Science.gov

Sample records for nm reactions zaselenie

  1. Photochemical reactions of chlorophyll in dehydrated photosystem II: two chlorophyll forms (680 and 700 nm).

    PubMed

    Heber, Ulrich; Shuvalov, Vladimir A

    2005-06-01

    Lichens and phototolerant poikilohydric mosses differ from spinach leaves, fern fronds or photosensitive mosses in that they show strongly decreased Fo chlorophyll fluorescence after drying. This desiccation-induced fluorescence loss is rapidly reversible under rehydration. Fluorescence emission from Photosystem II at 685 nm was decreased more strongly by dehydration than 720 nm emission. Reaction centers of Photosystem II lose activity on dehydration and regain it on hydration. Heating of desiccated lichens increased Fo chlorophyll fluorescence. The activation energy for the reversible part of the temperature-dependent fluorescence increase was 0.045 eV, which corresponds to the energy difference between the 680 and 697 nm absorption bands. In desiccated chlorolichens such as Parmelia sulcata, heating induces the appearance of positive variable fluorescence related to the reversible reduction of QA due to overcoming the energy barrier. This is interpreted to provide information on the mechanism of photoprotection: energy is dissipated by changing Chl680 or P680 into a chlorophyll form, which absorbs at 700 nm and emits light at 720 nm (Chl-720 or P680(700)) with a low quantum yield. Dissipation of light energy in this trap is activated by desiccation. PMID:16049759

  2. Effect of GMB on failure and reaction regime of NM/PMMA-GMB mixtures

    NASA Astrophysics Data System (ADS)

    Gois, Jose; Campos, Jose; Plaksin, Igor

    2001-06-01

    The addition of a small amount of GMB reduces strongly the critical diameter of the NM/PMMA explosive mixture. The same effect is observed on the value of the minimum shock pressure to initiation of detonation. Corner turning research tests were performed to determine the influence of the size and concentration of GMB on the angle of failure and trajectory of the divergent shock wave around the corner. The shape of the traces produced by detonation wave on the cooper witness plate coupled with optical fiber technique were used to evaluate the variation of the reaction regime and the size of cellular structure of the detonation wave. The influence of GMB on extinction and re-initiation of detonation is also evaluated in terms of Dremin's failure theory.

  3. The photodissociation of oxetane at 193 nm as the reverse of the Paterno-Buchi reaction

    SciTech Connect

    Lee, Shih-Huang

    2009-12-14

    We investigated the photodissociation of oxetane (1,3-trimethylene oxide) at 193.3 nm in a molecular-beam apparatus using photofragment-translational spectroscopy and selective photoionization. We measured time-of-flight (TOF) spectra and angular anisotropy parameters {beta}(t) as a function of flight time of products at m/z=26-30 u utilizing photoionization energies from 9.8 to 14.8 eV. The TOF distributions of the products alter greatly with the employed photon energy, whereas their {beta}(t) distributions are insensitive to the photon energy. Dissociation to H{sub 2}CO+C{sub 2}H{sub 4} is the major channel in the title reaction. Three distinct dissociation paths with branching ratios 0.923:0.058:0.019 are responsible for the three features observed in the distribution of kinetic energy released in the channel H{sub 2}CO+C{sub 2}H{sub 4}. The observation of H{sub 2} and H atoms, {approx}1% in branching, indicates that products H{sub 2}CO and C{sub 2}H{sub 4} spontaneously decompose to only a small extent. Most HCO, C{sub 2}H{sub 3}, and C{sub 2}H{sub 2} ions originate from dissociative photoionization of products H{sub 2}CO and C{sub 2}H{sub 4}. Except atomic H and H{sub 2}, the photoproducts have large angular anisotropies, {beta}{>=}-0.8, which reflects rapid dissociation of oxetane following optical excitation at 193.3 nm. The mechanisms of dissociation of oxetane are addressed. Our results confirm the quantum-chemical calculations of Palmer et al. and provide profound insight into the Paterno-Buchi reaction.

  4. Effect of GMB on Failure and Reaction Regime of NM/PMMA-GMB Mixtures

    NASA Astrophysics Data System (ADS)

    Gois, Jose; Campos, Jose; Plaksin, Igor

    2002-07-01

    The effect of the addition of small amounts of glass microballoons (GMB) on heterogeneous explosives has been investigated with the aim of understanding mechanisms that lead to the strong reduction of its critical diameter. However, there is no clear identification of the changes on detonation wave propagation and its structural features. To obtain a better understanding of the contribution of GMB as a particular heterogeneity, the detonation failure and the re-initiation of NM/PMMA-GMB mixtures is studied. Corner turning configuration was performed in order to determine the influence of the GMB concentration and size on failure phenomena by observing the trajectories of the divergent shock waves around the corner. The shape of the printed traces on a copper witness plate, coupled with detonation velocity and front curvature measurements, was used to evaluate the evolution of the detonation reaction regime and its cellular structure. The obtained results of printed flow lines show significant changes of the original pattern of the propagation of the detonation wave. The structural colliding and divergent waves were successful identified and explained.

  5. Collision-induced desorption in 193-nm photoinduced reactions in (O{sub 2}+CO) adlayers on Pt(112)

    SciTech Connect

    Han Song; Ma Yunsheng; Matsushima, Tatsuo

    2005-09-01

    The spatial distribution of desorbing O{sub 2} and CO{sub 2} was examined in 193-nm photoinduced reactions in O{sub 2}+CO adlayers on stepped Pt (112)=[(s)3(111)x(001)]. The O{sub 2} desorption collimated in inclined ways in the plane along the surface trough, confirming the hot-atom collision mechanism. In the presence of CO(a), the product CO{sub 2} desorption also collimated in an inclined way, whereas the inclined O{sub 2} desorption was suppressed. The inclined O{sub 2} and CO{sub 2} desorption is explained by a common collision-induced desorption model. At high O{sub 2} coverage, the CO{sub 2} desorption collimated closely along the (111) terrace normal.

  6. Development of 1480 nm Photothermal High-Speed Real-Time Polymerase Chain Reaction System for Rapid Nucleotide Recognition

    NASA Astrophysics Data System (ADS)

    Terazono, Hideyuki; Hattori, Akihiro; Takei, Hiroyuki; Takeda, Kazuo; Yasuda, Kenji

    2008-06-01

    The polymerase chain reaction (PCR) is a key technology used in genome-based biological analysis; however, requests have been made to shorten the operation time for emergency tests such as medical diagnostics, and countermeasures against bioterrorism. We have developed a novel rapid real-time PCR system using the direct absorption of an IR laser beam by water droplets as the heating device. The advantage of this system is that only the target water droplet was heated photothermally without transmitting any heat to the surroundings, which is important for the production of fast thermal cycle intervals. The system consists of a fluorescent microscope, an oil chamber with a set of water droplets lined up at the bottom, a 1480 nm IR laser unit, which is absorbed by water and can be focused on the droplets on the stage of the microscope, and an image intensifier to quantify the PCR reaction within a water droplet by measuring the change of fluorescent intensity. Using the system, we examined the PCR procedure under the following conditions: initial heating to 95 °C, maintaining this temperature for 10 s, and the suggested here and in similar places throughout 50 cycles of 1 s at 95 °C for denaturation and 3 s at 60 °C for annealing/extension. The temperature increase and decrease between the two temperatures 95 and 60 °C, were within 1 and 0.8 s respectively, i.e., 32 K/s, which is 1.5 times faster than the conventional heat conduction-based system. Rapid PCR amplification was observed successfully by the rise change in the sigmoidal curvature of fluorescent intensity, and the procedure was accomplished within 3.5 min, including the initial heating and complete 50 PCR cycles. The results indicate that the direct absorption-based heating of water droplets photothermally could give us a faster temperature chnage than the conventional heat-conduction-based systems such as Peltier heating/cooling.

  7. Tailoring (n,m) structure of single-walled carbon nanotubes by modifying reaction conditions and the nature of the support of CoMo catalysts.

    PubMed

    Lolli, Giulio; Zhang, Liang; Balzano, Leandro; Sakulchaicharoen, Nataphan; Tan, Yongqiang; Resasco, Daniel E

    2006-02-01

    The (n,m) population distribution of single-walled carbon nanotubes obtained on supported CoMo catalysts has been determined by photoluminescence and optical absorption. It has been found that the (n,m) distribution can be controlled by varying the gaseous feed composition, the reaction temperature, and the type of catalyst support used. When using CO as a feed over CoMo/SiO2 catalysts, increasing the synthesis temperature results in an increase in nanotube diameter, without a change in the chiral angle. By contrast, by changing the support from SiO2 to MgO, nanotubes with similar diameter but different chiral angles are obtained. Finally, keeping the same reaction conditions but varying the composition of the gaseous feed results in different (n,m) distribution. The clearly different distributions obtained when varying catalysts support and/or reaction conditions demonstrate that the (n,m) distribution is a result of differences in the growth kinetics, which in turn depends on the nanotube cap-metal cluster interaction. PMID:16471791

  8. Temperature dependent hole burning of the 684 nm chlorophyll a of the isolated reaction center of Photosystem II: confirmation of the linker model

    NASA Astrophysics Data System (ADS)

    Chang, H.-C.; Small, G. J.; Jankowiak, R.

    1995-05-01

    Currently the nature of the additional chlorophyll a (Chl a) molecules which take the number of Chl a per isolated D1-D2-cyt b 559 complex beyond the value of four for the bacterial reaction center is a subject of much importance and interest. Chang et al. [J. Phys. Chem. 98 (1994) 7725], who studied preparations of this complex with significantly different Chl a contents, concluded that the 684 nm absorbing Chl a contribute to the additional Chl a and proposed that they are of the linker type, serving to shuttle energy from the proximal antenna complex to the reaction center. Implicit in this model is that the 684 nm Chl a communicate with the primary electron donor Chl a (P680) via energy transfer and that the resulting detrapping of the Q y-state of the 684 nm Chl a should depend strongly on temperature. Temperature dependent transient hole spectra are presented that are in complete accord with this prediction. Theoretical calculations on the kinetics and temperature dependence of the hole profile of the 680 nm absorption band are presented and provide convincing support for the linker model. The data are argued to be inconsistent with other models.

  9. 248-nm laser photolysis of CHBr3/O-atom mixtures: kinetic evidence for UV CO(A) chemiluminescence in the reaction of methylidyne radicals with atomic oxygen.

    PubMed

    Vaghjiani, Ghanshyam L

    2005-03-17

    The 4th positive and Cameron band emissions from electronically excited CO have been observed for the first time in 248-nm pulsed laser photolysis of a trace amount of CHBr(3) vapor in an excess of O atoms. O atoms were produced by dissociation of N(2)O (or O(2)) in a cw-microwave discharge cavity in 2.0 Torr of He at 298 K. The CO emission intensity in these bands showed a quadratic dependence on the laser fluence employed. Temporal profiles of the CO(A) and other excited-state products that formed in the photoproduced precursor + O-atom reactions were measured by recording their time-resolved chemiluminescence in discrete vibronic bands. The CO 4th positive transition (A(1)Pi, v' = 0 --> X(1)Sigma(+), v' ' = 2) near 165.7 nm was monitored in this work to deduce the pseudo-first-order decay kinetics of the CO(A) chemiluminescence in the presence of various added substrates (CH(4), NO, N(2)O, H(2), and O(2)). From this, the second-order rate coefficient values were determined for reactions of these substrates with the photoproduced precursors. The measured reactivity trends suggest that the prominent precursors responsible for the CO(A) chemiluminescence are the methylidyne radicals, CH(X(2)Pi) and CH(a(4)Sigma(-)), whose production requires the absorption of at least 2 laser photons by the photolysis mixture. The O-atom reactions with brominated precursors (CBr, CHBr, and CBr(2)), which also form in the photolysis, are shown to play a minor role in the production of the CO(A or a) chemiluminescence. However, the CBr(2) + O-atom reaction was identified as a significant source for the 289.9-nm Br(2) chemiluminescence that was also observed in this work. The 282.2-nm OH and the 336.2-nm NH chemiluminescences were also monitored to deduce the kinetics of CH(X(2)Pi) and CH(a(4)Sigma(-)) reactions when excess O(2) and NO were present. PMID:16838991

  10. Uniform 2 nm gold nanoparticles supported on iron oxides as active catalysts for CO oxidation reaction: Structure-activity relationship

    DOE PAGESBeta

    Guo, Yu; Senanayake, Sanjaya; Gu, Dong; Jin, Zhao; Du, Pei -Pei; Si, Rui; Xu, Wen -Qian; Huang, Yu -Ying; Tao, Jing; Song, Qi -Sheng; et al

    2015-01-12

    Uniform Au nanoparticles (~2 nm) with narrow size-distribution (standard deviation: 0.5–0.6 nm) supported on both hydroxylated (Fe_OH) and dehydrated iron oxide (Fe_O) have been prepared by either deposition-precipitation (DP) or colloidal-deposition (CD) methods. Different structural and textural characterizations were applied to the dried, calcined and used gold-iron oxide samples. The transmission electron microscopy (TEM) and high-resolution TEM (HRTEM) described the high homogeneity in the supported Au nanoparticles. The ex-situ and in-situ X-ray absorption fine structure (XAFS) characterization monitored the electronic and short-range local structure of active gold species. The synchrotron-based in-situ X-ray diffraction (XRD), together with the corresponding temperature-programmed reductionmore » by hydrogen (H₂-TPR), indicated a structural evolution of the iron-oxide supports, correlating to their reducibility. An inverse order of catalytic activity between DP (Au/Fe_OH < Au/Fe_O) and CD (Au/Fe_OH > Au/Fe_O) was observed. Effective gold-support interaction results in a high activity for gold nanoparticles, locally generated by the sintering of dispersed Au atoms on the oxide support in the DP synthesis, while a hydroxylated surface favors the reactivity of externally introduced Au nanoparticles on Fe_OH support for the CD approach. This work reveals why differences in the synthetic protocol translate to differences in the catalytic performance of Au/FeOx catalysts with very similar structural characteristics in CO oxidation.« less

  11. Uniform 2 nm gold nanoparticles supported on iron oxides as active catalysts for CO oxidation reaction: Structure-activity relationship

    SciTech Connect

    Guo, Yu; Senanayake, Sanjaya; Gu, Dong; Jin, Zhao; Du, Pei -Pei; Si, Rui; Xu, Wen -Qian; Huang, Yu -Ying; Tao, Jing; Song, Qi -Sheng; Jia, Chun -Jia; Schueth, Ferdi

    2015-01-12

    Uniform Au nanoparticles (~2 nm) with narrow size-distribution (standard deviation: 0.5–0.6 nm) supported on both hydroxylated (Fe_OH) and dehydrated iron oxide (Fe_O) have been prepared by either deposition-precipitation (DP) or colloidal-deposition (CD) methods. Different structural and textural characterizations were applied to the dried, calcined and used gold-iron oxide samples. The transmission electron microscopy (TEM) and high-resolution TEM (HRTEM) described the high homogeneity in the supported Au nanoparticles. The ex-situ and in-situ X-ray absorption fine structure (XAFS) characterization monitored the electronic and short-range local structure of active gold species. The synchrotron-based in-situ X-ray diffraction (XRD), together with the corresponding temperature-programmed reduction by hydrogen (H₂-TPR), indicated a structural evolution of the iron-oxide supports, correlating to their reducibility. An inverse order of catalytic activity between DP (Au/Fe_OH < Au/Fe_O) and CD (Au/Fe_OH > Au/Fe_O) was observed. Effective gold-support interaction results in a high activity for gold nanoparticles, locally generated by the sintering of dispersed Au atoms on the oxide support in the DP synthesis, while a hydroxylated surface favors the reactivity of externally introduced Au nanoparticles on Fe_OH support for the CD approach. This work reveals why differences in the synthetic protocol translate to differences in the catalytic performance of Au/FeOx catalysts with very similar structural characteristics in CO oxidation.

  12. Odd oxygen formation in the laser irradiation of O2 at 248 nm - Evidence for reactions of O2 in the Herzberg states with ground state O2

    NASA Technical Reports Server (NTRS)

    Shi, Jichun; Barker, John R.

    1992-01-01

    Two O3 formation processes (initiation and autocatalytic) are studied in pure O2 and in O2+N2 and O2+Ar mixtures at pressures between 200 and 1600 torr and at temperatures between 298 and 370 K. Evidence is presented that the initiation process produces O3 through chemical reactions between ground state O2 and excited O2 in the Herzberg states, which are produced by the photoabsorption of O2 at 248 nm. For the autocatalytic process, the results are consistent with the proposal that the O3 formation is accelerated by photodissociating vibrationally excited O2(nu), produced in the photolysis of O3 following its initial formation. It is argued that the O2 Herzberg states and O2(nu) may play important roles in the odd oxygen chemistry in the middle atmosphere. It is estimated that the O2(A3Sigma-u(+))+O2 reaction may yield up to about 6 percent of the total odd oxygen production rate near 50 km.

  13. Optical identification of the long-wavelength (700-1700 nm) electronic excitations of the native reaction centre, Mn4CaO5 cluster and cytochromes of photosystem II in plants and cyanobacteria.

    PubMed

    Morton, Jennifer; Akita, Fusamichi; Nakajima, Yoshiki; Shen, Jian-Ren; Krausz, Elmars

    2015-02-01

    Visible/UV absorption in PS II core complexes is dominated by the chl-a absorptions, which extend to ~700 nm. A broad 700-730 nm PS II core complex absorption in spinach has been assigned to a charge transfer excitation between ChlD1 and ChlD2. Emission from this state, which peaks at 780 nm, has been seen for both plant and cyanobacterial samples. We show that Thermosynechococcus vulcanus PS II core complexes have parallel absorbance in the 700-730 nm region and similar photochemical behaviour to that seen in spinach. This establishes the low energy charge transfer state as intrinsic to the native PS II reaction centre. High-sensitivity MCD measurements made in the 700-1700 nm region reveal additional electronic excitations at ~770 nm and ~1550 nm. The temperature and field dependence of MCD spectra establish that the system peaking near 1550 nm is a heme-to-Fe(III) charge transfer excitation. These transitions have not previously been observed for cyt b559 or cyt c550. The distinctive characteristics of the MCD signals seen at 770 nm allow us to assign absorption in this region to a dz(2)→d(x2-y2) transition of Mn(III) in the Ca-Mn4O5 cluster of the oxygen evolving centre. Current measurements were performed in the S1 state. Detailed analyses of this spectral region, especially in higher S states, promise to provide a new window on models of water oxidation. PMID:25445315

  14. sup 1 (n,. pi. *) photochemistry of acetic acid at 200 nm: Further evidence for an exit channel barrier and reaction selectivity

    SciTech Connect

    Hunnicutt, S.S.; Waits, L.D.; Guest, J.A. )

    1991-01-24

    Acetic acid was photolyzed at 200 nm at low pressure. The nascent OH photofragment was probed by using laser fluorescence excitation to determine its scalar and vector properties. Doppler spectroscopy was used to determine the OH photofragment mean translational energy (E{sub {tau}}(OH) = 10.4 {plus minus} 1.0 kcal mol{sup {minus}1}). Kinematic arguments are presented to demonstrate that acetic acid decomposes via primary C-O single bond fission, with subsequent CH{sub 3}CO decomposition. Nearly the same mean translational energy is imparted to OH for both 200- and 218-nm photolyses, suggesting the presence of a barrier to product formation in the CH{sub 3}COOH {yields} CH{sub 3}CO + OH exit channel. CD{sub 3}COOH was photolyzed at 200 and 218 nm to explore the possibility that an enol intermediate plays a role in the dissociation mechanism.

  15. Fiber-optic epoxy composite cure sensor. I. Dependence of refractive index of an autocatalytic reaction epoxy system at 850 nm on temperature and extent of cure

    NASA Astrophysics Data System (ADS)

    Lam, Kai-Yuen; Afromowitz, Martin A.

    1995-09-01

    We discuss the behavior of the refractive index of a typical epoxy-aromatic diamine system. Near 850 nm the index of refraction is found to be largely controlled by the density of the epoxy. Models are derived to describe its dependence on temperature and extent of cure. Within the range of temperatures studied, the refractive index decreases linearly with increasing temperature. In addition, as the epoxy is cured, the refractive index increases linearly with conversion to the gel point. >From then on, shrinkage in the volume of the epoxy is restricted by local viscosity. Therefore the linear relationship between the refractive index and the extent of cure does not hold beyond the gel point.

  16. Spatially Resolved Mapping of Oxygen Reduction/evolution Reaction on Solid-Oxide Fuel Cell Cathodes with sub-10 nm Resolution

    SciTech Connect

    Kumar, Amit; Leonard, Donovan N; Jesse, Stephen; Ciucci, Francesco; Eliseev, Eugene; Morozovska, A. N.; Biegalski, Michael D; Christen, Hans M; Tselev, Alexander; Mutoro, Eva; Crumlin, Ethan; Morgan, Dane; Shao-Horn, Yang; Borisevich, Albina Y; Kalinin, Sergei

    2013-01-01

    Spatial localization of the oxygen reduction/evolution reactions (ORR/OER) on lanthanum strontium cobaltite (LSCO) surfaces with perovskite and layered perovskite structures is studied on the sub-10 nanometer level. Comparison between Electrochemical Strain Microscopy (ESM) and structural imaging by scanning transmission electron microscopy (STEM) suggest that small-angle grain boundaries act as regions with enhanced electrochemical activity. The ESM activity is compared across a family of LSCO samples, demonstrating excellent agreement with macroscopic behaviors. This study potentially paves the way for deciphering the mechanisms of electrochemical activity of solids on the level of single extended structural defects such as grain boundaries and dislocations.

  17. Soft X-ray spectroscopy studies of adsorption and reaction of CO in the presence of H2 over 6 nm MnO nanoparticles supported on mesoporous Co3O4

    NASA Astrophysics Data System (ADS)

    Ralston, Walter T.; Musselwhite, Nathan; Kennedy, Griffin; An, Kwangjin; Horowitz, Yonatan; Cordones, Amy A.; Rude, Bruce; Ahmed, Musahid; Melaet, Gerome; Alayoglu, Selim

    2016-06-01

    MnO nanoparticles (6 nm) were supported on mesoporous spinel Co3O4 and studied using ambient pressure X-ray photoelectron spectroscopy (APXPS) and in situ X-ray absorption spectroscopy (XAS) during hydrogenation of CO. The nature and evolution of surface adsorbed species as well as the oxidation states of the metal oxide surfaces were evaluated under oxidizing, reducing, and H2 + CO (2:1) reaction atmospheres. From APXPS, MnO nanoparticle surfaces were found to be progressively reduced in H2 atmospheres with increasing temperature. Surface adsorbed CO was found to be formed at the expense of lattice O under H2 + CO reaction conditions. In situ XAS indicated that the dominant oxide species were Co(OH)2, Co (II) oxides, MnO, and Mn3O4 under reaction conditions. In situ XAS also indicated the formation of gas phase CO2, the disappearance of lattice O, and the further reduction of Mn3O4 to MnO upon prolonged reaction in H2 + CO. Mass spectroscopy measurements showed the formation of CO2 and hydrocarbons. The spent catalyst was investigated using scanning transmission X-ray microscopy and (scanning) transmission electron microscopy; the catalyst grains were found to be homogeneous.

  18. Chloroacetone photodissociation at 193 nm and the subsequent dynamics of the CH3C(O)CH2 radical--an intermediate formed in the OH + allene reaction en route to CH3 + ketene.

    PubMed

    Alligood, Bridget W; FitzPatrick, Benjamin L; Szpunar, David E; Butler, Laurie J

    2011-02-01

    We use a combination of crossed laser-molecular beam experiments and velocity map imaging experiments to investigate the primary photofission channels of chloroacetone at 193 nm; we also probe the dissociation dynamics of the nascent CH(3)C(O)CH(2) radicals formed from C-Cl bond fission. In addition to the C-Cl bond fission primary photodissociation channel, the data evidence another photodissociation channel of the precursor, C-C bond fission to produce CH(3)CO and CH(2)Cl. The CH(3)C(O)CH(2) radical formed from C-Cl bond fission is one of the intermediates in the OH + allene reaction en route to CH(3) + ketene. The 193 nm photodissociation laser allows us to produce these CH(3)C(O)CH(2) radicals with enough internal energy to span the dissociation barrier leading to the CH(3) + ketene asymptote. Therefore, some of the vibrationally excited CH(3)C(O)CH(2) radicals undergo subsequent dissociation to CH(3) + ketene products; we are able to measure the velocities of these products using both the imaging and scattering apparatuses. The results rule out the presence of a significant contribution from a C-C bond photofission channel that produces CH(3) and COCH(2)Cl fragments. The CH(3)C(O)CH(2) radicals are formed with a considerable amount of energy partitioned into rotation; we use an impulsive model to explicitly characterize the internal energy distribution. The data are better fit by using the C-Cl bond fission transition state on the S(1) surface of chloroacetone as the geometry at which the impulsive force acts, not the Franck-Condon geometry. Our data suggest that, even under atmospheric conditions, the reaction of OH with allene could produce a small branching to CH(3) + ketene products, rather than solely producing inelastically stabilized adducts. This additional channel offers a different pathway for the OH-initiated oxidation of such unsaturated volatile organic compounds, those containing a C=C=C moiety, than is currently included in atmospheric models

  19. Destruction of microcystins (cyanotoxins) by UV-254 nm-based direct photolysis and advanced oxidation processes (AOPs): influence of variable amino acids on the degradation kinetics and reaction mechanisms.

    PubMed

    He, Xuexiang; de la Cruz, Armah A; Hiskia, Anastasia; Kaloudis, Triantafyllos; O'Shea, Kevin; Dionysiou, Dionysios D

    2015-05-01

    Hepatotoxic microcystins (MCs) are the most frequently detected group of cyanobacterial toxins. This study investigated the degradation of common MC variants in water, MC-LR, MC-RR, MC-YR and MC-LA, by UV-254 nm-based processes, UV only, UV/H2O2, UV/S2O8(2-) and UV/HSO5(-). Limited direct photolysis of MCs was observed, while the addition of an oxidant significantly improved the degradation efficiency with an order of UV/S2O8(2-) > UV/HSO5(-) > UV/H2O2 at the same initial molar concentration of the oxidant. The removal of MC-LR by UV/H2O2 appeared to be faster than another cyanotoxin, cylindrospermopsin, at either the same initial molar concentration or the same initial organic carbon concentration of the toxin. It suggested a faster reaction of MC-LR with hydroxyl radical, which was further supported by the determined second-order rate constant of MCs with hydroxyl radical. Both isomerization and photohydration byproducts were observed in UV only process for all four MCs; while in UV/H2O2, hydroxylation and diene-Adda double bond cleavage byproducts were detected. The presence of a tyrosine in the structure of MC-YR significantly promoted the formation of monohydroxylation byproduct m/z 1061; while the presence of a second arginine in MC-RR led to the elimination of a guanidine group and the absence of double bond cleavage byproducts. It was therefore demonstrated in this study that the variable amino acids in the structure of MCs influenced not only the degradation kinetics but also the preferable reaction mechanisms. PMID:25744186

  20. UV - ALBUQUERQUE NM

    EPA Science Inventory

    Brewer 109 is located in Albuquerque NM, measuring ultraviolet solar radiation. Irradiance and column ozone are derived from this data. Ultraviolet solar radiation is measured with a Brewer Mark IV, single-monochrometer, spectrophotometer manufactured by SCI-TEC Instruments, Inc....

  1. Albuquerque, NM, USA

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Albuquerque, NM (35.0N, 106.5W) is situated on the edge of the Rio Grande River and flood plain which cuts across the image. The reddish brown surface of the Albuquerque Basin is a fault depression filled with ancient alluvial fan and lake bed sediments. On the slopes of the Manzano Mountains to the east of Albuquerque, juniper and other timber of the Cibola National Forest can be seen as contrasting dark tones of vegetation.

  2. 469nm Fiber Laser Source

    SciTech Connect

    Drobshoff, A; Dawson, J W; Pennington, D M; Payne, S A; Beach, R

    2005-01-20

    We have demonstrated 466mW of 469nm light from a frequency doubled continuous wave fiber laser. The system consisted of a 938nm single frequency laser diode master oscillator, which was amplified in two stages to 5 Watts using cladding pumped Nd{sup 3+} fiber amplifiers and then frequency doubled in a single pass through periodically poled KTP. The 3cm long PPKTP crystal was made by Raicol Crystals Ltd. with a period of 5.9 {micro}m and had a phase match temperature of 47 degrees Centigrade. The beam was focused to a 1/e{sup 2} diameter in the crystal of 29 {micro}m. Overall conversion efficiency was 11% and the results agreed well with standard models. Our 938nm fiber amplifier design minimizes amplified spontaneous emission at 1088nm by employing an optimized core to cladding size ratio. This design allows the 3-level transition to operate at high inversion, thus making it competitive with the 1088nm 4-level transition. We have also carefully chosen the fiber coil diameter to help suppress propagation of wavelengths longer than 938 nm. At 2 Watts, the 938nm laser had an M{sup 2} of 1.1 and good polarization (correctable with a quarter and half wave plate to >10:1).

  3. Photoionization of Nitromethane at 355nm and 266nm

    NASA Astrophysics Data System (ADS)

    Martínez, Denhi; Betancourt, Francisco; Poveda, Juan Carlos; Guerrero, Alfonso; Cisneros, Carmen; Álvarez, Ignacio

    2014-05-01

    Nitromethane is one of the high-yield clean liquid fuels, i.e., thanks to the oxygen contained in nitromethane, much less atmospheric oxygen is burned compared to hydrocarbons such as gasoline, making the nitromethane an important prototypical energetic material, the understanding of its chemistry is relevant in other fields such as atmospheric chemistry or biochemistry. In this work we present the study of photoionization dynamics by multiphoton absorption with 355 nm and 266 nm wavelength photons, using time of flight spectrometry in reflectron mode (R-TOF). Some of the observed ion products appear for both wavelength and other only in one of them; both results were compared with preview observations and new ions were detected. This work is supported by CONACYT grant 165410 and DGAPA-UNAM grants IN-107-912 and IN-102-613.

  4. OISL transmitter at 985 nm

    NASA Astrophysics Data System (ADS)

    Larose, Robert; Lauzon, Jocelyn; Mohrdiek, Stefan; Harder, Christoph S.; Changkakoti, Rupak; Park, Peter

    1999-04-01

    For high data rate (greater than 1 Gbps) Optical Inter- Satellite Link (OISL), a compact laser transmitter with high power and good efficiency is required. A trade-off analysis between the technologies such as the mature 840 nm laser diodes, 1064 nm diode-pumped solid state laser and the more recent 1550 nm Erbium Doped Fiber Amplifier (EDFA) is used to find the optical solution. The Si-APDs are preferred for their large detector areas and good noise figures which reduce the tracking requirements and simplify optical design of the receiver. Because of significant amount of power needed to close the link distance up to 7000 km (LEO-LEO), use of 840 nm diodes is limited. In this paper, we present an alternative system based on a system concept denoted as the SLYB (Semiconductor Laser Ytterbium Booster). The SLYB uses a polarization maintaining double-clad ytterbium fiber as a power amplifier. The device houses two semiconductor diodes that are designed to meet telecom reliability: a broad-area 917 nm pump diode and a directly modulated FP laser for signal generation. The output signal is in a linearly polarized state with an extinction ratio of 20 dB. The complete module (15 X 12 X 4.3 cm3) weighs less than 0.9 kg and delivers up to 27 dBm average output power at 985 nm. Designed primarily for direct detection using Si APDs, the transmitter offers a modulation data rate of at least 1.5 Gb/s with a modulation extinction ratio better than 13 dB. Total power consumption is expected to be lower than 8 W by using an uncooled pump laser. Preliminary radiation testing of the fiber indicates output power penalty of 1.5 dB at the end of 10 years in operation. We are presently investigating the fabrication of an improved radiation-hardened Yb-fiber for the final prototype to reduce this penalty. For higher data rate the design can be extended to a Wavelength Division Multiplexing (WDM) scheme adding multiple channels.

  5. Cycloolefin/cyanoacrylate (COCA) copolymers for 193-nm and 157-nm lithography

    NASA Astrophysics Data System (ADS)

    Dammel, Ralph R.; Sakamuri, Raj; Lee, Sang-Ho; Rahman, Dalil; Kudo, Takanori; Romano, Andrew R.; Rhodes, Larry F.; Lipian, John-Henry; Hacker, Cheryl; Barnes, Dennis A.

    2002-07-01

    The copolymerization reaction between methyl cyanoacrylate (MCA) and a variety of cycloolefins (CO) was investigated. Cycololefin/cyanoacrylate (COCA) copolymers were obtained in good yields and with lithographically interesting molecular weights for all cycoolefins studied. Anionic MCA homopolymerization could be largely suppressed using acetic acid. Based on NMR data, the copolymerization may tend to a 1:1 CO:MCA incorporation ratio but further work with better suppression of the anionic component is needed to confirm this. Lithographic tests on copolymers of appropriately substituted norbornenes and MCA showed semi-dense and isolated line performance down to 90 nm.

  6. Comparison of 885 nm pumping and 808 nm pumping in Nd:CNGG laser operating at 1061 nm and 935 nm

    NASA Astrophysics Data System (ADS)

    Shi, Yuxian; Li, Qinan; Zhang, Dongxiang; Feng, Baohua; Zhang, Zhiguo; Zhang, Huaijin; Wang, Jiyang

    2010-07-01

    A Nd:CNGG laser operated at 935 nm and 1061 nm pumped at 885 nm and 808 nm, respectively, is demonstrated. The 885 nm direct pumping scheme shows some advantages over the 808 nm traditional pumping scheme. It includes higher slope efficiency, lower threshold, and better beam quality at high output power. With the direct pumping, the slope efficiency increases by 43% and the threshold decreases by 10% compared with traditional pumping in the Nd:CNGG laser operated at 935 nm. When the Nd:CNGG laser operates at 1061 nm, the direct pumping increases the slope efficiency by 14% with a 20% reduction in the oscillation threshold.

  7. Alternatives to chemical amplification for 193nm lithography

    NASA Astrophysics Data System (ADS)

    Baylav, Burak; Zhao, Meng; Yin, Ran; Xie, Peng; Scholz, Chris; Smith, Bruce; Smith, Thomas; Zimmerman, Paul

    2010-04-01

    Research has been conducted to develop alternatives to chemically amplified 193 nm photoresist materials that will be able to achieve the requirements associated with sub-32 nm device technology. New as well as older photoresist design concepts for non-chemically amplified 193 nm photoresists that have the potential to enable improvements in line edge roughness while maintaining adequate sensitivity, base solubility, and dry etch resistance for high volume manufacturing are being explored. The particular platforms that have been explored in this work include dissolution inhibitor photoresist systems, chain scissioning polymers, and photoresist systems based on polymers incorporating formyloxyphenyl functional groups. In studies of two-component acidic polymer/dissolution inhibitor systems, it was found that compositions using ortho-nitrobenzyl cholate (NBC) as the dissolution inhibitor and poly norbornene hexafluoro alcohol (PNBHFA) as the base resin are capable of printing 90 nm dense line/space patterns upon exposure to a 193 nm laser. Studies of chain scission enhancement in methylmethacrylate copolymers showed that incorporating small amounts of absorptive a-cleavage monomers significantly enhanced sensitivity with an acceptable increase in absorbance at 193 nm. Specifically, it was found that adding 3 mol% of α-methyl styrene (α-MS) reduced the dose to clear of PMMA-based resist from 1400 mJ/cm2 to 420 mJ/cm2. Preliminary data are also presented on a direct photoreactive design concept based on the photo-Fries reaction of formyloxyphenyl functional groups in acrylic copolymers.

  8. Sub-180 nm generation with borate crystal

    NASA Astrophysics Data System (ADS)

    Qu, Chen; Yoshimura, Masashi; Tsunoda, Jun; Kaneda, Yushi; Imade, Mamoru; Sasaki, Takatomo; Mori, Yusuke

    2014-10-01

    We demonstrated a new scheme for the generation of 179 nm vacuum-ultraviolet (VUV) light with an all-solid-state laser system. It was achieved by mixing the deep-ultraviolet (DUV) of 198.8 nm and the infrared (IR) of 1799.9 nm. While CsB3O5 (CBO) did not satisfy the phase-matching at around 180 nm, 179 nm output was generated with LiB3O5 (LBO) for the first time. The phase-matching property of LBO at around 180 nm was also investigated. There was small deviation from theoretical curve in the measurement, which is still considered reasonable.

  9. 147-nm photolysis of disilane

    SciTech Connect

    Perkins, G.G.A.; Lampe, F.W.

    1980-05-21

    The photodecomposition of Si/sub 2/H/sub 6/ at 147 nm results in the formation of H/sub 2/, SiH/sub 4/, Si/sub 3/H/sub 8/, Si/sub 4/H/sub 10/, Si/sub 5/H/sub 12/, and a solid film of amorphous silicon hydride (a-Si:H). Three primary processes are proposed to account for the results, namely, (a) Si/sub 2/H/sub 6/ + h..nu.. ..-->.. SiH/sub 2/ + SiH/sub 3/ + H (phi/sub a/ = 0.61); (b) Si/sub 2/H/sub 6/ + h..nu.. ..-->.. SiH/sub 3/SiH + 2H (phi/sub b/ = 0.18); (c) Si/sub 2/H/sub 6/ + h..nu.. ..-->.. Si/sub 2/H/sub 5/ + H (phi/sub c/ = 0.21). The overall quantum yields depend on the pressure but at 1 Torr partial pressure of Si/sub 2/H/sub 6/ are PHI(-Si/sub 2/H/sub 6/) = 4.3 +- 0.2, PHI(SiH/sub 4/) = 1.2 +- 0.4, PHI(Si/sub 3/H/sub 8/) = 0.91 +- 0.08, PHI(Si/sub 4/H/sub 10/) = 0.62 +- 0.03, PHI(Si,wall) = 2.2. Quantum yields for H/sub 2/ formation were not measured. A mechanism is proposed which is shown to be in accord with the experimental facts.

  10. Cycloolefin-maleic anhydride copolymers for 193-nm resist compositions

    NASA Astrophysics Data System (ADS)

    Rahman, M. D.; Bae, Jun-Bom; Cook, Michelle M.; Durham, Dana L.; Kudo, Takanori; Kim, Woo-Kyu; Padmanaban, Munirathna; Dammel, Ralph R.

    2000-06-01

    Cycloolefin/maleic anhydride systems are a favorable approach to dry etch resistant resists for 193 nm lithography. This paper reports on poly(BNC/HNC/NC/MA) tetrapolymers, from t- butylnorbornene carboxylate (BNC), hydroxyethyl-norbornene carboxylate (HNC), norbornene carboxylic acid (NC) and maleic anhydride (MA). It was found that moisture has to be excluded in the synthesis of these systems if reproducible results are to be obtained. Lithographic evaluation of an optimized, modified polymer has shown linear isolated line resolution down to 100 nm using conventional 193 nm illumination. Possible reactions of the alcohol and anhydride moieties are discussed, and the effect of the anhydride unit on polymer absorbance is discussed using succinnic anhydride as a model compound.

  11. Simultaneous three-wavelength continuous wave laser at 946 nm, 1319 nm and 1064 nm in Nd:YAG

    NASA Astrophysics Data System (ADS)

    Lü, Yanfei; Zhao, Lianshui; Zhai, Pei; Xia, Jing; Fu, Xihong; Li, Shutao

    2013-01-01

    A continuous-wave (cw) diode-end-pumped Nd:YAG laser that generates simultaneous laser at the wavelengths 946 nm, 1319 nm and 1064 nm is demonstrated. The optimum oscillation condition for the simultaneous three-wavelength operation has been derived. Using the separation of the three output couplers, we obtained the maximum output powers of 0.24 W at 946 nm, 1.07 W at 1319 nm and 1.88 W at 1064 nm at the absorbed pump power of 11.2 W. A total output power of 3.19 W for the three-wavelength was achieved at the absorbed pump power of 11.2 W with optical conversion efficiency of 28.5%.

  12. Characteristics of low E a 193-nm chemical amplification resists

    NASA Astrophysics Data System (ADS)

    Ogata, Toshiyuki; Kinoshita, Yohei; Furuya, Sanae; Matsumaru, Shogo; Takahashi, Motoki; Shiono, Daiju; Dazai, Takahiro; Hada, Hideo; Shirai, Masamitsu

    2006-03-01

    Polymers with methyl acetal ester moiety in the side chain as acid labile protecting group were synthesized and their thermal property, plasma stability and chemical amplification (CA) positive-tone resist characteristics were investigated. 2-Admantyloxymethyl (AdOM) groups in the copolymer indicated lower glass transition temperatures and higher thermal decomposition temperatures than those of 2-methyl-2-admantyl (MAd) groups in the copolymer. AdOM polymer film showed smooth surface roughness after Ar plasma exposure compared with MAd polymer film due to the high thermal stability. The activation energies (E a) of these deprotection reactions were calculated from Arrhenius plots of these deprotection reaction rate constants. In the low post exposure bake (PEB) temperature region, the E a of these resists decreased in the order MAd > AdOM. The low E a methyl acetal resists displayed good thermal flow resist characteristics for contact holes printing. In addition, the low E a methyl acetal resist achieved a wide exposure latitude of 8.1 % and depth of focus of 400 nm for printing 80 nm 1:1 dense line pattern using NSR-306C (NA 0.78, 2/3 annular). Furthermore, the 65 nm 1:1 dense lines using ASML XT1400 (NA 0.93, C-Quad) for low E a methyl acetal resist pattern showed no tapered and no footing profiles and small roughness on the lines pattern sidewall was observed.

  13. Simultaneous triple 914 nm, 1084 nm, and 1086 nm operation of a diode-pumped Nd:YVO4 laser

    NASA Astrophysics Data System (ADS)

    Lü, Yanfei; Xia, Jing; Liu, Huilong; Pu, Xiaoyun

    2014-10-01

    We report a diode-pumped continuous-wave (cw) triple-wavelength Nd:YVO4 laser operating at 914, 1084, and 1086 nm. A theoretical analysis has been introduced to determine the threshold conditions for simultaneous triple-wavelength laser. Using a T-shaped cavity, we realized an efficient triple-wavelength operation at 4F3/2→4I9/2 and 4F3/2→4I11/2 transitions for Nd:YVO4 crystal, simultaneously. At an absorbed pump power of 16 W (or 25 W of incident pump power), the maximum output power was 2.3 W, which included 914 nm, 1084 nm, and 1086 nm three wavelengths, and the optical conversion efficiency with respect to the absorbed pump power was 14.4%.

  14. Photodissociation of the hydroxyl radical (OH) at 157 nm

    NASA Technical Reports Server (NTRS)

    Cody, R. J.; Moralejo, C.; Allen, J. E., Jr.

    1991-01-01

    The photodissociation of the OH radical was studied at 157 nm via the detection of the product H atoms with the resonance fluorescence technique. OH radicals were produced in a fast-flow cell from the reaction between H and NO2 and subsequently photodissociated by an excimer laser operating on the F2 emission. The quantum yield for photodissociation of OH was measured to be 1.10 + or - 0.28. The photodissociation cross section was calculated to be 6.6 x 10 to the -18th sq cm (+ or - 25 percent).

  15. O(D-1) production in ozone photolysis near 310 nm

    NASA Technical Reports Server (NTRS)

    Lin, C.; Demore, W. B.

    1973-01-01

    Relative quantum yields of O(D-1)production, phi, in ozone photolysis from 275 nm to 334 nm were determined in the gas phase at 233 K. The O(D-1) was monitored by means of its reaction with isobutane to form isobutyl alcohol. The light source was a high pressure mercury lamp combined with a monochromator, with a bandwidth of 1.6 nm. The results show a constant phi below 300 nm, which is taken as unity on the basis of previous work. There is a very sharp fall-off in phi which is centered at 308 nm. At 313 nm phi is not greater than 0.1.

  16. Sub-10 nm nanopantography

    SciTech Connect

    Tian, Siyuan Donnelly, Vincent M. E-mail: economou@uh.edu; Economou, Demetre J. E-mail: economou@uh.edu; Ruchhoeft, Paul

    2015-11-09

    Nanopantography, a massively parallel nanopatterning method over large areas, was previously shown to be capable of printing 10 nm features in silicon, using an array of 1000 nm-diameter electrostatic lenses, fabricated on the substrate, to focus beamlets of a broad area ion beam on selected regions of the substrate. In the present study, using lens dimensional scaling optimized by computer simulation, and reduction in the ion beam image size and energy dispersion, the resolution of nanopantography was dramatically improved, allowing features as small as 3 nm to be etched into Si.

  17. CMOS downsizing toward sub-10 nm

    NASA Astrophysics Data System (ADS)

    Iwai, Hiroshi

    2004-04-01

    Recently, CMOS downsizing has been accelerated very aggressively in both production and research level, and even transistor operation of a 6 nm gate length p-channel MOSFET was reported in a conference. However, many serious problems are expected for implementing such small-geometry MOSFETs into large scale integrated circuits, and it is still questionable whether we can successfully introduce sub-10 nm CMOS LSIs into the market or not. In this paper, limitation and its possible causes for the downscaling of CMOS towards sub-10 nm are discussed with consideration of past CMOS predictions for the limitation.

  18. Fabrication of 10nm diameter carbon nanopores

    SciTech Connect

    Radenovic, Aleksandra; Trepagnier, Eliane; Csencsits, Roseann; Downing, Kenneth H; Liphardt, Jan

    2008-09-25

    The addition of carbon to samples, during imaging, presents a barrier to accurate TEM analysis, the controlled deposition of hydrocarbons by a focused electron beam can be a useful technique for local nanometer-scale sculpting of material. Here we use hydrocarbon deposition to form nanopores from larger focused ion beam (FIB) holes in silicon nitride membranes. Using this method, we close 100-200nm diameter holes to diameters of 10nm and below, with deposition rates of 0.6nm per minute. I-V characteristics of electrolytic flow through these nanopores agree quantitatively with a one dimensional model at all examined salt concentrations.

  19. Laser Damage Growth in Fused Silica with Simultaneous 351 nm and 1053 nm irradiation

    SciTech Connect

    Norton, M A; Carr, A V; Carr, C W; Donohue, E E; Feit, M D; Hollingsworth, W G; Liao, Z; Negres, R A; Rubenchik, A M; Wegner, P J

    2008-10-24

    Laser-induced growth of optical damage often determines the useful lifetime of an optic in a high power laser system. We have extended our previous work on growth of laser damage in fused silica with simultaneous 351 nm and 1053 nm laser irradiation by measuring the threshold for growth with various ratios of 351 nm and 1053 nm fluence. Previously we reported that when growth occurs, the growth rate is determined by the total fluence. We now find that the threshold for growth is dependent on both the magnitude of the 351 nm fluence as well as the ratio of the 351 nm fluence to the 1053 nm fluence. Furthermore, the data suggests that under certain conditions the 1053 nm fluence does not contribute to the growth.

  20. 308nm excimer laser in dermatology.

    PubMed

    Mehraban, Shadi; Feily, Amir

    2014-01-01

    308nm xenon-chloride excimer laser, a novel mode of phototherapy, is an ultraviolet B radiation system consisting of a noble gas and halide. The aim of this systematic review was to investigate the literature and summarize all the experiments, clinical trials and case reports on 308-nm excimer laser in dermatological disorders. 308-nm excimer laser has currently a verified efficacy in treating skin conditions such as vitiligo, psoriasis, atopic dermatitis, alopecia areata, allergic rhinitis, folliculitis, granuloma annulare, lichen planus, mycosis fungoides, palmoplantar pustulosis, pityriasis alba, CD30+ lympho proliferative disorder, leukoderma, prurigo nodularis, localized scleroderma and genital lichen sclerosus. Although the 308-nm excimer laser appears to act as a promising treatment modality in dermatology, further large-scale studies should be undertaken in order to fully affirm its safety profile considering the potential risk, however minimal, of malignancy, it may impose. PMID:25606333

  1. Optical extension at the 193-nm wavelength

    NASA Astrophysics Data System (ADS)

    Zandbergen, Peter; McCallum, Martin; Amblard, Gilles R.; Domke, Wolf-Dieter; Smith, Bruce W.; Zavyalova, Lena; Petersen, John S.

    1999-07-01

    Lithography at 193nm is the first optical lithography technique that will be introduced for manufacturing of technology levels. where the required dimensions are smaller than the actual wavelength. This paper explores several techniques to extend 193nm to low k1 lithography. Most attention is given to binary mask solution in at 130nm dimensions, where k1 is 0.4. Various strong and Gaussian quadrupole illuminators were designed, manufactured and tested for this application. Strong quadrupoles show that largest DOF improvements. The drawback however, is that these strong quadrupoles are very duty cycle and dimensions specific, resulting in large proximity biases between different duty cycles. Due to their design, Gaussian quadrupoles sample much wider frequency ranges, resulting in less duty cycles specific DOF improvements and less proximity basis. At sub-130nm dimensions, strong phase shift masks provide significant latitude improvements, when compared to binary masks with quadrupole illumination. However, differences in dose to size for different duty cycles were up to 25 percent. For definition of contact holes, linewidth biasing through silylation, a key feature of the CARL bi-layer resist approach, demonstrated significant DOF latitude improvements compared to SLR at 140nm and 160nm contact holes.

  2. The Double-ended 750 nm and 532 nm Laser Output from PPLN-FWM

    NASA Astrophysics Data System (ADS)

    Wang, Tao; Li, Yu-Xiang; Yao, Jian-Quan; Guo, Ling; Wang, Zhuo; Han, Sha-Sha; Zhang, Cui-Ying; Zhong, Kai

    2013-06-01

    We investigate 750 nm and 532 nm dual-wavelength laser for applications in the internet of things. A kind of optical maser is developed, in which the semiconductor module outputs the 808 nm pump light and then it goes into a double-clad Nd3+ :YAG monocrystal optical fiber through the intermediate coupler and forms a 1064 nm laser. The laser outputs come from both left and right terminals. In the right branch, the laser goes into the right cycle polarization LinNbO3 (PPLN) crystal through the right coupler, produces the optical parametric oscillation and forms the signal light λ1 (1500 nm), the idle frequency light λ2 (3660.55 nm), and the second-harmonic of the signal light λ3 (750 nm). These three kinds of light and the pump light λ4 together form the frequency matching and the quasi-phase matching, then the four-wave mixing occurs to create the high-gain light at wavelength 750 nm. Meanwhile, in the left branch, the laser goes into the left PPLN crystal through the left coupler, engenders frequency doubling and forms the light at wavelength 532 nm. That is to say, the optical maser provides 750 nm and 532 nm dual-wavelength laser outputting from two terminals, which is workable.

  3. 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.

  4. Chromosomes without a 30-nm chromatin fiber

    PubMed Central

    Joti, Yasumasa; Hikima, Takaaki; Nishino, Yoshinori; Kamada, Fukumi; Hihara, Saera; Takata, Hideaki; Ishikawa, Tetsuya; Maeshima, Kazuhiro

    2012-01-01

    How is a long strand of genomic DNA packaged into a mitotic chromosome or nucleus? The nucleosome fiber (beads-on-a-string), in which DNA is wrapped around core histones, has long been assumed to be folded into a 30-nm chromatin fiber, and a further helically folded larger fiber. However, when frozen hydrated human mitotic cells were observed using cryoelectron microscopy, no higher-order structures that included 30-nm chromatin fibers were found. To investigate the bulk structure of mitotic chromosomes further, we performed small-angle X-ray scattering (SAXS), which can detect periodic structures in noncrystalline materials in solution. The results were striking: no structural feature larger than 11 nm was detected, even at a chromosome-diameter scale (~1 μm). We also found a similar scattering pattern in interphase nuclei of HeLa cells in the range up to ~275 nm. Our findings suggest a common structural feature in interphase and mitotic chromatins: compact and irregular folding of nucleosome fibers occurs without a 30-nm chromatin structure. PMID:22825571

  5. 810nm, 980nm, 1470nm and 1950nm diode laser comparison: a preliminary "ex vivo" study on oral soft tissues

    NASA Astrophysics Data System (ADS)

    Fornaini, Carlo; Merigo, Elisabetta; Sozzi, Michele; Selleri, Stefano; Vescovi, Paolo; Cucinotta, Annamaria

    2015-02-01

    The introduction of diode lasers in dentistry has several advantages, mainly consisting on the reduced size, reduced cost and possibility to beam delivering by optical fibers. At the moment the two diode wavelengths normally utilized in the dental field are 810 and 980 nm for soft tissues treatments. The aim of this study was to compare the efficacy of four different diode wavelengths: 810, 980, 1470 and 1950 nm diode laser for the ablation of soft tissues. Several samples of veal tongue were exposed to the four different wavelengths, at different fluences. The internal temperature of the soft tissues, in the area close to the beam, was monitored with thermocouple during the experiment. The excision quality of the exposed samples have been characterized by means of an optical microscope. Tissue damages and the cut regularity have been evaluated on the base of established criteria. The lowest thermal increase was recorded for 1950 nm laser. Best quality and speed of incision were obtained by the same wavelength. By evaluating epithelial, stromal and vascular damages for all the used wavelengths, the best result, in terms of "tissue respect", have been obtained for 1470 and 1950 nm exposures. From the obtained results 1470 and 1950 nm diode laser showed to be the best performer wavelengths among these used in this "ex vivo" study, probably due to their greatest affinity to water.

  6. Radiation Failures in Intel 14nm Microprocessors

    NASA Technical Reports Server (NTRS)

    Bossev, Dobrin P.; Duncan, Adam R.; Gadlage, Matthew J.; Roach, Austin H.; Kay, Matthew J.; Szabo, Carl; Berger, Tammy J.; York, Darin A.; Williams, Aaron; LaBel, K.; Ingalls, James D.

    2016-01-01

    In this study the 14 nm Intel Broadwell 5th generation core series 5005U-i3 and 5200U-i5 was mounted on Dell Inspiron laptops, MSI Cubi and Gigabyte Brix barebones and tested with Windows 8 and CentOS7 at idle. Heavy-ion-induced hard- and catastrophic failures do not appear to be related to the Intel 14nm Tri-Gate FinFET process. They originate from a small (9 m 140 m) area on the 32nm planar PCH die (not the CPU) as initially speculated. The hard failures seem to be due to a SEE but the exact physical mechanism has yet to be identified. Some possibilities include latch-ups, charge ion trapping or implantation, ion channels, or a combination of those (in biased conditions). The mechanism of the catastrophic failures seems related to the presence of electric power (1.05V core voltage). The 1064 nm laser mimics ionization radiation and induces soft- and hard failures as a direct result of electron-hole pair production, not heat. The 14nm FinFET processes continue to look promising for space radiation environments.

  7. Diode laser (980nm) cartilage reshaping

    NASA Astrophysics Data System (ADS)

    El Kharbotly, A.; El Tayeb, T.; Mostafa, Y.; Hesham, I.

    2011-03-01

    Loss of facial or ear cartilage due to trauma or surgery is a major challenge to the otolaryngologists and plastic surgeons as the complicated geometric contours are difficult to be animated. Diode laser (980 nm) has been proven effective in reshaping and maintaining the new geometric shape achieved by laser. This study focused on determining the optimum laser parameters needed for cartilage reshaping with a controlled water cooling system. Harvested animal cartilages were angulated with different degrees and irradiated with different diode laser powers (980nm, 4x8mm spot size). The cartilage specimens were maintained in a deformation angle for two hours after irradiation then released for another two hours. They were serially measured and photographed. High-power Diode laser irradiation with water cooling is a cheep and effective method for reshaping the cartilage needed for reconstruction of difficult situations in otorhinolaryngologic surgery. Key words: cartilage,diode laser (980nm), reshaping.

  8. Super ACO FEL oscillation at 300 nm

    NASA Astrophysics Data System (ADS)

    Nutarelli, D.; Garzella, D.; Renault, E.; Nahon, L.; Couprie, M. E.

    2000-05-01

    Some recent improvements, involving both the optical cavity mirrors and the positron beam dynamics in the storage ring, have allowed us to achieve a laser oscillation at 300 nm on the Super ACO Storage Ring FEL. The Super ACO storage ring is operated at 800 MeV which is the nominal energy for the usual synchrotron radiation users, and the highest energy for a storage ring FEL. The lasing at 300 nm could be kept during 2 h per injection, with a stored current ranging between 30 and 60 mA. The FEL characteristics are presented here. The longitudinal stability and the FEL optics behaviour are also discussed.

  9. 1550-nm wavelength-tunable HCG VCSELs

    NASA Astrophysics Data System (ADS)

    Chase, Christopher; Rao, Yi; Huang, Michael; Chang-Hasnain, Connie

    2014-02-01

    We demonstrate wavelength-tunable VCSELs using high contrast gratings (HCGs) as the top output mirror on VCSELs, operating at 1550 nm. Tunable HCG VCSELs with a ~25 nm mechanical tuning range as well as VCSELs with 2 mW output power were realized. Error-free operation of an optical link using directly-modulated tunable HCG VCSELs transmitting at 1.25 Gbps over 18 channels spaced by 100 GHz and transmitted over 20 km of single mode fiber is demonstrated, showing the suitability of the HCG tunable VCSEL as a low cost source for WDM communications systems.

  10. Comparative study of Nd:KGW lasers pumped at 808 nm and 877 nm

    NASA Astrophysics Data System (ADS)

    Huang, Ke; Ge, Wen-Qi; Zhao, Tian-Zhuo; He, Jian-Guo; Feng, Chen-Yong; Fan, Zhong-Wei

    2015-10-01

    The laser performance and thermal analysis of Nd:KGW laser continuously pumped by 808 nm and 877 nm are comparatively investigated. Output power of 670 mW and 1587 mW, with nearly TEM00 mode, are achieved respectively at 808 nm pump and 877 nm pump. Meanwhile, a high-power passively Q-switched Nd:KGW/Cr4+:YAG laser pumped at 877 nm is demonstrated. An average output power of 1495 mW is obtained at pump power of 5.22 W while the laser is operating at repetition of 53.17 kHz. We demonstrate that 877 nm diode laser is a more potential pump source for Nd:KGW lasers.

  11. Radiation Tolerance of 65nm CMOS Transistors

    DOE PAGESBeta

    Krohn, M.; Bentele, B.; Christian, D. C.; Cumalat, J. P.; Deptuch, G.; Fahim, F.; Hoff, J.; Shenai, A.; Wagner, S. R.

    2015-12-11

    We report on the effects of ionizing radiation on 65 nm CMOS transistors held at approximately -20°C during irradiation. The pattern of damage observed after a total dose of 1 Grad is similar to damage reported in room temperature exposures, but we observe less damage than was observed at room temperature.

  12. Negative-tone 193-nm resists

    NASA Astrophysics Data System (ADS)

    Cho, Sungseo; Vander Heyden, Anthony; Byers, Jeff D.; Willson, C. Grant

    2000-06-01

    A great deal of progress has been made in the design of single layer positive tone resists for 193 nm lithography. Commercial samples of such materials are now available from many vendors. The patterning of certain levels of devices profits from the use of negative tone resists. There have been several reports of work directed toward the design of negative tones resists for 193 nm exposure but, none have performed as well as the positive tone systems. Polymers with alicyclic structures in the backbone have emerged as excellent platforms from which to design positive tone resists for 193 nm exposure. We now report the adaptation of this class of polymers to the design of high performance negative tone 193 nm resists. New systems have been prepared that are based on a polarity switch mechanism for modulation of the dissolution rate. The systems are based on a polar, alicyclic polymer backbone that includes a monomer bearing a glycol pendant group that undergoes the acid catalyzed pinacol rearrangement upon exposure and bake to produce the corresponding less polar ketone. This monomer was copolymerized with maleic anhydride and a norbornene bearing a bis-trifluoromethylcarbinol. The rearrangement of the copolymer was monitored by FT-IR as a function of temperature. The synthesis of the norbornene monomers will be presented together with characterization of copolymers of these monomers with maleic anhydride. The lithographic performance of the new resist system will also be presented.

  13. White Sands, Carrizozo Lava Beds, NM

    NASA Technical Reports Server (NTRS)

    1973-01-01

    A truly remarkable view of White Sands and the nearby Carrizozo Lava Beds in southeast NM (33.5N, 106.5W). White Sands, site of the WW II atomic bomb development and testing facility and later post war nuclear weapons testing that can still be seen in the cleared circular patterns on the ground.

  14. Drug Reactions

    MedlinePlus

    Most of the time, medicines make our lives better. They reduce aches and pains, fight infections, and control problems such as high blood pressure or diabetes. But medicines can also cause unwanted reactions. One problem is ...

  15. VizieR Online Data Catalog: Thorium spectrum from 250nm to 5500nm (Redman+, 2014)

    NASA Astrophysics Data System (ADS)

    Redman, S. L.; Nave, G.; Sansonetti, C. J.

    2014-04-01

    We observed the spectrum of a commercial sealed Th/Ar HCL running at 25mA for almost 15hr starting on 2011 November 2. The region of observation was limited to between 8500/cm and 28000/cm (360nm and 1200nm) by the sensitivity of the silicon photodiode detector. (5 data files).

  16. Laser damage database at 1064 nm

    SciTech Connect

    Rainer, F.; Gonzales, R.P.; Morgan, A.J.

    1990-03-01

    In conjunction with our diversification of laser damage testing capabilities, we have expanded upon a database of threshold measurements and parameter variations at 1064 nm. This includes all tests at low pulse-repetition frequencies (PRF) ranging from single shots to 120 Hz. These tests were conducted on the Reptile laser facility since 1987 and the Variable Pulse Laser (VPL) facility since 1988. Pulse durations ranged from 1 to 16 ns. 10 refs., 14 figs.

  17. Sunlight induced 685 nm fluorescence imagery

    NASA Technical Reports Server (NTRS)

    Kim, Hongsuk H.; Van Der Piepen, Heinz

    1986-01-01

    The capability of a new fluorescence method is evaluated using data from an aircraft fluorescence experiment conducted on the Elbe River on August 10-14, 1981. The technique measures chlorophyll concentrations by monitoring sunlight-induced fluorescence at 685 nm. Upwelling radiance spectra and vertical profiles of upwelling radiances are presented and analyzed. The image-processing algorithm used to retrieve fluorescence signals from raw data is described.

