to the pointed EUVE observations. We use the EUV light curve to infer the diameter of the accretion region (d = 220 km) assuming a hemispherical geometry and a radius of 9000 km for the white dwarf. We perform a model atmosphere analysis and, based on the light curve properties and assuming a distance of 145 pc, we derive an effective temperature of the accretion region in the range 270,000 is less than T(sub eff) is less than 360,000 K and a neutral hydrogen column density in the local interstellar medium of n(sub H) = 1.9 - 3.7 x 10(exp 19)/sq cm. The total EUV/soft X-ray energy radiated by the accretion region is approximately 3.5 x 10(exp 32) ergs/s. Our results provide a first verification of past suggestions that deep heating of the white dwarf surface produces the soft X-ray flux from the polars. We present a possible detection of O VI absortion features, and we suggest that extensive EUVE observations targeting high-accretion events may result in oxygen and heavier element abundance determination in the accretion region.

  7. Concept Study Report: Extreme-Ultraviolet Imaging Spectrometer Solar-B

    NASA Technical Reports Server (NTRS)

    Doschek, George, A.; Brown, Charles M.; Davila, Joseph M.; Dere, Kenneth P.; Korendyke, Clarence M.; Mariska, John T.; Seely, John F.

    1999-01-01

    We propose a next generation Extreme-ultraviolet Imaging Spectrometer (EIS) that for the first time combines high spectral, spatial, and temporal resolution in a single solar spectroscopic instrument. The instrument consists of a multilayer-coated off-axis telescope mirror and a multilayer-coated grating spectrometer. The telescope mirror forms solar images on the spectrometer entrance slit assembly. The spectrometer forms stigmatic spectra of the solar region located at the slit. This region is selected by the articulated telescope mirror. Monochromatic images are obtained either by rastering the solar region across a narrow entrance slit, or by using a very wide slit (called a slot) in place of the slit. Monochromatic images of the region centered on the slot are obtained in a single exposure. Half of each optic is coated to maximize reflectance at 195 Angstroms; the other half to maximize reflectance at 270 Angstroms. The two Extreme Ultraviolet (EUV) wavelength bands have been selected to maximize spectral and dynamical and plasma diagnostic capabilities. Spectral lines are observed that are formed over a temperature range from about 0.1 MK to about 20 MK. The main EIS instrument characteristics are: wavelength bands - 180 to 204 Angstroms; 250 to 290 Angstroms; spectral resolution - 0.0223 Angstroms/pixel (34.3km/s at 195 Angstroms and 23.6 km/s at 284 Angstroms); slit dimensions - 4 slits, two currently specified dimensions are 1" x 1024" and 50" x 1024" (the slot); largest spatial field of view in a single exposure - 50" x 1024"; highest time resolution for active region velocity studies - 4.4 s.

  8. FIRST OBSERVATIONS OF A DOME-SHAPED LARGE-SCALE CORONAL EXTREME-ULTRAVIOLET WAVE

    SciTech Connect

    Veronig, A. M.; Muhr, N.; Kienreich, I. W.; Temmer, M.; Vrsnak, B.

    2010-06-10

    We present first observations of a dome-shaped large-scale extreme-ultraviolet coronal wave, recorded by the Extreme Ultraviolet Imager instrument on board STEREO-B on 2010 January 17. The main arguments that the observed structure is the wave dome (and not the coronal mass ejection, CME) are (1) the spherical form and sharpness of the dome's outer edge and the erupting CME loops observed inside the dome; (2) the low-coronal wave signatures above the limb perfectly connecting to the on-disk signatures of the wave; (3) the lateral extent of the expanding dome which is much larger than that of the coronal dimming; and (4) the associated high-frequency type II burst indicating shock formation low in the corona. The velocity of the upward expansion of the wave dome (v {approx} 650 km s{sup -1}) is larger than that of the lateral expansion of the wave (v {approx} 280 km s{sup -1}), indicating that the upward dome expansion is driven all the time, and thus depends on the CME speed, whereas in the lateral direction it is freely propagating after the CME lateral expansion stops. We also examine the evolution of the perturbation characteristics: first the perturbation profile steepens and the amplitude increases. Thereafter, the amplitude decreases with r {sup -2.5{+-}0.3}, the width broadens, and the integral below the perturbation remains constant. Our findings are consistent with the spherical expansion and decay of a weakly shocked fast-mode MHD wave.

  9. Synthesis and characterization of attosecond light vortices in the extreme ultraviolet

    PubMed Central

    Géneaux, R.; Camper, A.; Auguste, T.; Gobert, O.; Caillat, J.; Taïeb, R.; Ruchon, T.

    2016-01-01

    Infrared and visible light beams carrying orbital angular momentum (OAM) are currently thoroughly studied for their extremely broad applicative prospects, among which are quantum information, micromachining and diagnostic tools. Here we extend these prospects, presenting a comprehensive study for the synthesis and full characterization of optical vortices carrying OAM in the extreme ultraviolet (XUV) domain. We confirm the upconversion rules of a femtosecond infrared helically phased beam into its high-order harmonics, showing that each harmonic order carries the total number of OAM units absorbed in the process up to very high orders (57). This allows us to synthesize and characterize helically shaped XUV trains of attosecond pulses. To demonstrate a typical use of these new XUV light beams, we show our ability to generate and control, through photoionization, attosecond electron beams carrying OAM. These breakthroughs pave the route for the study of a series of fundamental phenomena and the development of new ultrafast diagnosis tools using either photonic or electronic vortices. PMID:27573787

  10. Chirped pulse amplification in an extreme-ultraviolet free-electron laser

    PubMed Central

    Gauthier, David; Allaria, Enrico; Coreno, Marcello; Cudin, Ivan; Dacasa, Hugo; Danailov, Miltcho Boyanov; Demidovich, Alexander; Di Mitri, Simone; Diviacco, Bruno; Ferrari, Eugenio; Finetti, Paola; Frassetto, Fabio; Garzella, David; Künzel, Swen; Leroux, Vincent; Mahieu, Benoît; Mahne, Nicola; Meyer, Michael; Mazza, Tommaso; Miotti, Paolo; Penco, Giuseppe; Raimondi, Lorenzo; Ribič, Primož Rebernik; Richter, Robert; Roussel, Eléonore; Schulz, Sebastian; Sturari, Luca; Svetina, Cristian; Trovò, Mauro; Walker, Paul Andreas; Zangrando, Marco; Callegari, Carlo; Fajardo, Marta; Poletto, Luca; Zeitoun, Philippe; Giannessi, Luca; De Ninno, Giovanni

    2016-01-01

    Chirped pulse amplification in optical lasers is a revolutionary technique, which allows the generation of extremely powerful femtosecond pulses in the infrared and visible spectral ranges. Such pulses are nowadays an indispensable tool for a myriad of applications, both in fundamental and applied research. In recent years, a strong need emerged for light sources producing ultra-short and intense laser-like X-ray pulses, to be used for experiments in a variety of disciplines, ranging from physics and chemistry to biology and material sciences. This demand was satisfied by the advent of short-wavelength free-electron lasers. However, for any given free-electron laser setup, a limit presently exists in the generation of ultra-short pulses carrying substantial energy. Here we present the experimental implementation of chirped pulse amplification on a seeded free-electron laser in the extreme-ultraviolet, paving the way to the generation of fully coherent sub-femtosecond gigawatt pulses in the water window (2.3–4.4 nm). PMID:27905401

  11. Chirped pulse amplification in an extreme-ultraviolet free-electron laser

    NASA Astrophysics Data System (ADS)

    Gauthier, David; Allaria, Enrico; Coreno, Marcello; Cudin, Ivan; Dacasa, Hugo; Danailov, Miltcho Boyanov; Demidovich, Alexander; di Mitri, Simone; Diviacco, Bruno; Ferrari, Eugenio; Finetti, Paola; Frassetto, Fabio; Garzella, David; Künzel, Swen; Leroux, Vincent; Mahieu, Benoît; Mahne, Nicola; Meyer, Michael; Mazza, Tommaso; Miotti, Paolo; Penco, Giuseppe; Raimondi, Lorenzo; Ribič, Primož Rebernik; Richter, Robert; Roussel, Eléonore; Schulz, Sebastian; Sturari, Luca; Svetina, Cristian; Trovò, Mauro; Walker, Paul Andreas; Zangrando, Marco; Callegari, Carlo; Fajardo, Marta; Poletto, Luca; Zeitoun, Philippe; Giannessi, Luca; de Ninno, Giovanni

    2016-12-01

    Chirped pulse amplification in optical lasers is a revolutionary technique, which allows the generation of extremely powerful femtosecond pulses in the infrared and visible spectral ranges. Such pulses are nowadays an indispensable tool for a myriad of applications, both in fundamental and applied research. In recent years, a strong need emerged for light sources producing ultra-short and intense laser-like X-ray pulses, to be used for experiments in a variety of disciplines, ranging from physics and chemistry to biology and material sciences. This demand was satisfied by the advent of short-wavelength free-electron lasers. However, for any given free-electron laser setup, a limit presently exists in the generation of ultra-short pulses carrying substantial energy. Here we present the experimental implementation of chirped pulse amplification on a seeded free-electron laser in the extreme-ultraviolet, paving the way to the generation of fully coherent sub-femtosecond gigawatt pulses in the water window (2.3-4.4 nm).

  12. Chirped pulse amplification in an extreme-ultraviolet free-electron laser.

    PubMed

    Gauthier, David; Allaria, Enrico; Coreno, Marcello; Cudin, Ivan; Dacasa, Hugo; Danailov, Miltcho Boyanov; Demidovich, Alexander; Di Mitri, Simone; Diviacco, Bruno; Ferrari, Eugenio; Finetti, Paola; Frassetto, Fabio; Garzella, David; Künzel, Swen; Leroux, Vincent; Mahieu, Benoît; Mahne, Nicola; Meyer, Michael; Mazza, Tommaso; Miotti, Paolo; Penco, Giuseppe; Raimondi, Lorenzo; Ribič, Primož Rebernik; Richter, Robert; Roussel, Eléonore; Schulz, Sebastian; Sturari, Luca; Svetina, Cristian; Trovò, Mauro; Walker, Paul Andreas; Zangrando, Marco; Callegari, Carlo; Fajardo, Marta; Poletto, Luca; Zeitoun, Philippe; Giannessi, Luca; De Ninno, Giovanni

    2016-12-01

    Chirped pulse amplification in optical lasers is a revolutionary technique, which allows the generation of extremely powerful femtosecond pulses in the infrared and visible spectral ranges. Such pulses are nowadays an indispensable tool for a myriad of applications, both in fundamental and applied research. In recent years, a strong need emerged for light sources producing ultra-short and intense laser-like X-ray pulses, to be used for experiments in a variety of disciplines, ranging from physics and chemistry to biology and material sciences. This demand was satisfied by the advent of short-wavelength free-electron lasers. However, for any given free-electron laser setup, a limit presently exists in the generation of ultra-short pulses carrying substantial energy. Here we present the experimental implementation of chirped pulse amplification on a seeded free-electron laser in the extreme-ultraviolet, paving the way to the generation of fully coherent sub-femtosecond gigawatt pulses in the water window (2.3-4.4 nm).

  13. Co-Alignment System (CAS) study. Report on task 1-3. [Solar Extreme Ultraviolet Telescope and Spectrometer pointing system

    NASA Technical Reports Server (NTRS)

    Anderson, N. T.

    1980-01-01

    The design of a suitable coalignment system (CAS) for the Solar Extreme Ultraviolet Telescope and Spectrometer (SEUTS) is presented. The CAS provides offset adjustment capabilities to SEUTS which will be mounted on a single large pointing system with other devices. The suitability of existing designs is determined and modifications are suggested.

  14. LONG-TERM (SOLAR CYCLE) VARIATION OF THE EXTREME ULTRAVIOLET RADIATION AND 10.7CENTIMETER FLUX FROM THE SUN.

    DTIC Science & Technology

    The proposal is made that the 10.7-cm flux from the sun , generally regarded as a good index of the solar extreme ultraviolet radiation (EUV), does...in some degree, since many features of the sun vary with the solar cycle. With regard to the radio waves represented by the flux and optical

  15. A fast-time-response extreme ultraviolet spectrometer for measurement of impurity line emissions in the Experimental Advanced Superconducting Tokamak

    SciTech Connect

    Zhang, Ling; Xu, Zong; Wu, Zhenwei; Zhang, Pengfei; Wu, Chengrui; Gao, Wei; Shen, Junsong; Chen, Yingjie; Liu, Xiang; Wang, Yumin; Gong, Xianzu; Hu, Liqun; Chen, Junlin; Zhang, Xiaodong; Wan, Baonian; Li, Jiangang; Morita, Shigeru; Ohishi, Tetsutarou; Goto, Motoshi; Dong, Chunfeng; and others

    2015-12-15

    A flat-field extreme ultraviolet (EUV) spectrometer working in the 20-500 Å wavelength range with fast time response has been newly developed to measure line emissions from highly ionized tungsten in the Experimental Advanced Superconducting Tokamak (EAST) with a tungsten divertor, while the monitoring of light and medium impurities is also an aim in the present development. A flat-field focal plane for spectral image detection is made by a laminar-type varied-line-spacing concave holographic grating with an angle of incidence of 87°. A back-illuminated charge-coupled device (CCD) with a total size of 26.6 × 6.6 mm{sup 2} and pixel numbers of 1024 × 255 (26 × 26 μm{sup 2}/pixel) is used for recording the focal image of spectral lines. An excellent spectral resolution of Δλ{sub 0} = 3-4 pixels, where Δλ{sub 0} is defined as full width at the foot position of a spectral line, is obtained at the 80-400 Å wavelength range after careful adjustment of the grating and CCD positions. The high signal readout rate of the CCD can improve the temporal resolution of time-resolved spectra when the CCD is operated in the full vertical binning mode. It is usually operated at 5 ms per frame. If the vertical size of the CCD is reduced with a narrow slit, the time response becomes faster. The high-time response in the spectral measurement therefore makes possible a variety of spectroscopic studies, e.g., impurity behavior in long pulse discharges with edge-localized mode bursts. An absolute intensity calibration of the EUV spectrometer is also carried out with a technique using the EUV bremsstrahlung continuum at 20-150 Å for quantitative data analysis. Thus, the high-time resolution tungsten spectra have been successfully observed with good spectral resolution using the present EUV spectrometer system. Typical tungsten spectra in the EUV wavelength range observed from EAST discharges are presented with absolute intensity and spectral identification.

  16. A fast-time-response extreme ultraviolet spectrometer for measurement of impurity line emissions in the Experimental Advanced Superconducting Tokamak.

    PubMed

    Zhang, Ling; Morita, Shigeru; Xu, Zong; Wu, Zhenwei; Zhang, Pengfei; Wu, Chengrui; Gao, Wei; Ohishi, Tetsutarou; Goto, Motoshi; Shen, Junsong; Chen, Yingjie; Liu, Xiang; Wang, Yumin; Dong, Chunfeng; Zhang, Hongmin; Huang, Xianli; Gong, Xianzu; Hu, Liqun; Chen, Junlin; Zhang, Xiaodong; Wan, Baonian; Li, Jiangang

    2015-12-01

    A flat-field extreme ultraviolet (EUV) spectrometer working in the 20-500 Å wavelength range with fast time response has been newly developed to measure line emissions from highly ionized tungsten in the Experimental Advanced Superconducting Tokamak (EAST) with a tungsten divertor, while the monitoring of light and medium impurities is also an aim in the present development. A flat-field focal plane for spectral image detection is made by a laminar-type varied-line-spacing concave holographic grating with an angle of incidence of 87°. A back-illuminated charge-coupled device (CCD) with a total size of 26.6 × 6.6 mm(2) and pixel numbers of 1024 × 255 (26 × 26 μm(2)/pixel) is used for recording the focal image of spectral lines. An excellent spectral resolution of Δλ0 = 3-4 pixels, where Δλ0 is defined as full width at the foot position of a spectral line, is obtained at the 80-400 Å wavelength range after careful adjustment of the grating and CCD positions. The high signal readout rate of the CCD can improve the temporal resolution of time-resolved spectra when the CCD is operated in the full vertical binning mode. It is usually operated at 5 ms per frame. If the vertical size of the CCD is reduced with a narrow slit, the time response becomes faster. The high-time response in the spectral measurement therefore makes possible a variety of spectroscopic studies, e.g., impurity behavior in long pulse discharges with edge-localized mode bursts. An absolute intensity calibration of the EUV spectrometer is also carried out with a technique using the EUV bremsstrahlung continuum at 20-150 Å for quantitative data analysis. Thus, the high-time resolution tungsten spectra have been successfully observed with good spectral resolution using the present EUV spectrometer system. Typical tungsten spectra in the EUV wavelength range observed from EAST discharges are presented with absolute intensity and spectral identification.

  17. AlGaN-on-Si backside illuminated photodetectors for the extreme ultraviolet (EUV) range

    NASA Astrophysics Data System (ADS)

    Malinowski, P. E.; Duboz, J.-Y.; John, J.; Sturdevant, C.; Das, J.; Derluyn, J.; Germain, M.; de Moor, P.; Minoglou, K.; Semond, F.; Frayssinet, E.; Hochedez, J.-F.; Giordanengo, B.; van Hoof, C.; Mertens, R.

    2010-04-01

    We report on the fabrication and characterization of solar blind Metal-Semiconductor-Metal (MSM) based photodetectors for use in the extreme ultraviolet (EUV) wavelength range. The devices were fabricated in the AlGaN-on- Si material system, with Aluminum Gallium Nitride (AlGaN) epitaxial layers grown on Si(111) by means of Molecular Beam Epitaxy. The detectors' IV characteristics and photoresponse were measured between 200 and 400 nm. Spectral responsivity was calculated for comparison with the state-of-the-art ultraviolet photodetectors. It reaches the order of 0.1 A/W at the cut-off wavelength of 360 nm, for devices with Au fingers of 3 μm width and spacing of 3 μm. The rejection ratio of visible radiation (400 nm) was more than 3 orders of magnitude. In the additional post-processing step, the Si substrate was removed locally under the active area of the MSM photodetectors using SF6-based Reactive Ion Etching (RIE). In such scheme, the backside illumination is allowed and there is no shadowing of the active layer by the metal electrodes, which is advantageous for the EUV sensitivity. Completed devices were assembled and wire-bonded in customized TO-8 packages with an opening. The sensitivity at EUV was verified at the wavelengths of 30.4 and 58.4 nm using a He-based beamline. AlGaN photodetectors are a promising alternative for highly demanding applications such as space science or modern EUV lithography. The backside illumination approach is suited in particular for large, 2D focal plane arrays.

  18. THE HIGH-RESOLUTION EXTREME-ULTRAVIOLET SPECTRUM OF N{sub 2} BY ELECTRON IMPACT

    SciTech Connect

    Heays, A. N.; Ajello, J. M.; Aguilar, A.; Lewis, B. R.; Gibson, S. T.

    2014-04-01

    We have analyzed high-resolution (FWHM = 0.2 Å) extreme-ultraviolet (EUV, 800-1350 Å) laboratory emission spectra of molecular nitrogen excited by an electron impact at 20 and 100 eV under (mostly) optically thin, single-scattering experimental conditions. A total of 491 emission features were observed from N{sub 2} electronic-vibrational transitions and atomic N I and N II multiplets and their emission cross sections were measured. Molecular emission was observed at vibrationally excited ground-state levels as high as v'' = 17, from the a {sup 1}Π {sub g} , b {sup 1}Π {sub u} , and b'{sup 1}Σ {sub u} {sup +} excited valence states and the Rydberg series c'{sub n} {sub +1} {sup 1}Σ {sub u} {sup +}, c{sub n} {sup 1}Π {sub u} , and o{sub n} {sup 1}Π {sub u} for n between 3 and 9. The frequently blended molecular emission bands were disentangled with the aid of a sophisticated and predictive quantum-mechanical model of excited states that includes the strong coupling between valence and Rydberg electronic states and the effects of predissociation. Improved model parameters describing electronic transition moments were obtained from the experiment and allowed for a reliable prediction of the vibrationally summed electronic emission cross section, including an extrapolation to unobserved emission bands and those that are optically thick in the experimental spectra. Vibrationally dependent electronic excitation functions were inferred from a comparison of emission features following 20 and 100 eV electron-impact collisional excitation. The electron-impact-induced fluorescence measurements are compared with Cassini Ultraviolet Imaging Spectrograph observations of emissions from Titan's upper atmosphere.

  19. The Limb-Imaging Ionospheric and Thermospheric Extreme-Ultraviolet Spectrograph (LITES) on the ISS

    NASA Astrophysics Data System (ADS)

    Stephan, Andrew W.; Finn, Susanna C.; Cook, Timothy A.; Chakrabarti, Supriya; Budzien, Scott A.

    2015-04-01

    The Limb-imaging Ionospheric and Thermospheric Extreme-ultraviolet Spectrograph (LITES) is being prepared for flight in early 2016 aboard the Space Test Program Houston 5 (STP-H5) experiment pallet to the International Space Station (ISS). LITES is an imaging spectrograph that spans 60-140 nm and will obtain limb profiles of the ionosphere, along with the key upper atmospheric constituents O and N2. During the day, LITES measures the OII 83.4 and 61.7 nm emissions that are produced by solar photoionization of atomic oxygen in the lower thermosphere. The 83.4 nm emission is resonantly scattered by ionospheric O+, and thus its altitude profile is formed by both the initial ionization brightness and the ionospheric content. The 61.7 nm emission is not scattered and is used to constrain the photoionization brightness in the retrieval. At night, recombination of O+ and electrons produces optically thin emissions at 91.1 and 135.6 nm that are used to tomographically reconstruct the two-dimensional ionosphere in the orbital plane.These observations will be complemented and validated by ground-based data from an international network of digisondes, visible spectrographs, and imagers, which will provide ground truth for the space-based measurements. Additionally, the STP-H5 mission includes the GPS Radio Occultation and Ultraviolet Photometer Co-located (GROUP-C) experiment that consists of a high-sensitivity, nadir-viewing photometer that measures the nighttime ionospheric airglow at 135.6 nm, and a GPS receiver that measures ionospheric electron content and scintillation. We will discuss the LITES measurements and science goals, and how LITES data will be combined with these other experiments to study low and middle latitude ionospheric structures on a global scale.

  20. First results of measurements of extreme ultraviolet radiation onboard a geostationary satellite "ELECTRO-L"

    NASA Astrophysics Data System (ADS)

    Nusinov, Anatoliy; Kazachevskaya, Tamara; Gonjukh, David

    Measurements of the intensity of EUV emission in the hydrogen Lyman-alpha line were conducted by a broadband photometer VUSS-E onboard geostationary Hydrometeorological satellite "Electro" since March 2011. The solar hydrogen Lyman-alpha line (lambda = 121.6 nm) was monitored. The photomultiplier with LiF window used as a detector insensitive to visible light. Long-wavelength limit of the spectral band sensitivity of the instrument is about 200 nm, so the signal of the device is defined as the flux of solar radiation in the region of 123-200 nm. Its exclusion was carried out by calculation. Since the satellite "Electro" designed for remote sensing of the Earth, its line of sight focused on Earth. Alignment of instrument in the Sun direction was achieved by installing it on the solar panel, periodically moved in the solar direction. Correction of instrument readings, reduced due to the deviation of its axis from the Sun direction, carried out by calculation. Measurements were carried out every second. The first results of the measurements are presented. The difference in absolute calibration Electro-L/VUSS-E is within 5% of corresponding values for measurements TIMED satellite in those days, that is in agreement with laboratory calibrations. It is useful to measure the temperature of the instrument, as its variation on a small interval of time makes change the value of the output signal about 1-2 %. During first year of operation, the sensitivity of the apparatus remained within ± 2% of measured value, significant degradation of sensitivity was not observed. Over time of observation there have been several large flares of X class. The increase of the signal in the ultraviolet range does not exceed a few percent during these flares.

  1. Surface phenomena related to mirror degradation in extreme ultraviolet (EUV) lithography

    NASA Astrophysics Data System (ADS)

    Madey, Theodore E.; Faradzhev, Nadir S.; Yakshinskiy, Boris V.; Edwards, N. V.

    2006-12-01

    One of the most promising methods for next generation device manufacturing is extreme ultraviolet (EUV) lithography, which uses 13.5 nm wavelength radiation generated from freestanding plasma-based sources. The short wavelength of the incident illumination allows for a considerable decrease in printed feature size, but also creates a range of technological challenges not present for traditional optical lithography. Contamination and oxidation form on multilayer reflecting optics surfaces that not only reduce system throughput because of the associated reduction in EUV reflectivity, but also introduce wavefront aberrations that compromise the ability to print uniform features. Capping layers of ruthenium, films ˜2 nm thick, are found to extend the lifetime of Mo/Si multilayer mirrors used in EUV lithography applications. However, reflectivities of even the Ru-coated mirrors degrade in time during exposure to EUV radiation. Ruthenium surfaces are chemically reactive and are very effective as heterogeneous catalysts. In the present paper we summarize the thermal and radiation-induced surface chemistry of bare Ru exposed to gases; the emphasis is on H 2O vapor, a dominant background gas in vacuum processing chambers. Our goal is to provide insights into the fundamental physical processes that affect the reflectivity of Ru-coated Mo/Si multilayer mirrors exposed to EUV radiation. Our ultimate goal is to identify and recommend practices or antidotes that may extend mirror lifetimes.

  2. THE EXTREME ULTRAVIOLET DEFICIT AND MAGNETICALLY ARRESTED ACCRETION IN RADIO-LOUD QUASARS

    SciTech Connect

    Punsly, Brian

    2014-12-20

    The Hubble Space Telescope composite quasar spectra presented in Telfer et al. show a significant deficit of emission in the extreme ultraviolet for the radio-loud component of the quasar population (RLQs) compared to the radio-quiet component of the quasar population. The composite quasar continuum emission between 1100 Å and ∼580 Å is generally considered to be associated with the innermost regions of the accretion flow onto the central black hole. The deficit between 1100 Å and 580 Å in RLQs has a straightforward interpretation as a missing or a suppressed innermost region of local energy dissipation in the accretion flow. It is proposed that this can be the result of islands of large-scale magnetic flux in RLQs that are located close to the central black hole that remove energy from the accretion flow as Poynting flux (sometimes called magnetically arrested accretion). These magnetic islands are natural sites for launching relativistic jets. Based on the Telfer et al. data and the numerical simulations of accretion flows in Penna et al., the magnetic islands are concentrated between the event horizon and an outer boundary of <2.8 M (in geometrized units) for rapidly rotating black holes and <5.5 M for modestly rotating black holes.

  3. A study of the mechanical vibrations of a table-top extreme ultraviolet interference nanolithography tool.

    PubMed

    Prezioso, S; De Marco, P; Zuppella, P; Santucci, S; Ottaviano, L

    2010-04-01

    A prototype low cost table-top extreme ultraviolet (EUV) laser source (1.5 ns pulse duration, lambda=46.9 nm) was successfully employed as a laboratory scale interference nanolithography (INL) tool. Interference patterns were obtained with a simple Lloyd's mirror setup. Periodic structures on Polymethylmethacrylate/Si substrates were produced on large areas (8 mm(2)) with resolutions from 400 to 22.5 nm half pitch (the smallest resolution achieved so far with table-top EUV laser sources). The mechanical vibrations affecting both the laser source and Lloyd's setup were studied to determine if and how they affect the lateral resolution of the lithographic system. The vibration dynamics was described by a statistical model based on the assumption that the instantaneous position of the vibrating mechanical parts follows a normal distribution. An algorithm was developed to simulate the process of sample irradiation under different vibrations. The comparison between simulations and experiments allowed to estimate the characteristic amplitude of vibrations that was deduced to be lower than 50 nm. The same algorithm was used to reproduce the expected pattern profiles in the lambda/4 half pitch physical resolution limit. In that limit, a nonzero pattern modulation amplitude was obtained from the simulations, comparable to the peak-to-valley height (2-3 nm) measured for the 45 nm spaced fringes, indicating that the mechanical vibrations affecting the INL tool do not represent a limit in scaling down the resolution.

  4. Extreme ultraviolet diagnostic upgrades for kink mode control on the HBT-EP tokamak

    NASA Astrophysics Data System (ADS)

    Levesque, J. P.; Brooks, J. W.; Desanto, S.; Mauel, M. E.; Navratil, G. A.; Page, J. W.; Hansen, C. J.; Delgado-Aparicio, L.

    2016-10-01

    Optical diagnostics can provide non-invasive measurements of tokamak equilibria and the internal characteristics of MHD mode activity. We present research plans and ongoing progress on upgrading extreme ultraviolet (EUV) diagnostics in the HBT-EP tokamak. Four sets of 16 poloidal views will allow tomographic reconstruction of plasma emissivity and internal kink mode structure. Emission characteristics of naturally-occurring m/n = 2/1, 3/2, and 3/1 tearing and kink modes will be compared with expectations from a synthetic diagnostic. Coupling between internal and external modes leading up to disruptions is studied. The internal plasma response to external magnetic perturbations is investigated, and compared with magnetic response measurements. Correlation between internal emissivity and external magnetic measurements provides a global picture of long-wavelength MHD instabilities. Measurements are input to HBT-EP's GPU-based feedback system, allowing active feedback for kink modes using only optical sensors and both magnetic and edge current actuators. A separate two-color, 16-chord tangential system will be installed next year to allow reconstruction of temperature profiles and their fluctuations versus time. Supported by U.S. DOE Grant DE-FG02-86ER53222.

  5. Characterization of an expanded-field Schwarzschild objective for extreme ultraviolet lithography

    SciTech Connect

    Kubiak, G.D.; Tichenor, D.A.; Ray-Chaudhuri, A.K.

    1994-08-01

    The performance of a new 10x-reduction Schwarzschild system for projection imaging at 13.4 nm wavelength is reported. The optical design is optimized to achieve 0.1 {mu}m resolution over a 0.4 mm image field of view, an increase in area of a factor of 100 over previous designs. An off-set aperture, located on the convex primary, defines an unobscured 0.08 numerical aperture. The system is illuminated using extreme ultraviolet (EUV) radiation emitted from a laser plasma source and collected by an ellipsoidal condenser. A 450 turning mirror is used to relay the collected EUV radiation onto a near-normal reflecting mask. Multiple sets of primary and secondary elements were fabricated, matched and clocked to minimize the effects of small figure errors on imaging performance. Optical metrology indicates that the wave-front error within the subaperture used is within a factor of two of the design value. Images recorded in PMMA and ZEP 520 resists reveal good imaging fidelity over much of the 0.4 mm field with equal line/space gratings being resolved to 0.1 {mu}m.

  6. Simulation of particle velocity in a laser-produced tin plasma extreme ultraviolet source

    SciTech Connect

    Masnavi, Majid; Nakajima, Mitsuo; Horioka, Kazuhiko; Araghy, Homaira Parchamy; Endo, Akira

    2011-06-15

    In connection with fast heating in a laser produced plasma (LPP) extreme ultraviolet (EUV) source, the superheating behavior of bulk tin (Sn) at high heating rates is investigated. A constant temperature and pressure molecular dynamics simulation using modified Lennard-Jones and Coulomb potentials suitable for studying the liquid structure of Sn is employed in order to derive the caloric curves of the solid and liquid phases. The results have shown transient effects on the phase transitions. Superheating is observed during the melting and vaporizing processes. The velocity distribution of Sn particles against typical laser fluence in a LPP EUV light source has been numerically investigated using a simplified method including a one-dimensional, two-temperature, molecular dynamics, and steady-state ionization model. In the framework of our model, it was found that ejected Sn particles have a maximum velocity on the order of 10 to 40 km/s in plasma created using a nanosecond pre-pulse neodymium-doped yttrium aluminum garnet (Nd:YAG, 1.06 {mu}m) laser in EUV lithography experiments.

  7. Visualizing the local optical response to extreme-ultraviolet radiation with a resolution of λ/380

    NASA Astrophysics Data System (ADS)

    Tamasaku, Kenji; Sawada, Kei; Nishibori, Eiji; Ishikawa, Tetsuya

    2011-09-01

    Scientists have continually tried to improve the spatial resolution of imaging ever since the invention of the optical microscope in around 1610 by Galileo. Recently, a spatial resolution near λ/10 was achieved in a near-field scheme by using surface plasmon polaritons. However, further improvement in this direction is hindered by the size of metallic nanostructures. Here we show that atom-scale resolution is achievable in the extreme-ultraviolet region by using X-ray parametric down-conversion, which detaches the achievable resolution from the wavelength of the probe light. We visualize three-dimensionally the local optical response of diamond at wavelengths between 103 and 206Å with a resolution as fine as 0.54Å. This corresponds to a resolution from λ/190 to λ/380, an order of magnitude better than ever achieved. Although the present study focuses on the relatively high-energy optical regions, our method could be extended into the visible region using advanced X-ray sources, and would open a new window into the optical properties of solids.

  8. Emulation of anamorphic imaging on the SHARP extreme ultraviolet mask microscope

    NASA Astrophysics Data System (ADS)

    Benk, Markus P.; Wojdyla, Antoine; Chao, Weilun; Salmassi, Farhad; Oh, Sharon; Wang, Yow-Gwo; Miyakawa, Ryan H.; Naulleau, Patrick P.; Goldberg, Kenneth A.

    2016-07-01

    The SHARP high-numerical aperture actinic reticle review project is a synchrotron-based, extreme ultraviolet (EUV) microscope dedicated to photomask research. SHARP emulates the illumination and imaging conditions of current EUV lithography scanners and those several generations into the future. An anamorphic imaging optic with increased mask-side numerical aperture (NA) in the horizontal and increased demagnification in the vertical direction has been proposed to overcome limitations of current multilayer coatings and extend EUV lithography beyond 0.33 NA. Zoneplate lenses with an anamorphic 4×/8× NA of 0.55 are fabricated and installed in the SHARP microscope to emulate anamorphic imaging. SHARP's Fourier synthesis illuminator with a range of angles exceeding the collected solid angle of the newly designed elliptical zoneplates can produce arbitrary angular source spectra matched to anamorphic imaging. A target with anamorphic dense features down to 50-nm critical dimension is fabricated using 40 nm of nickel as the absorber. In a demonstration experiment, anamorphic imaging at 0.55 4×/8× NA and 6 deg central ray angle (CRA) is compared with conventional imaging at 0.5 4× NA and 8 deg CRA. A significant contrast loss in horizontal features is observed in the conventional images. The anamorphic images show the same image quality in the horizontal and vertical directions.

  9. Extreme ultraviolet spectroscopy and modeling of Cu on the SSPX Spheromak and laser plasma 'Sparky'

    SciTech Connect

    Weller, M. E.; Safronova, A. S.; Kantsyrev, V. L.; Safronova, U. I.; Petkov, E. E.; Wilcox, P. G.; Osborne, G. C.; Clementson, J.; Beiersdorfer, P.

    2012-10-15

    Impurities play a critical role in magnetic fusion research. In large quantities, impurities can cool and dilute plasma creating problems for achieving ignition and burn; however in smaller amounts the impurities could provide valuable information about several plasma parameters through the use of spectroscopy. Many impurity ions radiate within the extreme ultraviolet (EUV) range. Here, we report on spectra from the silver flat field spectrometer, which was implemented at the Sustained Spheromak Physics experiment (SSPX) to monitor ion impurity emissions. The chamber within the SSPX was made of Cu, which makes M-shell Cu a prominent impurity signature. The Spect3D spectral analysis code was utilized to identify spectral features in the range of 115-315 A and to more fully understand the plasma conditions. A second set of experiments was carried out on the compact laser-plasma x-ray/EUV facility 'Sparky' at UNR, with Cu flat targets used. The EUV spectra were recorded between 40-300 A and compared with results from SSPX.

  10. Optical proximity correction for extreme ultra-violet mask with pellicle

    NASA Astrophysics Data System (ADS)

    Mo, Soo-Yeon; Kim, In-Seon; Oh, Hye-Keun

    2015-10-01

    Extreme ultraviolet (EUV) lithography is considered as one of the viable solutions for production of the next generation integrated devices. EUV mask defect control becomes more critical issue in order to sustain the quality of wafer fabrication process. Since pellicle is the essential component to prevent patterning deformations caused by particle defects on EUV mask[1-2], EUV OPC (optical proximity correction) that takes into account for pellicle effects on imaging quality is required for achieving better pattern fidelity and critical dimension control. In this study, image blurring effect induced by the EUV mask pellicle on mask pattern structures was investigated and it was found that the localized short-range OPC using commercial software performed as desired considering transmission intensity loss due to pellicle. For experiment, edge placement error differences of the same 2D logic patterns with 16 nm half pitch with and without pellicle were compared. Finally, a method was suggested how patterning throughput loss caused by the transmission loss can be compensated by EUV OPC, which may allow pellicle transmission even below 90%.

  11. Active Region Moss: Doppler Shifts from Hinode/Extreme-ultraviolet Imaging Spectrometer Observations

    NASA Astrophysics Data System (ADS)

    Tripathi, Durgesh; Mason, Helen E.; Klimchuk, James A.