  18. Radiation Status of Sub-65 nm Electronics

    NASA Technical Reports Server (NTRS)

    Pellish, Jonathan A.

    2011-01-01

    Ultra-scaled complementary metal oxide semiconductor (CMOS) includes commercial foundry capabilities at and below the 65 nm technology node Radiation evaluations take place using standard products and test characterization vehicles (memories, logic/latch chains, etc.) NEPP focus is two-fold: (1) Conduct early radiation evaluations to ascertain viability for future NASA missions (i.e. leverage commercial technology development). (2) Uncover gaps in current testing methodologies and mechanism comprehension -- early risk mitigation.

  19. Binary 193nm photomasks aging phenomenon study

    NASA Astrophysics Data System (ADS)

    Dufaye, Félix; Sartelli, Luca; Pogliani, Carlo; Gough, Stuart; Sundermann, Frank; Miyashita, Hiroyuki; Hidenori, Yoshioka; Charras, Nathalie; Brochard, Christophe; Thivolle, Nicolas

    2011-05-01

    193nm binary photomasks are still used in the semiconductor industry for the lithography of some critical layers for the nodes 90nm and 65nm, with high volumes and over long period. These 193nm binary masks seem to be well-known but recent studies have shown surprising degrading effects, like Electric Field induced chromium Migration (EFM) [1] or chromium migration [2] [3] . Phase shift Masks (PSM) or Opaque MoSi On Glass (OMOG) might not be concerned by these effects [4] [6] under certain conditions. In this paper, we will focus our study on two layers gate and metal lines. We will detail the effects of mask aging, with SEM top view pictures revealing a degraded chromium edge profile and TEM chemical analyses demonstrating the growth of a chromium oxide on the sidewall. SEMCD measurements after volume production indicated a modified CD with respect to initial CD data after manufacture. A regression analysis of these CD measurements shows a radial effect, a die effect and an isolated-dense effect. Mask cleaning effectiveness has also been investigated, with sulphate or ozone cleans, to recover the mask quality in terms of CD. In complement, wafer intrafield CD measurements have been performed on the most sensitive structure to monitor the evolution of the aging effect on mask CD uniformity. Mask CD drift have been correlated with exposure dose drift and isolated-dense bias CD drift on wafers. In the end, we will try to propose a physical explanation of this aging phenomenon and a solution to prevent from it occurring.

  20. AIMS mask qualification for 32nm node

    NASA Astrophysics Data System (ADS)

    Richter, Rigo; Thaler, Thomas; Seitz, Holger; Stroessner, Ulrich; Scheruebl, Thomas

    2009-10-01

    Moving forward to 32nm node and below optical lithography using 193nm is faced with complex requirements to be solved. Mask makers are forced to address both Double Patterning Techniques and Computational Lithography approaches such as Source Mask Optimizations and Inverse Lithography. Additionally, lithography at low k1 values increases the challenges for mask repair as well as for repair verification and review by AIMSTM. Higher CD repeatability, more flexibility in the illumination settings as well as significantly improved image performance must be added when developing the next generation mask qualification equipment. This paper reports latest measurement results verifying the appropriateness of the latest member of AIMSTM measurement tools - the AIMSTM 32-193i. We analyze CD repeatability measurements on lines and spaces pattern. The influence of the improved optical performance and newly introduced interferometer stage will be verified. This paper highlights both the new Double Patterning functionality emulating double patterning processes and the influence of its critical parameters such as overlay errors and resist impact. Beneficial advanced illumination schemes emulating scanner illumination document the AIMSTM 32-193i to meet mask maker community's requirements for the 32nm node.

  1. 635nm diode laser biostimulation on cutaneous wounds

    NASA Astrophysics Data System (ADS)

    Solmaz, Hakan; Gülsoy, Murat; Ülgen, Yekta

    2014-05-01

    Biostimulation is still a controversial subject in wound healing studies. The effect of laser depends of not only laser parameters applied but also the physiological state of the target tissue. The aim of this project is to investigate the biostimulation effects of 635nm laser irradiation on the healing processes of cutaneous wounds by means of morphological and histological examinations. 3-4 months old male Wistar Albino rats weighing 330 to 350 gr were used throughout this study. Low-level laser therapy was applied through local irradiation of red light on open skin excision wounds of 5mm in diameter prepared via punch biopsy. Each animal had three identical wounds on their right dorsal part, at which two of them were irradiated with continuous diode laser of 635nm in wavelength, 30mW of power output and two different energy densities of 1 J/cm2 and 3 J/cm2. The third wound was kept as control group and had no irradiation. In order to find out the biostimulation consequences during each step of wound healing, which are inflammation, proliferation and remodeling, wound tissues removed at days 3, 7, 10 and 14 following the laser irradiation are morphologically examined and than prepared for histological examination. Fragments of skin including the margin and neighboring healthy tissue were embedded in paraffin and 6 to 9 um thick sections cut are stained with hematoxylin and eosin. Histological examinations show that 635nm laser irradiation accelerated the healing process of cutaneous wounds while considering the changes of tissue morphology, inflammatory reaction, proliferation of newly formed fibroblasts and formation and deposition of collagen fibers. The data obtained gives rise to examine the effects of two distinct power densities of low-level laser irradiation and compare both with the non-treatment groups at different stages of healing process.

  2. Nanocomposite liquids for 193 nm immersion lithography: a progress report

    NASA Astrophysics Data System (ADS)

    Chumanov, George; Evanoff, David D., Jr.; Luzinov, Igor; Klep, Viktor; Zdryko, Bogdan; Conley, Will; Zimmerman, Paul

    2005-05-01

    Immersion lithography is a new promising approach capable of further increasing the resolution of semiconductor devices. This technology requires the development of new immersion media that satisfy the following conditions: the media should have high refractive index, be transparent and photochemically stable in DUV spectral range. They should also be inert towards photoresists and optics and be liquid to permit rapid scanning. Here we propose and explore a novel strategy in which high refractive index medium is made of small solid particles suspended in liquid phases (nanocomposite liquids). The dielectric particles have high refractive index and the refractive index of nanocomposite liquids becomes volume weighted average between refractive indices of nanoparticles and the liquid phase. We investigate aluminum oxide (alumina) nanoparticles suspended in water. Alumina is known to have high (1.95) refractive index and low absorption coefficient at 193 nm. Alumina nanoparticles were prepared by chemical methods followed by removal of organic molecules left after hydrolysis reactions. Measurements of optical and reological properties of the nanocomposite liquid demonstrated potential advantage of this approach for 193 nm immersion lithography.

  3. Sub-50nm extreme ultraviolet holographic imaging

    NASA Astrophysics Data System (ADS)

    Wachulak, P. W.; Marconi, M. C.; Bartels, R. A.; Menoni, C. S.; Rocca, J. J.

    2009-05-01

    Imaging tools for nanoscicence involving sub-100-nm scale objects have been dominated by atomic force microscopy (AFM), scanning tunneling microscopy (STM), and electron microscopy (SEM, TEM). These imaging techniques have contributed substantially to the development of nanoscience, providing a very powerful diagnostic tool capable of obtaining images with atomic resolution or as a subsidiary mechanism to arrange or modify surfaces also at the atomic scale [1,2]. However, some important problems have persisted traditional nanoscale imaging techniques. For example when scanning a nanometer size object that is not attached rigidly to a surface the interaction with the tip significantly perturbs the specimen degrading or eventually precluding the image acquisition. Electron microscopy often requires surface preparation, consisting of metallization of the sample to avoid surface charging. Additionally the metallization of the sample may alter its characteristics and also limits the resolution. In both cases, if the sample is large (millimeters in size) due to the limited field of view, the image obtained with these conventional methods is only representative of a very small portion of the object. Wavelength-limited holographic imaging using carbon nanotubes as the test object with a table-top extreme ultraviolet (EUV) laser operating at 46.9 nm will be discussed. The resolution achieved in this imaging is evaluated with a rigorous correlation image analysis and confirmed with the conventional knife-edge test. The nano-holography presented requires no optics or critical beam alignment; thus the hologram recording scheme is very simple and does not need special sample preparation. In holography, image contrast requires absorption to provide scattering by the illuminating beam. The EUV laser wavelength employed in this experiment (46.9nm) is advantageous because carbon based materials typically exhibit very small attenuation lengths, around 25 nm. The high absorption of

  4. Synthesis and bioconjugation of 2 and 3 nm-diameter gold nanoparticles.

    PubMed

    Ackerson, Christopher J; Jadzinsky, Pablo D; Sexton, Jonathan Z; Bushnell, David A; Kornberg, Roger D

    2010-02-17

    By adjustment of solvent conditions for synthesis, virtually monodisperse 4-mercaptobenzoic acid (p-MBA) monolayer-protected gold nanoparticles, 2 and 3 nm in diameter, were obtained. Large single crystals of the 2 nm particles could be grown from the reaction mixture. Uniformity was also demonstrated by the formation of two-dimensional arrays and by quantitative high-angle annular dark-field scanning transmission electron microscopy. The 2 and 3 nm particles were spontaneously reactive for conjugation with proteins and DNA, and further reaction could be prevented by repassivation with glutathione. Conjugates with antibody Fc fragment could be used to identify TAP-tagged proteins of interest in electron micrographs, through the binding of a pair of particles to the pair of protein A domains in the TAP tag. PMID:20099843

  5. Drug Reactions

    MedlinePlus

    ... using any of these products. Some types of food may also cause adverse drug reactions. For example, grapefruit and grapefruit juice, as well as alcohol and caffeine, may affect how drugs work. Every time your doctor ... interactions with any foods or beverages. What about medicines I've used ...

  6. Scaling of laser-induced contamination growth at 266nm and 355nm

    NASA Astrophysics Data System (ADS)

    Ließmann, M.; Jensen, L.; Balasa, I.; Hunnekuhl, M.; Büttner, A.; Weßels, P.; Neumann, J.; Ristau, D.

    2015-11-01

    The growth of laser-induced contamination (LIC) on optical components in extraterrestrial missions is a known issue especially for the UV spectral region. The Laser Zentrum Hannover e.V. is responsible for the development of a pulsed laser-system operating at a wavelength of 266 nm for the ExoMars mission and for the qualification of used optics and materials regarding LIC. In this context, toluene was utilized which is an often used model contaminant in LIC studies. Test cycles based on the application of the two UV wavelengths 355 nm and 266 nm on fused silica substrates and ARcoated optics are conducted and the observed contamination effects are compared. This scaling allows for a rough estimate of the destructive influence of LIC on space optics degradation at 266 nm. Further tests will be performed with materials integrated into the ExoMars-laser-head under near-operation environmental conditions.

  7. An 885-nm Direct Pumped Nd:CNGG 1061 nm Q-Switched Laser

    NASA Astrophysics Data System (ADS)

    Li, Qi-Nan; Zhang, Tao; Feng, Bao-Hua; Zhang, Zhi-Guo; Zhang, Huai-Jin; Wang, Ji-Yang

    2014-07-01

    The 885 nm direct pumping method, directly into the 4F3/2 emitting level of Nd3+ ion, is used to a Nd:CNGG crystal to product passive Q-switched 1061 nm laser pulses, for the first time to the best of our knowledge. A maximum average output power of 1.16 W for 1061 nm Q-switched pulses and a repetition rate of 12.54 kHz are obtained. The pulse width is measured to be 24 ns and the peak power is 3.843 kW. A high-quality fundamental transverse mode can be observed owing to the reduction of the thermal effect for Nd:CNGG crystal by 885 nm direct pumping.

  8. 1064 nm Nd:YAG laser intracavity pumped at 946 nm and sum-frequency mixing for an emission at 501 nm

    NASA Astrophysics Data System (ADS)

    Lü, Y. F.; Zhang, X. H.; Xia, J.; Jin, G. Y.; Wang, J. G.; Yin, X. D.; Zhang, A. F.

    2010-05-01

    We present for the first time a Nd:YAG laser emitting at 1064 nm intracavity pumped by a 946 nm diode-pumped Nd:YAG laser. A 809 nm laser diode is used to pump the first Nd:YAG crystal emitting at 946 nm, and the second Nd:YAG laser emitting at 1064 nm intracavity pumped at 946 nm. Intracavity sum-frequency mixing at 946 and 1064 nm was then realized in a LBO crystal to reach the cyan range. We obtained a continuous-wave output power of 485 mW at 501 nm with a pump laser diode emitting 25.4 W at 809 nm.

  9. Deep ultraviolet (254 nm) focal plane array

    NASA Astrophysics Data System (ADS)

    Cicek, Erdem; Vashaei, Zahra; McClintock, Ryan; Razeghi, Manijeh

    2011-10-01

    We report the synthesis, fabrication and testing of a 320 × 256 focal plane array (FPA) of back-illuminated, solarblind, p-i-n, AlxGa1-xN-based detectors, fully realized within our research laboratory. We implemented a novel pulsed atomic layer deposition technique for the metalorganic chemical vapor deposition (MOCVD) growth of crackfree, thick, and high Al composition AlxGa1-xN layers. Following the growth, the wafer was processed into a 320 × 256 array of 25 μm × 25 μm pixels on a 30 μm pixel-pitch and surrounding mini-arrays. A diagnostic mini-array was hybridized to a silicon fan-out chip to allow the study of electrical and optical characteristics of discrete pixels of the FPA. At a reverse bias of 1 V, an average photodetector exhibited a low dark current density of 1.12×10-8 A/cm2. Solar-blind operation is observed throughout the array with peak detection occurring at wavelengths of 256 nm and lower and falling off three orders of magnitude by 285 nm. After indium bump deposition and dicing, the FPA is hybridized to a matching ISC 9809 readout integrated circuit (ROIC). By developing a novel masking technology, we significantly reduced the visible response of the ROIC and thus the need for external filtering to achieve solar- and visible-blind operation is eliminated. This allowed the FPA to achieve high external quantum efficiency (EQE): at 254 nm, average pixels showed unbiased peak responsivity of 75 mA/W, which corresponds to an EQE of ~37%. Finally, the uniformity of the FPA and imaging properties are investigated.

  10. Fluorinated dissolution inhibitors for 157-nm lithography

    NASA Astrophysics Data System (ADS)

    Hamad, Alyssandrea H.; Bae, Young C.; Liu, Xiang-Qian; Ober, Christopher K.; Houlihan, Francis M.; Dabbagh, Gary; Novembre, Anthony E.

    2002-07-01

    Fluorinated dissolution inhibitors (DIs) for 157 nm lithography were designed and synthesized as part of an ongoing study on the structure/property relationships of photoresist additives. The problem of volatilization of small DI candidates was observed from matrices such as poly(methyl methacrylate) (PMMA) and poly(hexafluorohydroxy-isopropyl styrene) (PHFHIPS) during post-apply bake cycles using Fourier Transform Infrared Spectroscopy (FT-IR). To avoid this problem, low volatility fluorinated inhibitors were designed and synthesized. Three fluorinated DIs, perfluorosuberic acid bis-(2,2,2,-trifluoro-1-phenyl-1-trifluoromethyl-ethyl) ester (PFSE1), perfluorosuberic acid bis-[1-(4-trifluoromethyl-phenyl)-ethyl] ester (PFSE2) and a fluorinated phenylmethanediol diester (FPMD1), largely remained in a PHFHIPS film during the post-apply bake. The dissolution behavior of the two fluorinated diesters was studied and found to slow down the dissolution rate of PHFHIPS with inhibition factors of 1.9 and 1.6, respectively. The absorbance of PHFHIPS films containing 10 wt% of the diester inhibitors is 3.6 AU/micron compared with an absorbance of 3.3 AU/micron for the polymer itself. The absorbance of 10% FPMD1 in PHFHIPS was measured as 3.5 AU/micron compared with an absorbance of 3.4 AU/micron for the polymer itself. Thus, the non-volatility and transparency of the fluorinated inhibitors at 157 nm as well as their ability to reduce the development rate of fluorinated polymers make them suitable for use in a 157 nm resist system.

  11. Quantitative comparison of the OCT imaging depth at 1300 nm and 1600 nm

    PubMed Central

    Kodach, V. M.; Kalkman, J.; Faber, D. J.; van Leeuwen, T. G.

    2010-01-01

    One of the present challenges in optical coherence tomography (OCT) is the visualization of deeper structural morphology in biological tissues. Owing to a reduced scattering, a larger imaging depth can be achieved by using longer wavelengths. In this work, we analyze the OCT imaging depth at wavelengths around 1300 nm and 1600 nm by comparing the scattering coefficient and OCT imaging depth for a range of Intralipid concentrations at constant water content. We observe an enhanced OCT imaging depth for 1600 nm compared to 1300 nm for Intralipid concentrations larger than 4 vol.%. For higher Intralipid concentrations, the imaging depth enhancement reaches 30%. The ratio of scattering coefficients at the two wavelengths is constant over a large range of scattering coefficients and corresponds to a scattering power of 2.8 ± 0.1. Based on our results we expect for biological tissues an increase of the OCT imaging depth at 1600 nm compared to 1300 nm for samples with high scattering power and low water content. PMID:21258456

  12. Photolysis of formic acid at 355 nm

    NASA Astrophysics Data System (ADS)

    Martinez, Denhi; Bautista, Teonanacatl; Guerrero, Alfonso; Alvarez, Ignacio; Cisneros, Carmen

    2015-05-01

    Formic acid is well known as a food additive and recently an application on fuel cell technology has emerged. In this work we have studied the dissociative ionization process by multiphoton absorption of formic acid molecules at 355nm wavelength photons, using TOF spectrometry in reflectron mode (R-TOF). Some of the most abundant ionic fragments produced are studied at different settings of the laser harmonic generator. The dependence of the products on these conditions is reported. This work was supported by CONACYT Project 165410 and PAPIIT IN102613 and IN101215.

  13. 248nm silicon photoablation: Microstructuring basics

    NASA Astrophysics Data System (ADS)

    Poopalan, P.; Najamudin, S. H.; Wahab, Y.; Mazalan, M.

    2015-05-01

    248nm pulses from a KrF excimer laser was used to ablate a Si wafer in order to ascertain the laser pulse and energy effects for use as a microstructuring tool for MEMS fabrication. The laser pulses were varied between two different energy levels of 8mJ and 4mJ while the number of pulses for ablation was varied. The corresponding ablated depths were found to range between 11 µm and 49 µm, depending on the demagnified beam fluence.

  14. 248nm silicon photoablation: Microstructuring basics

    SciTech Connect

    Poopalan, P.; Najamudin, S. H.; Wahab, Y.; Mazalan, M.

    2015-05-15

    248nm pulses from a KrF excimer laser was used to ablate a Si wafer in order to ascertain the laser pulse and energy effects for use as a microstructuring tool for MEMS fabrication. The laser pulses were varied between two different energy levels of 8mJ and 4mJ while the number of pulses for ablation was varied. The corresponding ablated depths were found to range between 11 µm and 49 µm, depending on the demagnified beam fluence.

  15. 1085 nm Nd:YVO4 laser intracavity pumped at 914 nm and sum-frequency mixing to reach cyan laser at 496 nm

    NASA Astrophysics Data System (ADS)

    Lü, Y. F.; Xia, J.; Yin, X. D.; Wang, D.; Zhang, X. H.

    2010-01-01

    We present for the first time a Nd:YVO4 laser at 1085 nm intracavity pumped at 914 nm by a Nd:YVO4 laser. We obtained intracavity powers of 57 W at 914 nm and 62 W at 1085 nm. Using type-I critical phase-matching LiB3O5 (LBO) crystal, a cyan laser at 496 nm is obtained by 914 and 1085 nm intracavity sum-frequency mixing. The maximum laser output power of 142 mW is obtained when an incident pump laser of 19.6 W is used.

  16. Electrically-pumped 850-nm micromirror VECSELs.

    SciTech Connect

    Geib, Kent Martin; Peake, Gregory Merwin; Serkland, Darwin Keith; Keeler, Gordon Arthur; Mar, Alan

    2005-02-01

    Vertical-external-cavity surface-emitting lasers (VECSELs) combine high optical power and good beam quality in a device with surface-normal output. In this paper, we describe the design and operating characteristics of an electrically-pumped VECSEL that employs a wafer-scale fabrication process and operates at 850 nm. A curved micromirror output coupler is heterogeneously integrated with AlGaAs-based semiconductor material to form a compact and robust device. The structure relies on flip-chip bonding the processed epitaxial material to an aluminum nitride mount; this heatsink both dissipates thermal energy and permits high frequency modulation using coplanar traces that lead to the VECSEL mesa. Backside emission is employed, and laser operation at 850 nm is made possible by removing the entire GaAs substrate through selective wet etching. While substrate removal eliminates absorptive losses, it simultaneously compromises laser performance by increasing series resistance and degrading the spatial uniformity of current injection. Several aspects of the VECSEL design help to mitigate these issues, including the use of a novel current-spreading n type distributed Bragg reflector (DBR). Additionally, VECSEL performance is improved through the use of a p-type DBR that is modified for low thermal resistance.

  17. TCSPC FLIM in the wavelength range from 800 nm to 1700 nm (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Becker, Wolfgang; Shcheslavsky, Vladislav

    2016-03-01

    Excitation and detection in the wavelength range above 800nm is a convenient and relatively inexpensive way to increase the penetration depth in optical microscopy. Moreover, detection at long wavelength avoids the problem that tissue autofluorescence contaminates the signals from endogenous fluorescence probes. FLIM at NIR wavelength may therefore be complementary to multiphoton microscopy, especially if the lifetimes of NIR fluorophores report biological parameters of the tissue structures they are bound to. Unfortunately, neither the excitation sources nor the detectors of standard confocal and multiphoton laser scanning systems are directly suitable for excitation and detection of NIR fluorescence. Most of these problems can be solved, however, by using ps diode lasers or Ti:Sapphire lasers at their fundamental wavelength, and NIR-sensitive detectors. With NIR-sensitive PMTs the detection wavelength range can be extended up to 900 nm, with InGaAs SPAD detectors up to 1700 nm. Here, we demonstrate the use of a combination of laser scanning, multi-dimensional TCSPC, and advanced excitation sources and detectors for FLIM at up to 1700 nm. The performance was tested at tissue samples incubated with NIR dyes. The fluorescence lifetimes generally get shorter with increasing absorption and emission wavelengths of the dyes. For the cyanine dye IR1061, absorbing around 1060 nm, the lifetime was found to be as short as 70 ps. Nevertheless the fluorescence decay could still be clearly detected. Almost all dyes showed clear lifetime changes depending on the binding to different tissue constituents.

  18. Comparison of 980-nm and 1070-nm in endovenous laser treatment (EVLT)

    NASA Astrophysics Data System (ADS)

    Topaloglu, Nermin; Tabakoglu, Ozgur; Ergenoglu, Mehmet U.; Gülsoy, Murat

    2009-07-01

    The use of endovenous laser treatment for varicose veins has been increasing in recent years. It is a safer technique than surgical vein stripping. Its complications (e.g. bruising, pain) are less than the complications of surgical vein stripping. But best parameters such as optimum wavelength, power, and application duration are still under investigation to clarify uncertainties about this technique. To prevent its complications and improve its clinical outcomes, the exact mechanism of it has to be known. The aim of this study is to investigate the effect of different laser wavelengths on endovenous laser therapy. In this study 980-nm diode laser and 1070-nm fiber laser were used. Human veins were irradiated with 980-nm and 1070-nm lasers at 8 W and 10 W to find the optimal power and wavelength. After laser application, remarkable shrinkage was observed. Inner and outer diameters of the veins also narrowed for both of the laser types. 10 W of 980-nm laser application led to better shrinkage results.

  19. High power diode lasers emitting from 639 nm to 690 nm

    NASA Astrophysics Data System (ADS)

    Bao, L.; Grimshaw, M.; DeVito, M.; Kanskar, M.; Dong, W.; Guan, X.; Zhang, S.; Patterson, J.; Dickerson, P.; Kennedy, K.; Li, S.; Haden, J.; Martinsen, R.

    2014-03-01

    There is increasing market demand for high power reliable red lasers for display and cinema applications. Due to the fundamental material system limit at this wavelength range, red diode lasers have lower efficiency and are more temperature sensitive, compared to 790-980 nm diode lasers. In terms of reliability, red lasers are also more sensitive to catastrophic optical mirror damage (COMD) due to the higher photon energy. Thus developing higher power-reliable red lasers is very challenging. This paper will present nLIGHT's released red products from 639 nm to 690nm, with established high performance and long-term reliability. These single emitter diode lasers can work as stand-alone singleemitter units or efficiently integrate into our compact, passively-cooled Pearl™ fiber-coupled module architectures for higher output power and improved reliability. In order to further improve power and reliability, new chip optimizations have been focused on improving epitaxial design/growth, chip configuration/processing and optical facet passivation. Initial optimization has demonstrated promising results for 639 nm diode lasers to be reliably rated at 1.5 W and 690nm diode lasers to be reliably rated at 4.0 W. Accelerated life-test has started and further design optimization are underway.

  20. Dual illumination OCT at 1050nm and 840nm for whole eye segment imaging

    NASA Astrophysics Data System (ADS)

    Fan, Shanhui; Qin, Lin; Dai, Cuixia; Zhou, Chuanqing

    2014-11-01

    We presented an improved dual channel dual focus spectral domain optical coherence tomography (SD-OCT) with two illuminations at 840 nm and 1050 nm for whole eye segment imaging and biometry in vivo. The two light beams were coupled and optically optimized to scan the anterior and posterior segment of the eye simultaneously. This configuration with dichroic mirrors integrated in the sample arm enables us to acquire images from the anterior segment and retina effectively with minimum loss of sample signal. In addition, the full resolved complex (FRC) method was applied to double the imaging depth for the whole anterior segment imaging by eliminating the mirror image. The axial resolution for 1050 nm and 840 nm OCT was 14 μm and 8 μm in air, respectively. Finally, the system was successfully tested in imaging the unaccommodated and accommodated eyes. The preliminary results demonstrated the significant improvements comparing with our previous dual channel SD-OCT configuration in which the two probing beams had the same central wavelength of 840 nm.

  1. Tracking the photodissociation dynamics of liquid nitromethane at 266 nm by femtosecond time-resolved broadband transient grating spectroscopy

    NASA Astrophysics Data System (ADS)

    Wu, Honglin; Song, Yunfei; Yu, Guoyang; Wang, Yang; Wang, Chang; Yang, Yanqiang

    2016-05-01

    Femtosecond time-resolved transient grating (TG) technique was employed to get insight into the photodissociation mechanism of liquid nitromethane (NM). Broadband white-light continuum was introduced as the probe to observe the evolution of electronic excited states of NM molecules and the formation of photodissociation products simultaneously. The reaction channel of liquid NM under 266 nm excitation was obtained that NM molecules in excited state S2 relax through two channels: about 73% relax to low lying S1 state through S2/S1 internal conversion with a time constant of 0.24 ps and then go back to the ground state through S1/S0 internal conversion; the other 27% will dissociate with a time constant of 2.56 ps. NO2 was found to be one of the products from the experimental TG spectra, which confirmed that C-N bond rupture was the primary dissociation channel of liquid NM.

  2. Mutation of the nm23-H1 gene has a non-dominant role in colorectal adenocarcinoma

    PubMed Central

    JIN, YUELING; DAI, ZHENSHENG

    2016-01-01

    Nm23-H1 is a metastasis suppressor gene, which is has a reduced expression in patients with digestive system cancer. However, the mechanistic basis for the genetic instability remains unknown. To study the expression of the nm23-H1 gene in patients with colorectal cancer, polymerase chain reaction-single strand conformation polymorphism was used to analyze any point mutation, and immunohistochemistry was used to detect the expression of nm23-H1. Results revealed that all 63 specimens of Chinese human colorectal cancer tissues exhibit no point mutation. Among those 63 specimens, 19 (30%) exhibited positive immunostaining for the nm23-H1 protein and 44 (70%) exhibited negative immunostaining. These observations suggested that the protein and gene expression levels of nm23-H1 are reduced in colorectal cancer compared with the adjacent normal tissues, and the point mutation in the nm23-H1 gene is not the dominant cause of metastatic colorectal cancer. PMID:27330777

  3. 308-nm excimer laser in endodontics

    NASA Astrophysics Data System (ADS)

    Liesenhoff, Tim

    1992-06-01

    Root canal preparation was performed on 20 extracted human teeth. After opening the coronal pulp, the root canals were prepared by 308 nm excimer laser only. All root canals were investigated under SEM after separation in the axial direction. By sagittal separation of the mandibles of freshly slaughtered cows, it was possible to get access to the tissues and irradiate under optical control. Under irradiation of excimer laser light, tissue starts to fluoresce. It was possible to demonstrate that each tissue (dentin, enamel, bone, pulpal, and connective tissue) has a characteristic spectral pattern. The SEM analyses showed that it is well possible to prepare root canals safely. All organic soft tissue has been removed by excimer laser irradiation. There was no case of via falsa. The simultaneous spectroscopic identification of the irradiated tissue provides a safe protection from overinstrumentation. First clinical trials on 20 patients suffering of chronical apical parodontitis have been carried out successfully.

  4. 1064-nm Nd:YAG laser nucleotomy

    NASA Astrophysics Data System (ADS)

    Vari, Sandor G.; Pergadia, Vani R.; Shi, Wei-Qiang; Snyder, Wendy J.; Fishbein, Michael C.; Grundfest, Warren S.

    1993-07-01

    The high incidence of patients with clinical and neurological symptoms of lumbar disc herniation has spurred the development of less invasive and more cost efficient methods to treat patients. In this study we evaluated pulsed and continuous wave (cw) 1064 nm Nd:YAG laser ablation and induced thermal damage in sheep intervertebral disc. We used the Heraeus LaserSonics Hercules 5040 (Nd:YAG) laser system and 400 micrometers bare and 600 micrometers ball-tipped fibers in cw and pulsed mode. For the laser parameters and fibers used in this study, ablation of the intervertebral disc was successful and thermal damage did not exceed 0.5 mm. Varying beam diameters and focusing abilities (i.e., bare and ball) did not produce any difference in the coagulation thermal effect.

  5. Surface micromachined MEMS tunable VCSEL at 1550 nm with > 70 nm single mode tuning

    NASA Astrophysics Data System (ADS)

    Gierl, Christian; Gründl, Tobias; Debernardi, Pierluigi; Zogal, Karolina; Davani, Hooman A.; Grasse, Christian; Böhm, Gerhard; Meissner, Peter; Küppers, Franko; Amann, Markus-Christian

    2012-03-01

    We present surface micro-machined tunable vertical-cavity surface-emitting lasers (VCSELs) operating around 1550nm with tuning ranges up to 100nm and side mode suppression ratios beyond 40 dB. The output power reaches 3.5mW at 1555 nm. The electro-thermal and the electro-statical actuation of a micro electro-mechanical system (MEMS) movable distributed Bragg reflector (DBR) membrane increases/decreases the cavity length which shifts the resonant wavelength of the cavity to higher/lower values. The wavelength is modulated with 200 Hz/120 kHz. Both tuning mechanisms can be used simultaneously within the same device. The newly developed surface micro-machining technology uses competitive dielectric materials for the MEMS, deposited with low temperature plasma enhanced chemical vapor deposition (PECVD), which is cost effective and capable for on wafer mass production.

  6. Absorption Measurements of Periodically Poled Potassium Titanyl Phosphate (PPKTP) at 775 nm and 1550 nm

    PubMed Central

    Steinlechner, Jessica; Ast, Stefan; Krüger, Christoph; Singh, Amrit Pal; Eberle, Tobias; Händchen, Vitus; Schnabel, Roman

    2013-01-01

    The efficient generation of second-harmonic light and squeezed light requires non-linear crystals that have low absorption at the fundamental and harmonic wavelengths. In this work the photo-thermal self-phase modulation technique is exploited to measure the absorption coefficient of periodically poled potassium titanyl phosphate (PPKTP) at 1,550 nm and 775 nm. The measurement results are (84±40) ppm/cm and (127±24) ppm/cm, respectively. We conclude that the performance of state-of-the-art frequency doubling and squeezed light generation in PPKTP is not limited by absorption. PMID:23291574

  7. The Doubling of 846 nm Light to Produce 423 nm Light for use in Atom Interferometry

    NASA Astrophysics Data System (ADS)

    Archibald, James; Birrell, Jeremey; Tang, Rebecca; Erickson, Chris; Goggins, Landon; Durfee, Dallin

    2009-10-01

    We present progress on a 423 nm fluorescence probe/cooling laser for use in our neutral calcium atom interferometer. The finished system will include an 846 nm diode laser that is coupled to a tapered amplifier. This light will be sent to a buildup cavity where we will achieve second-harmonic generation (SHG) using either a BBO non-linear crystal or a periodically-poled KTP crystal. We will discuss the theoretical considerations relating to the doubling of light in a crystal and the construction of our buildup cavity. We will also discuss its proposed application for use in atom interferometry.

  8. Measurement of 100 nm and 60 nm Particle Standards by Differential Mobility Analysis

    PubMed Central

    Mulholland, George W.; Donnelly, Michelle K.; Hagwood, Charles R.; Kukuck, Scott R.; Hackley, Vincent A.; Pui, David Y. H.

    2006-01-01

    The peak particle size and expanded uncertainties (95 % confidence interval) for two new particle calibration standards are measured as 101.8 nm ± 1.1 nm and 60.39 nm ± 0.63 nm. The particle samples are polystyrene spheres suspended in filtered, deionized water at a mass fraction of about 0.5 %. The size distribution measurements of aerosolized particles are made using a differential mobility analyzer (DMA) system calibrated using SRM® 1963 (100.7 nm polystyrene spheres). An electrospray aerosol generator was used for generating the 60 nm aerosol to almost eliminate the generation of multiply charged dimers and trimers and to minimize the effect of non-volatile contaminants increasing the particle size. The testing for the homogeneity of the samples and for the presence of multimers using dynamic light scattering is described. The use of the transfer function integral in the calibration of the DMA is shown to reduce the uncertainty in the measurement of the peak particle size compared to the approach based on the peak in the concentration vs. voltage distribution. A modified aerosol/sheath inlet, recirculating sheath flow, a high ratio of sheath flow to the aerosol flow, and accurate pressure, temperature, and voltage measurements have increased the resolution and accuracy of the measurements. A significant consideration in the uncertainty analysis was the correlation between the slip correction of the calibration particle and the measured particle. Including the correlation reduced the expanded uncertainty from approximately 1.8 % of the particle size to about 1.0 %. The effect of non-volatile contaminants in the polystyrene suspensions on the peak particle size and the uncertainty in the size is determined. The full size distributions for both the 60 nm and 100 nm spheres are tabulated and selected mean sizes including the number mean diameter and the dynamic light scattering mean diameter are computed. The use of these particles for calibrating DMAs and for

  9. Atmospheric Aerosol Nucleation: Formation of Sub-3 nm Particles and Their Subsequent Growth

    NASA Astrophysics Data System (ADS)

    Lee, S.

    2012-12-01

    Aerosol nucleation is an important step in the chain reaction that lead to cloud formation but the nucleation mechanisms are poorly understand. Most of the previous aerosol nucleation studies were based on measurements of particles, typically larger than 3 nm, so it was unclear how gas phase molecules nucleate to form clusters and how they further grow to become aerosol particles. In this presentation, we will show recent results of aerosol nucleation based on direct measurements of sub-3 nm particles. We will show laboratory studies of multicomponent nucleation involving sulfuric acid, ammonia, and organic amines and atmospheric observations made in various atmospheric conditions (biogenic, marine, and less polluted continental atmosphere).

  10. Absorption coefficients for water vapor at 193 nm from 300 to 1073 K

    NASA Technical Reports Server (NTRS)

    Kessler, W. J.; Carleton, K. L.; Marinelli, W. J.

    1993-01-01

    Measurements of the water absorption coefficient at 193 nm from 300 to 1073 K are reported. The measurements were made using broadband VUV radiation and a monochromator-based detection system. The water vapor was generated by a saturator and metered into a flowing, 99 cm absorption cell via a water vapor mass flow meter. The 193 nm absorption coefficient measurements are compared to room temperature and high temperature shock tube measurements with good agreement. The absorption can be parameterized by a nu3 vibrational mode reaction coordinate and the thermal population of the nu3 mode.

  11. Photodissociation of the Propargyl (C3D3) Radicals at 248 nm and 193 nm

    SciTech Connect

    Neumark., D.M.; Crider, P.E.; Castiglioni, L.; Kautzman, K.K.

    2009-01-21

    The photodissociation of perdeuterated propargyl (D{sub 2}CCCD) and propynyl (D{sub 3}CCC) radicals was investigated using fast beam photofragment translational spectroscopy. Radicals were produced from their respective anions by photodetachment at 540 nm and 450 nm (below and above the electron affinity of propynyl). The radicals were then photodissociated by 248 nm or 193 nm light. The recoiling photofragments were detected in coincidence with a time- and position-sensitive detector. Three channels were observed: D{sub 2} loss, CD + C{sub 2}D{sub 2}, and CD{sub 3} + C{sub 2}. Obervation of the D loss channel was incompatible with this experiment and was not attempted. Our translational energy distributions for D{sub 2} loss peaked at nonzero translational energy, consistent with ground state dissociation over small (< 1 eV) exit barriers with respect to separated products. Translational energy distributions for the two heavy channels peaked near zero kinetic energy, indicating dissociation on the ground state in the absence of exit barriers.

  12. Evaluation of the Diode laser (810nm,980nm) on dentin tubule diameter following internal bleaching

    PubMed Central

    Kiomarsi, Nazanin; Salim, Soheil; Sarraf, Pegah; Javad-Kharazifard, Mohammad

    2016-01-01

    Background The aim of this study was to evaluate the effect of diode laser irradiation and bleaching materials on the dentinal tubule diameter after laser bleaching. Material and Methods The dentin discs of 40 extracted third molar were used in this experiment. Each disc surface was divided into two halves by grooving. Half of samples were laser bleached at different wavelengths with two different concentrations of hydrogen peroxide. Other half of each disc with no laser bleaching remained as a negative control. Dentin discs were assigned randomly into four groups (n=10) with following hydrogen peroxide and diode laser wavelength specifications; Group 1 (30% - 810 nm), group 2 (30% - 980 nm), group 3 (46% - 810 nm) and group 4 (46% - 980 nm). All specimens were sent for scanning electron microscopic (SEM) analysis in order to measure tubular diameter in laser treated and control halves. Data were analyzed by ANOVA and Tukey test (p<0.05). Results A significant reduction in dentin tubule diameter was observed in groups 1, 2 and 4. There was no significant difference between groups 1 and 2 and between groups 3 and 4 after bleaching. Conclusions The SEM results showed that diode laser was able to reduce dentin tubule diameter and its effect on dentin was dependent on chemical action of bleaching material. Key words:Laser, diode, dentin, tubule, diameter. PMID:27398172

  13. Characterization of LANDSAT Panels Using the NIST BRDF Scale from 1100 nm to 2500 nm

    NASA Technical Reports Server (NTRS)

    Markham, Brian; Tsai, Benjamin K.; Allen, David W.; Cooksey, Catherine; Yoon, Howard; Hanssen, Leonard; Zeng, Jinan; Fulton, Linda; Biggar, Stuart; Markham, Brian

    2010-01-01

    Many earth observing sensors depend on white diffuse reflectance standards to derive scales of radiance traceable to the St Despite the large number of Earth observing sensors that operate in the reflective solar region of the spectrum, there has been no direct method to provide NIST traceable BRDF measurements out to 2500 rim. Recent developments in detector technology have allowed the NIST reflectance measurement facility to expand the operating range to cover the 250 nm to 2500 nm range. The facility has been modified with and additional detector using a cooled extended range indium gallium arsenide (Extended InGaAs) detector. Measurements were made for two PTFE white diffuse reflectance standards over the 1100 nm to 2500 nm region at a 0' incident and 45' observation angle. These two panels will be used to support the OLI calibration activities. An independent means of verification was established using a NIST radiance transfer facility based on spectral irradiance, radiance standards and a diffuse reflectance plaque. An analysis on the results and associated uncertainties will be discussed.

  14. THE SPECTRUM OF THORIUM FROM 250 nm TO 5500 nm: RITZ WAVELENGTHS AND OPTIMIZED ENERGY LEVELS

    SciTech Connect

    Redman, Stephen L.; Nave, Gillian; Sansonetti, Craig J.

    2014-03-01

    We have made precise observations of a thorium-argon hollow cathode lamp emission spectrum in the region between 350 nm and 1175 nm using a high-resolution Fourier transform spectrometer. Our measurements are combined with results from seven previously published thorium line lists to re-optimize the energy levels of neutral, singly, and doubly ionized thorium (Th I, Th II, and Th III). Using the optimized level values, we calculate accurate Ritz wavelengths for 19, 874 thorium lines between 250 nm and 5500 nm (40, 000 cm{sup –1} to 1800 cm{sup –1}). We have also found 102 new thorium energy levels. A systematic analysis of previous measurements in light of our new results allows us to identify and propose corrections for systematic errors in Palmer and Engleman and typographical errors and incorrect classifications in Kerber et al. We also found a large scatter with respect to the thorium line list of Lovis and Pepe. We anticipate that our Ritz wavelengths will lead to improved measurement accuracy for current and future spectrographs that make use of thorium-argon or thorium-neon lamps as calibration standards.

  15. Faster qualification of 193-nm resists for 100-nm development using photo cell monitoring

    NASA Astrophysics Data System (ADS)

    Jones, Chris M.; Kallingal, Chidam; Zawadzki, Mary T.; Jeewakhan, Nazneen N.; Kaviani, Nazila N.; Krishnan, Prakash; Klaum, Arthur D.; Van Ess, Joel

    2003-05-01

    The development of 100-nm design rule technologies is currently taking place in many R&D facilities across the world. For some critical alyers, the transition to 193-nm resist technology has been required to meet this leading edge design rule. As with previous technology node transitions, the materials and processes available are undergoing changes and improvements as vendors encounter and solve problems. The initial implementation of the 193-nm resits process did not meet the photolithography requirements of some IC manufacturers due to very high Post Exposure Bake temperature sensitivity and consequently high wafer to wafer CD variation. The photoresist vendors have been working to improve the performance of the 193-nm resists to meet their customer's requirements. Characterization of these new resists needs to be carried out prior to implementation in the R&D line. Initial results on the second-generation resists evaluated at Cypress Semicondcutor showed better CD control compared to the aelrier resist with comparable Depth of Focus (DOF), Exposure Latitute, Etch Resistance, etc. In addition to the standard lithography parameters, resist characterization needs to include defect density studies. It was found that the new resists process with the best CD control, resulted in the introduction of orders of magnitude higher yield limiting defects at Gate, Contact adn Local Interconnect. The defect data were shared with the resists vendor and within days of the discovery the resist vendor was able to pinpoint the source of the problem. The fix was confirmed and the new resists were successfully released to production. By including defect monitoring into the resist qualification process, Cypress Semiconductor was able to 1) drive correction actions earlier resulting in faster ramp and 2) eliminate potential yield loss. We will discuss in this paper how to apply the Micro Photo Cell Monitoring methodology for defect monitoring in the photolithogprhay module and the

  16. Quantum yield for carbon monoxide production in the 248 nm photodissociation of carbonyl sulfide (OCS)

    NASA Technical Reports Server (NTRS)

    Zhao, Z.; Stickel, R. E.; Wine, P. H.

    1995-01-01

    Tunable diode laser absorption spectroscopy has been coupled with excimer laser flash photolysis to measure the quantum yield for CO production from 248 nm photodissociation of carbonyl sulfide (OCS) relative to the well-known quantum yield for CO production from 248 nm photolysis of phosgene (Cl2CO2). The temporal resolution of the experiments was sufficient to distinguish CO formed directly by photodissociation from that formed by subsequent S((sup 3)P(sub J)) reaction with OCS. Under the experimental conditions employed, CO formation via the fast S((sup 1)D(sub 2)) + OCS reaction was minimal. Measurements at 297K and total pressures from 4 to 100 Torr N2 + N2O show the CO yield to be greater than 0.95 and most likely unity. This result suggests that the contribution of OCS as a precursor to the lower stratospheric sulfate aerosol layer is somewhat larger than previously thought.

  17. Multi-watt 589nm fiber laser source

    SciTech Connect

    DAWSON, J W; DROBSHOFF, A D; BEACH, R J; MESSERLY, M J; PAYNE, S A; BROWN, A; PENNINGTON, D M; BAMFORD, D J; SHARPE, S J; COOK, D J

    2006-01-19

    We have demonstrated 3.5W of 589nm light from a fiber laser using periodically poled stoichiometric Lithium Tantalate (PPSLT) as the frequency conversion crystal. The system employs 938nm and 1583nm fiber lasers, which were sum-frequency mixed in PPSLT to generate 589nm light. The 938nm fiber laser consists of a single frequency diode laser master oscillator (200mW), which was amplified in two stages to >15W using cladding pumped Nd{sup 3+} fiber amplifiers. The fiber amplifiers operate at 938nm and minimize amplified spontaneous emission at 1088nm by employing a specialty fiber design, which maximizes the core size relative to the cladding diameter. This design allows the 3-level laser system to operate at high inversion, thus making it competitive with the competing 1088nm 4-level laser transition. At 15W, the 938nm laser has an M{sup 2} of 1.1 and good polarization (correctable with a quarter and half wave plate to >15:1). The 1583nm fiber laser consists of a Koheras 1583nm fiber DFB laser that is pre-amplified to 100mW, phase modulated and then amplified to 14W in a commercial IPG fiber amplifier. As a part of our research efforts we are also investigating pulsed laser formats and power scaling of the 589nm system. We will discuss the fiber laser design and operation as well as our results in power scaling at 589nm.

  18. Infrared Luminescence at 1010 nm and 1500 nm in LiNbO3:Er3+ Excitted by Short Pulse Radiation at 980 nm

    NASA Astrophysics Data System (ADS)

    Kokanyan, E. P.; Demirkhanyan, G. G.; Steveler, E.; Rinnert, H.; Aillerie, M.

    Luminescence of LiNbO3:Er3+ crystal at a wavelength of 1010 nm and 1500 nm under pulsed excitation of different power at a wavelength of 980 nm are experimentally and theoretically studied. It is revealed, that the main part of the absorbed energy gives rise to the luminescence at 1500 nm. Considered concentrations of Er3+ impurity ions allow to exclude cooperative processes in the impurity subsystem. The experimental results are interpreted in the framework of a three electronic levels system, assuming that the population of the higher lasing level 4I13/2 in the crystal under study is caused by relaxation processes from the excited level. It is shown that for obtaining of a laser radiation at about 1500 nm one can effectively use a pulse-pumping at 980 nm with a power density in a range of 50 ÷ 60 MW/cm2.

  19. FY09 assessment of mercury reduction at SNL/NM.

    SciTech Connect

    McCord, Samuel Adam

    2010-02-01

    This assessment takes the result of the FY08 performance target baseline of mercury at Sandia National Laboratories/New Mexico, and records the steps taken in FY09 to collect additional data, encourage the voluntary reduction of mercury, and measure success. Elemental (metallic) mercury and all of its compounds are toxic, and exposure to excessive levels can permanently damage or fatally injure the brain and kidneys. Elemental mercury can also be absorbed through the skin and cause allergic reactions. Ingestion of inorganic mercury compounds can cause severe renal and gastrointestinal damage. Organic compounds of mercury such as methyl mercury, created when elemental mercury enters the environment, are considered the most toxic forms of the element. Exposures to very small amounts of these compounds can result in devastating neurological damage and death.1 SNL/NM is required to report annually on the site wide inventory of mercury for the Environmental Protection Agency's (EPA) Toxics Release Inventory (TRI) Program, as the site's inventory is excess of the ten pound reportable threshold quantity. In the fiscal year 2008 (FY08) Pollution Prevention Program Plan, Section 5.3 Reduction of Environmental Releases, a performance target stated was to establish a baseline of mercury, its principle uses, and annual quantity or inventory. This was accomplished on July 29, 2008 by recording the current status of mercury in the Chemical Information System (CIS).

  20. Modeling chemically amplified resists for 193-nm lithography

    NASA Astrophysics Data System (ADS)

    Croffie, Ebo H.; Cheng, Mosong; Neureuther, Andrew R.; Houlihan, Francis M.; Cirelli, Raymond A.; Sweeney, James R.; Dabbagh, Gary; Watson, Pat G.; Nalamasu, Omkaram; Rushkin, Ilya L.; Dimov, Ognian N.; Gabor, Allen H.

    2000-06-01

    Post exposure bake (PEB) models in the STORM program have been extended to study pattern formation in 193 nm chemically amplified resists. Applications to resists formulated with cycloolefin-maleic anhydride copolymers, cholate based dissolution inhibitor, nonaflate photoacid generator and base quencher are presented. The PEB modeling is based on the chemical and physical mechanisms including the thermally induced deprotection reaction, acid loss due to base neutralization and protected-sites-enhanced acid diffusion. Simplifying assumptions are made to derive analytical expressions for PEB. The model parameters are extracted from the following experiments. UV-visible spectroscopy is used to extract the resist absorbance parameters. The generation of acid is monitored using the method of 'base additions.' The extent of deprotection that occurs during the bake is determined by monitoring the characteristic FTIR absorbance band around 1170 cm-1 over a range of exposure doses and bake temperatures. Diffusion parameters are extracted from line end shortening (LES) measurements. These parameters are optimized using the Method of Feasible Directions algorithm. Application results show good agreement with experimental data for different LES features.

  1. Synthesis of WS2 Nanowires as Efficient 808 nm-Laser-Driven Photothermal Nanoagents.

    PubMed

    Macharia, Daniel K; Yu, Nuo; Zhong, Runzhi; Xiao, Zhiyin; Yang, Jianmao; Chen, Zhigang

    2016-06-01

    A prerequisite for the development of photothermal ablation therapy for cancer is to obtain efficient photothermal nanoagents that can be irradiated by near-infrared (NIR) laser. Herein, we have reported the synthesis of WS2 nanowires as photothermal nanoagents by the reaction of WCl6 with CS2 in oleylamine at 280 degrees C. WS2 nanowires have the thickness of -2 nm and length of -100 nm. Importantly, the chloroform dispersion of WS2 nanowires exhibits strong photoabsorption in NIR region. The temperature of the dispersion (0.10-0.50 mg/mL) can increase by 12.8-23.9 degrees C in 5 min under the irradiation of 808 nm laser with a power density of 0.80 W/cm2. Therefore, WS2 nanowires have a great superiority as a new nanoagent for NIR-induced photothermal ablation of cancer, due to their small size and excellent photothermal performance. PMID:27427645

  2. Developing multi-layer mirror technology near 45 nm using Sc/Si interfaces

    SciTech Connect

    Nilsen, J; Jankowski, A; Friedman, L; Walton, C C

    2004-02-12

    Given the existing X-ray laser sources near 45 nm it would be useful to produce efficient X-ray optics in the 35 to 50 nm wavelength range that could be utilized in new applications. In this work we are developing the process to stabilize the interfaces of nanolaminate structures using materials such as Sc and Si. These materials will enable us to develop new multi-layer mirror technology that can be used in the wavelength range near 45 nm. To obtain this objective, the interfacial structure and reaction kinetics must first be well understood and then controlled for design applications. In this work we fabricate several Sc/Si multi-layer mirrors with and without a B{sub 4}C barrier layer. The structure and reflectivity of the mirrors are analyzed.

  3. Studies on a cross-linking type positive 193nm photoresist material

    NASA Astrophysics Data System (ADS)

    Wang, Liyuan; Guo, Xin; Chu, Zhanxing; Wang, Wenjun

    2006-03-01

    A kind of diacid, acrylpimaric acid, with condensed alicyclic structure and good film-forming property, was prepared by the Diels-Alder reaction of abietic acid and acrylic acid. In their solid film, the diacid can react with divinyl ether, such as 1,3-divinyloxyethoxybenzene when baked above 80 °C and become insoluble in dilute aqueous base. Thus formed compound can be quickly decomposed at the presence of strong acid generated by PAG above 100 °C and become easily soluble in dilute aqueous base. A positive photoresist can be formed by the diacid, divinyl ether and PAG. The measured photosensitivity is less than 50 mj/cm2 when exposed to low pressure Hg lamp (254nm). The diacid mixture displayed lower transparency than estimated at 193 nm and should be further purified to be used in 193 nm photoresist.

  4. Fast dispersion encoded full range OCT for retinal imaging at 800 nm and 1060 nm

    NASA Astrophysics Data System (ADS)

    Hofer, Bernd; Považay, Boris; Unterhuber, Angelika; Wang, Ling; Hermann, Boris; Rey, Sara; Matz, Gerald; Drexler, Wolfgang

    2011-03-01

    The dispersion mismatch between sample and reference arm in frequency-domain OCT can be used to iteratively suppress complex conjugate artifacts and thereby increase the imaging range. We propose a fast dispersion encoded full range (DEFR) algorithm that detects multiple signal components per iteration. The influence of different dispersion levels on the reconstruction quality is analyzed for in vivo retinal tomograms at 800 nm. Best results have been achieved with about 30 mm SF11, with neglectable resolution decrease due to finite resolution of the spectrometer. Our fast DEFR algorithm achieves an average suppression ratio of 55 dB and converges within 5 to 10 iterations. The processing time on non-dedicated hardware was 5 to 10 seconds for tomograms with 512 depth scans and 4096 sampling points per depth scan. Application of DEFR to the more challenging 1060 nm wavelength region is demonstrated by introducing an additional optical fibre in the sample arm.

  5. Polarization properties of lidar scattering from clouds at 347 nm and 694 nm.

    PubMed

    Pal, S R; Carswell, A I

    1978-08-01

    The polarization characteristics of lidar scattering from cumulus and low-lying shower clouds have been measured with a system operating at 694 nm (red) and 347 nm (blue). The backscatter profiles of the polarization components as well as of the total intensity of the return are presented and discussed for the two wavelengths. The linear depolarization ratio delta, which can be used as a measure of the unpolarized multiple scattering, has been obtained at both wavelengths. This quantity has a very low value at cloud base for both wavelengths and increases with pulse penetration. The blue registers generally higher values of a within the cloud. The measured total intensity backscatter functions for both wavelengths are presented and discussed in relation to theoretical calculations of cloud models. PMID:20203781

  6. TUNABLE DIODE LASER MEASUREMENTS OF NO2 NEAR 670 NM AND 395 NM. (R823933)

    EPA Science Inventory

    Two single-mode diode lasers were used to record high-resolution absorption spectra of NO2 (dilute in Ar) near 670.2 and 394.5 nm over a range of temperatures (296 to 774 K) and total pressures (2.4 x 10(-2) to 1 atm). A commercial InGaAsP laser was tuned 1.3 cm(-1) at a repetiti...

  7. Analysis of multi-mode to single-mode conversion at 635 nm and 1550 nm

    NASA Astrophysics Data System (ADS)

    Zamora, Vanessa; Bogatzki, Angelina; Arndt-Staufenbiel, Norbert; Hofmann, Jens; Schröder, Henning

    2016-03-01

    We propose two low-cost and robust optical fiber systems based on the photonic lantern (PL) technology for operating at 635 nm and 1550 nm. The PL is an emerging technology that couples light from a multi-mode (MM) fiber to several single-mode (SM) fibers via a low-loss adiabatic transition. This bundle of SM fibers is observed as a MM fiber system whose spatial modes are the degenerate supermodes of the bundle. The adiabatic transition allows that those supermodes evolve into the modes of the MM fiber. Simulations of the MM fiber end structure and its taper transition have been performed via functional mode solver tools in order to understand the modal evolution in PLs. The modelled design consists of 7 SM fibers inserted into a low-index capillary. The material and geometry of the PLs are chosen such that the supermodes match to the spatial modes of the desired step-index MM fiber in a moderate loss transmission. The dispersion of materials is also considered. These parameters are studied in two PL systems in order to reach a spectral transmission from 450 nm to 1600 nm. Additionally, an analysis of the geometry and losses due to the mismatching of modes is presented. PLs are typically used in the fields of astrophotonics and space photonics. Recently, they are demonstrated as mode converters in telecommunications, especially focusing on spatial division multiplexing. In this study, we show the use of PLs as a promising interconnecting tool for the development of miniaturized spectrometers operating in a broad wavelength range.

  8. Electron-induced single event upsets in 28 nm and 45 nm bulk SRAMs

    DOE PAGESBeta

    Trippe, J. M.; Reed, R. A.; Austin, R. A.; Sierawski, B. D.; Weller, R. A.; Funkhouser, E. D.; King, M. P.; Narasimham, B.; Bartz, B.; Baumann, R.; et al

    2015-12-01

    In this study, we present experimental evidence of single electron-induced upsets in commercial 28 nm and 45 nm CMOS SRAMs from a monoenergetic electron beam. Upsets were observed in both technology nodes when the SRAM was operated in a low power state. The experimental cross section depends strongly on both bias and technology node feature size, consistent with previous work in which SRAMs were irradiated with low energy muons and protons. Accompanying simulations demonstrate that δ-rays produced by the primary electrons are responsible for the observed upsets. Additional simulations predict the on-orbit event rates for various Earth and Jovian environmentsmore » for a set of sensitive volumes representative of current technology nodes. The electron contribution to the total upset rate for Earth environments is significant for critical charges as high as 0.2 fC. This value is comparable to that of sub-22 nm bulk SRAMs. Similarly, for the Jovian environment, the electron-induced upset rate is larger than the proton-induced upset rate for critical charges as high as 0.3 fC.« less

  9. Electron-induced single event upsets in 28 nm and 45 nm bulk SRAMs

    SciTech Connect

    Trippe, J. M.; Reed, R. A.; Austin, R. A.; Sierawski, B. D.; Weller, R. A.; Funkhouser, E. D.; King, M. P.; Narasimham, B.; Bartz, B.; Baumann, R.; Schrimpf, R. D.; Labello, R.; Nichols, J.; Weeden-Wright, S. L.

    2015-12-01

    In this study, we present experimental evidence of single electron-induced upsets in commercial 28 nm and 45 nm CMOS SRAMs from a monoenergetic electron beam. Upsets were observed in both technology nodes when the SRAM was operated in a low power state. The experimental cross section depends strongly on both bias and technology node feature size, consistent with previous work in which SRAMs were irradiated with low energy muons and protons. Accompanying simulations demonstrate that δ-rays produced by the primary electrons are responsible for the observed upsets. Additional simulations predict the on-orbit event rates for various Earth and Jovian environments for a set of sensitive volumes representative of current technology nodes. The electron contribution to the total upset rate for Earth environments is significant for critical charges as high as 0.2 fC. This value is comparable to that of sub-22 nm bulk SRAMs. Similarly, for the Jovian environment, the electron-induced upset rate is larger than the proton-induced upset rate for critical charges as high as 0.3 fC.

  10. Demonstration of a high output power 1533nm optical parametric oscillator pumped at 1064nm

    NASA Astrophysics Data System (ADS)

    Foltynowicz, Robert J.; Wojcik, Michael D.

    2010-10-01

    A high output power, eye-safe, LIDAR transmitter based on a KTA optical parametric oscillator (OPO) was demonstrated. The OPO was based on a two crystal, NCPM, KTA ring cavity which was doubly resonant. A 7ns, 30Hz, flashlamp-pumped, Q-switched Nd:YAG laser was injection seeded and used to pump the OPO. The OPO converted the 1064 nm pump beam into a 1533 nm signal wave and 3475 nm idler wave. In addition to demonstrating a high power OPO system, we investigated the effects of seeding the pump laser on the OPO's conversion efficiency, oscillation threshold, maximum signal power, and beam quality. The power conversion efficiency between the signal and the injection seeded pump was 22% with an oscillation threshold of 104 MW/cm2 (500 mJ) and a maximum signal power of 6.44 W (215 mJ). The power conversion efficiency between the signal and the unseeded pump was 24% with an oscillation threshold of 77 MW/cm2 (367mJ) and a maximum signal power of 7 W (233 mJ). The beam quality of the signal beam was produced an M2 =15. When the pump laser was seeded, the full angle divergence improved by nearly a factor of five.

  11. Production of OH from photolysis of HOCl at 307-309 nm

    NASA Technical Reports Server (NTRS)

    Molina, M. J.; Ishiwata, T.; Molina, L. T.

    1980-01-01

    Laser-induced fluorescence has been used to measure the amount of OH produced in the laser photolysis of HOCl at 310 nm. The HOCl was generated by the Cl2O + H2O and by the HCl + Cl2O reactions. The laser technique samples OH on a microsecond time scale so that secondary radical reactions cannot contribute significantly to the observed signals. The fluorescence signals were calibrated with O3-H2O mixtures, the reactions O3 + h(nu) yields O(1D) + O2 and O(1D) + H2O yields 2OH yielding known amounts of OH. The value for the absorption cross section of HOCl at 310 nm has been determined to be 6 x 10 to the -20th sq cm, assuming K(eq) = 0.082 for the Cl2O + H2O yields 2HOCl system and assuming unit quantum yield for the production of OH. The present investigation further supports earlier experimental work concluding that HOCl will photodissociate rapidly and will not be an important holding tank for chlorine in the stratosphere. These results are in disagreement with theoretical calculations of the UV absorption spectrum of HOCl in the 300-350-nm wavelength region.

  12. Immunosuppressive effects of ultraviolet (280-320 nm) radiation and psoralen plus ultraviolet (320-400 nm) radiation in mice.

    PubMed

    Kripke, M L

    1982-07-01

    Contact hypersensitivity (CHS), a cell-mediated immunologic reaction, can be induced in mice by application of a contact-sensitizing chemical to the shaved skin. Exposing the animals to UV radiation from FS40 sunlamps inhibits this immune response. This inhibition is systemic, since the sensitizer need not be applied to the irradiated site of the animal. The mechanism whereby UV radiation prevents CHS appears to involve the production of suppressor T-lymphocytes. Recent evidence suggests that UV exposure of mice alters the way in which certain antigens are processed, and this altered processing or presentation of antigen results in the activation of the suppressor cell pathway, rather than leading to immunization. Treatment of mice with a photosensitizer, psoralen, plus UV (320-400 nm) radiation also suppresses CHS systemically, but whether the cellular mechanisms are the same as those underlying the suppression from the shorter UV wavelengths remains to be determined. The possible role of these immunosuppressive events in photocarcinogenesis is discussed. PMID:6212709

  13. Designing dual-trench alternating phase-shift masks for 140-nm and smaller features using 248-nm KrF and 193-nm ArF lithography

    NASA Astrophysics Data System (ADS)

    Petersen, John S.; Socha, Robert J.; Naderi, Alex R.; Baker, Catherine A.; Rizvi, Syed A.; Van Den Broeke, Douglas J.; Kachwala, Nishrin; Chen, J. Fung; Laidig, Thomas L.; Wampler, Kurt E.; Caldwell, Roger F.; Takeuchi, Susumu; Yamada, Yoshiro; Senoh, Takashi; McCallum, Martin

    1998-09-01

    One method for making the alternating phase-shift mask involves cutting a trench into the quartz of the mask using an anisotropic dry etch, followed by an isotropic etch to move the corners of the trench underneath the chrome to minimize problems caused by diffraction at the bottom corners of the phase-trench. This manufacturing method makes the addition of subresolution scattering bars and serifs problematic, because the amount of the undercut causes chrome lifting of these small features. Adding an additional anisotropically etched trench to both cut and uncut regions is helpful, but the etch does not move the trench corners under the chrome and result in a loss to intensity and image contrast. At 248 nm illumination and 4X magnification, our work shows that a combination of 240 nm dual-trench and 5 nm to 10 nm undercut produces images with equal intensity between shifted and unshifted regions without loss of image contrasts. This paper demonstrates optical proximity correction for doing 100 nm, 120 nm, 140 nm and 180 nm lines of varying pitch for a simple alternating phase-shift mask, with no dual-trench or undercut. Then the electromagnetic field simulator, TEMPEST, is used to find the best combination of dual-trench depth and amount of undercut for an alternating phase-shift mask. Phase measurement using 248 nm light and depth measurement of thirty-six unique combinations of dual-trench and phase-shift trench are shown. Based on modeling and experimental results, recommendations for making a fine tuned dual-trench 248 nm mask, as well as an extension of the dual-trench alternating phase-shift technique to 193 nm lithography, are made.

  14. The OH + HBr reaction revisited

    NASA Technical Reports Server (NTRS)

    Ravishankara, A. R.; Wine, P. H.; Wells, J. R.

    1985-01-01

    Variable-temperature measurements of the rate coefficient /k(1)/ for the reaction OH + HBr yield Br + H2O are presented. The measurements are verified by two techniques: one involved a 266-nm pulsed-laser photolysis of O3/H2O/HBr/He mixtures in conjunction with time-resolved resonance fluorescence detection of OH, the second comprised pulsed laser-induced fluorescence detection of OH following 248-nm pulsed-laser photolysis of H2O2/HBr/Ar mixtures. It is reported that k(1) = (11.9 + or -1.4 x 10 to the -12th (cu cm)/(molecule)(s) independent of temperature. The measurements are compared with other available results.

  15. First principles study on the interfacial properties of NM/graphdiyne (NM = Pd, Pt, Rh and Ir): The implications for NM growing

    NASA Astrophysics Data System (ADS)

    Lu, Zhansheng; Li, Shuo; Lv, Peng; He, Chaozheng; Ma, Dongwei; Yang, Zongxian

    2016-01-01

    Based on the dispersion-corrected density functional calculations (DFT-D), we systematically studied the adsorption of noble metals (NM), Pd, Pt, Rh and Ir, on graphdiyne (GDY). We present a systematic study on the geometry, embedded adsorption energy and electronic structure of four different adatoms adsorbed on the GDY. The strong interaction between the NM adatoms and the GDY substrate is found with the NM embedded in the 18C-hexagon of the GDY. We investigated the mobility of the NM adatoms on the GDY, and found that the mobility barrier energy increases along with the increasing of the embedded adsorption energy. We present the NM adatoms growth of high concentrations on the GDY. Upon the analysis of the electronic structure and the frontier molecular orbitals, Rh and Ir adatoms of low concentrations (about 1.37 at%) on the GDY have the potential to be applied as single metal catalysts or gas molecule sensors.

  16. Picosecond laser texturization of mc-silicon for photovoltaics: A comparison between 1064 nm, 532 nm and 355 nm radiation wavelengths

    NASA Astrophysics Data System (ADS)

    Binetti, Simona; Le Donne, Alessia; Rolfi, Andrea; Jäggi, Beat; Neuenschwander, Beat; Busto, Chiara; Frigeri, Cesare; Scorticati, Davide; Longoni, Luca; Pellegrino, Sergio

    2016-05-01

    Self-organized surface structures were produced by picosecond laser pulses on multi-crystalline silicon for photovoltaic applications. Three different laser wavelengths were employed (i.e. 1064 nm, 532 nm and 355 nm) and the resulting morphologies were observed to effectively reduce the reflectivity of the samples after laser irradiation. Besides, a comparative study of the laser induced subsurface damage generated by the three different wavelengths was performed by confocal micro-Raman, photoluminescence and transmission electron microscopy. The results of both the structural and optical characterization showed that the mc-Si texturing performed with the laser at 355 nm provides surface reflectivity between 11% and 8% over the spectral range from 400 nm to 1 μm, while inducing the lowest subsurface damage, located above the depletion region of the p-n junction.

  17. The electrochemisty of surface modified <10 nm metal oxide nanoparticles

    NASA Astrophysics Data System (ADS)

    Roberts, Joseph J. P.

    and ZrO2 nanoparticles was also explored, but resulted in very low surface coverages. ZrO2 nanoparticles were also ferrocene tagged using previously discussed siloxane chemistry as well as a new route using click chemistry with an azo-phosphate ligand. A similar approach was taken with hydrolytically synthesized IrO 2 and is included for comparison. Chapter Five studies the multivalent electrochemistry of 4 nm magnetite nanoparticles. These nanoparticles are synthesized via thermal degradation and capped with citric acid to make them water soluble. pH dependent electrochemistry was discovered and characterized using cyclic voltammetry, chronoamperometry, and rotating disk electrode experiments. Two separate electrochemical species are present and undergo two irreversible, but separate electrochemical reactions; Fe(II) → Fe (III) and Fe(III) → Fe(II).

  18. Challenges in the Plasma Etch Process Development in the sub-20nm Technology Nodes

    NASA Astrophysics Data System (ADS)

    Kumar, Kaushik

    2013-09-01

    For multiple generations of semiconductor technologies, RF plasmas have provided a reliable platform for critical and non-critical patterning applications. The electron temperature of processes in a RF plasma is typically several electron volts. A substantial portion of the electron population is within the energy range accessible for different types of electron collision processes, such as electron collision dissociation and dissociative electron attachment. When these electron processes occur within a small distance above the wafer, the neutral species, radicals and excited molecules, generated from these processes take part in etching reactions impacting selectivity, ARDE and micro-loading. The introduction of finFET devices at 22 nm technology node at Intel marks the transition of planar devices to 3-dimensional devices, which add to the challenges to etch process in fabricating such devices. In the sub-32 nm technology node, Back-end-of-the-line made a change with the implementation of Trench First Metal Hard Mask (TFMHM) integration scheme, which has hence gained traction and become the preferred integration of low-k materials for BEOL. This integration scheme also enables Self-Aligned Via (SAV) patterning which prevents via CD growth and confines via by line trenches to better control via to line spacing. In addition to this, lack of scaling of 193 nm Lithography and non-availability of EUV based lithography beyond concept, has placed focus on novel multiple patterning schemes. This added complexity has resulted in multiple etch schemes to enable technology scaling below 80 nm Pitches, as shown by the memory manufacturers. Double-Patterning and Quad-Patterning have become increasingly used techniques to achieve 64 nm, 56 nm and 45 nm Pitch technologies in Back-end-of-the-line. Challenges associated in the plasma etching of these multiple integration schemes will be discussed in the presentation. In collaboration with A. Ranjan, TEL Technology Center, America

  19. Suppression of high-order-harmonic intensities observed in aligned CO2 molecules with 1300-nm and 800-nm pulses

    NASA Astrophysics Data System (ADS)

    Kato, Kosaku; Minemoto, Shinichirou; Sakai, Hirofumi

    2011-08-01

    High-order-harmonic generation from aligned N2, O2, and CO2 molecules is investigated by 1300-nm and 800-nm pulses. The harmonic intensities of 1300-nm pulses from aligned molecules show harmonic photon energy dependence similar to those of 800-nm pulses. Suppression of harmonic intensity from aligned CO2 molecules is observed for both 1300- and 800-nm pulses over the same harmonic photon energy range. As the dominant mechanism for the harmonic intensity suppression from aligned CO2 molecules, the present results support the two-center interference picture rather than the dynamical interference picture.

  20. Flux-calibration of medium-resolution spectra from 300 nm to 2500 nm

    NASA Astrophysics Data System (ADS)

    Moehler, Sabine; Modigliani, Andrea; Freudling, Wolfram; Giammichele, Noemi; Gianninas, Alexandros; Gonneau, Anais; Kausch, Wolfgang; Lançon, Ariane; Noll, Stefan; Rauch, Thomas; Vinther, Jakob

    2014-08-01

    While the near-infrared wavelength regime is becoming more and more important for astrophysics there are few spectrophotometric standard star data available to flux calibrate such data. On the other hand flux calibrating high-resolution spectra is a challenge even in the optical wavelength range, because the available flux standard data are often too coarsely sampled. We describe a method to obtain reference spectra derived from stellar model atmospheres, which allow users to derive response curves from 300 nm to 2500 nm also for high-resolution spectra. We verified that they provide an appropriate description of the observed standard star spectra by checking for residuals in line cores and line overlap regions in the ratios of observed spectra to model spectra. The finally selected model spectra are then empirically corrected for remaining mismatches and photometrically calibrated using independent observations. In addition we have defined an automatic method to correct for moderate telluric absorption using telluric model spectra with very high spectral resolution, that can easily be adapted to the observed data. This procedure eliminates the need to observe telluric standard stars, as long as some knowledge on the target spectrum exists.

  1. Sub-1 nm Nickel Molybdate Nanowires as Building Blocks of Flexible Paper and Electrochemical Catalyst for Water Oxidation.

    PubMed

    Liu, Huiling; Li, Haoyi; He, Peilei; Wang, Xun

    2016-02-24

    Sub-1 nm, extremely long nickel molybdate nanowires are synthesized based on a good/poor solvent system. The ultrathin nanowires can be hierarchically assembled into flexible, free-standing films with good mechanical properties. Compared with the large-size counterpart, nickel molybdate ultrathin nanowires display promising oxygen evolution reaction catalytic performance derived from the ultrathin feature. PMID:26724910

  2. Novel high refractive index fluids for 193nm immersion lithography

    NASA Astrophysics Data System (ADS)

    Santillan, Julius; Otoguro, Akihiko; Itani, Toshiro; Fujii, Kiyoshi; Kagayama, Akifumi; Nakano, Takashi; Nakayama, Norio; Tamatani, Hiroaki; Fukuda, Shin

    2006-03-01

    Despite the early skepticism towards the use of 193-nm immersion lithography as the next step in satisfying Moore's law, it continuous to meet expectations on its feasibility in achieving 65-nm nodes and possibly beyond. And with implementation underway, interest in extending its capability for smaller pattern sizes such as the 32-nm node continues to grow. In this paper, we will discuss the optical, physical and lithographic properties of newly developed high index fluids of low absorption coefficient, 'Babylon' and 'Delphi'. As evaluated in a spectroscopic ellipsometer in the 193.39nm wavelength, the 'Babylon' and 'Delphi' high index fluids were evaluated to have a refractive index of 1.64 and 1.63 with an absorption coefficient of 0.05/cm and 0.08/cm, respectively. Lithographic evaluation results using a 193-nm 2-beam interferometric exposure tool show the imaging capability of both high index fluids to be 32-nm half pitch lines and spaces.

  3. Temperature characteristic of 808nm VCSELs with large aperture

    NASA Astrophysics Data System (ADS)

    Feng, Yuan; Feng, Dawei; Hao, Yongqin; Wang, Yong; Yan, Changling; Lu, Peng; Li, Yang

    2015-03-01

    In order to study the output characteristics of 808nm vertical cavity surface emitting laser(VCSEL) with large aperture at different temperature, 808nm VCSEL with 500μm emitting diameter are fabricated with Reticular Electrode Structure(RES). Lasing wavelength, optical power and the threshold current are measured by changing the temperature of heat sink. And an output power of 0.42W is achieved at 1.3A at room temperature under continuous wave operation. The central wavelength is 803.32nm, and the full width at half maximum is 0.16nm, the temperature shift is 0.06nm/°, the thermal resistance is 0.098°/mW. The testing results show that 808nm VCSEL with large aperture is good temperature characteristic.

  4. Segmentation of the macular choroid in OCT images acquired at 830nm and 1060nm

    NASA Astrophysics Data System (ADS)

    Lee, Sieun; Beg, Mirza F.; Sarunic, Marinko V.

    2013-06-01

    Retinal imaging with optical coherence tomography (OCT) has rapidly advanced in ophthalmic applications with the broad availability of Fourier domain (FD) technology in commercial systems. The high sensitivity afforded by FD-OCT has enabled imaging of the choroid, a layer of blood vessels serving the outer retina. Improved visualization of the choroid and the choroid-sclera boundary has been investigated using techniques such as enhanced depth imaging (EDI), and also with OCT systems operating in the 1060-nm wavelength range. We report on a comparison of imaging the macular choroid with commercial and prototype OCT systems, and present automated 3D segmentation of the choroid-scleral layer using a graph cut algorithm. The thickness of the choroid is an important measurement to investigate for possible correlation with severity, or possibly early diagnosis, of diseases such as age-related macular degeneration.

  5. Versatile 1 W narrow band 976 nm and 1064 nm light sources

    NASA Astrophysics Data System (ADS)

    Mohrdiek, S.; Pfeiffer, H.-U.; Zibik, E. A.; Sverdlov, B.; Pliska, T.; Lichtenstein, N.

    2011-02-01

    We report on development of novel curved waveguide (CWG) laser devices, where the emission wavelength centered at ~976 nm is stabilized to a 20 dB bandwidth of less than 100 picometer by using fiber Bragg gratings (FBG). Radiation from the curved waveguide laser is coupled using an anamorphic fiber lens into a single mode polarization maintaining fiber containing the FBG, the latter acting as a front reflector. The high power gain chip is based on Oclaro's InGaAs/AlGaAs quantum well laser. Use of the curved waveguide geometry allows to eliminate residual reflections in the optical path of the cavity, which is formed by the rear chip facet and the FBG. It is well known that additional reflections lead to significant deterioration of the spectral and power stability. The devices, assembled in telecom type housings, provide up to 1 W of low-noise and kink-free CW power. In addition pulse operation in nanosecond range is also investigated. The spectral stabilization time to the wavelength of the FBG is limited by the external cavity roundtrip of ~2 ns. A side mode suppression ratio of about 40 dB and higher is achieved for pulsed and CW operation. Results are also presented for a device at 1064 nm. Numerous applications can be envisioned for these devices. For instance devices with high power and ultranarrow spectral bandwidth allow greater flexibility in the choice of parameters for frequency conversion applications. In pulsed mode the device can be used in the special sensing applications where spectral stability is crucial.

  6. Detection limits of 405 nm and 633 nm excited PpIX fluorescence for brain tumor detection during stereotactic biopsy

    NASA Astrophysics Data System (ADS)

    Markwardt, Niklas; Götz, Marcus; Haj-Hosseini, Neda; Hollnburger, Bastian; Sroka, Ronald; Stepp, Herbert; Zelenkov, Petr; Rühm, Adrian

    2016-04-01

    5-aminolevulinic-acid-(5-ALA)-induced protoporphyrin IX (PpIX) fluorescence may be used to improve stereotactic brain tumor biopsies. In this study, the sensitivity of PpIX-based tumor detection has been investigated for two potential excitation wavelengths (405 nm, 633 nm). Using a 200 μm fiber in contact with semi-infinite optical phantoms containing ink and Lipovenös, PpIX detection limits of 4.0 nM and 200 nM (relating to 1 mW excitation power) were determined for 405 nm and 633 nm excitation, respectively. Hence, typical PpIX concentrations in glioblastomas of a few μM should be well detectable with both wavelengths. Additionally, blood layers of selected thicknesses were placed between fiber and phantom. Red excitation was shown to be considerably less affected by blood interference: A 50 μm blood layer, for instance, blocked the 405- nm-excited fluorescence completely, but reduced the 633-nm-excited signal by less than 50%. Ray tracing simulations demonstrated that - without blood layer - the sensitivity advantage of 405 nm rises for decreasing fluorescent volume from 50-fold to a maximum of 100-fold. However, at a tumor volume of 1 mm3, which is a typical biopsy sample size, the 633-nm-excited fluorescence signal is only reduced by about 10%. Further simulations revealed that with increasing fiber-tumor distance, the signal drops faster for 405 nm. This reduces the risk of detecting tumor tissue outside the needle's coverage, but diminishes the overlap between optically and mechanically sampled volumes. While 405 nm generally offers a higher sensitivity, 633 nm is more sensitive to distant tumors and considerably superior in case of blood-covered tumor tissue.

  7. 40nm tunable multi-wavelength fiber laser

    NASA Astrophysics Data System (ADS)

    Jia, Qingsong; Wang, Tianshu; Zhang, Peng; Dong, Keyan; Jiang, Huilin

    2014-12-01

    A Brillouin-Erbium multi-wavelength tunable fiber laser at C-band is demostrated. A 10 km long singlemode fiber(SMF), a 6 m long Erbium-doped fiber, two couplers, a wavelength division multiplexer, a isolator, an optical circulator, a 980nm pump laser and a narrow linewidth tunable laser are included in the structure. A segment of 10 km-long single-mode fiber (SMF) between the two ports of a 1×2 coupler is used as Brillouin gain. Ebiumdoped fiber amplifier (EDFA) consists of a segment of 6m er-doped fiber pumped by 980nm laser dioder . A narrow linewidth tunable laser from 1527 to 1607 nm as Brillouin bump, At the Brillouin pump power of 8mW and the 980 nm pump power of 400 mw, 16 output channels with 0.08 nm spacing and tuning range of 40 nm from 1527 nm to 1567 nm are achieved. We realize the tunable output of wavelength by adjusting the 980 nm pump power and the Brillouin pump wavelength. Stability of the multiwavelength fiber laser is also observed.

  8. 7nm logic optical lithography with OPC-Lite

    NASA Astrophysics Data System (ADS)

    Smayling, Michael C.; Tsujita, Koichiro; Yaegashi, Hidetami; Axelrad, Valery; Nakayama, Ryo; Oyama, Kenichi; Yamauchi, Shohei; Ishii, Hiroyuki; Mikami, Koji

    2015-03-01

    The CMOS logic 22nm node was the last one done with single patterning. It used a highly regular layout style with Gridded Design Rules (GDR). Smaller nodes have required the same regular layout style but with multiple patterning for critical layers. A "line/cut" approach is being used to achieve good pattern fidelity and process margin.[1] As shown in Fig. 1, even with "line" patterns, pitch division will eventually be necessary. For the "cut" pattern, Design-Source-Mask Optimization (DSMO) has been demonstrated to be effective at the 20nm node and below.[2,3,4] Single patterning was found to be suitable down to 16nm, while double patterning extended optical lithography for cuts to the 10-12nm nodes. Design optimization avoided the need for triple patterning. Lines can be patterned with 193nm immersion with no complex OPC. The final line dimensions can be achieved by applying pitch division by two or four.[5] In this study, we extend the scaling using simplified OPC to the 7nm node for critical FEOL and BEOL layers. The test block is a reasonably complex logic function with ~100k gates of combinatorial logic and flip-flops, scaled from previous experiments. Simulation results show that for cuts at 7nm logic dimensions, the gate layer can be done with single patterning whose minimum pitch is 53nm, possibly some of the 1x metal layers can be done with double patterning whose minimum pitch is 53nm, and the contact layer will require triple patterning whose minimum pitch is 68nm. These pitches are less than the resolution limit of ArF NA=1.35 (72nm). However these patterns can be separated by a combination of innovative SMO for less than optical resolution limit and a process trick of hole-repair technique. An example of triple patterning coloring is shown in Fig 3. Fin and local interconnect are created by lines and trims. The number of trim patterns are 3 times (min. pitch=90nm) and twice (min. pitch=120nm), respectively. The small number of masks, large pitches, and

  9. Polarization-dependent aluminum metasurface operating at 450 nm.

    PubMed

    Højlund-Nielsen, Emil; Zhu, Xiaolong; Carstensen, Marcus S; Sørensen, Michael K; Vannahme, Christoph; Asger Mortensen, N; Kristensen, Anders

    2015-11-01

    We report on a polarization-dependent plasmonic aluminum-based high-density metasurface operating at blue wavelengths. The fabricated sub-wavelength structures, tailored in size and geometry, possess strong, localized, plasmonic resonances able to control linear polarization. Best performance is achieved by rotating an elongated rectangular structure of length 180 nm and width 110 nm inside a square lattice of period 250 nm. In the case of 45 degrees rotation of the structure with respect to the lattice, the normal-incidence reflectance drops around the resonance wavelength of 457 nm from about 60 percent to below 2 percent. PMID:26561151

  10. Generation and use of high power 213 nm and 266 nm laser radiation and tunable 210-400 nm laser radiation with BBO crystal matrix array

    DOEpatents

    Gruen, Dieter M.

    2000-01-01

    A 213 nm laser beam is capable of single photon ablative photodecomposition for the removal of a polymer or biological material substrate. Breaking the molecular bonds and displacing the molecules away from the substrate in a very short time period results in most of the laser photon energy being carried away by the displaced molecules, thus minimizing thermal damage to the substrate. The incident laser beam may be unfocussed and is preferably produced by quintupling the 1064 nm radiation from a Nd:YAG solid state laser, i.e., at 213 nm. In one application, the 213 nm laser beam is expanded in cross section and directed through a plurality of small beta barium borate (BBO) crystals for increasing the energy per photon of the laser radiation directed onto the substrate. The BBO crystals are arranged in a crystal matrix array to provide a large laser beam transmission area capable of accommodating high energy laser radiation without damaging the BBO crystals. The BBO crystal matrix array may also be used with 266 nm laser radiation for carrying out single or multi photon ablative photodecomposition. The BBO crystal matrix array may also be used in an optical parametric oscillator mode to generate high power tunable laser radiation in the range of 210-400 nm.

  11. Flash-lamp pumped Pr:YAP laser operated at wavelengths of 747 nm and 662 nm

    NASA Astrophysics Data System (ADS)

    Fibrich, Martin; Jelínková, Helena; Šulc, Jan; Nejezchleb, Karel; Škoda, Václav

    2009-02-01

    Successful room-temperature generation of Pr:YAP laser radiation at wavelengths of 747 nm and 662 nm was demonstrated. A flash-lamp pumped Pr:YAP laser was operated in free-running pulsed regime at room temperature. Permanent laser action was reached by means of a special UV color glass plate filter placed directly into the laser cavity. The maximum output energy and pulse length reached at wavelengths of 747 nm and 662 nm were 102 mJ, 92 μs and 6.1 mJ, 47.5 μs, respectively. The laser beam parameter M2 ~ 1.5 was measured when the 662 nm wavelength was generated. In the case of 747 nm wavelength generation, M2 ~ 1.2 was reached with a diaphragm inside the resonator. For different pumped energy values, the line shape and linewidth remained stable for both cases.

  12. 1319 nm and 1356 nm dual-wavelength operation of diode-side-pumped Nd:YAG laser

    NASA Astrophysics Data System (ADS)

    Chen, Ming; Wang, Zhi-chao; Zhang, Shen-jin; Yang, Feng; Zhang, Feng-feng; Yuan, Lei; He, Miao; Li, Jia-jia; Zhang, Xiao-wen; Zong, Nan; Wang, Zhi-min; Bo, Yong; Peng, Qin-jun; Cui, Da-fu; Xu, Zu-yan

    2016-05-01

    We report the first demonstration on a diode-side-pumped quasi continuous wave (QCW) dual-wavelength Nd:YAG laser operating at 1319 nm and 1356 nm. The resonator adopts symmetrical L-shaped flat-flat structure working in a thermally near unstable cavity. By precise coating on the cavity mirrors, the simultaneous oscillation at 1319 nm and 1356 nm is delivered. A maximum dual-wavelength output power of 9.4 W is obtained. The beam quality factor M2 is measured to be 1.9.

  13. Evaluation of dental pulp repair using low level laser therapy (688 nm and 785 nm) morphologic study in capuchin monkeys

    NASA Astrophysics Data System (ADS)

    Pretel, H.; Oliveira, J. A.; Lizarelli, R. F. Z.; Ramalho, L. T. O.

    2009-02-01

    The aim of this study was to evaluate the hypothesis that low-level laser therapy (LLLT) 688 nm and 785 nm accelerate dentin barrier formation and repair process after traumatic pulp exposure. The sample consisted of 45 premolars of capuchin monkeys (Cebus apella) with pulp exposure Class V cavities. All premolars were treated with calcium hydroxide (Ca(OH)2), divided in groups of 15 teeth each, and analyzed on 7th, 25th, and 60th day. Group GI - only Ca(OH)2, GII - laser 688 nm, and GIII - laser 785 nm. Laser beam was used in single and punctual dose with the parameters: continuous, 688 nm and 785 nm wavelength, tip's area of 0.00785 cm2, power 50 mW, application time 20 s, dose 255 J/cm2, energy 2 J. Teeth were capped with Ca(OH)2, Ca(OH)2 cement and restored with amalgam. All groups presented pulp repair. On 25th day the thickness of the formed dentin barrier was different between the groups GI and GII (p < 0.05) and between groups GI and GIII (p < 0.01). On 60th day there was difference between GI and GIII (p < 0.01). It may be concluded that, LLLT 688 nm and 785 nm accelerated dentin barrier formation and consequently pulp repair process, with best results using infrared laser 785 nm.

  14. Demonstration of miniaturized 20mW CW 280nm and 266nm solid-state UV laser sources

    NASA Astrophysics Data System (ADS)

    Landru, Nicolas; Georges, Thierry; Beaurepaire, Julien; Le Guen, Bruno; Le Bail, Guy

    2015-02-01

    Visible 561 nm and 532 nm laser emissions from 14-mm long DPSS monolithic cavities are frequency converted to deep UV 280 nm and 266 nm in 16-mm long monolithic external cavities. Wavelength conversion is fully insensitive to mechanical vibrations and the whole UV laser sources fit in a miniaturized housing. More than 20 mW deep UV laser emission is demonstrated with high power stability, low noise and good beam quality. Aging tests are in progress but long lifetimes are expected thanks to the cavity design. Protein detection and deep UV resonant Raman spectroscopy are applications that could benefit from these laser sources.

  15. Model-based scattering bars implementation for 65nm and 45nm nodes using IML technology

    NASA Astrophysics Data System (ADS)

    Hsu, Michael; Van Den Broeke, Doug; Laidig, Tom; Wampler, Kurt E.; Hollerbach, Uwe; Socha, Robert; Chen, J. F.; Hsu, Stephen; Shi, Xuelong

    2005-06-01

    Scattering Bars (SB) OPC, together with optimized illumination, is no doubt one of the critical enablers for low k1 lithography manufacturing. The manufacturing implementation of SB so far has been mainly based on rule-based approach. While this has been working well, a more effective model-based approach is much more desired lithographically for manufacturing at 65nm and 45nm nodes. This is necessary to ensure sufficient process margin using hyper NA for patterning random IC design. In our model-based SB (M-SB) OPC implementation, we have based on the patented IML Technology from ASML MaskTools. In this report, we use both dark field contact hole and clear field poly gate mask to demonstrate this implementation methodology. It is also quite applicable for dark field trench masks, such as local interconnect mask with damascene metal. For our full-chip implementation flow, the first step is to determine the critical design area and then to proceed with NA and illumination optimization. We show that, using LithoCruiser, we are able to select the best NA in combination with optimum illumination via a Diffraction Optical Element (DOE). The decision to use a custom DOE or one from the available DOE library from ASML can be made based on predicted process performance and cost effectiveness. With optimized illumination, it is now possible to construct an interference map for the full-chip mask pattern. Utilizing the interference map, M-SB OPC is generated. Next, model OPC can be applied with the presence of M-SB for the entire chip. It is important to note here, that from our experience, the model OPC must be calibrated with the presence of SB in order to achieve the desired accuracy. We report the full-chip processing benchmark using MaskWeaver to apply both M-SB and model OPC. For actual patterning performance, we have verified the full chip OPC treatment using SLiC, a DFM tool from Cadence. This implementation methodology can be applied to binary chrome mask

  16. Synthesis and electrochemistry of 6 nm ferrocenated indium-tin oxide nanoparticles.

    PubMed

    Roberts, Joseph J P; Vuong, Kim T; Murray, Royce W

    2013-01-01

    Indium-tin oxide (ITO) nanoparticles, 6.1 ± 0.8 nm in diameter, were synthesized using a hot injection method. After reaction with 3-aminopropyldimethylethoxysilane to replace the initial oleylamine and oleic acid capping ligands, the aminated nanoparticles were rendered electroactive by functionalization with ferrocenoyl chloride. The nanoparticle color changed from blue-green to light brown, and the nanoparticles became more soluble in polar solvents, notably acetonitrile. The nanoparticle diffusion coefficient (D = 1.0 × 10(-6) cm(2)/s) and effective ferrocene concentration (C = 0.60 mM) in acetonitrile solutions were determined using ratios of DC and D(1/2)C data measured by microdisk voltammetry and chronoamperometry. The D result compares favorably to an Einstein-Stokes estimate (2.1 × 10(-6) cm(2)/s), assuming an 8 nm hydrodynamic diameter in acetonitrile (6 nm for the ITO core plus 2 nm for the ligand shell). The ferrocene concentration result is lower than anticipated (ca. 1.60 mM) based on a potentiometric titration of the ferrocene sites with Cu(II) in acetonitrile. Cyclic voltammetric data indicate tendency of the ferrocenated nanoparticles to adsorb on the Pt working electrode. PMID:23267676

  17. Electric Field-Assisted Photochemical Water Splitting Should Operate with 287 nm Light.

    PubMed

    Bachler, Vinzenz; Gärtner, Wolfgang

    2016-05-01

    The major photoreaction of water is the homolytic splitting of one O-H bond starting from the 1(1) B1 excited state (λmax = 167 nm). This reaction produces H• and •OH radicals. The combination of two H• atoms leads to the potential energy carrier dihydrogen. However, the energy required to obtain the photoreactive 1(1) B1 electronic state is about 7.4 eV, which cannot be effectively provided by solar radiation. The sun light spectrum on earth comprises the visible and ultraviolet region, but shows vanishing intensity near 7 eV (177.1 nm). This work provides theoretical evidence that the photoreactive 1(1) B1 state of water can be shifted into the ultraviolet (UV-B) light region (≈287 nm) by including explicitly an electric field in the calculations of the water absorption spectrum. To accomplish such bathochromic shift, a large field strength of 3.08 VÅ(-1) is required. The field-dependent excitation energies were calculated by applying the symmetry-adapted cluster configuration interaction (SAC-CI) procedure. Based on this theoretical analysis, we propose that photochemical water splitting can be accomplished by means of 287 nm light provided the water molecule is favorably oriented by an external electric field and is subsequently activated by a reversal of the field orientation. PMID:26876336

  18. Electron beam inspection of 16nm HP node EUV masks

    NASA Astrophysics Data System (ADS)

    Shimomura, Takeya; Narukawa, Shogo; Abe, Tsukasa; Takikawa, Tadahiko; Hayashi, Naoya; Wang, Fei; Ma, Long; Lin, Chia-Wen; Zhao, Yan; Kuan, Chiyan; Jau, Jack

    2012-11-01

    EUV lithography (EUVL) is the most promising solution for 16nm HP node semiconductor device manufacturing and beyond. The fabrication of defect free EUV mask is one of the most challenging roadblocks to insert EUVL into high volume manufacturing (HVM). To fabricate and assure the defect free EUV masks, electron beam inspection (EBI) tool will be likely the necessary tool since optical mask inspection systems using 193nm and 199nm light are reaching a practical resolution limit around 16nm HP node EUV mask. For production use of EBI, several challenges and potential issues are expected. Firstly, required defect detection sensitivity is quite high. According to ITRS roadmap updated in 2011, the smallest defect size needed to detect is about 18nm for 15nm NAND Flash HP node EUV mask. Secondly, small pixel size is likely required to obtain the high sensitivity. Thus, it might damage Ru capped Mo/Si multilayer due to accumulated high density electron beam bombardments. It also has potential of elevation of nuisance defects and reduction of throughput. These challenges must be solved before inserting EBI system into EUV mask HVM line. In this paper, we share our initial inspection results for 16nm HP node EUV mask (64nm HP absorber pattern on the EUV mask) using an EBI system eXplore® 5400 developed by Hermes Microvision, Inc. (HMI). In particularly, defect detection sensitivity, inspectability and damage to EUV mask were assessed. As conclusions, we found that the EBI system has capability to capture 16nm defects on 64nm absorber pattern EUV mask, satisfying the sensitivity requirement of 15nm NAND Flash HP node EUV mask. Furthermore, we confirmed there is no significant damage to susceptible Ru capped Mo/Si multilayer. We also identified that low throughput and high nuisance defect rate are critical challenges needed to address for the 16nm HP node EUV mask inspection. The high nuisance defect rate could be generated by poor LWR and stitching errors during EB writing

  19. Next-generation 193-nm laser for sub-100-nm lithography

    NASA Astrophysics Data System (ADS)

    Duffey, Thomas P.; Blumenstock, Gerry M.; Fleurov, Vladimir B.; Pan, Xiaojiang; Newman, Peter C.; Glatzel, Holger; Watson, Tom A.; Erxmeyer, J.; Kuschnereit, Ralf; Weigl, Bernhard

    2001-09-01

    The next generation 193 nm (ArF) laser has been designed and developed for high-volume production lithography. The NanoLithTM 7000, offering 20 Watts average output power at 4 kHz repetition rates is designed to support the highest exposure tool scan speeds for maximum productivity and wafer throughput. Fundamental design changes made to the laser core technologies are described. These advancements in core technology support the delivery of highly line-narrowed light with

  20. Scattering matrices of martian dust analogs at 488 nm and 647 nm

    NASA Astrophysics Data System (ADS)

    Dabrowska, Dominika D.; Muñoz, Olga; Moreno, Fernando; Ramos, José L.; Martínez-Frías, Jesús; Wurm, Gerhard

    2015-04-01

    We present measurements of the complete scattering matrix as a function of the scattering angle of five martian dust analogs, namely montmorillonite, two palagonite (JSC-1) samples, basalt, and calcite. The measurements are performed at 488 and 647 nm, covering the scattering angle range from 3° to 177°. The experimental scattering matrices are compared with results of Lorenz-Mie calculations performed for the same size distributions and refractive indices as our analog samples. As expected, we find that scattering matrices of realistic polydispersions of dust particles cannot be replaced by such calculated matrices. In contrast, the measured phase functions for our martian dust analogs may be considered a good approximation for martian dust at the studied wavelengths. Further, because of the sensitivity of polarimetry to particle microphysics, spectro-polarimetric observations from the martian surface appear to be a powerful diagnostic tool to infer the composition of the dust in the martian atmosphere. To facilitate the use of the experimental matrices for multiple-scattering calculations with polarization included, we compute the corresponding synthetic scattering matrices based on the measurements and defined in the full angle range from 0° to 180°.

  1. Tailoring 10 nm scale suspended graphene junctions and quantum dots.

    PubMed

    Tayari, Vahid; McRae, Andrew C; Yiğen, Serap; Island, Joshua O; Porter, James M; Champagne, Alexandre R

    2015-01-14

    The possibility to make 10 nm scale, and low-disorder, suspended graphene devices would open up many possibilities to study and make use of strongly coupled quantum electronics, quantum mechanics, and optics. We present a versatile method, based on the electromigration of gold-on-graphene bow-tie bridges, to fabricate low-disorder suspended graphene junctions and quantum dots with lengths ranging from 6 nm up to 55 nm. We control the length of the junctions, and shape of their gold contacts by adjusting the power at which the electromigration process is allowed to avalanche. Using carefully engineered gold contacts and a nonuniform downward electrostatic force, we can controllably tear the width of suspended graphene channels from over 100 nm down to 27 nm. We demonstrate that this lateral confinement creates high-quality suspended quantum dots. This fabrication method could be extended to other two-dimensional materials. PMID:25490053

  2. High-efficency stable 213-nm generation for LASIK application

    NASA Astrophysics Data System (ADS)

    Wang, Zhenglin; Alameh, Kamal; Zheng, Rong

    2005-01-01

    213nm Solid-state laser technology provides an alternative method to replace toxic excimer laser in LASIK system. In this paper, we report a compact fifth harmonic generation system to generate high pulse energy 213nm laser from Q-switched Nd:YAG laser for LASIK application based on three stages harmonic generation procedures. A novel crystal housing was specifically designed to hold the three crystals with each crystal has independent, precise angular adjustment structure and automatic tuning control. The crystal temperature is well maintained at ~130°C to improve harmonic generation stability and crystal operation lifetime. An output pulse energy 35mJ is obtained at 213nm, corresponding to total conversion efficiency ~10% from 1064nm pump laser. In system verification tests, the 213nm output power drops less than 5% after 5 millions pulse shots and no significant damage appears in the crystals.

  3. Methods to achieve sub-100-nm contact hole lithography

    NASA Astrophysics Data System (ADS)

    Lindsay, Tracy K.; Kavanagh, Robert J.; Pohlers, Gerd; Kanno, Takafumi; Bae, Young C.; Barclay, George G.; Kanagasabapathy, Subbareddy; Mattia, Joseph

    2003-06-01

    There are numerous methods being explored by lithographers to achieve contact holes below 100nm. Regarding optical impact on contact hole imaging, very high numerical aperture tools are becoming available at 193nm (as high as 0.9) and various optical extension techniques such as assist features, focus drilling, phase shift masks, and off-axis illumination are being employed to improve the aerial image. In this paper, the impact of the ArF photoresist is investigated. Polymers capable of thermal reflow of larger (~140nm) to smaller (90nm and below) contact holes are presented. Improved materials to achieve the properties necessary for good contact hole imaging for standard single layer resist (SLR) processing are also discussed. State-of-the-art ultra-thin resists (UTR) for contact holes and 193nm bi-layer resist systems are also studied as viable techniques to achieving very small contact holes.

  4. Applications of the 308-nm excimer laser in dermatology

    NASA Astrophysics Data System (ADS)

    Farkas, A.; Kemeny, L.

    2006-05-01

    Excimer lasers contain a mixture of a noble inert gas and a halogen, which form excited dimers only in the activated state. High-energy current is used to produce these dimers, which have a very short lifetime, and after their fast dissociation they release the excitation energy through ultraviolet photons. The application of these lasers proved to be successful in medicine, including the field of ophthalmology, cardiology, angiology, dentistry, orthopaedics, and, in recent years, dermatology. For medical purposes, the 193-nm argon fluoride, the 248-nm krypton fluoride, the 351-nm xenon fluoride, and the 308-nm xenon chloride lasers are used. Recently, the 308-nm xenon chloride laser has gained much attention as a very effective treatment modality in dermatological disorders. It was successfully utilized in psoriasis; later, it proved to be useful in handling other lightsensitive skin disorders and even in the treatment of allergic rhinitis. This review summarizes the possible applications of this promising tool in dermatology.

  5. Core level photoionization on free sub-10-nm nanoparticles using synchrotron radiation

    SciTech Connect

    Meinen, Jan; Leisner, Thomas; Khasminskaya, Svetlana; Eritt, Markus; Antonsson, Egill; Langer, Burkhard; Ruehl, Eckart

    2010-08-15

    A novel instrument is presented, which permits studies on singly charged free nanoparticles in the diameter range from 1 to 30 nm using synchrotron radiation in the soft x-ray regime. It consists of a high pressure nanoparticle source, a high efficiency nanoparticle beam inlet, and an electron time-of-flight spectrometer suitable for probing surface and bulk properties of free, levitated nanoparticles. We show results from x-ray photoelectron spectroscopy study near the Si L{sub 3,2}-edge on 8.2 nm SiO{sub 2} particles prepared in a nanoparticle beam. The possible use of this apparatus regarding chemical reactions on the surface of nanometer-sized particles is highlighted. This approach has the potential to be exploited for process studies on heterogeneous atmospheric chemistry.

  6. Design of 200-nm, 170-nm, and 140-nm DUV contact sweeper high-transmission attenuating phase-shift mask: II. Experimental results

    NASA Astrophysics Data System (ADS)

    Socha, Robert J.; Shi, Xuelong; Holman, Ken C.; Dusa, Mircea V.; Conley, Will; Petersen, John S.; Chen, J. Fung; Laidig, Thomas L.; Wampler, Kurt E.; Caldwell, Roger F.; Chu, M. C.; Su, Chung Jen; Hung, Kuei-Chun; Chen, C.; Wang, F.; Le, C.; Pierrat, Christophe; Su, Bo

    1999-07-01

    Experiments for 140nm and 160nm contacts were optimized through simulation on an 18 percent transmitting phase shift mask for KrF lithography. A transmission of 18 percent is shown to have the most linear aerial image behavior through focus. The simulations were run using a primitive positive photoresist model in order to predict trends in resolution and to predict when side lobes begin printing. Experiments show that the 140nm and 160nm contact holes resolve without side lobe printing through focus and through exposure. Reticle SEMs verify that a ternary contact hole mask is capable of manufacture. By adding both opaque and clear sub- resolution assist features, the experiments show contacts as small as 140nm resolve with 0.50 micrometers focus latitude with 10 percent exposure latitude through pitch. Cross sectional SEMs verify that contact holes are larger due to the addition of zero order light as suggested by theory and show that side lobes begin to print. Experiments also prove that NA has the largest impact on resolution and exposure latitude and that (sigma) has the largest impact on depth of focus.

  7. Gain-switched 311-nm Ti:Sapphire laser might be a potential treatment modality for atopic dermatitis.

    PubMed

    Choi, Sun Young; Oh, Chang Taek; Kwon, Tae-Rin; Kwon, Hyun Jung; Choi, Eun Ja; Jang, Yu-Jin; Kim, Hye Sung; Chu, Hong; Mun, Seog Kyun; Kim, Myeung Nam; Kim, Beom Joon

    2016-09-01

    Phototherapy with 311-nm narrowband-UVB (NBUVB) is an effective adjuvant treatment modality for atopic dermatitis (AD). In this study, we evaluated the therapeutic effect of the newly developed gain-switched 311-nm Ti:Sapphire laser device using a NC/Nga mouse AD model. A total number of 50 mice were used in this study. Atopic dermatitis (AD) was induced in mice by exposure to Dermatophagoides farina. These, NC/Nga mice were then treated with conventional 311-nm NBUVB or the newly developed gain-switched 311-nm Ti:Sapphire laser. The clinical features, dermatitis severity scores, and scratching behavior were assessed. In addition, serologic analyses including inflammatory cytokines and histological analyses were performed. Gain-switched 311-nm Ti:Sapphire laser improved the AD-like skin lesions, severity, and symptoms of AD in the NC/Nga mouse model. This new laser also modulated the immune response found in the AD model, including hyper-IgE, upregulated Th2 cytokines, and the Th2-mediated allergic inflammatory reaction. Gain-switched 311-nm Ti:Sapphire laser shows therapeutic promise via an immune-modulation mechanism in an AD mouse model. These data suggest that gain-switched 311-nm Ti:Sapphire laser may be useful as a targeted phototherapy modality for AD. PMID:27394442

  8. Ultraviolet absorption cross sections of Cl sub 2 O sub 2 between 210 and 410 nm

    SciTech Connect

    Burkholder, J.B.; Orlando, J.J.; Howard, C.J. Univ. of Colorado, Boulder )

    1990-01-25

    The ultraviolet and infrared absorption cross sections of Cl{sub 2}O{sub 2} have been measured. The transient Cl{sub 2}O{sub 2} molecule was produced by using the gas-phase reaction ClO + ClO + M {yields} Cl{sub 2}O{sub 2} + M. Three independent ClO radical source reactions were used in this study: Cl + O{sub 3}, Cl + Cl{sub 2}O, and Cl + OClO. The Cl{sub 2}O{sub 2} UV absorption spectrum was recorded over the range 200-450 nm with a diode array spectrometer over the temperature range 205-250 K. The Cl{sub 2}O{sub 2} infrared absorption spectrum was recorded with a high-resolution Fourier transform spectrometer over the range 500-2,000 cm{sup {minus}1}. Both spectrometers were optically coupled to a fast flow multipass absorption cell. The UV absorption spectrum of Cl{sub 2}O{sub 2} is a structureless continuum with a peak at 245 nm. The measurable absorption extends out to 410 nm. The UV absorption cross section at the peak of the spectrum, 245 nm, was measured to be (6.5{sub {minus}0.5}{sup +0.8}) {times} 10{sup {minus}18} cm{sup 2}. Infrared absorption features centered at 560, 653, and 750 cm{sup {minus}1} have been assigned to the Cl{sub 2}O{sub 2} molecule. The present results are compared with other reported UV and IR measurements and the sources of discrepancies are discussed. The role of Cl{sub 2}O{sub 2} in atmospheric chemistry and in particular the Antarctic ozone hole are discussed.

  9. Response of Cloud Condensation Nuclei (> 50 nm) to changes in ion-nucleation

    NASA Astrophysics Data System (ADS)

    Pedersen, J. O.; Enghoff, M. B.; Svensmark, H.

    2012-12-01

    The role of ionization in the formation of clouds and aerosols has been debated for many years. A body of evidence exists that correlates cloud properties to galactic cosmic ray ionization; however these results are still contested. In recent years experimental evidence has also been produced showing that ionization can promote the nucleation of small aerosols at atmospheric conditions. The experiments showed that an increase in ionization leads to an increase in the formation of ultrafine aerosols (~3 nm), but in the real atmosphere such small particles have to grow by coagulation and condensation to become cloud condensation nuclei (CCN) in order to have an effect on clouds. However, numerical studies predict that variations in the count of ultra-fine aerosols will lead only to an insignificant change in the count of CCN. This is due to 1) the competition between the additional ultra-fine aerosols for the limited supply of condensable gases leading to a slower growth and 2) the increased loss rates of the additional particles during the longer growth-time. We investigated the growth of aerosols to CCN sizes using an 8 m3 reaction chamber made from electro-polished stainless steel. One side was fitted with a Teflon foil to allow ultraviolet light to illuminate the chamber, which was continuously flushed with dry purified air. Variable concentrations of water vapor, ozone, and sulfur dioxide could be added to the chamber. UV-lamps initiated photochemistry producing sulfuric acid. Ionization could be enhanced with two Cs-137 gamma sources (30 MBq), mounted on each side of the chamber. Figure 1 shows the evolution of the aerosols, following a nucleation event induced by the gamma sources. Previous to the event the aerosols were in steady state. Each curve represents a size bin: 3-10 nm (dark purple), 10-20 nm (purple), 20-30 nm (blue), 30-40 nm (light blue), 40-50 nm (green), 50-60 nm (yellow), and 60-68 nm (red). Black curves show a ~1 hour smoothing. The initial

  10. Transport of triplet excitons along continuous 100 nm polyfluorene chains

    SciTech Connect

    Xi, Liang; Bird, Matthew; Mauro, Gina; Asaoka, Sadayuki; Cook, Andrew R.; Chen, Hung -Cheng; Miller, John R.

    2014-12-03

    Triplet excitons created in poly-2,7-(9,9-dihexyl)fluorene (pF) chains with end trap groups in solution are efficiently transported to and captured by the end groups. The triplets explore the entire lengths of the chains, even for ~100 nm long chains enabling determination of the completeness of end capping. The results show that the chains continuous: they may contain transient barriers or traps, such as those from fluctuations of dihedral angles, but are free of major defects that stop motion of the triplets. Quantitative determinations are aided by the addition of a strong electron donor, TMPD, which removes absorption bands of the end-trapped triplets. For chains having at least one end trap, triplet capture is quantitative on the 1 µs timescale imposed by the use of the donor. Fractions of chains having no end traps were 0.15 for pF samples with anthraquinone (AQ) end traps and 0.063 with naphthylimide (NI) end traps. These determinations agreed with measurements by NMR for short (<40 polymer repeat units (PRU)) chains, where NMR determinations are accurate. The results find no evidence for traps or barriers to transport of triplets, and places limits on the possible presence of defects as impenetrable barriers to less than one per 300 PRU. The present results present a paradigm different from the current consensus, derived from observations of singlet excitons, that conjugated chains are divided into “segments,” perhaps by some kind of defects. For the present pF chains, the segmentation either does not apply to triplet excitons or is transient so that the defects are healed or surmounted in times much shorter than 1 µs. Triplets on chains without end trap groups transfer to chains with end traps on a slower time scale. Rate constants for these bimolecular triplet transfer reactions were found to increase with the length of the accepting chain, as did rate constants for triplet transfer to the chains from small molecules like biphenyl. As a result, a

  11. Transport of triplet excitons along continuous 100 nm polyfluorene chains

    DOE PAGESBeta

    Xi, Liang; Bird, Matthew; Mauro, Gina; Asaoka, Sadayuki; Cook, Andrew R.; Chen, Hung -Cheng; Miller, John R.

    2014-12-03

    Triplet excitons created in poly-2,7-(9,9-dihexyl)fluorene (pF) chains with end trap groups in solution are efficiently transported to and captured by the end groups. The triplets explore the entire lengths of the chains, even for ~100 nm long chains enabling determination of the completeness of end capping. The results show that the chains continuous: they may contain transient barriers or traps, such as those from fluctuations of dihedral angles, but are free of major defects that stop motion of the triplets. Quantitative determinations are aided by the addition of a strong electron donor, TMPD, which removes absorption bands of the end-trappedmore » triplets. For chains having at least one end trap, triplet capture is quantitative on the 1 µs timescale imposed by the use of the donor. Fractions of chains having no end traps were 0.15 for pF samples with anthraquinone (AQ) end traps and 0.063 with naphthylimide (NI) end traps. These determinations agreed with measurements by NMR for short (<40 polymer repeat units (PRU)) chains, where NMR determinations are accurate. The results find no evidence for traps or barriers to transport of triplets, and places limits on the possible presence of defects as impenetrable barriers to less than one per 300 PRU. The present results present a paradigm different from the current consensus, derived from observations of singlet excitons, that conjugated chains are divided into “segments,” perhaps by some kind of defects. For the present pF chains, the segmentation either does not apply to triplet excitons or is transient so that the defects are healed or surmounted in times much shorter than 1 µs. Triplets on chains without end trap groups transfer to chains with end traps on a slower time scale. Rate constants for these bimolecular triplet transfer reactions were found to increase with the length of the accepting chain, as did rate constants for triplet transfer to the chains from small molecules like biphenyl. As a

  12. Wavelength dependence on the forensic analysis of glass by nanosecond 266 nm and 1064 nm laser induced breakdown spectroscopy

    SciTech Connect

    Cahoon, Erica M.; Almirall, Jose R.

    2010-05-01

    Laser induced breakdown spectroscopy can be used for the chemical characterization of glass to provide evidence of an association between a fragment found at a crime scene to a source of glass of known origin. Two different laser irradiances, 266 nm and 1064 nm, were used to conduct qualitative and quantitative analysis of glass standards. Single-pulse and double-pulse configurations and lens-to-sample-distance settings were optimized to yield the best laser-glass coupling. Laser energy and acquisition timing delays were also optimized to result in the highest signal-to-noise ratio corresponding to the highest precision and accuracy. The crater morphology was examined and the mass removed was calculated for both the 266 nm and 1064 nm irradiations. The analytical figures of merit suggest that the 266 nm and 1064 nm wavelengths are capable of good performance for the forensic chemical characterization of glass. The results presented here suggest that the 266 nm laser produces a better laser-glass matrix coupling, resulting in a better stoichiometric representation of the glass sample. The 266 nm irradiance is therefore recommended for the forensic analysis and comparison of glass samples.

  13. 1064 nm laser emission of highly doped Nd: Yttrium aluminum garnet under 885 nm diode laser pumping

    NASA Astrophysics Data System (ADS)

    Lupei, V.; Pavel, N.; Taira, T.

    2002-06-01

    Highly efficient 1064 nm continuous-wave laser emission under 885 nm diode pumping in concentrated Nd: Yttrium aluminum garnet (YAG) crystals (up to 3.5 at. % Nd) and ceramics (up to 3.8 at. % Nd) is reported. A highly doped (2.4 at. %) Nd:YAG laser, passively Q switched by a Cr4+:YAG saturable absorber, is demonstrated.

  14. Oxidative hemoglobin reactions: Applications to drug metabolism.

    PubMed

    Spolitak, Tatyana; Hollenberg, Paul F; Ballou, David P

    2016-06-15

    Hb is a protein with multiple functions, acting as an O2 transport protein, and having peroxidase and oxidase activities with xenobiotics that lead to substrate radicals. However, there is a lack of evidence for intermediates involved in these reactions of Hb with redox-active compounds, including those with xenobiotics such as drugs, chemical carcinogens, and sulfides. In particular, questions exist as to what intermediates participate in reactions of either metHb or oxyHb with sulfides. The studies presented here elaborate kinetics and intermediates involved in the reactions of Hb with oxidants (H2O2 and mCPBA), and they demonstrate the formation of high valent intermediates, providing insights into mechanistic issues of sulfur and drug oxidations. Overall, we propose generalized mechanisms that include peroxidatic reactions using H2O2 generated from the autooxidation of oxyHb, with involvement of substrate radicals in reactions of Hb with oxidizable drugs such as metyrapone or 2,4-dinitrophenylhydrazine and with sulfides. We identify ferryl intermediates (with a Soret band at 407 nm) in oxidative reactions with all of the above-mentioned reactions. These spectral properties are consistent with a protonated ferryl heme, such as Cpd II or Cpd ES-like species (Spolitak et al., JIB, 2006, 100, 2034-2044). Mechanism(s) of Hb oxidative reactions are discussed. PMID:27091316

  15. Modeling the distributed gain of single--(1050 or 1410 nm) and dual-wavelength--(800 + 1050 nm or 800 + 1410 nm) pumped thulium-doped fiber amplifiers.

    PubMed

    Floridia, Claudio; Carvalho, M T; Lüthi, S R; Gomes, A S L

    2004-09-01

    The distributed gain of single- and dual-wavelength-pumped thulium-doped fiber amplifiers is modeled. The excellent agreement between the model and coherent optical frequency domain reflectometry measurements enables us to estimate intrinsic loss, branching ratios of fluorescence originating from the 3H4 level, and cross sections of upconversion pumping at 1050 and 1410 nm for the Tm3+ ions in the fiber. With the branching ratios obtained it is possible to describe induced signal absorption when pumping at 800 nm. PMID:15455754

  16. Partially Oxidized Sub-10 nm MnO Nanocrystals with High Activity for Water Oxidation Catalysis

    PubMed Central

    Jin, Kyoungsuk; Chu, Arim; Park, Jimin; Jeong, Donghyuk; Jerng, Sung Eun; Sim, Uk; Jeong, Hui-Yun; Lee, Chan Woo; Park, Yong-Sun; Yang, Ki Dong; Kumar Pradhan, Gajendra; Kim, Donghun; Sung, Nark-Eon; Hee Kim, Sun; Nam, Ki Tae

    2015-01-01

    The oxygen evolution reaction (OER) is considered a major bottleneck in the overall water electrolysis process. In this work, highly active manganese oxide nano-catalysts were synthesized via hot injection. Facile surface treatment generated Mn(III) species on monodisperse 10 nm MnO nanocrystals (NCs). Size dependency of MnO NCs on OER activity was also investigated. Surprisingly, the partially oxidized MnO NCs only required 530 mV @ 5 mA cm−2 under near neutral conditions. PMID:25998696

  17. Partially Oxidized Sub-10 nm MnO Nanocrystals with High Activity for Water Oxidation Catalysis

    NASA Astrophysics Data System (ADS)

    Jin, Kyoungsuk; Chu, Arim; Park, Jimin; Jeong, Donghyuk; Jerng, Sung Eun; Sim, Uk; Jeong, Hui-Yun; Lee, Chan Woo; Park, Yong-Sun; Yang, Ki Dong; Kumar Pradhan, Gajendra; Kim, Donghun; Sung, Nark-Eon; Hee Kim, Sun; Nam, Ki Tae

    2015-05-01

    The oxygen evolution reaction (OER) is considered a major bottleneck in the overall water electrolysis process. In this work, highly active manganese oxide nano-catalysts were synthesized via hot injection. Facile surface treatment generated Mn(III) species on monodisperse 10 nm MnO nanocrystals (NCs). Size dependency of MnO NCs on OER activity was also investigated. Surprisingly, the partially oxidized MnO NCs only required 530 mV @ 5 mA cm-2 under near neutral conditions.

  18. induced by 1,540-nm laser excitation

    NASA Astrophysics Data System (ADS)

    Zheng, J.; Wang, X. F.; He, W. Y.; Bu, Y. Y.; Yan, X. H.

    2014-06-01

    The multi-photon ultraviolet upconversion emission properties and synergistic effect are investigated in BaSr2Y6O12:Er3+ phosphor. The deep-ultraviolet emissions centered at 274, 297 and 324-nm are observed under the 1,540-nm excitation, which results from a seven-, six- and six-photon upconversion process, respectively. A synergistic effect is found, which shows that the red emission intensity under 351- and 1,540-nm dual excitation is 4.7 % time stronger than the sum of red emission intensities under the 351 and 1,540-nm single excitation. This phenomenon is attributed to the 4I13/2 and 4I11/2 levels of Er3+ from non-radiative transition process under the 351-nm excitation are excited again to 4F9/2 level by absorbing 1,540-nm photon in the 351- and 1,540-nm dual-excitation process.

  19. The Glyoxal Clock Reaction

    ERIC Educational Resources Information Center

    Ealy, Julie B.; Negron, Alexandra Rodriguez; Stephens, Jessica; Stauffer, Rebecca; Furrow, Stanley D.

    2007-01-01

    Research on the glyoxal clock reaction has led to adaptation of the clock reaction to a general chemistry experiment. This particular reaction is just one of many that used formaldehyde in the past. The kinetics of the glyoxal clock makes the reaction suitable as a general chemistry lab using a Calculator Based Laboratory (CBL) or a LabPro. The…

  20. Study of 193-nm resist degradation under various etch chemistries

    NASA Astrophysics Data System (ADS)

    Bazin, Arnaud; May, Michael; Pargon, Erwine; Mortini, Benedicte; Joubert, Olivier

    2007-03-01

    The effectivity of 193nm photoresists as dry etch masks is becoming more and more critical as the size of integrated devices shrinks. 193nm resists are known to be much less resistant to dry etching than 248nm resists based on a poly(hydroxystyrene) polymer backbone. The decrease in the resist film budget implies a better etch resistance to use single layer 193nm photoresists for the 65nm node and beyond. In spite of significant improvements made in the past decade regarding the etch resistance of photoresists, much of the fundamental chemistry and physics that could explain the behaviour of these materials has to be better understood. Such knowledge is necessary in order to propose materials and etch processes for the next technology nodes (45nm and below). In this paper, we report our studies on the etch behaviour of different 193nm resist materials as a function of etch chemistry. In a first step, we focus our attention on the interactions between photoresists and the reactive species of a plasma during a dry etch step. Etch experiments were carried out in a DPS (Decoupled Plasma Source) high density chamber. The gas chemistry in particular was changed to check the role of the plasma reactive species on the resist. O II, Cl II, CF 4, HBr and Ar gas were used. Etch rates and chemical modifications of different materials were quantified by ellipsometry, Fourier Transformed Infrared Spectroscopy (FTIR), and X-Ray Photoelectrons Spectroscopy (XPS). We evaluated different materials including 248nm model polymer backbones (pure PHS or functionalized PHS), and 193nm model polymers (PMMA and acrylate polymers) or resist formulations. Besides the influence of resist chemistry, the impact of plasma parameters was addressed.

  1. Sub-100 nm patterning of supported bilayers by nanoshaving lithography.

    PubMed

    Shi, Jinjun; Chen, Jixin; Cremer, Paul S

    2008-03-01

    Sub-100 nm wide supported phospholipid bilayers (SLBs) were patterned on a planar borosilicate substrate by AFM-based nanoshaving lithography. First, a bovine serum albumin monolayer was coated on the glass and then selectively removed in long strips by an AFM tip. The width of vacant strips could be controlled down to 15 nm. Bilayer lines could be formed within the vacant strips by vesicle fusion. It was found that stable bilayers formed by this method had a lower size limit of approximately 55 nm in width. This size limit stems from a balance between a favorable bilayer adhesion energy and an unfavorable bilayer edge energy. PMID:18257567

  2. 80 nm tunable DBR-free semiconductor disk laser

    NASA Astrophysics Data System (ADS)

    Yang, Z.; Albrecht, A. R.; Cederberg, J. G.; Sheik-Bahae, M.

    2016-07-01

    We report a widely tunable optically pumped distributed Bragg reflector (DBR)-free semiconductor disk laser with 6 W continuous wave output power near 1055 nm when using a 2% output coupler. Using only high reflecting mirrors, the lasing wavelength is centered at 1034 nm and can be tuned up to a record 80 nm by using a birefringent filter. We attribute such wide tunability to the unique broad effective gain bandwidth of DBR-free semiconductor disk lasers achieved by eliminating the active mirror geometry.