    2012-07-01

    Studying the Doppler shifts and the temperature dependence of Doppler shifts in moss regions can help us understand the heating processes in the core of the active regions. In this paper, we have used an active region observation recorded by the Extreme-ultraviolet Imaging Spectrometer (EIS) on board Hinode on 2007 December 12 to measure the Doppler shifts in the moss regions. We have distinguished the moss regions from the rest of the active region by defining a low-density cutoff as derived by Tripathi et al. in 2010. We have carried out a very careful analysis of the EIS wavelength calibration based on the method described by Young et al. in 2012. For spectral lines having maximum sensitivity between log T = 5.85 and log T = 6.25 K, we find that the velocity distribution peaks at around 0 km s-1 with an estimated error of 4-5 km s-1. The width of the distribution decreases with temperature. The mean of the distribution shows a blueshift which increases with increasing temperature and the distribution also shows asymmetries toward blueshift. Comparing these results with observables predicted from different coronal heating models, we find that these results are consistent with both steady and impulsive heating scenarios. However, the fact that there are a significant number of pixels showing velocity amplitudes that exceed the uncertainty of 5 km s-1 is suggestive of impulsive heating. Clearly, further observational constraints are needed to distinguish between these two heating scenarios.

  12. Analysis and control of thin film stresses during extreme ultraviolet lithography mask blank fabrication

    NASA Astrophysics Data System (ADS)

    Zheng, Liang

    2010-11-01

    Extreme Ultraviolet Lithography (EUVL) is the leading candidate for Next-Generation Lithography (NGL) in the sub-45 nm regime. One of the critical technical problems to be solved before the commercialization of EUVL is the control of image placement errors during EUVL mask blank fabrication. This paper focuses on the characterization of image placement errors induced by the thin film stresses during EUVL mask blank fabrication. Firstly, the causes and classifications of the stresses in the thin films were discussed. Then an analytical analysis was developed to reveal the effects of the thin film stresses on the distortions of the EUVL mask. Lastly, finite element (FE) models were established to simulate each process step in EUVL mask blank fabrication. The out-of-plane distortions (OPD) and inplane distortions (IPD) were tracked for each process step. The numerical results are compared with the analytical results to validate the FE models. Comparison indicated that numerical results and theoretical results agree very well with each other. The research in this paper provides a solid support for EUVL mask blank fabrication, theoretically and numerically. Further mounting and chucking procedures can keep image placement errors within the allotted error budget as well as provide the necessary flatness.

  13. Extreme ultraviolet imaging of three-dimensional magnetic reconnection in a solar eruption

    PubMed Central

    Sun, J. Q.; Cheng, X.; Ding, M. D.; Guo, Y.; Priest, E. R.; Parnell, C. E.; Edwards, S. J.; Zhang, J.; Chen, P. F.; Fang, C.

    2015-01-01

    Magnetic reconnection, a change of magnetic field connectivity, is a fundamental physical process in which magnetic energy is released explosively, and it is responsible for various eruptive phenomena in the universe. However, this process is difficult to observe directly. Here, the magnetic topology associated with a solar reconnection event is studied in three dimensions using the combined perspectives of two spacecraft. The sequence of extreme ultraviolet images clearly shows that two groups of oppositely directed and non-coplanar magnetic loops gradually approach each other, forming a separator or quasi-separator and then reconnecting. The plasma near the reconnection site is subsequently heated from ∼1 to ≥5 MK. Shortly afterwards, warm flare loops (∼3 MK) appear underneath the hot plasma. Other observational signatures of reconnection, including plasma inflows and downflows, are unambiguously revealed and quantitatively measured. These observations provide direct evidence of magnetic reconnection in a three-dimensional configuration and reveal its origin. PMID:26113464

  14. Laser-assisted vacuum arc extreme ultraviolet source: a comparison of picosecond and nanosecond laser triggering

    NASA Astrophysics Data System (ADS)

    Beyene, Girum A.; Tobin, Isaac; Juschkin, Larissa; Hayden, Patrick; O'Sullivan, Gerry; Sokell, Emma; Zakharov, Vassily S.; Zakharov, Sergey V.; O'Reilly, Fergal

    2016-06-01

    Extreme ultraviolet (EUV) light generation by hybrid laser-assisted vacuum arc discharge plasmas, utilizing Sn-coated rotating-disc-electrodes, was investigated. The discharge was initiated by localized ablation of the liquid tin coating of the cathode disc by a laser pulse. The laser pulse, at 1064 nm, was generated by Nd:YAG lasers with variable energy from 1 to 100 mJ per pulse. The impact of shortening the laser pulse from 7 ns to 170 ps on the EUV generation has been investigated in detail. The use of ps pulses resulted in an increase in emission of EUV radiation. With a fixed discharge energy of ~4 J, the EUV conversion efficiency tends to plateau at ~2.4  ±  0.25% for the ps laser pulses, while for the ns pulses, it saturates at ~1.7  ±  0.3%. Under similar discharge and laser energy conditions, operating the EUV source with the ps-triggering resulted also in narrower spectral profiles of the emission in comparison to ns-triggering. The results indicate an advantage in using ps-triggering in laser-assisted discharges to produce brighter plasmas required for applications such as metrology.

  15. Stable droplet generator for a high brightness laser produced plasma extreme ultraviolet source

    NASA Astrophysics Data System (ADS)

    Vinokhodov, A.; Krivokorytov, M.; Sidelnikov, Yu.; Krivtsun, V.; Medvedev, V.; Bushuev, V.; Koshelev, K.; Glushkov, D.; Ellwi, S.

    2016-10-01

    We present the results of the low-melting liquid metal droplets generation based on excited Rayleigh jet breakup. We discuss on the operation of the industrial and in-house designed and manufactured dispensing devices for the droplets generation. Droplet diameter can be varied in the range of 30-90 μm. The working frequency of the droplets, velocity, and the operating temperature were in the ranges of 20-150 kHz, 4-15 m/s, and up to 250 °C, respectively. The standard deviations for the droplet center of mass position both their diameter σ < 1 μm at the distance of 45 mm from the nozzle. Stable operation in the long-term (over 1.5 h) was demonstrated for a wide range of the droplet parameters: diameters, frequencies, and velocities. Physical factors affecting the stability of the generator operation have been identified. The technique for droplet synchronization, allowing using the droplet as a target for laser produced plasma, has been created; in particular, the generator has been successfully used in a high brightness extreme ultraviolet (EUV) light source. The operation with frequency up to 8 kHz was demonstrated as a result of the experimental simulation, which can provide an average brightness of the EUV source up to ˜1.2 kW/mm2 sr.

  16. Incident angle change caused by different off-axis illumination in extreme ultraviolet lithography

    NASA Astrophysics Data System (ADS)

    Kim, Eun-Jin; You, Jee-Hye; Kim, Seong-Sue; Cho, Han-Ku; An, Ilsin; Oh, Hye-Keun

    2009-03-01

    Extreme ultraviolet lithography (EUVL) is believed to be possible patterning technology which can make 22 nm and below. EUV uses a reflective mask so that the mask is shined with the oblique incident light. Thus, the study of incident angle effect is very important. Currently, 6 degree oblique incidence is main stream, but 5 degree incident angle is also studied for 0.25 NA. Incident angles larger than 6 degree are also considered for larger NA. This incident angle will affect many things, eventually to the line width. Shadow effect also strongly depends on the incident angle. This shadow effect in the EUVL mask is an important factor that decreases the contrast of the aerial image and causes a directional problem, thus it will make line width variation. The off-axis illumination (OAI) will be used with conventional on-axis illumination to make much smaller patterns. This OAI will split the main beam and change the incident angle. We found that if the incident angle increased with higher degree of coherence, the aerial image went worse. The CD difference between the horizontal and the vertical pattern is also dependent on the degree of coherence even though it is small.

  17. On the Importance of the Flare's Late Phase for the Solar Extreme Ultraviolet Irradiance

    NASA Technical Reports Server (NTRS)

    Woods, Thomas N.; Eparvier, Frank; Jones, Andrew R.; Hock, Rachel; Chamberlin, Phillip C.; Klimchuk, James A.; Didkovsky, Leonid; Judge, Darrell; Mariska, John; Bailey, Scott; Tobiska, W. Kent; Schrijver, Carolus J.; Webb, David F.; Warren, Harry

    2011-01-01

    The new solar extreme ultraviolet (EUV) irradiance observations from NASA Solar Dynamics Observatory (SDO) have revealed a new class of solar flares that are referred to as late phase flares. These flares are characterized by the hot 2-5 MK coronal emissions (e.g., Fe XVI 33.5 nm) showing large secondary peaks that appear many minutes to hours after an eruptive flare event. In contrast, the cool 0.7-1.5 MK coronal emissions (e.g., Fe IX 17.1 nm) usually dim immediately after the flare onset and do not recover until after the delayed second peak of the hot coronal emissions. We refer to this period of 1-5 hours after the fl amrea sin phase as the late phase, and this late phase is uniquely different than long duration flares associated with 2-ribbon flares or large filament eruptions. Our analysis of the late phase flare events indicates that the late phase involves hot coronal loops near the flaring region, not directly related to the original flaring loop system but rather with the higher post-eruption fields. Another finding is that space weather applications concerning Earth s ionosphere and thermosphere need to consider these late phase flares because they can enhance the total EUV irradiance flare variation by a factor of 2 when the late phase contribution is included.

  18. Imaging extreme ultraviolet spectrometer employing a single toroidal diffraction grating: the initial evaluation.

    PubMed

    Huber, M C; Timothy, J G; Morgan, J S; Lemaitre, G; Tondello, G; Jannitti, E; Scarin, P

    1988-08-15

    A high-efficiency extreme ultraviolet (EUV) imaging spectrometer has been constructed and tested. The spectrometer employs a concave toroidal grating illuminated at normal incidence in a Rowland circle mounting and has only one reflecting surface. The toroidal grating has been fabricated by a new technique employing an elastically deformable submaster grating which is replicated in a spherical form and then mechanically distorted to produce the desired aspect ratio of the toroidal surface for stigmatic imaging over the selected wavelength range. The fixed toroidal grating used in the spectrometer is then replicated from this surface. Photographic tests and initial photoelectric tests with a 2-D pulse-counting detector system have verified the image quality of the toroidal grating at wavelengths near 600 A. The results of these initial tests are described in detail, and the basic designs of two instruments which could employ the imaging spectrometer for astrophysical investigations in space are briefly described, namely, a high-resolution EUV spectroheliometer for studies of the solar chromosphere, transition region, and corona and an EUV spectroscopic telescope for studies of nonsolar objects.

  19. Technique for rapid at-wavelength inspection of extreme ultraviolet mask blanks

    SciTech Connect

    Spector, S. J.; White, D. L.; Tennant, D. M.; Ocola, L. E.; Novembre, A. E.; Peabody, M. L.; Wood, O. R. II

    1999-11-01

    We have developed two new methods for at-wavelength inspection of mask blanks for extreme-ultraviolet (EUV) lithography. In one method an EUV photoresist is applied directly to a mask blank which is then flood exposed with EUV light and partially developed. In the second method, the photoresist is applied to an EUV transparent membrane that is placed in close proximity to the mask and then exposed and developed. Both reflectivity defects and phase defects alter the exposure of the resist, resulting in mounds of resist at defect sites that can then be located by visual inspection. In the direct application method, a higher contrast resist was shown to increase the height of the mounds, thereby improving the sensitivity of the technique. In the membrane method, a holographic technique was used to reconstruct an image of the mask, revealing the presence of very small defects, approximately 0.2 {mu}m in size. The demonstrated clean transfer of phase and amplitude defects to resist features on a membrane will be important when flagging defects in an automatic inspection tool. (c) 1999 American Vacuum Society.

  20. Droplet-based, high-brightness extreme ultraviolet laser plasma source for metrology

    NASA Astrophysics Data System (ADS)

    Vinokhodov, A. Yu.; Krivokorytov, M. S.; Sidelnikov, Yu. V.; Krivtsun, V. M.; Medvedev, V. V.; Koshelev, K. N.

    2016-10-01

    We report on the development of a high brightness source of extreme ultraviolet radiation (EUV) with a working wavelength of 13.5 nm. The source is based on a laser-produced plasma driven by pulsed radiation of a Nd:YAG laser system. Liquid droplets of Sn-In eutectic alloy were used as the source fuel. The droplets were created by a droplet generator operating in the jet break-up regime. The EUV emission properties of the plasma, including the emission spectrum, time profile, and conversion efficiency of laser radiation into useful 13.5 nm photons, have been characterized. Using the shadowgraphy technique, we demonstrated the production of corpuscular debris by the plasma source and the influence of the plasma on the neighboring droplet targets. The high-frequency laser operation was simulated by usage of the dual pulse regime. Based on the experimental results, we discuss the physical phenomena that could affect the source operation at high repetition rates. Finally, we estimate that an average source brightness of 1.2 kW/mm2 sr is feasible at a high repetition rate.

  1. STUDY OF SOLAR ENERGETIC PARTICLE ASSOCIATIONS WITH CORONAL EXTREME-ULTRAVIOLET WAVES

    SciTech Connect

    Park, Jinhye; Moon, Y.-J.; Innes, D. E.; Bucik, R.; Kahler, S. W.

    2015-07-20

    We study the relationship between large gradual solar energetic particle (SEP) events and associated extreme-ultraviolet (EUV) wave properties in 16 events that occurred between 2010 August and 2013 May and were observed by SDO, the Solar and Heliospheric Observatory (SOHO), and/or STEREO. We determine onset times, peak times, and peak fluxes of the SEP events in the SOHO/ERNE and STEREO/LET proton channels (6–10 MeV). The EUV wave arrival times and their speeds from the source sites to the spacecraft footpoints in the photosphere, which are magnetically connected to the spacecraft by Parker spiral and potential fields, are determined by spacetime plots from the full-Sun heliographic images created by combining STEREO-A and STEREO-B 195 Å and SDO 193 Å images. The SEP peak fluxes increase with the EUV wave speeds, and the SEP spectral indices become harder with the speeds. This shows that higher energetic particle fluxes are associated with faster EUV waves, which are considered as the lateral expansions of coronal-mass-ejection-driven shocks in the low corona.

  2. Extreme ultraviolet detection using AlGaN-on-Si inverted Schottky photodiodes

    NASA Astrophysics Data System (ADS)

    Malinowski, Pawel E.; Duboz, Jean-Yves; De Moor, Piet; Minoglou, Kyriaki; John, Joachim; Horcajo, Sara Martin; Semond, Fabrice; Frayssinet, Eric; Verhoeve, Peter; Esposito, Marco; Giordanengo, Boris; BenMoussa, Ali; Mertens, Robert; Van Hoof, Chris

    2011-04-01

    We report on the fabrication of aluminum gallium nitride (AlGaN) Schottky diodes for extreme ultraviolet (EUV) detection. AlGaN layers were grown on silicon wafers by molecular beam epitaxy with the conventional and inverted Schottky structure, where the undoped, active layer was grown before or after the n-doped layer, respectively. Different current mechanisms were observed in the two structures. The inverted Schottky diode was designed for the optimized backside sensitivity in the hybrid imagers. A cut-off wavelength of 280 nm was observed with three orders of magnitude intrinsic rejection ratio of the visible radiation. Furthermore, the inverted structure was characterized using a EUV source based on helium discharge and an open electrode design was used to improve the sensitivity. The characteristic He I and He II emission lines were observed at the wavelengths of 58.4 nm and 30.4 nm, respectively, proving the feasibility of using the inverted layer stack for EUV detection.

  3. CITIUS: An infrared-extreme ultraviolet light source for fundamental and applied ultrafast science

    SciTech Connect

    Grazioli, C.; Gauthier, D.; Ivanov, R.; De Ninno, G.; Callegari, C.; Spezzani, C.; Ciavardini, A.; Coreno, M.; Frassetto, F.; Miotti, P.; Poletto, L.; Golob, D.; Kivimäki, A.; Mahieu, B.; Bučar, B.; Merhar, M.; Polo, E.; Ressel, B.

    2014-02-15

    We present the main features of CITIUS, a new light source for ultrafast science, generating tunable, intense, femtosecond pulses in the spectral range from infrared to extreme ultraviolet (XUV). The XUV pulses (about 10{sup 5}-10{sup 8} photons/pulse in the range 14-80 eV) are produced by laser-induced high-order harmonic generation in gas. This radiation is monochromatized by a time-preserving monochromator, also allowing one to work with high-resolution bandwidth selection. The tunable IR-UV pulses (10{sup 12}-10{sup 15} photons/pulse in the range 0.4-5.6 eV) are generated by an optical parametric amplifier, which is driven by a fraction of the same laser pulse that generates high order harmonics. The IR-UV and XUV pulses follow different optical paths and are eventually recombined on the sample for pump-probe experiments. We also present the results of two pump-probe experiments: with the first one, we fully characterized the temporal duration of harmonic pulses in the time-preserving configuration; with the second one, we demonstrated the possibility of using CITIUS for selective investigation of the ultra-fast dynamics of different elements in a magnetic compound.

  4. CITIUS: an infrared-extreme ultraviolet light source for fundamental and applied ultrafast science.

    PubMed

    Grazioli, C; Callegari, C; Ciavardini, A; Coreno, M; Frassetto, F; Gauthier, D; Golob, D; Ivanov, R; Kivimäki, A; Mahieu, B; Bučar, B; Merhar, M; Miotti, P; Poletto, L; Polo, E; Ressel, B; Spezzani, C; De Ninno, G

    2014-02-01

    We present the main features of CITIUS, a new light source for ultrafast science, generating tunable, intense, femtosecond pulses in the spectral range from infrared to extreme ultraviolet (XUV). The XUV pulses (about 10(5)-10(8) photons/pulse in the range 14-80 eV) are produced by laser-induced high-order harmonic generation in gas. This radiation is monochromatized by a time-preserving monochromator, also allowing one to work with high-resolution bandwidth selection. The tunable IR-UV pulses (10(12)-10(15) photons/pulse in the range 0.4-5.6 eV) are generated by an optical parametric amplifier, which is driven by a fraction of the same laser pulse that generates high order harmonics. The IR-UV and XUV pulses follow different optical paths and are eventually recombined on the sample for pump-probe experiments. We also present the results of two pump-probe experiments: with the first one, we fully characterized the temporal duration of harmonic pulses in the time-preserving configuration; with the second one, we demonstrated the possibility of using CITIUS for selective investigation of the ultra-fast dynamics of different elements in a magnetic compound.

  5. Dynamic absorption coefficients of chemically amplified resists and nonchemically amplified resists at extreme ultraviolet

    NASA Astrophysics Data System (ADS)

    Fallica, Roberto; Stowers, Jason K.; Grenville, Andrew; Frommhold, Andreas; Robinson, Alex P. G.; Ekinci, Yasin

    2016-07-01

    The dynamic absorption coefficients of several chemically amplified resists (CAR) and non-CAR extreme ultraviolet (EUV) photoresists are measured experimentally using a specifically developed setup in transmission mode at the x-ray interference lithography beamline of the Swiss Light Source. The absorption coefficient α and the Dill parameters ABC were measured with unprecedented accuracy. In general, the α of resists match very closely with the theoretical value calculated from elemental densities and absorption coefficients, whereas exceptions are observed. In addition, through the direct measurements of the absorption coefficients and dose-to-clear values, we introduce a new figure of merit called chemical sensitivity to account for all the postabsorption chemical reaction ongoing in the resist, which also predicts a quantitative clearing volume and clearing radius, due to the photon absorption in the resist. These parameters may help provide deeper insight into the underlying mechanisms of the EUV concepts of clearing volume and clearing radius, which are then defined and quantitatively calculated.

  6. Spectroscopic study of debris mitigation with minimum-mass Sn laser plasma for extreme ultraviolet lithography

    SciTech Connect

    Namba, S.; Fujioka, S.; Nishimura, H.; Yasuda, Y.; Nagai, K.; Miyanaga, N.; Izawa, Y.; Mima, K.; Takiyama, K.

    2006-04-24

    An experimental study was made of a target consisting of the minimum mass of pure tin (Sn) necessary for the highest conversion to extreme ultraviolet (EUV) light while minimizing the generation of plasma debris. The minimum-mass target comprised a thin Sn layer coated on a plastic shell and was irradiated with a Nd:YAG laser pulse. The expansion behavior of neutral atoms and singly charged ions emanating from the Sn plasma were investigated by spatially resolved visible spectroscopy. A remarkable reduction of debris emission in the backward direction with respect to the incident laser beam was demonstrated with a decrease in the thickness of the Sn layer. The optimal thickness of the Sn layer for a laser pulse of 9 ns at 7x10{sup 10} W/cm{sup 2} was found to be 40 nm, at which low-debris emission in the backward direction and a high conversion to 13.5 nm EUV radiation were simultaneously attained.

  7. Diagnosis of energy transport in iron buried layer targets using an extreme ultraviolet laser

    NASA Astrophysics Data System (ADS)

    Shahzad, M.; Culfa, O.; Rossall, A. K.; Wilson, L. A.; Guilbaud, O.; Kazamias, S.; Delmas, O.; Demailly, J.; Maitrallain, A.; Pittman, M.; Baynard, E.; Farjardo, M.; Tallents, G. J.

    2015-02-01

    We demonstrate the use of extreme ultra-violet (EUV) laboratory lasers in probing energy transport in laser irradiated solid targets. EUV transmission through targets containing a thin layer of iron (50 nm) encased in plastic (CH) after irradiation by a short pulse (35 fs) laser focussed to irradiances 3 × 1016 Wcm-2 is measured. Heating of the iron layer gives rise to a rapid decrease in EUV opacity and an increase in the transmission of the 13.9 nm laser radiation as the iron ionizes to Fe5+ and above where the ion ionisation energy is greater than the EUV probe photon energy (89 eV). A one dimensional hydrodynamic fluid code HYADES has been used to simulate the temporal variation in EUV transmission (wavelength 13.9 nm) using IMP opacity values for the iron layer and the simulated transmissions are compared to measured transmission values. When a deliberate pre-pulse is used to preform an expanding plastic plasma, it is found that radiation is important in the heating of the iron layer while for pre-pulse free irradiation, radiation transport is not significant.

  8. A Model of Electronically-Excited States of N_2 and its Extreme-Ultraviolet Spectrum.

    NASA Astrophysics Data System (ADS)

    Heays, A. N.; Lewis, B. R.; Gibson, S. T.

    2013-06-01

    The nitrogen molecule is a long-studied and difficult problem in molecular spectroscopy, and many important details of its interaction with radiation remain unexplained. A principal problem of continuing interest concerns the resonant photoabsorption and resultant predissociation of N_2 when exposed to extreme-ultraviolet radiation. A model of the relevant excited states of N_2 has been developed in order to quantify their interactions and reproduce photoabsorption and photodissociation cross sections between 100 000 and 118 500 cm^{-1} (100 and 84 nm). This solves the radial Schrödinger equation within a coupled-channels formulation for new diabatic potential-energy curves, homogeneous and heterogeneous state mixing, and electronic transition moments for the optically allowed transitions. The accidental predissociation of {}^1Π_u states between 100 000 and 112 500 cm^{-1} has been quantitatively modelled by spin-orbit coupling these to a set of {}^3Π_u and {}^3Σ_u^+ states which includes unbound members. Following reference to a large experimental database, the model is both accurate and comprehensive and may be used to simulate synthetic cross sections for any temperature or isotopologue. These are suitable for use in high-resolution photochemical models of atmospheric and astrophysical environments.

  9. Extreme ultraviolet emission and confinement of tin plasmas in the presence of a magnetic field

    SciTech Connect

    Roy, Amitava E-mail: aroy@barc.gov.in; Murtaza Hassan, Syed; Harilal, Sivanandan S.; Hassanein, Ahmed; Endo, Akira; Mocek, Tomas

    2014-05-15

    We investigated the role of a guiding magnetic field on extreme ultraviolet (EUV) and ion emission from a laser produced Sn plasma for various laser pulse duration and intensity. For producing plasmas, planar slabs of pure Sn were irradiated with 1064 nm, Nd:YAG laser pulses with varying pulse duration (5–15 ns) and intensity. A magnetic trap was fabricated with the use of two neodymium permanent magnets which provided a magnetic field strength ∼0.5 T along the plume expansion direction. Our results indicate that the EUV conversion efficiency do not depend significantly on applied axial magnetic field. Faraday Cup ion analysis of Sn plasma show that the ion flux reduces by a factor of ∼5 with the application of an axial magnetic field. It was found that the plasma plume expand in the lateral direction with peak velocity measured to be ∼1.2 cm/μs and reduced to ∼0.75 cm/μs with the application of an axial magnetic field. The plume expansion features recorded using fast photography in the presence and absence of 0.5 T axial magnetic field are simulated using particle-in-cell code. Our simulation results qualitatively predict the plasma behavior.

  10. Low-line edge roughness extreme ultraviolet photoresists of organotin carboxylates

    NASA Astrophysics Data System (ADS)

    Del Re, Ryan; Passarelli, James; Sortland, Miriam; Cardineau, Brian; Ekinci, Yasin; Buitrago, Elizabeth; Neisser, Mark; Freedman, Daniel A.; Brainard, Robert L.

    2015-10-01

    Pure thin films of organotin compounds have been lithographically evaluated using extreme ultraviolet lithography (EUVL, 13.5 nm). Twenty compounds of the type R2Sn) were spin-coated from solutions in toluene, exposed to EUV light, and developed in organic solvents. Exposures produced negative-tone contrast curves and dense-line patterns using interference lithography. Contrast-curve studies indicated that the photosensitivity is linearly related to the molecular weight of the carboxylate group bound to tin. Additionally, photosensitivity was found to be linearly related to free radical stability of the hydrocarbon group bound directly to tin (R=phenyl, butyl, and benzyl). Dense-line patterning capabilities varied, but two resists in particular show exceptionally good line edge roughness (LER). A resist composed of an amorphous film of )SnCC)2 (1) achieved 1.4 nm LER at 22-nm half-pitch patterning and a resist composed of )Sn) (2) achieved 1.1 nm LER at 35-nm half-pitch at high exposure doses (600 mJ/cm2). Two photoresists that use olefin-based carboxylates, )SnCCH (3) and )SnCC (4), demonstrated better photospeeds (5 mJ/cm2 and 27 mJ/cm2) but worse LER.

  11. Lifetime studies of Mo/Si and Mo/Be multilayer coatings for extreme ultraviolet lithography

    NASA Astrophysics Data System (ADS)

    Wedowski, Marco; Bajt, Sasa; Folta, James A.; Gullikson, Eric M.; Kleineberg, Ulf; Klebanoff, Leonard E.; Malinowski, Michael E.; Clift, W. Miles

    1999-11-01

    Extreme Ultraviolet Lithography (EUVL) is a candidate for future application by the semiconductor industry in the production of sub-100 nm feature sizes in integrated circuits. Using multilayer reflective coatings optimized at wavelengths ranging from 11 to 14 nm, EUVL represents a potential successor to currently existing optical lithography techniques. In order to assess lifetimes of the multilayer coatings under realistic conditions, a series of radiation stability tests has been performed. In each run a dose of EUV radiation equivalent to several months of lithographic operation was applied to Mo/Si and Mo/Be multilayer coatings within a few days. Depending on the residual gas concentration in the vacuum environment, surface deposition of carbon during the exposure lead to losses in the multilayer reflectivity. However, in none of the experimental runs was structural damage within the bulk of the multilayers observed. Mo/Si multilayer coatings recovered their full original reflectivity after removal of the carbon layer by an ozone cleaning method. Auger depth profiling on Mo/Be multilayers indicate that carbon penetrated into the Be top layer during illumination with high doses of EUV radiation. Subsequent ozone cleaning fully removed the carbon, but revealed enhanced oxidation of the area illuminated, which led to an irreversible loss in reflectance on the order of 1%.

  12. Real-time and Sub-wavelength Ultrafast Coherent Diffraction Imaging in the Extreme Ultraviolet

    PubMed Central

    Zürch, M.; Rothhardt, J.; Hädrich, S.; Demmler, S.; Krebs, M.; Limpert, J.; Tünnermann, A.; Guggenmos, A.; Kleineberg, U.; Spielmann, C.

    2014-01-01

    Coherent Diffraction Imaging is a technique to study matter with nanometer-scale spatial resolution based on coherent illumination of the sample with hard X-ray, soft X-ray or extreme ultraviolet light delivered from synchrotrons or more recently X-ray Free-Electron Lasers. This robust technique simultaneously allows quantitative amplitude and phase contrast imaging. Laser-driven high harmonic generation XUV-sources allow table-top realizations. However, the low conversion efficiency of lab-based sources imposes either a large scale laser system or long exposure times, preventing many applications. Here we present a lensless imaging experiment combining a high numerical aperture (NA = 0.8) setup with a high average power fibre laser driven high harmonic source. The high flux and narrow-band harmonic line at 33.2 nm enables either sub-wavelength spatial resolution close to the Abbe limit (Δr = 0.8λ) for long exposure time, or sub-70 nm imaging in less than one second. The unprecedented high spatial resolution, compactness of the setup together with the real-time capability paves the way for a plethora of applications in fundamental and life sciences. PMID:25483626

  13. Control of coherent excitation of neon in the extreme ultraviolet regime.

    PubMed

    Plenge, Jürgen; Wirsing, Andreas; Raschpichler, Christopher; Wassermann, Bernhard; Rühl, Eckart

    2011-01-01

    Coherent excitation of a superposition of Rydberg states in neon by the 13th harmonic of an intense 804 nm pulse and the formation of a wave packet is reported. Pump-probe experiments are performed, where the 3d-manifold of the 2p6-->2p5 (2P3/2) 3d [1/2]1- and 2p6-->2p5 (2P3/2) 3d [3/2]1-transitions are excited by an extreme ultraviolet (XUV) radiation pulse, which is centered at 20.05 eV photon energy. The temporal evolution of the excited state population is probed by ionization with a time-delayed 804 nm pulse. Control of coherent transient excitation and wave packet dynamics in the XUV-regime is demonstrated, where the spectral phase of the 13th harmonic is used as a control parameter. Modulation of the phase is achieved by propagation of the XUV-pulse through neon of variable gas density. The experimental results indicate that phase-shaped high-order harmonics can be used to control fundamental coherent excitation processes in the XUV-regime.

  14. Characterization of material ablation driven by laser generated intense extreme ultraviolet light

    SciTech Connect

    Tanaka, Nozomi Masuda, Masaya; Deguchi, Ryo; Murakami, Masakatsu; Fujioka, Shinsuke; Yogo, Akifumi; Nishimura, Hiroaki; Sunahara, Atsushi

    2015-09-14

    We present a comparative study on the hydrodynamic behaviour of plasmas generated by material ablation by the irradiation of nanosecond extreme ultraviolet (EUV or XUV) or infrared laser pulses on solid samples. It was clarified that the difference in the photon energy deposition and following material heating mechanism between these two lights result in the difference in the plasma parameters and plasma expansion characteristics. Silicon plate was ablated by either focused intense EUV pulse (λ = 9–25 nm, 10 ns) or laser pulse (λ = 1064 nm, 10 ns), both with an intensity of ∼10{sup 9 }W/cm{sup 2}. Both the angular distributions and energy spectra of the expanding ions revealed that the photoionized plasma generated by the EUV light differs significantly from that produced by the laser. The laser-generated plasma undergoes spherical expansion, whereas the EUV-generated plasma undergoes planar expansion in a comparatively narrow angular range. It is presumed that the EUV radiation is transmitted through the expanding plasma and directly photoionizes the samples in the solid phase, consequently forming a high-density and high-pressure plasma. Due to a steep pressure gradient along the direction of the target normal, the EUV plasma expands straightforward resulting in the narrower angular distribution observed.

  15. Characterization of an expanded-field Schwarzschild objective for extreme ultraviolet lithography

    SciTech Connect

    Kubiak, G.D.; Tichenor, D.A.; Ray-Chaudhuri, A.K.; Malinowski, M.E.; Stulen, R.H.; Haney, S.J.; Berger, K.W.; Nissen, R.P.; Wilkerson, G.A.; Paul, P.H. ); Bjorkholm, J.E.; Fetter, L.A.; Freeman, R.R.; Himel, M.D.; MacDowell, A.A.; Tennant, D.M.; Wood, O.R. II ); Waskiewicz, W.K.; White, D.L.; Windt, D.L. ); Jewell, T.E. )

    1994-11-01

    The performance of a new 10[times]-reduction Schwarzschild system for projection imaging at 13.4 nm wavelength is reported. The optical design is optimized to achieve 0.1 [mu]m resolution over a 0.4 mm image field of view, an increase in area of a factor of 100 over previous designs. An offset aperture, located on the convex primary, defines an unobscured 0.08 numerical aperture. The system is illuminated using extreme ultraviolet (EUV) radiation emitted from a laser plasma source and collected by an ellipsoidal condenser. A 45[degree] turning mirror is used to relay the collected EUV radiation onto a near-normal reflecting mask. Multiple sets of primary and secondary elements were fabricated, matched, and clocked to minimize the effects of small figure errors on imaging performance. Optical metrology indicates that the wave-front error within the subaperture used is within a factor of 2 of the design value. Images recorded in poly(methyl methacrylate) and ZEP 520 (Nippon Zeon) resists reveal good imaging fidelity over much of the 0.4 mm field with equal line/space gratings being resolved to 0.1 [mu]m.

  16. Electron impact excitation collision strengths for extreme ultraviolet lines of Fe VII

    SciTech Connect

    Tayal, S. S.; Zatsarinny, O. E-mail: oleg.zatsarinny@drake.edu

    2014-06-10

    Extensive calculations have been performed for electron impact excitation collision strengths and oscillator strengths for the Fe VII extreme ultraviolet lines of astrophysical importance. The collision strengths for fine-structure transitions are calculated in the B-spline Breit-Pauli R-matrix approach. The target wavefunctions have been calculated in the multiconfiguration Hartree-Fock method with term-dependent non-orthogonal orbitals. The close-coupling expansion includes 189 fine-structure levels of Fe VII belonging to terms of the ground 3p {sup 6}3d {sup 2} and excited 3p {sup 5}3d {sup 3}, 3p {sup 6}3d4l, 3p {sup 6}3d5s, and 3p {sup 6}3d5p configurations. The effective collision strengths are determined from the electron excitation collision strengths by integration over a Maxwellian distribution of electron velocities. The effective collision strengths are provided for 17766 fine-structure transitions at electron temperatures from 10{sup 4} to 10{sup 7} K. Our results normally agree with the previous R-matrix frame-transformation calculations by Witthoeft and Badnell. However, there are important differences for some transitions with the previous calculations. The corrections to the previous results are mainly due to more extensive expansions for the Fe VII target states.

  17. Chang'e-3 Extreme Ultraviolet Camera Observations of the Dynamics of the Earth's Plasmasphere

    NASA Astrophysics Data System (ADS)

    Fok, M. C. H.; Zhang, X.; He, F.; Chen, B.; Wang, H. N.; Shen, C.; Ping, J.; Nakano, S.

    2015-12-01

    The Moon-based Extreme Ultraviolet Camera (EUVC) aboard China's Chang'e-3 (CE-3) lunar lander has successfully imaged the global plasmasphere on the Moon for the first time through detecting the resonantly scattered sunlight by plasmaspheric He+ at 30.4 nm with a spatial resolution of 0.1 RE and a time resolution of 10 min. The characteristics and the analyzing methods of the EUVC images are introduced in detail in this report. The plasmapause locations on the magnetic equator are reconstructed with the Minimum L Algorithm and are quantitatively compared with those extracted from in-situ observations by DMSP, THEMIS, and RBSP satellites. Then the plasmapause evolutions during substorms on February 21 2014 and April 21 2014 are investigated. It is found that the evolutions of plasmapause correlate well in both universal time and magnetic local time with the equatorial boundaries of auroral oval during substorms. During these two cases, the solar-wind-driven convection and the geomagnetic activity are relatively weak and steady, and the plasmapause motions can reliably be attributed to the substorms. It is proposed that correlations between the auroral signatures and the plasmapause motions may be due to the generation and Earthward-propagation of dipolarization front and resultant pitch angle scattering. In future work, we will search more in-situ and remote sensing data in both the plasmasphere and the magnetotail regions to investigate the correlations between the plasmaspheric erosions, the dipolarization fronts, and the energetic ions injections.

  18. Study of Solar Energetic Particle Associations with Coronal Extreme-ultraviolet Waves

    NASA Astrophysics Data System (ADS)

    Park, Jinhye; Innes, D. E.; Bucik, R.; Moon, Y.-J.; Kahler, S. W.

    2015-07-01

    We study the relationship between large gradual solar energetic particle (SEP) events and associated extreme-ultraviolet (EUV) wave properties in 16 events that occurred between 2010 August and 2013 May and were observed by SDO, the Solar and Heliospheric Observatory (SOHO), and/or STEREO. We determine onset times, peak times, and peak fluxes of the SEP events in the SOHO/ERNE and STEREO/LET proton channels (6-10 MeV). The EUV wave arrival times and their speeds from the source sites to the spacecraft footpoints in the photosphere, which are magnetically connected to the spacecraft by Parker spiral and potential fields, are determined by spacetime plots from the full-Sun heliographic images created by combining STEREO-A and STEREO-B 195 Å and SDO 193 Å images. The SEP peak fluxes increase with the EUV wave speeds, and the SEP spectral indices become harder with the speeds. This shows that higher energetic particle fluxes are associated with faster EUV waves, which are considered as the lateral expansions of coronal-mass-ejection-driven shocks in the low corona.