  3. All-fibre ytterbium laser tunable within 45 nm

    SciTech Connect

    Abdullina, S R; Babin, S A; Vlasov, A A; Kablukov, S I; Shelemba, I S; Kurkov, A S

    2007-12-31

    A tunable ytterbium-doped fibre laser is fabricated. The laser is tuned by using a tunable fibre Bragg grating (FBG) as a selecting intracavity element. The laser is tunable within 45 nm (from 1063 to 1108 nm) and emits {approx}6 W in the line of width {approx}0.15 nm, the output power and linewidth being virtually invariable within the tuning range. The method is proposed for synchronous tuning the highly reflecting and output FBGs, and a tunable ytterbium all-fibre laser is built. (lasers)

  4. Practice Gaps: Drug Reactions.

    PubMed

    Wolverton, Stephen E

    2016-07-01

    The term "drug reactions" is relevant to dermatology in three categories of reactions: cutaneous drug reactions without systemic features, cutaneous drug reactions with systemic features, and systemic drugs prescribed by the dermatologist with systematic adverse effects. This article uses examples from each of these categories to illustrate several important principles central to drug reaction diagnosis and management. The information presented will help clinicians attain the highest possible level of certainty before making clinical decisions. PMID:27363888

  5. Reaction Selectivity in Heterogeneous Catalysis

    SciTech Connect

    Somorjai, Gabor A.; Kliewer, Christopher J.

    2009-02-02

    The understanding of selectivity in heterogeneous catalysis is of paramount importance to our society today. In this review we outline the current state of the art in research on selectivity in heterogeneous catalysis. Current in-situ surface science techniques have revealed several important features of catalytic selectivity. Sum frequency generation vibrational spectroscopy has shown us the importance of understanding the reaction intermediates and mechanism of a heterogeneous reaction, and can readily yield information as to the effect of temperature, pressure, catalyst geometry, surface promoters, and catalyst composition on the reaction mechanism. DFT calculations are quickly approaching the ability to assist in the interpretation of observed surface spectra, thereby making surface spectroscopy an even more powerful tool. HP-STM has revealed three vitally important parameters in heterogeneous selectivity: adsorbate mobility, catalyst mobility, and selective site-blocking. The development of size controlled nanoparticles from 0.8 to 10 nm, of controlled shape, and of controlled bimetallic composition has revealed several important variables for catalytic selectivity. Lastly, DFT calculations may be paving the way to guiding the composition choice for multi-metallic heterogeneous catalysis for the intelligent design of catalysts incorporating the many factors of selectivity we have learned.

  6. Removal of copper oxide from copper surfaces using Q-switched Nd:YAG radiation at 1064 nm, 532 nm, and 266 nm

    NASA Astrophysics Data System (ADS)

    Kearns, Aileen; Fischer, C.; Watkins, Kenneth G.; Glasmacher, Mathias; Steen, William M.; Kheyrandish, H.; Brown, A.

    1997-08-01

    During electronic device fabrication it is necessary to remove the oxides from copper surfaces prior to soldering in order to improve the surface wetability and achieve a good quality solder joint. The usual method of achieving this is by using acids in a flux. The work reported here explores the possibility of removing these oxides by laser cleaning using the harmonics of a Q-switched Nd:YAG laser, a technique which could be incorporated into a industrial laser soldering process. The effect of Q-switched Nd:YAG radiation (5 - 10 ns pulses), at 1064 nm, 532 nm and 266 nm, on the oxidized surface of a copper alloy foil is studied with increasing fluence. In order to successfully compare the effect of increasing fluence at the three wavelengths each area treated was only subjected to one laser pulse. The laser treated surfaces were characterized using optical microscopy, SEM, and surface analysis performed by static secondary ion mass spectrometry (SSIMS). SSIMS and SNMS (secondary neutral mass spectrometry) with mechanical depth profilometry were used to characterize the oxide layer. The reflectivity of the oxidized plates for the three wavelengths was ascertained using a reflectivity spectrometer. Successful cleaning was achieved at all wavelengths, above certain threshold values which defined the lower end of the process operating window for single pulse operation. The threshold for the cleaning process decreased with laser wavelength. Surface melting was evident at the lowest fluences examined for all the wavelengths (< .5 J/cm2). This value is well below the lower end of the process windows of all wavelengths. Microscopic `explosive' features were found at the onset of copper oxide removal possibly resulting from ionization or a plasma induced shock waves. There was some possible evidence of mechanical effects at 1064 nm and 532 nm. Large amounts of sputtered debris was found around the 266 nm craters. A SSIMS analysis was performed on the 532 nm spots. The

  7. Metastasis suppressors Nm23H1 and Nm23H2 differentially regulate neoplastic transformation and tumorigenesis.

    PubMed

    Tong, Yao; Yung, Lisa Y; Wong, Yung H

    2015-06-01

    Nm23H1 and H2 are prototypical metastasis suppressors with diverse functions, but recent studies suggest that they may also regulate tumorigenesis. Here, we employed both cellular and in vivo assays to examine the effect of Nm23H1 and H2 on tumorigenesis induced by oncogenic Ras and/or p53 deficiency. Co-expression of Nm23H1 but not H2 in NIH3T3 cells effectively suppressed neoplastic transformation and tumorigenesis induced by the oncogenic H-Ras G12V mutant. Overexpression of Nm23H1 but not H2 also inhibited tumorigenesis by human cervical cancer HeLa cells with p53 deficiency. However, in human non-small-cell lung carcinoma H1299 cells harboring N-Ras Q61K oncogenic mutation and p53 deletion, overexpression of Nm23H1 did not affect tumorigenesis in nude mice assays, while overexpression of Nm23H2 enhanced tumor growth with elevated expression of the c-Myc proto-oncogene. Collectively, these results suggest that Nm23H1 and H2 have differential abilities to modulate tumorigenesis. PMID:25748386

  8. Efficient laser operation of Nd3+:Lu2O3 at various wavelengths between 917 nm and 1463 nm

    NASA Astrophysics Data System (ADS)

    von Brunn, P.; Heuer, A. M.; Fornasiero, L.; Huber, G.; Kränkel, C.

    2016-08-01

    Even though the first Nd3+-doped sesquioxide lasers have been realized more than 50 years ago, up to now no reports on efficient laser operation of Nd3+:doped sesquioxides can be found. In this work, we review the favorable spectroscopic properties of the sesquioxide Nd3+:Lu2O3 in terms of ground state absorption, stimulated emission, and excited state absorption cross sections as well as the upper level lifetime. Making use of these properties, we achieved efficient laser performance on eight different laser transitions in the wavelength range between 917 nm and 1463 nm under Ti:sapphire laser pumping using state-of-the-art HEM-grown Nd3+:Lu2O3 crystals with good optical quality. At the strongest transition around 1076 nm we determined a slope efficiency of 69%, which represents the highest efficiency ever obtained for a Nd3+-doped sesquioxide. Furthermore, we could generate watt level output powers and high slope efficiencies for seven other transitions. Lasers at 917 nm, 1053 nm, 1108 nm and 1463 nm were realized for the first time and the latter represents one of the longest laser wavelengths obtained on the 4F3/2  →  4I13/2 transition in Nd3+-doped materials.

  9. High-resolution optical signatures of fresh and aged explosives in the 420nm to 620nm illumination range

    NASA Astrophysics Data System (ADS)

    Lunsford, Robert; Grun, Jacob; Gump, Jared

    2012-06-01

    Optical signatures of fresh and aged explosives are measured and compared to determine whether there exist differences in the signatures that can be exploited for detection. The explosives examined are RDX, TNT, and HMX, which have been heated for two weeks at 75 degrees centigrade or irradiated for two weeks with a 15-Watt ultraviolet lamp (254nm). The optical signatures are obtained by illuminating the samples with a sequence of laser wavelengths between 420nm and 620nm in 10 nm steps and measuring the spectra of light scattered from the sample at each laser wavelength. The measurements are performed on the Naval Research Laboratory's SWOrRD instrument. SWOrRD is capable of illuminating a sample with laser wavelength between 210nm and 2000nm, in steps of 0.1nm, and measuring the spectrum of light scattered from the sample at each wavelength. SWOrRD's broad tuning range, high average power (1- 300mW), narrow line width (< 4cm-1), and rapid wavelength tunability enable these measurements. Results, based on more than 80 measurements - each at 21 sequential laser wavelengths, indicate that the variation in spectral line amplitude observed when altering laser illumination wavelength differs between fresh and aged explosives. Thus, an instrument for rapid and reagent-less differentiation between aged and fresh explosives, based on illumination with a few appropriately chosen laser wavelengths appears feasible.

  10. Photochemical cycloaddition reactions of cyanoacetylene and dicyanoacetylene

    NASA Technical Reports Server (NTRS)

    Ferris, J. P.; Guillemin, J. C.

    1990-01-01

    Photolysis of cyanoacetylene with 185- or 206-nm light yields 1,3,5-tricyanobenzene while 254-nm radiation yields a mixture of tetracyanocyclooctatetraenes, 1,2,4- and 1,3,5-tricyanobenzene. A polymer of cyanoacetylene is the major photoproduct. 1,3,5-Tricarbomethoxybenzene was the only photoproduct identified from the irradiation of methyl propiolate at 254 nm. Mono-, di-, and tricyanobenzenes are formed by irradiation of mixtures of acetylene and cyanoacetylene at 185, 206, and 254 nm along with trace amounts of cyclooctatetraenes. No photoadducts were detected on photolysis of mixtures of cyanoacetylene and CO or HCN. The tetracyanocyclooctatetraene structures were established by UV, MS, and NMR analyses. The 1H NMR of the product mixture exhibited a singlet at delta 7.028 consistent with either 1 or 2 and two singlets at delta 6.85 and 6.91 assigned to 3. Photolysis of mixtures of dicyanoacetylene and acetylene with either 185- or 206-nm light yielded 1,2-dicyanobenzene and (E,Z)-1-buten-3-yne-1,4-dicarbonitrile. These products were also obtained using 254-nm light along with a mixture of tetracyanocyclooctatetraenes. The same three singlets were observed in this product mixture as were observed in the tetracyanocyclooctatetraenes obtained from cyanoacetylene. From this observation it was concluded that the delta 7.02 signal is due to 2 and not 1. The photolysis of cyanoacetylene and dicyanoacetylene in the presence of ethylene with 185-nm light yields 1-cyanocylobutene and 1,2-dicyanocyclobutene, respectively. 2-Cyanobutadiene and 2,3-dicyanobutadiene are the photoproducts with 254-nm light. Reaction pathways are proposed to explain these findings.

  11. Compact frequency-quadrupled pulsed 1030nm fiber laser

    NASA Astrophysics Data System (ADS)

    McIntosh, Chris; Goldberg, Lew; Cole, Brian; DiLazaro, Tom; Hays, Alan D.

    2016-03-01

    A compact 1030nm fiber laser for ultraviolet generation at 257.5nm is presented. The laser employs a short length of highly-doped, large core (20μm), coiled polarization-maintaining ytterbium-doped double-clad fiber pumped by a wavelength-stabilized 975nm diode. It is passively Q-switched via a Cr4+:YAG saturable absorber and generates 2.4W at 1030nm in a 110μJ pulse train. Lithium triborate (LBO) and beta-barium borate (BBO) are used to achieve 325mW average power at the fourth harmonic. The laser's small form factor, narrow linewidth and modest power consumption are suitable for use in a man-portable ultraviolet Raman explosives detection system.

  12. Fiber-integrated 780 nm source for visible parametric generation.

    PubMed

    Hu, D J J; Murray, R T; Legg, T; Runcorn, T H; Zhang, M; Woodward, R I; Lim, J L; Wang, Y; Luan, F; Gu, B; Shum, P P; Kelleher, E J R; Popov, S V; Taylor, J R

    2014-12-01

    We report the development of a fully fiber-integrated pulsed master oscillator power fibre amplifier (MOPFA) source at 780 nm, producing 3.5 W of average power with 410 ps pulses at a repetition rate of 50 MHz. The source consists of an intensity modulated 1560 nm laser diode amplified in an erbium fiber amplifier chain, followed by a fiber coupled periodically poled lithium niobate crystal module for frequency doubling. The source is then used for generating visible light through four-wave mixing in a length of highly nonlinear photonic crystal fiber: 105 mW at 668 nm and 95 mW at 662 nm are obtained, with pump to anti-Stokes conversion slope efficiencies exceeding 6% in both cases. PMID:25606903

  13. Photorefractive effect at 775 nm in doped lithium niobate crystals

    SciTech Connect

    Nava, G.; Minzioni, P.; Cristiani, I.; Degiorgio, V.; Argiolas, N.; Bazzan, M.; Ciampolillo, M. V.; Pozza, G.; Sada, C.

    2013-07-15

    The photorefractive effect induced by 775-nm laser light on doped lithium niobate crystals is investigated by the direct observation in the far field of the transmitted-beam distortion as a function of time. Measurements performed at various Zr-doping concentrations and different light intensities show that the 775-nm light beam induces a steady-state photorefractive effect comparable to that of 532-nm light, but the observed build-up time of the photovoltaic field is longer by three-orders of magnitude. The 775-nm photorefractivity of lithium niobate crystals doped with 3 mol. % ZrO{sub 2} or with 5.5 mol. % MgO is found to be negligible.

  14. 100-nm node lithography with KrF?

    NASA Astrophysics Data System (ADS)

    Fritze, Michael; Tyrrell, Brian; Astolfi, David K.; Yost, Donna; Davis, Paul; Wheeler, Bruce; Mallen, Renee D.; Jarmolowicz, J.; Cann, Susan G.; Liu, Hua-Yu; Ma, M.; Chan, David Y.; Rhyins, Peter D.; Carney, Chris; Ferri, John E.; Blachowicz, B. A.

    2001-09-01

    We present results looking into the feasibility of 100-nm Node imaging using KrF, 248-nm, exposure technology. This possibility is not currently envisioned by the 1999 ITRS Roadmap which lists 5 possible options for this 2005 Node, not including KrF. We show that double-exposure strong phase- shift, combined with two mask OPC, is capable of correcting the significant proximity effects present for 100-nm Node imaging at these low k1 factors. We also introduce a new PSM Paradigm, dubbed 'GRATEFUL,' that can image aggressive 100-nm Node features without using OPC. This is achieved by utilizing an optimized 'dense-only' imaging approach. The method also allows the re-use of a single PSM for multiple levels and designs, thus addressing the mask cost and turnaround time issues of concern in PSM technology.

  15. Absolute measurement of F2-laser power at 157 nm

    SciTech Connect

    Kueck, Stefan; Brandt, Friedhelm; Kremling, Hans-Albert; Gottwald, Alexander; Hoehl, Arne; Richter, Mathias

    2006-05-10

    We report a comparison of laser power measurements at the F2-laser wavelength oaf nm made at two facilities of the Physikalisch-Technische Bundesanstalt (PTB), the German national metrology institute. At the PTB laboratory at the electron storage ring BESSY II in Berlin, the scale for laser power was directly traced to a cryogenic radiometer operating at 157 nm, whereas at the PTB laser radiometry facility in Braunschweig the calibration of transfer detectors was performed with a newly developed standard for laser power at 157 nm, which is traceable in several steps to a cryogenic radiometer operating at 633 nm. The comparison was performed under vacuum conditions with laser pulse energies of?10 {mu}J, however with different average powers because different primary standard radiometers were used. The relative deviation for the responsivity of the transfer detector was 4.8% and thus within the combined standard uncertainty.

  16. 980 nm narrow linewidth Yb-doped phosphate fiber laser

    NASA Astrophysics Data System (ADS)

    Li, Pingxue; Yao, Yifei; Hu, Haowei; Chi, Junjie; Yang, Chun; Zhao, Ziqiang; Zhang, Guangju

    2014-12-01

    A narrow-linewidth ytterbium (Yb)-doped phosphate fiber laser based on fiber Bragg grating (FBG) operating around 980 nm is reported. Two different kinds of cavity are applied to obtain the 980 nm narrow-linewidth output. One kind of the cavity consists of a 0.35 nm broadband lindwidth high-reflection FBG and the Yb-doped phosphate fiber end with 0° angle, which generates a maximum output power of 25 mW. The other kind of resonator is composed of a single mode Yb-doped phosphate fiber and a pair of FBGs. Over 10.7 mW stable continuous wave are obtained with two longitudinal modes at 980 nm. We have given a detailed analysis and discussion for the results.

  17. Raman spectroscopy using 1550 nm (retina-safe) laser excitation.

    PubMed

    Brouillette, Carl; Huang, Hermes; Smith, Wayne; Farquharson, Stuart

    2011-05-01

    During the past decade, the use of portable Raman analyzers for field measurements has grown dramatically. However, most analyzers use 785 nm excitation lasers that can cause permanent eye damage. To overcome this safety concern, we have built a portable Fourier transform (FT) Raman analyzer using a 1550 nm retina-safe excitation laser and have compared its performance to our 1064 nm FT-Raman analyzer, which uses the same optical design. Raman theory predicts approximately five times lower peak intensities at 1550 nm. Although we found that intensities were as much as 20 times less intense, the analyzer is still capable of measuring spectra of sufficient quality to identify and differentiate chemicals. PMID:21513601

  18. The Missing Solar Irradiance Spectrum: 1 to 7 nm

    NASA Astrophysics Data System (ADS)

    Sojka, J. J.; Lewis, M.; David, M.; Schunk, R. W.; Woods, T. N.; Eparvier, F. G.; Warren, H. P.

    2015-12-01

    During large X-class flares the Earth's upper atmospheric E-region responds immediately to solar photons in the 1 to 7 nm range. The response can change the E-region density by factors approaching 10, create large changes in conductivity, and plague HF communications. GOES-XRS provide 0.1 to 0.8 nm and a 0.05 to 0.4 nm integral channels; SOHO-SEM provided a 0 to 50 nm irradiance; TIMED and SORCE-XPS diode measurements also integrated down to 0.1 nm; and most recently SDO-EVE provided a 0.1 to 7 nm irradiance. For atmospheric response to solar flares the cadence is also crucial. Both GOES and SDO provided integral measurements at 10 seconds or better. Unfortunately these measurements have failed to capture the 1 to 7 nm spectral changes that occur during flares. It is these spectral changes that create the major impact since the ionization cross-section of the dominant atmospheric species, N2 and O2, both contain step function changes in the cross-sections. Models of the solar irradiance over this critical wavelength regime have suffered from the need to model the spectral variability based on incomplete measurements. The most sophisticated empirical model FISM [Chamberlin et al., 2008] used 1 nm spectral binning and various implementations of the above integral measurements to describe the 1 to 7 nm irradiance. Since excellent solar observations exist at other wavelengths it is possible to construct an empirical model of the solar atmosphere and then use this model to infer the spectral distribution at wavelengths below 5 nm. This differential emission measure approach has been used successfully in other contexts [e.g., Warren, 2005, Chamberlin et al., 2009]. This paper contrasts the broadband versus spectrally resolved descriptions of the incoming irradiance that affects the upper atmospheric E-layer. The results provide a prescription of what wavelength resolution would be needed to adequately measure the incoming solar irradiance in the 1 to 7 nm range.

  19. Low-k/copper integration scheme suitable for ULSI manufacturing from 90nm to 45nm nodes

    NASA Astrophysics Data System (ADS)

    Nogami, T.; Lane, S.; Fukasawa, M.; Ida, K.; Angyal, M.; Chanda, K.; Chen, F.; Christiansen, C.; Cohen, S.; Cullinan, M.; Dziobkowski, C.; Fitzsimmons, J.; Flaitz, P.; Grill, A.; Gill, J.; Inoue, K.; Klymko, N.; Kumar, K.; Labelle, C.; Lane, M.; Li, B.; Liniger, E.; Madon, A.; Malone, K.; Martin, J.; McGahay, V.; McLaughlin, P.; Melville, I.; Minami, M.; Molis, S.; Nguyen, S.; Penny, C.; Restaino, D.; Sakamoto, A.; Sankar, M.; Sherwood, M.; Simonyi, E.; Shimooka, Y.; Tai, L.; Widodo, J.; Wildman, H.; Ono, M.; McHerron, D.; Nye, H.; Davis, C.; Sankaran, S.; Edelstein, D.; Ivers, T.

    2005-11-01

    This paper discusses low-k/copper integration schemes which has been in production in the 90 nm node, have been developed in the 65 nm node, and should be taken in the 45 nm node. While our baseline 65 nm BEOL process has been developed by extension and simple shrinkage of our PECVD SiCOH integration which has been in production in the 90 nm node with our SiCOH film having k=3.0, the 65 nm SiCOH integration has two other options to go to extend to lower capacitance. One is to add porosity to become ultra low-k (ULK). The other is to stay with low-k SiCOH, which is modified to have a "lower-k". The effective k- value attained with the lower-k (k=2.8) SiCOH processed in the "Direct CMP" scheme is very close to that with an ULK (k=2.5) SiCOH film built with the "Hard Mask Retention" scheme. This paper first describes consideration of these two damascene schemes, whose comparison leads to the conclusion that the lower-k SiCOH integration can have more advantages in terms of process simplicity and extendibility of our 90 nm scheme under certain assumptions. Then describing the k=2.8 SiCOH film development and its successful integration, damascene schemes for 45nm nodes are discussed based on our learning from development of the lower-k 65nm scheme. Capability of modern dry etchers to define the finer patterns, non-uniformity of CMP, and susceptibility to plasma and mechanical strength and adhesion of ULK are discussed as factors to hamper the applicability of ULK.

  20. Applications of combination wavelength (1060-nm and 530-nm) and pulsed Nd:YAG laser for contact laser surgery.

    PubMed

    Liu, K R; Peyman, G A; Myers, J D; Hamlin, S A; Katoh, N

    1989-01-01

    Two pulsed neodimium yittrium aluminum garnet (Nd:YAG) laser systems were evaluated for contact surgery through a fiberoptic system with a sapphire tip. Pulsed Nd:YAG laser at 1060 nm was as effective as continuous-wave Nd:YAG laser in producing tissue incisions. A combination of 1060-nm and 530-nm wavelengths achieved smooth cutting at lower energy levels. Corneal endothelial cell damage occurred at the high power level (7 watts) required for smooth underwater incisions with both continuous wave and pulsed lasers. PMID:2733255

  1. Trends in nanosecond melanosome microcavitation up to 1540 nm

    NASA Astrophysics Data System (ADS)

    Schmidt, Morgan S.; Kennedy, Paul K.; Noojin, Gary D.; Vincelette, Rebecca L.; Thomas, Robert J.; Rockwell, Benjamin A.

    2015-09-01

    Thresholds for microcavitation of bovine and porcine melanosomes were previously reported, using single nanosecond (ns) laser pulses in the visible (532 nm) and the near-infrared (NIR) from 1000 to 1319 nm. Here, we report average radiant exposure thresholds for bovine melanosome microcavitation at additional NIR wavelengths up to 1540 nm, which range from ˜0.159 J/cm2 at 800 nm to 4.5 J/cm2 at 1540 nm. Melanosome absorption coefficients were also estimated, and decreased with increasing wavelength. These values were compared to retinal pigment epithelium coefficients, and to water absorption, over the same wavelength range. Corneal total intraocular energy retinal damage threshold values were estimated and compared to the previous (2007) and recently changed (2014) maximum permissible exposure (MPE) safe levels. Results provide additional data that support the recent changes to the MPE levels, as well as the first microcavitation data at 1540 nm, a wavelength for which melanosome microcavitation may be an ns-pulse skin damage mechanism.

  2. Tissue measurement using 1064 nm dispersive Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Lieber, Chad A.; Wu, Huawen; Yang, William

    2013-03-01

    The use of Raman spectroscopy to provide characterization and diagnosis of biological tissues has shown increasing success in recent years. Most of this work has been performed using near-infrared laser sources such as 785 or 830 nm, in a balance of reduced intrinsic fluorescence in the tissues and quantum efficiency in the silicon detectors often used. However, even at these wavelengths, many tissues still exhibit strong or prohibitive fluorescence, and these wavelengths still cause autofluorescence in many common sampling materials, such as glass. In this study, we demonstrate the use of 1064 nm dispersive Raman spectroscopy for the study of biological tissues. A number of tissues are evaluated using the 1064 nm system and compared with the spectra obtained from a 785 nm system. Sampling materials are similarly compared. These results show that 1064 nm dispersive Raman spectroscopy provides a viable solution for measurement of highly fluorescent biological tissues such as liver and kidney, which are difficult or impossible to extract Raman at 785 nm.

  3. Magneto-optical trap for metastable helium at 389 nm

    SciTech Connect

    Koelemeij, J.C.J.; Stas, R.J.W.; Hogervorst, W.; Vassen, W.

    2003-05-01

    We have constructed a magneto-optical trap (MOT) for metastable triplet helium atoms utilizing the 2 {sup 3}S{sub 1}{yields}3 {sup 3}P{sub 2} line at 389 nm as the trapping and cooling transition. The far-red-detuned MOT (detuning {delta}=-41 MHz) typically contains few times 10{sup 7} atoms at a relatively high ({approx}10{sup 9} cm{sup -3}) density, which is a consequence of the large momentum transfer per photon at 389 nm and a small two-body loss rate coefficient (2x10{sup -10} cm{sup 3}/s<{beta}<1.0x10{sup -9} cm{sup 3}/s). The two-body loss rate is more than five times smaller than in a MOT on the commonly used 2 {sup 3}S{sub 1}{yields}2 {sup 3}P{sub 2} line at 1083 nm. Furthermore, laser cooling at 389 nm results in temperatures somewhat lower than those achieved using 1083 nm. The 389-nm MOT exhibits small losses due to two-photon ionization, which have been investigated as well.

  4. High-index nanocomposite photoresist for 193-nm lithography

    NASA Astrophysics Data System (ADS)

    Bae, Woo Jin; Trikeriotis, Makros; Rodriguez, Robert; Zettel, Michael F.; Piscani, Emil; Ober, Christopher K.; Giannelis, Emmanuel P.; Zimmerman, Paul

    2009-03-01

    In immersion lithography, high index fluids are used to increase the numerical aperture (NA) of the imaging system and decrease the minimum printable feature size. Water has been used in first generation immersion lithography at 193 nm to reach the 45 nm node, but to reach the 38 and 32 nm nodes, fluids and resists with a higher index than water are needed. A critical issue hindering the implementation of 193i at the 32 nm node is the availability of high refractive index (n > 1.8) and low optical absorption fluids and resists. It is critical to note that high index resists are necessary only when a high refractive index fluid is in use. High index resist improves the depth of focus (DOF) even without high index fluids. In this study, high refractive index nanoparticles have been synthesized and introduced into a resist matrix to increase the overall refractive index. The strategy followed is to synthesize PGMEA-soluble nanoparticles and then disperse them into a 193 nm resist. High index nanoparticles 1-2 nm in diameter were synthesized by a combination of hydrolysis and sol-gel methods. A ligand exchange method was used, allowing the surface of the nanoparticles to be modified with photoresist-friendly moieties to help them disperse uniformly in the resist matrix. The refractive index and ultraviolet absorbance were measured to evaluate the quality of next generation immersion lithography resist materials.

  5. Power scaling of laser diode pumped Pr3+:LiYF4 cw lasers: efficient laser operation at 522.6 nm, 545.9 nm, 607.2 nm, and 639.5 nm.

    PubMed

    Gün, Teoman; Metz, Philip; Huber, Günter

    2011-03-15

    We report efficient cw laser operation of laser diode pumped Pr(3+)-doped LiYF4 crystals in the visible spectral region. Using two InGaN laser diodes emitting at λ(P)=443.9 nm with maximum output power of 1 W each and a 2.9-mm-long crystal with a doping concentration of 0.5%, output powers of 938 mW, 418 mW, 384 mW, and 773 mW were achieved for the laser wavelengths 639.5 nm, 607.2 nm, 545.9 nm, and 522.6 nm, respectively. The maximum absorbed pump powers were approximately 1.5 W, resulting in slope efficiencies of 63.6%, 32.0%, 52.1%, and 61.5%, as well as electro-optical efficiencies of 9.4%, 4.2%, 3.8%, and 7.7%, respectively. Within these experiments, laser diode-pumped laser action at 545.9 nm was demonstrated for what is believed to be the first time. PMID:21403756

  6. High-performance 193nm photoresists based on fluorosulfonamide

    NASA Astrophysics Data System (ADS)

    Li, Wenjie; Chen, Kuang-Jung; Kwong, Ranee; Lawson, Margaret C.; Khojasteh, Mahmoud; Popova, Irene; Varanasi, P. Rao; Shimokawa, Tsutomu; Yamaguchi, Yoshikazu; Kusumoto, Shiro; Sugiura, Makoto; Kawakami, Takanori; Slezak, Mark; Dabbagh, Gary; Liu, Zhi

    2007-03-01

    The combination of immersion lithography and reticle enhancement techniques (RETs) has extended 193nm lithography into the 45nm node and possibly beyond. In order to fulfill the tight pitch and small critical dimension requirements of these future technology nodes, the performance of 193nm resist materials needs to further improve. In this paper, a high performance 193nm photoresist system based on fluorosulfonamide (FSM) is designed and developed. The FSM group has good transparency at 193nm. Compared to the commonly used hexafluoroalcohol (HFA) group, the trifluoromethyl sulfonamide (TFSM) functionality has a lower pKa value and contains less fluorine atoms. Polymers containing the TFSM functionality have exhibited improved dissolution properties and better etch resistance than their HFA counterparts. Resists based on the FSM-containing polymers have shown superior lithographic performance for line, trench and contact hole levels under the 45nm node exposure conditions. In addition, FSM resists have also demonstrated excellent bright field and dark field compatibility and thereby make it possible to use one resist for both bright field and dark field level applications. The structure, property and lithographic performance of the FSM resist system are reported.

  7. Detonation wave profiles measured in plastic bonded explosives using 1550 nm photon doppler velocimetry (PDV)

    SciTech Connect

    Gustavsen, Richard L; Bartram, Brian D; Sanchez, Nathaniel J

    2009-01-01

    We present detonation wave profiles measured in two TATB based explosives and two HMX based explosives. Profiles were measured at the interface of the explosive and a Lithium-Fluoride (LiF) window using 1550 nm Photon Doppler Velocimetry (PDV). Planar detonations were produced by impacting the explosive with a projectile launched in a gas-gun. The impact state was varied to produce varied distance to detonation, and therefore varied support of the Taylor wave following the Chapman-Jouget (CJ) or sonic state. Profiles from experiments with different support should be the same between the Von-Neumann (VN) spike and CJ state and different thereafter. Comparison of profiles with differing support, therefore, allows us to estimate reaction zone lengths. For the TATB based explosive, a reaction zone length of {approx} 3.9 mm, 500 ns was measured in EDC-35, and a reaction zone length of {approx} 6.3 mm, 800 ns was measured in PBX 9502 pre-cooled to -55 C. The respective VN spike state was 2.25 {+-} 0.05 km/s in EDC-35 and 2.4 {+-} 0.1 km/s in the cooled PBX 9502. We do not believe we have resolved either the VN spike state (> 2.6 km/s) nor the reaction zone length (<< 50 ns) in the HMX based explosives.

  8. Recent developments in Fourier domain mode locked lasers for optical coherence tomography: imaging at 1310 nm vs. 1550 nm wavelength.

    PubMed

    Biedermann, Benjamin R; Wieser, Wolfgang; Eigenwillig, Christoph M; Huber, Robert

    2009-07-01

    We report on recent progress in Fourier domain mode-locking (FDML) technology. The paper focuses on developments beyond pushing the speed of these laser sources. After an overview of improvements to FDML over the last three years, a brief analysis of OCT imaging using FDML lasers with different wavelengths is presented. For the first time, high speed, high quality FDML imaging at 1550 nm is presented and compared to a system at 1310 nm. The imaging results of human skin for both wavelengths are compared and analyzed. Sample arm optics, power on the sample, heterodyne gain, detection bandwidth, colour cut levels and sample location have been identical to identify the influence of difference in scattering and water absorption. The imaging performance at 1310 nm in human skin is only slightly better and the results suggest that water absorption only marginally affects the penetration depth in human skin at 1550 nm. For several applications this wavelength may be preferred. PMID:19565537

  9. The Spectrum of Th-Ar Hollow Cathode Lamps in the 691nm to 5804nm region Database

    National Institute of Standards and Technology Data Gateway

    SRD 161 The Spectrum of Th-Ar Hollow Cathode Lamps in the 691nm to 5804nm region Database (Web, free access)   This atlas presents observations of the infra-red (IR) spectrum of a low current Th-Ar hollow cathode lamp with the 2-m Fourier transform spectrometer (FTS) at NIST. These observations establish more than 2400 lines that are suitable for use as wavelength standards in the range 691 nm to 5804 nm. The observations were made in collaboration with the European Southern Observatory (ESO), in order to provide calibration reference data for new high-resolution Echelle spectrographs, such as the Cryogenic High-Resolution IR Echelle Spectrograph ([CRIRES]), ESO's new IR spectrograph at the Very Large Telescope in Chile.

  10. 750 nm 1.5 W frequency-doubled semiconductor disk laser with a 44 nm tuning range.

    PubMed

    Saarinen, Esa J; Lyytikäinen, Jari; Ranta, Sanna; Rantamäki, Antti; Sirbu, Alexei; Iakovlev, Vladimir; Kapon, Eli; Okhotnikov, Oleg G

    2015-10-01

    We demonstrate 1.5 W of output power at the wavelength of 750 nm by intracavity frequency doubling a wafer-fused semiconductor disk laser diode-pumped at 980 nm. An optical-to-optical efficiency of 8.3% was achieved using a bismuth borate crystal. The wavelength of the doubled emission could be tuned from 720 to 764 nm with an intracavity birefringent plate. The beam quality parameter M2 of the laser output was measured to be below 1.5 at all pump powers. The laser is a promising tool for biomedical applications that can take advantage of the large penetration depth of light in tissue in the 700-800 nm spectral range. PMID:26421536

  11. High-efficiency high-brightness diode lasers at 1470 nm/1550 nm for medical and defense applications

    NASA Astrophysics Data System (ADS)

    Gallup, Kendra; Ungar, Jeff; Vaissie, Laurent; Lammert, Rob; Hu, Wentao

    2012-03-01

    Diode lasers in the 1400 nm to 1600 nm regime are used in a variety of applications including pumping Er:YAG lasers, range finding, materials processing, aesthetic medical treatments and surgery. In addition to the compact size, efficiency, and low cost advantages of traditional diode lasers, high power semiconductor lasers in the eye-safe regime are becoming widely used in an effort to minimize the unintended impact of potentially hazardous scattered optical radiation from the laser source, the optical delivery system, or the target itself. In this article we describe the performance of high efficiency high brightness InP laser bars at 1470nm and 1550nm developed at QPC Lasers for applications ranging from surgery to rangefinding.

  12. The enhancement of 21.2%-power conversion efficiency in polymer photovoltaic cells by using mixed Au nanoparticles with a wide absorption spectrum of 400 nm-1000 nm

    NASA Astrophysics Data System (ADS)

    Hao, Jing-Yu; Xu, Ying; Zhang, Yu-Pei; Chen, Shu-Fen; Li, Xing-Ao; Wang, Lian-Hui; Huang, Wei

    2015-04-01

    Au nanoparticles (NPs) mixed with a majority of bone-like, rod, and cube shapes and a minority of irregular spheres, which can generate a wide absorption spectrum of 400 nm-1000 nm and three localized surface plasmon resonance peaks, respectively, at 525, 575, and 775 nm, are introduced into the hole extraction layer poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) to improve optical-to-electrical conversion performances in polymer photovoltaic cells. With the doping concentration of Au NPs optimized, the cell performance is significantly improved: the short-circuit current density and power conversion efficiency of the poly(3-hexylthiophene): [6,6]-phenyl-C60-butyric acid methyl ester cell are increased by 20.54% and 21.2%, reaching 11.15 mA·cm-2 and 4.23%. The variations of optical, electrical, and morphology with the incorporation of Au NPs in the cells are analyzed in detail, and our results demonstrate that the cell performance improvement can be attributed to a synergistic reaction, including: 1) both the localized surface plasmon resonance- and scattering-induced absorption enhancement of the active layer, 2) Au doping-induced hole transport/extraction ability enhancement, and 3) large interface roughness-induced efficient exciton dissociation and hole collection. Project supported by the National Basic Research Program of China (Grant Nos. 2015CB932202 and 2012CB933301), the National Natural Science Foundation of China (Grant Nos. 61274065, 51173081, 61136003, BZ2010043, 51372119, and 51172110), the Science Fund from the Ministry of Education of China (Grant No. IRT1148), the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20113223110005), the Priority Academic Program Development of Jiangsu Provincial Higher Education Institutions (Grant No. YX03001), and the National Synergistic Innovation Center for Advanced Materials and the Synergetic Innovation Center for Organic Electronics and

  13. Extensive angiokeratoma circumscriptum - successful treatment with 595-nm variable-pulse pulsed dye laser and 755-nm long-pulse pulsed alexandrite laser.

    PubMed

    Baumgartner, Ján; Šimaljaková, Mária; Babál, Pavel

    2016-06-01

    Angiokeratomas are rare vascular mucocutaneous lesions characterized by small-vessel ectasias in the upper dermis with reactive epidermal changes. Angiokeratoma circumscriptum (AC) is the rarest among the five types in the current classification of angiokeratoma. We present a case of an extensive AC in 19-year-old women with Fitzpatrick skin type I of the left lower extremity, characterized by a significant morphological heterogeneity of the lesions, intermittent bleeding, and negative psychological impact. Histopathological examination after deep biopsy was consistent with that of angiokeratoma. The association with metabolic diseases (Fabry disease) was excluded by ophthalmological, biochemical, and genetic examinations. Nuclear magnetic resonance imaging has not detected deep vascular hyperplasia pathognomic for verrucous hemangioma. The combined treatment with 595-nm variable-pulse pulsed dye laser (VPPDL) and 755-nm long-pulse pulsed alexandrite laser (LPPAL) with dynamic cooling device led to significant removal of the pathological vascular tissue of AC. Only a slight degree of secondary reactions (dyspigmentations and texture changes) occurred. No recurrence was observed after postoperative interval of 9 months. We recommend VPPDL and LPPAL for the treatment of extensive AC. PMID:26736060

  14. Kinetics and mechanism investigation on the destruction of oxytetracycline by UV-254nm activation of persulfate.

    PubMed

    Liu, Yiqing; He, Xuexiang; Fu, Yongsheng; Dionysiou, Dionysios D

    2016-03-15

    Oxytetracycline (OTC), an important broad-spectrum antibiotic, has been detected extensively in various environmental systems, which may have a detrimental impact on ecosystem and human health through the development of drug resistant bacteria and pathogens. In this study, the degradation of OTC was evaluated by UV-254nm activated persulfate (PS). The observed UV fluence based pseudo first-order rate constant (kobs) was found to be the highest at near neutral pH conditions (pH 5.5-8.5). Presence of various natural water constituents had different effects on OTC degradation, with a significant enhancement in the presence of bicarbonate or Cu(2+). Limited elimination of total organic carbon (TOC) and PS was observed during the mineralization of OTC. Transformation byproducts in the presence and absence of hydroxyl radical scavenging agent tert-butanol (t-BuOH) were identified using ultra-high definition accurate-mass quadrupole time-of-flight liquid chromatography/mass spectrometer (LC-QTOF/MS). Potential OTC degradation mechanism was subsequently proposed revealing four different reaction pathways by SO4(-) reaction including hydroxylation (+16Da), demethylation (-14Da), decarbonylation (-28Da) and dehydration (-18Da). This study suggests that UV-254nm/PS is a promising treatment technology for the control of water pollution caused by emerging contaminants such as OTC. PMID:26686482

  15. Compact Fiber Laser for 589nm Laser Guide Star Generation

    NASA Astrophysics Data System (ADS)

    Pennington, D.; Drobshoff, D.; Mitchell, S.; Brown, A.

    Laser guide stars are crucial to the broad use of astronomical adaptive optics, because they facilitate access to a large fraction of possible locations on the sky. Lasers tuned to the 589 nm atomic sodium resonance can create an artificial beacon at altitudes of 95-105 km, thus coming close to reproducing the light path of starlight. The deployment of multiconjugate adaptive optics on large aperture telescopes world-wide will require the use of three to nine sodium laser guide stars in order to achieve uniform correction over the aperture with a high Strehl value. Current estimates place the minimum required laser power at > 10 W per laser for a continuous wave source, though a pulsed format, nominally 6?s in length at ~ 16.7 kHz, is currently preferred as it would enable tracking the laser through the Na layer to mitigate spot elongation. The lasers also need to be compact, efficient, robust and turnkey. We are developing an all-fiber laser system for generating a 589 nm source for laser-guided adaptive optics. Fiber lasers are more compact and insensitive to alignment than their bulk laser counterparts, and the heat-dissipation characteristics of fibers, coupled with the high efficiencies demonstrated and excellent spatial mode characteristics, make them a preferred candidate for many high power applications. Our design is based on sum-frequency mixing an Er/Yb:doped fiber laser operating at 1583 nm with a 938 nm Nd:silica fiber laser in a periodically poled crystal to generate 589 nm. We have demonstrated 14 W at 1583 nm with an Er/Yb:doped fiber laser, based on a Koheras single frequency fiber oscillator amplified in an IPG Photonics fiber amplifier. The Nd:silica fiber laser is a somewhat more novel device, since the Nd3+ ions must operate on the resonance transition (i.e. 4F3/2-4I9/2), while suppressing ASE losses at the more conventional 1088 nm transition. Optimization of the ratio of the fiber core and cladding permits operation of the laser at room

  16. Generation of Thermospheric OI 845 nm Emission by Bowen Fluorescence

    NASA Astrophysics Data System (ADS)

    Huestis, D. L.; Sharpee, B. D.; Cosby, P. C.; Slanger, T. G.

    2006-12-01

    777 and 845 nm emissions from the 3p-3s multiplets of atomic oxygen are commonly observed at non-auroral latitudes in the terrestrial nightglow. By studying the relative strengths of these emissions we can learn something about the mechanisms that produce them and what they can teach us about the atmosphere. Recently [1] we have used intensity-calibrated sky spectra from the Keck telescopes to investigate the relative strengths of a wide range of O-atom Rydberg lines and have confirmed that electron-ion radiative recombination is a primary source of excitation for both the triplet and quintet systems. Following the intensity of the 777 and 845 nm lines during the night, we find that for most of the night the quintet 777 nm line is consistently stronger than the triplet 845 nm line, with a nearly constant intensity ratio I(777)/I(845) near 2.3, although both intensities fall rapidly as the night progresses. However, late in the night the 845 nm intensity levels off, while the 777 nm intensity continues to fall, and the I(777)/I(845) ratio plunges by a factor of 5-10. We interpret these observations as indicating that the O-atom quintet states are still being excited by the same mechanism as earlier in the night, i.e. radiative recombination, but some triplet states are also being excited by an additional mechanism. Such a mechanism has been proposed before [2-6] but not previously observed directly in the terrestrial nightglow. The oxygen triplet 3d-2p transition at 102.576 nm is in close coincidence with the solar hydrogen Lyman-β line at 102.572 nm. Radiative transport in the hydrogen geocorona will deliver Lyman-β intensity into the Earth's shadow and will produce triplet O(3d 3D) high in the atmosphere, even prior to direct solar illumination. The result is observable in a radiative cascade sequence 3d-3p(1129 nm) → 3p- 3s(845 nm) → 3s-2p(130 nm). A similar effect is observed in the H-α emission, which is also excited by Lyman-β absorption. This process

  17. Microdrilling of metals using femtosecond laser pulses and high average powers at 515 nm and 1030 nm

    NASA Astrophysics Data System (ADS)

    Döring, S.; Ancona, A.; Hädrich, S.; Limpert, J.; Nolte, S.; Tünnermann, A.

    2010-07-01

    We investigate the microdrilling of metals (stainless steel, copper and tungsten) for two different wavelengths, 1030 nm and 515 nm, in the regime of femtosecond laser pulses. An ytterbium-doped fibre CPA system provides high pulse energies (up to 70 μJ) and high repetition rates (up to 800 kHz), corresponding to high average powers of about 50 W, for this experimental study.

  18. Measurements of Photoabsorpton Cross Sections and their Temperature Dependence for CO2 in the 170nm to 200nm Region

    NASA Astrophysics Data System (ADS)

    Parkinson, W. H.; Yoshino, K.

    2001-11-01

    All the photochemical models for the predominately CO2 Martian atmosphere ar e very sensitive to the amount of CO2 and to the values and spectral details of the absorpton cross sections of CO2 in the region 170nm-200nm. Earlier we had measured and published absolute cross sections of CO2 in the region 118.0 nm-175.5 nm at 295K and 195K. We have recently extended these measurements from 170 nm to 200 nm at 300K and 1 95K. The new measurements have been carried out at high resolution with our 6.65 -m normal incidence , photoelectric spectrometer. To measure the weak photoabsorption of the CO2 bands in the wavelength region 170 --200 nm, we required a high column density of the gas. We obtained this by using a multi pass technique, a White cell. The White cell was designed to have a distance of 1.50 m between two main mirrors, and was set for four, double pas ses making a path length of 12.0 m. CO2 gas was frozen in a stainless cylinder immersed in liquid nitrogen, and t he frozen product (dryice) was pumped by the diffusion pump for purification. The CO2 was warmed up slowly and kept in the cylinder at high pressure. The CO2 pressure used in the White cell was varied from 1 to 1000 Torr depend ing on the wavelength region, and was measured with a a capacitance manometer (M KS Baratron, 10 Torr and 1000 Torr). We divided the spectral region into twenty sections of about 1.5 nm extent. At each scan range, another scan was obtained from the emission spectrum of the fourth positive bands of CO for wavelength calibration. We acknowledge funding from NASA, grant NAGS-7859 to Harvard College Observatory.

  19. Imaging performance and challenges of 10nm and 7nm logic nodes with 0.33 NA EUV

    NASA Astrophysics Data System (ADS)

    van Setten, Eelco; Schiffelers, Guido; Psara, Eleni; Oorschot, Dorothe; Davydova, Natalia; Finders, Jo; Depre, Laurent; Farys, Vincent

    2014-10-01

    The NXE:3300B is ASML's third generation EUV system and has an NA of 0.33 and is positioned at a resolution of 22nm, which can be extended down to 18nm and below with off-axis illumination at full transmission. Multiple systems have been qualified and installed at customers. The NXE:3300B succeeds the NXE:3100 system (NA of 0.25), which has allowed customers to gain valuable EUV experience. It is expected that EUV will be adopted first for critical Logic layers at 10nm and 7nm nodes, such as Metal-1, to avoid the complexity of triple patterning schemes using ArF immersion. In this paper we will evaluate the imaging performance of (sub-)10nm node Logic M1 on the NXE:3300B EUV scanner. We will show the line-end performance of tip-to-tip and tip-to-space test features for various pitches and illumination settings and the performance enhancement obtained by means of a 1st round of OPC. We will also show the magnitude of local variations. The Logic M1 cell is evaluated at various critical features to identify hot spots. A 2nd round OPC model was calibrated of which we will show the model accuracy and ability to predict hot spots in the Logic M1 cell. The calibrated OPC model is used to predict the expected performance at 7nm node Logic using off-axis illumination at 16nm minimum half pitch. Initial results of L/S exposed on the NXE:3300B at 7nm node resolutions will be shown. An outlook is given to future 0.33 NA systems on the ASML roadmap with enhanced illuminator capabilities to further improve performance and process window.

  20. Considerations for fine hole patterning for the 7nm node

    NASA Astrophysics Data System (ADS)

    Yaegashi, Hidetami; Oyama, Kenichi; Hara, Arisa; Natori, Sakurako; Yamauchi, Shohei; Yamato, Masatoshi; Koike, Kyohei

    2016-03-01

    One of the practical candidates to produce 7nm node logic devices is to use the multiple patterning with 193-immersion exposure. For the multiple patterning, it is important to evaluate the relation between the number of mask layer and the minimum pitch systematically to judge the device manufacturability. Although the number of the time of patterning, namely LE(Litho-Etch) ^ x-time, and overlay steps have to be reduced, there are some challenges in miniaturization of hole size below 20nm. Various process fluctuations on contact hole have a direct impact on device performance. According to the technical trend, 12nm diameter hole on 30nm-pitch hole will be needed on 7nm node. Extreme ultraviolet lithography (EUV) and Directed self-assembly (DSA) are attracting considerable attention to obtain small feature size pattern, however, 193-immersion still has the potential to extend optical lithography cost-effectively for sub-7nm node. The objective of this work is to study the process variation challenges and resolution in post-processing for the CD-bias control to meet sub-20nm diameter contact hole. Another pattern modulation is also demonstrated during post-processing step for hole shrink. With the realization that pattern fidelity and pattern placement management will limit scaling long before devices and interconnects fail to perform intrinsically, the talk will also outline how circle edge roughness (CER) and Local-CD uniformity can correct efficiency. On the other hand, 1D Gridded-Design-Rules layout (1D layout) has simple rectangular shapes. Also, we have demonstrated CD-bias modification on short trench pattern to cut grating line for its fabrication.

  1. Analysis of Cervical Supernatant Samples Luminescence Using 355 nm Laser

    NASA Astrophysics Data System (ADS)

    Vaitkuviene, A.; Gegzna, V.; Kurtinaitiene, R.; Stanikunas, R.; Rimiene, J.; Vaitkus, J.

    2010-05-01

    The biomarker discovery for accurate detection and diagnosis of cervical carcinoma and its malignant precursors represents one of the current challenges in clinical medicine. Laser induced autofluorescence spectra in cervical smear content were fitted to predict the cervical epithelium diagnosis as a lab off "optical biopsy" method. Liquid PAP supernatant sediment dried on Quartz plate spectroscopy was performed by 355 nm Nd YAG microlaser STA-1 (Standa, Ltd). For comparison a liquid supernatant spectroscopy was formed by laboratory "Perkin Elmer LS 50B spetrometer at 290, 300, 310 nm excitations. Analysis of spectrum was performed by approximation using the multi-peaks program with Lorentz functions for the liquid samples and with Gaussian functions for the dry samples. Ratio of spectral components area to the area under whole experimental curve (SPP) was calculated. The spectral components were compared by averages of SPP using Mann-Whitney U-test in histology groups. Results. Differentiation of Normal and HSIL/CIN2+ cases in whole supernatant could be performed by stationary laboratory lamp spectroscopy at excitation 290 nm and emission >379 nm with accuracy AUC 0,69, Sens 0,72, Spec 0,65. Differentiation Normal versus HSIL/CIN2+ groups in dried enriched supernatant could be performed by 355 nm microlaser excitation at emission 405-424 nm with accuracy (AUC 0,96, Sens 0,91, Spec 1.00). Diagnostic algorithm could be created for all histology groups differentiation under 355 nm excitation. Microlaser induced "optical biopsy "looks promising method for cervical screening at the point of care.

  2. High-brightness 800nm fiber-coupled laser diodes

    NASA Astrophysics Data System (ADS)

    Berk, Yuri; Levy, Moshe; Rappaport, Noam; Tessler, Renana; Peleg, Ophir; Shamay, Moshe; Yanson, Dan; Klumel, Genadi; Dahan, Nir; Baskin, Ilya; Shkedi, Lior

    2014-03-01

    Fiber-coupled laser diodes have become essential sources for fiber laser pumping and direct energy applications. Single emitters offer reliable multi-watt output power from a 100 m lateral emission aperture. By their combination and fiber coupling, pump powers up to 100 W can be achieved from a low-NA fiber pigtail. Whilst in the 9xx nm spectral range the single emitter technology is very mature with <10W output per chip, at 800nm the reliable output power from a single emitter is limited to 4 W - 5 W. Consequently, commercially available fiber coupled modules only deliver 5W - 15W at around 800nm, almost an order of magnitude down from the 9xx range pumps. To bridge this gap, we report our advancement in the brightness and reliability of 800nm single emitters. By optimizing the wafer structure, laser cavity and facet passivation process we have demonstrated QCW device operation up to 19W limited by catastrophic optical damage to the 100 μm aperture. In CW operation, the devices reach 14 W output followed by a reversible thermal rollover and a complete device shutdown at high currents, with the performance fully rebounded after cooling. We also report the beam properties of our 800nm single emitters and provide a comparative analysis with the 9xx nm single emitter family. Pump modules integrating several of these emitters with a 105 μm / 0.15 NA delivery fiber reach 35W in CW at 808 nm. We discuss the key opto-mechanical parameters that will enable further brightness scaling of multi-emitter pump modules.

  3. Facile Synthesis of Sub-20 nm Silver Nanowires through a Bromide-Mediated Polyol Method.

    PubMed

    da Silva, Robson Rosa; Yang, Miaoxin; Choi, Sang-Il; Chi, Miaofang; Luo, Ming; Zhang, Chao; Li, Zhi-Yuan; Camargo, Pedro H C; Ribeiro, Sidney José Lima; Xia, Younan

    2016-08-23

    Essentially all of the Ag nanowires reported in the literature have sizes larger than 30 nm in diameter. In this article, we report a simple and robust approach to the synthesis of Ag nanowires with diameters below 20 nm and aspect ratios over 1000 using a one-pot polyol method. The Ag nanowires took a penta-twinned structure, and they could be obtained rapidly (<35 min) and in high morphology purity (>85% of the as-obtained solid product) under atmospheric pressure. The key to the success of this synthesis is to restrain the nanowires from lateral growth by employing both Br(-) ions and poly(vinylpyrrolidone) with a high molecular weight of 1 300 000 g/mol to cap the {100} side faces, together with the use of a syringe pump to slowly introduce AgNO3 into the reaction solution. By optimizing the ratios between the capping agents and AgNO3, we were able to slow down the reduction kinetics and effectively direct the Ag nanowires to grow along the longitudinal direction only. The nanowires showed great mechanical flexibility and could be bent with acute angles without breaking. Because of their small diameters, the transverse localized surface plasmon resonance peak of the Ag nanowires could be pushed down to the ultraviolet region, below 400 nm, making them ideal conductive elements for the fabrication of touch screens, solar cells, and smart windows. PMID:27483165

  4. Effects of amines on formation of sub-3 nm particles and their subsequent growth

    SciTech Connect

    Yu H.; McGraw R.; Lee S.-H.

    2012-01-28

    Field observations and quantum chemical calculations suggest that amines can be important for formation of nanometer size particles. Amines and ammonia often have common atmospheric emission sources and the similar chemical and physical properties. While the effects of ammonia on aerosol nucleation have been previously investigated, laboratory studies of homogeneous nucleation involving amines are lacking. We have made kinetics studies of multicomponent nucleation (MCN) with sulfuric acid, water, ammonia and amines under conditions relevant to the atmosphere. Low concentrations of aerosol precursors were measured with chemical ionization mass spectrometers (CIMS) to provide constrained precursor concentrations needed for nucleation. Particle sizes larger than {approx}2 nm were measured with a nano-differential mobility analyzer (nano-DMA), and number concentrations of particles larger than {approx}1 nm were measured with a particle size magnifier (PSM). Our observations provide the laboratory evidence that amines indeed can participate in aerosol nucleation and growth at the molecular cluster level. The enhancement of particle number concentrations due to several atmospherically relevant amine compounds and ammonia were related to the basicity of these compounds, indicating that acid-base reactions may contribute to the formation of sub-3 nm particles.

  5. A 1.5-W frequency doubled semiconductor disk laser tunable over 40 nm at around 745 nm

    NASA Astrophysics Data System (ADS)

    Saarinen, Esa J.; Lyytikäinen, Jari; Ranta, Sanna; Rantamäki, Antti; Saarela, Antti; Sirbu, Alexei; Iakovlev, Vladimir; Kapon, Eli; Okhotnikov, Oleg G.

    2016-03-01

    We report on a semiconductor disk laser emitting 1.5 W of output power at the wavelength of 745 nm via intracavity frequency doubling. The high power level and the < 40 nm tuning range make the laser a promising tool for medical treatments that rely on photosensitizing agents and biomarkers in the transmission window of tissue between 700 and 800 nm. The InP-based gain structure of the laser was wafer-fused with a GaAs-based bottom mirror and thermally managed with an intracavity diamond heat spreader. The structure was pumped with commercial low-cost 980 nm laser diode modules. Laser emission at 1490 nm was frequency-doubled with a bismuth borate crystal that was cut for type I critical phase matching. At the maximum output power, we achieved an optical-to-optical efficiency of 8.3% with beam quality parameter M2 below 1.5. The laser wavelength could be tuned with an intracavity birefringent plate from 720 to 764 nm.

  6. Fabricating nanopores with diameters of sub-1 nm to 3 nm using multilevel pulse-voltage injection

    PubMed Central

    Yanagi, Itaru; Akahori, Rena; Hatano, Toshiyuki; Takeda, Ken-ichi

    2014-01-01

    To date, solid-state nanopores have been fabricated primarily through a focused-electronic beam via TEM. For mass production, however, a TEM beam is not suitable and an alternative fabrication method is required. Recently, a simple method for fabricating solid-state nanopores was reported by Kwok, H. et al. and used to fabricate a nanopore (down to 2 nm in size) in a membrane via dielectric breakdown. In the present study, to fabricate smaller nanopores stably—specifically with a diameter of 1 to 2 nm (which is an essential size for identifying each nucleotide)—via dielectric breakdown, a technique called “multilevel pulse-voltage injection” (MPVI) is proposed and evaluated. MPVI can generate nanopores with diameters of sub-1 nm in a 10-nm-thick Si3N4 membrane with a probability of 90%. The generated nanopores can be widened to the desired size (as high as 3 nm in diameter) with sub-nanometre precision, and the mean effective thickness of the fabricated nanopores was 3.7 nm. PMID:24847795

  7. Optical coherence tomography based imaging of dental demineralisation and cavity restoration in 840 nm and 1310 nm wavelength regions

    NASA Astrophysics Data System (ADS)

    Damodaran, Vani; Rao, Suresh Ranga; Vasa, Nilesh J.

    2016-08-01

    In this paper, a study of in-house built optical coherence tomography (OCT) system with a wavelength of 840 nm for imaging of dental caries, progress in demineralisation and cavity restoration is presented. The caries when imaged with the 840 nm OCT system showed minute demineralisation in the order of 5 μm. The OCT system was also proposed to study the growth of lesion and this was demonstrated by artificially inducing caries with a demineralisation solution of pH 4.8. The progress of carious lesion to a depth of about 50-60 μm after 60 hours of demineralisation was clearly observed with the 840 nm OCT system. The tooth samples were subjected to accelerated demineralisation condition at pH of approximately 2.3 to study the adverse effects and the onset of cavity formation was clearly observed. The restoration of cavity was also studied by employing different restorative materials (filled and unfilled). In the case of restoration without filler material (unfilled), the restoration boundaries were clearly observed. Overall, results were comparable with that of the widely used 1310 nm OCT system. In the case of restoration with filler material, the 1310 nm OCT imaging displayed better imaging capacity due to lower scattering than 840 nm imaging.

  8. Electro-optically Q-switched dual-wavelength Nd:YLF laser emitting at 1047 nm and 1053 nm

    NASA Astrophysics Data System (ADS)

    Men, Shaojie; Liu, Zhaojun; Cong, Zhenhua; Li, Yongfu; Zhang, Xingyu

    2015-05-01

    A flash-lamp pumped electro-optically Q-switched dual-wavelength Nd:YLF laser is demonstrated. Two Nd:YLF crystals placed in two cavities are employed to generate orthogonally polarized 1047 nm and 1053 nm radiations, respectively. The two cavities are jointed together by a polarizer and share the same electro-optical Q-switch. Two narrow-band pass filters are used to block unexpected oscillations at the hold-off state of the electro-optical Q-switch. In this case, electro-optical Q-switching is able to operate successfully. With pulse synchronization realized, the maximum output energy of 66.2 mJ and 83.9 mJ are obtained for 1047 nm and 1053 nm lasers, respectively. Correspondingly, the minimum pulse width is both 17 ns for 1047 nm and 1053 nm lasers. Sum frequency generation is realized. This demonstrates the potential of this laser in difference-frequency generations to obtain terahertz wave.

  9. Magnetoelastically induced magnetic anisotropy transition in [CoO5nm/CoPt7nm]5 multilayer films

    NASA Astrophysics Data System (ADS)

    Guo, Lei; Harumoto, Takashi; Sannomiya, Takumi; Muraishi, Shinji; Nakamura, Yoshio; Shi, Ji

    2016-06-01

    The magnetic anisotropy transition of [CoO5nm/CoPt7nm]5 multilayer film with respect to post-annealing has been studied systematically. It undergoes a smooth transition from longitudinal magnetic anisotropy (LMA) to perpendicular magnetic anisotropy (PMA) upon annealing and returns backward to LMA at high temperature of 550 °C. The strongest PMA of [CoO5nm/CoPt7nm]5 is achieved after post-annealing at 300 °C and the tolerable post-annealing temperature with strong PMA is up to 400 °C, which indicates this multilayer film could be a potential candidate for the PMA application at middle-high-temperature-region between 300 °C and 400 °C. The mechanism responsible for the transition of magnetic anisotropy has been investigated by analyzing CoO/CoPt interface and CoPt layer internal stress. It is found the effective PMA energy is proportional to the in-plane tensile stress of CoPt layer but is inversely proportional to the roughness of CoO/CoPt interface. Finally, by means of low temperature experiment we demonstrate the magnetic anisotropy transition observed in [CoO5nm/CoPt7nm]5 multilayer film is mainly attributed to the change of CoPt layer in-plane tensile stress.

  10. Research of the Additional Losses Occurring in Optical Fiber at its Multiple Bends in the Range Waves 1310nm, 1550nm and 1625nm Long

    NASA Astrophysics Data System (ADS)

    Yurchenko, A. V.; Gorlov, N. I.; Alkina, A. D.; Mekhtiev, A. D.; Kovtun, A. A.