  19. Comparative study of line roughness metrics of chemically amplified and inorganic resists for extreme ultraviolet

    NASA Astrophysics Data System (ADS)

    Fallica, Roberto; Buitrago, Elizabeth; Ekinci, Yasin

    2016-07-01

    We present a comprehensive comparative study of the roughness metrics of different resists. Dense line/space of polymethyl methacrylate, hydrogen silsesquioxane, a metal oxide-based resist, and different chemically amplified resists (CARs) have been patterned by extreme ultraviolet interference lithography. All three line width roughness (LWR) metrics: the root-mean-square (r.m.s.) roughness value σLWR, the correlation length ξ, and the roughness exponent α, were extracted by metrological analysis of top-down SEM images. We found that all metrics are required to fully describe the overall roughness of each resist. Our measurements indicate that in fact, a few of the state-of-the-art resists tested here can meet the International Technology Roadmap for Semiconductors requirements for σLWR. The correlation length ξ was also found to be considerably higher in polymer-based materials in comparison to nonpolymers. Finally, the roughness exponent α, interpreted using the concept of fractal geometry, was found to be mainly affected by acid diffusion in CARs, where it produces line edges with a higher complexity than in non-CAR resists. These results indicate that the different resists platforms show very different LWR metrics and roughness is not manifested only in the σLWR but in all parameters. Therefore, all roughness metrics should be taken into account when comparing the performance among different resists since they ultimately have a substantial impact on device performance.

  20. DIET Processes on Ruthenium Surfaces Related to Extreme Ultraviolet Lithography (EUVL)

    SciTech Connect

    Yakshinskiy, B.; Wasielewski, R; Loginova, E; Hedhili, M; Madey, T

    2008-01-01

    The aim of this work is to provide insights into desorption induced by electronic transitions (DIET) processes that affect the reflectivity of ruthenium-capped Mo/Si multilayer mirrors working under EUVL (extreme ultraviolet lithography) operating conditions (high vacuum, and 13.5 nm (92 eV) photons). Critical issues are associated with possible oxidation of the 2 nm thick Ru capping layer due to the inevitable background pressure of H{sub 2}O, and carbon build up due to background hydrocarbons. In the present work, we discuss aspects of the radiation-induced surface chemistry of Ru irradiated by 100 eV electrons and 92 eV photons. The cross section for electron-stimulated desorption of oxygen from O-covered Ru is 6 x 10{sup -19} cm{sup 2}. Carbon accumulation several nm thick occurs on the Ru surface during electron irradiation in methyl methacrylate (MMA) vapor, a model background impurity hydrocarbon. Radiation damage by low-energy secondary electrons is believed to dominate over direct photoexcitation of adsorbates under EUVL conditions. The secondary electron yield from Ru varies strongly with photon energy, and is 0.02 electrons/photon at 92 eV.

  1. Considerations for a free-electron laser-based extreme-ultraviolet lithography program

    NASA Astrophysics Data System (ADS)

    Hosler, Erik R.; Wood, Obert R.; Barletta, William A.; Mangat, Pawitter J. S.; Preil, Moshe E.

    2015-03-01

    Recent years have seen great strides in the development of extreme ultraviolet (EUV) laser-produced plasma sources. Field deployed EUV exposure tools are now capable of facilitating advanced technology node development. Nevertheless, as the required manufacturing exposure dose scales, EUV sources must follow suit and provide 500- 1000 W to maintain production throughputs. A free-electron laser (FEL) offers a cost effective, single-source alternative for powering an entire EUV lithography program. FEL integration into semiconductor fab architecture will require both unique facility considerations as well as a paradigm shift in lithography operations. Critical accelerator configurations relating to energy recovery, multi-turn acceleration, and operational mode are discussed from engineering/scientific, cost-minimization, and safety perspectives. Furthermore, the individual components of a FEL (electron injector, RF systems, undulator, etc.) are examined with respect to both design and cost, considering existing technology as well as prospective innovations. Finally, FEL development and deployment roadmaps are presented, focusing on manufacturer deployment for the 5 nm or 3 nm technology nodes.[1-3

  2. Diagnosis of energy transport in iron buried layer targets using an extreme ultraviolet laser

    SciTech Connect

    Shahzad, M.; Culfa, O.; Rossall, A. K.; Tallents, G. J.; Wilson, L. A.; Guilbaud, O.; Kazamias, S.; Delmas, O.; Demailly, J.; Maitrallain, A.; Pittman, M.; Baynard, E.; Farjardo, M.

    2015-02-15

    We demonstrate the use of extreme ultra-violet (EUV) laboratory lasers in probing energy transport in laser irradiated solid targets. EUV transmission through targets containing a thin layer of iron (50 nm) encased in plastic (CH) after irradiation by a short pulse (35 fs) laser focussed to irradiances 3 × 10{sup 16} Wcm{sup −2} is measured. Heating of the iron layer gives rise to a rapid decrease in EUV opacity and an increase in the transmission of the 13.9 nm laser radiation as the iron ionizes to Fe{sup 5+} and above where the ion ionisation energy is greater than the EUV probe photon energy (89 eV). A one dimensional hydrodynamic fluid code HYADES has been used to simulate the temporal variation in EUV transmission (wavelength 13.9 nm) using IMP opacity values for the iron layer and the simulated transmissions are compared to measured transmission values. When a deliberate pre-pulse is used to preform an expanding plastic plasma, it is found that radiation is important in the heating of the iron layer while for pre-pulse free irradiation, radiation transport is not significant.

  3. Extreme-ultraviolet polarimeter utilizing laser-generated high-order harmonics.

    PubMed

    Brimhall, Nicole; Turner, Matthew; Herrick, Nicholas; Allred, David D; Turley, R Steven; Ware, Michael; Peatross, Justin

    2008-10-01

    We describe an extreme-ultraviolet (EUV) polarimeter that employs laser-generated high-order harmonics as the light source. The polarimeter is designed to characterize materials and thin films for use with EUV light. Laser high harmonics are highly directional with easily rotatable linear polarization, not typically available with other EUV sources. The harmonics have good wavelength coverage, potentially spanning the entire EUV from a few to a hundred nanometers. Our instrument is configured to measure reflectances from 14 to 30 nm and has approximately 180 spectral resolution (lambda/Delta lambda). The reflection from a sample surface can be measured over a continuous range of incident angles (5 degrees-75 degrees). A secondary 14 cm gas cell attenuates the harmonics in a controlled way to keep signals within the linear dynamic range of the detector, comprised of a microchannel plate coupled to a phosphorous screen and charge coupled device camera. The harmonics are produced using approximately 10 mJ, approximately 35 fs, and approximately 800 nm laser pulses with a repetition rate of 10 Hz. Per-shot energy monitoring of the laser discriminates against fluctuations. The polarimeter reflectance data agree well with data obtained at the Advanced Light Source Synchrotron (Beamline 6.3.2).

  4. Infrared-laser-assisted photoionization of helium by coherent extreme ultraviolet light

    SciTech Connect

    Tong Xiaomin; Toshima, Nobuyuki

    2010-04-15

    We investigate the infrared (IR)-laser-assisted photoionization of He by a coherent extreme ultraviolet (euv) light solving the time-dependent Schroedinger equation. A combined field of the 13th and 15th harmonics created from the same IR laser source is used to ionize He atoms coherently. We show that the ionization probabilities oscillate as a function of the time delay between the IR and the euv pulses. On the other hand, the oscillation amplitude increases as the IR intensity increases, reaches a maximum when the IR intensity is around 6x10{sup 12} W/cm{sup 2}, and then decreases as the IR intensity increases further. Decomposing the ionization probabilities by the 13th and 15th harmonics, we illustrate that the oscillation amplitude is small for a lower IR laser intensity due to the fact that the transition strength by the 13th harmonic is much smaller than the one by the 15th harmonic. When the IR intensity increases further above 6x10{sup 12} W/cm{sup 2}, the transition strength by the 13th harmonic becomes larger than the one by the 15th harmonic and the oscillation amplitude is reduced again. By tuning the relative field strengths of the 13th and 15th harmonics or the IR intensity, we can control the oscillation amplitude.

  5. Real-time and sub-wavelength ultrafast coherent diffraction imaging in the extreme ultraviolet.

    PubMed

    Zürch, M; Rothhardt, J; Hädrich, S; Demmler, S; Krebs, M; Limpert, J; Tünnermann, A; Guggenmos, A; Kleineberg, U; Spielmann, C

    2014-12-08

    Coherent Diffraction Imaging is a technique to study matter with nanometer-scale spatial resolution based on coherent illumination of the sample with hard X-ray, soft X-ray or extreme ultraviolet light delivered from synchrotrons or more recently X-ray Free-Electron Lasers. This robust technique simultaneously allows quantitative amplitude and phase contrast imaging. Laser-driven high harmonic generation XUV-sources allow table-top realizations. However, the low conversion efficiency of lab-based sources imposes either a large scale laser system or long exposure times, preventing many applications. Here we present a lensless imaging experiment combining a high numerical aperture (NA = 0.8) setup with a high average power fibre laser driven high harmonic source. The high flux and narrow-band harmonic line at 33.2 nm enables either sub-wavelength spatial resolution close to the Abbe limit (Δr = 0.8λ) for long exposure time, or sub-70 nm imaging in less than one second. The unprecedented high spatial resolution, compactness of the setup together with the real-time capability paves the way for a plethora of applications in fundamental and life sciences.

  6. Wafer and reticle positioning system for the Extreme Ultraviolet Lithography Engineering Test Stand

    SciTech Connect

    WRONOSKY,JOHN B.; SMITH,TONY G.; CRAIG,MARCUS J.; STURGIS,BEVERLY R.; DARNOLD,JOEL R.; WERLING,DAVID K.; KINCY,MARK A.; TICHENOR,DANIEL A.; WILLIAMS,MARK E.; BISCHOFF,PAUL

    2000-01-27

    This paper is an overview of the wafer and reticle positioning system of the Extreme Ultraviolet Lithography (EUVL) Engineering Test Stand (ETS). EUVL represents one of the most promising technologies for supporting the integrated circuit (IC) industry's lithography needs for critical features below 100nm. EUVL research and development includes development of capabilities for demonstrating key EUV technologies. The ETS is under development at the EUV Virtual National Laboratory, to demonstrate EUV full-field imaging and provide data that supports production-tool development. The stages and their associated metrology operated in a vacuum environment and must meet stringent outgassing specifications. A tight tolerance is placed on the stage tracking performance to minimize image distortion and provide high position repeatability. The wafer must track the reticle with less than {+-}3nm of position error and jitter must not exceed 10nm rms. To meet these performance requirements, magnetically levitated positioning stages utilizing a system of sophisticated control electronics will be used. System modeling and experimentation have contributed to the development of the positioning system and results indicate that desired ETS performance is achievable.

  7. Mode Conversion of a Solar Extreme-ultraviolet Wave over a Coronal Cavity

    NASA Astrophysics Data System (ADS)

    Zong, Weiguo; Dai, Yu

    2017-01-01

    We report on observations of an extreme-ultraviolet (EUV) wave event in the Sun on 2011 January 13 by Solar Terrestrial Relations Observatory and Solar Dynamics Observatory in quadrature. Both the trailing edge and the leading edge of the EUV wave front in the north direction are reliably traced, revealing generally compatible propagation velocities in both perspectives and a velocity ratio of about 1/3. When the wave front encounters a coronal cavity near the northern polar coronal hole, the trailing edge of the front stops while its leading edge just shows a small gap and extends over the cavity, meanwhile getting significantly decelerated but intensified. We propose that the trailing edge and the leading edge of the northward propagating wave front correspond to a non-wave coronal mass ejection component and a fast-mode magnetohydrodynamic wave component, respectively. The interaction of the fast-mode wave and the coronal cavity may involve a mode conversion process, through which part of the fast-mode wave is converted to a slow-mode wave that is trapped along the magnetic field lines. This scenario can reasonably account for the unusual behavior of the wave front over the coronal cavity.

  8. At-wavelength characterization of the extreme ultraviolet Engineering Test Stand Set-2 optic

    SciTech Connect

    Naulleau, Patrick; Goldberg, Kenneth A.; Anderson, Erik H.; Batson, Phillip; Denham, Paul E.; Jackson, Keith H.; Gullikson, Eric M.; Rekawa, Senajith; Bokor, Jeffrey

    2001-06-10

    At-wavelength interferometric characterization of a new 4x-reduction lithographic-quality extreme ultraviolet (EUV) optical system is described. This state-of-the-art projection optic was fabricated for installation in the EUV lithography Engineering Test Stand (ETS) and is referred to as the ETS Set-2 optic. EUV characterization of the Set-2 optic is performed using the EUV phase-shifting point diffraction interferometer (PS/PDI) installed on an undulator beamline at Lawrence Berkeley National Laboratory's Advanced Light Source. This is the same interferometer previously used for the at-wavelength characterization and alignment of the ETS Set-1 optic. In addition to the PS/PDI-based full-field wavefront characterization, we also present wavefront measurements performed with lateral shearing interferometry, the chromatic dependence of the wavefront error, and the system-level pupil-dependent spectral-bandpass characteristics of the optic; the latter two properties are only measurable using at-wavelength interferometry.

  9. Deprotection blue in extreme ultraviolet photoresists: influence of base loading and post-exposure bake temperture

    SciTech Connect

    Anderson, Christopher N.; Naulleau, Patrick P.

    2008-06-02

    The deprotection blur of Rohm and Haas XP 5435, XP 5271, and XP5496 extreme ultraviolet photoresists has been determined as their base weight percent is varied. They have also determined the deprotection blur of TOK EUVR P1123 photoresist as the post-exposure bake temperature is varied from 80 C to 120 C. In Rohm and Haas XP 5435 and XP5271 resists 7x and 3x (respective) increases in base weight percent reduce the size of successfully patterned 1:1 line-space features by 16 nm and 8 nm with corresponding reductions in deprotection blur of 7 nm and 4 nm. In XP 5496 a 7x increase in base weight percent reduces the size of successfully patterned 1:1 line-space features from 48 nm to 38 nm without changing deprotection blur. In TOK EUVR P1123 resist, a reduction in post-exposure bake temperature from 100 C to 80 C reduces deprotection blur from 21 nm to 10 nm and reduces patterned LER from 4.8 nm to 4.1 nm.

  10. Simulation of particle velocity in a laser-produced tin plasma extreme ultraviolet source

    NASA Astrophysics Data System (ADS)

    Masnavi, Majid; Nakajima, Mitsuo; Horioka, Kazuhiko; Araghy, Homaira Parchamy; Endo, Akira

    2011-06-01

    In connection with fast heating in a laser produced plasma (LPP) extreme ultraviolet (EUV) source, the superheating behavior of bulk tin (Sn) at high heating rates is investigated. A constant temperature and pressure molecular dynamics simulation using modified Lennard-Jones and Coulomb potentials suitable for studying the liquid structure of Sn is employed in order to derive the caloric curves of the solid and liquid phases. The results have shown transient effects on the phase transitions. Superheating is observed during the melting and vaporizing processes. The velocity distribution of Sn particles against typical laser fluence in a LPP EUV light source has been numerically investigated using a simplified method including a one-dimensional, two-temperature, molecular dynamics, and steady-state ionization model. In the framework of our model, it was found that ejected Sn particles have a maximum velocity on the order of 10 to 40 km/s in plasma created using a nanosecond pre-pulse neodymium-doped yttrium aluminum garnet (Nd:YAG, 1.06 μm) laser in EUV lithography experiments.

  11. Viability of pattern shift for defect-free extreme ultraviolet lithography photomasks

    NASA Astrophysics Data System (ADS)

    Qi, Zhengqing John; Rankin, Jed; Narita, Eisuke; Kagawa, Masayuki

    2016-04-01

    Several challenges hinder extreme ultraviolet lithography (EUVL) photomask fabrication and its readiness for high-volume manufacturing (HVM). The lack in availability of pristine defect-free blanks as well as the absence of a robust mask repair technique mandates defect mitigation through pattern shift for the production of defect-free photomasks. By using known defect locations on a blank, the mask design can be intentionally shifted to avoid patterning directly over a defect. The work presented here provides a comprehensive look at pattern shift implementation to intersect EUV HVM for the 7-nm technology node (N7). An empirical error budget to compensate for various measurement errors, based on the latest HVM inspection and write tool capabilities, is first established and then verified postpatterning. The validated error budget is applied to 20 representative EUV blanks and pattern shift is performed using fully functional N7 chip designs that were recently used to fabricate working silicon-germanium devices. Probability of defect-free masks are explored for various N7 photomask levels, including metal, contact, and gate cut layers. From these results, an assessment is made on the current viability of defect-free EUV masks and what is required to construct a complete defect-free EUV mask set.

  12. Resist Materials for Extreme Ultraviolet Lithography: Toward Low-Cost Single-Digit-Nanometer Patterning.

    PubMed

    Ashby, Paul D; Olynick, Deirdre L; Ogletree, D Frank; Naulleau, Patrick P

    2015-10-14

    Extreme ultraviolet lithography (EUVL) is the leading technology for enabling miniaturization of computational components over the next decade. Next-generation resists will need to meet demanding performance criteria of 10 nm critical dimension, 1.2 nm line-edge roughness, and 20 mJ cm(-2) exposure dose. Here, the current state of the development of EUV resist materials is reviewed. First, pattern formation in resist materials is described and the Hansen solubility sphere (HSS) is used as a framework for understanding the pattern-development process. Then, recent progress in EUVL resist chemistry and characterization is discussed. Incremental advances are obtained by transferring chemically amplified resist materials developed for 193 nm lithography to EUV wavelengths. Significant advances will result from synthesizing high-absorbance resist materials using heavier atoms. In the framework of the HSS model, these materials have significant room for improvement and thus offer great promise as high-performance EUV resists for patterning of sub-10 nm features.

  13. A Molecular- and Nano-Electronics Test (MONET) platform fabricated using extreme ultraviolet lithography.

    SciTech Connect

    Dentinger, Paul M.; Cardinale, Gregory F.; Hunter, Luke L.; Talin, Albert Alec

    2003-12-01

    We describe the fabrication and characterization of an electrode array test structure, designed for electrical probing of molecules and nanocrystals. We use Extreme Ultraviolet Lithography (EUVL) to define the electrical test platform features. As fabricated, the platform includes nominal electrode gaps of 0 nm, 40 nm, 60 nm, and 80 nm. Additional variation in electrode gap is achieved by controlling the exposure conditions, such as dose and focus. To enable EUVL based nanofabrication, we develop a novel bi-level photoresist process. The bi-level photoresist consists of a combination of a commercially available polydimethylglutarimide (PMGI) bottom layer and an experimental EUVL photoresist top (imaging) layer. We measure the sensitivity of PMGI to EUV exposure dose as a function of photoresist pre-bake temperature, and using this data, optimize a metal lift-off process. Reliable fabrication of 700 Angstrom thick Au structures with sub-1000 Angstrom critical dimensions is achieved, even without the use of a Au adhesion layer, such as Ti. Several test platforms are used to characterize electrical properties of organic molecules deposited as self assembled monolayers.

  14. Thermalization of electrons in decaying extreme ultraviolet photons induced low pressure argon plasma

    NASA Astrophysics Data System (ADS)

    Beckers, J.; van der Horst, R. M.; Osorio, E. A.; Kroesen, G. M. W.; Banine, V. Y.

    2016-06-01

    We monitored—in the pressure range: 0.5-15 Pa—the electron temperature in decaying plasmas induced in argon gas by pulsed irradiation with extreme ultraviolet (EUV) photons with wavelengths closely around 13.5 nm. For this purpose, temporal measurements of the space-averaged and electric field weighted electron density after pulsed EUV irradiation are combined with an ambipolar diffusion model of the plasma. Results demonstrate that electrons are thermalized to room temperature before the plasma has fully expanded to the chamber walls for pressures of 3 Pa and higher. At pressures below 3 Pa, the electron temperature was found to be up to 0.1 eV above room temperature which is explained by the fact that plasma expansion is too quick for the electrons to fully thermalize. The comparison between plasma expansion duration towards a surface, plasma decay at a surface and time needed for thermalization and cooling of electrons is essential for designers of EUV lithography tools and EUV sources since the temperature of electrons dictates many fundamental physical processes.

  15. TEMPERATURE AND EXTREME-ULTRAVIOLET INTENSITY IN A CORONAL PROMINENCE CAVITY AND STREAMER

    SciTech Connect

    Kucera, T. A.; Tripathi, D.

    2012-09-20

    We analyze the temperature and EUV line emission of a coronal cavity and surrounding streamer in terms of a morphological forward model. We use a series of iron line ratios observed with the Hinode Extreme-ultraviolet Imaging Spectrograph (EIS) on 2007 August 9 to constrain temperature as a function of altitude in a morphological forward model of the streamer and cavity. We also compare model predictions to the EIS EUV line intensities and polarized brightness (pB) data from the Mauna Loa Solar Observatory (MLSO) Mark 4 K-coronameter. This work builds on earlier analysis using the same model to determine geometry of and density in the same cavity and streamer. The fit to the data with altitude-dependent temperature profiles indicates that both the streamer and cavity have temperatures in the range 1.4-1.7 MK. However, the cavity exhibits substantial substructure such that the altitude-dependent temperature profile is not sufficient to completely model conditions in the cavity. Coronal prominence cavities are structured by magnetism so clues to this structure are to be found in their plasma properties. These temperature substructures are likely related to structures in the cavity magnetic field. Furthermore, we find that the model overestimates the EUV line intensities by a factor of 4-10, without overestimating pB. We discuss this difference in terms of filling factors and uncertainties in density diagnostics and elemental abundances.

  16. Scanning coherent diffractive imaging methods for actinic extreme ultraviolet mask metrology

    NASA Astrophysics Data System (ADS)

    Helfenstein, Patrick; Mohacsi, Istvan; Rajeev, Rajendran; Ekinci, Yasin

    2016-07-01

    For the successful implementation of extreme ultraviolet (EUV) lithography in the upcoming technology nodes, a major challenge to overcome is the stable and reliable detection and characterization of mask defects. We have recently presented a reflective mode EUV mask scanning lensless imaging tool (RESCAN) which was installed at the XIL-II beamline of the swiss light source and showed reconstructed aerial images of test patterns on EUV masks. RESCAN uses scanning coherent diffractive imaging (SCDI) methods to obtain actinic aerial images of EUV photomasks and was designed for 80 nm onmask resolution. Our SCDI algorithm reconstructs the measured sample by iteratively solving the phase problem using overdetermined diffraction data gathered by scanning across the specimen with a finite illumination. It provides the phase and amplitude aerial images of EUV photomasks with high resolution without the need to use high numerical aperture (NA) lenses. Contrary to scanning microscopy and full-field microscopy, where the resolution is limited by the spot size or NA of the lens, the achievable resolution with our method depends on the detector noise and NA of the detector. To increase the resolution of our tool, we upgraded RESCAN with a detector and algorithms. Here, we present the results obtained with the tool that is capable of up to 40-nm onmask resolution. We believe that the realization of our prototype marks a significant step toward overcoming the limitations imposed by methods relying on imaging optics and shows a viable solution for actinic mask metrology.

  17. Multilayer coated optics for an alpha-class extreme ultraviolet lithography system

    SciTech Connect

    Folta, J A; Grabner, R F; Hudyma, R M; Montcalm, C; Schmidt, M A; Spiller, E; Walton, C C; Wedowski, M

    1999-08-25

    We present the results of coating the first set of optical elements for an alpha-class extreme-ultraviolet (EUV) lithography system, the Engineering Test Stand (ETS). The optics were coated with Mo/Si multilayer mirrors using an upgraded DC-magnetron sputtering system. Characterization of the near-normal incidence EUV reflectance was performed using synchrotron radiation from the Advanced Light Source at the Lawrence Berkeley National Laboratory. Stringent requirements were met for these multilayer coatings in terms of reflectance, wavelength matching among the different optics, and thickness control across the diameter of each individual optic. Reflectances above 65% were achieved at 13.35 nm at near-normal angles of incidence. The run-to-run reproducibility of the reflectance peak wavelength was maintained to within 0.4%, providing the required wavelength matching among the seven multilayer-coated optics. The thickness uniformity (or gradient) was controlled to within {+-}0.25% peak-to-valley (P-V) for the condenser optics and {+-}0.1% P-V for the four projection optics, exceeding the prescribed specification for the optics of the ETS.

  18. Extreme Ultraviolet Fractional Orbital Angular Momentum Beams from High Harmonic Generation

    PubMed Central

    Turpin, Alex; Rego, Laura; Picón, Antonio; San Román, Julio; Hernández-García, Carlos

    2017-01-01

    We investigate theoretically the generation of extreme-ultraviolet (EUV) beams carrying fractional orbital angular momentum. To this end, we drive high-order harmonic generation with infrared conical refraction (CR) beams. We show that the high-order harmonic beams emitted in the EUV/soft x-ray regime preserve the characteristic signatures of the driving beam, namely ringlike transverse intensity profile and CR-like polarization distribution. As a result, through orbital and spin angular momentum conservation, harmonic beams are emitted with fractional orbital angular momentum, and they can be synthesized into structured attosecond helical beams –or “structured attosecond light springs”– with rotating linear polarization along the azimuth. Our proposal overcomes the state of the art limitations for the generation of light beams far from the visible domain carrying non-integer orbital angular momentum and could be applied in fields such as diffraction imaging, EUV lithography, particle trapping, and super-resolution imaging. PMID:28281655

  19. Electron Impact Excitation Collision Strengths for Extreme Ultraviolet Lines of Fe VII

    NASA Astrophysics Data System (ADS)

    Tayal, S. S.; Zatsarinny, O.

    2014-06-01

    Extensive calculations have been performed for electron impact excitation collision strengths and oscillator strengths for the Fe VII extreme ultraviolet lines of astrophysical importance. The collision strengths for fine-structure transitions are calculated in the B-spline Breit-Pauli R-matrix approach. The target wavefunctions have been calculated in the multiconfiguration Hartree-Fock method with term-dependent non-orthogonal orbitals. The close-coupling expansion includes 189 fine-structure levels of Fe VII belonging to terms of the ground 3p 63d 2 and excited 3p 53d 3, 3p 63d4l, 3p 63d5s, and 3p 63d5p configurations. The effective collision strengths are determined from the electron excitation collision strengths by integration over a Maxwellian distribution of electron velocities. The effective collision strengths are provided for 17766 fine-structure transitions at electron temperatures from 104 to 107 K. Our results normally agree with the previous R-matrix frame-transformation calculations by Witthoeft & Badnell. However, there are important differences for some transitions with the previous calculations. The corrections to the previous results are mainly due to more extensive expansions for the Fe VII target states.

  20. Experimental study of a shearing interferometer concept for at-wavelength characterization of extreme-ultraviolet optics.

    PubMed

    Hegeman, P; Christmann, X; Visser, M; Braat, J

    2001-09-01

    We describe the experimental evaluation of a shearing interferometer concept for at-wavelength testing of extreme-ultraviolet optics. The concept is based on the Ronchi test, which has been modified by a new design for entrance and exit gratings to suppress disturbing higher-order interference patterns. The interferometer concept has been tested on an experimental setup, of which all relevant parameters have been scaled from extreme-ultraviolet to visible-light wavelengths. A Twyman-Green interferometer has been integrated into the setup for comparison with the improved Ronchi test. A systematic difference of 7-12 mlambda rms has been found between wave fronts measured with the improved Ronchi test and with the Twyman-Green interferometer. Possible error sources have been analyzed. The accuracy of the interferometer is estimated to be 10 mlambda rms.

  1. Systematic investigation of self-absorption and conversion efficiency of 6.7 nm extreme ultraviolet sources

    SciTech Connect

    Otsuka, Takamitsu; Higashiguchi, Takeshi; Yugami, Noboru; Yatagai, Toyohiko; Kilbane, Deirdre; Dunne, Padraig; O'Sullivan, Gerry; Jiang, Weihua; Endo, Akira

    2010-12-06

    We have investigated the dependence of the spectral behavior and conversion efficiencies of rare-earth plasma extreme ultraviolet sources with peak emission at 6.7 nm on laser wavelength and the initial target density. The maximum conversion efficiency was 1.3% at a laser intensity of 1.6x10{sup 12} W/cm{sup 2} at an operating wavelength of 1064 nm, when self-absorption was reduced by use of a low initial density target. Moreover, the lower-density results in a narrower spectrum and therefore improved spectral purity. It is shown to be important to use a low initial density target and/or to produce low electron density plasmas for efficient extreme ultraviolet sources when using high-Z targets.

  2. Reflectance enhancement in the extreme ultraviolet and soft x rays by means of multilayers with more than two materials.

    PubMed

    Larruquert, Juan I

    2002-02-01

    Sub-quarterwave multilayer coatings with more than two different materials are shown to provide a reflectance enhancement compared with the standard two-material multilayer coatings when reflectance is limited by material absorption. A remarkable reflectance enhancement is obtained when the materials in the multilayer are moderately absorbing. A simple rule based on the material optical constants is provided to select the most suitable materials for the multilayer and to arrange the materials in the correct sequence in order to obtain the highest possible reflectance. It is shown that sub-quarterwave multilayers generalize the concept of multilayers, of which the standard two-material multilayers are a particular case. Various examples illustrate the benefit of sub-quarter-wave multilayer coatings for highest reflectance in the extreme ultraviolet. Applications for sub-quarterwave multilayer coatings are envisaged for astronomy in the extreme ultraviolet (EUV) and soft x rays and also for future EUY lithography.

  3. Feasibility of using Extreme Ultraviolet Explorer (EUVE) reaction wheels to satisfy Space Infrared Telescope Facility (SIRTF) maneuver requirements

    NASA Technical Reports Server (NTRS)

    Lightsey, W. D.

    1990-01-01

    A digital computer simulation is used to determine if the extreme ultraviolet explorer (EUVE) reaction wheels can provide sufficient torque and momentum storage capability to meet the space infrared telescope facility (SIRTF) maneuver requirements. A brief description of the pointing control system (PCS) and the sensor and actuator dynamic models used in the simulation is presented. A model to represent a disturbance such as fluid sloshing is developed. Results developed with the simulation, and a discussion of these results are presented.

  4. Earth-orbiting extreme ultraviolet spectroscopic mission: SPRINT-A/EXCEED

    NASA Astrophysics Data System (ADS)

    Yoshikawa, I.; Tsuchiya, F.; Yamazaki, A.; Yoshioka, K.; Uemizu, K.; Murakami, G.; Kimura, T.; Kagitani, M.; Terada, N.; Kasaba, Y.; Sakanoi, T.; Ishii, H.; Uji, K.

    2012-09-01

    The EXCEED (Extreme Ultraviolet Spectroscope for Exospheric Dynamics) mission is an Earth-orbiting extreme ultraviolet (EUV) spectroscopic mission and the first in the SPRINT series being developed by ISAS/JAXA. It will be launched in the summer of 2013. EUV spectroscopy is suitable for observing tenuous gases and plasmas around planets in the solar system (e.g., Mercury, Venus, Mars, Jupiter, and Saturn). Advantage of remote sensing observation is to take a direct picture of the plasma dynamics and distinguish between spatial and temporal variability explicitly. One of the primary observation targets is an inner magnetosphere of Jupiter, whose plasma dynamics is dominated by planetary rotation. Previous observations have shown a few percents of the hot electron population in the inner magnetosphere whose temperature is 100 times higher than the background thermal electrons. Though the hot electrons have a significant impact on the energy balance in the inner magnetosphere, their generation process has not yet been elucidated. In the EUV range, a number of emission lines originate from plasmas distributed in Jupiter's inner magnetosphere. The EXCEED spectrograph is designed to have a wavelength range of 55-145 nm with minimum spectral resolution of 0.4 nm, enabling the electron temperature and ion composition in the inner magnetosphere to be determined. Another primary objective is to investigate an unresolved problem concerning the escape of the atmosphere to space. Although there have been some in-situ observations by orbiters, our knowledge is still limited. The EXCEED mission plans to make imaging observations of plasmas around Venus and Mars to determine the amounts of escaping atmosphere. The instrument's field of view (FOV) is so wide that we can get an image from the interaction region between the solar wind and planetary plasmas down to the tail region at one time. This will provide us with information about outward-flowing plasmas, e.g., their composition

  5. Structure and extreme ultraviolet performance of Si/C multilayers deposited under different working pressures.

    PubMed

    Yi, Qiang; Huang, Qiushi; Wang, Xiangmei; Yang, Yang; Yang, Xiaowei; Zhang, Zhong; Wang, Zhanshan; Xu, Rongkun; Peng, Taiping; Zhou, Hongjun; Huo, Tonglin

    2017-02-01

    Narrow bandwidth Si/C multilayer mirrors are fabricated and characterized for the Z-pinch plasma diagnostic at a wavelength of 16.5 nm. To reduce the large stress of the multilayer and maintain a practical reflectivity, different working pressures, from 0.13 Pa to 0.52 Pa, are optimized during the deposition. The grazing incidence x-ray reflectometry (GIXR) measurement and the fitting results indicate that an interlayer was formed at the interfaces, while both the interlayer thickness and interface widths increase with larger working pressure. The surface roughness of the multilayers also increases from 0.13 nm at 0.13 Pa to 0.29 nm at 0.52 Pa, as revealed by the atomic force microscope (AFM) measurements. The multilayer stress decreases from -682 MPa to -384  MPa as the working pressure increases from 0.13 Pa to 0.52 Pa, respectively. The experimental extreme ultraviolet (EUV) reflectivity of the samples with 20 bilayers gradually decreased from 26.3% to 18.9% with increased working pressure. The bandwidth of the reflection peak remains similar for the different samples with a full width half-maximum (FWHM) value of around 0.87 nm. A maximum EUV reflectivity of 33.2% and a bandwidth of 0.64 nm were achieved by the sample with 50 bilayers fabricated under a working pressure of 0.13 Pa.

  6. ACTIVE REGION MOSS: DOPPLER SHIFTS FROM HINODE/EXTREME-ULTRAVIOLET IMAGING SPECTROMETER OBSERVATIONS

    SciTech Connect

    Tripathi, Durgesh; Mason, Helen E.; Klimchuk, James A.

    2012-07-01

    Studying the Doppler shifts and the temperature dependence of Doppler shifts in moss regions can help us understand the heating processes in the core of the active regions. In this paper, we have used an active region observation recorded by the Extreme-ultraviolet Imaging Spectrometer (EIS) on board Hinode on 2007 December 12 to measure the Doppler shifts in the moss regions. We have distinguished the moss regions from the rest of the active region by defining a low-density cutoff as derived by Tripathi et al. in 2010. We have carried out a very careful analysis of the EIS wavelength calibration based on the method described by Young et al. in 2012. For spectral lines having maximum sensitivity between log T = 5.85 and log T = 6.25 K, we find that the velocity distribution peaks at around 0 km s{sup -1} with an estimated error of 4-5 km s{sup -1}. The width of the distribution decreases with temperature. The mean of the distribution shows a blueshift which increases with increasing temperature and the distribution also shows asymmetries toward blueshift. Comparing these results with observables predicted from different coronal heating models, we find that these results are consistent with both steady and impulsive heating scenarios. However, the fact that there are a significant number of pixels showing velocity amplitudes that exceed the uncertainty of 5 km s{sup -1} is suggestive of impulsive heating. Clearly, further observational constraints are needed to distinguish between these two heating scenarios.

  7. THE FIRST STRAY LIGHT CORRECTED EXTREME-ULTRAVIOLET IMAGES OF SOLAR CORONAL HOLES

    SciTech Connect

    Shearer, Paul; Gilbert, Anna C.; Frazin, Richard A.; Hero III, Alfred O. E-mail: annacg@umich.edu E-mail: hero@umich.edu

    2012-04-10

    Coronal holes are the source regions of the fast solar wind, which fills most of the solar system volume near the cycle minimum. Removing stray light from extreme-ultraviolet (EUV) images of the Sun's corona is of high astrophysical importance, as it is required to make meaningful determinations of temperatures and densities of coronal holes. EUV images tend to be dominated by the component of the stray light due to the long-range scatter caused by the microroughness of telescope mirror surfaces, and this component has proven very difficult to measure in pre-flight characterization. In-flight characterization heretofore has proven elusive due to the fact that the detected image is simultaneously nonlinear in two unknown functions: the stray light pattern and the true image that would be seen by an ideal telescope. Using a constrained blind deconvolution technique that takes advantage of known zeros in the true image provided by a fortuitous lunar transit, we have removed the stray light from solar images seen by the EUVI instrument on STEREO-B in all four filter bands (171, 195, 284, and 304 A). Uncertainty measures of the stray light corrected images, which include the systematic error due to misestimation of the scatter, are provided. It is shown that in EUVI, stray light contributes up to 70% of the emission in coronal holes seen on the solar disk, which has dramatic consequences for diagnostics of temperature and density and therefore estimates of key plasma parameters such as the plasma {beta} and ion-electron collision rates.