    2016-01-01

    Article is devoted to research of the additional losses occurring in the optical fiber at its multiple bends in the range waves of 1310 nanometers, 1550 nanometers and 1625 nanometers long. Article is directed on creation of the external factors methods which allow to estimate and eliminate negative influence. The automated way of calculation of losses at a bend is developed. Results of scientific researches are used by engineers of “Kazaktelekom” AS for practical definition of losses service conditions. For modeling the Wolfram|Alpha environment — the knowledge base and a set of computing algorithms was chosen. The greatest losses are noted on wavelength 1310nm and 1625nm. All dependences are nonlinear. Losses with each following excess are multiplicative.

  11. Observation of Quiet Limb in He I 1083.0 nm, H Paschen alpha1281.8 nm and H Brackett gamma 2166.1 nm lines

    NASA Astrophysics Data System (ADS)

    Prasad Choudhary, Debi

    2016-05-01

    In this paper, we shall present the results of an observational study of the quiet solar limb in the near infrared lines using the New IR Array Camera (NAC) and the vertical spectrograph at the focal plane of McMath-Pierce telescope. The NAC, at the exit port of the spectrograph, was used to record the limb spectrum in HeI 1083.0 nm, Hydrogen Paschen 1281.8 nm and Brackett 2165.5 nm wavelength regions. The NAC is a 1024x1024 InSb Alladin III Detector operating over 1-5 micron range with high density sampling at 0.018 arc second/pixel. The all-reflective optical train minimizes number of surfaces and eliminates ghosts leading to low scatter, ghost-free optics. The close-cycle cryogenic provides a stable cooling environment over six hour period with an accuracy of 0.01K leading to low dark current. The low read out noise combined with low scattered light and dark current makes NAC an ideal detector for making high quality infrared spectral observations of solar limb. The limb spectrums were obtained by placing the spectrograph slit perpendicular to the limb at an interval of 10 degrees around the solar disk. We shall report the intensity profile, line-of-sight velocity and line width distribution around the sun derived from the spectra along the slit.

  12. Microfluidic chemical reaction circuits

    DOEpatents

    Lee, Chung-cheng; Sui, Guodong; Elizarov, Arkadij; Kolb, Hartmuth C.; Huang, Jiang; Heath, James R.; Phelps, Michael E.; Quake, Stephen R.; Tseng, Hsian-rong; Wyatt, Paul; Daridon, Antoine

    2012-06-26

    New microfluidic devices, useful for carrying out chemical reactions, are provided. The devices are adapted for on-chip solvent exchange, chemical processes requiring multiple chemical reactions, and rapid concentration of reagents.

  13. Continuous detonation reaction engine

    NASA Technical Reports Server (NTRS)

    Lange, O. H.; Stein, R. J.; Tubbs, H. E.

    1968-01-01

    Reaction engine operates on the principles of a controlled condensed detonation rather than on the principles of gas expansion. The detonation results in reaction products that are expelled at a much higher velocity.

  14. Allergic reactions (image)

    MedlinePlus

    Allergic reaction is a sensitivity to a specific substance, called an allergen, that is contacted through the skin, inhaled into the lungs, swallowed or injected. The body's reaction to an allergen can be mild, such as ...

  15. Allergic reactions (image)

    MedlinePlus

    Allergic reaction can be provoked by skin contact with poison plants, chemicals and animal scratches, as well as by ... dust, nuts and shellfish, may also cause allergic reaction. Medications such as penicillin and other antibiotics are ...

  16. Microscale Thermite Reactions.

    ERIC Educational Resources Information Center

    Arnaiz, Francisco J.; Aguado, Rafael; Arnaiz, Susana

    1998-01-01

    Describes the adaptation of thermite (aluminum with metal oxides) reactions from whole-class demonstrations to student-run micro-reactions. Lists detailed directions and possible variations of the experiment. (WRM)

  17. Reaction coordinates for electron transfer reactions

    SciTech Connect

    Rasaiah, Jayendran C.; Zhu Jianjun

    2008-12-07

    The polarization fluctuation and energy gap formulations of the reaction coordinate for outer sphere electron transfer are linearly related to the constant energy constraint Lagrangian multiplier m in Marcus' theory of electron transfer. The quadratic dependence of the free energies of the reactant and product intermediates on m and m+1, respectively, leads to similar dependence of the free energies on the reaction coordinates and to the same dependence of the activation energy on the reorganization energy and the standard reaction free energy. Within the approximations of a continuum model of the solvent and linear response of the longitudinal polarization to the electric field in Marcus' theory, both formulations of the reaction coordinate are expected to lead to the same results.

  18. Switching Properties of sub-100 nm Perpendicular Magnetic Tunnel Junctions

    NASA Astrophysics Data System (ADS)

    Tryputen, Larysa; Piotrowski, Stephan; Bapna, Mukund; Chien, Chia-Ling; Wang, Weigang; Majetich, Sara; Ross, Caroline

    2015-03-01

    Perpendicular magnetic tunnel junctions (p-MTJs) have great potential for realizing high-density non-volatile memory and logic devices. It is critical to solve scalability problem to implement such devices, to achieve low resistance area and to reduce switching current density while maintaining thermal stability. We present our recent results on fabrication of high resolution Ta/CoFeB/MgO/CoFeB/Ta p-MTJ devices and characterization of their switching properties as well as topography and current mapping by using nanoscale Conductive Atomic Force Microscopy. Our patterning method is based on using hydrogen silsesquioxane resist mask combined with ion beam etching. It allows to fabricate p-MTJ devices down to 40 nm in diameter while maintaining the magnetic quality of the multilayers. Repeatable, consistent switching behaviour has been observed in the obtained p-MTJ devices of 500 nm down to 40 nm with 10 - 800 mV voltage applied. Switching field increased as device diameter decreased, from 580 Oe at 500 nm (MR = 10%) to 410 Oe at 80 nm (MR = 9%). We discuss the effect of device sizes on the switching properties. This work was supported in part by C-SPIN, one of the six centers of STARnet, a Semiconductor Research Corporation Program sponsored by MARCO and DARPA and in part through the National Science Foundation through NCN-Needs Program, Contract 12207020-EEC.

  19. Coronal Diagnostics from Narrowband Images Around 30.4 nm

    NASA Astrophysics Data System (ADS)

    Andretta, V.; Telloni, D.; Del Zanna, G.

    2012-07-01

    Images taken in the band centered at 30.4 nm are routinely used to map the radiance of the He ii Ly α line on the solar disk. That line is one of the strongest, if not the strongest, line in the EUV observed in the solar spectrum, and one of the few lines in that wavelength range providing information on the upper chromosphere or lower transition region. However, when observing the off-limb corona, the contribution from the nearby Si xi 30.3 nm line can become significant. In this work we aim at estimating the relative contribution of those two lines in the solar corona around the minimum of solar activity. We combine measurements from CDS taken in August 2008 with temperature and density profiles from semiempirical models of the corona to compute the radiances of the two lines, and of other representative coronal lines ( e.g. Mg x 62.5 nm, Si xii 52.1 nm). Considering both diagnosed quantities from line ratios (temperatures and densities) and line radiances in absolute units, we obtain a good overall match between observations and models. We find that the Si xi line dominates the He ii line from just above the limb up to ≈ 2 R ⊙ in streamers, while its contribution to narrowband imaging in the 30.4 nm band is expected to become smaller, even negligible in the corona beyond ≈ 2 - 3 R ⊙, the precise value being strongly dependent on the coronal temperature profile.

  20. NM23 protein in neoplastic and nonneoplastic thyroid tissues.

    PubMed Central

    Bertheau, P.; De La Rosa, A.; Steeg, P. S.; Merino, M. J.

    1994-01-01

    The expression of nm23 gene products has been associated with a lower metastatic potential and better outcome in malignant tumors. We have used immunohistochemistry to study the expression of nm23 protein in thyroid tissues from 101 patients consisting of 78 malignant neoplasms, 13 adenomas, and 10 other benign conditions. Cytoplasmic staining for nm23 protein was identified in normal tissues and in most benign and malignant lesions and did not correlate with either histological type of clinical outcome. Nuclear staining was seen in 93% of normal tissues and in 29% of primary carcinomas of the thyroid and was associated with a longer disease-free survival (P = 0.03). Membranous staining was present in some tumors but absent in normal thyroid. In conclusion, nm23 protein has a combined pattern of distribution among subcellular compartments in thyroid tissues. Although there was no significant association between cytoplasmic or membranous expression and histological type of tumor or survival nm23 nuclear expression may be a useful marker in assessing the evolution of thyroid tumors. Images Figure 1 PMID:8030752

  1. Absorption spectrum of DNA for wavelengths greater than 300 nm

    SciTech Connect

    Sutherland, J.C.; Griffin, K.P.

    1981-06-01

    Although DNA absorption at wavelengths greater than 300 nm is much weaker than that at shorter wavelengths, this absorption seems to be responsible for much of the biological damage caused by solar radiation of wavelengths less than 320 nm. Accurate measurement of the absorption spectrum of DNA above 300 nm is complicated by turbidity characteristic of concentrated solutions of DNA. We have measured the absorption spectra of DNA from calf thymus, Clostridium perfringens, Escherichia coli, Micrococcus luteus, salmon testis, and human placenta using procedures which separate optical density due to true absorption from that due to turbidity. Above 300 nm, the relative absorption of DNA increases as a function of guanine-cytosine content, presumably because the absorption of guanine is much greater than the absorption of adenine at these wavelengths. This result suggests that the photophysical processes which follow absorption of a long-wavelength photon may, on the average, differ from those induced by shorter-wavelength photons. It may also explain the lower quantum yield for the killing of cells by wavelengths above 300 nm compared to that by shorter wavelengths.

  2. Taking the X Architecture to the 65-nm technology node

    NASA Astrophysics Data System (ADS)

    Sarma, Robin C.; Smayling, Michael C.; Arora, Narain; Nagata, Toshiyuki; Duane, Michael P.; Shah, Santosh; Keston, Harris J.; Oemardani, Shiany

    2004-05-01

    The X Architecture is a new way of orienting the interconnect on an integrated circuit using diagonal pathways, as well as the traditional right-angle, or Manhattan, configuration. By enabling designs with significantly less wire and fewer vias, the X Architecture can provide substantial improvements in chip performance, power consumption and cost. Members of the X Initiative semiconductor supply chain consortium have demonstrated the production worthiness of the X Architecture at the 130-nm and 90-nm process technology nodes. This paper presents an assessment of the manufacturing readiness of the X Architecture for the 65-nm technology node. The extent to which current production capabilities in mask writing, lithography, wafer processing, inspection and metrology can be used is discussed using the results from a 65-nm test chip. The project was a collaborative effort amongst a number of companies in the IC fabrication supply chain. Applied Materials fabricated the 65-nm X Architecture test chip at its Maydan Technology Center and leveraged the technology of other X Initiative members. Cadence Design Systems provided the test structure design and chip validation tools, Dai Nippon Printing produced the masks and Canon"s imaging system was employed for the photolithography.

  3. Catalytic diastereoselective petasis reactions.

    PubMed

    Muncipinto, Giovanni; Moquist, Philip N; Schreiber, Stuart L; Schaus, Scott E

    2011-08-22

    Multicomponent Petasis reactions: the first diastereoselective Petasis reaction catalyzed by chiral biphenols that enables the synthesis of syn and anti β-amino alcohols in pure form has been developed. The reaction exploits a multicomponent approach that involves boronates, α-hydroxy aldehydes, and amines. PMID:21751322

  4. Reaction efficiency effects on binary chemical reactions

    NASA Astrophysics Data System (ADS)

    Lazaridis, Filippos; Savara, Aditya; Argyrakis, Panos

    2014-09-01

    We study the effect of the variation of reaction efficiency in binary reactions. We use the well-known A + B → 0 model, which has been extensively studied in the past. We perform simulations on this model where we vary the efficiency of reaction, i.e., when two particles meet they do not instantly react, as has been assumed in previous studies, but they react with a probability γ, where γ is in the range 0 < γ < 1. Our results show that at small γ values the system is reaction limited, but as γ increases it crosses over to a diffusion limited behavior. At early times, for small γ values, the particle density falls slower than for larger γ values. This fall-off goes over a crossover point, around the value of γ = 0.50 for high initial densities. Under a variety of conditions simulated, we find that the crossover point was dependent on the initial concentration but not on the lattice size. For intermediate and long times simulations, all γ values (in the depleted reciprocal density versus time plot) converge to the same behavior. These theoretical results are useful in models of epidemic reactions and epidemic spreading, where a contagion from one neighbor to the next is not always successful but proceeds with a certain probability, an analogous effect with the reaction probability examined in the current work.

  5. Comparison of modeled NmE with NmE measured by the Boulder ionosonde near the spring equinox.

    NASA Astrophysics Data System (ADS)

    Pavlov, Anatoli; Pavlova, Nadezhda

    We present a comparison of the E-layer peak electron number densities, NmE, measured by the Boulder ionosonde during geomagnetically quiet conditions on 10 April 1996 at low solar activity, 2 April 1993 and 9 April 1978 during moderate solar activity conditions, and 10 April 1991 at high solar activity with numerical theoretical model calculations of NmE. Based on this comparison, the modified EUVAC model solar flux is necessary to increase by a factor of 2 at moderate and high solar activity in the wavelength range of 3.2-7.0 nm. If O (+) ( (4) S), O (+) ( (2) D), O (+) ( (2) P), and N (+) ions are not calculated, the value of NmE is decreased up to a factor of 1.12 at solar minimum and up to a factor of 1.23 for the moderate and high solar activity conditions. The production of N _{2} (+) ions by photoelectron-impact ionization of N _{2} increases the value of NmE up to a factor of 1.18 at low solar activity and up to a factor of 1.33 for the moderate and high solar activity levels. The increase in NmE due to the production of O _{2} (+) ions by photoelectron-impact ionization of O _{2} does not exceed 4 percent. A difference between the calculated electron, T _{e}, and neutral, T _{n}, temperatures is less than 1, 4, 20, 70, and 145 K at 105, 110, 120, 130, and 140 km altitude, respectively. Changes in NmE caused by this difference between T _{e} and T _{n} are negligible.

  6. Guaranteed discovery of the NmSuGra model

    SciTech Connect

    Balazs, Csaba; Carter, Daniel

    2008-11-23

    We analyze the discovery potential of the next-to-minimal supergravity motivated model: NmSuGra. This model is an extension of mSuGra by a gauge singlet, and contains only one additional parameter: {lambda}, the Higgs-singlet-Higgs coupling. NmSuGra solves the {mu}-problem and reduces the fine tuning of mSuGra. After identifying parameter space regions preferred by present experimental data, we show that these regions of NmSuGra are amenable to detection by the combination of the Large Hadron Collider and an upgraded Cryogenic Dark Matter Search. This conclusion holds strictly provided that the more than three sigma discrepancy in the difference of the experimental and the standard theoretical values of the anomalous magnetic moment of the muon prevails in the future.

  7. Sub-5 nm, globally aligned graphene nanoribbons on Ge(001)

    NASA Astrophysics Data System (ADS)

    Kiraly, Brian; Mannix, Andrew J.; Jacobberger, Robert M.; Fisher, Brandon L.; Arnold, Michael S.; Hersam, Mark C.; Guisinger, Nathan P.

    2016-05-01

    Graphene nanoribbons (GNRs) hold great promise for future electronics because of their edge and width dependent electronic bandgaps and exceptional transport properties. While significant progress toward GNR devices has been made, the field has been limited by difficulties achieving narrow widths, global alignment, and atomically pristine GNR edges on technologically relevant substrates. A recent advance has challenged these limits by using Ge(001) substrates to direct the bottom-up growth of GNRs with nearly pristine armchair edges and widths near ˜10 nm via atmospheric pressure chemical vapor deposition. In this work, the growth of GNRs on Ge(001) is extended to ultra-high vacuum conditions, resulting in the realization of GNRs with widths narrower than 5 nm. Armchair graphene nanoribbons oriented along Ge <110> surface directions are achieved with excellent width control and relatively large bandgaps. The bandgap magnitude and electronic uniformity of these sub-5 nm GNRs are well-suited for emerging nanoelectronic applications.

  8. Composition of 15-85 nm particles in marine air

    NASA Astrophysics Data System (ADS)

    Lawler, M. J.; Whitehead, J.; O'Dowd, C.; Monahan, C.; McFiggans, G.; Smith, J. N.

    2014-11-01

    The chemical composition of 15-85 nm diameter particles was measured at Mace Head, Ireland, during May 2011 using the TDCIMS (thermal desorption chemical ionization mass spectrometer). Measurable levels of chloride, sodium, and sulfate were present in essentially all collected samples of these particles at this coastal Atlantic site. Acetaldehyde and benzoic acid were also frequently detected. Concomitant particle hygroscopicity observations usually showed a sea-salt mode and a lower hygroscopicity mode with growth factors near to that of ammonium sulfate. There were many periods lasting from hours to about 2 days during which the 10-60 nm particle number increased dramatically in polar oceanic air. These periods were correlated with the presence of benzoic acid in the particles and an increase in the number of lower hygroscopicity mode particles. Very small (< 10 nm) particles were also present, suggesting that new particle formation contributed to these nanoparticle enhancement events.

  9. Developmental Function of Nm23/awd - A Mediator of Endocytosis

    PubMed Central

    Nallamothu, Gouthami; Dammai, Vincent; Hsu, Tien

    2009-01-01

    The metastasis suppressor gene Nm23 is highly conserved from yeast to human, implicating a critical developmental function. Studies in cultured mammalian cells have identified several potential functions, but many have not been directly verified in vivo. Here we summarize the studies on the Drosophila homologue of the Nm23 gene, named abnormal wing discs (awd), which shares 78% amino acid identity with the human Nm23-H1 and H2 isoforms. These studies confirmed that awd gene encodes a nucleoside diphosphate kinase, and provided strong evidence of a role for awd in regulating cell differentiation and motility via regulation of growth factor receptor signaling. The latter function is mainly mediated by control of endocytosis. This review provides a historical account of the discovery and subsequent analyses of the awd gene. We will also discuss the possible molecular function of the Awd protein that underlies the endocytic function. PMID:19373545

  10. High power narrowband 589 nm frequency doubled fibre laser source.

    PubMed

    Taylor, Luke; Feng, Yan; Calia, Domenico Bonaccini

    2009-08-17

    We demonstrate high-power high-efficiency cavity-enhanced second harmonic generation of an in-house built ultra-high spectral density (SBS-suppressed) 1178 nm narrowband Raman fibre amplifier. Up to 14.5 W 589 nm CW emission is achieved with linewidth Delta nu(589) < 7 MHz in a diffraction-limited beam, with peak external conversion efficiency of 86%. The inherently high spectral and spatial qualities of the 589 nm source are particularly suited to both spectroscopic and Laser Guide Star applications, given the seed laser can be easily frequency-locked to the Na D(2a) emission line. Further, we expect the technology to be extendable, at similar or higher powers, to wavelengths limited only by the seed-pump-pair availability. PMID:19687946

  11. New Vector Spectropolarimetry of Sunspots near 4000nm

    NASA Astrophysics Data System (ADS)

    Penn, Matthew J.; Coulter, Roy; Goode, Philip R.

    2014-06-01

    Magnetic sensitivity of spectral lines increases as the product of the wavelength and the Lande g-factor. While the most magnetically sensitive spectral line known is the Mg I 12318nm line, and observations are often made near 1600nm, little work has been done using solar spectral lines near 4000nmWe report on new solar spectropolarimetric observations at these wavelengths, made at the NSO McMath-Pierce facility with the NAC and at the NJIT New Solar Telescope using CYRA. Several photospheric absorption lines have been used to map a sunspot magnetic field, and molecular line Zeeman splitting has also been observed. Several "negative-g" molecular lines are seen, and an atomic line shows unusual profiles.

  12. High Power 938nm Cladding Pumped Fiber Laser

    SciTech Connect

    Dawson, J; Beach, R; Brobshoff, A; Liao, Z; Payne, S; Pennington, D; Taylor, L; Hackenberg, W; Bonaccini, D

    2002-12-26

    We have developed a Nd:doped cladding pumped fiber amplifier, which operates at 938nm with greater than 2W of output power. The core co-dopants were specifically chosen to enhance emission at 938nm. The fiber was liquid nitrogen cooled in order to achieve four-level laser operation on a laser transition that is normally three level at room temperature, thus permitting efficient cladding pumping of the amplifier. Wavelength selective attenuation was induced by bending the fiber around a mandrel, which permitted near complete suppression of amplified spontaneous emission at 1088nm. We are presently seeking to scale the output of this laser to 10W. We will discuss the fiber and laser design issues involved in scaling the laser to the 10W power level and present our most recent results.

  13. Novel EUV resist development for sub-14nm half pitch

    NASA Astrophysics Data System (ADS)

    Hori, Masafumi; Naruoka, Takehiko; Nakagawa, Hisashi; Fujisawa, Tomohisa; Kimoto, Takakazu; Shiratani, Motohiro; Nagai, Tomoki; Ayothi, Ramakrishnan; Hishiro, Yoshi; Hoshiko, Kenji; Kimura, Toru

    2015-03-01

    Extreme ultraviolet (EUV) lithography has emerged as a promising candidate for the manufacturing of semiconductor devices at the sub-14nm half pitch lines and spaces (LS) pattern for 7 nm node and beyond. The success of EUV lithography for the high volume manufacturing of semiconductor devices depends on the availability of suitable resist with high resolution and sensitivity. It is well-known that the key challenge for EUV resist is the simultaneous requirement of ultrahigh resolution (R), low line edge roughness (L) and high sensitivity (S). In this paper, we investigated and developed new chemically amplified resist (CAR) materials to achieve sub-14 nm hp resolution. We found that both resolution and sensitivity were improved simultaneously by controlling acid diffusion length and efficiency of acid generation using novel PAG and sensitizer. EUV lithography evaluation results obtained for new CAR on Micro Exposure Tool (MET) and NXE3300 system are described and the fundamentals are discussed.

  14. Porcine dermal lesions produced by 1540-nm laser radiation pulses

    NASA Astrophysics Data System (ADS)

    Roach, William P.; Johnson, Thomas E.

    2001-07-01

    Completion of recent studies within our group indicates a breed-based difference in dermal response to 1540 nm 0.8 millisecond laser pulses. Laser exposure to Yucatan Mini- Pigs (highly pigmented skin) and Yorkshire pigs (lightly pigmented skin) demonstrate statistical differences between the ED50's of the two breeds. Laser delivery is accomplished using an Er:Glass system producing 1540 nm of light at millisecond exposure times and in the range of 5 to 95 J/cm2. Dermal lesion development was evaluated for acute, 1 hour, and 24-hour post exposure presentation. Our data contradicts the theory that water absorption is the sole mechanism of dermal tissue damage observed from 1540 nm laser exposures, as skin chromophores appear to play a role in lesion development.

  15. Improved overlay metrology device correlation on 90-nm logic processes

    NASA Astrophysics Data System (ADS)

    Ueno, Atsushi; Tsujita, Kouichirou; Kurita, Hiroyuki; Iwata, Yasuhisa; Ghinovker, Mark; Poplawski, Jorge M.; Kassel, Elyakim; Adel, Mike E.

    2004-05-01

    Isolated and dense patterns were formed at process layers from gate through to back-end on wafers using a 90 nm logic device process utilizing ArF lithography under various lithography conditions. Pattern placement errors (PPE) between AIM grating and BiB marks were characterized for line widths varying from 1000nm to 140nm. As pattern size was reduced, overlay discrepancies became larger, a tendency which was confirmed by optical simulation with simple coma aberration. Furthermore, incorporating such small patterns into conventional marks resulted in significant degradation in metrology performance while performance on small pattern segmented grating marks was excellent. Finally, the data also show good correlation between the grating mark and specialized design rule feature SEM marks, with poorer correlation between conventional mark and SEM mark confirming that new grating mark significantly improves overlay metrology correlation with device patterns.

  16. Three-body dissociations: The photodissociation of dimethyl sulfoxide at 193 nm

    SciTech Connect

    Blank, D.A.; North, S.W.; Stranges, D.

    1997-04-01

    When a molecule with two equivalent chemical bonds is excited above the threshold for dissociation of both bonds, how the rupture of the two bonds is temporally coupled becomes a salient question. Following absorption at 193 nm dimethyl sulfoxide (CH{sub 3}SOCH{sub 3}) contains enough energy to rupture both C-S bonds. This can happen in a stepwise (reaction 1) or concerted (reaction 2) fashion where the authors use rotation of the SOCH{sub 3} intermediate prior to dissociation to define a stepwise dissociation: (1) CH{sub 3}SOCH{sub 3} {r_arrow} 2CH{sub 3} + SO; (2a) CH{sub 3}SOCH{sub 3} {r_arrow} CH{sub 3} + SOCH{sub 3}; and (2b) SOCH{sub 3} {r_arrow} SO + CH{sub 3}. Recently, the dissociation of dimethyl sulfoxide following absorption at 193 nm was suggested to involve simultaneous cleavage of both C-S bonds on an excited electronic surface. This conclusion was inferred from laser induced fluorescence (LIF) and resonant multiphoton ionization (2+1 REMPI) measurements of the internal energy content in the CH{sub 3} and SO photoproducts and a near unity quantum yield measured for SO. Since this type of concerted three body dissociation is very interesting and a rather rare event in photodissociation dynamics, the authors chose to investigate this system using the technique of photofragment translational spectroscopy at beamline 9.0.2.1. The soft photoionization provided by the VUV undulator radiation allowed the authors to probe the SOCH{sub 3} intermediate which had not been previously observed and provided good evidence that the dissociation of dimethyl sulfoxide primarily proceeds via a two step dissociation, reaction 2.

  17. Full-field imprinting of sub-40 nm patterns

    NASA Astrophysics Data System (ADS)

    Yeo, Jeongho; Kim, Hoyeon; Eynon, Ben

    2008-03-01

    Imprint lithography has been included on the ITRS Lithography Roadmap at the 32, 22 and 16 nm nodes. Step and Flash Imprint Lithography (S-FIL (R)) is a unique patterning method that has been designed from the beginning to enable precise overlay to enable multilevel device fabrication. A photocurable low viscosity resist is dispensed dropwise to match the pattern density requirements of the device, thus enabling patterning with a uniform residual layer thickness across a field and across multiple wafers. Further, S-FIL provides sub-50 nm feature resolution without the significant expense of multi-element projection optics or advanced illumination sources. However, since the technology is 1X, it is critical to address the infrastructure associated with the fabrication of imprint masks (templates). For sub-32 nm device manufacturing, one of the major technical challenges remains the fabrication of full-field 1x imprint masks with commercially viable write times. Recent progress in the writing of sub-40 nm patterns using commercial variable shape e-beam tools and non-chemically amplified resists has demonstrated a very promising route to realizing these objectives, and in doing so, has considerably strengthened imprint lithography as a competitive manufacturing technology for the sub-32nm node. Here we report the first imprinting results from sub-40 nm full-field patterns, using Samsung's current flash memory production device design. The fabrication of the imprint mask and the resulting critical dimension control and uniformity are discussed, along with image placement results. The imprinting results are described in terms of CD uniformity, etch results, and overlay.

  18. 32 nm imprint masks using variable shape beam pattern generators

    NASA Astrophysics Data System (ADS)

    Selinidis, Kosta; Thompson, Ecron; Schmid, Gerard; Stacey, Nick; Perez, Joseph; Maltabes, John; Resnick, Douglas J.; Yeo, Jeongho; Kim, Hoyeon; Eynon, Ben

    2008-05-01

    Imprint lithography has been included on the ITRS Lithography Roadmap at the 32, 22 and 16 nm nodes. Step and Flash Imprint Lithography (S-FIL ®) is a unique method that has been designed from the beginning to enable precise overlay for creating multilevel devices. A photocurable low viscosity monomer is dispensed dropwise to meet the pattern density requirements of the device, thus enabling imprint patterning with a uniform residual layer across a field and across entire wafers. Further, S-FIL provides sub-100 nm feature resolution without the significant expense of multi-element, high quality projection optics or advanced illumination sources. However, since the technology is 1X, it is critical to address the infrastructure associated with the fabrication of templates. For sub-32 nm device manufacturing, one of the major technical challenges remains the fabrication of full-field 1x templates with commercially viable write times. Recent progress in the writing of sub-40 nm patterns using commercial variable shape e-beam tools and non-chemically amplified resists has demonstrated a very promising route to realizing these objectives, and in doing so, has considerably strengthened imprint lithography as a competitive manufacturing technology for the sub 32nm node. Here we report the first imprinting results from sub-40 nm full-field patterns, using Samsung's current flash memory production device design. The fabrication of the template is discussed and the resulting critical dimension control and uniformity are discussed, along with image placement results. The imprinting results are described in terms of CD uniformity, etch results, and overlay.

  19. Full phase-shifting methodology for 65-nm node lithography

    NASA Astrophysics Data System (ADS)

    Pierrat, Christophe; Driessen, Frank A. J. M.; Vandenberghe, Geert

    2003-06-01

    A new methodology for completely phase-shifting a poly layout without creating local phase conflicts was proposed for lithographic techniques combining one phase-shifting mask and one binary mask exposure1. Critical and non-critical areas of the layout are identified and phase conflicts are avoided by splitting the shifter regions from non-critical areas to non-critical areas without crossing critical areas. The out-of-phase splits of the shifter regions are removed using the binary exposure. Simulation results and experimental data collected for 90nm technology node show no sign of process latitude loss around the areas where the shifters are split. The overlay latitude is commensurate with 90nm technology scanner requirements (tool to itself). Simulation work shows that the two exposures are balancing each other out of focus in the 45-degree cut regions thus ensuring large focus latitude. The focus latitude reported is larger than the main feature process latitude; this result was confirmed experimentally. A set of phase-shifting design rules commensurate with an aggressive 65nm node technology (140nm pitch) was put together. Under these conditions, we have identified certain types of cuts that should be avoided during the generation of the phase-shifting layout; this is primarily the case for cuts in "elbow" structures which exhibit limited process latitude. Other cuts like line-end cuts will have to be modified. In this case we have proposed a side cut when the line-end is facing a perpendicular line with a minimum spacing. Despite these restrictions, test structures for the 65nm technology node were successfully converted with no phase conflicts. Experimental verification done on test structures using a 0.75 NA, 193nm scanner demonstrates 0.33 k1 capability using the full phase methodology.

  20. Magnetic Behavior of Surface Nanostructured 50-nm Nickel Thin Films

    PubMed Central

    2010-01-01

    Thermally evaporated 50-nm nickel thin films coated on borosilicate glass substrates were nanostructured by excimer laser (0.5 J/cm2, single shot), DC electric field (up to 2 kV/cm) and trench-template assisted technique. Nanoparticle arrays (anisotropic growth features) have been observed to form in the direction of electric field for DC electric field treatment case and ruptured thin film (isotropic growth features) growth for excimer laser treatment case. For trench-template assisted technique; nanowires (70–150 nm diameters) have grown along the length of trench template. Coercive field and saturation magnetization are observed to be strongly dependent on nanostructuring techniques. PMID:21076670

  1. Cost-effective tunable 1310nm DWDM transmitter

    NASA Astrophysics Data System (ADS)

    Chorchos, Łukasz; Turkiewicz, Jarosław P.

    2015-09-01

    The growing demand for higher data rate transmissions in local and metropolitan area networks is main reason of developing effective and inexpensive transmission systems. In this paper, study about the possibility to realize 1310 nm tunable DWDM transmitter using commercially available low-cost DFB lasers is presented. Extensive DFB lasers characterization has been performed which led to establish relationships between laser current, operational temperature, emitted wavelength and power. An algorithm to find the laser settings for a desired wavelength grid has been proposed and tested. Generation of the 1310nm DWDM channels with frequency spacing between 120 and 240GHz has been demonstrated.

  2. Pseudomorphic Single-Quantum-Well Lasers Emit At 980 Nm

    NASA Technical Reports Server (NTRS)

    Larsson, Anders; Forouhar, Siamak; Cody, Jeffrey G.; Lang, Robert J.; Andrekson, Peter A.

    1992-01-01

    Narrow-stripe semiconductor lasers emitting at 980 nm include pseudomorphic In0.2Ga0.8As/GaAs/AlxGa1-xAs graded-index-of-refraction, separate-confinement-heterostructure single quantum well(GRINSCH SQW) with overlaid ridge waveguide. 980 nm chosen as one that yields most efficient pumping because there is no absorption in excited states at this wavelength. Suitable for pumping Er(Sup3+)-doped optical-fiber amplifiers in optical-fiber communication systems and optical phased-array ranging systems.

  3. Determination of transition probability for the 655-nm Tl line.

    NASA Astrophysics Data System (ADS)

    Karabourniotis, D.; Couris, S.; Damelincourt, J. J.

    Studies of high-pressure Hg-Tl I a.c. (50 Hz) arc plasmas have been used to verify the validity of Boltzmann statistics at the moment of maximum electron density (5 ms) by applying LTE criteria. For a known plasma temperature, the transition probability of the optically-thin 655-nm line of Tl was derived from emission measurements by using the self-reversed 535-nm line of Tl as reference [A655 = (3.74±0.37)×106s-1].

  4. Extension of 193 nm dry lithography to 45-nm half-pitch node: double exposure and double processing technique

    NASA Astrophysics Data System (ADS)

    Biswas, Abani M.; Li, Jianliang; Hiserote, Jay A.; Melvin, Lawrence S., III

    2006-10-01

    Immersion lithography and multiple exposure techniques are the most promising methods to extend lithography manufacturing to the 45nm node. Although immersion lithography has attracted much attention recently as a promising optical lithography extension, it will not solve all the problems at the 45-nm node. The 'dry' option, (i.e. double exposure/etch) which can be realized with standard processing practice, will extend 193-nm lithography to the end of the current industry roadmap. Double exposure/etch lithography is expensive in terms of cost, throughput time, and overlay registration accuracy. However, it is less challenging compared to other possible alternatives and has the ability to break through the κ I barrier (0.25). This process, in combination with attenuated PSM (att-PSM) mask, is a good imaging solution that can reach, and most likely go beyond, the 45-nm node. Mask making requirements in a double exposure scheme will be reduced significantly. This can be appreciated by the fact that the separation of tightly-pitched mask into two less demanding pitch patterns will reduce the stringent specifications for each mask. In this study, modeling of double exposure lithography (DEL) with att-PSM masks to target 45-nm node is described. In addition, mask separation and implementation issues of optical proximity corrections (OPC) to improve process window are studied. To understand the impact of OPC on the process window, Fourier analysis of the masks has been carried out as well.

  5. Precise Fabrication of Nanopores with Diameters of Sub-1 nm to 3 nm Using Multilevel Pulse-voltage Injection

    NASA Astrophysics Data System (ADS)

    Yanagi, Itaru; Akahori, Rena; Yokoi, Takahide; Takeda, Ken-Ichi

    2015-03-01

    To date, solid-state nanopores have been fabricated primarily through a focused-electronic beam via TEM. For mass production, however, a TEM beam is not suitable and an alternative fabrication method is required. Recently, a simple nanopore-fabrication method has been reported that is based on a dielectric breakdown phenomenon of a thin membrane. In this study, to stably fabricate nanopores with diameters of 1 to 2 nm (which is an essential size for distinguishing each nucleotide) via dielectric breakdown, a technique called multilevel pulse-voltage injection (MPVI) is proposed and demonstrated. MPVI uses pulse voltages for generating the nanopores, and the generation of the nanopores is verified by measuring the current through a membrane at low voltage. This method can generate nanopores with diameters of less than 1 nm in a 10-nm-thick Si3N4 membrane with a probability of 90%. The diameter of the generated nanopores can be widened to the desired diameters (up to 3 nm) with sub-nanometre precision. The mean effective thickness of the fabricated nanopores was 3.7 nm. These findings are derived from TEM images of the fabricated nanopores and analyses of ionic-current blockades during single-stranded DNA translocation.

  6. Analysis of line-and-space resist patterns with sub-20 nm half-pitch fabricated using high-numerical-aperture exposure tool of extreme ultraviolet lithography

    NASA Astrophysics Data System (ADS)

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

    2016-09-01

    The resolution of resist processes for extreme ultraviolet (EUV) lithography has been steadily improved and has reached the sub-20 nm half-pitch region. Currently, the resist materials capable of resolving 11 nm half-pitch line-and-space patterns are being developed in industrial fields. In this study, the line-and-space resist patterns with sub-20 nm half-pitches were fabricated using a high-numerical-aperture (NA) EUV exposure tool and analyzed by the Monte Carlo simulation. The scanning electron microscopy (SEM) images of resist patterns after their development were compared with the latent images calculated on the basis of the sensitization and reaction mechanisms of chemically amplified EUV resists. The approximate relationship between resist patterns and latent images was clarified for the sub-20 nm half-pitch region. For the realization of 11 nm half-pitch fabrication, the suppression of the stochastic effects in the development process is an important consideration.

  7. Characterization of single 1.8-nm Au nanoparticle attachments on AFM tips for single sub-4-nm object pickup

    PubMed Central

    2013-01-01

    This paper presents a novel method for the attachment of a 1.8-nm Au nanoparticle (Au-NP) to the tip of an atomic force microscopy (AFM) probe through the application of a current-limited bias voltage. The resulting probe is capable of picking up individual objects at the sub-4-nm scale. We also discuss the mechanisms involved in the attachment of the Au-NP to the very apex of an AFM probe tip. The Au-NP-modified AFM tips were used to pick up individual 4-nm quantum dots (QDs) using a chemically functionalized method. Single QD blinking was reduced considerably on the Au-NP-modified AFM tip. The resulting AFM tips present an excellent platform for the manipulation of single protein molecules in the study of single protein-protein interactions. PMID:24237663

  8. Detonation Wave Profiles in Plastic Bonded Explosives Measured using 1550 nm Heterodyne Velocimetry

    NASA Astrophysics Data System (ADS)

    Gustavsen, Rick

    2009-06-01

    We have measured detonation wave profiles in several triaminotrinitrobenzene (TATB) and cyclotetramethylene tetranitramine (HMX or octogen) based plastic bonded explosives using 1550 nm Heterodyne Velocimetry. (Heterodyne Velocimetry is also called Photon Doppler Velocimetry or PDV.) Planar detonations were produced by impacting the explosive with projectiles launched in a gas gun. Particle velocity wave profiles were measured at the mirror/interface of the explosive and either a LiF or PMMA window. Mirrors consisted of either a thin vapor deposited aluminum layer, or a 6 micron thick aluminum foil. Focusing and collimating light collection probes were used. Time-Frequency-Analysis of the fringe data was carried out using both Wavelet and Short-Time-Fourier-Transform (STFT) methods. With clean fringe data, good profiles can be obtained with a 1 ns full width half maximum (FWHM) analysis window (STFT) or about 3 to 4 oscillations in the wavelet. Some profiles, however, have a noisy character which is correlated with intensity fluctuations in the raw fringe data. Wave profiles show a ZND reaction zone structure with a single reaction in the HMX based explosives and both fast and slow reactions in the TATB based explosives.

  9. Kinetic analysis of the hydrolysis of methyl parathion using citrate-stabilized 10 nm gold nanoparticles.

    PubMed

    Nita, Rafaela; Trammell, Scott A; Ellis, Gregory A; Moore, Martin H; Soto, Carissa M; Leary, Dagmar H; Fontana, Jake; Talebzadeh, Somayeh F; Knight, D Andrew

    2016-02-01

    "Ligand-free" citrate-stabilized 10 nm gold nanoparticles (AuNPs) promote the hydrolysis of the thiophosphate ester methyl parathion (MeP) on the surface of gold as a function of pH and two temperature values. At 50 °C, the active surface gold atoms show catalytic turnover ∼4 times after 8 h and little turnover of gold surface atoms at 25 °C with only 40% of the total atoms being active. From Michaelis-Menten analysis, k(cat) increases between pH 8 and 9 and decreases above pH 9. A global analysis of the spectral changes confirmed the stoichiometric reaction at 25 °C and the catalytic reaction at 50 °C and mass spectrometry confirmed the identity of p-nitrophenolate (PNP) product. Additional decomposition pathways involving oxidation and hydrolysis independent of the formation of PNP were also seen at 50 °C for both catalyzed and un-catalyzed reactions. This work represents the first kinetic analysis of ligand-free AuNP catalyzed hydrolysis of a thiophosphate ester. PMID:26547026

  10. Imaging challenges in 20nm and 14nm logic nodes: hot spots performance in Metal1 layer

    NASA Astrophysics Data System (ADS)

    Timoshkov, V.; Rio, D.; Liu, H.; Gillijns, W.; Wang, J.; Wong, P.; Van Den Heuvel, D.; Wiaux, V.; Nikolsky, P.; Finders, J.

    2013-10-01

    The 20nm Metal1 layer, based on ARM standard cells, has a 2D design with minimum pitch of 64nm. This 2D design requires a Litho-Etch-Litho-Etch (LELE) double patterning. The whole design is divided in 2 splits: Me1A and Me1B. But solution of splitting conflicts needs stitching at some locations, what requires good Critical Dimension (CD) and overlay control to provide reliable contact between 2 stitched line ends. ASML Immersion NXT tools are aimed at 20 and 14nm logic production nodes. Focus control requirements become tighter, as existing 20nm production logic layouts, based on ARM, have about 50-60nm focus latitude and tight CD Uniformity (CDU) specifications, especially for line ends. IMEC inspected 20nm production Metal1 ARM standard cells with a Negative Tone Development (NTD) process using the Process Window Qualification-like technique experimentally and by Brion Tachyon LMC by simulations. Stronger defects were found thru process variations. A calibrated Tachyon model proved a good overall predictability capability for this process. Selected defects are likely to be transferred to hard mask during etch. Further, CDU inspection was performed for these critical features. Hot spots showed worse CD uniformity than specifications. Intra-field CDU contribution is significant in overall CDU budget, where reticle has major impact due to high MEEF of hot spots. Tip-to-Tip and tip-to-line hot spots have high MEEF and its variation over the field. Best focus variation range was determined by best focus offsets between hot spots and its variation within the field.

  11. Can Homojunction Tunnel FETs Scale Below 10 nm?

    NASA Astrophysics Data System (ADS)

    Ilatikhameneh, Hesameddin; Klimeck, Gerhard; Rahman, Rajib

    2016-01-01

    The main promise of tunnel FETs (TFETs) is to enable supply voltage ($V_{DD}$) scaling in conjunction with dimension scaling of transistors to reduce power consumption. However, reducing $V_{DD}$ and channel length ($L_{ch}$) typically deteriorates the ON- and OFF-state performance of TFETs, respectively. Accordingly, there is not yet any report of a high perfor]mance TFET with both low V$_{DD}$ ($\\sim$0.2V) and small $L_{ch}$ ($\\sim$6nm). In this work, it is shown that scaling TFETs in general requires scaling down the bandgap $E_g$ and scaling up the effective mass $m^*$ for high performance. Quantitatively, a channel material with an optimized bandgap ($E_g\\sim1.2qV_{DD} [eV]$) and an engineered effective mass ($m*^{-1}\\sim40 V_{DD}^{2.5} [m_0^{-1}]$) makes both $V_{DD}$ and $L_{ch}$ scaling feasible with the scaling rule of $L_{ch}/V_{DD}=30~nm/V$ for $L_{ch}$ from 15nm to 6nm and corresponding $V_{DD}$ from 0.5V to 0.2V.

  12. 78 FR 66982 - Santa Clara Pueblo Disaster #NM-00039

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-07

    ... ADMINISTRATION Santa Clara Pueblo Disaster NM-00039 AGENCY: U.S. Small Business Administration. ACTION: Notice... for the Santa Clara Pueblo (FEMA- 4151-DR), dated 10/29/2013. Incident: Severe Storms and Flooding... disaster: Primary Areas: Santa Clara Pueblo. The Interest Rates are: Percent For Physical Damage:...

  13. Ca II 854.2 nm BISECTORS AND CIRCUMFACULAR REGIONS

    SciTech Connect

    Pietarila, A.; Harvey, J. W.

    2013-02-20

    Active regions appear bright in Ca II 854.2 nm line core intensity while the surrounding areas, referred to as circumfacular regions, are darker than the active region or the quiet Sun. We use Synoptic Optical Long-term Investigations of the Sun Vector Spectromagnetograph Ca II 854.2 nm data (photospheric and chromospheric full disk magnetograms as well as high spectral resolution Stokes I and V profiles) to study the connection between magnetic canopies, circumfacular regions, and Ca II 854.2 nm bisector amplitudes (spans). The line bisector amplitude is reduced in circumfacular regions, where the 3 minute period power in chromospheric H{alpha} intensity oscillations is also reduced relative to the surrounding quiet Sun. The latter is consistent with magnetic canopies in circumfacular regions suppressing upward propagating steepening acoustic waves. Our results provide further strong evidence for shock waves as the cause of the inverse C-shaped bisector and explain the observed solar cycle variation of the shape and amplitude of Sun-as-a-star Ca II 854.2 nm bisectors.

  14. Surface Photometry of the Southern Milky Way at 170 NM

    NASA Astrophysics Data System (ADS)

    Hansen, J.; Schlosser, W.; Schmidtobreick, L.; Koczet, P.

    As part of the D2-Space-Shuttle-Mission in 1993, the GAUSS-Camera has obtained photographic images of the Milky Way in various passbands in the Ultraviolet. Each film covers an area of the sky of about 140^\\circ. Six images were obtained at 170 nm, but only three of them could be used. The calibration has been done using the catalogued intensities of stars and transforming them into surface brightnesses. Then the stars on the images have been filtered out and the Shuttle-Glow has been eliminated. The images finally have been transformed into maps of the Milky Way in galactic coordinates l, b. These maps cover the Milky Way between the Galactic Center and Vela (360^\\circ <= l <= 270^\\circ, - -25^\\circ <= b <= 35^\\circ) and include dark clouds, reflection nebulae and bright open clusters. They are a perfect tool to investigate the distribution of these objects and therefore the global structure of the Milky Way. The image of the Milky Way at 170 nm is heavily dominated by interstellar extinction, leading to high intensity gradients all over the galactic plane. The images at 217 nm and 280 nm, also obtained by the GAUSS-Camera, and previous photometries taken in U, B, V and R have been used for comparison.

  15. VUV spectrophotometry for photomasks characterization at 193 nm

    NASA Astrophysics Data System (ADS)

    Yang, Minghong; Leiterer, Jork; Gatto, Alexandre; Kaiser, Norbert; Höllein, Ingo; Teuber, Silvio; Bubke, Karsten

    2005-10-01

    This paper intends to develop a measurement system to characterize photomasks for 193 nm lithography applications. Based on the VUV spectrophotometer at the Fraunhofer IOF institute, some modifications have been addressed to fulfil these special measurements. Characterizations on photomasks have been successfully carried out, which show good correlations to simulations.

  16. Scatterometry for EUV lithography at the 22-nm node

    NASA Astrophysics Data System (ADS)

    Bunday, Benjamin; Vartanian, Victor; Ren, Liping; Huang, George; Montgomery, Cecilia; Montgomery, Warren; Elia, Alex; Liu, Xiaoping

    2011-03-01

    Moore's Law continues to drive improvements to lithographic resolution to increase integrated circuit transistor density, improve performance, and reduce cost. For the 22 nm node and beyond, extreme ultraviolet lithography (EUVL) is a promising technology with λ=13.5 nm, a larger k1 value and lower cost of ownership than other available technologies. For small feature sizes, process control will be increasingly challenging, as small features will create measurement uncertainties, yet with tighter specifications. Optical scatterometry is a primary candidate metrology for EUV lithography process control. Using simulation and experimental data, this work will explore scatterometry's application to a typical lithography process being used for EUV development, which should be representative of lithography processes that will be utilized for EUV High Volume manufacturing (HVM). EUV lithography will be performed using much thinner photoresist thicknesses than were used at the 248nm or 193nm lithography generations, and will probably include underlayers for adhesion improvement; these new processes conditions were investigated in this metrological study.

  17. Inorganic immersion fluids for ultrahigh numerical aperture 193 nm lithography

    NASA Astrophysics Data System (ADS)

    Zhou, Jianming; Fan, Yongfa; Bourov, Anatoly; Smith, Bruce W.

    2006-05-01

    Immersion lithography has become attractive since it can reduce critical dimensions by increasing numerical aperture (NA) beyond unity. Among all the candidates for immersion fluids, those with higher refractive indices and low absorbance are desired. Characterization of the refractive indices and absorbance of various inorganic fluid candidates has been performed. To measure the refractive indices of these fluids, a prism deviation angle method was developed. Several candidates have been identified for 193 nm application with refractive indices near 1.55, which is approximately 0.1 higher than that of water at this wavelength. Cauchy parameters of these fluids were generated and approaches were investigated to tailor the fluid absorption edges to be close to 193 nm. The effects of these fluids on photoresist performance were also examined with 193 nm immersion lithography exposure at various NAs. Half-pitch 32 nm lines were obtained with phosphoric acid as the immersion medium at 1.5 NA. These fluids are potential candidates for immersion lithography technology.

  18. Blue light (470 nm) effectively inhibits bacterial and fungal growth

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The activity of blue light (470nm) alone on (1) bacterial viability, and (2) with a food grade photosensitizer on filamentous fungal viability, was studied. Suspensions of the bacteria Leuconostoc mesenteroides (LM), Bacillus atrophaeus (BA), and Pseudomonas aeruginosa (PA) were prepared and aliquo...

  19. High average power, narrow band 248 nm alexandrite laser system

    SciTech Connect

    Kuper, J.W.; Chin, T.C.; Papanestor, P.A.

    1994-12-31

    A compact line-narrowed 248 nm solid state laser source operating at 15 mJ {at} 100 Hz PRF was demonstrated. Constraints due to thermal loading of components were addressed. Tradeoffs between pulse energy and repetition rate were investigated. A method for overcoming thermal dephasing in the THG material was achieved by scanning a slab shaped crystal.

  20. Encapsulated inorganic resist technology applied to 157-nm lithography

    NASA Astrophysics Data System (ADS)

    Fedynyshyn, Theodore H.; Sinta, Roger F.; Sworin, Michael; Goodman, Russell B.; Doran, Scott P.; Sondi, I.; Matijevic, Egon

    2001-08-01

    In order to increase plasma etch selectivity in traditional single layer organic resists SiO2 nanoparticles have been added to typical 248nm resist formulations. Formulation modifications are necessary due to the dissolution acceleration effect of the particles. Surface functionalization of the nanoparticle surfaces with organic groups lessens this effect and allows the inclusion of acid labile groups. This allows for a wider formulation window and limits unexposed film thickness losses (UFTL). Both t- butyl ester groups and poly(t-butyl acrylate) have been used to achieve this effect. Encapsulated inorganic resist technology (EIRT) can be used as a single layer hard mask compatible with existing resist processing steps and replace complex and costly multilevel resist approaches. Lithogrpahic evaluations have been performed with electron beam, and with 248nm and 157nm projection systems. Greater transparency at 157nm is achieved by the addition of these materials, thus enabling the use of thicker films. High resolution imaging is demonstrated at these wavelengths.

  1. Photoabsorption cross section of OD at 115-180 nm

    NASA Technical Reports Server (NTRS)

    Nee, J. B.; Lee, L. C.

    1984-01-01

    The photoabsorption cross sections of OD in the 115-180 nm region were measured. The OD radicals were produced from a pulsed discharge in a mixture containing a trace of D2O in a few Torr of argon. Results are compared with the photoabsorption of OH previously measured.

  2. 78 FR 67210 - Santa Clara Pueblo Disaster #NM-00038

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-08

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Santa Clara Pueblo Disaster NM-00038 AGENCY: U.S. Small Business Administration. ACTION: Notice...: Submit completed loan applications to: U.S. Small Business Administration, Processing and...

  3. 77 FR 62481 - Radio Broadcasting Services; Crownpoint, NM

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-15

    ... COMMISSION 47 CFR Part 73 Radio Broadcasting Services; Crownpoint, NM AGENCY: Federal Communications....415 and 1.420. List of Subjects in 47 CFR Part 73 Radio, Radio broadcasting. Federal Communications... preamble, the Federal Communications Commission proposes to amend 47 CFR Part 73 as follows: PART...

  4. EUV optical design for 100 nm CD imaging system

    SciTech Connect

    Sweeney, D.W.; Hudyma, R.; Chapman, H.B.; Shafer, D.

    1998-04-09

    The imaging specifications for extreme ultraviolet lithography (EUVL) projection optics parallel those of other optical lithographies. Specifications are scaled to reflect the 100 nm critical dimension for the first generation EUVL systems. The design being fabricated for the Engineering Test Stand, an EUVL alpha tool, consists of a condenser with six channels to provide an effective partial coherence factor of 0.7. The camera contains four mirrors; three of the mirrors are aspheres and the fourth is spherical. The design of the optical package has been constrained so that the angles of incidence and the variations in the angle of incidence of all rays allow for uniform multilayer coatings. The multilayers introduce a slight shift in image position and magnification. We have shown that a system aligned with visible light is also aligned at 13.4 nm. Each mirror must be fabricated with an RMS figure error of less than 0.25 nm and better than 0.2 nm RMS roughness. Optical surfaces that exceed each of these specifications individually have been fabricated. The success of EUVL requires that these specifications be met simultaneously.

  5. A novel double patterning approach for 30nm dense holes

    NASA Astrophysics Data System (ADS)

    Hsu, Dennis Shu-Hao; Wang, Walter; Hsieh, Wei-Hsien; Huang, Chun-Yen; Wu, Wen-Bin; Shih, Chiang-Lin; Shih, Steven

    2011-04-01

    Double Patterning Technology (DPT) was commonly accepted as the major workhorse beyond water immersion lithography for sub-38nm half-pitch line patterning before the EUV production. For dense hole patterning, classical DPT employs self-aligned spacer deposition and uses the intersection of horizontal and vertical lines to define the desired hole patterns. However, the increase in manufacturing cost and process complexity is tremendous. Several innovative approaches have been proposed and experimented to address the manufacturing and technical challenges. A novel process of double patterned pillars combined image reverse will be proposed for the realization of low cost dense holes in 30nm node DRAM. The nature of pillar formation lithography provides much better optical contrast compared to the counterpart hole patterning with similar CD requirements. By the utilization of a reliable freezing process, double patterned pillars can be readily implemented. A novel image reverse process at the last stage defines the hole patterns with high fidelity. In this paper, several freezing processes for the construction of the double patterned pillars were tested and compared, and 30nm double patterning pillars were demonstrated successfully. A variety of different image reverse processes will be investigated and discussed for their pros and cons. An economic approach with the optimized lithography performance will be proposed for the application of 30nm DRAM node.

  6. Gain measurements at 5 nm in nickel-like ytterbium

    SciTech Connect

    MacGowan, B.J.; Bourgade, J.L.; Combis, P.; Keane, C.J.; Louis-Jacquet, M.; Matthews, D.L.; Naccache, D.; Stone, G.; Thiell, G.; Whelan, D.A.

    1988-03-01

    Soft x-ray gain has been demonstrated at 5.03 nm within a laser produced plasma of Ni-like ytterbium. Experiments will also be described with higher Z Ni-like ions which can produce even shorter wavelength x-ray laser transition. 3 refs.

  7. 78 FR 61999 - New Mexico Disaster #NM-00037

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-10

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION New Mexico Disaster NM-00037 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY... State of New Mexico (FEMA- 4148-DR), dated 09/30/2013. Incident: Severe Storms and Flooding....

  8. 77 FR 41874 - New Mexico Disaster #NM-00025

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-16

    ... ADMINISTRATION New Mexico Disaster NM-00025 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a notice of an Administrative declaration of a disaster for the State of New Mexico dated 07/09... adversely affected by the disaster: Primary Counties: Lincoln. Contiguous Counties: New Mexico: Chaves,...

  9. 77 FR 63409 - New Mexico Disaster Number NM-00029

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-16

    ... ADMINISTRATION New Mexico Disaster Number NM-00029 AGENCY: U.S. Small Business Administration. ACTION: Amendment... Assistance Only for the State of New Mexico (FEMA-4079-DR), dated 08/24/2012. Incident: Flooding. Incident... Non-Profit organizations in the State of NEW MEXICO, dated 08/24/2012, is hereby amended to...

  10. 77 FR 47907 - New Mexico Disaster #NM-00025

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-10

    ... ADMINISTRATION New Mexico Disaster NM-00025 AGENCY: U.S. Small Business Administration. ACTION: Amendment 1. SUMMARY: This is an amendment of the Administrative declaration of a disaster for the State of NEW MEXICO...'s declaration for the State of New Mexico, dated 07/09/2012 is hereby amended to establish...

  11. 78 FR 66982 - New Mexico Disaster #NM-00035

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-07

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION New Mexico Disaster NM-00035 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY... State of New Mexico (FEMA- 4152-DR), dated 10/29/2013. Incident: Severe storms, flooding, and...

  12. 77 FR 55523 - New Mexico Disaster #NM-00029

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-10

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION New Mexico Disaster NM-00029 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY... State of New Mexico (FEMA- 4079-DR), dated 08/24/2012. Incident: Flooding. Incident Period:...

  13. 76 FR 81553 - New Mexico Disaster Number NM-00024

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-28

    ... ADMINISTRATION New Mexico Disaster Number NM-00024 AGENCY: U.S. Small Business Administration. ACTION: Amendment... Assistance Only for the State of New Mexico (FEMA-4047-DR), dated 11/23/2011. Incident: Flooding. Incident... Non-Profit organizations in the State of New Mexico, dated 11/23/2011, is hereby amended to...

  14. 76 FR 18289 - New Mexico Disaster #NM-00020

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-01

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION New Mexico Disaster NM-00020 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY... State of New Mexico (FEMA- 1962-DR), dated 03/24/2011. Incident: Severe Winter Storm and Extreme...

  15. 76 FR 76801 - New Mexico Disaster #NM-00024

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-08

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION New Mexico Disaster NM-00024 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY... State of New Mexico (FEMA- 4047-DR), dated 11/23/2011. Incident: Flooding. Incident Period:...

  16. 78 FR 72141 - New Mexico Disaster Number NM-00037

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-02

    ... ADMINISTRATION New Mexico Disaster Number NM-00037 AGENCY: U.S. Small Business Administration. ACTION: Amendment... Assistance Only for the State of New Mexico (FEMA-4148-DR), dated 09/30/2013. Incident: Severe Storms and... Private Non-Profit organizations in the State of New Mexico, dated 09/30/2013, is hereby amended...

  17. 76 FR 2431 - New Mexico Disaster #NM-00016

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-13

    ... ADMINISTRATION New Mexico Disaster NM-00016 AGENCY: U.S. Small Business Administration. ACTION: Amendment 1... Only for the State of New Mexico (FEMA-1936-DR), dated 09/13/2010. Incident: Severe Storms and Flooding... Private Non-Profit organizations in the State of NEW MEXICO, dated 09/13/2010, is hereby amended...

  18. 75 FR 57538 - New Mexico Disaster # NM-00016

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-21

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION New Mexico Disaster NM-00016 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY... State of New Mexico (FEMA- 1936-DR), dated 09/13/2010. Incident: Severe Storms and Flooding....

  19. 78 FR 73581 - New Mexico Disaster Number NM-00035

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-06

    ... ADMINISTRATION New Mexico Disaster Number NM-00035 AGENCY: U.S. Small Business Administration. ACTION: Amendment... Assistance Only for the State of New Mexico (FEMA-4152-DR), dated 10/29/2013. Incident: Severe Storms... disaster declaration for Private Non-Profit organizations in the State of New Mexico, dated 10/29/2013,...

  20. Nucleation and reaction rates controlled by local reaction volume and reaction-induced stress - spinel layer growth as an example

    NASA Astrophysics Data System (ADS)

    Götze, Lutz C.; Milke, Ralf; Dohmen, Ralf; Wirth, Richard

    2014-05-01

    We observed the growth of spinel sensu stricto (MgAl2O4) between periclase (MgO) and corundum (Al2O3) in thin films deposited by the pulsed laser deposition method on crystallographically oriented single crystal substrates. The starting samples consisted of cut and ultra polished single crystals of either corundum (parallel (0001)) or periclase (parallel (111)) and an amorphous source layer of the respective reactant that in the very first stages of the experiments became polycrystalline. The cutting direction in the substrate minerals ensures that the substrate phases start to react along their close-packed hexagonal oxygen layers which allows topotactical growth of the newly formed spinel. The entire layer setup on the substrate crystals was only a few 100 nm thick. The growth of these spinel product layers was monitored in-situ using a heating attachment and synchrotron X-ray diffraction. From the reacted samples we took electron transparent foils by the focused ion beam method and analysed them ex-situ by TEM. At 1000°C we found a difference in spinel growth rate between one and two orders of magnitude between the two substrates, all other parameters held constant. At 900 and 1000 °C spinel had formed after one hour by 0.004 nm/s (900°C) and 0.034 nm/s (1000°C) on corundum substrate, while on periclase substrate the reaction had gone completely through the Al2O3 source layer transforming it to spinel by at least 15-30 times higher reaction rates (boundary values) and probably even faster. At 800°C no reaction occurred between periclase layers and corundum single crystals, whereas spinel crystallized at a (linearized) rate of 46 nm/h on periclase single crystals. We explain our findings by the local reaction volume at the periclase-corundum interface. Many studies (including this one) have established that spinel grows by cation exchange in a rather immobile oxygen sublattice. This mechanism implies a negative volume change at the Sp-Per interface (by -13

  1. Anaphylactic reactions to cinoxacin.

    PubMed Central

    Stricker, B. H.; Slagboom, G.; Demaeseneer, R.; Slootmaekers, V.; Thijs, I.; Olsson, S.