  8. A PSF equalization technique for the Multi-Order Solar Extreme-ultraviolet Spectrograph (MOSES)

    NASA Astrophysics Data System (ADS)

    Atwood, Shane; Kankelborg, Charles

    2015-10-01

    The Multi-Order Solar Extreme Ultraviolet Spectrograph (MOSES) is a rocket-borne slitless imaging spectrometer, designed to observe He II (30.4 nm) emission in the solar transition region. This instrument forms three simultaneous images at spectral orders m=-1, 0, +1 over an extended field of view (FOV). A multi-layer coating on the grating and thin film filters in front of the detectors defines the instrument passband. Each image contains a unique combination of spectral and spatial information. Our overarching goal in analyzing these data is to estimate a spectral line profile at every point in the FOV. Each spectral order has different image geometry, and therefore different aberrations. Since the point spread function (PSF) differs between any two images, systematic errors are introduced when we use all three images together to invert for spectral line profiles. To combat this source of systematic error, we have developed a PSF equalization scheme. Determination of the image PSFs is impractical for several reasons, including changes that may occur due to vibration during both launch and recovery operations. We have therefore developed a strategy using only the solar images obtained during flight to generate digital filters that modify each image so that they have the same effective PSF. Generation of the PSF equalization filters does not require that the PSFs themselves be known. Our approach begins with the assumption that there are only two things that cause the power spectra of our images to differ: (1) aberrations; and (2) the FOV average spectral line profile, which is known in principle from an abundance of historical data. To validate our technique, we generate three synthetic images with three different PSFs. We compare PSF equalizations performed without knowledge of the PSF to corrections performed with that knowledge. Finally, we apply PSF equalization to solar images obtained in the 2006 MOSES flight and demonstrate the removal of artifacts.

  9. Overlying extreme-ultraviolet arcades preventing eruption of a filament observed by AIA/SDO

    SciTech Connect

    Chen, Huadong; Ma, Suli; Zhang, Jun

    2013-11-20

    Using the multi-wavelength data from the Atmospheric Imaging Assembly/Solar Dynamic Observatory (AIA/SDO) and the Sun Earth Connection Coronal and Heliospheric Investigation/Solar Terrestrial Relations Observatory (SECCHI/STEREO), we report a failed filament eruption in NOAA AR 11339 on 2011 November 3. The eruption was associated with an X1.9 flare, but without any coronal mass ejection (CME), coronal dimming, or extreme ultraviolet (EUV) waves. Some magnetic arcades above the filament were observed distinctly in EUV channels, especially in the AIA 94 Å and 131 Å wavebands, before and during the filament eruption process. Our results show that the overlying arcades expanded along with the ascent of the filament at first until they reached a projected height of about 49 Mm above the Sun's surface, where they stopped. The following filament material was observed to be confined by the stopped EUV arcades and not to escape from the Sun. After the flare, a new filament formed at the low corona where part of the former filament remained before its eruption. These results support that the overlying arcades play an important role in preventing the filament from successfully erupting outward. We also discuss in this paper the EUV emission of the overlying arcades during the flare. It is rare for a failed filament eruption to be associated with an X1.9 class flare, but not with a CME or EUV waves. Therefore, this study also provides valuable insight into the triggering mechanism of the initiation of CMEs and EUV waves.

  10. Solar Extreme Ultraviolet and X-ray Irradiance Measurements for Thermosphere and Ionosphere Studies (Invited)

    NASA Astrophysics Data System (ADS)

    Woods, T. N.; Caspi, A.; Chamberlin, P. C.; Eparvier, F. G.; Jones, A. R.; Sojka, J. J.; Solomon, S. C.; Viereck, R. A.

    2013-12-01

    The solar extreme ultraviolet (EUV: 10-120 nm) and soft X-ray (SXR: 0.1-10 nm) radiation is critical energy input for Earth's upper atmosphere above 80 km as a driver for photochemistry, ionosphere creation, temperature structure, and dynamics. Understanding the solar EUV and X-ray variations and their influences on Earth's atmosphere are important for myriad of space weather applications. The solar EUV and SXR spectral irradiances are currently being measured by NASA's Thermosphere, Ionosphere, Mesosphere, Energetics, and Dynamics (TIMED) Solar EUV Experiment (SEE), NASA's Solar Dynamics Observatory (SDO) EUV Variability Experiment (EVE), and NOAA's GOES X-Ray Sensor (XRS) and EUV Sensor (EUVS). The solar irradiance varies on all time scales, ranging from seconds to hours from solar flare events, to days from 27-day solar rotation, and to years and longer from 11-year solar cycle. The amount of variation is strongly wavelength dependent with smaller ~50% solar cycle variations seen in the EUV for transition region emissions and larger factor of 10 and more variations seen in the SXR for coronal emissions. These solar irradiance observations are expected to be continued and to overlap with NASA's future Global-scale Observations of the Limb and Disk (GOLD) and Ionospheric Connection (ICON) missions that focus on the study of the thermosphere and ionosphere. These current measurements are only broad band in the SXR, but there are plans to have new spectral SXR measurements from CubeSat missions that may also overlap with the GOLD and ICON missions.

  11. On the nature of the extreme-ultraviolet late phase of solar flares

    SciTech Connect

    Li, Y.; Ding, M. D.; Guo, Y.; Dai, Y.

    2014-10-01

    The extreme-ultraviolet (EUV) late phase of solar flares is a second peak of warm coronal emissions (e.g., Fe XVI) for many minutes to a few hours after the GOES soft X-ray peak. It was first observed by the EUV Variability Experiment on board the Solar Dynamics Observatory (SDO). The late-phase emission originates from a second set of longer loops (late-phase loops) that are higher than the main flaring loops. It is suggested to be caused by either additional heating or long-lasting cooling. In this paper, we study the role of long-lasting cooling and additional heating in producing the EUV late phase using the enthalpy based thermal evolution of loops model. We find that a long cooling process in late-phase loops can well explain the presence of the EUV late-phase emission, but we cannot exclude the possibility of additional heating in the decay phase. Moreover, we provide two preliminary methods based on the UV and EUV emissions from the Atmospheric Imaging Assembly on board SDO to determine whether or not additional heating plays a role in the late-phase emission. Using nonlinear force-free field modeling, we study the magnetic configuration of the EUV late phase. It is found that the late phase can be generated either in hot spine field lines associated with a magnetic null point or in large-scale magnetic loops of multipolar magnetic fields. In this paper, we also discuss why the EUV late phase is usually observed in warm coronal emissions and why the majority of flares do not exhibit an EUV late phase.

  12. Extending the path for efficient extreme ultraviolet sources for advanced nanolithography

    SciTech Connect

    Sizyuk, Tatyana; Hassanein, Ahmed

    2015-09-15

    Developing efficient light sources for extreme ultraviolet (EUV) lithography is one of the most important problems of high volume manufacturing (HVM) of the next generation computer chips. Critical components of this technology are continued to face challenges in the demanding performance for HVM. Current investigations of EUV and beyond EUV (BEUV) community are focused on the dual-pulse laser produced plasma (LPP) using droplets of mass-limited targets. Two main objectives as well as challenges in the optimization of these light sources are related to enhancement of the conversion efficiency (CE) of the source and increase components lifetime of the collector optical system. These require significant experimental and computer simulation efforts. These requirements call for fine detail analysis of various plasma physics processes involved in laser target interactions and their effects on source optimization. We continued to enhance our comprehensive HEIGHTS simulation package and upgrade our CMUXE laboratories to study and optimize the efficiency of LPP sources. Integrated modeling and experimental research were done to both benchmark simulation results and to make projections and realistic predictions of the development path for powerful EUVL devices for HVM requirements. We continued the detail analysis of dual-pulse laser systems using various laser wavelengths and delay times between the two pulses. We showed that the efficiency of EUV sources can be improved utilizing the higher harmonics of Nd:YAG laser for the prepulse and the first harmonics for the main pulse, while still having lower efficiency than the combination involving CO{sub 2} laser in the range of parameters studied in this case. The differences in optimization process as well as in the source characteristics for two combinations of laser wavelengths were analyzed based on details of atomic and hydrodynamics processes during the evolving plasma plumes.

  13. A chain of winking (oscillating) filaments triggered by an invisible extreme-ultraviolet wave

    SciTech Connect

    Shen, Yuandeng; Tian, Zhanjun; Zhao, Ruijuan; Ichimoto, Kiyoshi; Ishii, Takako T.; Shibata, Kazunari

    2014-05-10

    Winking (oscillating) filaments have been observed for many years. However, observations of successive winking filaments in one event have not yet been reported. In this paper, we present the observations of a chain of winking filaments and a subsequent jet that are observed right after the X2.1 flare in AR11283. The event also produced an extreme-ultraviolet (EUV) wave that has two components: an upward dome-like wave (850 km s{sup –1}) and a lateral surface wave (554 km s{sup –1}) that was very weak (or invisible) in imaging observations. By analyzing the temporal and spatial relationships between the oscillating filaments and the EUV waves, we propose that all the winking filaments and the jet were triggered by the weak (or invisible) lateral surface EUV wave. The oscillation of the filaments last for two or three cycles, and their periods, Doppler velocity amplitudes, and damping times are 11-22 minutes, 6-14 km s{sup –1}, and 25-60 minutes, respectively. We further estimate the radial component magnetic field and the maximum kinetic energy of the filaments, and they are 5-10 G and ∼10{sup 19} J, respectively. The estimated maximum kinetic energy is comparable to the minimum energy of ordinary EUV waves, suggesting that EUV waves can efficiently launch filament oscillations on their path. Based on our analysis results, we conclude that the EUV wave is a good agent for triggering and connecting successive but separated solar activities in the solar atmosphere, and it is also important for producing solar sympathetic eruptions.

  14. High-precision reflectometry of multilayer coatings for extreme ultraviolet lithography

    SciTech Connect

    Wedowski, M; Underwood, J H; Gullikson, E M; Bajt, S; Folta, J A; Kearney, P A; Montcalm, C; Spiller, E

    1999-12-29

    Synchrotron-based reflectometry is an important technique for the precise determination of optical properties of reflective multilayer coatings for Extreme Ultraviolet Lithography (EUVL). Multilayer coatings enable normal incidence reflectances of more than 65% in the wavelength range between 11 and 15 nm. In order to achieve high resolution and throughput of EUVL systems, stringent requirements not only apply to their mechanical and optical layout, but also apply to the optical properties of the multilayer coatings. Therefore, multilayer deposition on near-normal incidence optical surfaces of projection optics, condenser optics and reflective masks requires suitable high-precision metrology. Most important, due to their small bandpass on the order of only 0.5 nm, all reflective multilayer coatings in EUVL systems must be wavelength-matched to within {+-}0.05 nm. In some cases, a gradient of the coating thickness is necessary for wavelength matching at variable average angle of incidence in different locations on the optical surfaces. Furthermore, in order to preserve the geometrical figure of the optical substrates, reflective multilayer coatings need to be uniform to within 0.01 nm in their center wavelength. This requirement can only be fulfilled with suitable metrology, which provides a precision of a fraction of this value. In addition, for the detailed understanding and the further development of reflective multilayer coatings a precision in the determination of peak reflectances is desirable on the order of 0.1%. Substrates up to 200 mm in diameter and 15 kg in mass need to be accommodated. Above requirements are fulfilled at beamline 6.3.2 of the Advanced Light Source (ALS) in Berkeley. This beamline proved to be precise within 0.2% (ms) for reflectance and 0.002 nm (rms) for wavelength.

  15. Nonthermal phase transitions in semiconductors induced by a femtosecond extreme ultraviolet laser pulse

    NASA Astrophysics Data System (ADS)

    Medvedev, Nikita; Jeschke, Harald O.; Ziaja, Beata

    2013-01-01

    In this paper, we present a novel theoretical approach, which allows the study of nonequilibrium dynamics of both electrons and atoms/ions within free-electron laser excited semiconductors at femtosecond time scales. The approach consists of the Monte-Carlo method treating photoabsorption, high-energy-electron and core-hole kinetics and relaxation processes. Low-energy electrons localized within the valence and conduction bands of the target are treated with a temperature equation, including source terms, defined by the exchange of energy and particles with high-energy electrons and atoms. We follow the atomic motion with the molecular dynamics method on the changing potential energy surface. The changes of the potential energy surface and of the electron band structure are calculated at each time step with the help of the tight-binding method. Such a combination of methods enables investigation of nonequilibrium structural changes within materials under extreme ultraviolet (XUV) femtosecond irradiation. Our analysis performed for diamond irradiated with an XUV femtosecond laser pulse predicts for the first time in this wavelength regime the nonthermal phase transition from diamond to graphite. Similar to the case of visible light irradiation, this transition takes place within a few tens of femtoseconds and is caused by changes of the interatomic potential induced by ultrafast electronic excitations. It thus occurs well before the heating stimulated by electron-phonon coupling starts to play a role. This allows us to conclude that this transition is nonthermal and represents a general mechanism of the response of solids to ultrafast electron excitations.

  16. Extreme-ultraviolet beam-foil spectroscopy of highly ionized neon and argon. Doctoral thesis

    SciTech Connect

    Demarest, J.A.

    1986-08-01

    A study of the extreme-ultraviolet radiation emitted by ion beams of highly ionized neon and argon after passage through thin foils was conducted. A grazing-incidence spectrometer was equipped with a position-sensitive microchannel plate (MCP) detector, which improved the detection efficiency by two orders of magnitude. The position information of the MCP was determined to be linear over 90% of the 50-mm-wide detector. Spectra spanning regions of over 100 A were accumulated at a resolution of less than 1 A. A wavelength calibration based on a second order equation of spectrometer position was found to result in an accuracy of - 0.1 A. Over 40 transitions of Ne VIII, Ne IX, and Ne X were observed in the wavelength region from 350 to 30 A from n=2-3,4,5; n=3-4,5,6,7,8; n=4-6,7; and n=5-9. An intensity calibration of the detection system allowed the determination of the relative populations of n=3 states of Ne VIII and Ne IX. An overpopulation of states with low orbital angular momenta support electron-capture predictions by the first-order Born approximation. The argon beam-foil data confirmed the wavelength predictions of 30 previously unobserved transitions in the wavlength region from 355 to 25 A from n=2-2; n=3-4; n=4-5,6,7; and n=6-8. Lifetime determinations were made by the simultaneous measurement of 26 argon lines in the spectral region from 295-180 A. Many of the n=2-2 transitions agreed well with theory.

  17. Ionization and dissociation dynamics of vinyl bromide probed by femtosecond extreme ultraviolet transient absorption spectroscopy.

    PubMed

    Lin, Ming-Fu; Neumark, Daniel M; Gessner, Oliver; Leone, Stephen R

    2014-02-14

    Strong-field induced ionization and dissociation dynamics of vinyl bromide, CH2=CHBr, are probed using femtosecond extreme ultraviolet (XUV) transient absorption spectroscopy. Strong-field ionization is initiated with an intense femtosecond, near infrared (NIR, 775 nm) laser field. Femtosecond XUV pulses covering the photon energy range of 50-72 eV probe the subsequent dynamics by measuring the time-dependent spectroscopic features associated with transitions of the Br (3d) inner-shell electrons to vacancies in molecular and atomic valence orbitals. Spectral signatures are observed for the depletion of neutral C2H3Br, the formation of C2H3Br(+) ions in their ground (X̃) and first excited (Ã) states, the production of C2H3Br(++) ions, and the appearance of neutral Br ((2)P3/2) atoms by dissociative ionization. The formation of free Br ((2)P3/2) atoms occurs on a timescale of 330 ± 150 fs. The ionic à state exhibits a time-dependent XUV absorption energy shift of ∼0.4 eV within the time window of the atomic Br formation. The yield of Br atoms correlates with the yield of parent ions in the à state as a function of NIR peak intensity. The observations suggest that a fraction of vibrationally excited C2H3Br(+) (Ã) ions undergoes intramolecular vibrational energy redistribution followed by the C-Br bond dissociation. The C2H3Br(+) (X̃) products and the majority of the C2H3Br(++) ions are relatively stable due to a deeper potential well and a high dissociation barrier, respectively. The results offer powerful new insights about orbital-specific electronic processes in high field ionization, coupled vibrational relaxation and dissociation dynamics, and the correlation of valence hole-state location and dissociation in polyatomic molecules, all probed simultaneously by ultrafast table-top XUV spectroscopy.

  18. Analysis of Cassini UVIS Extreme and Far Ultraviolet Observations of Saturn’s Atmosphere

    NASA Astrophysics Data System (ADS)

    Parkinson, Christopher D.; Koskinen, Tommi; Gronoff, Guillaume; Yung, Yuk L.; Esposito, Larry

    2015-11-01

    The atmosphere of Saturn is mainly composed of H2 and neutral atomic helium. The study of He 584 Å and H Lyman-α brightnesses is interesting as the EUV and FUV (Extreme and Far Ultraviolet) planetary airglow have the potential to yield useful information about mixing and other important parameters in its thermosphere. Time variation, asymmetries, and polar enhancement of the airglow are also possible and analysis already performed using the public archived Cassini mission data sets have shown we can solve some of the outstanding problems associated with these phenomena for Saturn.Specifically, we have (1) examined epochal eddy mixing disparities in the Saturnian upper atmosphere and quantify temporal mixing variations that may have occurred in the upper atmosphere of Saturn, as may be evidenced in Cassini mission data, (2) quantified any enhanced mixing in the auroral regions of Saturn, and (3) performed a robust study of Saturnian H Lyman-α brightness with the view to discover any longitudinal H Lyman-α planetary asymmetry or “bulge” across the disc such as was discovered by Voyager at Jupiter, indicative of the distribution of atomic H and accounting for the observed flux and any variations from the normal temperature profile.We have analyzed Cassini UVIS EUV and FUV airglow data from Saturn using sophisticated photochemical and radiative transfer models to investigate unexplained differences in the dynamical processes operating within its upper atmosphere. Powerful analysis techniques allow us to extract information on atmospheric mixing, temperatures, and temporal changes due to the solar and seasonal cycles from the variations in distribution and intensity of airglow emissions that result. We report on results of these efforts to date.

  19. The extreme ultraviolet spectra of low-redshift radio-loud quasars

    NASA Astrophysics Data System (ADS)

    Punsly, Brian; Reynolds, Cormac; Marziani, Paola; O'Dea, Christopher P.

    2016-07-01

    This paper reports on the extreme ultraviolet (EUV) spectrum of three low-redshift (z ˜ 0.6) radio-loud quasars, 3C 95, 3C 57 and PKS 0405-123. The spectra were obtained with the Cosmic Origins Spectrograph of the Hubble Space Telescope. The bolometric thermal emission, Lbol, associated with the accretion flow is a large fraction of the Eddington limit for all of these sources. We estimate the long-term time-averaged jet power, overline{Q}, for the three sources. overline{Q}/L_{bol}, is shown to lie along the correlation of overline{Q}/L_{bol}, and αEUV found in previous studies of the EUV continuum of intermediate and high-redshift quasars, where the EUV continuum flux density between 1100 and 700 Å is defined by F_{ν } ˜ ν ^{-α _{EUV}}. The high Eddington ratios of the three quasars extend the analysis into a wider parameter space. Selecting quasars with high Eddington ratios has accentuated the statistical significance of the partial correlation analysis of the data. Namely, the correlation of overline{Q}/L_{bol} and αEUV is fundamental, and the correlation of overline{Q} and αEUV is spurious at a very high statistical significance level (99.8 per cent). This supports the regulating role of ram pressure of the accretion flow in magnetically arrested accretion models of jet production. In the process of this study, we use multifrequency and multiresolution Very Large Array radio observations to determine that one of the bipolar jets in 3C 57 is likely frustrated by galactic gas that keeps the jet from propagating outside the host galaxy.

  20. Spatial characterization of extreme ultraviolet plasmas generated by laser excitation of xenon gas targets

    NASA Astrophysics Data System (ADS)

    Kranzusch, Sebastian; Peth, Christian; Mann, Klaus

    2003-02-01

    At Laser-Laboratorium Göttingen laser-plasma sources were tested, which are going to be used for characterization of optical components and sensoric devices in the wavelength region from 11 to 13 nm. In all cases extreme ultraviolet (EUV) radiation is generated by focusing a Q-switched Nd:YAG laser into a pulsed gas puff target. By the use of xenon or oxygen as target gas, broadband as well as narrowband EUV radiation is obtained, respectively. Different types of valves and nozzles were tested in order to optimize the emitted radiation with respect to maximum EUV intensities, small source diameters, and positional stability. The investigation of these crucial source parameters was performed with specially designed EUV pinhole cameras, utilizing evaluation algorithms developed for standardized laser beam characterization. In addition, a rotatable pinhole camera was developed which allows both spatially and angular resolved monitoring of the soft x-ray emission characteristics. With the help of this camera a strong angular dependence of the EUV intensity was found. The data were compared with fluorescence measurements for visualization of the target gas jet. The experimental observations can be explained by reabsorption of the generated EUV radiation in the surrounding target gas, as supported by semiempirical model calculations based on the attenuation in the three-dimensional gas density according to Lambert-Beer's law. As a consequence of the presented investigations, an optimization of the EUV source with respect to intensity, plasma shape, and angular dependence is achieved, resulting in a spherical plasma of 200 μm diameter and a 50% increase of the EUV pulse energy.

  1. Observation of a Quasiperiodic Pulsation in Hard X-Ray, Radio, and Extreme-ultraviolet Wavelengths

    NASA Astrophysics Data System (ADS)

    Kumar, Pankaj; Nakariakov, Valery M.; Cho, Kyung-Suk

    2016-05-01

    We present a multiwavelength analysis of a quasiperiodic pulsation (QPP) observed in the hard X-ray (HXR), radio, and extreme-ultraviolet (EUV) channels during an M1.9 flare that occurred on 2011 September 23-24. The nonthermal HXR emission in 25-50 keV observed by RHESSI shows five distinct impulsive peaks of decaying amplitude with a period of about 3 minutes. A similar QPP was observed in the microwave emission recorded by the Nobeyama Radioheliograph and Polarimeter in the 2, 3.75, 9.4, and 17 GHz channels. Interestingly, the 3-minute QPP was also observed in the metric and decimetric radio frequencies (25-180, 245, 610 MHz) as repetitive type III bursts. Multiwavelength observations from the Solar Dynamics Observatory/Atmospheric Image Assembly, Hinode/SOT, and Solar TErrestrial RElations Observatory/SECCHI suggest a fan-spine topology at the eruption site, associated with the formation of a quasi-circular ribbon during the flare. A small filament was observed below the fan loops before the flare onset. The filament rose slowly and interacted with the ambient field. This behavior was followed by an untwisting motion of the filament. Two different structures of the filament showed an approximately 3-minute periodic alternate rotation in the clockwise and counterclockwise directions. The 3-minute QPP was found to highly correlate with 3-minute oscillations in a nearby sunspot. We suggest that the periodic reconnection (modulated either by a sunspot slow-mode wave or by an untwisting filament) at a magnetic null point most likely causes the repetitive particle acceleration, generating the QPP observed in HXR, microwave, and type III radio bursts.

  2. Profile reconstruction in extreme ultraviolet (EUV) scatterometry: modeling and uncertainty estimates

    NASA Astrophysics Data System (ADS)

    Gross, H.; Rathsfeld, A.; Scholze, F.; Bär, M.

    2009-10-01

    Scatterometry as a non-imaging indirect optical method in wafer metrology is also relevant to lithography masks designed for extreme ultraviolet lithography, where light with wavelengths in the range of 13 nm is applied. The solution of the inverse problem, i.e. the determination of periodic surface structures regarding critical dimensions (CD) and other profile properties from light diffraction patterns, is incomplete without knowledge of the uncertainties associated with the reconstructed parameters. The numerical simulation of the diffraction process for periodic 2D structures can be realized by the finite element solution of the two-dimensional Helmholtz equation. The inverse problem can be formulated as a nonlinear operator equation in Euclidean space. The operator maps the sought mask parameters to the efficiencies of diffracted plane wave modes. We employ a Gauß-Newton type iterative method to solve this operator equation and end up minimizing the deviation of the measured efficiency or phase shift values from the calculated ones. We apply our reconstruction algorithm for the measurement of a typical EUV mask composed of TaN absorber lines of about 80 nm height, a period in the range of 420 nm-840 nm, and with an underlying MoSi-multilayer stack of 300 nm thickness. Clearly, the uncertainties of the reconstructed geometric parameters essentially depend on the uncertainties of the input data and can be estimated by various methods. We apply a Monte Carlo procedure and an approximative covariance method to evaluate the reconstruction algorithm. Finally, we analyze the influence of uncertainties in the widths of the multilayer stack by the Monte Carlo method.

  3. Extending the path for efficient extreme ultraviolet sources for advanced nanolithography

    NASA Astrophysics Data System (ADS)

    Sizyuk, Tatyana; Hassanein, Ahmed

    2015-09-01

    Developing efficient light sources for extreme ultraviolet (EUV) lithography is one of the most important problems of high volume manufacturing (HVM) of the next generation computer chips. Critical components of this technology are continued to face challenges in the demanding performance for HVM. Current investigations of EUV and beyond EUV (BEUV) community are focused on the dual-pulse laser produced plasma (LPP) using droplets of mass-limited targets. Two main objectives as well as challenges in the optimization of these light sources are related to enhancement of the conversion efficiency (CE) of the source and increase components lifetime of the collector optical system. These require significant experimental and computer simulation efforts. These requirements call for fine detail analysis of various plasma physics processes involved in laser target interactions and their effects on source optimization. We continued to enhance our comprehensive HEIGHTS simulation package and upgrade our CMUXE laboratories to study and optimize the efficiency of LPP sources. Integrated modeling and experimental research were done to both benchmark simulation results and to make projections and realistic predictions of the development path for powerful EUVL devices for HVM requirements. We continued the detail analysis of dual-pulse laser systems using various laser wavelengths and delay times between the two pulses. We showed that the efficiency of EUV sources can be improved utilizing the higher harmonics of Nd:YAG laser for the prepulse and the first harmonics for the main pulse, while still having lower efficiency than the combination involving CO2 laser in the range of parameters studied in this case. The differences in optimization process as well as in the source characteristics for two combinations of laser wavelengths were analyzed based on details of atomic and hydrodynamics processes during the evolving plasma plumes.

  4. Absolute Rayleigh scattering cross sections of gases and freons of stratospheric interest in the visible and ultraviolet regions

    NASA Technical Reports Server (NTRS)

    SHARDANAND; Rao, A. D. P.

    1977-01-01

    The laboratory measurements of absolute Rayleigh scattering cross sections as a function wavelength are reported for gas molecules He, Ne, Ar, N2, H2, O2, CO2, CH4 and for vapors of most commonly used freons CCl2F2, CBrF3, CF4, and CHClf2. These cross sections are determined from the measurements of photon scattering at an angle of 54 deg 44 min which yield the absolute values independent of the value of normal depolarization ratios. The present results show that in the spectral range 6943-3638A deg, the values of the Rayleigh scattering cross section can be extrapolated from one wavelength to the other using 1/lambda (4) law without knowing the values of the polarizabilities. However, such an extrapolation can not be done in the region of shorter wavelengths.

  5. Absolute atomic oxygen and nitrogen densities in radio-frequency driven atmospheric pressure cold plasmas: Synchrotron vacuum ultra-violet high-resolution Fourier-transform absorption measurements

    SciTech Connect

    Niemi, K.; O'Connell, D.; Gans, T.; Oliveira, N. de; Joyeux, D.; Nahon, L.; Booth, J. P.

    2013-07-15

    Reactive atomic species play a key role in emerging cold atmospheric pressure plasma applications, in particular, in plasma medicine. Absolute densities of atomic oxygen and atomic nitrogen were measured in a radio-frequency driven non-equilibrium plasma operated at atmospheric pressure using vacuum ultra-violet (VUV) absorption spectroscopy. The experiment was conducted on the DESIRS synchrotron beamline using a unique VUV Fourier-transform spectrometer. Measurements were carried out in plasmas operated in helium with air-like N{sub 2}/O{sub 2} (4:1) admixtures. A maximum in the O-atom concentration of (9.1 {+-} 0.7) Multiplication-Sign 10{sup 20} m{sup -3} was found at admixtures of 0.35 vol. %, while the N-atom concentration exhibits a maximum of (5.7 {+-} 0.4) Multiplication-Sign 10{sup 19} m{sup -3} at 0.1 vol. %.

  6. Caffeine citrate treatment for extremely premature infants with apnea: population pharmacokinetics, absolute bioavailability, and implications for therapeutic drug monitoring.

    PubMed

    Charles, Bruce G; Townsend, Sarah R; Steer, Peter A; Flenady, Vicki J; Gray, Peter H; Shearman, Andrew

    2008-12-01

    The objective of this study was to develop a population model of the pharmacokinetics (PK) of caffeine after orogastric or intravenous administration to extremely premature neonates with apnea of prematurity who were to undergo extubation from ventilation. Infants of gestational age <30 weeks were randomly allocated to receive maintenance caffeine citrate dosing of either 5 or 20 mg/kg/d. Four blood samples were drawn at prerandomized times from each infant during caffeine treatment. Serum caffeine was assayed by enzyme-multiplied immunoassay technique. Concentration data (431 samples, median: 4 per subject) were obtained from 110 (52 male) infants of mean birth weight of 1009 g, current mean weight (WT) of 992 g, mean gestational age of 27.6 weeks, and mean postnatal age (PNA) of 12 days. Of 1022 doses given, 145 were orogastric, permitting estimation of absolute bioavailability. A 1-compartment model with first-order absorption was fitted to the data in NONMEM. Patient characteristics were screened (P < 0.01) in nested models for pharmacokinetic influence. Model stability was assessed by nonparametric bootstrapping. Clearance (CL) increased nonlinearly with increasing PNA, whereas volume of distribution (Vd) increased linearly with WT, according to the following allometric models: CL (L/h) = 0.167 (WT/70) (PNA/12); Vd (L) = 58.7 (WT/70). The mean elimination half-life was 101. Interindividual variability (IIV) of CL and Vd was 18.8 % and 22.3 %, respectively. Interoccasion variability (IOV) of CL and Vd was 35.1% and 11.1%, respectively. This study established that the elimination of caffeine was severely depressed in extremely premature infants but increased nonlinearly after birth up to age 6 weeks. Caffeine was completely absorbed, which has favorable implications for switching between intravenous and orogastric routes. The interoccasion variability about CL was twice the interindividual variability, which, among other factors, indicates that routine serum

  7. X ray, extreme and far ultraviolet optical thin films for space applications

    NASA Technical Reports Server (NTRS)

    Zukic, Muamer; Torr, Douglas G.; Kim, Jongmin

    1993-01-01

    Far and extreme ultraviolet optical thin film filters find many uses in space astronomy, space astrophysics, and space aeronomy. Spacebased spectrographs are used for studying emission and absorption features of the earth, planets, sun, stars, and the interstellar medium. Most of these spectrographs use transmission or reflection filters. This requirement has prompted a search for selective filtering coatings with high throughput in the FUV and EUV spectral region. Important progress toward the development of thin film filters with improved efficiency and stability has been made in recent years. The goal for this field is the minimization of absorption to get high throughput and enhancement of wavelength selection. The Optical Aeronomy Laboratory (OAL) at the University of Alabama in Huntsville has recently developed the technology to determine optical constants of bulk and film materials for wavelengths extending from x-rays (0.1 nm) to the FUV (200 nm), and several materials have been identified that were used for designs of various optical devices which previously have been restricted to space application in the visible and near infrared. A new design concept called the Pi-multilayer was introduced and applied to the design of optical coatings for wavelengths extending from x-rays to the FUV. Section 3 of this report explains the Pi-multilayer approach and demonstrates its application for the design and fabrication of the FUV coatings. Two layer Pi-stacks have been utilized for the design of reflection filters in the EUV wavelength range from 70 - 100 nm. In order to eliminate losses due to the low reflection of the imaging optics and increase throughput and out-of-band rejection of the EUV instrumentation we introduced a self-filtering camera concept. In the FUV region, MgF2 and LiF crystals are known to be birefringent. Transmission polarizers and quarterwave retarders made of MgF2 or LiF crystals are commercially available but the performances are poor. New

  8. Sensitivity enhancement of chemically amplified resists and performance study using extreme ultraviolet interference lithography

    NASA Astrophysics Data System (ADS)

    Buitrago, Elizabeth; Nagahara, Seiji; Yildirim, Oktay; Nakagawa, Hisashi; Tagawa, Seiichi; Meeuwissen, Marieke; Nagai, Tomoki; Naruoka, Takehiko; Verspaget, Coen; Hoefnagels, Rik; Rispens, Gijsbert; Shiraishi, Gosuke; Terashita, Yuichi; Minekawa, Yukie; Yoshihara, Kosuke; Oshima, Akihiro; Vockenhuber, Michaela; Ekinci, Yasin

    2016-07-01

    Extreme ultraviolet lithography (EUVL, λ=13.5 nm) is the most promising candidate to manufacture electronic devices for future technology nodes in the semiconductor industry. Nonetheless, EUVL still faces many technological challenges as it moves toward high-volume manufacturing (HVM). A key bottleneck from the tool design and performance point of view has been the development of an efficient, high-power EUV light source for high throughput production. Consequently, there has been extensive research on different methodologies to enhance EUV resist sensitivity. Resist performance is measured in terms of its ultimate printing resolution, line width roughness (LWR), sensitivity [S or best energy (BE)], and exposure latitude (EL). However, there are well-known fundamental trade-off relationships (line width roughness, resolution and sensitivity trade-off) among these parameters for chemically amplified resists (CARs). We present early proof-of-principle results for a multiexposure lithography process that has the potential for high sensitivity enhancement without compromising other important performance characteristics by the use of a "Photosensitized Chemically Amplified Resist™" (PSCAR™). With this method, we seek to increase the sensitivity by combining a first EUV pattern exposure with a second UV-flood exposure (λ=365 nm) and the use of a PSCAR. In addition, we have evaluated over 50 different state-of-the-art EUV CARs. Among these, we have identified several promising candidates that simultaneously meet sensitivity, LWR, and EL high-performance requirements with the aim of resolving line space (L/S) features for the 7- and 5-nm logic node [16- and 13-nm half-pitch (HP), respectively] for HVM. Several CARs were additionally found to be well resolved down to 12- and 11-nm HP with minimal pattern collapse and bridging, a remarkable feat for CARs. Finally, the performance of two negative tone state-of-the-art alternative resist platforms previously investigated

  9. Studies of extreme ultraviolet emission from laser produced plasmas, as sources for next generation lithography

    NASA Astrophysics Data System (ADS)

    Cummins, Thomas

    The work presented in this thesis is primarily concerned with the optimisation of extreme ultraviolet (EUV) photoemission around 13.5 nm, from laser produced tin (Sn) plasmas. EUV lithography has been identified as the leading next generation technology to take over from the current optical lithography systems, due to its potential of printing smaller feature sizes on integrated circuits. Many of the problems hindering the implementation of EUV lithography for high volume manufacturing have been overcome during the past 20 years of development. However, the lack of source power is a major concern for realising EUV lithography and remains a major roadblock that must be overcome. Therefore in order to optimise and improve the EUV emission from Sn laser plasma sources, many parameters contributing to the make-up of an EUV source are investigated. Chapter 3 presents the results of varying several different experimental parameters on the EUV emission from Sn laser plasmas. Several of the laser parameters including the energy, gas mixture, focusing lens position and angle of incidence are changed, while their effect on the EUV emission is studied. Double laser pulse experiments are also carried out by creating plasma targets for the main laser pulse to interact with. The resulting emission is compared to that of a single laser pulse on solid Sn. Chapter 4 investigates tailoring the CO2 laser pulse duration to improve the efficiency of an EUV source set-up. In doing so a new technique for shortening the time duration of the pulse is described. The direct effects of shortening the CO2 laser pulse duration on the EUV emission from Sn are then studied and shown to improve the efficiency of the source. In Chapter 5 a new plasma target type is studied and compared to the previous dual laser experiments. Laser produced colliding plasma jet targets form a new plasma layer, with densities that can be optimised for re-heating with the main CO2 laser pulse. Chapter 6 will present

  10. Mask characterization for critical dimension uniformity budget breakdown in advanced extreme ultraviolet lithography

    NASA Astrophysics Data System (ADS)

    Nikolsky, Peter; Strolenberg, Chris; Nielsen, Rasmus; Nooitgedacht, Tjitte; Davydova, Natalia; Yang, Greg; Lee, Shawn; Park, Chang-Min; Kim, Insung; Yeo, Jeong-Ho

    2013-04-01

    As the International Technology Roadmap for Semiconductors critical dimension uniformity (CDU) specification shrinks, semiconductor companies need to maintain a high yield of good wafers per day and high performance (and hence market value) of finished products. This cannot be achieved without continuous analysis and improvement of on-product CDU as one of the main drivers for process control and optimization with better understanding of main contributors from the litho cluster: mask, process, metrology and scanner. We will demonstrate a study of mask CDU characterization and its impact on CDU Budget Breakdown (CDU BB) performed for advanced extreme ultraviolet (EUV) lithography with 1D (dense lines) and 2D (dense contacts) feature cases. We will show that this CDU contributor is one of the main differentiators between well-known ArFi and new EUV CDU budgeting principles. We found that reticle contribution to intrafield CDU should be characterized in a specific way: mask absorber thickness fingerprints play a role comparable with reticle CDU in the total reticle part of the CDU budget. Wafer CD fingerprints, introduced by this contributor, may or may not compensate variations of mask CDs and hence influence on total mask impact on intrafield CDU at the wafer level. This will be shown on 1D and 2D feature examples. Mask stack reflectivity variations should also be taken into account: these fingerprints have visible impact on intrafield CDs at the wafer level and should be considered as another contributor to the reticle part of EUV CDU budget. We also observed mask error enhancement factor (MEEF) through field fingerprints in the studied EUV cases. Variations of MEEF may play a role towards the total intrafield CDU and may need to be taken into account for EUV lithography. We characterized MEEF-through-field for the reviewed features, with results herein, but further analysis of this phenomenon is required. This comprehensive approach to quantifying the mask part of

  11. TWO TYPES OF EXTREME-ULTRAVIOLET BRIGHTENINGS IN AR 10926 OBSERVED BY HINODE/EIS

    SciTech Connect

    Lee, K.-S.; Moon, Y.-J.; Choe, G. S.; Kim, Sujin; Cho, Kyung-Suk; Imada, S.

    2011-07-20

    We have investigated seven extreme-ultraviolet (EUV) brightenings in the active region AR 10926 on 2006 December 2 observed by the EUV Imaging Spectrometer on board the Hinode spacecraft. We have determined their Doppler velocities and non-thermal velocities from 15 EUV spectral lines (log T = 4.7 - 6.4) by fitting each line profile to a Gaussian function. The Doppler velocity maps for different temperatures are presented to show the height dependence of the Doppler shifts. It is found that the active region brightenings show two distinct Doppler shift patterns. The type 1 brightening shows a systematic increase of Doppler velocity from -68 km s{sup -1} (strong blueshift) at log T = 4.7 to -2 km s{sup -1} (weak blueshift) at log T = 6.4, while the type 2 brightenings have Doppler velocities in the range from -20 km s{sup -1} to 20 km s{sup -1}. The type 1 brightening point is considered to sit in an upward reconnection outflow whose speed decreases with height. In both types of brightenings, the non-thermal velocity is found to be significantly enhanced at log T = 5.8 compared to the background region. We have also determined electron densities from line ratios and derived temperatures from emission measure loci using the CHIANTI atomic database. The electron densities of all brightenings are comparable to typical values in active regions (log N{sub e} = 9.9-10.4). The emission measure loci plots indicate that these brightenings should be multi-thermal whereas the background is isothermal. The differential emission measure as a function of temperature shows multiple peaks in the EUV brightening regions, while it has only a single peak (log T = 6.0) in the background region. Using Michelson Doppler Imager magnetograms, we have found that the type 1 brightening is associated with a canceling magnetic feature with a flux canceling rate of 2.4 x 10{sup 18} Mx hr{sup -1}. We also found the canceling magnetic feature and chromospheric brightenings in the type 1

  12. Extreme Ultraviolet Late-Phase Flares: Before and During the Solar Dynamics Observatory Mission

    NASA Astrophysics Data System (ADS)

    Woods, Thomas N.

    2014-09-01

    The solar extreme-ultraviolet (EUV) observations from the Solar Dynamics Observatory (SDO) have revealed interesting characteristics of warm coronal emissions, such as Fe xvi 335 Å emission, which peak soon after the hot coronal X-ray emissions peak during a flare and then sometimes peak for a second time hours after the X-ray flare peak. This flare type, with two warm coronal emission peaks but only one X-ray peak, has been named the EUV late phase (Woods et al., Astrophys. J. 739, 59, 2011). These flares have the distinct properties of i) having a complex magnetic-field structure with two initial sets of coronal loops, with one upper set overlaying a lower set, ii) having an eruptive flare initiated in the lower set and disturbing both loop sets, iii) having the hot coronal emissions emitted only from the lower set in conjunction with the X-ray peak, and iv) having the first peak of the warm coronal emissions associated with the lower set and its second peak emitted from the upper set many minutes to hours after the first peak and without a second X-ray enhancement. The disturbance of the coronal loops by the eruption is at about the same time, but the relaxation and cooling down of the heated coronal loops during the post-flare reconnections have different time scales with the longer, upper loops being significantly delayed from the lower loops. The difference in these cooling time scales is related to the difference between the two peak times of the warm coronal emission and is also apparent in the decay profile of the X-ray emissions having two distinct decays, with the first decay slope being steeper (faster) and the delayed decay slope being smaller (slower) during the time of the warm-coronal-emission second peak. The frequency and relationship of the EUV late-phase decay times between the Fe xvi 335 Å two flare peaks and X-ray decay slopes are examined using three years of SDO/ EUV Variability Experiment (EVE) data, and the X-ray dual-decay character is

  13. The solar extreme ultra-violet corona: Resolved loops and the unresolved active region corona

    NASA Astrophysics Data System (ADS)

    Cirtain, Jonathan Wesley

    In this work, physical characteristics of the solar corona as observed in the Extreme Ultra-Violet (EUV) regime are investigated. The focus will be the regions of intense EUV radiation generally found near the locations of sunspots. These regions are commonly called active regions. Multiple space- based observing platforms have been deployed in the last decade; it is possible to use several of these observatories in combination to develop a more complete picture of the solar corona. Joint Observing Program 146 was created to collect spectroscopic intensities using the Coronal Diagnostic Spectrometer on Solar and Heliospheric Observatory and EUV images using NASA's Transition Region and Coronal Explorer. The emission line intensities are analyzed to develop an understanding of the temperature and density of the active region coronal plasma. However, the performance of the CDS instrument in the spatial and temporal domains is limited and to compensate for these limitations, data collected by the TRACE instrument provide a high spatial and temporal resolution set of observations. One of the most exciting unsolved problems in solar astrophysics is to understand why the corona maintains a temperature roughly two orders of magnitude higher than the underlying material. A detailed investigation of the coronal emission has provided constraints on models of the heating mechanism, since the temperature, density and evolution of emission rates for multiple ionic species are indicative of the mechanism(s) working to heat the corona. The corona appears to consist of multiple unresolved structures as well as resolved active region structures, called coronal loops. The purpose of the present work is to determine the characteristics of the unresolved background corona. Using the characterizations of the coronal unresolved background, results for loops after background subtraction are also presented. This work demonstrates the magnitude of the unresolved coronal emission with

  14. Compensation methods using a new model for buried defects in extreme ultraviolet lithography masks

    NASA Astrophysics Data System (ADS)

    Clifford, Chris H.; Chan, Tina T.; Neureuther, Andrew R.; Li, Ying; Peng, Danping; Pang, Linyong

    2010-09-01

    A new method for predicting the reflection from an extreme ultraviolet (EUV) multilayer is described which when implemented into the new Defect Printability Simulator (DPS) can calculate the image produced by an EUV mask with a buried defect several orders of magnitude faster than the finite difference time domain (FDTD). A new buried defect compensation method is also demonstrated to correct the in focus image of a line space pattern containing a buried defect. The new multilayer model accounts for the disruption of the magnitude and phase of the reflected field from an EUV multilayer defect. It does this by sampling the multilayer on a non-uniform grid and calculating the analytic complex local reflection coefficient at each point. After this step, the effect of the optical path difference due to the surface defect profile is added to the total reflected field to accurately predict the reflected magnitude and phase at all points on the multilayer surface. The accuracy of the new multilayer model and the full DPS simulator is verified by comparisons to FDTD simulations. The largest difference between the two methods was 0.8nm for predicting the CD change due to a buried defect through focus. This small difference is within the margin of error for FDTD simulations of EUV multilayers. The runtime of DPS is compared to extrapolated FDTD runtimes for many simulation domain sizes and DPS is 4-5 orders of magnitude faster for all cases. For example, DPS can calculate the reflected image from a 1μm x 1μm mask area in less than 30 seconds on a single processor. FDTD would take a month on four processors. The new compensation strategy demonstrated in this work is able to remove all CD error in the simulated image due to a buried defect in a 22nm dense line space pattern. The method is iterative and a full DPS simulation is run for every iteration. After each simulation, the absorber pattern is adjusted based on the difference of the thresholded target image and

  15. Determination of plasma temperatures and luminosities using multiple extreme-ultraviolet and X-ray filters

    NASA Technical Reports Server (NTRS)

    Wood, Brian E.; Brown, Alexander; Linsky, Jeffrey L.

    1995-01-01

    We carefully examine the techniques used to infer temperatures of stellar coronal plasmas from the count rates of several broadband instruments in the X-ray and extreme-ultraviolet spectral ranges. In particular, we determine to what extent temperatures can be constrained and the corresponding uncertainties in the luminosities and emission measures lowered by fitting simultaneously count rates from the Einstein imaging proportional counter (IPC), the ROSAT Position Sensitive Proportional Counter (PSPC), the ROSAT Wide Field Camera (WFC) (both filters), and the EXOSAT Low Energy Telescope (LET) with the 3-Lex filter. We use published plasma emissivities with solar photospheric abundances. Since it has been found that single-temperature plasmas do not fit IPC data well, we assume a two-temperature plasma model. We find that, even with count rates from all of the above filters and overly optimistic error estimates, it is still not possible to determine a unique two-temperature solution. However, since the use of count rates from many filters can reduce substantially the number of possible solutions, temperature solutions determined by other means can be tested. We carry out such an analysis on a set of 18 nearby late-type stars to determine possible two-temperature solutions using multifilter photometry, and we compare these results with the temperature solutions derived by Schmitt et al. (1990) using IPC spectral data. In general, the two-temperature fits derived from the IPC spectral data are inconsistent with our results, with our data implying that, for many stars, the two temperatures derived by the IPC may be too low by about a factor of 2. The EXOSAT transmission grating Spectrometer (TGS) spectra of capella and sigma(exp 2) CrB support this conclusion. For Procyon and 70 Oph, though, the presence of a temperature component cooler than a million degress (not detected by the IPC) is deduced. While our analysis suggests the existence of more than one temperature

  16. Comparison of solar radio and extreme ultraviolet synoptic limb charts during the present solar maximum

    NASA Astrophysics Data System (ADS)

    Oliveira e Silva, A. J.; Selhorst, C. L.; Simões, P. J. A.; Giménez de Castro, C. G.

    2016-08-01

    Aims: The present solar cycle is particular in many aspects: it had a delayed rising phase, it is the weakest of the last 100 yrs, and it presents two peaks separated by more than one year. To understand the impact of these characteristics on the solar chromosphere and coronal dynamics, images from a wide wavelength range are needed. In this work we use the 17 GHz radio continuum, which is formed in the upper chromosphere and the extreme ultraviolet (EUV) lines 304 and 171 Å, that come from the transition region (He ii, T ~ 6-8 × 104 K) and the corona (Fe IX, X, T ~ 106 K), respectively.We extend upon a previous similar analysis, and compare the mean equatorial and polar brightening behavior at radio and EUV wavelengths during the maximum of the present solar cycle, covering the period between 2010 and 2015. Methods: We analyze daily images at 304 and 171 Å obtained by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO). The 17 GHz maps were obtained by the Nobeyama Radioheliograph (NoRH). To construct synoptic limb charts, we calculated the mean emission of delimited limb areas with 100'' wide and angular separation of 5°. Results: At the equatorial region, the results show a hemispheric asymmetry of the solar activity. The northern hemisphere dominance is coincident with the first sunspot number peak, whereas the second peak occurs concurrently with the increase in the activity at the south. The polar emission reflects the presence of coronal holes at both EUV wavelengths, moreover, the 17 GHz polar brightenings can be associated with the coronal holes. Until 2013, both EUV coronal holes and radio polar brightenings were more predominant at the south pole.Since then they have not been apparent in the north, but thus appear in the beginning of 2015 in the south as observed in the synoptic charts. Conclusions: This work strengthens the association between coronal holes and the 17 GHz polar brightenings as it is evident in the

  17. Ionization and dissociation dynamics of vinyl bromide probed by femtosecond extreme ultraviolet transient absorption spectroscopy

    SciTech Connect

    Lin, Ming-Fu; Neumark, Daniel M.; Gessner, Oliver; Leone, Stephen R.

    2014-02-14

    Strong-field induced ionization and dissociation dynamics of vinyl bromide, CH{sub 2}=CHBr, are probed using femtosecond extreme ultraviolet (XUV) transient absorption spectroscopy. Strong-field ionization is initiated with an intense femtosecond, near infrared (NIR, 775 nm) laser field. Femtosecond XUV pulses covering the photon energy range of 50-72 eV probe the subsequent dynamics by measuring the time-dependent spectroscopic features associated with transitions of the Br (3d) inner-shell electrons to vacancies in molecular and atomic valence orbitals. Spectral signatures are observed for the depletion of neutral C{sub 2}H{sub 3}Br, the formation of C{sub 2}H{sub 3}Br{sup +} ions in their ground (X{sup ~}) and first excited (A{sup ~}) states, the production of C{sub 2}H{sub 3}Br{sup ++} ions, and the appearance of neutral Br ({sup 2}P{sub 3/2}) atoms by dissociative ionization. The formation of free Br ({sup 2}P{sub 3/2}) atoms occurs on a timescale of 330 ± 150 fs. The ionic A{sup ~} state exhibits a time-dependent XUV absorption energy shift of ∼0.4 eV within the time window of the atomic Br formation. The yield of Br atoms correlates with the yield of parent ions in the A{sup ~} state as a function of NIR peak intensity. The observations suggest that a fraction of vibrationally excited C{sub 2}H{sub 3}Br{sup +} (A{sup ~}) ions undergoes intramolecular vibrational energy redistribution followed by the C–Br bond dissociation. The C{sub 2}H{sub 3}Br{sup +} (X{sup ~}) products and the majority of the C{sub 2}H{sub 3}Br{sup ++} ions are relatively stable due to a deeper potential well and a high dissociation barrier, respectively. The results offer powerful new insights about orbital-specific electronic processes in high field ionization, coupled vibrational relaxation and dissociation dynamics, and the correlation of valence hole-state location and dissociation in polyatomic molecules, all probed simultaneously by ultrafast table-top XUV spectroscopy.

  18. Progress in coherent lithography using table-top extreme ultraviolet lasers

    NASA Astrophysics Data System (ADS)

    Li, Wei

    Nanotechnology has drawn a wide variety of attention as interesting phenomena occurs when the dimension of the structures is in the nanometer scale. The particular characteristics of nanoscale structures had enabled new applications in different fields in science and technology. Our capability to fabricate these nanostructures routinely for sure will impact the advancement of nanoscience. Apart from the high volume manufacturing in semiconductor industry, a small-scale but reliable nanofabrication tool can dramatically help the research in the field of nanotechnology. This dissertation describes alternative extreme ultraviolet (EUV) lithography techniques which combine table-top EUV laser and various cost-effective imaging strategies. For each technique, numerical simulations, system design, experiment result and its analysis will be presented. In chapter II, a brief review of the main characteristics of table-top EUV lasers will be addressed concentrating on its high power and large coherence radius that enable the lithography application described herein. The development of a Talbot EUV lithography system which is capable of printing 50nm half pitch nanopatterns will be illustrated in chapter III. A detailed discussion of its resolution limit will be presented followed by the development of X-Y-Z positioning stage, the fabrication protocol for diffractive EUV mask, and the pattern transfer using self- developed ion beam etching, and the dose control unit. In addition, this dissertation demonstrated the capability to fabricate functional periodic nanostructures using Talbot EUV lithography. After that, resolution enhancement techniques like multiple exposure, displacement Talbot EUV lithography, fractional Talbot EUV lithography, and Talbot lithography using 18.9nm amplified spontaneous emission laser will be demonstrated. Chapter IV will describe a hybrid EUV lithography which combines the Talbot imaging and interference lithography rendering a high resolution

  19. ZnO quantum dot-doped graphene/h-BN/GaN-heterostructure ultraviolet photodetector with extremely high responsivity

    NASA Astrophysics Data System (ADS)

    Lu, Yanghua; Wu, Zhiqian; Xu, Wenli; Lin, Shisheng

    2016-12-01

    A ZnO quantum dot photo-doped graphene/h-BN/GaN-heterostructure ultraviolet photodetector with extremely high responsivity of more than 1915 A W-1 and detectivity of more than 1.02 × 1013 Jones (Jones = cm Hz1/2 W-1) has been demonstrated. The interfaced h-BN layer increases the barrier height at the graphene/GaN heterojunction, which decreases the dark current and improves the on/off current ratio of the device. The photo-doping effect increases the barrier height and carrier concentration at the graphene/h-BN/GaN heterojunction, thus the responsivity is improved from 1473 A W-1 to 1915 A W-1 and the detectivity is improved from 5.8 × 1012 to 1.0 × 1013 Jones. Moreover, all of the responsivity and detectivity values are the highest values among all the graphene-based ultraviolet photodetectors.

  20. Extreme ultraviolet ionization of pure He nanodroplets: Mass-correlated photoelectron imaging, Penning ionization, and electron energy-loss spectra

    SciTech Connect

    Buchta, D.; Stienkemeier, F.; Mudrich, M.; Krishnan, S. R.; Moshammer, R.; Brauer, N. B.; Drabbels, M.; O’Keeffe, P.; Coreno, M.; Devetta, M.; Di Fraia, M.; Callegari, C.; Richter, R.; Prince, K. C.; Ullrich, J.

    2013-08-28

    The ionization dynamics of pure He nanodroplets irradiated by Extreme ultraviolet radiation is studied using Velocity-Map Imaging PhotoElectron-PhotoIon COincidence spectroscopy. We present photoelectron energy spectra and angular distributions measured in coincidence with the most abundant ions He{sup +}, He{sub 2}{sup +}, and He{sub 3}{sup +}. Surprisingly, below the autoionization threshold of He droplets, we find indications for multiple excitation and subsequent ionization of the droplets by a Penning-like process. At high photon energies we observe inelastic collisions of photoelectrons with the surrounding He atoms in the droplets.

  1. Characterization of a vacuum-arc discharge in tin vapor using time-resolved plasma imaging and extreme ultraviolet spectrometry.

    PubMed

    Kieft, E R; van der Mullen, J J A M; Kroesen, G M W; Banine, V; Koshelev, K N

    2005-02-01

    Discharge sources in tin vapor have recently been receiving increased attention as candidate extreme ultraviolet (EUV) light sources for application in semiconductor lithography, because of their favorable spectrum near 13.5 nm. In the ASML EUV laboratory, time-resolved pinhole imaging in the EUV and two-dimensional imaging in visible light have been applied for qualitative characterization of the evolution of a vacuum-arc tin vapor discharge. An EUV spectrometer has been used to find the dominant ionization stages of tin as a function of time during the plasma evolution of the discharge.

  2. Modification of magnetic properties of Pt/Co/Pt trilayers driven by nanosecond pulses of extreme ultraviolet irradiation

    NASA Astrophysics Data System (ADS)

    Sveklo, I.; Kurant, Z.; Bartnik, A.; Klinger, D.; Sobierajski, R.; Wawro, A.; Kisielewski, J.; Tekielak, M.; Maziewski, A.

    2017-01-01

    An irreversible rotation of magnetization from in-plane to an out-of-plane direction was induced in Pt/Co/Pt epitaxial trilayers by single and multiple pulses of extreme ultraviolet (EUV) irradiations. The radial dependence of remanence, coercivity and saturation fields across the irradiated spots was studied with the help of magneto-optical techniques for the samples with various Co and Pt buffer layer thicknesses. The sample surface and magnetic ordering were investigated using atomic force and magnetic force microscopies. Based on magnetic and morphological changes, the residual stress after thermoplastic deformation in the spot area is discussed as a reason for the observed transformation.

  3. Polarization effects in two-photon nonresonant ionization of argon with extreme-ultraviolet and infrared femtosecond pulses

    SciTech Connect

    O'Keeffe, P.; Lopez-Martens, R.; Mauritsson, J.; Johansson, A.; L'Huillier, A.; Veniard, V.; Taieeb, R.; Maquet, A.; Meyer, M.

    2004-05-01

    We report the results of experimental and theoretical investigations of the two-color, two-photon ionization of Ar atoms, using femtosecond pulses of infrared laser radiation in combination with its extreme-ultraviolet harmonics. It is shown that the intensities of the photoelectron lines resulting from the absorption of photons from both fields strongly depend both on the respective phases of the fields and on atomic quantities such as the asymmetry parameter. These phases, which are notoriously difficult to measure, can be estimated by changing the polarization state of the laser radiation.

  4. Attenuated phase-shift mask for mitigation of photon shot noise effect in contact hole pattern for extreme ultraviolet lithography

    NASA Astrophysics Data System (ADS)

    Kim, Jung Sik; Hong, Seongchul; Lee, Jae Uk; Lee, Seung Min; Ahn, Jinho

    2014-09-01

    In extreme ultraviolet lithography (EUVL), insufficient light source power is the biggest concern for high-volume manufacturing. Additionally, the photon shot noise (PSN) effect is believed to be the main source of degradation in various aspects of imaging performance. In this study, we propose an attenuated phase-shift mask (PSM) as a solution to both of these issues, yielding improved mask performance for the printing of small contact hole (C/H) patterns. Our PSM shows superior imaging performance over that of a binary intensity mask. We speculate that the stochastic imaging characteristics are improved by the enhanced diffraction efficiency of the PSM.

  5. Spatio-temporal coherence of free-electron laser radiation in the extreme ultraviolet determined by a Michelson interferometer

    NASA Astrophysics Data System (ADS)

    Hilbert, V.; Rödel, C.; Brenner, G.; Döppner, T.; Düsterer, S.; Dziarzhytski, S.; Fletcher, L.; Förster, E.; Glenzer, S. H.; Harmand, M.; Hartley, N. J.; Kazak, L.; Komar, D.; Laarmann, T.; Lee, H. J.; Ma, T.; Nakatsutsumi, M.; Przystawik, A.; Redlin, H.; Skruszewicz, S.; Sperling, P.; Tiggesbäumker, J.; Toleikis, S.; Zastrau, U.

    2014-09-01

    A key feature of extreme ultraviolet (XUV) radiation from free-electron lasers (FELs) is its spatial and temporal coherence. We measured the spatio-temporal coherence properties of monochromatized FEL pulses at 13.5 nm using a Michelson interferometer. A temporal coherence time of (59±8) fs has been determined, which is in good agreement with the spectral bandwidth given by the monochromator. Moreover, the spatial coherence in vertical direction amounts to about 15% of the beam diameter and about 12% in horizontal direction. The feasibility of measuring spatio-temporal coherence properties of XUV FEL radiation using interferometric techniques advances machine operation and experimental studies significantly.

  6. The Laser-assisted photoelectric effect of He, Ne, Ar and Xe in intense extreme ultraviolet and infrared laser fields

    NASA Astrophysics Data System (ADS)

    Hayden, P.; Dardis, J.; Hough, P.; Richardson, V.; Kennedy, E. T.; Costello, J. T.; Düsterer, S.; Redlin, H.; Feldhaus, J.; Li, W. B.; Cubaynes, D.; Meyer, M.

    2016-02-01

    In this paper, we report results on two-colour above-threshold ionisation, where extreme ultraviolet pulses of femtosecond duration were synchronised to intense infrared laser pulses of picosecond duration, in order to study the laser-assisted photoelectric effect of atomic helium, neon, krypton and xenon which leads to the appearance of characteristic sidebands in the photoelectron spectra. The observed trends are found to be well described by a simple model based on the soft-photon approximation, at least for the relatively low optical intensities of up to ? employed in these early experiments.

  7. Spatio-temporal coherence of free-electron laser radiation in the extreme ultraviolet determined by a Michelson interferometer

    SciTech Connect

    Hilbert, V.; Rödel, C.; Zastrau, U.; Brenner, G.; Düsterer, S.; Dziarzhytski, S.; Harmand, M.; Przystawik, A.; Redlin, H.; Toleikis, S.; Döppner, T.; Ma, T.; Fletcher, L.; Förster, E.; Glenzer, S. H.; Lee, H. J.; Hartley, N. J.; Kazak, L.; Komar, D.; Skruszewicz, S.; and others

    2014-09-08

    A key feature of extreme ultraviolet (XUV) radiation from free-electron lasers (FELs) is its spatial and temporal coherence. We measured the spatio-temporal coherence properties of monochromatized FEL pulses at 13.5 nm using a Michelson interferometer. A temporal coherence time of (59±8) fs has been determined, which is in good agreement with the spectral bandwidth given by the monochromator. Moreover, the spatial coherence in vertical direction amounts to about 15% of the beam diameter and about 12% in horizontal direction. The feasibility of measuring spatio-temporal coherence properties of XUV FEL radiation using interferometric techniques advances machine operation and experimental studies significantly.

  8. High-resolution tangential absolute extreme ultraviolet arrays for radiated power density measurements on NSTX-U

    SciTech Connect

    Delgado-Aparicio, L.; Bell, R. E.; Diallo, A.; Gerhardt, S. P.; Kozub, T. A.; LeBlanc, B. P.; Stratton, B. C.; Faust, I.; Tritz, K.

    2014-11-15

    The radiated-power-density diagnostic on the equatorial midplane for the NSTX-U tokamak will be upgraded to measure the radial structure of the photon emissivity profile with an improved radial resolution. This diagnostic will enhance the characterization and studies of power balance, impurity transport, and MHD. The layout and response expected of the new system is shown for different plasma conditions and impurity concentrations. The effect of toroidal rotation driving poloidal asymmetries in the core radiation from high-Z impurities is also addressed.

  9. Uncovering new thermal and mechanical behavior at the nanoscale using coherent extreme ultraviolet light

    NASA Astrophysics Data System (ADS)

    Hoogeboom-Pot, Kathleen Marie

    Tremendous recent progress in nanofabrication capabilities has made high-quality single-atomic layers and nanostructures with dimensions well below 50 nm commonplace, enabling unprecedented access to materials at the nanoscale. However, tools and techniques capable of characterizing the properties and function of nanosystems are still quite limited, leaving much of the fundamental physics that dominates material behavior in the deep nano-regime still unknown. Further understanding gained by studying nanoscale materials is critical both to fundamental science and to continued technological development. This thesis applies coherent extreme ultraviolet (EUV) light from tabletop high harmonic generation to study nanoscale systems on their intrinsic length and time scales (nanometers and femtoseconds, and above), specifically following thermal transport and acoustic dynamics. These studies have shown where and how nanostructured material properties can be quite different from their bulk counterparts. This has in turn allowed us to develop new theoretical descriptions to guide further work. By observing heat dissipation from the smallest nanostructure heat sources measured to date (at 20 nm in lateral size), this work uncovers a previously unobserved and unpredicted nanoscale thermal transport regime where both size and spacing of heat sources play a role in determining the heat dissipation effciency. Surprisingly, this shows that nanoscale heat sources can cool more quickly when spaced close together than when far apart. This discovery is significant to the engineering of thermal management in nanoscale systems and devices while also revealing new insight into the fundamental nature of thermal transport. Furthermore, we harness this new regime to demonstrate the first experimental measurement of the differential contributions of phonons with different mean free paths to thermal conductivity, down to mean free paths as short as 14 nm for the first time. The same

  10. Orbiting Retrievable Far and Extreme Ultraviolet Spectrometer - Shuttle Pallet Satellite (ORFEUS-SPAS)

    NASA Technical Reports Server (NTRS)

    1993-01-01

    The objective of the ORFEUS mission is to launch a deployable/retrievable astronomical platform and obtain ultraviolet spectra for both astrophysically interesting sources and the intervening interstellar medium. Also, the IMAX cameras will obtain footage of both the Shuttle and the ORFEUS-SPAS satellite during the deployment/retrieval operations phase of the ORFEUS-SPAS mission.

  11. On the maximum conversion efficiency into the 13.5-nm extreme ultraviolet emission under a steady-state laser ablation of tin microspheres

    NASA Astrophysics Data System (ADS)

    Basko, M. M.

    2016-08-01

    Theoretical investigation has been performed on the conversion efficiency (CE) into the 13.5-nm extreme ultraviolet (EUV) radiation in a scheme where spherical microspheres of tin (Sn) are simultaneously irradiated by two laser pulses with substantially different wavelengths. The low-intensity short-wavelength pulse is used to control the rate of mass ablation and the size of the EUV source, while the high-intensity long-wavelength pulse provides efficient generation of the EUV light at λ=13.5 nm. The problem of full optimization for maximizing the CE is formulated and solved numerically by performing two-dimensional radiation-hydrodynamics simulations with the RALEF-2D code under the conditions of steady-state laser illumination. It is shown that, within the implemented theoretical model, steady-state CE values approaching 9% are feasible; in a transient peak, the maximum instantaneous CE of 11.5% was calculated for the optimized laser-target configuration. The physical factors, bringing down the fully optimized steady-state CE to about one half of the absolute theoretical maximum of CE≈20 % for the uniform static Sn plasma, are analyzed in detail.

  12. Optical to extreme ultraviolet reddening curves for normal AGN dust and for dust associated with high-velocity outflows

    NASA Astrophysics Data System (ADS)

    Singh, Japneet; Gaskell, Martin; Gill, Jake

    2017-01-01

    We use mid-IR (WIRE), optical (SDSS), and ultraviolet (GALEX) photometry of over 80,000 AGNs to derive mean attenuation curves from the optical to the rest frame extreme ultraviolet (EUV) for (i) “normal” AGN dust dominating the optical reddening of AGNs and (ii) “BAL dust” - the dust causing the additional extinction in AGNs observed to have broad absorption lines (BALs). Our method confirms that the attenuation curve of “normal” AGN dust is flat in the ultraviolet, as found by Gaskell et al. (2004). In striking contrast to this, the attenuation curve for BAL dust is well fit by a steeply-rising, SMC-like curve. We confirm the shape of the theoretical Weingartner & Draine (2001) SMC curve out to 700 Angstroms but the drop in attenuation to still shorter wavelengths (400 Angstroms) seems to be less than predicted. We find identical attenuation curves for high-ionization and low-ionization BALQSOs. We suggest that attenuation curves appearing to be steeper than the SMC are due to differences in underlying spectra and partial covering by BAL dust. This work was This work was performed under the auspices of the Science Internship Program (SIP) of the University of California at Santa Cruz performed under the auspices of the Science Internship Program (SIP) of the University of California at Santa Cruz.

  13. Operation of a free electron laser in the wavelength range from the extreme ultraviolet to the water window

    SciTech Connect

    Ackermann, W.; Asova, G.; Ayvazyan, V.; Azima, A.; Baboi, N.; Bahr, J.; Balandin, V.; Beutner, B.; Brandt, A.; Bolzmann, A.; Brinkmann, R.; /DESY /Dubna, JINR

    2007-01-01

    We report results on the performance of a free-electron laser operating at a wavelength of 13.7 nm where unprecedented peak and average powers for a coherent extreme-ultraviolet radiation source have been measured. In the saturation regime, the peak energy approached 170 J for individual pulses, and the average energy per pulse reached 70 J. The pulse duration was in the region of 10 fs, and peak powers of 10 GW were achieved. At a pulse repetition frequency of 700 pulses per second, the average extreme-ultraviolet power reached 20 mW. The output beam also contained a significant contribution from odd harmonics of approximately 0.6% and 0.03% for the 3rd (4.6 nm) and the 5th (2.75 nm) harmonics, respectively. At 2.75 nm the 5th harmonic of the radiation reaches deep into the water window, a wavelength range that is crucially important for the investigation of biological samples.

  14. Use of Proportional Counters for Yield Measurement in Extremely Short Pulses of Fast Neutrons: Counting Statistics and Absolute Calibration

    NASA Astrophysics Data System (ADS)

    Tarifeño-Saldivia, A.; Mayer, R. E.; Pavez, C.; Soto, L.

    2010-08-01

    A method for absolute calibration of proportional counters for pulsed fast neutrons is presented. The method is based on the use of an isotopic standard source and development of a model for counting detected events from area of a signal compounded by single piled up neutron pulses. Effects of detection counting statistics and electrical background noise are also considered.

  15. Radiation hardness of AlxGa1-xN photodetectors exposed to Extreme UltraViolet (EUV) light beam

    NASA Astrophysics Data System (ADS)

    Malinowski, Pawel E.; John, Joachim; Barkusky, Frank; Duboz, Jean Yves; Lorenz, Anne; Cheng, Kai; Derluyn, Joff; Germain, Marianne; De Moor, Piet; Minoglou, Kyriaki; Bayer, Armin; Mann, Klaus; Hochedez, Jean-Francois; Giordanengo, Boris; Borghs, Gustaaf; Mertens, Robert

    2009-05-01

    We report on the results of fabrication and optoelectrical characterization of Gallium Nitride (GaN) based Extreme UltraViolet (EUV) photodetectors. Our devices were Schottky photodiodes with a finger-shaped rectifying contact, allowing better penetration of light into the active region. GaN layers were epitaxially grown on Silicon (111) by Metal- Organic-Chemical Vapor Deposition (MOCVD). Spectral responsivity measurements in the Near UltraViolet (NUV) wavelength range (200-400 nm) were performed to verify the solar blindness of the photodetectors. After that the devices were exposed to the EUV focused beam of 13.5 nm wavelength using table-top EUV setup. Radiation hardness was tested up to a dose of 3.3Â.1019 photons/cm2. Stability of the quantum efficiency was compared to the one measured in the same way for a commercially available silicon based photodiode. Superior behavior of GaN devices was observed at the wavelength of 13.5 nm.

  16. Method for high-precision multi-layered thin film deposition for deep and extreme ultraviolet mirrors

    DOEpatents

    Ruffner, J.A.

    1999-06-15

    A method for coating (flat or non-flat) optical substrates with high-reflectivity multi-layer coatings for use at Deep Ultra-Violet (DUV) and Extreme Ultra-Violet (EUV) wavelengths. The method results in a product with minimum feature sizes of less than 0.10 [micro]m for the shortest wavelength (13.4 nm). The present invention employs a computer-based modeling and deposition method to enable lateral and vertical thickness control by scanning the position of the substrate with respect to the sputter target during deposition. The thickness profile of the sputter targets is modeled before deposition and then an appropriate scanning algorithm is implemented to produce any desired, radially-symmetric thickness profile. The present invention offers the ability to predict and achieve a wide range of thickness profiles on flat or figured substrates, i.e., account for 1/R[sup 2] factor in a model, and the ability to predict and accommodate changes in deposition rate as a result of plasma geometry, i.e., over figured substrates. 15 figs.

  17. ZnO quantum dot-doped graphene/h-BN/GaN-heterostructure ultraviolet photodetector with extremely high responsivity.

    PubMed

    Lu, Yanghua; Wu, Zhiqian; Xu, Wenli; Lin, Shisheng

    2016-12-02

    A ZnO quantum dot  photo-doped graphene/h-BN/GaN-heterostructure ultraviolet photodetector with extremely high responsivity of more than 1915 A W(-1) and detectivity of more than 1.02 × 10(13) Jones (Jones = cm Hz(1/2) W(-1)) has been demonstrated. The interfaced h-BN layer increases the barrier height at the graphene/GaN heterojunction, which decreases the dark current and improves the on/off current ratio of the device. The photo-doping effect increases the barrier height and carrier concentration at the graphene/h-BN/GaN heterojunction, thus the responsivity is improved from 1473 A W(-1) to 1915 A W(-1) and the detectivity is improved from 5.8 × 10(12) to 1.0 × 10(13) Jones. Moreover, all of the responsivity and detectivity values are the highest values among all the graphene-based ultraviolet photodetectors.

  18. Method for high-precision multi-layered thin film deposition for deep and extreme ultraviolet mirrors

    DOEpatents

    Ruffner, Judith Alison

    1999-01-01

    A method for coating (flat or non-flat) optical substrates with high-reflectivity multi-layer coatings for use at Deep Ultra-Violet ("DUV") and Extreme Ultra-Violet ("EUV") wavelengths. The method results in a product with minimum feature sizes of less than 0.10-.mu.m for the shortest wavelength (13.4-nm). The present invention employs a computer-based modeling and deposition method to enable lateral and vertical thickness control by scanning the position of the substrate with respect to the sputter target during deposition. The thickness profile of the sputter targets is modeled before deposition and then an appropriate scanning algorithm is implemented to produce any desired, radially-symmetric thickness profile. The present invention offers the ability to predict and achieve a wide range of thickness profiles on flat or figured substrates, i.e., account for 1/R.sup.2 factor in a model, and the ability to predict and accommodate changes in deposition rate as a result of plasma geometry, i.e., over figured substrates.

  19. Response of Jupiter's inner magnetosphere to the solar wind derived from extreme ultraviolet monitoring of the Io plasma torus

    NASA Astrophysics Data System (ADS)

    Murakami, Go; Yoshioka, Kazuo; Yamazaki, Atsushi; Tsuchiya, Fuminori; Kimura, Tomoki; Tao, Chihiro; Kita, Hajime; Kagitani, Masato; Sakanoi, Takeshi; Uemizu, Kazunori; Kasaba, Yasumasa; Yoshikawa, Ichiro; Fujimoto, Masaki

    2016-12-01

    Because Jupiter's magnetosphere is huge and is rotationally dominated, solar wind influence on its inner part has been thought to be negligible. Meanwhile, dawn-dusk asymmetric features of this region have been reported. Presence of dawn-to-dusk electric field is one of the leading explanations of the asymmetry; however, the physical process of generating such an intense electric field still remains unclear. Here we present long and continuous monitoring of the extreme ultraviolet emissions from the Io plasma torus in Jupiter's inner magnetosphere made by the Hisaki satellite between December 2013 and March 2014. We found five occasions where the dusk/dawn brightness ratio was enhanced above 2.5 in response to rapid increase of the solar wind dynamic pressure. The enhancement is achieved as the dusk region brightens and the dawn region dims. The observation indicates that dawn-to-dusk electric field in the inner magnetosphere is enhanced under compressed conditions.