    1988-01-01

    During 1981 to mid-1988 three cases of anaphylactic shock after treatment with the quinolone derivative cinoxacin were reviewed by the Netherlands Centre for Monitoring of Adverse Reactions to Drugs and 17 cases of an anaphylactic type of reaction notified to the World Health Organisation Collaborating Centre for International Drug Monitoring. In five out of six patients for whom data were available the reaction began shortly after taking a single capsule of a second or next course of treatment. Cinoxacin is related to nalidixic acid, and one patient previously treated with that agent subsequently had an anaphylactoid reaction to cinoxacin and later developed a skin reaction to nalidixic acid. There were no deaths, and patients treated as an emergency with plasma expanders or with adrenaline and corticosteroids generally recovered promptly and uneventfully. In view of the potentially fatal consequences of anaphylactic reactions to cinoxacin and other quinolones doctors should take care when prescribing these drugs. PMID:3147004

  2. Reactions to radiocontrast media.

    PubMed

    Hong, Sandra J; Wong, Johnson T; Bloch, Kurt J

    2002-01-01

    Adverse reactions to radiocontrast media (RCM) occur unexpectedly and may be life-threatening. This article describes an anaphylactoid reaction (AR) in one patient. The term AR refers to a syndrome clinically similar to anaphylaxis, but these reactions are independent of immunoglobulin E antibody-mediated mast cell or basophil degranulation. This article briefly reviews the literature regarding RCMs and types of reactions to RCM. The risk factors for AR to RCM infusions will be discussed along with current concepts of the pathogenesis of RCM-induced ARs. This article also describes the therapeutic management of patients who have had a previous adverse reaction to RCM and provides an approach to patients who have breakthrough reactions despite adequate premedication, but require additional radiographic studies. PMID:12476546

  3. Noncanonical Reactions of Flavoenzymes

    PubMed Central

    Sobrado, Pablo

    2012-01-01

    Enzymes containing flavin cofactors are predominantly involved in redox reactions in numerous cellular processes where the protein environment modulates the chemical reactivity of the flavin to either transfer one or two electrons. Some flavoenzymes catalyze reactions with no net redox change. In these reactions, the protein environment modulates the reactivity of the flavin to perform novel chemistries. Recent mechanistic and structural data supporting novel flavin functionalities in reactions catalyzed by chorismate synthase, type II isopentenyl diphosphate isomerase, UDP-galactopyranose mutase, and alkyl-dihydroxyacetonephosphate synthase are presented in this review. In these enzymes, the flavin plays either a direct role in acid/base reactions or as a nucleophile or electrophile. In addition, the flavin cofactor is proposed to function as a “molecular scaffold” in the formation of UDP-galactofuranose and alkyl-dihydroxyacetonephosphate by forming a covalent adduct with reaction intermediates. PMID:23203060

  4. Mechanisms in Knockout Reactions

    NASA Astrophysics Data System (ADS)

    Bazin, D.; Charity, R. J.; de Souza, R. T.; Famiano, M. A.; Gade, A.; Henzl, V.; Henzlova, D.; Hudan, S.; Lee, J.; Lukyanov, S.; Lynch, W. G.; McDaniel, S.; Mocko, M.; Obertelli, A.; Rogers, A. M.; Sobotka, L. G.; Terry, J. R.; Tostevin, J. A.; Tsang, M. B.; Wallace, M. S.

    2009-06-01

    We report the first detailed study of the relative importance of the stripping and diffraction mechanisms involved in nucleon knockout reactions, by the use of a coincidence measurement of the residue and fast proton following one-proton knockout reactions. The measurements used the S800 spectrograph in combination with the HiRA detector array at the NSCL. Results for the reactions Be9(C9,B8+X)Y and Be9(B8,Be7+X)Y are presented and compared with theoretical predictions for the two reaction mechanisms calculated using the eikonal model. The data show a clear distinction between the stripping and diffraction mechanisms and the measured relative proportions are very well reproduced by the reaction theory. This agreement adds support to the results of knockout reaction analyses and their applications to the spectroscopy of rare isotopes.

  5. Cryogenic Lifetime Studies of 130 nm and 65 nm CMOS Technologies for High-Energy Physics Experiments

    SciTech Connect

    Hoff, James R.; Deptuch, G. W.; Wu, Guoying; Gui, Ping

    2015-06-04

    The Long Baseline Neutrino Facility intends to use unprecedented volumes of liquid argon to fill a time projection chamber in an underground facility. Research is under way to place the electronics inside the cryostat. For reasons of efficiency and economics, the lifetimes of these circuits must be well in excess of 20 years. The principle mechanism for lifetime degradation of MOSFET devices and circuits operating at cryogenic temperatures is hot carrier degradation. Choosing a process technology that is, as much as possible, immune to such degradation and developing design techniques to avoid exposure to such damage are the goals. This, then, requires careful investigation and a basic understanding of the mechanisms that underlie hot carrier degradation and the secondary effects they cause in circuits. In this work, commercially available 130 nm and 65 nm nMOS transistors operating at cryogenic temperatures are investigated. Our results show that both technologies achieve the lifetimes required by the experiment. Minimal design changes are necessary in the case of the 130 nm process and no changes whatsoever are necessary for the 65 nm process.

  6. Sleeve reaction chamber system

    SciTech Connect

    Northrup, M. Allen; Beeman, Barton V.; Benett, William J.; Hadley, Dean R.; Landre, Phoebe; Lehew, Stacy L.; Krulevitch, Peter A.

    2009-08-25

    A chemical reaction chamber system that combines devices such as doped polysilicon for heating, bulk silicon for convective cooling, and thermoelectric (TE) coolers to augment the heating and cooling rates of the reaction chamber or chambers. In addition the system includes non-silicon-based reaction chambers such as any high thermal conductivity material used in combination with a thermoelectric cooling mechanism (i.e., Peltier device). The heat contained in the thermally conductive part of the system can be used/reused to heat the device, thereby conserving energy and expediting the heating/cooling rates. The system combines a micromachined silicon reaction chamber, for example, with an additional module/device for augmented heating/cooling using the Peltier effect. This additional module is particularly useful in extreme environments (very hot or extremely cold) where augmented heating/cooling would be useful to speed up the thermal cycling rates. The chemical reaction chamber system has various applications for synthesis or processing of organic, inorganic, or biochemical reactions, including the polymerase chain reaction (PCR) and/or other DNA reactions, such as the ligase chain reaction.

  7. Metal-mullite reactions

    SciTech Connect

    Loehman, R.E.; Tomsia, A.P.

    1993-11-01

    Mullite was reacted with pure Al and with Ti or Zr dissolved in Ag-Cu eutectic alloys at 1100 C in Ar. Analysis of the Ti and Zr-containing specimens showed reaction zones with compositions of Ti{sub 50}Cu{sub 3O}O{sub 20} and ZrO{sub 2}, respectively. The Al-mullite specimen showed much more extensive penetration into the ceramic and a more diffuse reaction zone than the other two systems. Al{sub 2}O{sub 3} and Si were the main reaction products for Al-mullite reaction.

  8. Double exposure technique for 45nm node and beyond

    NASA Astrophysics Data System (ADS)

    Hsu, Stephen; Park, Jungchul; Van Den Broeke, Douglas; Chen, J. Fung

    2005-11-01

    The technical challenges in using F2 lithography for the 45nm node, along with the insurmountable difficulties in EUV lithography, has driven the semiconductor chipmaker into the low k1 lithography era under the pressure of ever decreasing feature sizes. Extending lithography towards lower k1 puts heavy demand on the resolution enhancement technique (RET), exposure tool, and the need for litho friendly design. Hyper numerical aperture (NA) exposure tools, immersion, and double exposure techniques (DET's) are the promising methods to extend lithography manufacturing to the 45nm node at k1 factors below 0.3. Scattering bars (SB's) have become an integral part of the lithography process as chipmakers move to production at ever lower k1 factors. To achieve better critical dimension (CD) control, polarization is applied to enhance the image contrast in the preferential imaging orientation, which increases the risk of SB printability. The optimum SB width is approximately (0.20 ~ 0.25)*(λ/NA). When the SB width becomes less than the exposure wavelength on the 4X mask, Kirchhoff's scalar theory under predicts the SB intensity. The optical weighting factor of the SB increases (Figure 1b) and the SB's become more susceptible to printing. Meanwhile, under hyper NA conditions, the effectiveness of "subresolution" SB's is significantly diminished. A full-sized scattering bars (FSB) scheme becomes necessary. Double exposure methods, such as using ternary 6% attenuated PSM (attPSM) for DDL, are good imaging solutions that can reach and likely go beyond the 45nm node. Today DDL, using binary chrome masks, is capable of printing 65 nm device patterns. In this work, we investigate the use of DET with 6% attPSM masks to target 45nm node device. The SB scalability and printability issues can be taken cared of by using "mutual trimming", i.e., with the combined energy from the two exposures. In this study, we share our findings of using DET to pattern a 45nm node device design with

  9. Top surface imaging through vapor phase silylation for 193 nm lithography

    NASA Astrophysics Data System (ADS)

    Somervell, Mark Howell

    The microelectronics industry has experienced enormous growth in the recent past. Most of this growth can be attributed to the constantly decreasing size of transistors and integrated circuits. The shrinkage of these devices has been made possible through advances in the photolithographic processes used to print circuit patterns on silicon wafers. Currently, the most advanced photolithographic processes use 193 nm exposure sources, and a variety of lithographic technologies have been investigated for use at this wavelength. This dissertation describes the application of atop surface imaging (TSI) process to 193 nm photolithography. The TSI scheme studied here uses light to modulate the reactivity of a photoresist film toward a silylating agent. Only the top surface of the photoresist is exposed so that polymers having high absorbance at the actinic wavelength can be used. The silylation reaction selectively incorporates silicon into the exposed regions of the photoresist while leaving the unexposed portions unchanged. An oxygen reactive ion etch (RIE) process is then used to transfer the silylated image at the top of the resist through the full photoresist thickness to generate a three-dimensional pattern. Two polymer platforms were studied for use in this system. The first, based on a protected poly(p-hydroxystyrene) resin, was optimized by incorporating different chemical components into the resist, exploring the use of novel silylating agents, and developing RIE processes especially for this photoresist resin. This system is capable of printing high resolution features at relatively low exposure doses, but these features have a large degree of line edge roughness (LER). Experiments indicate that the LER is caused by both the extremely high optical density of this polymer at 193 nm and the low glass transition temperature of the silylated material. As a second platform, certain alicyclic polymers offering both improved transparency and increased glass transition

  10. Double exposure for the contact layer of the 65-nm node

    NASA Astrophysics Data System (ADS)

    Owe-Yang, Dah-Chung; Yu, S. S.; Chen, Harrison; Chang, C. Y.; Ho, Bang-Chein; Lin, John C.; Lin, Burn J.

    2005-05-01

    The critical dimension (CD) of contact holes for the 65-nm application specific integrated circuit (ASIC) is 100 nm according to the 2002 update of the International Technology Roadmap for Semiconductors. The common through-pitch depth of focus (DOF) of such contact holes is very small using the current ArF exposure tool. High-numerical-aperture (NA) ArF exposure tools are not expected to improve the common DOF that scales by the square of the numerical half aperture. High-transmission attenuated phase-shifting masks increase the DOF of isolated contact holes. Off-axis illumination such as annular or quadrupole illumination improves the DOF of dense contact holes. Nonetheless, both the isolated and the dense contact holes need to be printed within spec on logic circuit. To delineate 100-nm contact holes at several different pitches, we proposed the pack-and-unpack (PAU) process which employs double exposures. First, dummy holes are added to the surroundings of isolated contact holes facilitating the patterning of the resultant dense pattern with a resolution enhancement technique that favors dense contact holes. For example, dense holes are packed to 180-nm pitch and imaged with high-NA lens setting and quadrupole illumination. Then, the second image is used to open the desired holes or block the dummy contact holes. The purpose of this study was to develop new methods and new materials for the patterning of the second image. Three approaches were investigated. The first approach was forming an isolation layer to protect the first image; second, applying UV curing to harden the first image; third, using alcohol-based resists to pattern the second image. Among those three approaches of printing the second image, using resist in alcohols is the most convenient method. Even though the CD control of the second image is not so critical, resolution and process window of resists may need further improvement for 45-nm node and below. Using the second approach allows

  11. Photodissociation of vinyl cyanide at 193 nm: Nascent product distributions of the molecular elimination channels

    SciTech Connect

    Wilhelm, Michael J.; Nikow, Matthew; Letendre, Laura; Dai Hailung

    2009-01-28

    The photodissociation dynamics of vinyl cyanide (H{sub 2}CCHCN, acrylonitrile) and deuterated vinyl cyanide (D{sub 2}CCDCN) at 193 nm are examined using time-resolved Fourier transform infrared emission spectroscopy. Prior photofragment translational spectroscopy studies [D. A. Blank et al., J. Chem. Phys. 108, 5784 (1998)] of the dissociation have observed the presence of four main dissociation channels; two molecular and two radical in nature. However, with the exception of a<0.01 quantum yield determined for the CN radical loss channel, the branching ratios of the remaining three elimination channels were not measured. The time-resolved emission spectra, including those from the deuterated samples, revealed the presence of acetylene, hydrogen cyanide (HCN), as well as the energetically less stable isomer hydrogen isocyanide (HNC). Acetylene is found in two distinct energetic distributions, suggesting that both three- and four-centered elimination reactions are occurring significantly in the dissociation. In contrast to prior ab initio studies that have suggested the dominant nature of the three-center elimination of molecular hydrogen (H{sub 2}) and cyanovinylidene (:C=CHCN), we find this reaction channel to be of little importance as there is no evidence to support any significant presence of rovibrationally excited cyanoacetylene. Spectral modeling of the product distributions allows for the first experimental determination of the relative occurrence of the three-centered (resulting in HCN+vinylidene) versus four-centered (HNC+acetylene) elimination channels as 3.34 to 1.00, in contrast to the previously calculated value of 126:1. Rice-Ramsperger-Kassel-Marcus analysis depicts that the transition state energy of the four-centered reaction should be about 10 kcal mole{sup -1} lower than the three-centered reaction.

  12. Laser-induced damage measurements with 266-nm pulses

    NASA Astrophysics Data System (ADS)

    Deaton, T. F.; Smith, W. L.

    1980-07-01

    Results of a survey of laser-induced damage thresholds for optical components at 266-nm are reported. The thresholds were measured at two pulse durations; 0.150 ns and 1.0 ns. The 30 samples tested include four commercial dielectric reflectors, three metallic reflectors, two anti-reflection films, a series of eight half-wave oxide and fluoride films, and twelve bare surfaces (fluoride crystals, silica, sapphire, BK-7 glass, cesium dideuterium arsenate and potassium dihydrogen phosphate). The 266-nm pulses were obtained by frequency-quadrupling a Nd:YAG, glass laser. Equivalent plane imagery and calorimetry were used to measure the peak fluence of each of the UV pulses with an accuracy of + or - of 15%; the uncertainty in the threshold determinations is typically + or - 30%.

  13. A compact efficient deep ultraviolet laser at 266 nm

    NASA Astrophysics Data System (ADS)

    Zhai, S. Y.; Wang, X. L.; Wei, Y.; Chen, W. D.; Zhuang, F. J.; Xu, S.; Li, B. X.; Fu, J. J.; Chen, Z. Q.; Wang, H. W.; Huang, C. H.; Zhang, G.

    2013-04-01

    We present a highly efficient and cost-effective watt-level deep-ultraviolet laser operating at 266 nm. Type-I phase-matching LBO crystals and type-I phase-matching BBO crystals were used for frequency doubling and fourth-harmonic generation, respectively. The highest 1.82 W average power of the 266 nm laser was obtained from nonlinear frequency conversion at a repetition rate of 30 kHz and a pump power of 18.8 W. The conversion efficiency from the diode to the deep-ultraviolet laser scales up to 10.7%. This is, to our knowledge, the highest efficiency ever reported generated from a laser diode single-end-pumped acousto-optic Q-switched system.

  14. Single, composite, and ceramic Nd:YAG 946-nm lasers

    NASA Astrophysics Data System (ADS)

    Lan, Rui-Jun; Yang, Guang; Zheng-Ping, Wang

    2015-06-01

    Single, composite crystal and ceramic continuous wave (CW) 946-nm Nd:YAG lasers are demonstrated, respectively. The ceramic laser behaves better than the crystal laser. With 5-mm long ceramic, a CW output power of 1.46 W is generated with an optical conversion efficiency of 13.9%, while the slope efficiency is 17.9%. The optimal ceramic length for a 946-nm laser is also calculated. Project supported by the National Natural Science Foundation of China (Grant No. 61405171), the Natural Science Foundation of Shandong Province, China (Grant No. ZR2012FQ014), and the Science and Technology Program of the Shandong Higher Education Institutions of China (Grant No. J13LJ05).

  15. Optical responses of a metal with sub-nm gaps.

    PubMed

    Park, Sang Jun; Kim, Tae Yun; Park, Cheol-Hwan; Kim, Dai-Sik

    2016-01-01

    If the size of a metallic structure is reduced to be comparable to or even smaller than the typical quantum-mechanical lengths such as the Fermi wavelength or Thomas-Fermi wavelength, the electronic structure and optical responses are modulated by quantum effects. Here, we calculate the optical responses of a metal with sub-nm gaps using the eigenstates obtained from an effective-mass quantum theory. According to our simulation, the dielectric responses can be significantly modified by tuning the inter-gap distances. Remarkably, sub-nm gaps occupying a 0.3% volumetric fraction can elongate the penetration depth by an order of magnitude in the terahertz regime. We find that the detailed dependences of electron-photon interaction matrix elements on the involved electronic wavefunctions play an important role in the optical responses. The results draw our attention to these recently fabricated systems. PMID:26964884

  16. An evaluation of 685 nm fluorescence imagery of coastal waters

    NASA Technical Reports Server (NTRS)

    Kim, H. H.; Van Der Piepen, H.; Amann, V.; Doerffer, R.

    1985-01-01

    To evaluate the possible application of sunlight-illuminated fluorescence at 685 nm for remote sensing of phytoplankton concentrations, an ocean-color scanner is flown on an aircraft. The results of an analysis of the scanner data, obtained from a series of test flights conducted along the Elbe River and its estuary in the North Sea, show that 685 nm fluorescence is a promising remote-sensing method. The observation of a strong correlation between the fluorescence yields and the chlorophyll concentrations determined by the absorption method which uses the reflectance ratio of blue/green channels, is discussed. The two methods are compared and it is shown that the fluorescence method has an edge over the other due to the data-processing algorithm and its applicability for surveying bio-resources in all types of water. Photographs of the chlorophyll patterns are presented.

  17. Performance of Thin Borosilicate Glass Sheets at 351-nm

    SciTech Connect

    Whitman, P K; Hahn, D; Soules, T; Norton, M; Dixit, S; Donohue, G; Folta, J; Hollingsworth, W; Mainschein-Cline, M

    2004-11-11

    Previously, we reported preliminary results for commercial thin borosilicate glass sheets evaluated for use as a frequently-replaced optic to separate the radiation and contamination produced by the inertial confinement fusion experiments in the National Ignition Facility target chamber from the expensive precision laser optics which focus and shape the 351-nm laser beam. The goal is identification of low cost substrates that can deliver acceptable beam energy and focal spots to the target. The two parameters that dominate the transmitted beam quality are the transmitted wave front error and 351-nm absorption. Commercial materials and fabrication processes have now been identified which meet the beam energy and focus requirements for all of the missions planned for the National Ignition Facility. We present the first data for use of such an optic on the National Ignition Facility laser.

  18. Novel single-layer photoresist containing cycloolefins for 193 nm

    NASA Astrophysics Data System (ADS)

    Park, Joo Hyeon; Seo, Dong-Chul; Kim, Ki-Dae; Park, Sun-Yi; Kim, Seong-Ju; Lee, Hosull; Jung, Jae Chang; Bok, Cheol-Kyu; Baik, Ki-Ho

    1998-06-01

    New matrix resins containing maleic anhydride and cycloolefin units for ArF excimer laser resist have been developed. Several series of these matrix resins having good dry-etching durability were prepared by free radical polymerization using AlBN as free radical initiator. All of the resists using the matrix resins revealed good coating uniformity and adhesion to silicon wafer, and were readily soluble in a variety of resist solvents such as MMP, EEP, PGMEA and EL. In preliminary 193 nm testing a resist formulated with the matrix resins sulfonium triflate as photoacid generator afforded positive images with 0.14 micrometers L/S resolution. In this paper, we will discuss the polymerization results and lithographic properties for 193 nm exposure tool.

  19. Optical responses of a metal with sub-nm gaps

    PubMed Central

    Park, Sang Jun; Kim, Tae Yun; Park, Cheol-Hwan; Kim, Dai-Sik

    2016-01-01

    If the size of a metallic structure is reduced to be comparable to or even smaller than the typical quantum-mechanical lengths such as the Fermi wavelength or Thomas-Fermi wavelength, the electronic structure and optical responses are modulated by quantum effects. Here, we calculate the optical responses of a metal with sub-nm gaps using the eigenstates obtained from an effective-mass quantum theory. According to our simulation, the dielectric responses can be significantly modified by tuning the inter-gap distances. Remarkably, sub-nm gaps occupying a 0.3% volumetric fraction can elongate the penetration depth by an order of magnitude in the terahertz regime. We find that the detailed dependences of electron-photon interaction matrix elements on the involved electronic wavefunctions play an important role in the optical responses. The results draw our attention to these recently fabricated systems. PMID:26964884

  20. 551 nm Generation by sum-frequency mixing of intracavity pumped Nd:YAG laser

    NASA Astrophysics Data System (ADS)

    Dong, Y.; Li, S. T.; Zhang, X. H.

    2012-02-01

    We present for the first time a Nd:YAG laser emitting at 1319 nm intracavity pumped by a 946 nm diode-pumped Nd:YAG laser. A 809 nm laser diode is used to pump the first Nd:YAG crystal emitting at 946 nm, and the second Nd:YAG laser emitting at 1319 nm intracavity pumped at 946 nm. Intracavity sumfrequency mixing at 946 and 1319 nm was then realized in a LBO crystal to reach the yellow range. We obtained a continuous-wave output power of 158 mW at 551 nm with a pump laser diode emitting 18.7 W at 809 nm.

  1. 308-nm Excimer laser treatment of palmoplantar psoriasis.

    PubMed

    Goldberg, David J; Chwalek, Jennifer; Hussain, Mussarrat

    2011-04-01

    Psoriasis is a chronic inflammatory condition affecting 1-3% of the population. The incidence of palmoplantar involvement has been estimated to be between 2.8% and 40.9%. Significant psychosocial distress and difficulty performing activities of daily living can result. Treatment is often challenging. Traditional treatments include topical steroids, anthralin, calcipotriene, PUVA, methotrexate, cyclosporine, retinoids and biologics. In this case series, we report our success with the 308-nm excimer laser in the treatment of palmoplantar psoriasis. PMID:21401376

  2. Measurement of Laser Damage Threshold of 355-nm Antireflection Coating

    NASA Astrophysics Data System (ADS)

    Tamura, Shigeharu; Kimura, Saburo; Sato, Yoshiyuki; Otani, Minoru; Yoshida, Hidetsugu; Yoshida, Kunio

    1989-06-01

    The laser damage thresholds of various types of antireflection (AR) coatings for an UV (355-nm) laser system were measured. Among them, the coatings consisting of two low-index materials, SiO2 and MgF2, had the highest average thresholds: 2.1 J/cm2 on fused silica substrates and 2.6 J/cm2 on sapphire substrates. The SiO2/MgF2 coating is hopeful for UV laser component.

  3. The polarization properties of Fe II 614.9 nm

    NASA Technical Reports Server (NTRS)

    Lites, Bruce W.

    1993-01-01

    The anomalous Zeeman splitting of the Fe II line at 614.9 nm results in four unusual properties of the polarization signature of this line in the presence of magnetic fields: the absence of linear polarization, no magnetooptical effect, the independence of intensity at line center from the inclination of the field, and a depolarizing self-absorption. The origin of these properties is illustrated in terms of the transfer of line radiation in an idealized solar atmosphere.

  4. Hard x-ray Zernike microscopy reaches 30 nm resolution.

    SciTech Connect

    Chen, Y.; Chen, T.; Yi, J.; Chu, Y.; Lee, W.-K.; Wang, C.; Kempson, I.; Hwu, Y.; Gajdosik, V.; Margaritondo, G.

    2011-03-30

    Since its invention in 1930, Zernike phase contrast has been a pillar in optical microscopy and more recently in x-ray microscopy, in particular for low-absorption-contrast biological specimens. We experimentally demonstrate that hard-x-ray Zernike microscopy now reaches a lateral resolution below 30?nm while strongly enhancing the contrast, thus opening many new research opportunities in biomedicine and materials science.

  5. Hard x-ray Zernike Microscopy Reaches 30 nm Resolution

    SciTech Connect

    Chen, Y.T.; Chu, Y.; Chen, T-Y.; Yi, J.; Lee, W-K.; Wang, C-L.; Kempson, I. M.; Hwu, Y.; Gajdosik, V.; Margaritondo, G.

    2011-03-30

    Since its invention in 1930, Zernike phase contrast has been a pillar in optical microscopy and more recently in x-ray microscopy, in particular for low-absorption-contrast biological specimens. We experimentally demonstrate that hard-x-ray Zernike microscopy now reaches a lateral resolution below 30 nm while strongly enhancing the contrast, thus opening many new research opportunities in biomedicine and materials science.

  6. 32 nm logic patterning options with immersion lithography

    NASA Astrophysics Data System (ADS)

    Lai, K.; Burns, S.; Halle, S.; Zhuang, L.; Colburn, M.; Allen, S.; Babcock, C.; Baum, Z.; Burkhardt, M.; Dai, V.; Dunn, D.; Geiss, E.; Haffner, H.; Han, G.; Lawson, P.; Mansfield, S.; Meiring, J.; Morgenfeld, B.; Tabery, C.; Zou, Y.; Sarma, C.; Tsou, L.; Yan, W.; Zhuang, H.; Gil, D.; Medeiros, D.

    2008-03-01

    The semiconductor industry faces a lithographic scaling limit as the industry completes the transition to 1.35 NA immersion lithography. Both high-index immersion lithography and EUV lithography are facing technical challenges and commercial timing issues. Consequently, the industry has focused on enabling double patterning technology (DPT) as a means to circumvent the limitations of Rayleigh scaling. Here, the IBM development alliance demonstrate a series of double patterning solutions that enable scaling of logic constructs by decoupling the pattern spatially through mask design or temporally through innovative processes. These techniques have been successfully employed for early 32nm node development using 45nm generation tooling. Four different double patterning techniques were implemented. The first process illustrates local RET optimization through the use of a split reticle design. In this approach, a layout is decomposed into a series of regions with similar imaging properties and the illumination conditions for each are independently optimized. These regions are then printed separately into the same resist film in a multiple exposure process. The result is a singly developed pattern that could not be printed with a single illumination-mask combination. The second approach addresses 2D imaging with particular focus on both line-end dimension and linewidth control [1]. A double exposure-double etch (DE2) approach is used in conjunction with a pitch-filling sacrificial feature strategy. The third double exposure process, optimized for via patterns also utilizes DE2. In this method, a design is split between two separate masks such that the minimum pitch between any two vias is larger than the minimum metal pitch. This allows for final structures with vias at pitches beyond the capability of a single exposure. In the fourth method,, dark field double dipole lithography (DDL) has been successfully applied to BEOL metal structures and has been shown to be

  7. Step and flash imprint lithography for sub-100-nm patterning

    NASA Astrophysics Data System (ADS)

    Colburn, Matthew; Grot, Annette; Amistoso, Marie N.; Choi, Byung J.; Bailey, Todd C.; Ekerdt, John G.; Sreenivasan, S. V.; Hollenhorst, James; Willson, C. Grant

    2000-07-01

    Step and Flash Imprint Lithography (SFIL) is an alternative to photolithography that efficiently generates high aspect-ratio, sub-micron patterns in resist materials. Other imprint lithography techniques based on physical deformation of a polymer to generate surface relief structures have produced features in PMMA as small as 10 nm, but it is very difficult to imprint large depressed features or to imprint a thick films of resist with high aspect-ratio features by these techniques. SFIL overcomes these difficulties by exploiting the selectivity and anisotropy of reactive ion etch (RIE). First, a thick organic 'transfer' layer (0.3 micrometer to 1.1 micrometer) is spin coated to planarize the wafer surface. A low viscosity, liquid organosilicon photopolymer precursor is then applied to the substrate and a quartz template applied at 2 psi. Once the master is in contact with the organosilicon solution, a crosslinking photopolymerization is initiated via backside illumination with broadband UV light. When the layer is cured the template is removed. This process relies on being able to imprint the photopolymer while leaving the minimal residual material in the depressed areas. Any excess material is etched away using a CHF3/He/O2 RIE. The exposed transfer layer is then etched with O2 RIE. The silicon incorporated in the photopolymer allows amplification of the low aspect ratio relief structure in the silylated resist into a high aspect ratio feature in the transfer layer. The aspect ratio is limited only by the mechanical stability of the transfer layer material and the O2 RIE selectivity and anisotropy. This method has produced 60 nm features with 6:1 aspect ratios. This lithography process was also used to fabricate alternating arrays of 100 nm Ti lines on a 200 nm pitch that function as efficient micropolarizers. Several types of optical devices including gratings, polarizers, and sub-wavelength structures can be easily patterned by SFIL.

  8. 193 nm photodissociation of larger multiply-charged biomolecules

    NASA Astrophysics Data System (ADS)

    Guan, Ziqiang; Kelleher, Neil L.; O'Connor, Peter B.; Aaserud, David J.; Little, Daniel P.; McLafferty, Fred W.

    1996-12-01

    In contrast to most ion dissociation methods, 193 nm ultraviolet photodissociation of electrosprayed melittin (2.8 kDa) and ubiquitin (8.6 kDa) molecular ions yields new c and z ions (backbone amine bond dissociation) that provide additional sequence information. Dissociation by collisions or infrared photons produce b and y ions; for cleavages between the same amino acids the c ion represents the addition of NH2 to the b ion, and z the loss of NH2 from the y ion, so that these ions can be differentiated by this ± 16.02 Da difference. However, 193 nm photodissociation of 12-29 kDa ions as yet does not give collectable product ions, and that of the very stable y182+ ion from ubiquitin only effects a side chain loss. 193 nm irradiation of negative ions of all-T 30-mer DNA appears to eject electrons; apparently this is the first observation of electron photodetachment from multiply-charged negative ions.

  9. Advances in 193 nm excimer lasers for mass spectrometry applications

    NASA Astrophysics Data System (ADS)

    Delmdahl, Ralph; Esser, Hans-Gerd; Bonati, Guido

    2016-03-01

    Ongoing progress in mass analysis applications such as laser ablation inductively coupled mass spectrometry of solid samples and ultraviolet photoionization mediated sequencing of peptides and proteins is to a large extent driven by ultrashort wavelength excimer lasers at 193 nm. This paper will introduce the latest improvements achieved in the development of compact high repetition rate excimer lasers and elaborate on the impact on mass spectrometry instrumentation. Various performance and lifetime measurements obtained in a long-term endurance test over the course of 18 months will be shown and discussed in view of the laser source requirements of different mass spectrometry tasks. These sampling type applications are served by excimer lasers delivering pulsed 193 nm output of several mJ as well as fast repetition rates which are already approaching one Kilohertz. In order to open up the pathway from the laboratory to broader market industrial use, sufficient component lifetimes and long-term stable performance behavior have to be ensured. The obtained long-term results which will be presented are based on diverse 193 nm excimer laser tube improvements aiming at e.g. optimizing the gas flow dynamics and have extended the operational life the laser tube for the first time over several billion pulses even under high duty-cycle conditions.

  10. Photoelectron Emission Studies in CsBr at 257 nm

    SciTech Connect

    Maldonado, Juan R.; Liu, Zhi; Sun, Yun; Pianetta, Piero A.; Pease, Fabian W.; /Stanford U., Elect. Eng. Dept. /SLAC, SSRL

    2006-09-28

    CsBr/Cr photocathodes were found [1,2] to meet the requirements of a multi-electron beam lithography system operating with a light energy of 4.8 eV (257nm). The fact that photoemission was observed with a light energy below the reported 7.3 eV band gap for CsBr was not understood. This paper presents experimental results on the presence of intra-band gap absorption sites (IBAS) in CsBr thin film photo electron emitters, and presents a model based on IBAS to explain the observed photoelectron emission behavior at energies below band gap. A fluorescence band centered at 330 nm with a FWHM of about 0.34 eV was observed in CsBr/Cr samples under 257 nm laser illumination which can be attributed to IBAS and agrees well with previously obtained synchrotron photoelectron spectra[1] from the valence band of CsBr films.

  11. Ion transport in sub-5-nm graphene nanopores

    NASA Astrophysics Data System (ADS)

    Suk, Myung E.; Aluru, N. R.

    2014-02-01

    Graphene nanopore is a promising device for single molecule sensing, including DNA bases, as its single atom thickness provides high spatial resolution. To attain high sensitivity, the size of the molecule should be comparable to the pore diameter. However, when the pore diameter approaches the size of the molecule, ion properties and dynamics may deviate from the bulk values and continuum analysis may not be accurate. In this paper, we investigate the static and dynamic properties of ions with and without an external voltage drop in sub-5-nm graphene nanopores using molecular dynamics simulations. Ion concentration in graphene nanopores sharply drops from the bulk concentration when the pore radius is smaller than 0.9 nm. Ion mobility in the pore is also smaller than bulk ion mobility due to the layered liquid structure in the pore-axial direction. Our results show that a continuum analysis can be appropriate when the pore radius is larger than 0.9 nm if pore conductivity is properly defined. Since many applications of graphene nanopores, such as DNA and protein sensing, involve ion transport, the results presented here will be useful not only in understanding the behavior of ion transport but also in designing bio-molecular sensors.

  12. 1060nm VCSEL development at Furukawa for parallel optical interconnect

    NASA Astrophysics Data System (ADS)

    Funabashi, Masaki; Imai, Suguru; Takaki, Keishi; Kamiya, Shinichi; Shimizu, Hitoshi; Kawakita, Yasumasa; Hiraiwa, Koji; Yoshida, Junji; Suzuki, Toshihito; Ishikawa, Takuya; Tsukiji, Naoki; Kasukawa, Akihiko

    2012-03-01

    This paper reviews research and development of 1060nm VCSELs at Furukawa Electric. We pursue the simultaneous realization of three strong demands for low power consumption, high reliability, and high speed. For this purpose, we have chosen compressively strained InGaAs/GaAs active layers emitting in a 1060 nm wavelength range because of their advantages of lower threshold voltage, smaller defect propagation velocity, and larger material differential gain, compared to those of GaAs/AlGaAs active layers widely used in 850 nm VCSELs. Oxide-confined and double intracavity structures provide low and stable electrical resistance as well as low optical loss. The developed VCSELs exhibited low threshold currents of 0.31 mA at 25 °C and 0.56 mA at 90 °C, together with highly uniform slope efficiency distributions throughout a wafer. We also demonstrated 10 Gbps error free transmission at a very low bias current of 1.4 mA, yielding low power dissipation operation of 0.14 mW/Gbps. Clear eye openings up to 20 Gbps were confirmed at a low bias current of 3mA. A series of endurance tests and accelerated aging tests on nearly 5000 VCSELs have proved Telcordia qualified high reliability and a very low failure rate of 30 FIT/channel at an operating temperature of 40 °C and a bias current of 6mA, with a 90% confidential level.

  13. Composition of 15-80 nm particles in marine air

    NASA Astrophysics Data System (ADS)

    Lawler, M. J.; Whitehead, J.; O'Dowd, C.; Monahan, C.; McFiggans, G.; Smith, J. N.

    2014-01-01

    The chemical composition of 15-80 nm diameter particles was measured at Mace Head, Ireland, during May 2011 using the TDCIMS (Thermal Desorption Chemical Ionization Mass Spectrometer). Measurable levels of chloride, sodium, and sulfate were present in essentially all collected samples of these particles at this coastal Atlantic site. Organic compounds were rarely detectable, but this was likely an instrumental limitation. Concomitant particle hygroscopicity observations usually showed two main modes, one which contained a large sea salt component and another which was likely dominated by sulfate. There were several occasions lasting from hours to about two days during which 10-60 nm particle number increased dramatically in polar oceanic air. During these events, the sulfate mode increased substantially in number. This observation, along with the presence of very small (<10 nm) particles during the events, suggests that the particles were formed by homogeneous nucleation, followed by subsequent growth by sulfuric acid and potentially other vapors. The frequency of the events and similarity of event particles to background particles suggest that these events are important contributors of nanoparticles in this environment.

  14. Ion transport in sub-5-nm graphene nanopores

    SciTech Connect

    Suk, Myung E.; Aluru, N. R.

    2014-02-28

    Graphene nanopore is a promising device for single molecule sensing, including DNA bases, as its single atom thickness provides high spatial resolution. To attain high sensitivity, the size of the molecule should be comparable to the pore diameter. However, when the pore diameter approaches the size of the molecule, ion properties and dynamics may deviate from the bulk values and continuum analysis may not be accurate. In this paper, we investigate the static and dynamic properties of ions with and without an external voltage drop in sub-5-nm graphene nanopores using molecular dynamics simulations. Ion concentration in graphene nanopores sharply drops from the bulk concentration when the pore radius is smaller than 0.9 nm. Ion mobility in the pore is also smaller than bulk ion mobility due to the layered liquid structure in the pore-axial direction. Our results show that a continuum analysis can be appropriate when the pore radius is larger than 0.9 nm if pore conductivity is properly defined. Since many applications of graphene nanopores, such as DNA and protein sensing, involve ion transport, the results presented here will be useful not only in understanding the behavior of ion transport but also in designing bio-molecular sensors.

  15. Brain lesion induced by 1319nm laser radiation

    NASA Astrophysics Data System (ADS)

    Yang, Zaifu; Chen, Hongxia; Wang, Jiarui; Chen, Peng; Ma, Ping; Qian, Huanwen

    2010-11-01

    The laser-tissue interaction has not been well defined at the 1319 nm wavelength for brain exposure. The goal of this research effort was to identify the behavioral and histological changes of brain lesion induced by 1319 nm laser. The experiment was performed on China Kunming mice. Unilateral brain lesions were created with a continuous-wave Nd:YAG laser (1319nm). The brain lesions were identified through behavioral observation and histological haematoxylin and eosin (H&E) staining method. The behavior change was observed for a radiant exposure range of 97~773 J/cm2. The histology of the recovery process was identified for radiant exposure of 580 J/cm2. Subjects were sacrificed 1 hour, 1 week, 2 weeks, 3 months, 7 months and 13 months after laser irradiation. Results showed that after laser exposure, behavioral deficits, including kyphosis, tail entasia, or whole body paralysis could be noted right after the animals recovered from anesthesia while gradually disappeared within several days and never recurred again. Histologically, the laser lesion showed a typical architecture dependent on the interval following laser treatment. The central zone of coagulation necrosis is not apparent right after exposure but becomes obvious within several days. The nerotic tissue though may persist for a long time, will finally be completely resorbed. No carbonization granules formed under our exposure condition.

  16. Adamantane based molecular glass resist for 193 nm lithography

    NASA Astrophysics Data System (ADS)

    Tanaka, Shinji; Ober, Christopher K.

    2006-03-01

    As the feature dimensions decreases there are several issues must be addressed to implement the corresponding technology in high volume production. Line width roughness (LWR) and line edge roughness (LER) are the most important technological issue arises as the feature dimension decreases. In order to improve both of LWR and LER, we have developed novel low molecular weight glass resists as high performance resist materials. These molecular glass resists are adamantane derivatives and are highly transparent at 193 nm. We have prepared series of new molecular glass resists based on adamantane core carrying acetal and ester protecting groups. Particularly, adamantane core derivatives of tripod structure were investigated in detail. Several compositions of them showed glass transition temperatures (Tg) above 120 °C. Lithographic evaluation confirmed their high sensitivity at 254 nm and e-beam exposure. It also resolved feature size as small as 200 nm line/space when it evaluated using e-beam lithography. These new molecular glass resists also have high plasma-etch resistance.

  17. 1064 nm SERS of NIR active hollow gold nanotags.

    PubMed

    Kearns, H; Shand, N C; Smith, W E; Faulds, K; Graham, D

    2015-01-21

    Surface enhanced Raman scattering (SERS) tags are in situ probes that can provide sensitive and selective probes for optical analysis in biological materials. Engineering tags for use in the near infrared (NIR) region is of particular interest since there is an uncongested spectral window for optical analysis due to the low background absorption and scattering from many molecules. An improved synthesis has resulted in the formation of hollow gold nanoshells (HGNs) with a localised surface plasmon resonance (LSPR) between 800 and 900 nm which provide effective SERS when excited at 1064 nm. Seven Raman reporters containing aromatic amine or thiol attachment groups were investigated. All were effective but 1,2-bis(4-pyridyl)ethylene (BPE) and 4,4-azopyridine (AZPY) provided the largest enhancement. At approximately monolayer coverage, these two reporters appear to pack with the main axis of the molecule perpendicular or nearly perpendicular to the surface giving strong SERS and thus providing effective 1064 nm gold SERS nanotags. PMID:25475892

  18. Hydrogen evolution reaction catalyst

    DOEpatents

    Subbaraman, Ram; Stamenkovic, Vojislav; Markovic, Nenad; Tripkovic, Dusan

    2016-02-09

    Systems and methods for a hydrogen evolution reaction catalyst are provided. Electrode material includes a plurality of clusters. The electrode exhibits bifunctionality with respect to the hydrogen evolution reaction. The electrode with clusters exhibits improved performance with respect to the intrinsic material of the electrode absent the clusters.

  19. Chemical Reaction Problem Solving.

    ERIC Educational Resources Information Center

    Veal, William

    1999-01-01

    Discusses the role of chemical-equation problem solving in helping students predict reaction products. Methods for helping students learn this process must be taught to students and future teachers by using pedagogical skills within the content of chemistry. Emphasizes that solving chemical reactions should involve creative cognition where…

  20. Applications of Reaction Rate

    ERIC Educational Resources Information Center

    Cunningham, Kevin

    2007-01-01

    This article presents an assignment in which students are to research and report on a chemical reaction whose increased or decreased rate is of practical importance. Specifically, students are asked to represent the reaction they have chosen with an acceptable chemical equation, identify a factor that influences its rate and explain how and why it…

  1. REUSABLE REACTION VESSEL

    DOEpatents

    Soine, T.S.

    1963-02-26

    This patent shows a reusable reaction vessel for such high temperature reactions as the reduction of actinide metal chlorides by calcium metal. The vessel consists of an outer metal shell, an inner container of refractory material such as sintered magnesia, and between these, a bed of loose refractory material impregnated with thermally conductive inorganic salts. (AEC)

  2. Nuclear Reaction Data Centers

    SciTech Connect

    McLane, V.; Nordborg, C.; Lemmel, H.D.; Manokhin, V.N.

    1988-01-01

    The cooperating Nuclear Reaction Data Centers are involved in the compilation and exchange of nuclear reaction data for incident neutrons, charged particles and photons. Individual centers may also have services in other areas, e.g., evaluated data, nuclear structure and decay data, reactor physics, nuclear safety; some of this information may also be exchanged between interested centers. 20 refs., 1 tab.

  3. Degradations and Rearrangement Reactions

    NASA Astrophysics Data System (ADS)

    Zhang, Jianbo

    This section deals with recent reports concerning degradation and rearrangement reactions of free sugars as well as some glycosides. The transformations are classified in chemical and enzymatic ways. In addition, the Maillard reaction will be discussed as an example of degradation and rearrangement transformation and its application in current research in the fields of chemistry and biology.

  4. Oscillating Reactions: Two Analogies

    ERIC Educational Resources Information Center

    Petruševski, Vladimir M.; Stojanovska, Marina I.; Šoptrajanov, Bojan T.

    2007-01-01

    Oscillating chemical reactions are truly spectacular phenomena, and demonstrations are always appreciated by the class. However, explaining such reactions to high school or first-year university students is problematic, because it may seem that no acceptable explanation is possible unless the students have profound knowledge of both physical…

  5. Clock Reaction: Outreach Attraction

    ERIC Educational Resources Information Center

    Carpenter, Yuen-ying; Phillips, Heather A.; Jakubinek, Michael B.

    2010-01-01

    Chemistry students are often introduced to the concept of reaction rates through demonstrations or laboratory activities involving the well-known iodine clock reaction. For example, a laboratory experiment involving thiosulfate as an iodine scavenger is part of the first-year general chemistry laboratory curriculum at Dalhousie University. With…

  6. Chemical burn or reaction

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/000059.htm Chemical burn or reaction To use the sharing features on this page, please enable JavaScript. Chemicals that touch skin can lead to a reaction on the skin, throughout the body, or both. ...

  7. Oxygenation of human blood using photocatalytic reaction.

    PubMed

    Subrahmanyam, Aryasomayajula; Ramesh, Thangaraj P; Ramakrishnan, Nagarajan

    2007-01-01

    This report, as a proof of concept, presents the results of oxygenation of human blood using photocatalytic reaction (at lambda = 352 nm) involving the semiconductor thin film junction: tin doped indium oxide (ITO)/nano titanium oxide (TiO2 in anatase structure). These thin films were prepared at room temperature (300 K) on quartz, using reactive DC Magnetron sputtering techniques from pure metallic targets. The results indicate that when 10.0 mL of blood was exposed to ITO/nano TiO2 (14.32 cm surface area) at a wavelength of 352 nm for 120 minutes, the absolute increase in the whole blood oxygen content was 10.13 mL of oxygen per 100.0 mL of blood. This experiment, to our knowledge, is the first of its kind on human blood. PMID:17667227

  8. First Operation of a Free-Electron Laser Generating GW Power Radiation at 32-Nm Wavelength

    SciTech Connect

    Ayvazian, V.; Baboi, N.; Bahr, J.; Balandin, V.; Beutner, B.; Brandt, A.; Bohnet, I.; Bolzmann, A.; Brinkmann, R.; Brovko, O.I.; Carneiro, J.P.; Casalbuoni, S.; Castellano, M.; Castro, P.; Catani, L.; Chiadroni, E.; Choroba, S.; Cianchi, A.; Delsim-Hashemi, H.; Di Pirro, G.; Dohlus, M.; /Saclay /Wurzburg U. /BESSY, Berlin /CANDLE, Yerevan /Darmstadt, Tech. Hochsch. /DESY /DESY, Zeuthen /Fermilab /Hamburg U. /INFM, Padua /Frascati /INFN, Milan /INFN, Rome2 /Sofiya, Inst. Nucl. Res. /Dubna, JINR /Orsay, LAL /Max Born Inst., Berlin /SLAC

    2006-09-15

    Many scientific disciplines ranging from physics, chemistry and biology to material sciences, geophysics and medical diagnostics need a powerful X-ray source with pulse lengths in the femtosecond range. This would allow, for example, time-resolved observation of chemical reactions with atomic resolution. Such radiation of extreme intensity, and tunable over a wide range of wavelengths, can be accomplished using high-gain free-electron lasers (FEL). Here we present results of the first successful operation of an FEL at a wavelength of 32 nm, with ultra-short pulses (25 fs FWHM), a peak power at the Gigawatt level, and a high degree of transverse and longitudinal coherence. The experimental data are in full agreement with theory. This is the shortest wavelength achieved with an FEL to date and an important milestone towards a user facility designed for wavelengths down to 6 nm. With a peak brilliance exceeding the state-of-the-art of synchrotron radiation sources by seven orders of magnitude, this device opens a new field of experiments, and it paves the way towards sources with even shorter wavelengths, such as the Linac Coherent Light Source at Stanford, USA, and the European X-ray Free Electron Laser Facility in Hamburg, Germany.

  9. Latitudinal variation of 732.0 nm dayglow emission under geomagnetic storm conditions

    NASA Astrophysics Data System (ADS)

    Singh, Vir; Dharwan, Maneesha

    2016-07-01

    A comprehensive model is developed to study 732.0 nm dayglow emission. The Solar2000 EUV (extreme ultraviolet) flux model, neutral atmosphere model (NRLMSISE-00), latest transition probabilities and updated reaction rate coefficients are incorporated in the present model. The modeled volume emission rates (VER) are compared with the measurements as provided by Atmosphere Explorer-C satellite, Dynamics Explorer-2 spacecraft and WINDII measurements. The model is found in very good agreement with the measurements. This model is used to study the effects of geomagnetic storm on the 732.0 nm dayglow emission at various latitudes in northern hemisphere. It is found that the VER decreases as the latitude increases. The decrease in VER from low to mid latitudes is due to the decrease in atomic oxygen number density with latitude. The zenith intensity at the maximum geomagnetic activity is about 15% higher than the zenith intensity before the start of the geomagnetic storm in equatorial region. However, no appreciable change in the zenith intensity is found at higher latitudes (above 50° N). Further a negative correlation is found between the volume emission rate and DST index at all latitudes.

  10. Below 70-nm contact hole pattern with RELACS process on ArF resist

    NASA Astrophysics Data System (ADS)

    Terai, Mamoru; Toyoshima, Toshiyuki; Ishibashi, Takeo; Tarutani, Shinji; Takahashi, Kiyohisa; Takano, Yusuke; Tanaka, Hatsuyuki

    2003-06-01

    A chemical shrink technology, RELACS (Resolution Enhancement Lithography Assisted by Chemical Shrink), utilizes the cross linking reaction catalyzed by the acid component existing in a predefined resist pattern. This "RELACS" process is a hole shrinking procedure that includes simple coating, baking, and rinsing applied after conventional photolithography. Our target is realize of sub-70nm hole pattern formation by using new RELACS for ArF resist. At present, RELACS process is introduced to mass production of KrF lithography by using AZ R200 (Product name of Clariant) mainly. Then first of all we reported process performance of conventional RELACS material, AZ R200 with ArF resist. However AZ R200 does not show satisfactory shrinkage on ArF resist. Thereupon, we started on the development of new RELACS corresponding to ArF resist. As the result, we developed new RELACS material including Cross Linking Accelerator (CLA). It was found that CLA is able to improve reactivity of RELACS with ArF-resist. By using this new RELACS, It is Realized sub-70nm hole pattern formation with ArF-Ex lithography and It is able to Control of hole size by mixing bake (MB) temperature and additive ratio of CLA. Moreover this process was realized that thickness of shrunk hole is increased.

  11. Lack of photoprotection against UVB-induced erythema by immediate pigmentation induced by 382 nm radiation

    SciTech Connect

    Black, G.; Matzinger, E.; Gange, R.W.

    1985-11-01

    Immediate pigment darkening (IPD) was induced on the backs of 11 human volunteers of skin types III and IV by exposing the skin to UVA radiation (382 nm). The minimum erythema dose (MED) of UVB radiation was also determined by exposing sites to graduated doses of 304 nm radiation. The order of exposure of distinct anatomic areas was as follow: UVB followed by IPD induction; IPD induction followed by UVB; IPD induction followed 3 h later by UVB; and UVB only. Erythema responses induced by UVB were graded by inspection 24 h later and the MEDs in the 4 areas were compared. The induction of IPD before UVB exposure caused no significant change in the MED compared to sites receiving UVB only, or receiving UVA radiation after UVB, confirming that the IPD reaction does not protect against UVB-induced erythema. There was also no evidence of photorecovery, i.e., an increase in the MED of UVB resulting from exposure to longer wavelength, UV or visible radiation following UVB exposure.

  12. First operation of a free-electron laser generating GW power radiation at 32 nm wavelength

    NASA Astrophysics Data System (ADS)

    Ayvazyan, V.; Baboi, N.; Bähr, J.; Balandin, V.; Beutner, B.; Brandt, A.; Bohnet, I.; Bolzmann, A.; Brinkmann, R.; Brovko, O. I.; Carneiro, J. P.; Casalbuoni, S.; Castellano, M.; Castro, P.; Catani, L.; Chiadroni, E.; Choroba, S.; Cianchi, A.; Delsim-Hashemi, H.; di Pirro, G.; Dohlus, M.; Düsterer, S.; Edwards, H. T.; Faatz, B.; Fateev, A. A.; Feldhaus, J.; Flöttmann, K.; Frisch, J.; Fröhlich, L.; Garvey, T.; Gensch, U.; Golubeva, N.; Grabosch, H.-J.; Grigoryan, B.; Grimm, O.; Hahn, U.; Han, J. H.; Hartrott, M. V.; Honkavaara, K.; Hüning, M.; Ischebeck, R.; Jaeschke, E.; Jablonka, M.; Kammering, R.; Katalev, V.; Keitel, B.; Khodyachykh, S.; Kim, Y.; Kocharyan, V.; Körfer, M.; Kollewe, M.; Kostin, D.; Krämer, D.; Krassilnikov, M.; Kube, G.; Lilje, L.; Limberg, T.; Lipka, D.; Löhl, F.; Luong, M.; Magne, C.; Menzel, J.; Michelato, P.; Miltchev, V.; Minty, M.; Möller, W. D.; Monaco, L.; Müller, W.; Nagl, M.; Napoly, O.; Nicolosi, P.; Nölle, D.; Nuñez, T.; Oppelt, A.; Pagani, C.; Paparella, R.; Petersen, B.; Petrosyan, B.; Pflüger, J.; Piot, P.; Plönjes, E.; Poletto, L.; Proch, D.; Pugachov, D.; Rehlich, K.; Richter, D.; Riemann, S.; Ross, M.; Rossbach, J.; Sachwitz, M.; Saldin, E. L.; Sandner, W.; Schlarb, H.; Schmidt, B.; Schmitz, M.; Schmüser, P.; Schneider, J. R.; Schneidmiller, E. A.; Schreiber, H.-J.; Schreiber, S.; Shabunov, A. V.; Sertore, D.; Setzer, S.; Simrock, S.; Sombrowski, E.; Staykov, L.; Steffen, B.; Stephan, F.; Stulle, F.; Sytchev, K. P.; Thom, H.; Tiedtke, K.; Tischer, M.; Treusch, R.; Trines, D.; Tsakov, I.; Vardanyan, A.; Wanzenberg, R.; Weiland, T.; Weise, H.; Wendt, M.; Will, I.; Winter, A.; Wittenburg, K.; Yurkov, M. V.; Zagorodnov, I.; Zambolin, P.; Zapfe, K.

    2006-02-01

    Many scientific disciplines ranging from physics, chemistry and biology to material sciences, geophysics and medical diagnostics need a powerful X-ray source with pulse lengths in the femtosecond range [1-4]. This would allow, for example, time-resolved observation of chemical reactions with atomic resolution. Such radiation of extreme intensity, and tunable over a wide range of wavelengths, can be accomplished using high-gain free-electron lasers (FEL) [5-10]. Here we present results of the first successful operation of an FEL at a wavelength of 32 nm, with ultra-short pulses (25 fs FWHM), a peak power at the Gigawatt level, and a high degree of transverse and longitudinal coherence. The experimental data are in full agreement with theory. This is the shortest wavelength achieved with an FEL to date and an important milestone towards a user facility designed for wavelengths down to 6 nm. With a peak brilliance exceeding the state-of-the-art of synchrotron radiation sources [4] by seven orders of magnitude, this device opens a new field of experiments, and it paves the way towards sources with even shorter wavelengths, such as the Linac Coherent Light Source [3] at Stanford, USA, and the European X-ray Free Electron Laser Facility [4] in Hamburg, Germany.

  13. 1.7 nm platinum nanoparticles: synthesis with glucose starch, characterization and catalysis.

    PubMed

    Engelbrekt, Christian; Sørensen, Karsten Holm; Lübcke, Teis; Zhang, Jingdong; Li, Qingfeng; Pan, Chao; Bjerrum, Niels J; Ulstrup, Jens

    2010-09-10

    Monodisperse platinum nanoparticles (PtNPs) were synthesized by a green recipe. Glucose serves as a reducing agent and starch as a stabilization agent to protect the freshly formed PtNP cores in buffered aqueous solutions. Among the ten buffers studied, 2-(N-morpholino)ethanesulfonic acid (MES), ammonium acetate and phosphate are the best media for PtNP size control and fast chemical preparation. The uniform sizes of the metal cores were determined by transmission electron microscopy (TEM) and found to be 1.8 ± 0.5, 1.7 ± 0.2 and 1.6 ± 0.5 nm in phosphate, MES and ammonium acetate buffer, respectively. The estimated total diameter of the core with a starch coating layer is 5.8-6.0 nm, based on thermogravimetric analysis (TGA). The synthesis reaction is simple, environmentally friendly, highly reproducible, and easy to scale up. The PtNPs were characterized electrochemically and show high catalytic activity for reduction of dioxygen and hydrogen peroxide as well as for oxidation of dihydrogen. The PtNPs can be transferred to carbon support materials with little demand for high specific surface area of carbon. This enables utilization of graphitized carbon blacks to prepare well-dispersed Pt/C catalysts, which exhibit significantly improved durability in the accelerated aging test under fuel cell mimicking conditions. PMID:20715275

  14. Lipases in lipophilization reactions.

    PubMed

    Villeneuve, Pierre

    2007-01-01

    Lipases are used in various sectors, as pharmaceutical, food or detergency industry. Their advantage versus classical chemical catalysts is that they exhibit a better selectivity and operate in milder reaction conditions. Theses enzymes can also be used in lipophilization reactions corresponding to the grafting of a lipophilic moiety to a hydrophilic one such as sugar, amino acids and proteins, or phenolic compounds. The major difficulty to overcome in such enzyme-catalyzed reaction resides in the fact that the two involved substrates greatly differ in term of polarity and solvent affinity. Therefore, several key parameters are to be considered in order to achieve the reaction in satisfactory kinetics and yields. The present review discusses the nature of such parameters (eg solvent nature, water activity, chemical modification of substrates) and illustrates their effect with examples of lipase-catalyzed lipophilization reactions of various sugar, amino acids or phenolic derivatives. PMID:17681737

  15. Inline detection of Chrome degradation on binary 193nm photomasks

    NASA Astrophysics Data System (ADS)

    Dufaye, Félix; Sippel, Astrid; Wylie, Mark; García-Berríos, Edgardo; Crawford, Charles; Hess, Carl; Sartelli, Luca; Pogliani, Carlo; Miyashita, Hiroyuki; Gough, Stuart; Sundermann, Frank; Brochard, Christophe

    2013-09-01

    193nm binary photomasks are still used in the semiconductor industry for the lithography of some critical layers for the nodes 90nm and 65nm, with high volumes and over long periods. However, these 193nm binary photomasks can be impacted by a phenomenon of chrome oxidation leading to critical dimensions uniformity (CDU) degradation with a pronounced radial signature. If not detected early enough, this CDU degradation may cause defectivity issues and lower yield on wafers. Fortunately, a standard cleaning and repellicle service at the mask shop has been demonstrated as efficient to remove the grown materials and get the photomask CD back on target.Some detection methods have been already described in literature, such as wafer CD intrafield monitoring (ACLV), giving reliable results but also consuming additional SEM time with less precision than direct photomask measurement. In this paper, we propose another approach, by monitoring the CDU directly on the photomask, concurrently with defect inspection for regular requalification to production for wafer fabs. For this study, we focused on a Metal layer in a 90nm technology node. Wafers have been exposed with production conditions and then measured by SEM-CD. Afterwards, this photomask has been measured with a SEM-CD in mask shop and also inspected on a KLA-Tencor X5.2 inspection system, with pixels 125 and 90nm, to evaluate the Intensity based Critical Dimension Uniformity (iCDU) option. iCDU was firstly developed to provide feed-forward CDU maps for scanner intrafield corrections, from arrayed dense structures on memory photomasks. Due to layout complexity and differing feature types, CDU monitoring on logic photomasks used to pose unique challenges.The selection of suitable feature types for CDU monitoring on logic photomasks is no longer an issue, since the transmitted intensity map gives all the needed information, as shown in this paper. In this study, the photomask was heavily degraded after more than 18,000 300

  16. KEY COMPARISON: Final report on CCPR K1-a: Spectral irradiance from 250 nm to 2500 nm

    NASA Astrophysics Data System (ADS)

    Woolliams, Emma R.; Fox, Nigel P.; Cox, Maurice G.; Harris, Peter M.; Harrison, Neil J.

    2006-01-01

    The CCPR K1-a key comparison of spectral irradiance (from 250 nm to 2500 nm) was carried out to meet the requirements of the Mutual Recognition Arrangement by 13 participating national metrology institutes (NMIs). Because of the fragile nature of the tungsten halogen lamps used as comparison artefacts, the comparison was arranged as a star comparison with three lamps per participant. NPL (United Kingdom) piloted the comparison and, by measuring all lamps, provided a link between participants' measurements. The other participants were BNM-INM (France), CENAM (Mexico), CSIRO (Australia), HUT (Finland), IFA-CSIC (Spain), MSL-IRL (New Zealand), NIM (China), NIST (United States of America), NMIJ (Japan), NRC (Canada), PTB (Germany) and VNIIOFI (Russian Federation). Before the analysis was completed and the results known, the pilot discussed with each participant which lamp measurements should be included as representative of their comparison. As a consequence of this check, at least one measurement was excluded from one third of the lamps because of changes due to transportations. The comparison thus highlighted the difficulty regarding the availability of suitable transfer standards for the dissemination of spectral irradiance. The use of multiple lamps and multiple measurements ensured sufficient redundancy that all participants were adequately represented. In addition, during this pre-draft A phase all participants had the opportunity to review the uncertainty budgets and methods of all other participants. This new process helped to ensure that all submitted results and their associated uncertainties were evaluated in a consistent manner. The comparison was analysed using a model-based method which regarded each lamp as having a stable spectral irradiance and the measurements made by an NMI as systematically influenced by a factor that applies to all that NMI's measurements. The aim of the analysis was to estimate the systematic factor for each NMI. Across the

  17. Pupillary responses of chromatic stimulus in the visible spectrum 400 nm of 650 nm, in the stable state

    NASA Astrophysics Data System (ADS)

    Guzman, D. R.; Lopez, A. Z.; Gomez, E. S.