  20. Effects of the dynamics of droplet-based laser-produced plasma on angular extreme ultraviolet emission profile

    SciTech Connect

    Giovannini, Andrea Z.; Abhari, Reza S.

    2014-05-12

    The emission distribution of extreme ultraviolet (EUV) radiation from droplet targets is dependent on the dynamics of the laser-produced plasma. The EUV emission is measured on a 2% bandwidth centered at 13.5 nm (in-band). The targets of the laser are small (sub-50 μm) tin droplets, and the in-band emission distribution is measured for different laser irradiances and droplet sizes at various angular positions. Larger droplets lead to a faster decay of EUV emission at larger angles with respect to the laser axis. A decrease in laser irradiance has the opposite effect. The measurements are used together with an analytical model to estimate plume dynamics. Additionally, the model is used to estimate EUV emission distribution for a desired droplet diameter and laser irradiance.

  1. Extended-range grazing-incidence spectrometer for high-resolution extreme ultraviolet measurements on an electron beam ion trap

    SciTech Connect

    Beiersdorfer, P.; Magee, E. W.; Brown, G. V.; Träbert, E.; Widmann, K.; Hell, N.

    2014-11-15

    A high-resolution grazing-incidence grating spectrometer has been implemented on the Livermore electron beam ion traps for performing very high-resolution measurements in the soft x-ray and extreme ultraviolet region spanning from below 10 Å to above 300 Å. The instrument operates without an entrance slit and focuses the light emitted by highly charged ions located in the roughly 50 μm wide electron beam onto a cryogenically cooled back-illuminated charge-coupled device detector. The measured line widths are below 0.025 Å above 100 Å, and the resolving power appears to be limited by the source size and Doppler broadening of the trapped ions. Comparisons with spectra obtained with existing grating spectrometers show an order of magnitude improvement in spectral resolution.

  2. Solar extreme ultraviolet (EUV) flare observations and findings from the Solar Dynamics Observatory (SDO) EUV Variability Experiment (EVE)

    NASA Astrophysics Data System (ADS)

    Woods, Thomas N.; Eparvier, Francis G.; Mason, James P.

    New solar soft X-ray (SXR) and extreme ultraviolet (EUV) irradiance observations from NASA Solar Dynamics Observatory (SDO) EUV Variability Experiment (EVE) provide full coverage from 0.1 to 106 nm and continuously at a cadence of 10 seconds for spectra at 0.1 nm resolution. These observations during flares can usually be decomposed into four distinct characteristics: impulsive phase, gradual phase, coronal dimming, and EUV late phase. Over 6000 flares have been observed during the SDO mission; some flares show all four phases, and some only show the gradual phase. The focus is on the newer results about the EUV late phase and coronal dimming and its relationship to coronal mass ejections (CMEs). These EVE flare measurements are based on observing the sun-as-a-star, so these results could exemplify stellar flares. Of particular interest is that new coronal dimming measurements of stars could be used to estimate mass and velocity of stellar CMEs.

  3. Ultrafast Spin Crossover in [Fe(II) (bpy)3 ](2+) : Revealing Two Competing Mechanisms by Extreme Ultraviolet Photoemission Spectroscopy.

    PubMed

    Moguilevski, Alexandre; Wilke, Martin; Grell, Gilbert; Bokarev, Sergey I; Aziz, Saadullah G; Engel, Nicholas; Raheem, Azhr A; Kühn, Oliver; Kiyan, Igor Yu; Aziz, Emad F

    2016-12-22

    Photoinduced spin-flip in Fe(II) complexes is an ultrafast phenomenon that has the potential to become an alternative to conventional processing and magnetic storage of information. Following the initial excitation by visible light into the singlet metal-to-ligand charge-transfer state, the electronic transition to the high-spin quintet state may undergo different pathways. Here we apply ultrafast XUV (extreme ultraviolet) photoemission spectroscopy to track the low-to-high spin dynamics in the aqueous iron tris-bipyridine complex, [Fe(bpy)3 ](2+) , by monitoring the transient electron density distribution among excited states with femtosecond time resolution. Aided by first-principles calculations, this approach enables us to reveal unambiguously both the sequential and direct de-excitation pathways from singlet to quintet state, with a branching ratio of 4.5:1.

  4. Extended-range grazing-incidence spectrometer for high-resolution extreme ultraviolet measurements on an electron beam ion trap.

    PubMed

    Beiersdorfer, P; Magee, E W; Brown, G V; Hell, N; Träbert, E; Widmann, K

    2014-11-01

    A high-resolution grazing-incidence grating spectrometer has been implemented on the Livermore electron beam ion traps for performing very high-resolution measurements in the soft x-ray and extreme ultraviolet region spanning from below 10 Å to above 300 Å. The instrument operates without an entrance slit and focuses the light emitted by highly charged ions located in the roughly 50 μm wide electron beam onto a cryogenically cooled back-illuminated charge-coupled device detector. The measured line widths are below 0.025 Å above 100 Å, and the resolving power appears to be limited by the source size and Doppler broadening of the trapped ions. Comparisons with spectra obtained with existing grating spectrometers show an order of magnitude improvement in spectral resolution.

  5. Optimization of the size ratio of Sn sphere and laser focal spot for an extreme ultraviolet light source

    SciTech Connect

    Yuspeh, S.; Sequoia, K. L.; Tao, Y.; Tillack, M. S.; Burdt, R.; Najmabadi, F.

    2008-12-01

    The effect of the ratio of Sn sphere diameter to laser focal spot size (SD/FSS) on conversion efficiency (CE) from laser to in-band (2%) 13.5 nm extreme ultraviolet (EUV) light was investigated by fixing the laser spot size and irradiating variable diameter spheres. It was found that a minimum SD/FSS, i.e., 2.5, is necessary to produce high in-band CE, which is 15% higher than planar targets. Two-dimensional plasma density profile maps showed that the density of the dominant in-band EUV emission region and the size of the surrounding absorbing plasma can be manipulated by geometric effects of the SD/FSS ratio.

  6. A solar type II radio burst from coronal mass ejection-coronal ray interaction: Simultaneous radio and extreme ultraviolet imaging

    SciTech Connect

    Chen, Yao; Du, Guohui; Feng, Shiwei; Kong, Xiangliang; Wang, Bing; Feng, Li; Guo, Fan; Li, Gang

    2014-05-20

    Simultaneous radio and extreme ultraviolet (EUV)/white-light imaging data are examined for a solar type II radio burst occurring on 2010 March 18 to deduce its source location. Using a bow-shock model, we reconstruct the three-dimensional EUV wave front (presumably the type-II-emitting shock) based on the imaging data of the two Solar TErrestrial RElations Observatory spacecraft. It is then combined with the Nançay radio imaging data to infer the three-dimensional position of the type II source. It is found that the type II source coincides with the interface between the coronal mass ejection (CME) EUV wave front and a nearby coronal ray structure, providing evidence that the type II emission is physically related to the CME-ray interaction. This result, consistent with those of previous studies, is based on simultaneous radio and EUV imaging data for the first time.

  7. Efficient extreme ultraviolet plasma source generated by a CO{sub 2} laser and a liquid xenon microjet target

    SciTech Connect

    Ueno, Yoshifumi; Ariga, Tatsuya; Soumagne, George; Higashiguchi, Takeshi; Kubodera, Shoichi; Pogorelsky, Igor; Pavlishin, Igor; Stolyarov, Daniil; Babzien, Marcus; Kusche, Karl; Yakimenko, Vitaly

    2007-05-07

    We demonstrated efficacy of a CO{sub 2}-laser-produced xenon plasma in the extreme ultraviolet (EUV) spectral region at 13.5 nm at variable laser pulse widths between 200 ps and 25 ns. The plasma target was a 30 {mu}m liquid xenon microjet. To ensure the optimum coupling of CO{sub 2} laser energy with the plasma, they applied a prepulse yttrium aluminum garnet laser. The authors measured the conversion efficiency (CE) of the 13.5 nm EUV emission for different pulse widths of the CO{sub 2} laser. A maximum CE of 0.6% was obtained for a CO{sub 2} laser pulse width of 25 ns at an intensity of 5x10{sup 10} W/cm{sup 2}.

  8. Influence of electrode separation and gas curtain on extreme ultraviolet emission of a gas jet z-pinch source

    NASA Astrophysics Data System (ADS)

    Mohanty, S. R.; Sakamoto, T.; Kobayashi, Y.; Izuka, N.; Kishi, N.; Song, I.; Watanabe, M.; Kawamura, T.; Okino, A.; Horioka, K.; Hotta, E.

    2006-07-01

    Extreme ultraviolet (EUV) emission from a gas jet z-pinch source has been examined by employing a photodiode and pinhole camera. Visible images of the pinched plasma have been also recorded. A current pulse of 10kA is used to heat the gas jet, which emits radiation around 13.5nm. Experimental parameters such as electrode separation and gas flow rate are varied to optimize EUV emission. The maximum EUV energy is obtained for 12mm electrode separation and 20Torr xenon pressure and it is estimated to 10.95mJ/sr per 2% bandwidth per pulse. The presence of gas curtain improves EUV emission by 30%.

  9. Extended-range grazing-incidence spectrometer for high-resolution extreme ultraviolet measurements on an electron beam ion trapa)

    NASA Astrophysics Data System (ADS)

    Beiersdorfer, P.; Magee, E. W.; Brown, G. V.; Hell, N.; Träbert, E.; Widmann, K.

    2014-11-01

    A high-resolution grazing-incidence grating spectrometer has been implemented on the Livermore electron beam ion traps for performing very high-resolution measurements in the soft x-ray and extreme ultraviolet region spanning from below 10 Å to above 300 Å. The instrument operates without an entrance slit and focuses the light emitted by highly charged ions located in the roughly 50 μm wide electron beam onto a cryogenically cooled back-illuminated charge-coupled device detector. The measured line widths are below 0.025 Å above 100 Å, and the resolving power appears to be limited by the source size and Doppler broadening of the trapped ions. Comparisons with spectra obtained with existing grating spectrometers show an order of magnitude improvement in spectral resolution.

  10. Correlation method for the measure of mask-induced line-edge roughness in extreme ultraviolet lithography

    SciTech Connect

    Naulleau, Patrick

    2009-05-25

    As critical dimensions for leading-edge semiconductor devices shrink, line-edge roughness (LER) requirements are pushing well into the single digit nanometer regime. At these scales many new sources of LER must be considered. In the case of extreme ultraviolet (EUV) lithography, modeling has shown the lithographic mask to be a source of significant concern. Here we present a correlation-based methodology for experimentally measuring the magnitude of mask contributors to printed LER. The method is applied to recent printing results from a 0.3 numerical aperture EUV microfield exposure tool. The measurements demonstrate that such effects are indeed present and of significant magnitude. The method is also used to explore the effects of illumination coherence and defocus and has been used to verify model-based predictions of mask-induced LER.

  11. The Extreme Ultraviolet Spectrograph Sounding Rocket Payload: Recent Modifications for Planetary Observations in the EUV/FUV

    NASA Technical Reports Server (NTRS)

    Slater, David C.; Stern, S. Alan; Scherrer, John; Cash, Webster; Green, James C.; Wilkinson, Erik

    1995-01-01

    We report on the status of modifications to an existing extreme ultraviolet (EUV) telescope/spectrograph sounding rocket payload for planetary observations in the 800 - 1200 A wavelength band. The instrument is composed of an existing Wolter Type 2 grazing incidence telescope, a newly built 0.4-m normal incidence Rowland Circle spectrograph, and an open-structure resistive-anode microchannel plate detector. The modified payload has successfully completed three NASA sounding rocket flights within 1994-1995. Future flights are anticipated for additional studies of planetary and cometary atmospheres and interstellar absorption. A detailed description of the payload, along with the performance characteristics of the integrated instrument are presented. In addition, some preliminary flight results from the above three missions are also presented.

  12. The Solar Chromosphere/Corona Interface. I. Far-Ultraviolet to Extreme-Ultraviolet Observations and Modeling of Unresolved Coronal Funnels

    NASA Technical Reports Server (NTRS)

    Martinez-Galarce, Dennis S.; Walker, Arthur C., III; Barbee, Troy W., II; Hoover, Richard B.

    2003-01-01

    A coronal funnel model, developed by D. Rabin, was tested against a calibrated spectroheliogram recorded in the 170-1 75 A bandpass. This image was recorded on board a sounding-rocket experiment flown on 1994 November 3, called the Multi-Spectral Solar Telescope Array II (MSSTA II). MSSTA, a joint project of Stanford University, the NASA Marshall Space Flight Center, and the Lawrence Livermore National Laboratory' is an observing platform composed of a set of normal-incidence, multilayer-coated optics designed to obtain narrow-bandpass, high-resolution images (1 sec.- 3 sec.) at selected far-ultraviolet (FUV), extreme-ultraviolet (EUV), and soft X-ray wavelengths (44-1550 A). Using full disk images centered at 1550 A (C IV) and 173 A (Fe IX/X), the funnel model, which is based on coronal back-heating, was tested against the data incorporating observed constraints on global coverage and measured flux. Found was a class of funnel models that could account for the quiescent, globally diffuse and unresolved emission seen in the 171-175 A bandpass, where the funnels are assumed to be rooted in the C IV supergranular network. These models, when incorporated with the CHIANTI spectral code, suggest that this emission is mostly of upper transition region origin and primarily composed of Fe IX plasma. The funnels are found to have constrictions, Gamma approx. 6-20, which is in good agreement with the observations. Further, the fitted models simultaneously satisfy global areal constraints seen in both images; namely,that a global network of funnels must cover approx. 700 - 95% of the total solar surface area seen in the 171-175 A image, and a 5% of the disk area seen in the 1550 A bandpass. These findings support the configuration of the EUV magnetic network as suggested by Reeves et al. and put forth in more detail by Gabriel. Furthermore, the models are in good agreement with differential emission measure estimates made of the transition region by J. C. Raymond & J. G

  13. FIBRILLAR CHROMOSPHERIC SPICULE-LIKE COUNTERPARTS TO AN EXTREME-ULTRAVIOLET AND SOFT X-RAY BLOWOUT CORONAL JET

    SciTech Connect

    Sterling, Alphonse C.; Moore, Ronald L.; Harra, Louise K. E-mail: ron.moore@nasa.go

    2010-10-20

    We observe an erupting jet feature in a solar polar coronal hole, using data from Hinode/Solar Optical Telescope (SOT), Extreme Ultraviolet Imaging Spectrometer (EIS), and X-Ray Telescope (XRT), with supplemental data from STEREO/EUVI. From extreme-ultraviolet (EUV) and soft X-ray (SXR) images we identify the erupting feature as a blowout coronal jet: in SXRs it is a jet with a bright base, and in EUV it appears as an eruption of relatively cool ({approx}50,000 K) material of horizontal size scale {approx}30'' originating from the base of the SXR jet. In SOT Ca II H images, the most pronounced analog is a pair of thin ({approx}1'') ejections at the locations of either of the two legs of the erupting EUV jet. These Ca II features eventually rise beyond 45'', leaving the SOT field of view, and have an appearance similar to standard spicules except that they are much taller. They have velocities similar to that of 'type II' spicules, {approx}100 km s{sup -1}, and they appear to have spicule-like substructures splitting off from them with horizontal velocity {approx}50 km s{sup -1}, similar to the velocities of splitting spicules measured by Sterling et al. Motions of splitting features and of other substructures suggest that the macroscopic EUV jet is spinning or unwinding as it is ejected. This and earlier work suggest that a subpopulation of Ca II type II spicules are the Ca II manifestation of portions of larger scale erupting magnetic jets. A different subpopulation of type II spicules could be blowout jets occurring on a much smaller horizontal size scale than the event we observe here.

  14. High-space resolution imaging plate analysis of extreme ultraviolet (EUV) light from tin laser-produced plasmas

    NASA Astrophysics Data System (ADS)

    Musgrave, Christopher S. A.; Murakami, Takehiro; Ugomori, Teruyuki; Yoshida, Kensuke; Fujioka, Shinsuke; Nishimura, Hiroaki; Atarashi, Hironori; Iyoda, Tomokazu; Nagai, Keiji

    2017-03-01

    With the advent of high volume manufacturing capabilities by extreme ultraviolet lithography, constant improvements in light source design and cost-efficiency are required. Currently, light intensity and conversion efficiency (CE) measurments are obtained by charged couple devices, faraday cups etc, but also phoshpor imaging plates (IPs) (BaFBr:Eu). IPs are sensitive to light and high-energy species, which is ideal for studying extreme ultraviolet (EUV) light from laser produced plasmas (LPPs). In this work, we used IPs to observe a large angular distribution (10°-90°). We ablated a tin target by high-energy lasers (1064 nm Nd:YAG, 1010 and 1011 W/cm2) to generate the EUV light. The europium ions in the IP were trapped in a higher energy state from exposure to EUV light and high-energy species. The light intensity was angular dependent; therefore excitation of the IP depends on the angle, and so highly informative about the LPP. We obtained high-space resolution (345 μm, 0.2°) angular distribution and grazing spectrometer (5-20 nm grate) data simultaneously at different target to IP distances (103 mm and 200 mm). Two laser systems and IP types (BAS-TR and BAS-SR) were also compared. The cosine fitting values from the IP data were used to calculate the CE to be 1.6% (SD ± 0.2) at 13.5 nm 2% bandwidth. Finally, a practical assessment of IPs and a damage issue are disclosed.

  15. EFFECTS OF ULTRAVIOLET RADIATION ON THE MODERATE HALOPHILE HALOMONAS ELONGATA AND THE EXTREME HALOPHILE HALOBACTERIUM SALINARUM

    EPA Science Inventory

    Both the moderately halophilic bacterium, Halomonas elongata, and the extremely halophilic archaea, Halobacterium salinarum, can be found in hypersaline environments (e.g., salterns). On complex media, H. elongata grows over a salt range of 0.05-5.2 M, whereas, H. salinarum multi...

  16. Extreme ultraviolet performance of a multilayer coated high density toroidal grating

    NASA Technical Reports Server (NTRS)

    Thomas, Roger J.; Keski-Kuha, Ritva A. M.; Neupert, Werner M.; Condor, Charles E.; Gum, Jeffrey S.

    1991-01-01

    The performance of a multilayer coated diffraction grating has been evaluated at EUV wavelengths both in terms of absolute efficiency and spectral resolution. The application of ten-layer Ir/Si multilayer coating to a 3600-lines/mm blazed toroidal replica grating produced a factor of 9 enhancement in peak efficiency near the design wavelength of about 30 nm in first order, without degrading its excellent quasistigmatic spectral resolution. The measured EUV efficiency peaked at 3.3 percent and was improved over the full spectral range between 25 and 35 nm compared with the premultilayer replica which had a standard gold coating. In addition, the grating's spectral resolution of greater than 5000 was maintained.

  17. Fragmentation Pathways of H+(H2O)2 after Extreme Ultraviolet Photoionization

    NASA Astrophysics Data System (ADS)

    Lammich, L.; Domesle, C.; Jordon-Thaden, B.; Förstel, M.; Arion, T.; Lischke, T.; Heber, O.; Klumpp, S.; Martins, M.; Guerassimova, N.; Treusch, R.; Ullrich, J.; Hergenhahn, U.; Pedersen, H. B.; Wolf, A.

    2010-12-01

    Photofragmentation of the protonated water dimer H+(H2O)2, a fundamental system both in aqueous solutions and gas-phase water clusters, has been studied at 13.8 nm using the Free Electron Laser FLASH in Hamburg. In a crossed-beam experiment using time-resolved, single-molecule fragment imaging, the two-body breakup into H2O++H3O+ was found as a prominent fragmentation channel with a kinetic energy release of up to 10 eV. This channel was observed with at least a similar yield as events with stronger fragmentation, producing protons together with neutral fragments and showing an absolute cross section of (0.5±0.2)×10-18cm2.

  18. Fragmentation pathways of H+(H2O)2 after extreme ultraviolet photoionization.

    PubMed

    Lammich, L; Domesle, C; Jordon-Thaden, B; Förstel, M; Arion, T; Lischke, T; Heber, O; Klumpp, S; Martins, M; Guerassimova, N; Treusch, R; Ullrich, J; Hergenhahn, U; Pedersen, H B; Wolf, A

    2010-12-17

    Photofragmentation of the protonated water dimer H+(H2O)_{2}, a fundamental system both in aqueous solutions and gas-phase water clusters, has been studied at 13.8 nm using the Free Electron Laser FLASH in Hamburg. In a crossed-beam experiment using time-resolved, single-molecule fragment imaging, the two-body breakup into H2O++H3O+ was found as a prominent fragmentation channel with a kinetic energy release of up to 10 eV. This channel was observed with at least a similar yield as events with stronger fragmentation, producing protons together with neutral fragments and showing an absolute cross section of (0.5 ± 0.2) × 10(-18) cm2.

  19. Two-colour pump–probe experiments with a twin-pulse-seed extreme ultraviolet free-electron laser

    PubMed Central

    Allaria, E.; Bencivenga, F.; Borghes, R.; Capotondi, F.; Castronovo, D.; Charalambous, P.; Cinquegrana, P.; Danailov, M. B.; De Ninno, G.; Demidovich, A.; Di Mitri, S.; Diviacco, B.; Fausti, D.; Fawley, W. M.; Ferrari, E.; Froehlich, L.; Gauthier, D.; Gessini, A.; Giannessi, L.; Ivanov, R.; Kiskinova, M.; Kurdi, G.; Mahieu, B.; Mahne, N.; Nikolov, I.; Masciovecchio, C.; Pedersoli, E.; Penco, G.; Raimondi, L.; Serpico, C.; Sigalotti, P.; Spampinati, S.; Spezzani, C.; Svetina, C.; Trovò, M.; Zangrando, M.

    2013-01-01

    Exploring the dynamics of matter driven to extreme non-equilibrium states by an intense ultrashort X-ray pulse is becoming reality, thanks to the advent of free-electron laser technology that allows development of different schemes for probing the response at variable time delay with a second pulse. Here we report the generation of two-colour extreme ultraviolet pulses of controlled wavelengths, intensity and timing by seeding of high-gain harmonic generation free-electron laser with multiple independent laser pulses. The potential of this new scheme is demonstrated by the time evolution of a titanium-grating diffraction pattern, tuning the two coherent pulses to the titanium M-resonance and varying their intensities. This reveals that an intense pulse induces abrupt pattern changes on a time scale shorter than hydrodynamic expansion and ablation. This result exemplifies the essential capabilities of the jitter-free multiple-colour free-electron laser pulse sequences to study evolving states of matter with element sensitivity. PMID:24048228

  20. Semiconductor-based superlens for subwavelength resolution below the diffraction limit at extreme ultraviolet frequencies

    NASA Astrophysics Data System (ADS)

    Vincenti, M. A.; D'Orazio, A.; Cappeddu, M. G.; Akozbek, Neset; Bloemer, M. J.; Scalora, M.

    2009-05-01

    We theoretically demonstrate negative refraction and subwavelength resolution below the diffraction limit in the UV and extreme UV ranges using semiconductors. The metal-like response of typical semiconductors such as GaAs or GaP makes it possible to achieve negative refraction and superguiding in resonant semiconductor/dielectric multilayer stacks, similar to what has been demonstrated in metallodielectric photonic band gap structures. The exploitation of this basic property in semiconductors raises the possibility of yet-untapped applications in the UV and soft x-ray ranges.

  1. An extreme ultraviolet Michelson interferometer for experiments at free-electron lasers

    NASA Astrophysics Data System (ADS)

    Hilbert, Vinzenz; Blinne, Alexander; Fuchs, Silvio; Feigl, Torsten; Kämpfer, Tino; Rödel, Christian; Uschmann, Ingo; Wünsche, Martin; Paulus, Gerhard G.; Förster, Eckhart; Zastrau, Ulf

    2013-09-01

    We present a Michelson interferometer for 13.5 nm soft x-ray radiation. It is characterized in a proof-of-principle experiment using synchrotron radiation, where the temporal coherence is measured to be 13 fs. The curvature of the thin-film beam splitter membrane is derived from the observed fringe pattern. The applicability of this Michelson interferometer at intense free-electron lasers is investigated, particularly with respect to radiation damage. This study highlights the potential role of such Michelson interferometers in solid density plasma investigations using, for instance, extreme soft x-ray free-electron lasers. A setup using the Michelson interferometer for pseudo-Nomarski-interferometry is proposed.

  2. Cluster beam targets for laser plasma extreme ultraviolet and soft x-ray sources

    DOEpatents

    Kublak, Glenn D.; Richardson, Martin C. (CREOL

    1996-01-01

    Method and apparatus for producing extreme ultra violet (EUV) and soft x-ray radiation from an ultra-low debris plasma source are disclosed. Targets are produced by the free jet expansion of various gases through a temperature controlled nozzle to form molecular clusters. These target clusters are subsequently irradiated with commercially available lasers of moderate intensity (10.sup.11 -10.sup.12 watts/cm.sup.2) to produce a plasma radiating in the region of 0.5 to 100 nanometers. By appropriate adjustment of the experimental conditions the laser focus can be moved 10-30 mm from the nozzle thereby eliminating debris produced by plasma erosion of the nozzle.

  3. Optical Identification of Quasar 0917+7122 in the Direction of an Extreme-Ultraviolet Source

    NASA Technical Reports Server (NTRS)

    Maoz, D.; Ofek, E. O.; Shemi, A.; Barth, A. J.; Filippenko, A. V.; Brotherton, M. S.; Wills, B. J.; Lockman, F. J.

    1996-01-01

    We report the optical identification of an R = 18.3 mag, z = 2.432 quasar at the position of a 6 cm radio source and a faint ROSAT PSPC X-ray source. The quasar lies within the error circles of unidentified extreme-UV (EUV) detections by the EUVE and ROSAT WFC all-sky surveys at approximately 400 A and approximately 150 A, respectively. A 21 cm H I emission measurement in the direction of the quasar with a 21'-diameter beam yields a total H I column density of N(sub H) = 3.3 x 10(exp 20) /sq cm, two orders of magnitude higher than the maximum allowed for transparency through the Galaxy in the EUV The source of the EUV flux is therefore probably nearby (approximately < 100 pc), and unrelated to the quasar.

  4. An extreme ultraviolet Michelson interferometer for experiments at free-electron lasers.

    PubMed

    Hilbert, Vinzenz; Blinne, Alexander; Fuchs, Silvio; Feigl, Torsten; Kämpfer, Tino; Rödel, Christian; Uschmann, Ingo; Wünsche, Martin; Paulus, Gerhard G; Förster, Eckhart; Zastrau, Ulf

    2013-09-01

    We present a Michelson interferometer for 13.5 nm soft x-ray radiation. It is characterized in a proof-of-principle experiment using synchrotron radiation, where the temporal coherence is measured to be 13 fs. The curvature of the thin-film beam splitter membrane is derived from the observed fringe pattern. The applicability of this Michelson interferometer at intense free-electron lasers is investigated, particularly with respect to radiation damage. This study highlights the potential role of such Michelson interferometers in solid density plasma investigations using, for instance, extreme soft x-ray free-electron lasers. A setup using the Michelson interferometer for pseudo-Nomarski-interferometry is proposed.

  5. An extreme ultraviolet Michelson interferometer for experiments at free-electron lasers

    SciTech Connect

    Hilbert, Vinzenz; Fuchs, Silvio; Paulus, Gerhard G.; Zastrau, Ulf; Blinne, Alexander; Feigl, Torsten; Kämpfer, Tino; Rödel, Christian; Uschmann, Ingo; Wünsche, Martin; Förster, Eckhart

    2013-09-15

    We present a Michelson interferometer for 13.5 nm soft x-ray radiation. It is characterized in a proof-of-principle experiment using synchrotron radiation, where the temporal coherence is measured to be 13 fs. The curvature of the thin-film beam splitter membrane is derived from the observed fringe pattern. The applicability of this Michelson interferometer at intense free-electron lasers is investigated, particularly with respect to radiation damage. This study highlights the potential role of such Michelson interferometers in solid density plasma investigations using, for instance, extreme soft x-ray free-electron lasers. A setup using the Michelson interferometer for pseudo-Nomarski-interferometry is proposed.

  6. Chandra, Extreme Ultraviolet Explorer, and Very Large Array Observations of the Active Binary System σ2 Coronae Borealis

    NASA Astrophysics Data System (ADS)

    Osten, Rachel A.; Ayres, Thomas R.; Brown, Alexander; Linsky, Jeffrey L.; Krishnamurthi, Anita

    2003-01-01

    We present the results of a coordinated observing campaign on the short-period RS CVn binary σ2 Coronae Borealis (F6V+G0V Porb=1.14 days) with the Very Large Array, the Extreme Ultraviolet Explorer, and the Chandra X-Ray Observatory High-Energy Transmission Grating Spectrometer. The radio emission is consistent with previously determined quiescent gyrosynchrotron properties. Multiple flares were seen with Extreme Ultraviolet Explorer, five occurring within two consecutive orbital periods. The first of these flares was observed with Chandra. The Chandra observations of σ2 CrB showed no systematic variations of line fluxes, widths, or Doppler shifts with orbital phase, nor any response in line width or offset due to the flare. This is consistent with both stars being equally active coronal emitters. We have developed a self-consistent method of spectral analysis to derive information from the line and continuum emissions concerning the distribution of plasma with temperature and elemental abundances. A bimodal temperature distribution is appropriate for both quiescent and flare intervals, with a stable peak at 6-8 MK and another variable enhancement at higher temperatures, with evidence for significant contribution from temperatures up to 50 MK during the flare, compared to 30 MK during quiescence. The iron abundance is subsolar during quiescence but is enriched by about a factor of 2 during a large flare seen with Chandra. The noble gas elements neon and argon show elevated abundances with respect to iron, but there is no clear evidence for any first ionization potential-based abundance pattern during quiescence or the flare. We have determined coronal electron densities from the helium-like ions O VII, Ne IX, Mg XI, and Si XIII, which imply densities >=1010 cm-3. There is a small enhancement in the electron densities derived for the flare, but it is not statistically significant. We call attention to electron temperature constraints provided by the ratios of 1s2

  7. Sensitivity-Limiting Factors of at-Wavelength Extreme Ultraviolet Lithography Mask Blank Inspection

    NASA Astrophysics Data System (ADS)

    Tezuka, Yoshihiro; Tanaka, Toshihiko; Terasawa, Tsuneo; Tomie, Toshihisa

    2006-06-01

    Sensitivity-limiting factors of at-wavelength inspection for extreme UV lithography (EUVL) mask blanks have been analyzed. The sensitivity of the inspection tool is modeled on the basis of the inspection image of programmed multilayer defects and the characterized attributes of the tool components. The characterization includes point spread function (PSF) analysis of the imaging optics and the back-illuminated charge-coupled-device (BI-CCD) sensor as well as power spectral density (PSD) analysis of the mask blank surface. The statistical scaling of signal-to-noise ratio (SNR) in conjunction with the variables of optics, sensors, and mask blanks has predicted effective improvement paths of its sensitivity. Increasing the magnification of optics, reducing the total PSF, and improving the roughness of mask blanks will address the needs for its application in future generations. Signal intensity dependency on the geometrical attributes of defects is also studied by both experiment and electromagnetic simulation. It is revealed that the bottom height of defects and defect smoothing throughout the multilayer deposition significantly influence defect signal intensity. Comprehensive measures to accommodate a variety of defects and to mitigate associated risks are also discussed.

  8. Investigating the Effects of Simulated Martian Ultraviolet Radiation on Halococcus dombrowskii and Other Extremely Halophilic Archaebacteria

    PubMed Central

    Fendrihan, Sergiu; Bérces, Attila; Lammer, Helmut; Musso, Maurizio; Rontó, György; Polacsek, Tatjana K.; Holzinger, Anita; Kolb, Christoph; Stan-Lotter, Helga

    2011-01-01

    The isolation of viable extremely halophilic archaea from 250-million-year-old rock salt suggests the possibility of their long-term survival under desiccation. Since halite has been found on Mars and in meteorites, haloarchaeal survival of martian surface conditions is being explored. Halococcus dombrowskii H4 DSM 14522T was exposed to UV doses over a wavelength range of 200–400 nm to simulate martian UV flux. Cells embedded in a thin layer of laboratory-grown halite were found to accumulate preferentially within fluid inclusions. Survival was assessed by staining with the LIVE/DEAD kit dyes, determining colony-forming units, and using growth tests. Halite-embedded cells showed no loss of viability after exposure to about 21 kJ/m2, and they resumed growth in liquid medium with lag phases of 12 days or more after exposure up to 148 kJ/m2. The estimated D37 (dose of 37 % survival) for Hcc. dombrowskii was ≥ 400 kJ/m2. However, exposure of cells to UV flux while in liquid culture reduced D37 by 2 orders of magnitude (to about 1 kJ/m2); similar results were obtained with Halobacterium salinarum NRC-1 and Haloarcula japonica. The absorption of incoming light of shorter wavelength by color centers resulting from defects in the halite crystal structure likely contributed to these results. Under natural conditions, haloarchaeal cells become embedded in salt upon evaporation; therefore, dispersal of potential microscopic life within small crystals, perhaps in dust, on the surface of Mars could resist damage by UV radiation. PMID:19215203

  9. Investigating the effects of simulated martian ultraviolet radiation on Halococcus dombrowskii and other extremely halophilic archaebacteria.

    PubMed

    Fendrihan, Sergiu; Bérces, Attila; Lammer, Helmut; Musso, Maurizio; Rontó, György; Polacsek, Tatjana K; Holzinger, Anita; Kolb, Christoph; Stan-Lotter, Helga

    2009-01-01

    The isolation of viable extremely halophilic archaea from 250-million-year-old rock salt suggests the possibility of their long-term survival under desiccation. Since halite has been found on Mars and in meteorites, haloarchaeal survival of martian surface conditions is being explored. Halococcus dombrowskii H4 DSM 14522(T) was exposed to UV doses over a wavelength range of 200-400 nm to simulate martian UV flux. Cells embedded in a thin layer of laboratory-grown halite were found to accumulate preferentially within fluid inclusions. Survival was assessed by staining with the LIVE/DEAD kit dyes, determining colony-forming units, and using growth tests. Halite-embedded cells showed no loss of viability after exposure to about 21 kJ/m(2), and they resumed growth in liquid medium with lag phases of 12 days or more after exposure up to 148 kJ/m(2). The estimated D(37) (dose of 37 % survival) for Hcc. dombrowskii was > or = 400 kJ/m(2). However, exposure of cells to UV flux while in liquid culture reduced D(37) by 2 orders of magnitude (to about 1 kJ/m(2)); similar results were obtained with Halobacterium salinarum NRC-1 and Haloarcula japonica. The absorption of incoming light of shorter wavelength by color centers resulting from defects in the halite crystal structure likely contributed to these results. Under natural conditions, haloarchaeal cells become embedded in salt upon evaporation; therefore, dispersal of potential microscopic life within small crystals, perhaps in dust, on the surface of Mars could resist damage by UV radiation.

  10. HELIOS—A laboratory based on high-order harmonic generation of extreme ultraviolet photons for time-resolved spectroscopy

    SciTech Connect

    Plogmaker, S. E-mail: Joachim.Terschluesen@physics.uu.se Terschlüsen, J. A. E-mail: Joachim.Terschluesen@physics.uu.se Krebs, N.; Svanqvist, M.; Forsberg, J.; Cappel, U. B.; Rubensson, J.-E.; Siegbahn, H.; Söderström, J. E-mail: Joachim.Terschluesen@physics.uu.se

    2015-12-15

    In this paper, we present the HELIOS (High Energy Laser Induced Overtone Source) laboratory, an in-house high-order harmonic generation facility which generates extreme ultraviolet (XUV) photon pulses in the range of 15-70 eV with monochromatized XUV pulse lengths below 35 fs. HELIOS is a source for time-resolved pump-probe/two-color spectroscopy in the sub-50 fs range, which can be operated at 5 kHz or 10 kHz. An optical parametric amplifier is available for pump-probe experiments with wavelengths ranging from 240 nm to 20 000 nm. The produced XUV radiation is monochromatized by a grating in the so-called off-plane mount. Together with overall design parameters, first monochromatized spectra are shown with an intensity of 2 ⋅ 10{sup 10} photons/s (at 5 kHz) in the 29th harmonic, after the monochromator. The XUV pulse duration is measured to be <25 fs after monochromatization.

  11. Extreme ultraviolet and soft X-ray imaging with compact, table top laser plasma EUV and SXR sources

    NASA Astrophysics Data System (ADS)

    Wachulak, P. W.; Bartnik, A.; Kostecki, J.; Wegrzynski, L.; Fok, T.; Jarocki, R.; Szczurek, M.; Fiedorowicz, H.

    2015-12-01

    We present a few examples of imaging experiments, which were possible using a compact laser-plasma extreme ultraviolet (EUV) and soft X-ray (SXR) source, based on a double stream gas puff target. This debris-free source was used in full-field EUV imaging to obtain magnified images of test samples, ZnO nanofibers and images of the membranes coated with salt crystals. The source was also employed for SXR microscopy in the "water-window" spectral range using grazing incidence Wolter type-I objective to image test samples and to perform the initial studies of biological objects. Gas puff target EUV source, spectrally tuned for 13.5 nm wavelength with multilayer mirror and thin film filters, was also used in variety of shadowgraphy experiments to study the density of newly developed modulated density gas puff targets. Finally, the source was also employed in EUV tomography experiments of low density objects with the goal to measure and optimize the density of the targets dedicated to high harmonic generation.

  12. Damage Free Particle Removal from Extreme Ultraviolet Lithography Mask Layers by High Energy Laser Shock Wave Cleaning

    NASA Astrophysics Data System (ADS)

    Kim, Tae-Gon; Yoo, Young-Sam; Kim, Tae-Geun; Ahn, Jinho; Lee, Jong-Myoung; Choi, Jae-Sung; Busnaina, Ahmed A.; Park, Jin-Goo

    2008-06-01

    Plasma shock waves induced by focusing a Q-switched Nd:YAG laser at a maximum energy of 1.8 J in air were characterized by a laser beam deflection method and were applied to 50 nm silica particle removal from a Al2O3/TaN/Ru/MoSi 40 pairs as the extreme ultraviolet lithography (EUVL) mask layers on silicon wafer. A high energy laser induced shock wave effectively removed 50 nm silica particles from the EUVL mask layers. The change of sample topography before and after laser shock cleaning was measured by an atomic force microscope. Surface damage was observed at a gap distance of 1.5 mm. The dimensions of the plasma plume were characterized as a function of the laser energy and focus-to-surface gap distance. The plasma plume was the main source for damaging the surface. A high energy laser induced shock wave with a gap distance of over 3 mm achieved damage-free sub-100 nm particle removal.

  13. Charge Transfer Dissociation of Complex Oligosaccharides: Comparison with Collision-Induced Dissociation and Extreme Ultraviolet Dissociative Photoionization

    NASA Astrophysics Data System (ADS)

    Ropartz, David; Li, Pengfei; Fanuel, Mathieu; Giuliani, Alexandre; Rogniaux, Hélène; Jackson, Glen P.

    2016-10-01

    The structural characterization of oligosaccharides still challenges the field of analytical chemistry. Tandem mass spectrometry offers many advantages toward this aim, although the generic fragmentation method (low-energy collision-induced dissociation) shows clear limitations and is often insufficient to retrieve some essential structural information on these molecules. In this work, we present the first application of helium charge transfer dissociation (He-CTD) to characterize the structure of complex oligosaccharides. We compare this method with low-energy collision-induced dissociation and extreme-ultraviolet dissociative photoionization (XUV-DPI), which was shown previously to ensure the successful characterization of complex glycans. Similarly to what could be obtained by XUV-DPI, He-CTD provides a complete description of the investigated structures by producing many informative cross-ring fragments and no ambiguous fragmentation. Unlike XUV-DPI, which is performed at a synchrotron source, He-CTD has the undeniable advantage of being implementable in a conventional benchtop ion trap in a conventional laboratory setting.

  14. Spectroscopy of the extreme-ultraviolet source Feige 24 - The binary orbit and the mass of the white dwarf

    NASA Technical Reports Server (NTRS)

    Thorstensen, J. R.; Charles, P. A.; Bowyer, S.; Margon, B.

    1978-01-01

    Results are reported for coude spectroscopy of the extreme-ultraviolet white dwarf Feige 24. Radial velocities of the H-alpha, He I 5876-A, and He I 6678-A emission lines, and the underlying M-dwarf absorption features, were determined from spectrograms obtained with the Lick 3-m telescope. The velocities show a binary period of 4.239(+ or - 0.0015) days. The emission-line and absorption-line velocities agree in phase, which indicates that the emission lines originate in the atmosphere of the M-dwarf secondary as a result of reprocessing of the EUV radiation. This effect is modeled, and the observed amplitude of the emission-line variability is used to place a lower limit on the orbital inclination. From these and other data it is shown that the mass of the white dwarf lies between 0.46 and 1.24 solar masses. Some possible implications for the evolution of binary stars are briefly discussed.

  15. Characterization of carbon contamination under ion and hot atom bombardment in a tin-plasma extreme ultraviolet light source

    NASA Astrophysics Data System (ADS)

    Dolgov, A.; Lopaev, D.; Lee, C. J.; Zoethout, E.; Medvedev, V.; Yakushev, O.; Bijkerk, F.

    2015-10-01

    Molecular contamination of a grazing incidence collector for extreme ultraviolet (EUV) lithography was experimentally studied. A carbon film was found to have grown under irradiation from a pulsed tin plasma discharge. Our studies show that the film is chemically inert and has characteristics that are typical for a hydrogenated amorphous carbon film. It was experimentally observed that the film consists of carbon (∼70 at.%), oxygen (∼20 at.%) and hydrogen (bound to oxygen and carbon), along with a few at.% of tin. Most of the oxygen and hydrogen are most likely present as OH groups, chemically bound to carbon, indicating an important role for adsorbed water during the film formation process. It was observed that the film is predominantly sp3 hybridized carbon, as is typical for diamond-like carbon. The Raman spectra of the film, under 514 and 264 nm excitation, are typical for hydrogenated diamond-like carbon. Additionally, the lower etch rate and higher energy threshold in chemical ion sputtering in H2 plasma, compared to magnetron-sputtered carbon films, suggests that the film exhibits diamond-like carbon properties.

  16. Critical dimension uniformity and contact edge roughness in extreme ultraviolet lithography: effect of photoacid generator, sensitizer and quencher

    NASA Astrophysics Data System (ADS)

    Kuppuswamy, Vijaya-Kumar Murugesan; Constantoudis, Vassilios; Gogolides, Evangelos; Pret, Alessandro Vaglio; Gronheid, Roel

    2013-04-01

    One of the main challenges for developing extreme ultraviolet resists is to satisfy critical dimension uniformity (CDU) and sidewall roughness of contacts to the allowable limit. To this end, further understanding of the effects of resist ingredients on CDU and contact edge roughness (CER) is required. We investigate the effects of a photoacid generator (PAG), sensitizer and quencher concentrations on the CDU and CER. We find that the dependencies of CDU on sensitizer and quencher are dominated by photon shot noise (PSN) effects whereas a more complicated interplay between PSN and PAG distribution statistics should be considered in the dependence of CDU on PAG concentration. The estimated CER parameters [root mean square (RMS) value and correlation length ξ] exhibit a merging trend when plotted against the final critical dimension (CD). In addition, RMS value increases with exposure dose and PAG loading contrary to shot noise expectations. Power spectrum analysis reveals the dominant contribution of low-frequency undulations to CER, which is attributed to the enhanced interaction along specific directions between the aerial image and/or acid kinetics of nearby contacts. This inter-contact effect is further intensified with CD for fixed pitch and may explain the observed CER behavior.

  17. MAGNETIC RECONNECTION: FROM 'OPEN' EXTREME-ULTRAVIOLET LOOPS TO CLOSED POST-FLARE ONES OBSERVED BY SDO

    SciTech Connect

    Zhang, Jun; Yang, Shuhong; Li, Ting; Zhang, Yuzong; Li, Leping; Jiang, Chaowei E-mail: shuhongyang@nao.cas.cn E-mail: yuzong@nao.cas.cn E-mail: cwjiang@spaceweather.ac.cn

    2013-10-10

    We employ Solar Dynamics Observatory observations and select three well-observed events including two flares and one extreme-ultraviolet (EUV) brightening. During the three events, the EUV loops clearly changed. One event was related to a major solar flare that took place on 2012 July 12 in active region NOAA AR 11520. 'Open' EUV loops rooted in a facula of the AR deflected to the post-flare loops and then merged with them while the flare ribbon approached the facula. Meanwhile, 'open' EUV loops rooted in a pore disappeared from top to bottom as the flare ribbon swept over the pore. The loop evolution was similar in the low-temperature channels (e.g., 171 Å) and the high-temperature channels (e.g., 94 Å). The coronal magnetic fields extrapolated from the photospheric vector magnetograms also show that the fields apparently 'open' prior to the flare become closed after it. The other two events were associated with a B1.1 flare on 2010 May 24 and an EUV brightening on 2013 January 03, respectively. During both of these two events, some 'open' loops either disappeared or darkened before the formation of new closed loops. We suggest that the observations reproduce the picture predicted by the standard magnetic reconnection model: 'open' magnetic fields become closed due to reconnection, manifesting as a transformation from 'open' EUV loops to closed post-flare ones.

  18. Application of natural linear polysaccharide to green resist polymers for electron beam and extreme-ultraviolet lithography

    NASA Astrophysics Data System (ADS)

    Takei, Satoshi; Oshima, Akihiro; Oyama, Tomoko G.; Ito, Kenta; Sugahara, Kigen; Kashiwakura, Miki; Kozawa, Takahiro; Tagawa, Seiichi; Hanabata, Makoto

    2014-11-01

    The application of natural linear polysaccharide to green resist polymers was demonstrated for electron beam (EB) and extreme-ultraviolet (EUV) lithography using organic-solvent-free water spin-coating and tetramethylammonium hydroxide (TMAH)-free water-developable techniques. The water spin-coating and water-developable processes in a green resist material were carried out on wafers because of the water solubility of natural polysaccharides for an environmentally friendly manufacturing process for next-generation electronic devices. The developed green resist material with a weight-average molecular weight of 83,000 and 70 mol % hydroxyl groups as a water-developable feature was found to have acceptable properties such as spin-coat ability on 200 mm wafers, prediction sensitivity to EUV at the wavelengths of 6.7 and 13.5 nm, a high contrast of the water dissolution rate before and after EB irradiation, pillar patterns of 100-400 nm with a high EB sensitivity of 10 µC/cm2, and etch selectivity with a silicon-based middle layer in CF4 plasma treatment.

  19. Enhanced defect detection capability using learning system for extreme ultraviolet lithography mask inspection tool with projection electron microscope optics

    NASA Astrophysics Data System (ADS)

    Hirano, Ryoichi; Hatakeyama, Masahiro; Terao, Kenji; Watanabe, Hidehiro

    2016-04-01

    Extreme ultraviolet lithography (EUVL) patterned mask defect detection is a major issue that must be addressed to realize EUVL-based device fabrication. We have designed projection electron microscope (PEM) optics for integration into a mask inspection system, and the resulting PEM system performs well in half-pitch (hp) 16-nm-node EUVL patterned mask inspection applications. A learning system has been used in this PEM patterned mask inspection tool. The PEM identifies defects using the "defectivity" parameter that is derived from the acquired image characteristics. The learning system has been developed to reduce the labor and the costs associated with adjustment of the PEM's detection capabilities to cope with newly defined mask defects. The concepts behind this learning system and the parameter optimization flow are presented here. The learning system for the PEM is based on a library of registered defects. The learning system then optimizes the detection capability by reconciling previously registered defects with newly registered defects. Functional verification of the learning system is also described, and the system's detection capability is demonstrated by applying it to the inspection of hp 11-nm EUV masks. We can thus provide a user-friendly mask inspection system with reduced cost of ownership.

  20. Extreme ultraviolet patterned mask inspection performance of advanced projection electron microscope system for 11nm half-pitch generation

    NASA Astrophysics Data System (ADS)

    Hirano, Ryoichi; Iida, Susumu; Amano, Tsuyoshi; Watanabe, Hidehiro; Hatakeyama, Masahiro; Murakami, Takeshi; Suematsu, Kenichi; Terao, Kenji

    2016-03-01

    Novel projection electron microscope optics have been developed and integrated into a new inspection system named EBEYE-V30 ("Model EBEYE" is an EBARA's model code) , and the resulting system shows promise for application to half-pitch (hp) 16-nm node extreme ultraviolet lithography (EUVL) patterned mask inspection. To improve the system's inspection throughput for 11-nm hp generation defect detection, a new electron-sensitive area image sensor with a high-speed data processing unit, a bright and stable electron source, and an image capture area deflector that operates simultaneously with the mask scanning motion have been developed. A learning system has been used for the mask inspection tool to meet the requirements of hp 11-nm node EUV patterned mask inspection. Defects are identified by the projection electron microscope system using the "defectivity" from the characteristics of the acquired image. The learning system has been developed to reduce the labor and costs associated with adjustment of the detection capability to cope with newly-defined mask defects. We describe the integration of the developed elements into the inspection tool and the verification of the designed specification. We have also verified the effectiveness of the learning system, which shows enhanced detection capability for the hp 11-nm node.

  1. Alternate charging profiles for the onboard nickel cadmium batteries of the Explorer Platform/Extreme Ultraviolet Explorer

    NASA Technical Reports Server (NTRS)

    Rao, Gopalakrishna M.; Prettyman-Lukoschek, Jill S.

    1995-01-01

    The Explorer Platform/Extreme Ultraviolet Explorer (EP/EUVE) spacecraft power is provided by the Modular Power Subsystems (MPS) which contains three 50 ampere-hour Nickel Cadmium (NiCd) batteries. The batteries were fabricated by McDonnell Douglas Electronics Systems Company, with the cells fabricated by Gates Aerospace Batteries (GAB), Gainesville, Florida. Shortly following launch, the battery performance characteristics showed similar signatures as the anomalous performance observed on both the Upper Atmosphere Research Satellite (UARS) and the Compton Gamma Ray Observatory (CGRO). This prompted the development and implementation of alternate charging profiles to optimize the spacecraft battery performance. The Flight Operations Team (FOT), under the direction of Goddard Space Flight Center's (GSFC) EP/EUVE Project and Space Power Applications Branch have monitored and managed battery performance through control of the battery Charge to Discharge (C/D) ratio and implementation of a Solar Array (SA) offset. This paper provides a brief overview of the EP/EUVE mission, the MPS, the FOT's battery management for achieving the alternate charging profile, and the observed spacecraft battery performance.

  2. Design of anamorphic magnification high-numerical aperture objective for extreme ultraviolet lithography by curvatures combination method.

    PubMed

    Liu, Yan; Li, Yanqiu; Cao, Zhen

    2016-06-20

    An anamorphic magnification extreme ultraviolet (EUV) lithographic objective could increase the size of the exposure field at a wafer in the orthogonal scanning direction to improve the throughput of the lithographic system. In this paper, we present a curvatures combination method for an anamorphic magnification EUV lithographic objective with high numerical aperture (NA). This method achieves an anamorphic magnification initial structure by use of the double-curvature surfaces, which are formed by combining the curvatures of the corresponding surfaces into two coaxial spherical systems. A series of control measures is taken to design the two coaxial spherical systems for ensuring the rationalities of the initial structure and the surfaces after combining. The image quality of the anamorphic initial structure is optimized by a gradual optimization process. Finally, as an example, we design an Mx1/4 and My1/8 anamorphic magnification EUV lithographic objective with the presented design method. This objective achieves 0.5 NA and a 26  mm×16.5  mm exposure field at the wafer. The wavefront error RMS reaches 0.06λ (λ=13.5  nm), and the distortion is less than 2.8 nm. The design result proves the availability of the curvatures combination method.

  3. Soft X-ray irradiance measured by the Solar Aspect Monitor on the Solar Dynamic Observatory Extreme ultraviolet Variability Experiment

    NASA Astrophysics Data System (ADS)

    Lin, C. Y.; Bailey, S. M.; Jones, A.; Woodraska, D.; Caspi, A.; Woods, T. N.; Eparvier, F. G.; Wieman, S. R.; Didkovsky, L. V.

    2016-04-01

    The Solar Aspect Monitor (SAM) is a pinhole camera on the Extreme ultraviolet Variability Experiment (EVE) aboard the Solar Dynamics Observatory. SAM projects the solar disk onto the CCD through a metallic filter designed to allow only solar photons shortward of 7 nm to pass. Contamination from energetic particles and out-of-band irradiance is, however, significant in the SAM observations. We present a technique for isolating the 0.01-7 nm integrated irradiance from the SAM signal to produce the first results of broadband irradiance for the time period from May 2010 to May 2014. The results of this analysis agree with a similar data product from EVE's EUV SpectroPhotometer to within 25%. We compare our results with measurements from the Student Nitric Oxide Explorer Solar X-ray Photometer and the Thermosphere Ionosphere Mesosphere Energetics and Dynamics Solar EUV Experiment at similar levels of solar activity. We show that the full-disk SAM broadband results compared well to the other measurements of the 0.01-7 nm irradiance. We also explore SAM's capability toward resolving spatial contribution from regions of solar disk in irradiance and demonstrate this feature with a case study of several strong flares that erupted from active regions on 11 March 2011.

  4. Laser plasma sources of soft x-rays and extreme ultraviolet (EUV) for application in science and technology

    NASA Astrophysics Data System (ADS)

    Bartnik, Andrzej; Wachulak, Przemysław; Jarocki, Roman; Kostecki, Jerzy; Szczurek, Mirosław; Adjei, Daniel; Ahad, Inam Ul; Ayele, Mesfin G.; Fok, Tomasz; Szczurek, Anna; Torrisi, Alfio; Wegrzyński, Łukasz; Fiedorowicz, Henryk

    2015-05-01

    Laser plasma sources of soft x-rays and extreme ultraviolet (EUV) developed in our laboratory for application in various areas of technology and science are presented. The sources are based on a laser-irradiated gas puff target approach. The targets formed by pulsed injection of gas under high-pressure are irradiated with nanosecond laser pulses from Nd:YAG lasers. We use commercial lasers generating pulses with time duration from 1ns to 10ns and energies from 0.5J to 10J at 10Hz repetition rate. The gas puff targets are produced using a double valve system equipped with a special nozzle to form a double-stream gas puff target which secures high conversion efficiency without degradation of the nozzle. The use of a gas puff target instead of a solid target makes generation of laser plasmas emitting soft x-rays and EUV possible without target debris production. The sources are equipped with various optical systems, including grazing incidence axisymmetric ellipsoidal mirrors, a "lobster eye" type grazing incidence multi-foil mirror, and an ellipsoidal mirror with Mo/Si multilayer coating, to collect soft x-ray and EUV radiation and form the radiation beams. In this paper new applications of these sources in various fields, including soft x-ray and EUV imaging in nanoscale, EUV radiography and tomography, EUV materials processing and modification of polymer surfaces, EUV photoionization of gases, radiobiology and soft x-ray contact microscopy are reviewed.

  5. Tuning extreme ultraviolet emission for optimum coupling with multilayer mirrors for future lithography through control of ionic charge states

    SciTech Connect

    Ohashi, Hayato Higashiguchi, Takeshi Suzuki, Yuhei; Kawasaki, Masato; Li, Bowen; Dunne, Padraig; O'Sullivan, Gerry; Kanehara, Tatsuhiko; Aida, Yuya; Nakamura, Nobuyuki; Torii, Shuichi; Makimura, Tetsuya; Jiang, Weihua

    2014-01-21

    We report on the identification of the optimum plasma conditions for a laser-produced plasma source for efficient coupling with multilayer mirrors at 6.x nm for beyond extreme ultraviolet lithography. A small shift to lower energies of the peak emission for Nd:YAG laser-produced gadolinium plasmas was observed with increasing laser power density. Charge-defined emission spectra were observed in electron beam ion trap (EBIT) studies and the charge states responsible identified by use of the flexible atomic code (FAC). The EBIT spectra displayed a larger systematic shift of the peak wavelength of intense emission at 6.x nm to longer wavelengths with increasing ionic charge. This combination of spectra enabled the key ion stage to be confirmed as Gd{sup 18+}, over a range of laser power densities, with contributions from Gd{sup 17+} and Gd{sup 19+} responsible for the slight shift to longer wavelengths in the laser-plasma spectra. The FAC calculation also identified the origin of observed out-of-band emission and the charge states responsible.

  6. All About EVE: Education and Public Outreach for the Extreme Ultraviolet Variability Experiment (EVE) of the NASA Solar Dynamic Observatory

    NASA Astrophysics Data System (ADS)

    Eparvier, F. G.; McCaffrey, M. S.; Buhr, S. M.

    2008-12-01

    With the aim of meeting NASA goals for education and public outreach as well as support education reform efforts including the National Science Education Standards, a suite of education materials and strategies have been developed by the Cooperative Institute for Environmental Sciences (CIRES) with the Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado for the Extreme Ultraviolet Variability Experiment (EVE), which is an instrument aboard the Solar Dynamic Observatory. This paper will examine the education materials that have been developed for teachers in the classroom and scientists who are conducting outreach, including handouts, a website on space weather for teachers, a slideshow presentation about the overall Solar Dynamic Observatory mission, and a DVD with videos explaining the construction and goals of the EVE instrument, a tour of LASP, and an overview of space science careers. The results and potential transferability of a pilot project developed through this effort that engaged English Second Language learners in a semester-long course on space weather that incorporated the used of a Sudden Ionospheric Disturbance (SID) Monitor will be highlighted.

  7. An Upper Limit on the Ratio Between the Extreme Ultraviolet and the Bolometric Luminosities of Stars Hosting Habitable Planets

    NASA Astrophysics Data System (ADS)

    Sengupta, Sujan

    2016-06-01

    A large number of terrestrial planets in the classical habitable zone of stars of different spectral types have already been discovered and many are expected to be discovered in the near future. However, owing to the lack of knowledge on the atmospheric properties, the ambient environment of such planets are unknown. It is known that sufficient amount of Extreme Ultraviolet (EUV) radiation from the star can drive hydrodynamic outflow of hydrogen that may drag heavier species from the atmosphere of the planet. If the rate of mass loss is sufficiently high, then substantial amount of volatiles would escape causing the planet to become uninhabitable. Considering energy-limited hydrodynamical mass loss with an escape rate that causes oxygen to escape alongwith hydrogen, an upper limit for the ratio between the EUV and the bolometric luminosities of stars which constrains the habitability of planets around them is presented here. Application of the limit to planet-hosting stars with known EUV luminosities implies that many M-type of stars should not have habitable planets around them.

  8. Spectral investigations of photoionized plasmas induced in atomic and molecular gases using nanosecond extreme ultraviolet (EUV) pulses

    SciTech Connect

    Bartnik, A.; Fiedorowicz, H.; Wachulak, P.

    2014-07-15

    In this paper, results of spectral investigations of low temperature photoionized plasmas, created by irradiation of gases with intense pulses of extreme ultraviolet (EUV) radiation from a laser-produced plasma (LPP) source, are presented. The LPP source was based on a double-stream KrXe/He gas-puff target irradiated with 4 ns/0.8 J/10 Hz Nd:YAG laser pulses. The most intense emission from the source spanned a relatively narrow spectral region λ ≈ 10–12 nm; however, spectrally integrated intensity at longer wavelengths was also significant. The EUV beam was focused on a gas stream, injected into a vacuum chamber synchronously with the EUV pulses. Irradiation of gases resulted in formation of photoionized plasmas emitting radiation in the EUV range. Radiation spectra, measured for plasmas produced in various gases, are dominated by emission lines, originating from single charged ions. Significant differences in spectral intensities and distributions between plasmas created in neon and molecular gases were observed.

  9. DIFFRACTION, REFRACTION, AND REFLECTION OF AN EXTREME-ULTRAVIOLET WAVE OBSERVED DURING ITS INTERACTIONS WITH REMOTE ACTIVE REGIONS

    SciTech Connect

    Shen Yuandeng; Liu Yu; Zhao Ruijuan; Tian Zhanjun; Su Jiangtao; Li Hui; Ichimoto, Kiyoshi; Shibata, Kazunari

    2013-08-20

    We present observations of the diffraction, refraction, and reflection of a global extreme-ultraviolet (EUV) wave propagating in the solar corona. These intriguing phenomena are observed when the wave interacts with two remote active regions, and together they exhibit properties of an EUV wave. When the wave approached AR11465, it became weaker and finally disappeared in the active region, but a few minutes later a new wavefront appeared behind the active region, and it was not concentric with the incoming wave. In addition, a reflected wave was also simultaneously observed on the wave incoming side. When the wave approached AR11459, it transmitted through the active region directly and without reflection. The formation of the new wavefront and the transmission could be explained with diffraction and refraction effects, respectively. We propose that the different behaviors observed during the interactions may be caused by different speed gradients at the boundaries of the two active regions. We find that the EUV wave formed ahead of a group of expanding loops a few minutes after the start of the loops' expansion, which represents the initiation of the associated coronal mass ejection (CME). Based on these results, we conclude that the EUV wave should be a nonlinear magnetosonic wave or shock driven by the associated CME, which propagated faster than the ambient fast mode speed and gradually slowed down to an ordinary linear wave. Our observations support the hybrid model that includes both fast wave and slow non-wave components.

  10. Investigation of the interaction of a laser pulse with a preformed Gaussian Sn plume for an extreme ultraviolet lithography source

    SciTech Connect

    Tao, Y.; Tillack, M. S.; Harilal, S. S.; Sequoia, K. L.; Najmabadi, F.

    2007-01-15

    The interaction of a laser pulse with a Sn preplasma formed by a low energy prepulse was investigated for an extreme ultraviolet (EUV) lithography light source. A much lower ion kinetic energy and nearly the same conversion efficiency from laser to in-band (2% bandwidth) 13.5 nm EUV light were simultaneously observed as compared with those from the direct interaction with a solid surface. The reason comes from the interaction of the laser pulse with a smooth preplume induced by the prepulse. The density profile of the preplume was measured with time-resolved shadowgraphy and could be fitted with a Gaussian function. The energy of the ions located at the flux peak E{sub p} scales with the length of the preplume l{sub s} as E{sub p}{proportional_to}1/l{sub s}. Laser absorption in the low-density preplume and ion acceleration during plasma expansion are discussed. This result provides a general way to control particle energy from a laser plasma interaction.

  11. Different oxidative stress response in keratinocytes and fibroblasts of reconstructed skin exposed to non extreme daily-ultraviolet radiation.

    PubMed

    Marionnet, Claire; Pierrard, Cécile; Lejeune, François; Sok, Juliette; Thomas, Marie; Bernerd, Françoise

    2010-08-10

    Experiments characterizing the biological effects of sun exposure have usually involved solar simulators. However, they addressed the worst case scenario i.e. zenithal sun, rarely found in common outdoor activities. A non-extreme ultraviolet radiation (UV) spectrum referred as "daily UV radiation" (DUVR) with a higher UVA (320-400 nm) to UVB (280-320 nm) irradiance ratio has therefore been defined. In this study, the biological impact of an acute exposure to low physiological doses of DUVR (corresponding to 10 and 20% of the dose received per day in Paris mid-April) on a 3 dimensional reconstructed skin model, was analysed. In such conditions, epidermal and dermal morphological alterations could only be detected after the highest dose of DUVR. We then focused on oxidative stress response induced by DUVR, by analyzing the modulation of mRNA level of 24 markers in parallel in fibroblasts and keratinocytes. DUVR significantly modulated mRNA levels of these markers in both cell types. A cell type differential response was noticed: it was faster in fibroblasts, with a majority of inductions and high levels of modulation in contrast to keratinocyte response. Our results thus revealed a higher sensitivity in response to oxidative stress of dermal fibroblasts although located deeper in the skin, giving new insights into the skin biological events occurring in everyday UV exposure.

  12. Quantitative analysis of electron energy loss spectra and modelling of optical properties of multilayer systems for extreme ultraviolet radiation regime

    SciTech Connect

    Gusenleitner, S.; Hauschild, D.; Reinert, F.; Handick, E.

    2014-03-28

    Ruthenium capped multilayer coatings for use in the extreme ultraviolet (EUV) radiation regime have manifold applications in science and industry. Although the Ru cap shall protect the reflecting multilayers, the surface of the heterostructures suffers from contamination issues and surface degradation. In order to get a better understanding of the effects of these impurities on the optical parameters, reflection electron energy loss spectroscopy (REELS) measurements of contaminated and H cleaned Ru multilayer coatings were taken at various primary electron beam energies. Experiments conducted at low primary beam energies between 100 eV and 1000 eV are very surface sensitive due to the short inelastic mean free path of the electrons in this energy range. Therefore, influences of the surface condition on the above mentioned characteristics can be appraised. In this paper, it can be shown that carbon and oxide impurities on the mirror surface decrease the transmission of the Ru cap by about 0.75% and the overall reflectance of the device is impaired as the main share of the non-transmitted EUV light is absorbed in the contamination layer.

  13. Theoretical study of relationships among resolution, line width roughness, and sensitivity of chemically amplified extreme ultraviolet resists with photodecomposable quenchers

    NASA Astrophysics Data System (ADS)

    Kozawa, Takahiro; Santillan, Julius Joseph; Itani, Toshiro

    2016-11-01

    The resolution of chemically amplified extreme ultraviolet (EUV) resists has reached 13-15 nm. However, the line width roughness (LWR) and sensitivity are still inadequate for their application to the high-volume production of semiconductor devices. In this study, the performance of chemically amplified resists with photodecomposable quenchers were investigated by simulation based on the sensitization and reaction mechanisms of chemically amplified EUV resists. The relationships among resolution, LWR, and sensitivity were evaluated in the half-pitch ranges of 12-16 nm. The requirements for 20 mJ cm-2 and 10% critical dimension (CD) LWR are considered to be within the physical limits in the half-pitch range of 12-16 nm when an optical image with a contrast of 1 (normalized image log slope of π) is given. Depending on the given image quality and the required sensitivity, the optimization of sensitizer concentration and the increase in resist absorption coefficient and/or effective reaction radius for deprotection are required to achieve 10% CD LWR.

  14. Wolter-Schwarzschild optics for the extreme-ultraviolet - The Berkeley stellar spectrometer and the EUV Explorer

    NASA Technical Reports Server (NTRS)

    Malina, R. F.; Bowyer, S.; Finley, D.; Cash, W.

    1979-01-01

    The design, fabrication and performance of two Wolter-Schwarzschild grazing incidence optics are described. Both telescopes have been figured by single point diamond turning and have achieved better than 15-arcsec on-axis imaging. The telescope for the stellar spectrometer is an f/10 Type II system with an effective area of 225 sq cm at 250 A and 300 cm2 at 500 A. The primary has a maximum diameter of 38 cm and was fabricated in three elements. The copper-plated aluminum substrate was diamond turned; following nickel plating, the surface was polished and coated with evaporated gold. The performance during a sounding rocket flight is discussed. The prototype telescope for the Extreme Ultraviolet Explorer is an f/1.24 Type I system with an effective field of view of 5.0-deg diameter. The telescope has a maximum diameter of 40 cm and was fabricated as a single element. The aluminum substrate is to be diamond turned; the nickel plated surface will be polished and electroplated with gold. The design choice and defocusing optimization aimed at maximizing the field of view and number of image pixels is examined.

  15. HELIOS--A laboratory based on high-order harmonic generation of extreme ultraviolet photons for time-resolved spectroscopy.

    PubMed

    Plogmaker, S; Terschlüsen, J A; Krebs, N; Svanqvist, M; Forsberg, J; Cappel, U B; Rubensson, J-E; Siegbahn, H; Söderström, J

    2015-12-01

    In this paper, we present the HELIOS (High Energy Laser Induced Overtone Source) laboratory, an in-house high-order harmonic generation facility which generates extreme ultraviolet (XUV) photon pulses in the range of 15-70 eV with monochromatized XUV pulse lengths below 35 fs. HELIOS is a source for time-resolved pump-probe/two-color spectroscopy in the sub-50 fs range, which can be operated at 5 kHz or 10 kHz. An optical parametric amplifier is available for pump-probe experiments with wavelengths ranging from 240 nm to 20,000 nm. The produced XUV radiation is monochromatized by a grating in the so-called off-plane mount. Together with overall design parameters, first monochromatized spectra are shown with an intensity of 2 ⋅ 10(10) photons/s (at 5 kHz) in the 29th harmonic, after the monochromator. The XUV pulse duration is measured to be <25 fs after monochromatization.

  16. Electron-induced interaction of selected hydrocarbons with TiO2 surfaces: the relevance to extreme ultraviolet lithography.

    PubMed

    Yakshinskiy, B V; Zalkind, S; Bartynski, R A; Caudillo, R

    2010-03-03

    The aim of this work is to characterize desorption induced by electronic transition processes that affect the reflectivity of TiO2-capped multilayer mirrors used in extreme ultraviolet (EUV) lithography. A low energy electron beam is employed to mimic excitations initiated by EUV radiation. Temperature programmed desorption, x-ray photoelectron spectroscopy, and low energy ion scattering are used to analyze the surface reactions. Carbon film growth on the TiO2(011) crystalline surface is measured during 10-100 eV electron bombardment in benzene or methyl methacrylate vapor over a wide range of pressures and temperatures near 300 K. Low energy secondary electrons excited by EUV photons contribute substantially to the carbon accumulation on clean TiO2 cap layers. For benzene on clean TiO2, secondary electron effects dominate in the initial stages of carbon accumulation, whereas for C-covered TiO2, direct excitations appear to dominate. We report on the adsorption energy, the steady-state coverage of the molecules on the surface and the cross sections for electron-stimulated dissociation: all key parameters for understanding and modeling the processes relating to the EUV lithography mirrors.

  17. Different Oxidative Stress Response in Keratinocytes and Fibroblasts of Reconstructed Skin Exposed to Non Extreme Daily-Ultraviolet Radiation

    PubMed Central

    Marionnet, Claire; Pierrard, Cécile; Lejeune, François; Sok, Juliette; Thomas, Marie; Bernerd, Françoise

    2010-01-01

    Experiments characterizing the biological effects of sun exposure have usually involved solar simulators. However, they addressed the worst case scenario i.e. zenithal sun, rarely found in common outdoor activities. A non-extreme ultraviolet radiation (UV) spectrum referred as “daily UV radiation” (DUVR) with a higher UVA (320–400 nm) to UVB (280–320 nm) irradiance ratio has therefore been defined. In this study, the biological impact of an acute exposure to low physiological doses of DUVR (corresponding to 10 and 20% of the dose received per day in Paris mid-April) on a 3 dimensional reconstructed skin model, was analysed. In such conditions, epidermal and dermal morphological alterations could only be detected after the highest dose of DUVR. We then focused on oxidative stress response induced by DUVR, by analyzing the modulation of mRNA level of 24 markers in parallel in fibroblasts and keratinocytes. DUVR significantly modulated mRNA levels of these markers in both cell types. A cell type differential response was noticed: it was faster in fibroblasts, with a majority of inductions and high levels of modulation in contrast to keratinocyte response. Our results thus revealed a higher sensitivity in response to oxidative stress of dermal fibroblasts although located deeper in the skin, giving new insights into the skin biological events occurring in everyday UV exposure. PMID:20706594

  18. Chemical Effect of Dry and Wet Cleaning of the Ru Protective Layer of the Extreme ultraviolet (EUV) Lithography Reflector

    SciTech Connect

    Belau, Leonid; Park, Jeong Y.; Liang, Ted; Seo, Hyungtak; Somorjai, Gabor A.

    2009-04-10

    The authors report the chemical influence of cleaning of the Ru capping layer on the extreme ultraviolet (EUV) reflector surface. The cleaning of EUV reflector to remove the contamination particles has two requirements: to prevent corrosion and etching of the reflector surface and to maintain the reflectivity functionality of the reflector after the corrosive cleaning processes. Two main approaches for EUV reflector cleaning, wet chemical treatments [sulfuric acid and hydrogen peroxide mixture (SPM), ozonated water, and ozonated hydrogen peroxide] and dry cleaning (oxygen plasma and UV/ozone treatment), were tested. The changes in surface morphology and roughness were characterized using scanning electron microscopy and atomic force microscopy, while the surface etching and change of oxidation states were probed with x-ray photoelectron spectroscopy. Significant surface oxidation of the Ru capping layer was observed after oxygen plasma and UV/ozone treatment, while the oxidation is unnoticeable after SPM treatment. Based on these surface studies, the authors found that SPM treatment exhibits the minimal corrosive interactions with Ru capping layer. They address the molecular mechanism of corrosive gas and liquid-phase chemical interaction with the surface of Ru capping layer on the EUV reflector.

  19. Easy Absolute Values? Absolutely

    ERIC Educational Resources Information Center

    Taylor, Sharon E.; Mittag, Kathleen Cage

    2015-01-01

    The authors teach a problem-solving course for preservice middle-grades education majors that includes concepts dealing with absolute-value computations, equations, and inequalities. Many of these students like mathematics and plan to teach it, so they are adept at symbolic manipulations. Getting them to think differently about a concept that they…

  20. Charge exchange recombination spectroscopy measurements in the extreme ultraviolet region of central carbon concentrations during high power neutral beam heating in TFTR (Tokamak Fusion Test Reactor)

    SciTech Connect

    Stratton, B.C.; Fonck, R.J.; Ramsey, A.T.; Synakowski, E.J.; Grek, B.; Hill, K.W.; Johnson, D.W.; Mansfield, D.K.; Park, H.; Taylor, G.; Valanju, P.M. . Plasma Physics Lab.; Texas Univ., Austin, TX . Fusion Research Center)

    1989-09-01

    The carbon concentration in the central region of TFTR discharges with high power neutral beam heating has been measured by charge-extracted recombination spectroscopy (CXRS) of the C{sup +5} n = 3--4 transition in the extreme ultraviolet region. The carbon concentrations were deduced from absolute measurements of the line brightness using a calculation of the beam attenuation and the appropriate cascade-corrected line excitation rates. As a result of the high ion temperatures in most of the discharges, the contribution of beam halo neutrals to the line brightness was significant and therefore had to be included in the modeling of the data. Carbon concentrations have been measured in discharges with I{sub p} = 1.0-1.6 MA and beam power in the range of 2.6-30 MW, including a number of supershots. The results are in good agreement with carbon concentrations deduced from the visible bremsstrahlung Z{sub eff} and metallic impurity concentrations measured by x-ray pulse-height analysis, demonstrating the reliability of the atomic rates used in the beam attenuation and line excitation calculations. Carbon is the dominant impurity species in these discharges; the oxygen concentration measured via CXRS in a high beam power case was 0.0006 of n{sub e}, compard to 0.04 for carbon. Trends with I{sub p} and beam power in the carbon concentration and the inferred deuteron concentration are presented. The carbon concentration is independent of I{sub p} and decreases from 0.13 at 2.6 MW beam power to 0.04 at 30 MW, while the deuteron concentration increases from 0.25 to 0.75 over the same range of beam power. These changes are primarily the result of beam particle fueling, as the carbon density did not vary significantly with beam power. The time evolutions of the carbon and deuteron concentrations during two high power beam pulses, one which exhibited a carbon bloom and one which did not, are compared. 30 refs., 12 figs., 2 tabs.