    2005-08-01

    an instrumental methodology was implemented to analyze the pupillary responses in the dilation and contraction process elicited by chromatic stimulus. Chromatic stimuli were employed in the visible spectrum from 400 nm to 650 nm. Three different stimulation software was developed and used in order to obtain a contrasted pupillary response PG0, PG12 and PG20. This test was applied to 39 subjects (29 male, 9 female and I child, 22-52 years and 6 years), 10 of them were stimulated with PG0, 21 were stimulated with PG12 and 16 with PG20. 6 subjects participate at least in 2 tests. Ishihara plates were exhibited to the Subjects before the stimulation, 37 of the present a normal vision color, I present deuteranopy.

  18. A nanosecond regenerative Ti:Sapphire amplifier for the simultaneous generation of 940 nm and of 320 nm pulses

    NASA Astrophysics Data System (ADS)

    Talluto, Vincenzo; Blochowicz, Thomas; Walther, Thomas

    2016-05-01

    Narrowband cw radiation at 940 and 960 nm is used to seed a Nd:YAG-pumped regenerative Ti:Sapphire amplifier. A Pockels cell traps a slice of the seed radiation inside the amplifier cavity, generating two synchronized pulses and releasing them after amplification. The total pulse energy is as high as 9 mJ at a pulse duration of 6.5 ns and a Fourier-transform-limited bandwidth. The timing jitter between the two pulses at the two wavelengths is less than ±300 ps. The relative pulse energy can be controlled by the relative seed laser power. Up to 1 mJ pulse energy at 320 nm was achieved by third-harmonic generation.

  19. Megahertz FDML laser with up to 143nm sweep range for ultrahigh resolution OCT at 1050nm

    NASA Astrophysics Data System (ADS)

    Kolb, Jan Philip; Klein, Thomas; Eibl, Matthias; Pfeiffer, Tom; Wieser, Wolfgang; Huber, Robert

    2016-03-01

    We present a new design of a Fourier Domain Mode Locked laser (FDML laser), which provides a new record in sweep range at ~1μm center wavelength: At the fundamental sweep rate of 2x417 kHz we reach 143nm bandwidth and 120nm with 4x buffering at 1.67MHz sweep rate. The latter configuration of our system is characterized: The FWHM of the point spread function (PSF) of a mirror is 5.6μm (in tissue). Human in vivo retinal imaging is performed with the MHz laser showing more details in vascular structures. Here we could measure an axial resolution of 6.0μm by determining the FWHM of specular reflex in the image. Additionally, challenges related to such a high sweep bandwidth such as water absorption are investigated.

  20. Flux calibration of medium-resolution spectra from 300 nm to 2500 nm: Model reference spectra and telluric correction

    NASA Astrophysics Data System (ADS)

    Moehler, S.; Modigliani, A.; Freudling, W.; Giammichele, N.; Gianninas, A.; Gonneau, A.; Kausch, W.; Lançon, A.; Noll, S.; Rauch, T.; Vinther, J.

    2014-08-01

    Context. While the near-infrared wavelength regime is becoming more and more important for astrophysics there is a marked lack of spectrophotometric standard star data that would allow the flux calibration of such data. Furthermore, flux calibrating medium- to high-resolution échelle spectroscopy data is challenging even in the optical wavelength range, because the available flux standard data are often too coarsely sampled. Aims: We will provide standard star reference data that allow users to derive response curves from 300 nm to 2500 nm for spectroscopic data of medium to high resolution, including those taken with échelle spectrographs. In addition we describe a method to correct for moderate telluric absorption without the need of observing telluric standard stars. Methods: As reference data for the flux standard stars we use theoretical spectra derived from stellar model atmospheres. We verify that they provide an appropriate description of the observed standard star spectra by checking for residuals in line cores and line overlap regions in the ratios of observed (X-shooter) spectra to model spectra. The finally selected model spectra are then corrected for remaining mismatches and photometrically calibrated using independent observations. The correction of telluric absorption is performed with the help of telluric model spectra. Results: We provide new, finely sampled reference spectra without telluric absorption for six southern flux standard stars that allow the users to flux calibrate their data from 300 nm to 2500 nm, and a method to correct for telluric absorption using atmospheric models. The reference model spectra described here are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/568/A9

  1. Comparison of the photothermal effects of 808nm gold nanorod and indocyanine green solutions using an 805nm diode laser

    NASA Astrophysics Data System (ADS)

    Hasanjee, Aamr M.; Zhou, Feifan; West, Connor; Silk, Kegan; Doughty, Austin; Bahavar, Cody F.; Chen, Wei R.

    2016-03-01

    Non-invasive laser immunotherapy (NLIT) is a treatment method for metastatic cancer which combines noninvasive laser irradiation with immunologically modified nanostructures to ablate a primary tumor and induce a systemic anti-tumor response. To further expand the development of NLIT, two different photosensitizing agents were compared: gold nanorods (GNR) with an optical absorption peak of 808 nm and indocyanine green (ICG) with an optical absorption peak of ~800 nm. Various concentrations of GNR and ICG solutions were irradiated at different power densities using an 805 nm diode laser, and the temperature of the solutions was monitored during irradiation using a thermal camera. For comparison, dye balls made up of a 1:1 volume ratio of gel solution to GNR or ICG solution were placed in phantom gels and were then irradiated using the 805 nm diode laser to imitate the effect of laser irradiation on in vivo tumors. Non-invasive laser irradiation of GNR solution for 2 minutes resulted in a maximum increase in temperature by 31.8 °C. Additionally, similar irradiation of GNR solution dye ball within phantom gel for 10 minutes resulted in a maximum temperature increase of 8.2 °C. Comparatively, non-invasive laser irradiation of ICG solution for 2 minutes resulted in a maximum increase in temperature by 28.0 °C. Similar irradiation of ICG solution dye ball within phantom gel for 10 minutes yielded a maximum temperature increase of only 3.4 °C. Qualitatively, these studies showed that GNR solutions are more effective photosensitizing agents than ICG solution.

  2. Writing time estimation of EB mask writer EBM-9000 for hp16nm/logic11nm node generation

    NASA Astrophysics Data System (ADS)

    Kamikubo, Takashi; Takekoshi, Hidekazu; Ogasawara, Munehiro; Yamada, Hirokazu; Hattori, Kiyoshi

    2014-10-01

    The scaling of semiconductor devices is slowing down because of the difficulty in establishing their functionality at the nano-size level and also because of the limitations in fabrications, mainly the delay of EUV lithography. While multigate devices (FinFET) are currently the main driver for scalability, other types of devices, such as 3D devices, are being realized to relax the scaling of the node. In lithography, double or multiple patterning using ArF immersion scanners is still a realistic solution offered for the hp16nm node fabrication. Other lithography candidates are those called NGL (Next Generation Lithography), such as DSA (Directed-Self-Assembling) or nanoimprint. In such situations, shot count for mask making by electron beam writers will not increase. Except for some layers, it is not increasing as previously predicted. On the other hand, there is another aspect that increases writing time. The exposure dose for mask writing is getting higher to meet tighter specifications of CD uniformity, in other words, reduce LER. To satisfy these requirements, a new electron beam mask writer, EBM-9000, has been developed for hp16nm/logic11nm generation. Electron optical system, which has the immersion lens system, was evolved from EBM-8000 to achieve higher current density of 800A/cm2. In this paper, recent shot count and dose trend are discussed. Also, writing time is estimated for the requirements in EBM-9000.

  3. 2 nm continuously tunable 488nm micro-integrated diode-laser-based SHG light source for Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Braune, M.; Maiwald, M.; Sumpf, B.; Tränkle, G.

    2016-04-01

    Raman spectroscopy in the visible spectral range is of great interest due to resonant Raman effects. Nevertheless, fluorescence and ambient light can mask the weak Raman lines. Shifted excitation Raman difference spectroscopy is a demonstrated tool to overcome this drawback. To apply this method, a light source with two alternating wavelengths is necessary. The spectral distance between these two wavelengths has to be adapted to the width of the Raman signal. According to the sample under investigation the width of the Raman signal could be in the range of 3 cm-1 - 12 cm-1. In this work, a micro-integrated light source emitting at 488 nm with a continuous wavelength tuning range up to 2 nm (83 cm-1) is presented. The pump source, a DFB laser emitting at 976 nm, and a periodically poled lithium niobate (PPLN) ridge waveguide crystal is used for the second harmonic generation (SHG). Both components are mounted on a μ-Peltier-element for temperature control. Here, a common wavelength tuning of the pump wavelength and the acceptance bandwidth of the SHG crystal via temperature is achieved. With the results the light source is suitable for portable Raman and SERDS experiments with a flexible spectral distance between both excitation wavelengths for SERDS with respect to the sample under investigation.

  4. Intra-cavity upconversion to 631 nm of images illuminated by an eye-safe ASE source at 1550 nm.

    PubMed

    Torregrosa, A J; Maestre, H; Capmany, J

    2015-11-15

    We report an image wavelength upconversion system. The system mixes an incoming image at around 1550 nm (eye-safe region) illuminated by an amplified spontaneous emission (ASE) fiber source with a Gaussian beam at 1064 nm generated in a continuous-wave diode-pumped Nd(3+):GdVO(4) laser. Mixing takes place in a periodically poled lithium niobate (PPLN) crystal placed intra-cavity. The upconverted image obtained by sum-frequency mixing falls around the 631 nm red spectral region, well within the spectral response of standard silicon focal plane array bi-dimensional sensors, commonly used in charge-coupled device (CCD) or complementary metal-oxide-semiconductor (CMOS) video cameras, and of most image intensifiers. The use of ASE illumination benefits from a noticeable increase in the field of view (FOV) that can be upconverted with regard to using coherent laser illumination. The upconverted power allows us to capture real-time video in a standard nonintensified CCD camera. PMID:26565863

  5. Spectroscopic Ellipsometry based Scatterometry enabling 193nm Litho and Etch process control for the 110nm technology node and beyond

    NASA Astrophysics Data System (ADS)

    Hingst, Thomas; Marschner, Thomas; Moert, Manfred; Homilius, Jan; Guevremont, Marco; Hopkins, John; Elazami, Assim

    2003-05-01

    In the production of sub 140nm electronic devices, CD metrology is becoming more critical due to the increased demands placed on process control. CD metrology using CD-SEM is approaching its limits especially with respect to precision, resolution and depth of field. Potentially, scatterometry can measure structures down to 50nm with the appropriate precision. Additionally, as scatterometry is a model based technique it allows a full reconstruction of the line profile and the film stack. In this work we use SE based scatterometry in the control of a 110nm DRAM WSix Gate process at the Litho and the Mask Open step. We demonstrate the use of a single trapezoid as a basic shape model in FEM and field mapping applications as well as in a high volume production test. The scatterometry results are compared to CD-SEM data. We show that for the GC Litho application, n&k variations in some of the stack materials do not affect the scatterometry CD measurement significantly.

  6. The Formation of IRIS Diagnostics. VII. The Formation of the OI 135.56 NM Line in the Solar Atmosphere

    NASA Astrophysics Data System (ADS)

    Lin, Hsiao-Hsuan; Carlsson, Mats

    2015-11-01

    The O i 135.56 nm line is covered by NASA's Interface Region Imaging Spectrograph (IRIS) small explorer mission which studies how the solar atmosphere is energized. We study here the formation and diagnostic potential of this line by means of non-local thermodynamic equilibrium modeling employing both 1D semi-empirical and 3D radiation magnetohydrodynamic models. We study the basic formation mechanisms and derive a quintessential model atom that incorporates essential atomic physics for the formation of the O i 135.56 nm line. This atomic model has 16 levels and describes recombination cascades through highly excited levels by effective recombination rates. The ionization balance O i/O ii is set by the hydrogen ionization balance through charge exchange reactions. The emission in the O i 135.56 nm line is dominated by a recombination cascade and the line is optically thin. The Doppler shift of the maximum emission correlates strongly with the vertical velocity in its line forming region, which is typically located at 1.0-1.5 Mm height. The total intensity of the line emission is correlated with the square of the electron density. Since the O i 135.56 nm line is optically thin, the width of the emission line is a very good diagnostic of non-thermal velocities. We conclude that the O i 135.56 nm line is an excellent probe of the middle chromosphere, and compliments other powerful chromospheric diagnostics of IRIS such as the Mg ii h & k lines and the C ii lines around 133.5 nm.

  7. Enhancing chemical reactions

    DOEpatents

    Morrey, John R.

    1978-01-01

    Methods of enhancing selected chemical reactions. The population of a selected high vibrational energy state of a reactant molecule is increased substantially above its population at thermal equilibrium by directing onto the molecule a beam of radiant energy from a laser having a combination of frequency and intensity selected to pump the selected energy state, and the reaction is carried out with the temperature, pressure, and concentrations of reactants maintained at a combination of values selected to optimize the reaction in preference to thermal degradation by transforming the absorbed energy into translational motion. The reaction temperature is selected to optimize the reaction. Typically a laser and a frequency doubler emit radiant energy at frequencies of .nu. and 2.nu. into an optical dye within an optical cavity capable of being tuned to a wanted frequency .delta. or a parametric oscillator comprising a non-centrosymmetric crystal having two indices of refraction, to emit radiant energy at the frequencies of .nu., 2.nu., and .delta. (and, with a parametric oscillator, also at 2.nu.-.delta.). Each unwanted frequency is filtered out, and each desired frequency is focused to the desired radiation flux within a reaction chamber and is reflected repeatedly through the chamber while reactants are fed into the chamber and reaction products are removed therefrom.

  8. Reactions of oriented molecules.

    PubMed

    Brooks, P R

    1976-07-01

    Beams of oriented molecules have been used to directly study geometrical requirements in chemical reactions. These studies have shown that reactivity is much greater in some orientations than others and demonstrated the existence of steric effects. For some reactions portions of the orientation results are in good accord with traditional views of steric hindrance, but for others it is clear that our chemical intuition needs recalibrating. Indeed, the information gained from simultaneously orienting the reactants and observing the scattering angle of the products may lead to new insights about the detailed mechanism of certain reactions. Further work must be done to extend the scope and detail of the studies described here. More detailed information is needed on the CH(3)I reaction and the CF(3)I reaction. The effects of alkyl groups of various sizes and alkali metals of various sizes are of interest. In addition, reactions where a long-lived complex is formed should be studied to see if orientation is important. Finally, it would be of interest to apply the technique to the sort of reactions that led to our interest in the first place: the S(N)2 displacements in alkyl halides where the fascinating Walden inversion occurs. PMID:17793988

  9. Mechanisms in knockout reactions

    NASA Astrophysics Data System (ADS)

    Bazin, D.; Charity, R. J.; de Souza, R. T.; Famiano, M. A.; Gade, A.; Henzl, V.; Henzlova, D.; Hudan, S.; Lee, J.; Lukyanov, S.; Lynch, W. G.; McDaniel, S.; Mocko, M.; Obertelli, A.; Rogers, A. M.; Sobotka, L. G.; Terry, J. R.; Tostevin, J. A.; Tsang, M. B.; Wallace, M. S.

    2009-10-01

    We report on the first detailed study of the mechanisms involved in knockout reactions, via a coincidence measurement of the residue and fast proton in one-proton knockout reactions, using the S800 spectrograph in combination with the HiRA detector array at the NSCL. Results on the reactions ^9Be(^9C,^8B+X)Y and ^9Be(^8B,^7Be+X)Y are presented. They are compared with theoretical predictions for both the diffraction (elastic breakup) and stripping (inelastic breakup) reaction mechanisms, as calculated in the eikonal model. The data shows a clear distinction between the two reaction mechanisms, and the observed respective proportions are very well reproduced by the reaction theory. This agreement supports the results of knockout reaction analyses and their applications to the spectroscopy of rare isotopes. In particular, this add considerable support to the use of the eikonal model as a quantitative tool, able, for example, to determine single-particle spectroscopic strengths in rare isotopes.

  10. An instrument to measure the solar spectrum from 170 to 3200 nm on board Spacelab

    NASA Technical Reports Server (NTRS)

    Thuiller, G.; Simon, P. C.; Pastiels, R.; Labs, D.; Meckel, H.

    1981-01-01

    This instrument, at the present time in development, will fly on board Spacelab I in May 1983. Other flights are foreseen during the following missions. The instrument is composed of three double monochromators covering the range 170 to 3200 nm. The spectrometers have bandpasses of 1 nm up to 900 nm and 20 nm from 850 to 3200 nm with an accuracy 1/100 nm. Calibration lamps are included in the instrument to monitor any change of its sensitivity and wavelength scale.

  11. Temperature dependence of the OH + CINO reaction: evidence for two competing reaction channels

    SciTech Connect

    Finlayson-Pitts, B.J.; Ezell, M.J.; Grant, C.E.

    1986-01-02

    The temperature dependence of the reaction of OH with nitrosyl chloride, CINO, has been studied from 263 to 373 K in a fast-flow discharge system. The decay of OH in the presence of excess CINO was followed by resonance fluorescence at 309.5 nm. The total pressure was 1.05 +/- 0.05 torr in He as the carrier gas. The rate constant increases both above and below room temperature suggesting the existence of two competing reaction paths, a direct abstraction reaction, HO + CINO ..-->.. HOCl + NO (1a) and one involving formation of an intermediate complex, HO + ClNO in equilibrium (HO x ClNO)* ..-->.. HONO + Cl (1b). This supports the interpretation of the room temperature product data of Poulet and co-workers. 13 references, 4 figures, 1 table.

  12. Hypersensitivity reactions to corticosteroids.

    PubMed

    Vatti, Rani R; Ali, Fatima; Teuber, Suzanne; Chang, Christopher; Gershwin, M Eric

    2014-08-01

    Hypersensitivity reactions to corticosteroids (CS) are rare in the general population, but they are not uncommon in high-risk groups such as patients who receive repeated doses of CS. Hypersensitivity reactions to steroids are broadly divided into two categories: immediate reactions, typically occurring within 1 h of drug administration, and non-immediate reactions, which manifest more than an hour after drug administration. The latter group is more common. We reviewed the literature using the search terms "hypersensitivity to steroids, adverse effects of steroids, steroid allergy, allergic contact dermatitis, corticosteroid side effects, and type I hypersensitivity" to identify studies or clinical reports of steroid hypersensitivity. We discuss the prevalence, mechanism, presentation, evaluation, and therapeutic options in corticosteroid hypersensitivity reactions. There is a paucity of literature on corticosteroid allergy, with most reports being case reports. Most reports involve non-systemic application of corticosteroids. Steroid hypersensitivity has been associated with type I IgE-mediated allergy including anaphylaxis. The overall prevalence of type I steroid hypersensitivity is estimated to be 0.3-0.5%. Allergic contact dermatitis (ACD) is the most commonly reported non-immediate hypersensitivity reaction and usually follows topical CS application. Atopic dermatitis and stasis dermatitis of the lower extremities are risk factors for the development of ACD from topical CS. Patients can also develop hypersensitivity reactions to nasal, inhaled, oral, and parenteral CS. A close and detailed evaluation is required for the clinician to confirm the presence of a true hypersensitivity reaction to the suspected drug and choose the safest alternative. Choosing an alternative CS is not only paramount to the patient's safety but also ameliorates the worry of developing an allergic, and potentially fatal, steroid hypersensitivity reaction. This evaluation becomes

  13. Aerosol Extinction and Single Scattering Albedo Downwind of the Summer 2008 California Wildfires Measured With Photoacoustic Spectrometers and Sunphotometers From 355 nm to 1047 nm.

    NASA Astrophysics Data System (ADS)

    Arnott, W. P.; Gyawali, M. S.; Arnold, I. J.

    2008-12-01

    Hundreds of wildfires in Northern California were sparked by lightning during the summer of 2008, resulting in downwind smoke for much of June and July associated with the flaming and smoldering stages of the fires. These fires are consistent with a growing trend towards increasing biomass burning worldwide. Climate impacts from the smoke depend critically on the smoke amount and aerosol optical properties. We report comparison of aerosol optics measurements in Reno Nevada made during the very smoky summer month of July with the relatively clean, average month of August. Photoacoustic instruments equipped with integrating nephelometers were used to measure aerosol light scattering and absorption at wavelengths of 355 nm, 405 nm, 532 nm, 870 nm, and 1047 nm. Total aerosol optical depth was measured with a sun photometer operating at 430nm, 470nm, 530nm, 660nm, 870nm and 950nm. A spectrometer based sun photometer with an operating range from 390nm to 880 nm was also used for a few days as well. These measurements document the intensity of the smoke optical impacts downwind. They are processed further to reveal a strong variation of the aerosol light absorption on wavelength, indicating the presence of light absorbing organic material and perhaps wavelength dependent absorption caused by black carbon particles coated with organic and inorganic particulate matter. On the day with most smoke in Reno (July 10, 2008) Angstrom coefficients for absorption as high as 3.6 were found for wavelengths of 405 nm and 870 nm, with the corresponding single scattering albedo near 0.92 at 405 nm. Aerosol optical depths of 3.5 were found for 430 nm on July 10th from the sun photometer measurements. A roughly fourfold increase in aerosol optical quantities was observed between the months of July and August 2008, attesting to the large average effects of biomass aerosols from the California wildfires.

  14. NEUTRONIC REACTION SYSTEM

    DOEpatents

    Wigner, E.P.

    1963-09-01

    A nuclear reactor system is described for breeding fissionable material, including a heat-exchange tank, a high- and a low-pressure chamber therein, heat- exchange tubes connecting these chambers, a solution of U/sup 233/ in heavy water in a reaction container within the tank, a slurry of thorium dioxide in heavy water in a second container surrounding the first container, an inlet conduit including a pump connecting the low pressure chamber to the reaction container, an outlet conduit connecting the high pressure chamber to the reaction container, and means of removing gaseous fission products released in both chambers. (AEC)

  15. Reduced nonlinearities in 100-nm high SOI waveguides

    NASA Astrophysics Data System (ADS)

    Lacava, C.; Marchetti, R.; Vitali, V.; Cristiani, I.; Giuliani, G.; Fournier, M.; Bernabe, S.; Minzioni, P.

    2016-03-01

    Here we show the results of an experimental analysis dedicated to investigate the impact of optical non linear effects, such as two-photon absorption (TPA), free-carrier absorption (FCA) and free-carrier dispersion (FCD), on the performance of integrated micro-resonator based filters for application in WDM telecommunication systems. The filters were fabricated using SOI (Silicon-on-Insulator) technology by CEA-Leti, in the frame of the FP7 Fabulous Project, which aims to develop low-cost and high-performance integrated optical devices to be used in new generation passive optical- networks (NG-PON2). Different designs were tested, including both ring-based structures and racetrack-based structures, with single-, double- or triple- resonator configuration, and using different waveguide cross-sections (from 500 x 200 nm to 825 x 100 nm). Measurements were carried out using an external cavity tunable laser source operating in the extended telecom bandwidth, using both continuous wave signals and 10 Gbit/s modulated signals. Results show that the use 100-nm high waveguide allows reducing the impact of non-linear losses, with respect to the standard waveguides, thus increasing by more than 3 dB the maximum amount of optical power that can be injected into the devices before causing significant non-linear effects. Measurements with OOK-modulated signals at 10 Gbit/s showed that TPA and FCA don't affect the back-to-back BER of the signal, even when long pseudo-random-bit-sequences (PRBS) are used, as the FCD-induced filter-detuning increases filter losses but "prevents" excessive signal degradation.

  16. Effect of UVB 311 nm irradiation on normal human skin.

    PubMed

    Viac, J; Goujon, C; Misery, L; Staniek, V; Faure, M; Schmitt, D; Claudy, A

    1997-06-01

    Ultraviolet radiation B (UVB) on the skin induces erythema, inflammation and modifications of the immune system. These changes have been reported after excessive short-term or long-term exposure to broad spectrum UVB. In this study, we examined the effects of local repetitive UVB irradiation of 311 nm wavelength on the skin of seven young volunteers. Skin biopsies were taken before and after UVB irradiation, and we immunohistochemically analyzed the expression of CD1a and HLA-DR antigens of Langerhans cells (LC), the possible infiltration of dermis/epidermis by CD11b macrophages, the modifications or the induction of intercellular adhesion molecule-1 (ICAM-1), E-selectin and vascular cell adhesion molecule-1 (VCAM-1) involved in the binding of leukocytes to the endothelial surface and the development of perivascular infiltrates of LFA-1+ mononuclear cells. We also determined the expression of substance P receptors (SPR) using biotinylated substance P (SPB). Exposure of UVB 311 nm induced a drastic reduction of CD1a+ cells and a moderate increase of HLA-DR+ dendritic cells in the epidermis without infiltration by CD11b macrophages. An increase of the binding of SPB to upper layer epidermal cells was noted in five of seven biopsies. In the dermis, vessel-associated ICAM-1 expression increased and an induction of E-selectin occurred on nearly 20 to 40% of endothelial cells, but VCAM-1 expression remained undetectable. The percentage of LFA-1+ cells did not change significantly after irradiation. These observations may be compatible with a selective role of UVB 311 nm on the skin immune response. PMID:9372527

  17. Quasi-cw tissue transillumination at 1064 nm

    NASA Astrophysics Data System (ADS)

    Bernini, Umberto; Ramaglia, Antonio; Russo, Paolo

    1997-08-01

    An extended series of transillumination experiments has been performed in vitro on animal samples (bovine muscle, up to 30- mm-thick; chicken wing and quail femur, 12-mm-thick) and in vivo on the human hand (thickness, about 20 mm), using a pulsed light source (7 ns, about 10-4 J/pulse, 10 Hz rep rate) from a collimated (1.2 m) Nd:YAG laser beam (1064 nm). A PIN photodiode connected to a digital oscilloscope was used to measure the maximum intensity of the beam pulse transmitted through the sample (i.e., no temporal discrimination of the output signal was attempted) while it was scanned across the source/detector assembly. One dimensional scans were performed on bovine muscle samples in which thin metallic test objects were embedded, in order to study the spatial resolution of the technique (for bovine muscle at 1064 nm, absorption and reduced scattering coefficients are reported to be about 1 cm-1 and 3 cm-1, respectively). The measured spatial resolution was as good as 3.6 mm in 30 mm of tissue thickness. In the two-dimensional scans of the chicken and quail sample, fat and bone tissues can be easily seen with good resolution, whereas imaging of the middle finger of a human hand shows cartilaginoid and bone tissue with 1 - 2 mm resolution. Hence, this simple collimated quasi-cw technique gives significantly better results for tissue imaging than pure cw transillumination. Use of (pulsed) light above 1000 nm and a high energy content per pulse are supposed to explain the positive experimental findings.

  18. 10nm three-dimensional CD-SEM metrology

    NASA Astrophysics Data System (ADS)

    Vladár, András. E.; Villarrubia, John S.; Chawla, Jasmeet; Ming, Bin; Kline, Joseph R.; List, Scott; Postek, Michael T.

    2014-04-01

    The shape and dimensions of a challenging pattern have been measured using a model-based library scanning electron microscope (MBL SEM) technique. The sample consisted of a 4-line repeating pattern. Lines were narrow (10 nm), asymmetric (different edge angles and significant rounding on one corner but not the other), and situated in a complex neighborhood, with neighboring lines as little as 10 nm or as much as 28 nm distant. The shape cross-section determined by this method was compared to transmission electron microscopy (TEM) and critical dimension small angle x-ray scattering (CD-SAXS) measurements of the same sample with good agreement. A recently-developed image composition method was used to obtain sharp SEM images, in which blur from vibration and drift were minimized. A Monte Carlo SEM simulator (JMONSEL) produced a model-based library that was interpolated to produce the best match to measured SEM images. Three geometrical and instrument parameterizations were tried. The first was a trapezoidal geometry. In the second one corner was significantly rounded. In the last, the electron beam was permitted to arrive with stray tilt. At each stage, the fit to the data improved by a statistically significant amount, demonstrating that the measurement remained sensitive to the new parameter. Because the measured values represent the average unit cell, the associated repeatabilities are at the tenths of a nanometer level, similar to scatterometry and other area-averaging techniques, but the SEM's native high spatial resolution also permitted observation of defects and other local departures from the average.

  19. Transcanalicular laser dacryocystorhinostomy using low energy 810 nm diode laser

    PubMed Central

    Gupta, Sanjiv K.; Kumar, Ajai; Agarwal, Swati; Pandey, Paritosh

    2012-01-01

    Background: Hypertrophic scarring may be a cause of failure after transcanalicular laser dacryocystorhinostomy (DCR) surgery. This hypertrophic scarring results from tissue charring and excessive coagulation, which may be caused by the high laser energy. We have evaluated the use of low energy settings to prevent hypertrophic scarring, for a successful outcome. Aims: To perform and evaluate transcanalicular laser DCR using low energy 810 nm diode laser. Design: Interventional, non-comparative, case series. Materials and Methods: Patients with nasolacrimal duct obstruction and chronic dacryocystitis, who needed DCR, and were fit for surgery under local anesthesia, were recruited to undergo transcanalicular laser DCR using a 810 nm diode laser. The outcome was measured by the patency of the lacrimal passage, as indicated by the relief in the symptoms and the patency on syringing at the last follow-up. The surgical time and surgical complications were noted. Statistical Analysis Used: Descriptive analysis. Results: The study included 94 patients. The average age was 30.1 years (range 15 - 69 years). Seventy (74.4%) patients were female. Eight patients had failed external DCR. Per-operative patency of the passage was obtained in all the patients. Average surgical time was seven minutes (5 – 18 minutes). At the end of the study period of one year, a successful outcome was seen in 85 patients (90.5%). There were eight patients of previous failed DCR surgeries, and six of them achieved a cure at the end of follow-up. Conclusions: Transcanalicular Laser DCR can be safely performed using a low power 810 nm diode laser. The surgery is elegant, minimally invasive, allows fast rehabilitation, and has an excellent success rate. PMID:23439888

  20. Development status of a 157-nm full-field scanner

    NASA Astrophysics Data System (ADS)

    Nakano, Hitoshi; Hata, Hideo; Nogawa, Hideki; Deguchi, Nobuyoshi; Kohno, Michio; Chiba, Yuji

    2003-06-01

    157 nm lithography has made further progress over the past year, steadily advancing towards the realization of the 65 nm era. In particular, exposure tools have moved on to the assembly phase, with new functions and performance now under evaluation. This paper presents our technical progress in our 157nm full field exposure tool, focusing on two key technologies: projection optics and environmental control with highly purified gasses. The high NA projection optics were designed to meet accelerating demands for smaller geometries. A catadioptric system with a line-selected laser was chosen to solve the problem of chromatic aberrations. The birefringence effect caused by CaF2 has been reduced to acceptable levels by clocking and combining <111> and <100> oriented crystals. Polishing and optical coatings consisting of glass materials were completed at targeted accuracy. At the present time, assembly and tuning of the projection optics is being performed. A simulation based on the inspection data from each production step predicts that the desired image performance will be attained. The total efficiency of the exposure system is expected to be higher than previously announced, due to the improvement of both CaF2 transmittance and AR/HR coatings. One of two keys issues in environmental control is to purge the projection optics which are permanently sealed. Purging performance was tested using a mockup of the projection optics. The second issue is to purge the areas around reticles and wafers which are continually carried into and out of the exposure system. Using the actual platform, the wafer and reticle purging performance was evaluated. It has been demonstrated that both of our purging systems are effective in keeping the environment at minimum contamination levels. This contributes to the increase of throughput.

  1. 32nm design rule and process exploration flow

    NASA Astrophysics Data System (ADS)

    Zhang, Yunqiang; Cobb, Jonathan; Yang, Amy; Li, Ji; Lucas, Kevin; Sethi, Satyendra

    2008-10-01

    Semiconductor manufacturers spend hundreds of millions of dollars and years of development time to create a new manufacturing process and to design frontrunner products to work on the new process. A considerable percentage of this large investment is aimed at producing the process design rules and related lithography technology to pattern the new products successfully. Significant additional cost and time is needed in both process and design development if the design rules or lithography strategy must be modified. Therefore, early and accurate prediction of both process design rules and lithography options is necessary for minimizing cost and timing in semiconductor development. This paper describes a methodology to determine the optimum design rules and lithography conditions with high accuracy early in the development lifecycle. We present results from the 32nm logic node but the methodology can be extended to the 22nm node or any other node. This work involves: automated generation of extended realistic logic test layouts utilizing programmed teststructures for a variety of design rules; determining a range of optical illumination and process conditions to test for each critical design layer; using these illumination conditions to create a extrapolatable process window OPC model which is matched to rigorous TCAD lithography focus-exposure full chemically amplified resist models; creating reticle enhancement technique (RET) recipes which are flexible enough to be used over a variety of design rule and illumination conditions; OPC recipes which are flexible enough to be used over a variety of design rule and illumination conditions; and OPC verification to find, categorize and report all patterning issues found in the different design and illumination variations. In this work we describe in detail the individual steps in the methodology, and provide results of its use for 32nm node design rule and process optimization.

  2. 28nm node process optimization: a lithography centric view

    NASA Astrophysics Data System (ADS)

    Seltmann, Rolf

    2014-10-01

    Many experts claim that the 28nm technology node will be the most cost effective technology node forever. This results from primarily from the cost of manufacturing due to the fact that 28nm is the last true Single Patterning (SP) node. It is also affected by the dramatic increase of design costs and the limited shrink factor of the next following nodes. Thus, it is assumed that this technology still will be alive still for many years. To be cost competitive, high yields are mandatory. Meanwhile, leading edge foundries have optimized the yield of the 28nm node to such a level that that it is nearly exclusively defined by random defectivity. However, it was a long way to go to come to that level. In my talk I will concentrate on the contribution of lithography to this yield learning curve. I will choose a critical metal patterning application. I will show what was needed to optimize the process window to a level beyond the usual OPC model work that was common on previous nodes. Reducing the process (in particular focus) variability is a complementary need. It will be shown which improvements were needed in tooling, process control and design-mask-wafer interaction to remove all systematic yield detractors. Over the last couple of years new scanner platforms were introduced that were targeted for both better productivity and better parametric performance. But this was not a clear run-path. It needed some extra affords of the tool suppliers together with the Fab to bring the tool variability down to the necessary level. Another important topic to reduce variability is the interaction of wafer none-planarity and lithography optimization. Having an accurate knowledge of within die topography is essential for optimum patterning. By completing both the variability reduction work and the process window enhancement work we were able to transfer the original marginal process budget to a robust positive budget and thus ensuring high yield and low costs.

  3. A Photo-Triggered Traceless Staudinger-Bertozzi Ligation Reaction.

    PubMed

    Hu, Peng; Feng, Tianshi; Yeung, Chi-Chung; Koo, Chi-Kin; Lau, Kai-Chung; Lam, Michael H W

    2016-08-01

    The use of light to control the course of a chemical/biochemical reaction is an attractive idea because of its ease of administration with high precision and fine spatial resolution. Staudinger ligation is one of the commonly adopted conjugation processes that involve a spontaneous reaction between azides and arylphosphines to form iminophosphoranes, which further hydrolyze to give stable amides. We designed an anthracenylmethyl diphenylphosphinothioester (1) that showed promising Staudinger ligation reactivity upon photo-excitation. Broadband photolysis at 360-400 nm in aqueous organic solvents induced heterolytic cleavage of its anthracenylmethyl-phosphorus bond, releasing a diphenylphosphinothioester (2) as an efficient traceless Staudinger-Bertozzi ligation reagent. The quantum yield of such a photo-induced heterolytic bond-cleavage at the optimal wavelength of photolysis (376 nm) at room temperature is ≥0.07. This work demonstrated the feasibility of photocaging arylphosphines to realize the photo-triggering of the Staudinger ligation reaction. PMID:27123884

  4. Towards Using DNAzyme in Sub-20 nm Lithography

    NASA Astrophysics Data System (ADS)

    Dirar, Qassim

    DNAzyme is a unique molecule with applications ranging from gene regulation to molecular machines. Another attractive venue for the use of DNAzyme is next generation lithography, sub-20 nm lithography, harnessing the unique features of specific recognition and self-assembly. Tools to achieve that goal are discussed and experimental procedures were presented. Loading DNAzyme on gold nanoparticles, depositing self-assembled monolayers and DNA patterning using soft lithographic techniques are tools that are explored. To support the findings, different characterization techniques are employed.

  5. Photodissociation dynamics of O 3- at 523 nm

    NASA Astrophysics Data System (ADS)

    Garner, M. C.; Sherwood, C. R.; Hanold, K. A.; Continetti, R. E.

    1996-01-01

    The photodissociation dynamics of O 3- at 523 nm have been studied using fast-ion-beam translational energy spectroscopy. Translational energy and angular distributions of coincident O - + O 2 products from the process O 3- + hv → O - + O 2 were measured. O 3- was generated by electron-impact in a pulsed beam from two precursors — neat O 2 and a seeded beam of O 3. The observed photodissociation dynamics are very different in the two cases, indicating a great difference in internal excitation of ozonide in the two sources.

  6. A 65 nm CMOS LNA for Bolometer Application

    NASA Astrophysics Data System (ADS)

    Huang, Tom Nan; Boon, Chirn Chye; Zhu, Forest Xi; Yi, Xiang; He, Xiaofeng; Feng, Guangyin; Lim, Wei Meng; Liu, Bei

    2016-04-01

    Modern bolometers generally consist of large-scale arrays of detectors. Implemented in conventional technologies, such bolometer arrays suffer from integrability and productivity issues. Recently, the development of CMOS technologies has presented an opportunity for the massive production of high-performance and highly integrated bolometers. This paper presents a 65-nm CMOS LNA designed for a millimeter-wave bolometer's pre-amplification stage. By properly applying some positive feedback, the noise figure of the proposed LNA is minimized at under 6 dB and the bandwidth is extended to 30 GHz.

  7. YSGG 2790-nm superficial ablative and fractional ablative laser treatment.

    PubMed

    Smith, Kevin C; Schachter, G Daniel

    2011-05-01

    The 2790-nm wavelength YSGG laser was introduced for aesthetic purposes under the trade name Pearl by Cutera in 2007. In clinical use, the Pearl superficial resurfacing laser has proved effective and well tolerated for the correction of superficial brown epidermal dyschromia and superficial fine lines and scars, and the Pearl Fractional laser produces excellent improvement in both dyschromia and improvement of deeper lines and moderately deep acne scarring. The two laser treatments can be combined in a single treatment session on different parts of the face or on the entire face, depending on patient needs and priorities. PMID:21763987

  8. 100 W average power femtosecond laser at 343 nm.

    PubMed

    Rothhardt, Jan; Rothhardt, Carolin; Müller, Michael; Klenke, Arno; Kienel, Marco; Demmler, Stefan; Elsmann, Tino; Rothhardt, Manfred; Limpert, Jens; Tünnermann, Andreas

    2016-04-15

    We present a femtosecond laser system delivering up to 100 W of average power at 343 nm. The laser system employs a Yb-based femtosecond fiber laser and subsequent second- and third-harmonic generation in beta barium borate (BBO) crystals. Thermal gradients within these BBO crystals are mitigated by sapphire heat spreaders directly bonded to the front and back surface of the crystals. Thus, a nearly diffraction-limited beam quality (M2 < 1.4) is achieved, despite the high thermal load to the nonlinear crystals. This laser source is expected to push many industrial and scientific applications in the future. PMID:27082370

  9. Magnetic configurations in 160 520-nm-diameter ferromagnetic rings

    NASA Astrophysics Data System (ADS)

    Castaño, F. J.; Ross, C. A.; Eilez, A.; Jung, W.; Frandsen, C.

    2004-04-01

    The remanent states and hysteretic behavior of thin-film magnetic rings has been investigated experimentally and by micromagnetic modeling. Rings of diameters 160 520 nm, made from Co using lift-off processing, show three distinct remanent states: a vortex state, an “onion” state with two head-on walls, and a “twisted” state containing a 360° wall. The range of stability of these states varies with ring geometry, with smaller width rings showing higher switching fields and greater variability.

  10. Spectroscopy of Pluto, 380-930 Nm at Six Longitudes

    NASA Technical Reports Server (NTRS)

    Cruikshank, D. P.; Pinilla-Alonso, N.; Lorenzi, V.; Grundy, William; Licandro, J.; Binzel, R. P.

    2014-01-01

    We have obtained spectra of the Pluto-Charon pair (unresolved) in the wavelength range 380-930 nm with resolution approx..450 at six roughly equally spaced longitudes. The data were taken in May and June, 2014, with the 4.2-m Isaac Newton Telescope at Roque de Los Muchachos Observatory in the Canary Islands, using the ACAM (auxiliary-port camera) in spectrometer mode, and using two solar analog stars. The new spectra clearly show absorption bands of solid CH4 at 620, 728, and 850-910 nm, which were known from earlier work. The 620-nm CH4 band is intrinsically very weak, and its appearance indicates a long optical path-length through the ice. This is especially true if it arises from CH4 dissolved in N2 ice. Earlier work (Owen et al. Science 261, 745, 1993) on the near-infrared spectrum of Pluto (1-2.5 microns) has shown that the CH4 bands are shifted to shorter wavelengths because the CH4 occurs as a solute in beta-phase crystalline N2. The optical path-length through the N2 crystals must be on the order of several cm to produce the N2 band observed at 2.15 microns. The new spectra exhibit a pronounced red slope across the entire wavelength range; the slope is variable with longitude, and differs in a small but significant way from that measured at comparable longitudes by Grundy & Fink (Icarus 124, 329, 1996) in their 15-year study of Pluto's spectrum (500-1000 nm). The new spectra will provide an independent means for calibrating the color filter bands on the Multispectral Visible Imaging Camera (MVIC) (Reuter et al. Space Sci. Rev. 140, 129, 2008) on the New Horizons spacecraft, which will encounter the Pluto-Charon system in mid-2015. They will also form the basis of modeling the spectrum of Pluto at different longitudes to help establish the nature of the non-ice component(s) of Pluto's surface. It is presumed that the non-ice component is the source of the yellow-red coloration of Pluto, which is known to be variable across the surface.

  11. Spectroscopy of Pluto at six longitudes, 380-930 nm

    NASA Astrophysics Data System (ADS)

    Cruikshank, Dale P.; Pinilla-Alonso, Noemi; Lorenzi, Vania; Grundy, Will M.; Licandro, Javier; Binzel, Richard P.

    2014-11-01

    We have obtained spectra of the Pluto-Charon pair (unresolved) in the wavelength range 380-930 nm with resolution ~450 at six roughly equally spaced longitudes. The data were taken in May and June, 2014, with the 4.2-m Isaac Newton Telescope at Roque de Los Muchachos Observatory in the Canary Islands, using the ACAM (auxiliary-port camera) in spectrometer mode, and using two solar analog stars. The new spectra clearly show absorption bands of solid CH4 at 620, 728, and 850-910 nm, which were known from earlier work. The 620-nm CH4 band is intrinsically very weak, and its appearance indicates a long optical pathlength through the ice. This is especially true if it arises from CH4 dissolved in N2 ice. Earlier work (Owen et al. Science 261, 745, 1993) on the near-infrared spectrum of Pluto (1-2.5 µm) has shown that the CH4 bands are shifted to shorter wavelengths because the CH4 occurs as a solute in beta-phase crystalline N2. The optical pathlength through the N2 crystals must be on the order of several cm to produce the N2 band observed at 2.15 µm. The new spectra exhibit a pronounced red slope across the entire wavelength range; the slope is variable with longitude, and differs in a small but significant way from that measured at comparable longitudes by Grundy & Fink (Icarus 124, 329, 1996) in their 15-year study of Pluto’s spectrum (500-1000 nm). The new spectra will provide an independent means for calibrating the color filter bands on the Multispectral Visible Imaging Camera (MVIC) (Reuter et al. Space Sci. Rev. 140, 129, 2008) on the New Horizons spacecraft, which will encounter the Pluto-Charon system in mid-2015. They will also form the basis of modeling the spectrum of Pluto at different longitudes to help establish the nature of the non-ice component(s) of Pluto’s surface. It is presumed that the non-ice component is the source of the yellow-red coloration of Pluto, which is known to be variable across the surface.

  12. High bit rate germanium single photon detectors for 1310nm

    NASA Astrophysics Data System (ADS)

    Seamons, J. A.; Carroll, M. S.

    2008-04-01

    There is increasing interest in development of high speed, low noise and readily fieldable near infrared (NIR) single photon detectors. InGaAs/InP Avalanche photodiodes (APD) operated in Geiger mode (GM) are a leading choice for NIR due to their preeminence in optical networking. After-pulsing is, however, a primary challenge to operating InGaAs/InP single photon detectors at high frequencies1. After-pulsing is the effect of charge being released from traps that trigger false ("dark") counts. To overcome this problem, hold-off times between detection windows are used to allow the traps to discharge to suppress after-pulsing. The hold-off time represents, however, an upper limit on detection frequency that shows degradation beginning at frequencies of ~100 kHz in InGaAs/InP. Alternatively, germanium (Ge) single photon avalanche photodiodes (SPAD) have been reported to have more than an order of magnitude smaller charge trap densities than InGaAs/InP SPADs2, which allowed them to be successfully operated with passive quenching2 (i.e., no gated hold off times necessary), which is not possible with InGaAs/InP SPADs, indicating a much weaker dark count dependence on hold-off time consistent with fewer charge traps. Despite these encouraging results suggesting a possible higher operating frequency limit for Ge SPADs, little has been reported on Ge SPAD performance at high frequencies presumably because previous work with Ge SPADs has been discouraged by a strong demand to work at 1550 nm. NIR SPADs require cooling, which in the case of Ge SPADs dramatically reduces the quantum efficiency of the Ge at 1550 nm. Recently, however, advantages to working at 1310 nm have been suggested which combined with a need to increase quantum bit rates for quantum key distribution (QKD) motivates examination of Ge detectors performance at very high detection rates where InGaAs/InP does not perform as well. Presented in this paper are measurements of a commercially available Ge APD

  13. INITIAL GAIN MEASUREMENTS OF A 800 NM SASE FEL, VISA.

    SciTech Connect

    FRIGOLA,P.; MUROKH,A.; ET AL; BABZIEN,M.; BEN-ZVI,I.; JOHNSON,E.; MALONE,R.

    2000-08-13

    The VISA (Visible to Infrared SASE Amplifier) FEL is designed to obtain high gain at a radiation wavelength of 800nm. The FEL uses the high brightness electron beam of the Accelerator Test Facility (ATF), with energy of 72MeV. VISA uses a novel, 4 m long, strong focusing undulator with a gap of 6mm and a period of 1.8cm. To obtain large gain the beam and undulator axis have to be aligned to better than 50{micro}m. Results from initial measurements on the alignment, gain, and spectrum will be presented and compared to theoretical calculations and simulations.

  14. Initial Gain Measurements of a 800nm SASE FEL, VISA

    SciTech Connect

    Carr, Roger

    2002-08-14

    The VISA (Visible to Infrared SASE Amplifier) FEL is designed to obtain high gain at a radiation wavelength of 800nm. The FEL uses the high brightness electron beam of the Accelerator Test Facility (ATF), with energy of 72MeV. VISA uses a novel, 4 m long, strong focusing undulator with a gap of 6mm and a period of 1.8cm. To obtain large gain the beam and undulator axis have to be aligned to better than 50{micro}m. Results from initial measurements on the alignment, gain, and spectrum will be presented and compared to theoretical calculations and simulations.

  15. Initial gain measurements of an 800 nm SASE FEL, VISA

    NASA Astrophysics Data System (ADS)

    Frigola, P.; Murokh, A.; Musumeci, P.; Pellegrini, C.; Reiche, S.; Rosenzweig, J.; Tremaine, A.; Babzien, M.; Ben-Zvi, I.; Johnson, E.; Malone, R.; Rakowsky, G.; Skaritka, J.; Wang, X. J.; Van Bibber, K. A.; Bertolini, L.; Hill, J. M.; Le Sage, G. P.; Libkind, M.; Toor, A.; Carr, R.; Cornacchia, M.; Klaisner, L.; Nuhn, H.-D.; Ruland, R.; Nguyen, D. C.

    2001-12-01

    The Visible to Infrared SASE Amplifier (VISA) FEL is designed to obtain high gain at a radiation wavelength of 800 nm. The FEL uses the high brightness electron beam of the Accelerator Test Facility (ATF), with energy of 72 MeV. VISA uses a novel, 4 m long, strong focusing undulator with a gap of 6 mm and a period of 1.8 cm. To obtain large gain the beam and undulator axis have to be aligned to better than 5 μm. Results from initial measurements on the alignment, gain, and spectrum will be presented and compared to theoretical calculations and simulations.

  16. Characterization of an 800 nm SASE FEL at Saturation

    SciTech Connect

    Nuhn, Heinz-Dieter

    2002-11-13

    VISA (Visible to Infrared SASE Amplifier) is an FEL (Free Electron Laser) designed to saturate at a radiation wavelength of 800 nm within a 4-m long, strong focusing undulator. Large gain is achieved by driving the FEL with the 72 MeV, high brightness beam of BNL's Accelerator Test Facility (ATF). We present measurements that demonstrate saturation in addition to the frequency spectrum of the FEL radiation. Energy, gain length and spectral characteristics are compared and shown to agree with simulation and theoretical predictions.

  17. Ocular safety limits for 1030nm femtosecond laser cataract surgery

    NASA Astrophysics Data System (ADS)

    Wang, Jenny; Sramek, Christopher; Paulus, Yannis M.; Lavinsky, Daniel; Schuele, Georg; Anderson, Dan; Dewey, David; Palanker, Daniel V.

    2013-03-01

    Application of femtosecond lasers to cataract surgery has added unprecedented precision and reproducibility but ocular safety limits for the procedure are not well-quantified. We present an analysis of safety during laser cataract surgery considering scanned patterns, reduced blood perfusion, and light scattering on residual bubbles formed during laser cutting. Experimental results for continuous-wave 1030 nm irradiation of the retina in rabbits are used to calibrate damage threshold temperatures and perfusion rate for our computational model of ocular heating. Using conservative estimates for each safety factor, we compute the limits of the laser settings for cataract surgery that optimize procedure speed within the limits of retinal safety.

  18. Photoabsorption cross sections of OH at 115-183 nm

    NASA Technical Reports Server (NTRS)

    Nee, J. B.; Lee, L. C.

    1984-01-01

    The absorption spectrum for OH was obtained in the 115-183 nm region. The OH radicals were produced by a pulse discharge of trace H2O in few torr of Ar. Absorption cross sections were obtained by calibration with absorption of the OH (X 2 Pi to A 2 Sigma +) transition. The features in the absorption spectrum are correlated with the excited states 1 2 Sigma -, D 2 Sigma -, 1 2 Delta, B 2 Sigma + and possibly others calculated by van Dishoeck, Langhoff, and Dalgarno. The measured cross sections are comparable with the calculated values.

  19. Development of high coherence high power 193nm laser

    NASA Astrophysics Data System (ADS)

    Tanaka, Satoshi; Arakawa, Masaki; Fuchimukai, Atsushi; Sasaki, Yoichi; Onose, Takashi; Kamba, Yasuhiro; Igarashi, Hironori; Qu, Chen; Tamiya, Mitsuru; Oizumi, Hiroaki; Ito, Shinji; Kakizaki, Koji; Xuan, Hongwen; Zhao, Zhigang; Kobayashi, Yohei; Mizoguchi, Hakaru

    2016-03-01

    We have been developing a hybrid 193 nm ArF laser system that consists of a solid state seeding laser and an ArF excimer laser amplifier for power-boosting. The solid state laser consists of an Yb-fiber-solid hybrid laser system and an Er-fiber laser system as fundamentals, and one LBO and three CLBO crystals for frequency conversion. In an ArF power amplifier, the seed laser passes through the ArF gain media three times, and an average power of 110 W is obtained. As a demonstration of the potential applications of the laser, an interference exposure test is performed.

  20. Novel high sensitivity EUV photoresist for sub-7nm node

    NASA Astrophysics Data System (ADS)

    Nagai, Tomoki; Nakagawa, Hisashi; Naruoka, Takehiko; Tagawa, Seiichi; Oshima, Akihiro; Nagahara, Seiji; Shiraishi, Gosuke; Yoshihara, Kosuke; Terashita, Yuichi; Minekawa, Yukie; Buitrago, Elizabeth; Ekinci, Yasin; Yildirim, Oktay; Meeuwissen, Marieke; Hoefnagels, Rik; Rispens, Gijsbert; Verspaget, Coen; Maas, Raymond

    2016-03-01

    Extreme ultraviolet lithography (EUVL) has been recognized as the most promising candidate for the manufacture of semiconductor devices for the 7 nm node and beyond. A key point in the successful introduction of EUV lithography in high volume manufacture (HVM) is the effective EUV dose utilization while simultaneously realizing ultra-high resolution and low line edge roughness (LER). Here we show EUV resist sensitivity improvement with the use of a photosensitized chemically amplified resist PSCARTM system. The evaluation of this new chemically amplified resist (CAR) as performed using EUV interference lithography (EUV-IL) is described and the fundamentals are discussed.

  1. Photo-CIDNP of Photosyntheitc Reaction Centers

    SciTech Connect

    Ann. E. McDermott

    2005-10-22

    Studies of Photochemically Induced Dynamic Nuclear Polarization in Photosynthetic Bacterial Reaction Centers: Wavelength and Time Dependence Solid-state NMR spectra of quinone-reduced photosynthetic bacterial reaction centers (RCs) and chromatophores exhibit certain strongly enhanced lines under illumination, a result of photochemically induced dynamic nuclear polarization (photo-CIDNP). This technique offers a new method to investigate photosynthetic electronic transactions while retaining the NMR advantages of narrow linewidths and site-specific resolution. Pulsed laser illumination at 532 nm was used as the basis for time resolved photo-CIDNP experiments, a technique not previously published for solid-state photosynthetic systems. These measurements offer insight about the origin of the polarization effects.

  2. A kinetics investigation of several reactions involving chlorine containing compounds

    NASA Technical Reports Server (NTRS)

    Davis, D. D.

    1978-01-01

    The technique of flash photolysis-resonance fluorescence was utilized to study nine reactions of stratospheric importance. The tropospheric degradation reactions of seven halogenated hydrocarbons were studied to assess their possible influx into the stratosphere. There are reactions of either Cl, OH, or O(3P) species with hydrogenated species, O3 or chlorinated compounds. Apart from the kinetic measurements, the quantum yield for the production of O(1D) from O3 in the crucial wavelength region of 293 to 316.5 nm was studied by utilizing a narrow wavelength laser as the photolysis source. The product formation was monitored by measuring the fluorescence of NO2 formed through O(1D) reaction with N2O followed by NO reaction with O3 to give NO2.

  3. Catalysis in reaction networks.

    PubMed

    Gopalkrishnan, Manoj

    2011-12-01

    We define catalytic networks as chemical reaction networks with an essentially catalytic reaction pathway: one which is "on" in the presence of certain catalysts and "off" in their absence. We show that examples of catalytic networks include synthetic DNA molecular circuits that have been shown to perform signal amplification and molecular logic. Recall that a critical siphon is a subset of the species in a chemical reaction network whose absence is forward invariant and stoichiometrically compatible with a positive point. Our main theorem is that all weakly-reversible networks with critical siphons are catalytic. Consequently, we obtain new proofs for the persistence of atomic event-systems of Adleman et al., and normal networks of Gnacadja. We define autocatalytic networks, and conjecture that a weakly-reversible reaction network has critical siphons if and only if it is autocatalytic. PMID:21503834

  4. Chemisorption And Precipitation Reactions

    EPA Science Inventory

    The transport and bioavailability of chemical components within soils is, in part, controlled by partitioning between solids and solution. General terms used to describe these partitioning reactions include chemisorption and precipitation. Chemisorption is inclusive of the suit...

  5. An Illuminating Reaction.

    ERIC Educational Resources Information Center

    Matthews, Catherine E.

    1996-01-01

    Describes the use of carbide lights as an excellent mechanism for introducing or reviewing many basic chemistry concepts including elements and compounds, endothermic and exothermic reactions, physical and chemical changes, and balancing chemical equations. (JRH)

  6. Reactor for exothermic reactions

    DOEpatents

    Smith, L.A. Jr.; Hearn, D.; Jones, E.M. Jr.

    1993-03-02

    A liquid phase process is described for oligomerization of C[sub 4] and C[sub 5] isoolefins or the etherification thereof with C[sub 1] to C[sub 6] alcohols wherein the reactants are contacted in a reactor with a fixed bed acid cation exchange resin catalyst at an LHSV of 5 to 20, pressure of 0 to 400 psig and temperature of 120 to 300 F. Wherein the improvement is the operation of the reactor at a pressure to maintain the reaction mixture at its boiling point whereby at least a portion but less than all of the reaction mixture is vaporized. By operating at the boiling point and allowing a portion of the reaction mixture to vaporize, the exothermic heat of reaction is dissipated by the formation of more boil up and the temperature in the reactor is controlled.

  7. Iodine Clock Reaction.

    ERIC Educational Resources Information Center

    Mitchell, Richard S.

    1996-01-01

    Describes a combination of solutions that can be used in the study of kinetics using the iodine clock reaction. The combination slows down degradation of the prepared solutions and can be used successfully for several weeks. (JRH)

  8. Untoward penicillin reactions

    PubMed Central

    Guthe, T.; Idsöe, O.; Willcox, R. R.

    1958-01-01

    The literature on untoward reactions following the administration of penicillin is reviewed. These reactions, including a certain number of deaths which have been reported, are of particular interest to health administrations and to WHO in view of the large-scale programmes for controlling the treponematoses which are now under way—programmes affecting millions of people in many parts of the world. The most serious problems are anaphylactic sensitivity phenomena and superinfection or cross-infection with penicillin-resistant organisms, and the reactions involved range in intensity from the mildest to the fatal; the incidence of the latter is estimated at 0.1-0.3 per million injections. The authors point out that with increasing use of penicillin, more persons are likely to become sensitized and the number of reactions can therefore be expected to rise. The best prevention against such an increase is the restriction of the unnecessary use of penicillin. PMID:13596877

  9. Adverse reactions to sulfites

    PubMed Central

    Yang, William H.; Purchase, Emerson C.R.

    1985-01-01

    Sulfites are widely used as preservatives in the food and pharmaceutical industries. In the United States more than 250 cases of sulfite-related adverse reactions, including anaphylactic shock, asthmatic attacks, urticaria and angioedema, nausea, abdominal pain and diarrhea, seizures and death, have been reported, including 6 deaths allegedly associated with restaurant food containing sulfites. In Canada 10 sulfite-related adverse reactions have been documented, and 1 death suspected to be sulfite-related has occurred. The exact mechanism of sulfite-induced reactions is unknown. Practising physicians should be aware of the clinical manifestations of sulfite-related adverse reactions as well as which foods and pharmaceuticals contain sulfites. Cases should be reported to health officials and proper advice given to the victims to prevent further exposure to sulfites. The food industry, including beer and wine manufacturers, and the pharmaceutical industry should consider using alternative preservatives. In the interim, they should list any sulfites in their products. PMID:4052897

  10. Reactor for exothermic reactions

    DOEpatents

    Smith, Jr., Lawrence A.; Hearn, Dennis; Jones, Jr., Edward M.

    1993-01-01

    A liquid phase process for oligomerization of C.sub.4 and C.sub.5 isoolefins or the etherification thereof with C.sub.1 to C.sub.6 alcohols wherein the reactants are contacted in a reactor with a fixed bed acid cation exchange resin catalyst at an LHSV of 5 to 20, pressure of 0 to 400 psig and temperature of 120.degree. to 300.degree. F. Wherein the improvement is the operation of the reactor at a pressure to maintain the reaction mixture at its boiling point whereby at least a portion but less than all of the reaction mixture is vaporized. By operating at the boiling point and allowing a portion of the reaction mixture to vaporize, the exothermic heat of reaction is dissipated by the formation of more boil up and the temperature in the reactor is controlled.

  11. Autocatalysis in reaction networks.

    PubMed

    Deshpande, Abhishek; Gopalkrishnan, Manoj

    2014-10-01

    The persistence conjecture is a long-standing open problem in chemical reaction network theory. It concerns the behavior of solutions to coupled ODE systems that arise from applying mass-action kinetics to a network of chemical reactions. The idea is that if all reactions are reversible in a weak sense, then no species can go extinct. A notion that has been found useful in thinking about persistence is that of "critical siphon." We explore the combinatorics of critical siphons, with a view toward the persistence conjecture. We introduce the notions of "drainable" and "self-replicable" (or autocatalytic) siphons. We show that: Every minimal critical siphon is either drainable or self-replicable; reaction networks without drainable siphons are persistent; and nonautocatalytic weakly reversible networks are persistent. Our results clarify that the difficulties in proving the persistence conjecture are essentially due to competition between drainable and self-replicable siphons. PMID:25245394

  12. Oxygen evolution reaction catalysis

    DOEpatents

    Haber, Joel A.; Jin, Jian; Xiang, Chengxiang; Gregoire, John M.; Jones, Ryan J.; Guevarra, Dan W.; Shinde, Aniketa A.

    2016-09-06

    An Oxygen Evolution Reaction (OER) catalyst includes a metal oxide that includes oxygen, cerium, and one or more second metals. In some instances, the cerium is 10 to 80 molar % of the metals in the metal oxide and/or the catalyst includes two or more second metals. The OER catalyst can be included in or on an electrode. The electrode can be arranged in an oxygen evolution system such that the Oxygen Evolution Reaction occurs at the electrode.

  13. Jets in hadronic reactions

    SciTech Connect

    Paige, F.E.

    1983-01-01

    Recent experimental data on the properties of jets in hadronic reactions are reviewed and compared with theoretical expectations. Jets are clearly established as the dominant process for high E/sub T/ events in hadronic reactions. The cross section and the other properties of these events are in qualitative and even semiquantitative agreement with expectations based on perturbative QCD. However, we can not yet make precise tests of QCD, primarily because there are substantial uncertainties in the theoretical calculations. 45 references. (WHK)

  14. 946 nm Diode Pumped Laser Produces 100mJ

    NASA Technical Reports Server (NTRS)

    Axenson, Theresa J.; Barnes, Norman P.; Reichle, Donald J., Jr.