  1. Space-resolved extreme ultraviolet spectroscopy free of high-energy neutral particle noise in wavelength range of 10-130 Å on the large helical device

    NASA Astrophysics Data System (ADS)

    Huang, Xianli; Morita, Shigeru; Oishi, Tetsutarou; Goto, Motoshi; Dong, Chunfeng

    2014-04-01

    A flat-field space-resolved extreme ultraviolet (EUV) spectrometer system working in wavelength range of 10-130 Å has been constructed in the Large Helical Device (LHD) for profile measurements of bremsstrahlung continuum and line emissions of heavy impurities in the central column of plasmas, which are aimed at studies on Zeff and impurity transport, respectively. Until now, a large amount of spike noise caused by neutral particles with high energies (≤180 keV) originating in neutral beam injection has been observed in EUV spectroscopy on LHD. The new system has been developed with an aim to delete such a spike noise from the signal by installing a thin filter which can block the high-energy neutral particles entering the EUV spectrometer. Three filters of 11 μm thick beryllium (Be), 3.3 μm thick polypropylene (PP), and 0.5 μm thick polyethylene terephthalate (PET: polyester) have been examined to eliminate the spike noise. Although the 11 μm Be and 3.3 μm PP filters can fully delete the spike noise in wavelength range of λ ≤ 20 Å, the signal intensity is also reduced. The 0.5 μm PET filter, on the other hand, can maintain sufficient signal intensity for the measurement and the spike noise remained in the signal is acceptable. As a result, the bremsstrahlung profile is successfully measured without noise at 20 Å even in low-density discharges, e.g., 2.9 × 1013 cm-3, when the 0.5 μm PET filter is used. The iron n = 3-2 Lα transition array consisting of FeXVII to FeXXIV is also excellently observed with their radial profiles in wavelength range of 10-18 Å. Each transition in the Lα array can be accurately identified with its radial profile. As a typical example of the method a spectral line at 17.62 Å is identified as FeXVIII transition. Results on absolute intensity calibration of the spectrometer system, pulse height and noise count analyses of the spike noise between holographic and ruled gratings and wavelength response of the used filters

  2. Study of CD variation caused by the black border effect and out-of-band radiation in extreme ultraviolet lithography

    NASA Astrophysics Data System (ADS)

    Gao, Weimin; Niroomand, Ardavan; Lorusso, Gian F.; Boone, Robert; Lucas, Kevin; Demmerle, Wolfgang

    2014-04-01

    Although extreme ultraviolet lithography (EUVL) remains a promising candidate for semiconductor device manufacturing of the 1× nm half pitch node and beyond, many technological burdens have to be overcome. The "field edge effect" in EUVL is one of them. The image border region of an EUV mask, also known as the "black border" (BB), reflects a few percent of the incident EUV light, resulting in a leakage of light into neighboring exposure fields, especially at the corner of the field where three adjacent exposures take place. This effect significantly impacts on critical dimension (CD) uniformity (CDU) across the exposure field. To avoid this phenomenon, a light-shielding border is introduced by etching away the entire absorber and multilayer at the image border region of the EUV mask. We present a method of modeling the field edge effect (also called the BB effect) by using rigorous lithography simulation with a calibrated resist model. An additional "flare level" at the field edge is introduced on top of the exposure tool flare map to account for the BB effect. The parameters in this model include the reflectivity and the width of the BB, which are mainly determining the leakage of EUV light and its influence range, respectively. Another parameter is the transition width which represents the half shadow effect of the reticle masking blades. By setting the corresponding parameters, the simulation results match well the experimental results obtained at the IMEC's NXE:3100 EUV exposure tool. Moreover, these results indicate that the out-of-band (OoB) radiation also contributes to the CDU. Using simulation, we can also determine the OoB effect rigorously using the methodology of an "effective mask blank." The study demonstrates that the impact of BB and OoB effects on CDU can be well predicted by simulations.

  3. SLOW PATCHY EXTREME-ULTRAVIOLET PROPAGATING FRONTS ASSOCIATED WITH FAST CORONAL MAGNETO-ACOUSTIC WAVES IN SOLAR ERUPTIONS

    SciTech Connect

    Guo, Y.; Ding, M. D.; Chen, P. F.

    2015-08-15

    Using the high spatiotemporal resolution extreme ultraviolet (EUV) observations of the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory, we conduct a statistical study of the observational properties of the coronal EUV propagating fronts. We find that it might be a universal phenomenon for two types of fronts to coexist in a large solar eruptive event. It is consistent with the hybrid model of EUV propagating fronts, which predicts that coronal EUV propagating fronts consist of both a fast magneto-acoustic wave and a nonwave component. We find that the morphologies, propagation behaviors, and kinematic features of the two EUV propagating fronts are completely different from each other. The fast magneto-acoustic wave fronts are almost isotropic. They travel continuously from the flaring region across multiple magnetic polarities to global distances. On the other hand, the slow nonwave fronts appear as anisotropic and sequential patches of EUV brightening. Each patch propagates locally in the magnetic domains where the magnetic field lines connect to the bottom boundary and stops at the magnetic domain boundaries. Within each magnetic domain, the velocities of the slow patchy nonwave component are an order of magnitude lower than that of the fast-wave component. However, the patches of the slow EUV propagating front can jump from one magnetic domain to a remote one. The velocities of such a transit between different magnetic domains are about one-third to one-half of those of the fast-wave component. The results show that the velocities of the nonwave component, both within one magnetic domain and between different magnetic domains, are highly nonuniform due to the inhomogeneity of the magnetic field in the lower atmosphere.

  4. THE INFLUENCE OF THE EXTREME ULTRAVIOLET SPECTRAL ENERGY DISTRIBUTION ON THE STRUCTURE AND COMPOSITION OF THE UPPER ATMOSPHERE OF EXOPLANETS

    SciTech Connect

    Guo, J. H.; Ben-Jaffel, Lotfi E-mail: bjaffel@iap.fr

    2016-02-20

    By varying the profiles of stellar extreme ultraviolet (EUV) spectral energy distributions (SEDs), we tested the influences of stellar EUV SEDs on the physical and chemical properties of an escaping atmosphere. We apply our model to study four exoplanets: HD 189733b, HD 209458b, GJ 436b, and Kepler-11b. We find that the total mass loss rates of an exoplanet, which are determined mainly by the integrated fluxes, are moderately affected by the profiles of the EUV SED, but the composition and species distributions in the atmosphere can be dramatically modified by the different profiles of the EUV SED. For exoplanets with a high hydrodynamic escape parameter (λ), the amount of atomic hydrogen produced by photoionization at different altitudes can vary by one to two orders of magnitude with the variation of stellar EUV SEDs. The effect of photoionization of H is prominent when the EUV SED is dominated by the low-energy spectral region (400–900 Å), which pushes the transition of H/H{sup +} to low altitudes. In contrast, the transition of H/H{sup +} moves to higher altitudes when most photons are concentrated in the high-energy spectral region (50–400 Å). For exoplanets with a low λ, the lower temperatures of the atmosphere make many chemical reactions so important that photoionization alone can no longer determine the composition of the escaping atmosphere. For HD 189733b, it is possible to explain the time variability of Lyα between 2010 and 2011 by a change in the EUV SED of the host K-type star, yet invoking only thermal H i in the atmosphere.

  5. Development of extreme ultraviolet and soft x-ray multilayer optics for scientific studies with femtosecond/attosecond sources

    SciTech Connect

    Aquila, Andrew Lee

    2009-05-21

    The development of multilayer optics for extreme ultraviolet (EUV) radiation has led to advancements in many areas of science and technology, including materials studies, EUV lithography, water window microscopy, plasma imaging, and orbiting solar physics imaging. Recent developments in femtosecond and attosecond EUV pulse generation from sources such as high harmonic generation lasers, combined with the elemental and chemical specificity provided by EUV radiation, are opening new opportunities to study fundamental dynamic processes in materials. Critical to these efforts is the design and fabrication of multilayer optics to transport, focus, shape and image these ultra-fast pulses This thesis describes the design, fabrication, characterization, and application of multilayer optics for EUV femtosecond and attosecond scientific studies. Multilayer mirrors for bandwidth control, pulse shaping and compression, tri-material multilayers, and multilayers for polarization control are described. Characterization of multilayer optics, including measurement of material optical constants, reflectivity of multilayer mirrors, and metrology of reflected phases of the multilayer, which is critical to maintaining pulse size and shape, were performed. Two applications of these multilayer mirrors are detailed in the thesis. In the first application, broad bandwidth multilayers were used to characterize and measure sub-100 attosecond pulses from a high harmonic generation source and was performed in collaboration with the Max-Planck institute for Quantum Optics and Ludwig- Maximilians University in Garching, Germany, with Professors Krausz and Kleineberg. In the second application, multilayer mirrors with polarization control are useful to study femtosecond spin dynamics in an ongoing collaboration with the T-REX group of Professor Parmigiani at Elettra in Trieste, Italy. As new ultrafast x-ray sources become available, for example free electron lasers, the multilayer designs

  6. EXTREME-ULTRAVIOLET AND X-RAY OBSERVATIONS OF COMET LOVEJOY (C/2011 W3) IN THE LOWER CORONA

    SciTech Connect

    McCauley, Patrick I.; Saar, Steven H.; Raymond, John C.; Ko, Yuan-Kuen; Saint-Hilaire, Pascal

    2013-05-10

    We present an analysis of extreme-ultraviolet and soft X-ray emission detected toward Comet Lovejoy (C/2011 W3) during its post-perihelion traverse of the solar corona on 2011 December 16. Observations were recorded by the Atmospheric Imaging Assembly (AIA) aboard the Solar Dynamics Observatory and the X-Ray Telescope (XRT) aboard Hinode. A single set of contemporaneous images is explored in detail, along with prefatory consideration for time evolution using only the 171 A data. For each of the eight passbands, we characterize the emission and derive outgassing rates where applicable. As material sublimates from the nucleus and is immersed in coronal plasma, it rapidly ionizes through charge states seldom seen in this environment. The AIA data show four stages of oxygen ionization (O III-O VI) along with C IV, while XRT likely captured emission from O VII, a line typical of the corona. With a nucleus of at least several hundred meters upon approach to a perihelion that brought the comet to within 0.2 R{sub Sun} of the photosphere, Lovejoy was the most significant sungrazer in recent history. Correspondingly high outgassing rates on the order of 10{sup 32.5} oxygen atoms per second are estimated. Assuming that the neutral oxygen comes from water, this translates to a mass-loss rate of {approx}9.5 Multiplication-Sign 10{sup 9} g s{sup -1}, and based only on the 171 A observations, we find a total mass loss of {approx}10{sup 13} g over the AIA egress. Additional and supporting analyses include a differential emission measure to characterize the coronal environment, consideration for the opening angle, and a comparison of the emission's leading edge with the expected position of the nucleus.

  7. Fabrication of Thiol-Ene "Clickable" Copolymer-Brush Nanostructures on Polymeric Substrates via Extreme Ultraviolet Interference Lithography.

    PubMed

    Dübner, Matthias; Gevrek, Tugce N; Sanyal, Amitav; Spencer, Nicholas D; Padeste, Celestino

    2015-06-03

    We demonstrate a new approach to grafting thiol-reactive nanopatterned copolymer-brush structures on polymeric substrates by means of extreme ultraviolet (EUV) interference lithography. The copolymer brushes were designed to contain maleimide functional groups as thiol-reactive centers. Fluoropolymer films were exposed to EUV radiation at the X-ray interference lithography beamline (XIL-II) at the Swiss Light Source, in order to create radical patterns on their surfaces. The radicals served as initiators for the copolymerization of thiol-ene "clickable" brushes, composed of a furan-protected maleimide monomer (FuMaMA) and different methacrylates, namely, methyl methacrylate (MMA), ethylene glycol methyl ether methacrylate (EGMA), or poly(ethylene glycol) methyl ether methacrylate (PEGMA). Copolymerization with ethylene-glycol-containing monomers provides antibiofouling properties to these surfaces. The number of reactive centers on the grafted brush structures can be tailored by varying the monomer ratios in the feed. Grafted copolymers were characterized by using attenuated total reflection infrared (ATR-IR) spectroscopy. The reactive maleimide methacrylate (MaMA) units were utilized to conjugate thiol-containing moieties using the nucleophilic Michael-addition reaction, which proceeds at room temperature without the need for any metal-based catalyst. Using this approach, a variety of functionalities was introduced to yield polyelectrolytes, as well as fluorescent and light-responsive polymer-brush structures. Functionalization of the brush structures was demonstrated via ATR-IR and UV-vis spectroscopy and fluorescence microscopy, and was also indicated by a color switch. Furthermore, grafted surfaces were generated via plasma activation, showing a strongly increased wettability for polyelectrolytes and a reversible switch in static water contact angle (CA) of up to 18° for P(EGMA-co-MaMA-SP) brushes, upon exposure to alternating visible and UV-light irradiation.

  8. Soft x-ray microscopy and extreme ultraviolet lithography: Imaging in the 20-50 nm regime (abstract) (invited)

    NASA Astrophysics Data System (ADS)

    Attwood, David

    2002-03-01

    Advances in short wavelength optics, covering the range from 1 to 14 nm, are providing new results and new opportunities. Zone plate lenses [E. Anderson et al., J. Vac. Sci. Techno. B 18, 2970 (2000)] for soft x-ray microscopy [G. Denbeaux, Rev. Sci. Instrum. (these proceedings); W. Chao, Proc. SPIE 4146, 171 (2000)] are now made to high accuracy with outer zone widths of 25 nm, and demonstrated resolution of 23 nm with proper illumination and stability. These permit important advances in the study of protein specific transport and structure in the life sciences [C. Larabell (private communication); W. Meyer-Ilse et al., J. Microsc. 201, 395 (2001)] and the study of magnetic materials [P. Fischer et al., J. Synchrotron. Radiat. 8, 325 (2001)] with elemental sensitivity at the resolution of individual domains. Major corporations (members of the EUV Limited Liability Company are Intel, Motorola, AMD, Micron, Infineon, and IBM) are now preparing the path for the fabrication of future computer chips, in the years 2007 and beyond, using multilayer coated reflective optics, which achieve reflectivities of 70% in the 11-14 nm region [T. Barbee et al., Appl. Opt. 24, 883 (1985); C. Montcalm et al., Proc. SPIE 3676, 710 (1999)]. These coated optics are to be incorporated in extreme ultraviolet (EUV) print cameras, known as "steppers." Electronic patterns with features in the range of 50-70 nm have been printed. The first alpha tool stepper recently demonstrated all critical technologies [D. Tichenor et al., Proc. SPIE 4343, 19 (2001)] needed for EUV lithography. Preproduction beta tools are targeted for delivery by leading suppliers [ASML, the Netherlands, at the SPIE Microlithography Conference, Santa Clara, CA, March 2001] in 2004, with high volume production tools available in late 2006 for manufacturing in 2007. New results in these two areas will be discussed in the context of the synergy of science and technology.

  9. Non-Gaussian Velocity Distributions in Solar Flares from Extreme Ultraviolet Lines: A Possible Diagnostic of Ion Acceleration

    NASA Astrophysics Data System (ADS)

    Jeffrey, Natasha L. S.; Fletcher, Lyndsay; Labrosse, Nicolas

    2017-02-01

    In a solar flare, a large fraction of the magnetic energy released is converted rapidly to the kinetic energy of non-thermal particles and bulk plasma motion. This will likely result in non-equilibrium particle distributions and turbulent plasma conditions. We investigate this by analyzing the profiles of high temperature extreme ultraviolet emission lines from a major flare (SOL2014-03-29T17:44) observed by the EUV Imaging Spectrometer (EIS) on Hinode. We find that in many locations the line profiles are non-Gaussian, consistent with a kappa distribution of emitting ions with properties that vary in space and time. At the flare footpoints, close to sites of hard X-ray emission from non-thermal electrons, the κ index for the Fe xvi 262.976 Å line at 3 MK takes values of 3–5. In the corona, close to a low-energy HXR source, the Fe xxiii 263.760 Å line at 15 MK shows κ values of typically 4–7. The observed trends in the κ parameter show that we are most likely detecting the properties of the ion population rather than any instrumental effects. We calculate that a non-thermal ion population could exist if locally accelerated on timescales ≤0.1 s. However, observations of net redshifts in the lines also imply the presence of plasma downflows, which could lead to bulk turbulence, with increased non-Gaussianity in cooler regions. Both interpretations have important implications for theories of solar flare particle acceleration.

  10. The soft-photon approximation in infrared-laser-assisted atomic ionization by extreme-ultraviolet attosecond-pulse trains

    NASA Astrophysics Data System (ADS)

    Jiménez Galán, Álvaro; Argenti, Luca; Martín, Fernando

    2013-11-01

    We use the soft-photon approximation, formulated for finite pulses, to investigate the effects of the dressing pulse duration and intensity on simulated attosecond pump-probe experiments employing trains of attosecond extreme-ultraviolet pulses in conjunction with an IR probe pulse. We illustrate the validity of the approximation by comparing the modelled photoelectron distributions for the helium atom, in the photon energy region close to the N = 2 threshold, to the results from the direct solution of the time-dependent Schrödinger equation for two active electrons. Even in the presence of autoionizing states, the model accurately reproduces most of the background features of the ab initio photoelectron spectrum in the 1s channel. A splitting of the photoelectron harmonic signal along the polarization axis, in particular, is attributed to the finite duration of the probe pulse. Furthermore, we study the dependence of the sideband integrated signal on the pump-probe time delay for increasing IR field strengths. Starting at IR intensities of the order of ˜ 1 TW cm-2, overtones in the sideband oscillations due to the exchange of three or more IR photons start to appear. We derive an analytical expression in the frequency-comb limit of the soft-photon model for the amplitude of all the sideband frequency components and show that these amplitudes oscillate as a function of the intensity of the IR field. In particular, we predict that the amplitude of the fundamental component with frequency 2ωIR, on which the rabitt optical reconstruction technique is based, changes sign periodically.

  11. Slow Patchy Extreme-ultraviolet Propagating Fronts Associated with Fast Coronal Magneto-acoustic Waves in Solar Eruptions

    NASA Astrophysics Data System (ADS)

    Guo, Y.; Ding, M. D.; Chen, P. F.

    2015-08-01

    Using the high spatiotemporal resolution extreme ultraviolet (EUV) observations of the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory, we conduct a statistical study of the observational properties of the coronal EUV propagating fronts. We find that it might be a universal phenomenon for two types of fronts to coexist in a large solar eruptive event. It is consistent with the hybrid model of EUV propagating fronts, which predicts that coronal EUV propagating fronts consist of both a fast magneto-acoustic wave and a nonwave component. We find that the morphologies, propagation behaviors, and kinematic features of the two EUV propagating fronts are completely different from each other. The fast magneto-acoustic wave fronts are almost isotropic. They travel continuously from the flaring region across multiple magnetic polarities to global distances. On the other hand, the slow nonwave fronts appear as anisotropic and sequential patches of EUV brightening. Each patch propagates locally in the magnetic domains where the magnetic field lines connect to the bottom boundary and stops at the magnetic domain boundaries. Within each magnetic domain, the velocities of the slow patchy nonwave component are an order of magnitude lower than that of the fast-wave component. However, the patches of the slow EUV propagating front can jump from one magnetic domain to a remote one. The velocities of such a transit between different magnetic domains are about one-third to one-half of those of the fast-wave component. The results show that the velocities of the nonwave component, both within one magnetic domain and between different magnetic domains, are highly nonuniform due to the inhomogeneity of the magnetic field in the lower atmosphere.

  12. Deposition and characterization of B4C/CeO2 multilayers at 6.x nm extreme ultraviolet wavelengths

    NASA Astrophysics Data System (ADS)

    Sertsu, M. G.; Giglia, A.; Brose, S.; Park, D.; Wang, Z. S.; Mayer, J.; Juschkin, L.; Nicolosi, P.

    2016-03-01

    New multilayers of boron carbide/cerium dioxide (B4C/CeO2) combination on silicon (Si) substrate are manufactured to represent reflective-optics candidates for future lithography at 6.x nm wavelength. This is one of only a few attempts to make multilayers of this kind. Combination of several innovative experiments enables detailed study of optical properties, structural properties, and interface profiles of the multilayers in order to open up a room for further optimization of the manufacturing process. The interface profile is visualized by high-angle annular dark-field imaging which provides highly sensitive contrast to atomic number. Synchrotron based at-wavelength extreme ultraviolet (EUV) reflectance measurements near the boron (B) absorption edge allow derivation of optical parameters with high sensitivity to local atom interactions. X-ray reflectivity measurements at Cu-Kalpha (8 keV ) determine the period of multilayers with high in-depth resolution. By combining these measurements and choosing robust nonlinear curve fitting algorithms, accuracy of the results has been significantly improved. It also enables a comprehensive characterization of multilayers. Interface diffusion is determined to be a major cause for the low reflectivity performance. Optical constants of B4C and CeO2 layers are derived in EUV wavelengths. Besides, optical properties and asymmetric thicknesses of inter-diffusion layers (interlayers) in EUV wavelengths near the boron edge are determined. Finally, ideal reflectivity of the B4C/CeO2 combination is calculated by using optical constants derived from the proposed measurements in order to evaluate the potentiality of the design.

  13. The MUSCLES Treasury Survey. II. Intrinsic LYα and Extreme Ultraviolet Spectra of K and M Dwarfs with Exoplanets*

    NASA Astrophysics Data System (ADS)

    Youngblood, Allison; France, Kevin; Parke Loyd, R. O.; Linsky, Jeffrey L.; Redfield, Seth; Schneider, P. Christian; Wood, Brian E.; Brown, Alexander; Froning, Cynthia; Miguel, Yamila; Rugheimer, Sarah; Walkowicz, Lucianne

    2016-06-01

    The ultraviolet (UV) spectral energy distributions (SEDs) of low-mass (K- and M-type) stars play a critical role in the heating and chemistry of exoplanet atmospheres, but are not observationally well-constrained. Direct observations of the intrinsic flux of the Lyα line (the dominant source of UV photons from low-mass stars) are challenging, as interstellar H i absorbs the entire line core for even the closest stars. To address the existing gap in empirical constraints on the UV flux of K and M dwarfs, the MUSCLES Hubble Space Telescope Treasury Survey has obtained UV observations of 11 nearby M and K dwarfs hosting exoplanets. This paper presents the Lyα and extreme-UV spectral reconstructions for the MUSCLES targets. Most targets are optically inactive, but all exhibit significant UV activity. We use a Markov Chain Monte Carlo technique to correct the observed Lyα profiles for interstellar absorption, and we employ empirical relations to compute the extreme-UV SED from the intrinsic Lyα flux in ˜100 Å bins from 100-1170 Å. The reconstructed Lyα profiles have 300 km s-1 broad cores, while >1% of the total intrinsic Lyα flux is measured in extended wings between 300 and 1200 km s-1. The Lyα surface flux positively correlates with the Mg ii surface flux and negatively correlates with the stellar rotation period. Stars with larger Lyα surface flux also tend to have larger surface flux in ions formed at higher temperatures, but these correlations remain statistically insignificant in our sample of 11 stars. We also present H i column density measurements for 10 new sightlines through the local interstellar medium. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the data archive at the Space Telescope Science Institute. STScI is operated by the Association of Universities for Research in Astronomy, Inc. under NASA contract NAS 5-26555.

  14. Extreme ultraviolet reflector

    DOEpatents

    Newnam, Brian E.

    1990-01-01

    A multi-faceted mirror forms a retroreflector for a resonator loop in a free electron laser (FEL) operating in the XUV (.lambda.=10-100 nm). The number of facets is determined by the angle-of-incidence needed to obtain total external reflectance (TER) from the facet surface and the angle through which the FEL beam is to be turned. Angles-of-incidence greater than the angle for TER may be used to increase the area of the beam incident on the surface and reduce energy absorption density. Suitable surface films having TER in the 10-100 nm range may be formed from a variety of materials, including Al, single-crystal Si, Ag, and Rh. One of the facets is formed as an off-axis conic section to collimate the output beam with minimum astigmatism.

  15. Extreme ultraviolet interferometry

    SciTech Connect

    Goldberg, Kenneth A.

    1997-12-01

    EUV lithography is a promising and viable candidate for circuit fabrication with 0.1-micron critical dimension and smaller. In order to achieve diffraction-limited performance, all-reflective multilayer-coated lithographic imaging systems operating near 13-nm wavelength and 0.1 NA have system wavefront tolerances of 0.27 nm, or 0.02 waves RMS. Owing to the highly-sensitive resonant reflective properties of multilayer mirrors and extraordinarily tight tolerances set forth for their fabrication, EUV optical systems require at-wavelength EUV interferometry for final alignment and qualification. This dissertation discusses the development and successful implementation of high-accuracy EUV interferometric techniques. Proof-of-principle experiments with a prototype EUV point-diffraction interferometer for the measurement of Fresnel zoneplate lenses first demonstrated sub-wavelength EUV interferometric capability. These experiments spurred the development of the superior phase-shifting point-diffraction interferometer (PS/PDI), which has been implemented for the testing of an all-reflective lithographic-quality EUV optical system. Both systems rely on pinhole diffraction to produce spherical reference wavefronts in a common-path geometry. Extensive experiments demonstrate EUV wavefront-measuring precision beyond 0.02 waves RMS. EUV imaging experiments provide verification of the high-accuracy of the point-diffraction principle, and demonstrate the utility of the measurements in successfully predicting imaging performance. Complementary to the experimental research, several areas of theoretical investigation related to the novel PS/PDI system are presented. First-principles electromagnetic field simulations of pinhole diffraction are conducted to ascertain the upper limits of measurement accuracy and to guide selection of the pinhole diameter. Investigations of the relative merits of different PS/PDI configurations accompany a general study of the most significant sources of systematic measurement errors. To overcome a variety of experimental difficulties, several new methods in interferogram analysis and phase-retrieval were developed: the Fourier-Transform Method of Phase-Shift Determination, which uses Fourier-domain analysis to improve the accuracy of phase-shifting interferometry; the Fourier-Transform Guided Unwrap Method, which was developed to overcome difficulties associated with a high density of mid-spatial-frequency blemishes and which uses a low-spatial-frequency approximation to the measured wavefront to guide the phase unwrapping in the presence of noise; and, finally, an expedient method of Gram-Schmidt orthogonalization which facilitates polynomial basis transformations in wave-front surface fitting procedures.

  16. Very short-term reactive forecasting of the solar ultraviolet index using an extreme learning machine integrated with the solar zenith angle.

    PubMed

    Deo, Ravinesh C; Downs, Nathan; Parisi, Alfio V; Adamowski, Jan F; Quilty, John M

    2017-05-01

    Exposure to erythemally-effective solar ultraviolet radiation (UVR) that contributes to malignant keratinocyte cancers and associated health-risk is best mitigated through innovative decision-support systems, with global solar UV index (UVI) forecast necessary to inform real-time sun-protection behaviour recommendations. It follows that the UVI forecasting models are useful tools for such decision-making. In this study, a model for computationally-efficient data-driven forecasting of diffuse and global very short-term reactive (VSTR) (10-min lead-time) UVI, enhanced by drawing on the solar zenith angle (θs) data, was developed using an extreme learning machine (ELM) algorithm. An ELM algorithm typically serves to address complex and ill-defined forecasting problems. UV spectroradiometer situated in Toowoomba, Australia measured daily cycles (0500-1700h) of UVI over the austral summer period. After trialling activations functions based on sine, hard limit, logarithmic and tangent sigmoid and triangular and radial basis networks for best results, an optimal ELM architecture utilising logarithmic sigmoid equation in hidden layer, with lagged combinations of θs as the predictor data was developed. ELM's performance was evaluated using statistical metrics: correlation coefficient (r), Willmott's Index (WI), Nash-Sutcliffe efficiency coefficient (ENS), root mean square error (RMSE), and mean absolute error (MAE) between observed and forecasted UVI. Using these metrics, the ELM model's performance was compared to that of existing methods: multivariate adaptive regression spline (MARS), M5 Model Tree, and a semi-empirical (Pro6UV) clear sky model. Based on RMSE and MAE values, the ELM model (0.255, 0.346, respectively) outperformed the MARS (0.310, 0.438) and M5 Model Tree (0.346, 0.466) models. Concurring with these metrics, the Willmott's Index for the ELM, MARS and M5 Model Tree models were 0.966, 0.942 and 0.934, respectively. About 57% of the ELM model's absolute

  17. What can We Learn about Solar Coronal Mass Ejections, Coronal Dimmings, and Extreme-ultraviolet Jets through Spectroscopic Observations?

    NASA Astrophysics Data System (ADS)

    Tian, Hui; McIntosh, Scott W.; Xia, Lidong; He, Jiansen; Wang, Xin

    2012-04-01

    Solar eruptions, particularly coronal mass ejections (CMEs) and extreme-ultraviolet (EUV) jets, have rarely been investigated with spectroscopic observations. We analyze several data sets obtained by the EUV Imaging Spectrometer on board Hinode and find various types of flows during CMEs and jet eruptions. CME-induced dimming regions are found to be characterized by significant blueshift and enhanced line width by using a single Gaussian fit, while a red-blue (RB) asymmetry analysis and an RB-guided double Gaussian fit of the coronal line profiles indicate that these are likely caused by the superposition of a strong background emission component and a relatively weak (~10%), high-speed (~100 km s-1) upflow component. This finding suggests that the outflow velocity in the dimming region is probably of the order of 100 km s-1, not ~20 km s-1 as reported previously. These weak, high-speed outflows may provide a significant amount of mass to refill the corona after the eruption of CMEs, and part of them may experience further acceleration and eventually become solar wind streams that can serve as an additional momentum source of the associated CMEs. Density and temperature diagnostics of the dimming region suggest that dimming is primarily an effect of density decrease rather than temperature change. The mass losses in dimming regions as estimated from different methods are roughly consistent with each other, and they are 20%-60% of the masses of the associated CMEs. With the guide of RB asymmetry analysis, we also find several temperature-dependent outflows (speed increases with temperature) immediately outside the (deepest) dimming region. These outflows may be evaporation flows that are caused by the enhanced thermal conduction or nonthermal electron beams along reconnecting field lines, or induced by the interaction between the opened field lines in the dimming region and the closed loops in the surrounding plage region. In an erupted CME loop and an EUV jet

  18. Chromospheric Evaporation in an M1.8 Flare Observed by the Extreme-ultraviolet Imaging Spectrometer on Hinode

    NASA Astrophysics Data System (ADS)

    Doschek, G. A.; Warren, H. P.; Young, P. R.

    2013-04-01

    We discuss observations of chromospheric evaporation for a complex flare that occurred on 2012 March 9 near 03:30 UT obtained from the Extreme-ultraviolet Imaging Spectrometer (EIS) on board the Hinode spacecraft. This was a multiple event with a strong energy input that reached the M1.8 class when observed by EIS. EIS was in raster mode and fortunately the slit was almost at the exact location of a significant energy input. Also, EIS obtained a full-CCD spectrum of the flare, i.e., the entire CCD was readout so that data were obtained for about the 500 lines identified in the EIS wavelength ranges. Chromospheric evaporation characterized by 150-200 km s-1 upflows was observed in multiple locations in multi-million degree spectral lines of flare ions such as Fe XXII, Fe XXIII, and Fe XXIV, with simultaneous 20-60 km s-1 upflows in million degree coronal lines from ions such as Fe XII-Fe XVI. The behavior of cooler, transition region ions such as O VI, Fe VIII, He II, and Fe X is more complex, but upflows were also observed in Fe VIII and Fe X lines. At a point close to strong energy input in space and time, the flare ions Fe XXII, Fe XXIII, and Fe XXIV reveal an isothermal source with a temperature close to 14 MK and no strong blueshifted components. At this location there is a strong downflow in cooler active region lines from ions such as Fe XIII and Fe XIV, on the order of 200 km s-1. We speculate that this downflow may be evidence of the downward shock produced by reconnection in the current sheet seen in MHD simulations. A sunquake also occurred near this location. Electron densities were obtained from density sensitive lines ratios from Fe XIII and Fe XIV. Atmospheric Imaging Assembly (AIA) observations from the Solar Dynamics Observatory are used with JHelioviewer to obtain a qualitative overview of the flare. However, AIA data are not presented in this paper. In summary, spectroscopic data from EIS are presented that can be used for predictive tests of

  19. A volume-limited ROSAT survey of extreme ultraviolet emission from all nondegenerate stars within 10 parsecs

    NASA Astrophysics Data System (ADS)

    Wood, Brian E.; Brown, Alexander; Linsky, Jeffrey L.; Kellett, Barry J.; Bromage, Gordon E.; Hodgkin, Simon T.; Pye, John P.

    1994-07-01

    We report the results of a volume-limited ROSAT Wide Field Camera (WFC) survey of all nondegenerate stars within 10 pc. Of the 220 known star systems within 10 pc, we find that 41 are positive detections in at least one of the two WFC filter bandpasses (S1 and S2), while we consider another 14 to be marginal detections. We compute X-ray luminosities for the WFC detections using Einstein Imaging Proportional Counter (IPC) data, and these IPC luminosities are discussed along with the WFC luminosities throughout the paper for purposes of comparison. Extreme ultraviolet (EUV) luminosity functions are computed for single stars of different spectral types using both S1 and S2 luminosities, and these luminosity functions are compared with X-ray luminosity functions derived by previous authors using IPC data. We also analyze the S1 and S2 luminosity functions of the binary stars within 10 pc. We find that most stars in binary systems do not emit EUV radiation at levels different from those of single stars, but there may be a few EUV-luminous multiple-star systems which emit excess EUV radiation due to some effect of binarity. In general, the ratio of X-ray luminosity to EUV luminosity increases with increasing coronal emission, suggesting that coronally active stars have higher coronal temperatures. We find that our S1, S2, and IPC luminosities are well correlated with rotational velocity, and we compare activity-rotation relations determined using these different luminosities. Late M stars are found to be significantly less luminous in the EUV than other late-type stars. The most natural explanation for this results is the concept of coronal saturation -- the idea that late-type stars can emit only a limited fraction of their total luminosity in X-ray and EUV radiation, which means stars with very low bolometric luminosities must have relatively low X-ray and EUV luminosities as well. The maximum level of coronal emission from stars with earlier spectral types is studied

  20. A volume-limited ROSAT survey of extreme ultraviolet emission from all nondegenerate stars within 10 parsecs

    NASA Technical Reports Server (NTRS)

    Wood, Brian E.; Brown, Alexander; Linsky, Jeffrey L.; Kellett, Barry J.; Bromage, Gordon E.; Hodgkin, Simon T.; Pye, John P.

    1994-01-01

    We report the results of a volume-limited ROSAT Wide Field Camera (WFC) survey of all nondegenerate stars within 10 pc. Of the 220 known star systems within 10 pc, we find that 41 are positive detections in at least one of the two WFC filter bandpasses (S1 and S2), while we consider another 14 to be marginal detections. We compute X-ray luminosities for the WFC detections using Einstein Imaging Proportional Counter (IPC) data, and these IPC luminosities are discussed along with the WFC luminosities throughout the paper for purposes of comparison. Extreme ultraviolet (EUV) luminosity functions are computed for single stars of different spectral types using both S1 and S2 luminosities, and these luminosity functions are compared with X-ray luminosity functions derived by previous authors using IPC data. We also analyze the S1 and S2 luminosity functions of the binary stars within 10 pc. We find that most stars in binary systems do not emit EUV radiation at levels different from those of single stars, but there may be a few EUV-luminous multiple-star systems which emit excess EUV radiation due to some effect of binarity. In general, the ratio of X-ray luminosity to EUV luminosity increases with increasing coronal emission, suggesting that coronally active stars have higher coronal temperatures. We find that our S1, S2, and IPC luminosities are well correlated with rotational velocity, and we compare activity-rotation relations determined using these different luminosities. Late M stars are found to be significantly less luminous in the EUV than other late-type stars. The most natural explanation for this results is the concept of coronal saturation -- the idea that late-type stars can emit only a limited fraction of their total luminosity in X-ray and EUV radiation, which means stars with very low bolometric luminosities must have relatively low X-ray and EUV luminosities as well. The maximum level of coronal emission from stars with earlier spectral types is studied