    2000-01-01

    An innovative approach to obtaining high energy at 946 nm has yielded 101 mJ of laser energy with an optical-to-optical slope efficiency of 24.5%. A single gain module resonator was evaluated, yielding a maximum output energy of 50 mJ. In order to obtain higher energy a second gain module was incorporated into the resonator. This innovative approach produced un-surprised output energy of 101 mJ. This is of utmost importance since it demonstrates that the laser output energy scales directly with the number of gain modules. Therefore, higher energies can be realized by simply increasing the number of gain modules within the laser oscillator. The laser resonator incorporates two gain modules into a folded "M-shaped" resonator, allowing a quadruple pass gain within each rod. Each of these modules consists of a diode (stack of 30 microlensed 100 Watt diode array bars, each with its own fiber lens) end-pumping a Nd:YAG laser rod. The diode output is collected by a lens duct, which focuses the energy into a 2 mm diameter flat to flat octagonal pump area of the laser crystal. Special coatings have been developed to mitigate energy storage problems, including parasitic lasing and amplified spontaneous emission (ASE), and encourage the resonator to operate at the lower gain transition at 946 nm.

  15. Fabrication of 70nm split ring resonators by nanoimprint lithography

    NASA Astrophysics Data System (ADS)

    Sharp, Graham J.; Khokhar, Ali Z.; Johnson, Nigel P.

    2012-05-01

    We report on the fabrication of 70 nm wide, high resolution rectangular U-shaped split ring resonators (SRRs) using nanoimprint lithography (NIL). The fabrication method for the nanoimprint stamp does not require dry etching. The stamp is used to pattern SRRs in a thin PMMA layer followed by metal deposition and lift-off. Nanoimprinting in this way allows high resolution patterns with a minimum feature size of 20 nm. This fabrication technique yields a much higher throughput than conventional e-beam lithography and each stamp can be used numerous times to imprint patterns. Reflectance measurements of fabricated aluminium SRRs on silicon substrates show a so-called an LC resonance peak in the visible spectrum under transverse electric polarisation. Fabricating the SRRs by NIL rather than electron beam lithography allows them to be scaled to smaller dimensions without any significant loss in resolution, partly because pattern expansion caused by backscattered electrons and the proximity effect are not present with NIL. This in turn helps to shift the magnetic response to short wavelengths while still retaining a distinct LC peak.

  16. Discrimination of liver malignancies with 1064 nm dispersive Raman spectroscopy.

    PubMed

    Pence, Isaac J; Patil, Chetan A; Lieber, Chad A; Mahadevan-Jansen, Anita

    2015-08-01

    Raman spectroscopy has been widely demonstrated for tissue characterization and disease discrimination, however current implementations with either 785 or 830 nm near-infrared (NIR) excitation have been ineffectual in tissues with intense autofluorescence such as the liver. Here we report the use of a dispersive 1064 nm Raman system using a low-noise Indium-Gallium-Arsenide (InGaAs) array to discriminate highly autofluorescent bulk tissue ex vivo specimens from healthy liver, adenocarcinoma, and hepatocellular carcinoma (N = 5 per group). The resulting spectra have been combined with a multivariate discrimination algorithm, sparse multinomial logistic regression (SMLR), to predict class membership of healthy and diseased tissues, and spectral bands selected for robust classification have been extracted. A quantitative metric called feature importance is defined based on classification outputs and is used to guide the association of spectral features with biological indicators of healthy and diseased liver tissue. Spectral bands with high feature importance for healthy and liver tumor specimens include retinol, heme, biliverdin, or quinones (1595 cm(-1)); lactic acid (838 cm(-1)); collagen (873 cm(-1)); and nucleic acids (1485 cm(-1)). Classification performance in both binary (normal versus tumor, 100% sensitivity and 89% specificity) and three-group cases (classification accuracy: normal 89%, adenocarcinoma 74%, hepatocellular carcinoma 64%) indicates the potential for accurately separating healthy and cancerous tissues and suggests implications for utilizing Raman techniques during surgical guidance in liver resection. PMID:26309739

  17. Spin-on organic hardmask materials in 70nm devices

    NASA Astrophysics Data System (ADS)

    Oh, Chang-Il; Uh, Dong-Seon; Kim, Do-Hyeon; Lee, Jin-Kuk; Yun, Hui-Chan; Nam, Irina; Kim, Min-Soo; Yoon, Kyong-Ho; Hyung, Kyung-Hee; Tokareva, Nataliya; Cheon, Hwan-Sung; Kim, Jong-Seob; Chang, Tu-Won

    2007-03-01

    In ArF lithography for < 90nm L/S, amorphous carbon layer (ACL) deposition becomes inevitable process because thin ArF resist itself can not provide suitable etch selectivity to sub-layers. One of the problems of ACL hardmask is surface particles which are more problematic in mass production. Limited capacity, high cost-of-ownership, and low process efficiency also make ACL hardmask a dilemma which can not be ignored by device makers. One of the answers to these problems is using a spin-on organic hardmask material instead of ACL hardmask. Therefore, several processes including bi-layer resist process (BLR), tri-layer resist process (TLR), and multi-layer resist process (MLR) have been investigated. In this paper, we have described spin-on organic hardmask materials applicable to 70nm memory devices. Applications to tri-layer resist process (TLR) were investigated in terms of photo property, etch property and process compatibility. Based on the test results described in this paper, our spin-on hardmask materials are expected to be used in mass production.

  18. FIB direct fabrication of sub-10 nm synthetic nanopores

    NASA Astrophysics Data System (ADS)

    Gierak, Jacques; Madouri, Ali; Bourhis, Eric; Marzin, Jean-Yves; Oukhaled, Ghani; Bacri, Laurent; Cressiot, Benjamin; Pelta, Juan; Jede, Ralf; Bruchhaus, Lars; Auvray, Loïc; Lpn Team; Mpi-Lambe Team; Raith Team; Msc Team

    2011-03-01

    Nanopores in thin solid state membranes are used as single molecule electronic detectors or sensors. The membrane acts as a dividing wall in an electrolytic cell and draws charged molecules attracted by an electric field through the pore. Among the very few patterning techniques applicable to nanopores, one promising approach is to use a FIB system, which can produce small holes directly at specified locations with customized organization and shape into dielectric membranes. We detail an innovative FIB-based approach and the methodologies developed for sub-10 nm nanopore realization. Our method allows direct fabrication of nanometer-sized pores in relatively large quantities with excellent reproducibility. This approach offers the possibility to further process or to functionalize each pore on the same scale keeping the required nm-scaled positioning and patterning accuracies, for i.e. adding detection marks or local membrane thinning at nanopore site. Then we describe solutions for conditioning surface properties and for integrating such single nanopore devices for translocation experiments. Results involving DNA, proteins, polymers, colloids are presented.

  19. 1060nm 28-Gbps VCSEL developed at Furukawa

    NASA Astrophysics Data System (ADS)

    Suzuki, Toshihito; Funabashi, Masaki; Shimizu, Hitoshi; Nagashima, Kazuya; Kamiya, Shinichi; Kasukawa, Akihiko

    2014-02-01

    This paper presents recent development results of our 28-Gbps VCSELs featured with double intra-cavity structure and a lasing wavelength of 1060 nm. The double intra-cavity realizes very low cavity loss due to undoped semiconductor bottom DBR and dielectric top DBR layers. Compressively strained InGaAs MQW provides high differential gain that contributes to low power consumption and high reliability. Based on our 10-Gbps VCSEL structure, we carefully optimized MQW, selective oxide structure, cavity length, and doping profile in order to achieve high speed operation while maintaining high reliability and other laser performances. The developed VCSELs exhibit modulation 3 dB-bandwidth exceeding 20 GHz and D-factor of 10 GHz/(mA)1/2. Typical threshold current and slope efficiency are 0.5 mA and 0.5 W/A, respectively. The paper also discusses static and dynamic characteristics of VCSELs with various oxide aperture sizes simultaneously fabricated on the same wafer. For a longer transmission distance and better optical coupling to a multimode fiber, optical lateral confinement is precisely controlled to reduce spectral width as well as far-field pattern. Clearly opened eye diagrams are obtained at a bit rate of 28 Gbps. Bit error rate tests are also performed and 28 Gbps error free transmission has been confirmed over 300 meters of multimode-fiber optimized for 1060 nm with a PRBS pattern length of 231-1.

  20. Discrimination of liver malignancies with 1064 nm dispersive Raman spectroscopy

    PubMed Central

    Pence, Isaac J.; Patil, Chetan A.; Lieber, Chad A.; Mahadevan-Jansen, Anita

    2015-01-01

    Raman spectroscopy has been widely demonstrated for tissue characterization and disease discrimination, however current implementations with either 785 or 830 nm near-infrared (NIR) excitation have been ineffectual in tissues with intense autofluorescence such as the liver. Here we report the use of a dispersive 1064 nm Raman system using a low-noise Indium-Gallium-Arsenide (InGaAs) array to discriminate highly autofluorescent bulk tissue ex vivo specimens from healthy liver, adenocarcinoma, and hepatocellular carcinoma (N = 5 per group). The resulting spectra have been combined with a multivariate discrimination algorithm, sparse multinomial logistic regression (SMLR), to predict class membership of healthy and diseased tissues, and spectral bands selected for robust classification have been extracted. A quantitative metric called feature importance is defined based on classification outputs and is used to guide the association of spectral features with biological indicators of healthy and diseased liver tissue. Spectral bands with high feature importance for healthy and liver tumor specimens include retinol, heme, biliverdin, or quinones (1595 cm−1); lactic acid (838 cm−1); collagen (873 cm−1); and nucleic acids (1485 cm−1). Classification performance in both binary (normal versus tumor, 100% sensitivity and 89% specificity) and three-group cases (classification accuracy: normal 89%, adenocarcinoma 74%, hepatocellular carcinoma 64%) indicates the potential for accurately separating healthy and cancerous tissues and suggests implications for utilizing Raman techniques during surgical guidance in liver resection. PMID:26309739

  1. 240 nm UV LEDs for LISA test mass charge control

    NASA Astrophysics Data System (ADS)

    Olatunde, Taiwo; Shelley, Ryan; Chilton, Andrew; Serra, Paul; Ciani, Giacomo; Mueller, Guido; Conklin, John

    2015-05-01

    Test Masses inside the LISA Gravitational Reference Sensor must maintain almost pure geodesic motion for gravitational waves to be successfully detected. LISA requires residual test mass accelerations below 3 fm/s2/√Hz at all frequencies between 0.1 and 3 mHz. One of the well-known noise sources is associated with the charges on the test masses which couple to stray electrical potentials and external electromagnetic fields. LISA Pathfinder will use Hg-discharge lamps emitting mostly around 254 nm to discharge the test masses via photoemission in its 2015/16 flight. A future LISA mission launched around 2030 will likely replace the lamps with newer UV-LEDs. Presented here is a preliminary study of the effectiveness of charge control using latest generation UV-LEDs which produce light at 240 nm with energy above the work function of pure Au. Their lower mass, better power efficiency and small size make them an ideal replacement for Hg lamps.

  2. Evaluation of fluorinated dissolution inhibitors for 157-nm lithography

    NASA Astrophysics Data System (ADS)

    Hamad, Alyssandrea H.; Houlihan, Francis M.; Seger, Larry; Chang, Chun; Ober, Christopher K.

    2003-06-01

    Fluorinated diesters were synthesized and evaluated as dissolution inhibitors (DIs) for 157 nm lithography. The results of dissolution rate measurements, exposure studies, and etching experiments on blends of fluorinated polymers containing these dissolution inhibitors are reported. It was shown that the DIs effectively slow the dissolution rate of the matrix polymer, poly(hexafluorohydroxyisopropyl styrene) (PHFHIPS). Etching studies show that they enhance the plasma etch resistance of poly(methyl methacrylate) using tetrafluoromethane plasma. Addition of the best performing dissolution inhibitor, cyclohexane-1,4-dicarboxylic acid bis-(1-cyclohexyl-2,2,2-trifluoro-1-methyl-ethyl) ester) (FCDE1) to candidate 157 nm photoresist polymers, Duvcor and poly(hexafluorohydroxyisopropyl styrene)-co-poly(t-butyl methacrylate) [pPHFHIPS-co-pt-BMA], improves the imaging behavior of these polymers. Our attempts to elucidate the mechanism of dissolution inhibition for this series of compounds will be discussed. Fourier Transform Infrared (FTIR) studies in conjunction with dissolution rate measurements performed on a series of DI analogues suggest a mechanism based on hydrogen bonding.

  3. Quality metric for accurate overlay control in <20nm nodes

    NASA Astrophysics Data System (ADS)

    Klein, Dana; Amit, Eran; Cohen, Guy; Amir, Nuriel; Har-Zvi, Michael; Huang, Chin-Chou Kevin; Karur-Shanmugam, Ramkumar; Pierson, Bill; Kato, Cindy; Kurita, Hiroyuki

    2013-04-01

    The semiconductor industry is moving toward 20nm nodes and below. As the Overlay (OVL) budget is getting tighter at these advanced nodes, the importance in the accuracy in each nanometer of OVL error is critical. When process owners select OVL targets and methods for their process, they must do it wisely; otherwise the reported OVL could be inaccurate, resulting in yield loss. The same problem can occur when the target sampling map is chosen incorrectly, consisting of asymmetric targets that will cause biased correctable terms and a corrupted wafer. Total measurement uncertainty (TMU) is the main parameter that process owners use when choosing an OVL target per layer. Going towards the 20nm nodes and below, TMU will not be enough for accurate OVL control. KLA-Tencor has introduced a quality score named `Qmerit' for its imaging based OVL (IBO) targets, which is obtained on the-fly for each OVL measurement point in X & Y. This Qmerit score will enable the process owners to select compatible targets which provide accurate OVL values for their process and thereby improve their yield. Together with K-T Analyzer's ability to detect the symmetric targets across the wafer and within the field, the Archer tools will continue to provide an independent, reliable measurement of OVL error into the next advanced nodes, enabling fabs to manufacture devices that meet their tight OVL error budgets.

  4. 650 nm Laser stimulated dating from Side Antique Theatre, Turkey

    NASA Astrophysics Data System (ADS)

    Doğan, M.; Meriç, N.

    2014-03-01

    Samples were taken from the archeological excavation site, which was at the backs of the Side Antique Theatre. Samples were taken from under the base rock in this area. Polymineral fine grains were examined to determine the ages of the sediments. Samples gathered from the Side Antique Theatre were investigated through using the SAR method. Firstly, one part of the samples were evaluated by using conventional IRSL reading head model of (ELSEC-9010) which is infrared (880±80 nm) stimulation source with Schott BG39 filter. The IRSL age dating with feldspar minerals, gives a number of overestimated or underestimated age values as a result. A new reading head was proposed with the following configuration attachments for overestimation of equivalent dose rates. Measurements were done with this newly designed red laser stimulating reading head which works with Elsec 9010 OSL age dating system. SAR measurements were performed by (650±10 nm) red laser light source with two Schott BG3 filters. With usage of the new designed reading head; closer results were obtained in comparision with the Antique Theatre's expected age range. Fading rates were taken into consideration and these corrections were also handled for true age results.

  5. Efficient 750-nm LED-pumped Nd:YAG laser.

    PubMed

    Huang, Kuan-Yan; Su, Cheng-Kuo; Lin, Meng-Wei; Chiu, Yu-Chung; Huang, Yen-Chieh

    2016-05-30

    We report an Nd:YAG laser pumped by light emission diodes (LEDs) at 750 nm. With 1% output coupling from a linear cavity containing a 2-cm long Nd:YAG crystal, the laser generated 37.5 μJ pulse energy at 1064 nm with M2 = 1.1 when pumped by 2.73-mJ LED energy in a 1-ms pulse at a 10 Hz rate. The measured optical and slope efficiencies for this linear-cavity laser are 1.36, and 9%, respectively. With 1 and 5% output couplings from a Z-cavity containing the same laser crystal, the lasers generated 346 and 288 μJ pulse energy with an optical efficiency of 3.4 and 2.8% and slope efficiency of 6.6 and 14%, respectively, for the same 1-ms pump pulse repeating at a 10 Hz rate. At the highest output from the Z-cavity, the measured M2 for the beam is 3.6. PMID:27410125

  6. Pressure Broadening of the Cadmium 326.1 nm Line

    NASA Astrophysics Data System (ADS)

    Roston, G. D.; Helmi, M. S.

    2014-11-01

    The temperature dependence of the Cd line absorption profile at 326.1nm perturbed by inert gases (Xe, Kr, Ar, Ne and He) has been carefully studied over a wide spectral range in both blue and red wings using a high-resolution double-beam spectrometer. The atomic densities of inert gases (Ngas) and cadmium (NCd) was sufficient to study the wing of the Cd line at 326.1nm. The temperature dependence of the studied line profile was analyzed in the framework of the quasi-static theory. The van der Waals coefficient differences (ΔC60 and ΔC61) between the ground X0+ state and the two excited states A30+ and B31 were obtained from the near red wing profile using Kuhn's law. All the results of the well depths with their positions for the ground (X0+), and the excited (31, 30+) were determined. The obtained results are compared with the corresponding theoretical and experimental molecular beam experiments results.

  7. A simultaneous one pot synthesis of two fractal structures via swapping two fractal reaction kinetic states.

    PubMed

    Ghosh, Subrata; Dutta, Mrinal; Ray, Kanad; Fujita, Daisuke; Bandyopadhyay, Anirban

    2016-06-01

    We introduce a new class of fractal reaction kinetics wherein two or more distinct fractal structures are synthesized as parts of a singular cascade reaction in a single chemical beaker. Two examples: sphere ↔ spiral & triangle ↔ square fractals, grow 10(6) orders from a single dendrimer (8 nm) to the visible scale. PMID:27166589

  8. The ultraviolet photodissociation of Cl2O at 235 nm and of HOCl at 235 and 266 nm

    NASA Astrophysics Data System (ADS)

    Tanaka, Yoshiki; Kawasaki, Masahiro; Matsumi, Yutaka; Fujiwara, Hisashi; Ishiwata, Takashi; Rogers, Leon J.; Dixon, Richard N.; Ashfold, Michael N. R.

    1998-07-01

    The primary photochemistry of gas phase dichlorine monoxide (Cl2O) and of hypochlorous acid (HOCl) following excitation at 235 nm has been investigated using photofragment ion imaging to obtain the recoil velocity and angular distributions of the ground (2P3/2) and spin-orbit excited (2P1/2) atomic chlorine products. In the case of Cl2O, both Cl spin-orbit products exhibit angular distributions characterized by an anisotropy parameter, β=1.2±0.2, consistent with previous interpretations of the ultraviolet (UV) absorption spectrum of Cl2O which associate the broad intense absorption feature peaking at λ˜255 nm with excitation to a (bent) dissociative state of 1B2(C2v) symmetry. The recoil velocity distributions of the two Cl spin-orbit products are markedly different. The ground state atoms (which constitute >90% of the total Cl atom yield) are partnered by ClO fragments carrying significantly higher average levels of internal excitation. The slowest Cl atoms are most readily understood in terms of three body fragmentation of Cl2O to its constituent atoms. These findings are rationalized in terms of a model potential energy surface for the 1 1B2 state, which correlates diabatically with ClO(X) radicals together with a spin-orbit excited Cl atom, with efficient radiationless transfer to one (or more) lower energy surfaces at extended Cl-O bond lengths accounting for the dominance of ground state Cl atom fragments. The image of the ground state Cl atoms resulting from photolysis of HOCl at 235 nm is consistent with parent excitation via a transition for which the dipole moment is closely aligned with the Cl-O bond, followed by prompt dissociation (β=1.7±0.2) with the bulk of the excess energy partitioned into product recoil. Such conclusions are consistent with the results of laser induced fluorescence measurements of the OH(X) products resulting from 266 nm photodissociation of HOCl which reveal OH(X) products in both spin-orbit states, exclusively in their

  9. Holistic overlay control for multi-patterning process layers at the 10nm and 7nm nodes

    NASA Astrophysics Data System (ADS)

    Verstappen, Leon; Mos, Evert; Wardenier, Peter; Megens, Henry; Schmitt-Weaver, Emil; Bhattacharyya, Kaustuve; Adam, Omer; Grzela, Grzegorz; van Heijst, Joost; Willems, Lotte; Wildenberg, Jochem; Ignatova, Velislava; Chen, Albert; Elich, Frank; Rajasekharan, Bijoy; Vergaij-Huizer, Lydia; Lewis, Brian; Kea, Marc; Mulkens, Jan

    2016-03-01

    Multi-patterning lithography at the 10-nm and 7-nm nodes is driving the allowed overlay error down to extreme low values. Advanced high order overlay correction schemes are needed to control the process variability. Additionally the increase of the number of split layers results in an exponential increase of metrology complexity of the total overlay and alignment tree. At the same time, the process stack includes more hard-mask steps and becomes more and more complex, with as consequence that the setup and verification of the overlay metrology recipe becomes more critical. All of the above require a holistic approach that addresses total overlay optimization from process design to process setup and control in volume manufacturing. In this paper we will present the holistic overlay control flow designed for 10-nm and 7-nm nodes and illustrate the achievable ultimate overlay performance for a logic and DRAM use case. As figure 1 illustrates we will explain the details of the steps in the holistic flow. Overlay accuracy is the driver for target design and metrology tool optimization like wavelength and polarization. We will show that it is essential to include processing effects like etching and CMP which can result in a physical asymmetry of the bottom grating of diffraction based overlay targets. We will introduce a new method to create a reference overlay map, based on metrology data using multiple wavelengths and polarization settings. A similar approach is developed for the wafer alignment step. The overlay fingerprint correction using linear or high order correction per exposure (CPE) has a large amount of parameters. It is critical to balance the metrology noise with the ultimate correction model and the related metrology sampling scheme. Similar approach is needed for the wafer align step. Both for overlay control as well as alignment we have developed methods which include efficient use of metrology time, available for an in the litho-cluster integrated

  10. Enzyme Reactions in Nanoporous, Picoliter Volume Containers

    PubMed Central

    Siuti, Piro; Retterer, Scott T.; Choi, Chang-Kyoung; Doktycz, Mitchel J.

    2012-01-01

    Advancements in nanoscale fabrication allow creation of small volume reaction containers that can facilitate the screening and characterization of enzymes. A porous, ~19 pL volume vessel has been used in this work to carry out enzyme reactions under varying substrate concentrations. Assessment of small molecule and Green Fluorescent Protein diffusion from the vessels indicates that pore sizes on order of 10 nm can be obtained, allowing capture of proteins and diffusive exchange of small molecules. Glucose oxidase and horseradish peroxidase can be contained in these structures and diffusively fed with a solution containing glucose and the fluorogenic substrate Amplex Red™ through the engineered nanoscale pore structure. Fluorescent microscopy was used to monitor the reaction, which was carried out under microfluidic control. Kinetic characteristics of the enzyme (Km and Vmax) were evaluated and compared with results from conventional scale reactions. These picoliter, nanoporous containers can facilitate quick determination of enzyme kinetics in microfluidic systems without the requirement of surface tethering and can be used for applications in drug discovery, clinical diagnostics and high-throughput screening. PMID:22148720

  11. Next generation 8xx nm laser bars and single emitters

    NASA Astrophysics Data System (ADS)

    Strauss, Uwe; Müller, Martin; Swietlik, Tomasz; Fehse, Robin; Lauer, Christian; Grönninger, Günther; König, Harald; Keidler, Markus; Fillardet, Thierry; Kohl, Andreas; Stoiber, Michael; Scholl, Iris; Biesenbach, Jens; Baeumler, Martina; Konstanzer, Helmer

    2011-03-01

    Semiconductor lasers with emission in the range 790 - 880 nm are in use for a variety of application resulting in different laser designs to fulfill requirements in output power, operation temperature and lifetimes. The output power is limited by self heating and catastrophic optical mirror damage at the laser facet (COMD). Now we present data on bars fabricated with our new facet technology, which enables us to double the maximum facet load. We present q-cw laser bar with 80% fill factor with increased power level to 350W in long term operation at 200μs and 100Hz. The COMD limit of the bar is as high as 680W. Using Quantel's optimized packaging stacks with 11 bars of 5mm widths are tested at up to 120A resulting over 66% power conversion efficiency at 1600W output power. Laser bars for continuous wave operation like 50% fill factor bars had an COMD limit of approx. 250W with conventional facet technology, the value is equivalent to 10W per 200μm emitter (conditions: 200μs). The new facet technology pushes the facet stability to 24W/emitter. The new process and an improved design enable us to shift continuous wave operation at 808nm from 100W to 150W/bar with lifetimes of several thousand hours at 30°C using DILAS mounting technology. Higher power is possible depending on lifetime requirements. The power conversion efficiency of the improved devices is as high as 62% at 200W cw. The next limitation of 8xxnm lasers is high temperature operation: Values of 60-80°C are common for consumer applications of single emitters. Therefore Osram developed a new epitaxial design which reduced the generation of bulk defects. The corresponding Osram single emitters operate at junction temperatures up to 95°C, a value which corresponds to 80°C heat sink temperature for lasers soldered on C-mount or 65°C case temperature for lasers mounted in TO can. Current densities of the single emitter broad area lasers are as high as 1.4kA/cm2 at 850nm emission wavelength.

  12. [Cutaneous adverse drug reactions].

    PubMed

    Lebrun-Vignes, B; Valeyrie-Allanore, L

    2015-04-01

    Cutaneous adverse drug reactions (CADR) represent a heterogeneous field including various clinical patterns without specific features suggesting drug causality. Exanthematous eruptions, urticaria and vasculitis are the most common forms of CADR. Fixed eruption is uncommon in western countries. Serious reactions (fatal outcome, sequelae) represent 2% of CADR: bullous reactions (Stevens-Johnson syndrome, toxic epidermal necrolysis), DRESS (drug reaction with eosinophilia and systemic symptoms or drug-induced hypersensitivity syndrome) and acute generalized exanthematous pustulosis (AGEP). These forms must be quickly diagnosed to guide their management. The main risk factors are immunosuppression, autoimmunity and some HLA alleles in bullous reactions and DRESS. Most systemic drugs may induce cutaneous adverse reactions, especially antibiotics, anticonvulsivants, antineoplastic drugs, non-steroidal anti-inflammatory drugs, allopurinol and contrast media. Pathogenesis includes immediate or delayed immunologic mechanism, usually not related to dose, and pharmacologic/toxic mechanism, commonly dose-dependent or time-dependent. In case of immunologic mechanism, allergologic exploration is possible to clarify drug causality, with a variable sensitivity according to the drug and to the CADR type. It includes epicutaneous patch testing, prick test and intradermal test. However, no in vivo or in vitro test can confirm the drug causality. To determine the cause of the eruption, a logical approach based on clinical characteristics, chronologic factors and elimination of differential diagnosis is required, completed with a literature search. A reporting to pharmacovigilance network is essential in case of a serious CADR whatever the suspected drug and in any case if the involved drug is a newly marketed one or unusually related to cutaneous reactions. PMID:25458866

  13. Efficient generation of 1096 nm and 1572 nm by simultaneous stimulated Raman scattering and optical parametric oscillation in one KTiOPO4 crystal

    NASA Astrophysics Data System (ADS)

    Huang, H. T.; He, J. L.; Liu, S. D.; Yang, J. F.; Zhang, B. T.; Liu, F. Q.

    2011-04-01

    The simultaneous stimulated Raman scattering (SRS) and optical parametric oscillation (OPO) for the 1064 nm radiation were realized in one KTP crystal for the first time. At an incident diode laser power of 8.6 W, the maximum average output powers at 1096 nm and 1572 nm were 1.1 W and 0.36 W, respectively. The conversion efficiency to Stokes with respect to the incident diode power was as high as 12.8%. The corresponding minimum pulse widths at 1096 nm and 1572 nm were 2.8 and 1.1 ns, respectively.

  14. Dosimetric analysis for low-level laser therapy (LLLT) of the human inner ear at 593 nm and 633 nm

    NASA Astrophysics Data System (ADS)

    Beyer, Wolfgang; Baumgartner, Reinhold; Tauber, Stefan

    1998-12-01

    The administration of low-level-laserlight for irradiation of the inner ear could represented a new therapeutic model for complex diseases of the inner ear. However, successful therapy requires a well-defined light dosimetry based on a dosimetric analysis of the human cochlea that represents a complex anatomy. The light distribution inside the cochlear windings, produced by an irradiation of the tympanic membrane, was quantitatively measured ex vivo for HeNe laser wavelengths of 593 nm and 633 nm. To obtain the space irradiance within an intact cochlea a correction factor of about 6 has been determined by Monte Carlo calculations. It follows from 3 contributions, first the backscattering of light in the bony parts removed during the preparation procedure of the specimen, second the change of index of refraction from the bony parts to air and third some geometrical factors due to the angular distribution of the radiation. The transmission of light across the tympanic cavity and the promontory depends strongly on the wavelength. Due to the observed spatial intensity variations of a factor 10 and more inside the cochlear windings the optimum external light dose has to be chosen with regard to the tonotopy of the ear.

  15. Time-resolved spectroscopy of nucleic acid systems using synchrotron radiation from 230 nm to 354 nm

    NASA Astrophysics Data System (ADS)

    Daniels, Malcolm; Ballini, Jean-Pierre; Vigny, Paul

    1992-07-01

    The excited states of nucleic acids are complex, both at the individual chromophore level and because of the effect of stacking interactions on the electronic states. Considerable progress has been made recently by studying the lifetimes of the stacked states and by utilizing the technique of time-resolved spectroscopy. Experimental results obtained using the ACO synchrotron at LURE, Orsay, will be presented. Resolution of the decay data gives a model-based estimate of the number of emitting species and their lifetimes, and this information is then used to deconvolate experimental time-windowed spectra (time-delayed spectra) to give true time-resolved spectra. It is a unique feature of the synchrotron, compared with the laser, that the combination of delayed detection (photon counting) with the continuous wavelength distribution of the synchrotron allows the acquisition of excitation spectra by uninterrupted repetitive scanning over a wide range of UV exciting wavelengths, in the present work from 230 nm to 354 nm. Such time-delayed excitation spectra can also be deconvoluted into components corresponding to the various time-resolved emission spectra. In this way we are able to demonstrate for the first time that ground state stacking interactions are directly responsible for excimer-like emissions. Time-resolved emission spectra and time-resolved excitation spectra will be presented for the dinucleoside phosphate d(CG) and the synthetic alternating polynucleotide poly d(GC), a `B-type' DNA structure.

  16. Shock induced reaction of Ni/Al nanopowder mixture.

    PubMed

    Meng, C M; Wei, J J; Chen, Q Y

    2012-11-01

    Nanopowder Ni/Al mixture (mixed in Al:Ni = 2:1 stoichiometry) was shock compressed by employing single and two-stage light gas gun. The particle size of Al and Ni are 100-200 nm and 50-70 nm respectively, morphologies of Al and Ni are sphere like either. Recovered product was characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD) analysis. According to the XRD spectrum, the mixed powder undergo complete reaction under shock compression, reaction product consist of Ni2Al3, NiAl and corundum structure Al2O3 compound. Grain size of Ni-Al compound is less than 100 nm. With the shock pressure increasing, the ratio of Ni2Al3 decreased obviously. The corundum crystal size is 400-500 nm according to the SEM observation. The results of shock recovery experiments and analysis show that the threshold pressure for reaction of nano size powder Ni/Al mixture is much less than that of micro size powder. PMID:23421276

  17. Fluorescence microscopy with 6 nm resolution on DNA origami.

    PubMed

    Raab, Mario; Schmied, Jürgen J; Jusuk, Ija; Forthmann, Carsten; Tinnefeld, Philip

    2014-08-25

    Resolution of emerging superresolution microscopy is commonly characterized by the width of a point-spread-function or by the localization accuracy of single molecules. In contrast, resolution is defined as the ability to separate two objects. Recently, DNA origamis have been proven as valuable scaffold for self-assembled nanorulers in superresolution microscopy. Here, we use DNA origami nanorulers to overcome the discrepancy of localizing single objects and separating two objects by resolving two docking sites at distances of 18, 12, and 6 nm by using the superresolution technique DNA PAINT(point accumulation for imaging in nanoscale topography). For the smallest distances, we reveal the influence of localization noise on the yield of resolvable structures that we rationalize by Monte Carlo simulations. PMID:24895173

  18. Quantity change in collagen following 830-nm diode laser welding

    NASA Astrophysics Data System (ADS)

    Tang, Jing; O'Callaghan, David; Rouy, Simone; Godlewski, Guilhem; Prudhomme, Michel

    1996-12-01

    The actual mechanism for production of laser welding of tissue is presently unknown, but collagen plays an important role is tissue welded after laser irradiance. The quantity change in collagen extracted from the abdominal aorta of Wistar rats after tissue welding using an 830 nm diode laser was investigated. The collagen contents following repeated pepsin digestion after acetic acid extraction were determined with Sircol collagen assay. Compared with untreated aorta, the collagen content of the treated vessel was obvious decreased immediately after laser irradiation and following an initial increase on day 3, there was a peak at day 10. The results suggest that a part of collagen molecules is denatured by the heat of laser. There is an effect of stimulating collagen synthesis after laser welding with parameters used in this study.

  19. Pollution Prevention Opportunity Assessment for the SNL/NM cafeterias.

    SciTech Connect

    McCord, Samuel Adam

    2005-12-01

    This Pollution Prevention Opportunity Assessment (PPOA) was conducted for the two Sandia National Laboratories/New Mexico cafeteria facilities between May and August 2005. The primary purpose of this PPOA is to assess waste and resource reduction opportunities and issue Pollution Prevention (P2) recommendations for Sandia's food service facilities. This PPOA contains recommendations for energy, water and resource reduction, as well as material substitution based upon environmentally preferable purchasing. Division 3000 has requested the PPOA report as part of the Division's compliance effort to implement the Environmental Management System (EMS) per DOE Order 450.1. This report contains a summary of the information collected and analyses performed with recommended options for implementation. The SNL/NM P2 Group will work with Division 3000 and the respective cafeteria facilities to implement these options.

  20. Megasonic cleaning: possible solutions for 22nm node and beyond

    NASA Astrophysics Data System (ADS)

    Shende, Hrishi; Singh, Sherjang; Baugh, James; Mann, Raunak; Dietze, Uwe; Dress, Peter

    2011-11-01

    Megasonic energy transfer to the photomask surface is indirectly controlled by process parameters that provide an effective handle to physical force distribution on the photomask surface. A better understanding of the influence of these parameters on the physical force distribution and their effect on pattern damage of fragile mask features can help optimize megasonic energy transfer as well as assist in extending this cleaning technology beyond the 22nm node. In this paper we have specifically studied the effect of higher megasonic frequencies (3 & 4MHz) and media gasification on pattern damage; the effect of cleaning chemistry, media volume flow rate, process time, and nozzle distance to the mask surface during the dispense is also discussed. Megasonic energy characterization is performed by measuring the acoustic energy as well as cavitation created by megasonic energy through sonoluminescence measurements.

  1. Discrete plasticity in sub-10-nm-sized gold crystals.

    PubMed

    Zheng, He; Cao, Ajing; Weinberger, Christopher R; Huang, Jian Yu; Du, Kui; Wang, Jianbo; Ma, Yanyun; Xia, Younan; Mao, Scott X

    2010-01-01

    Although deformation processes in submicron-sized metallic crystals are well documented, the direct observation of deformation mechanisms in crystals with dimensions below the sub-10-nm range is currently lacking. Here, through in situ high-resolution transmission electron microscopy (HRTEM) observations, we show that (1) in sharp contrast to what happens in bulk materials, in which plasticity is mediated by dislocation emission from Frank-Read sources and multiplication, partial dislocations emitted from free surfaces dominate the deformation of gold (Au) nanocrystals; (2) the crystallographic orientation (Schmid factor) is not the only factor in determining the deformation mechanism of nanometre-sized Au; and (3) the Au nanocrystal exhibits a phase transformation from a face-centered cubic to a body-centered tetragonal structure after failure. These findings provide direct experimental evidence for the vast amount of theoretical modelling on the deformation mechanisms of nanomaterials that have appeared in recent years. PMID:21266994

  2. Photolithography reaches 6 nm half-pitch using EUV light

    NASA Astrophysics Data System (ADS)

    Fan, Daniel; Ekinci, Yasin

    2016-03-01

    EUV 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. 6 nm half-pitch patterns were achieved using these masks marking a new record resolution in photolithography.

  3. Wind Measurements with a 355 nm Molecular Doppler Lidar

    NASA Technical Reports Server (NTRS)

    Gentry, Bruce M.; Chen, Huailin; Li, Steven X.

    2000-01-01

    A Doppler lidar system based on the molecular double edge technique is described. The system is mounted in a modified van to allow deployment in field operations. The lidar operates with a tripled Nd:YAG laser at 355 nm, a 45cm aperture telescope and a matching azimuth-over-elevation scanner to allow full sky access. Validated atmospheric wind profiles have been measured from 1.8 km to 35 km with a 178 m vertical resolution. The range dependent rms deviation of the horizontal wind speed is 0.4 - 6 m/s. The results of wind speed and direction are in good agreement with balloon sonde wind measurements made simultaneously at the same location.

  4. Total dose responses and reliability issues of 65 nm NMOSFETs

    NASA Astrophysics Data System (ADS)

    Dezhao, Yu; Qiwen, Zheng; Jiangwei, Cui; Hang, Zhou; Xuefeng, Yu; Qi, Guo

    2016-06-01

    In this paper, total dose responses and reliability issues of MOSFETs fabricated by 65 nm CMOS technology were examined. “Radiation-induced narrow channel effect” is observed in a narrow channel device. Similar to total dose responses of NMOSFETs, narrow channel NMOSFEs have larger hot-carrier-induced degradation than wide channel devices. Step Time-Dependent Dielectric Breakdown (TDDB) stresses are applied, and narrow channel devices have higher breakdown voltage than wide channel devices, which agree with “weakest link” theory of TDDB. Experimental results show that linear current, transconductance, saturated drain current and subthreshold swing are superposed degenerated by total dose irradiation and reliability issues, which may result in different lifetime from that considering total dose irradiation reliability issues separately. Project supported by “Light of West China” Program of CAS (No. XBBS201219).

  5. Results of the VISA SASE FEL Experiment at 840 nm

    SciTech Connect

    Murokh, A.

    2004-01-20

    VISA (Visible to Infrared SASE Amplifier) is a high-gain self-amplified spontaneous emission FEL, which achieved saturation at 840 nm within a single-pass 4-m undulator. A gain length shorter than 18 cm has been obtained, yielding the gain of 2 x 10{sup 8} at saturation. The FEL performance, including spectral, angular, and statistical properties of SASE radiation, has been characterized for different electron beam conditions. The results are compared to 3-D SASE FEL theory and start-to-end numerical simulations of the entire injector, transport, and FEL system. Detailed agreement between simulations and experimental results is obtained over the wide range of the electron beam parameters.

  6. Results of the VISA SASE FEL experiment at 840 nm

    NASA Astrophysics Data System (ADS)

    Murokh, A.; Agustsson, R.; Babzien, M.; Ben-Zvi, I.; Bertolini, L.; van Bibber, K.; Carr, R.; Cornacchia, M.; Frigola, P.; Hill, J.; Johnson, E.; Klaisner, L.; Le Sage, G.; Libkind, M.; Malone, R.; Nuhn, H.-D.; Pellegrini, C.; Reiche, S.; Rakowsky, G.; Rosenzweig, J.; Ruland, R.; Skaritka, J.; Toor, A.; Tremaine, A.; Wang, X.; Yakimenko, V.

    2003-07-01

    VISA (Visible to Infrared SASE Amplifier) is a high-gain self-amplified spontaneous emission FEL, which achieved saturation at 840 nm within a single-pass 4-m undulator. A gain length shorter than 18 cm has been obtained, yielding the gain of 2×10 8 at saturation. The FEL performance, including spectral, angular, and statistical properties of SASE radiation, has been characterized for different electron beam conditions. The results are compared to 3-D SASE FEL theory and start-to-end numerical simulations of the entire injector, transport, and FEL system. Detailed agreement between simulations and experimental results is obtained over the wide range of the electron beam parameters.

  7. Search for solar neutrons using NM-64 equipment

    NASA Technical Reports Server (NTRS)

    Martinic, N. J.; Reguerin, A.; Palenque, E.; Wada, M.; Inoue, A.; Takahashi, K.; Taquichiri, M. A.

    1985-01-01

    Two years (1980 to 1982) neutron monitor data from the Chacaltaya (geographic coordinates: N16.32 deg W68. 15 deg; cutoff rigidity: 13.1 GV; altitude: 5,300 m a.s.l.) station has been scanned; the sampling time of the 12NM-64 neutron monitor is 5 min. The nucleonic component increases have been correlated with 66 hard X-, gamma rays satellite data from solar origin, as reported by several groups. Typical neutron monitor time profiles of the events are presented. Chree-analysis was performed discriminating the events according to its solar coordinates. Ground data from solar limb locii are more enhanced at the time of the onset than other geometrically visible flares. Chree histograms of neutron monitor output profiles are also presented from geometrically invisible events from the Chacaltaya station.

  8. Multilayer reticles: advantages and challenges for 28nm chip making

    NASA Astrophysics Data System (ADS)

    Hotzel, Arthur; Seltmann, Rolf; Busch, Jens; Cotte, Eric

    2011-03-01

    Chip manufacturing with multilayer reticles offers the possibility to reduce reticle cost at the expense of scanner throughput, and is therefore an attractive option for small-volume production and test chips. Since 2010, GLOBALFOUNDRIES Fab 1 uses this option for the 28nm IP shuttles and test chips offered to their customers for development and advance testing of their products. This paper discusses the advantages and challenges of this approach and the practical experience gained during implementation. One issue that must be considered is the influence of the small image field and the asymmetric reticle illumination on the lithographic key parameters, namely layer to layer overlay. Theoretical considerations and experimental data concerning the effects of lens distortion, lens heating, and reticle heating on overlay performance are presented, and concepts to address the specific challenges of multilayer reticles for high-end chip production are discussed.

  9. Discrete plasticity in sub-10-nm-sized gold crystals

    PubMed Central

    Zheng, He; Cao, Ajing; Weinberger, Christopher R.; Huang, Jian Yu; Du, Kui; Wang, Jianbo; Ma, Yanyun; Xia, Younan; Mao, Scott X.

    2010-01-01

    Although deformation processes in submicron-sized metallic crystals are well documented, the direct observation of deformation mechanisms in crystals with dimensions below the sub-10-nm range is currently lacking. Here, through in situ high-resolution transmission electron microscopy (HRTEM) observations, we show that (1) in sharp contrast to what happens in bulk materials, in which plasticity is mediated by dislocation emission from Frank-Read sources and multiplication, partial dislocations emitted from free surfaces dominate the deformation of gold (Au) nanocrystals; (2) the crystallographic orientation (Schmid factor) is not the only factor in determining the deformation mechanism of nanometre-sized Au; and (3) the Au nanocrystal exhibits a phase transformation from a face-centered cubic to a body-centered tetragonal structure after failure. These findings provide direct experimental evidence for the vast amount of theoretical modelling on the deformation mechanisms of nanomaterials that have appeared in recent years. PMID:21266994

  10. Fabrication of sub-15 nm aluminum wires by controlled etching

    NASA Astrophysics Data System (ADS)

    Morgan-Wall, T.; Hughes, H. J.; Hartman, N.; McQueen, T. M.; Marković, N.

    2014-04-01

    We describe a method for the fabrication of uniform aluminum nanowires with diameters below 15 nm. Electron beam lithography is used to define narrow wires, which are then etched using a sodium bicarbonate solution, while their resistance is simultaneously measured in-situ. The etching process can be stopped when the desired resistance is reached, and can be restarted at a later time. The resulting nanowires show a superconducting transition as a function of temperature and magnetic field that is consistent with their smaller diameter. The width of the transition is similar to that of the lithographically defined wires, indicating that the etching process is uniform and that the wires are undamaged. This technique allows for precise control over the normal state resistance and can be used to create a variety of aluminum nanodevices.

  11. Initiation Identification in Fused Silica 355-nm Optics

    SciTech Connect

    Wall, M; Plitzko, J; Fluss, M J

    2002-01-04

    Thermo-mechanical surface damage initiation and growth in fused-silica 3{omega} (355nm) optics are important performance and cost issues for high-power lasers (fluences of 4-14 J/cm{sup 2}) in the few ns pulse length regime. We are working to characterize and identify the extrinsic origins of damage initiation; impurities, particulates, and manufacturing defects. We have performed a materials characterization survey approach using transmission electron microscopy to identify the chemistry and morphology of particles, and structural defects. TEM offers high chemical or elemental specificity and small analytical spot size yielding complementary materials characterization data and powerful clues to manufacturing improvements. We will report on our characterization of the near surface of one commercially manufactures fused silica optic, where the results indicate both the efficacy and potential value of this approach.

  12. Achieving 50 nm lateral-resolution quantitative EDX SEM

    NASA Astrophysics Data System (ADS)

    Pimentel, G.; Lozano-Perez, S.

    2015-10-01

    Low Voltage Scanning Electron Microscopy (LV-SEM) has become a very promising approach to perform Energy Dispersive X-ray (EDX) chemical mapping with high- lateral resolution [1]. Using voltages as low as 1.5keV, sub-10nm resolutions can be achieved. In this work, we try to take advantage of the small interaction volume in order to simplify the otherwise more complex SEM quantitative methodology. This way, phenomena such as absorption and fluorescence can be ignored and, effectively treat the quantification as with the Transmission Electron Microscopy (TEM)-based Cliff-Lorimer method. Experimental k- factors have been obtained from a series of standards and used to quantify complex oxide phases in steels.

  13. High-index optical materials for 193nm immersion lithography

    NASA Astrophysics Data System (ADS)

    Burnett, John H.; Kaplan, Simon G.; Shirley, Eric L.; Horowitz, Deane; Clauss, Wilfried; Grenville, Andrew; Van Peski, Chris

    2006-03-01

    We report on our comprehensive survey of high-index UV optical materials that may enable extension of immersion lithography beyond a numerical aperture of 1.45. Band edge, refractive index, and intrinsic birefringence (IBR) at 193 nm determine basic viability. Our measurements of these properties have reduced the list of potential candidates to: ceramic spinel, lutetium aluminum garnet, and a class of germanium garnets. We discuss our measurements of the intrinsic properties of these materials and assess the present status of their material quality relative to requirements. Ceramic spinel has no significant IBR, but transmission and scatter for the best samples remain at least two orders of magnitude from specifications. Improving these would require a major development effort. Presently available lutetium aluminum garnet has material quality much closer to the specifications. However, the IBR is about three times the required value. The germanium garnets offer the possibility of a lower IBR, but a suitable candidate material has yet to be established.

  14. NM-Scale Anatomy of an Entire Stardust Carrot Track

    NASA Technical Reports Server (NTRS)

    Nakamura-Messenger, K.; Keller, L. P.; Clemett, S. J.; Messenger, S.

    2009-01-01

    Comet Wild-2 samples collected by NASA s Stardust mission are extremely complex, heterogeneous, and have experienced wide ranges of alteration during the capture process. There are two major types of track morphologies: "carrot" and "bulbous," that reflect different structural/compositional properties of the impactors. Carrot type tracks are typically produced by compact or single mineral grains which survive essentially intact as a single large terminal particle. Bulbous tracks are likely produced by fine-grained or organic-rich impactors [1]. Owing to their challenging nature and especially high value of Stardust samples, we have invested considerable effort in developing both sample preparation and analytical techniques tailored for Stardust sample analyses. Our report focuses on our systematic disassembly and coordinated analysis of Stardust carrot track #112 from the mm to nm-scale.

  15. Preparation and size control of sub-100 nm pure nanodrugs.

    PubMed

    Zhang, Jinfeng; Li, Yanan; An, Fei-Fei; Zhang, Xiaohong; Chen, Xianfeng; Lee, Chun-Sing

    2015-01-14

    Pure nanodrugs (PNDs), nanoparticles consisting entirely of drug molecules, have been considered as promising candidates for next-generation nanodrugs. However, the traditional preparation method via reprecipitation faces critical challenges including low production rates, relatively large particle sizes, and batch-to-batch variations. Here, for the first time, we successfully developed a novel, versatile, and controllable strategy for preparing PNDs via an anodized aluminum oxide (AAO) template-assisted method. With this approach, we prepared PNDs of an anticancer drug (VM-26) with precisely controlled sizes reaching the sub-20 nm range. This template-assisted approach has much higher feasibility for mass production comparing to the conventional reprecipitation method and is beneficial for future clinical translation. The present method is further demonstrated to be easily applicable for a wide range of hydrophobic biomolecules without the need of custom molecular modifications and can be extended for preparing all-in-one nanostructures with different functional agents. PMID:25514014

  16. Characterization of a THz CW spectrometer pumped at 1550 nm

    NASA Astrophysics Data System (ADS)

    Yeo, Woon-Gi; Nahar, Niru K.

    2015-07-01

    We present an evaluation of a cost-effective THz CW spectrometer pumped at 1550 nm wavelengths with a fixed delay line. To study the spectral competence of the spectrometer, transmission data is obtained for various organic and inorganic samples. Spectral comparisons of the samples are presented by using THz time domain spectroscopy and vector network analyzer (VNA). Despite the capability of highly resolved transmission spectroscopy, our current system reveals the uncertainty in interferometric output data for phase analysis. Here, we identify the effect of fringing space of raw output data toward frequency resolution, phase analysis, and data acquisition time. We also propose the proper delay line setup for phase analysis for this type of spectrometers.

  17. Characterization of EUV resists for defectivity at 32nm

    NASA Astrophysics Data System (ADS)

    Montal, Ofir; Dolev, Ido; Rosenzweig, Moshe; Dotan, Kfir; Meshulach, Doron; Adan, Ofer; Levi, Shimon; Cai, Man-Ping; Bencher, Chris; Ngai, Chris S.; Jehoul, Christiane; Van Den Heuvel, Dieter; Hendrickx, Eric

    2011-03-01

    Extreme ultraviolet (EUV) lithography is considered as the leading patterning technology beyond the ArF-based optical lithography, addressing the need for transistor densification to meet Moore's Law. Theoretically, EUV lithography at 13.5nm wavelength meets the resolution requirements for 1xnm technology nodes. However, there are several major challenges in the development of EUV lithography for mass production of advanced CMOS devices. These include the development of high power EUV light sources, EUV optics, EUV masks, EUV resists, overlay accuracy, and metrology and inspection capabilities. In particular, it is necessary to ensure that effective defect control schemes will be made available to reduce the EUV lithography defectivity to acceptable levels. This paper presents a study on the wafer defectivity and characterization of patterned EUV resists, with the objective of providing a quantitative comparison between the defectivity of different resist materials and different stacks. Patterned wafers were printed using the ASML® EUV full-field Alpha-Demo Tool (ADT 0.25 NA) at imec. The EUV resist patterns were 32nm line/spaces. Several advanced resist types were screened experimentally. The different resist types and stacks were inspected using a DUV laser based brightfield inspection tool, followed by a SEM defect review and CD metrology measurements. The patterns were characterized in terms of defect types and defect density. We identified the major defect types and discuss factors that affect the defectivity level and pattern quality, such as resist type, exposure dose and focus. Defect scattering analysis of DUV polarized light at different polarizations was performed, to indicate on the inspection performance trends for a variety of defect types and sizes of the different resists and stacks. The scattering analysis shows that higher defect scattering is induced using polarized light.

  18. Multiple product pathways in photodissociation of nitromethane at 213 nm

    NASA Astrophysics Data System (ADS)

    Sumida, Masataka; Kohge, Yasunori; Yamasaki, Katsuyoshi; Kohguchi, Hiroshi

    2016-02-01

    In this paper, we present a photodissociation dynamics study of nitromethane at 213 nm in the π → π* transition. Resonantly enhanced multiphoton ionization spectroscopy and ion-imaging were applied to measure the internal state distributions and state-resolved scattering distributions of the CH3, NO(X 2Π, A 2Σ+), and O(3PJ) photofragments. The rotationally state-resolved scattering distribution of the CH3 fragment showed two velocity components, of which the slower one decreased the relative intensity as the rotational and vibrational excitations. The translational energy distribution of the faster CH3 fragment indicated the production of the NO2 counter-product in the electronic excited state, wherein 1 2B2 was the most probable. The NO(v = 0) fragment exhibited a bimodal translational energy distribution, whereas the NO(v = 1 and 2) fragment exhibited a single translational energy component with a relatively larger internal energy. The translational energy of a portion of the O(3PJ) photofragment was found to be higher than the one-photon dissociation threshold, indicating the two-photon process involved. The NO(A 2Σ+) fragment, which was detected by ionization spectroscopy via the Rydberg ←A 2Σ+ transition, also required two-photon energy. These experimental data corroborate the existence of competing photodissociation product pathways, CH3 + NO2,CH3 + NO + O,CH3O + NO, and CH3NO + O, following the π → π* transition. The origins of the observed photofragments are discussed in this report along with recent theoretical studies and previous dynamics experiments performed at 193 nm.

  19. Lasing at 300 nm and below: Optical challenges and perspectives

    SciTech Connect

    Garzella, D.; Couprie, M.E. |; Billardon, M.

    1995-12-31

    The FEL experiment in the visible and near UV on the Super ACO storage ring has given, since 1989, important informations on the SRFEL dynamics and, furthermore, a very good beam stability has been achieved. In addition, the operation at 350 nm with this good stability and a long beam lifetime allowed us to perform the first user experiment in biology and to start with a campaign for using the laser as photons source for experiments in other domains, coupling FEL light and the Synchrotron Radiation. For this, FEL starts to be very competitive with respect to the other conventional laser sources, provided that it could oscillate further in the UV, say at 300 nm and below. So, the real challenge is now given by the lasing at shorter wavelengths and, for this, by the optical technology existing nowadays. Since 1992 the efforts have been concentrating to look for every kind of solution allowing us to overcome the problem of having a very low gain. From an optical point of view, in the range of wavelengths explored, there is a lack of transparents dielectric materials for substrates and coatings. Substrates are required at the same time to be relatively not absorbing (a few tens 10{sup -6}), to have a very good surface quality (RMS roughness below 10 {Angstrom}) because of scattering losses dramatically increasing in this spectral range and, due to the thermal load of the undulator emission, to have adequate thermal characteristics. In order to fulfill all these requirements, a good characterisation and modelisation of the substrates is needed, especially to correlate thermal loading and mechanical deformations from one hand, and roughness and scattering losses from the other hand. Coatings must be not absorbing too and, above all, the most amorphous as possible (this could be obtained with IBS deposition technique), in order to insure a good reproduction of the substrate roughness at the interfaces and on the top layer and an higher resistance to the XUV photons load.

  20. Scatterometry measurement precision and accuracy below 70 nm

    NASA Astrophysics Data System (ADS)

    Sendelbach, Matthew; Archie, Charles N.

    2003-05-01

    Scatterometry is a contender for various measurement applications where structure widths and heights can be significantly smaller than 70 nm within one or two ITRS generations. For example, feedforward process control in the post-lithography transistor gate formation is being actively pursued by a number of RIE tool manufacturers. Several commercial forms of scatterometry are available or under development which promise to provide satisfactory performance in this regime. Scatterometry, as commercially practiced today, involves analyzing the zeroth order reflected light from a grating of lines. Normal incidence spectroscopic reflectometry, 2-theta fixed-wavelength ellipsometry, and spectroscopic ellipsometry are among the optical techniques, while library based spectra matching and realtime regression are among the analysis techniques. All these commercial forms will find accurate and precise measurement a challenge when the material constituting the critical structure approaches a very small volume. Equally challenging is executing an evaluation methodology that first determines the true properties (critical dimensions and materials) of semiconductor wafer artifacts and then compares measurement performance of several scatterometers. How well do scatterometers track process induced changes in bottom CD and sidewall profile? This paper introduces a general 3D metrology assessment methodology and reports upon work involving sub-70 nm structures and several scatterometers. The methodology combines results from multiple metrologies (CD-SEM, CD-AFM, TEM, and XSEM) to form a Reference Measurement System (RMS). The methodology determines how well the scatterometry measurement tracks critical structure changes even in the presence of other noncritical changes that take place at the same time; these are key components of accuracy. Because the assessment rewards scatterometers that measure with good precision (reproducibility) and good accuracy, the most precise

  1. Multiple product pathways in photodissociation of nitromethane at 213 nm.

    PubMed

    Sumida, Masataka; Kohge, Yasunori; Yamasaki, Katsuyoshi; Kohguchi, Hiroshi

    2016-02-14

    In this paper, we present a photodissociation dynamics study of nitromethane at 213 nm in the π → π(*) transition. Resonantly enhanced multiphoton ionization spectroscopy and ion-imaging were applied to measure the internal state distributions and state-resolved scattering distributions of the CH3, NO(X (2)Π, A (2)Σ(+)), and O((3)PJ) photofragments. The rotationally state-resolved scattering distribution of the CH3 fragment showed two velocity components, of which the slower one decreased the relative intensity as the rotational and vibrational excitations. The translational energy distribution of the faster CH3 fragment indicated the production of the NO2 counter-product in the electronic excited state, wherein 1 (2)B2 was the most probable. The NO(v = 0) fragment exhibited a bimodal translational energy distribution, whereas the NO(v = 1 and 2) fragment exhibited a single translational energy component with a relatively larger internal energy. The translational energy of a portion of the O((3)PJ) photofragment was found to be higher than the one-photon dissociation threshold, indicating the two-photon process involved. The NO(A (2)Σ(+)) fragment, which was detected by ionization spectroscopy via the Rydberg ← A (2)Σ(+) transition, also required two-photon energy. These experimental data corroborate the existence of competing photodissociation product pathways, CH3 + NO2,CH3 + NO + O,CH3O + NO, and CH3NO + O, following the π → π(*) transition. The origins of the observed photofragments are discussed in this report along with recent theoretical studies and previous dynamics experiments performed at 193 nm. PMID:26874485

  2. Immediate reaction to clarithromycin.

    PubMed

    Gangemi, S; Ricciardi, L; Fedele, R; Isola, S; Purello-D'Ambrosio, F

    2001-01-01

    We present the case of bronchospastic reaction to clarithromycin had during a drug challenge test. Personal allergic history was negative for respiratory allergies and positive for adverse drug reactions to general and regional anesthesia and to ceftriaxone. After the administration of 1/4 of therapeutic dose of clarithromycin the patient showed dyspnea, cough and bronchospasm in all the lung fields. The positivity of the test was confirmed by the negativity to the administration of placebo. The quickness and the clinical characteristic of the adverse reaction suggest a pathogenic mechanism of immediate-type hypersensitivity. On reviewing the literature we have found no reports of bronchospastic reaction to clarithromycin. Macrolides are a class of antibiotics mainly used in the last years in place of beta-lactams because of a broad spectrum of action and a low allergic power. In fact, there are few reports on allergic reactions to these molecules. Clarithromycin is one of the latest macrolides, characterised by the presence of a 14-carbon-atom lactone ring as erythromycin, active on a wide spectrum of pathogens. PMID:11449533

  3. Find favorable reactions faster

    SciTech Connect

    Yaws, C.L.; Chiang, P.Y. )

    1988-11-01

    Now, equations are given to identify whether the reactions are thermodynamically favorable. The method uses Gibbs free energy of formation for the reactants and products. The equation for any 700 major organic compounds is given as temperature coefficients. Then the reaction can be tested at various temperature levels beyond the standard 298/sup 0/K conditions imposed by many other data tabulations. Data for the water and hydrogen chloride are also included. Gibbs free energy of formation of ideal gas (..delta..G/sub f/, jkoule/g-mol) is calculated from the tabulated coefficients (A, B, C) and the temperature (T, /sup 0/K) using the following equation: (1) ..delta..G/sub f/ = A + BT + CT/sup 2/. Chemical equilibrium for a reaction is associated with the change in Gibbs free energy (..delta..G/sub r/) calculated as follows: (2) ..delta..G/sub r/ = ..delta..G/sub f/, products - ..delta..G/sub f/, reactants. If the change in Gibbs free energy is negative, the thermodynamics for the reaction are favorable. On the other hand, if the change in Gibbs free energy is highly positive, the thermodynamics for the reaction are not favorable and may be feasible only under special circumstances.

  4. Standoff detection of biological agents using laser induced fluorescence—a comparison of 294 nm and 355 nm excitation wavelengths

    PubMed Central

    Farsund, Øystein; Rustad, Gunnar; Skogan, Gunnar

    2012-01-01

    Standoff detection measuring the fluorescence spectra of seven different biological agents excited by 294 nm as well as 355 nm wavelength laser pulses has been undertaken. The biological warfare agent simulants were released in a semi-closed aerosol chamber at 210 m standoff distance and excited by light at either of the two wavelengths using the same instrument. Significant differences in several of the agents’ fluorescence response were seen at the two wavelengths. The anthrax simulants’ fluorescence responses were almost an order of magnitude stronger at the shorter wavelength excitation. However, most importantly, the fluorescence spectra were significantly more dissimilar at 294 nm than at 355 nm excitation with ~7 nm spectral resolution. This indicates that classification of the substances should be possible with a lower error rate for standoff detection using 294 nm rather than 355 nm excitation wavelength, or even better, utilizing both. PMID:23162732

  5. Visible Light Mediated Photoredox Catalytic Arylation Reactions.

    PubMed

    Ghosh, Indrajit; Marzo, Leyre; Das, Amrita; Shaikh, Rizwan; König, Burkhard

    2016-08-16

    anion of the organic dye perylenediimide is excited by a second photon allowing the one electron reduction of acceptor substituted aryl chlorides. The radical anion of the aryl halide fragments under the loss of a halide ion and the aryl radical undergoes C-H arylation with biologically important pyrrole derivatives or adds to a double bond. Rhodamine 6G as an organic photocatalyst allows an even higher degree of control of the reaction. The dye is photoreduced in the presence of an amine donor under irradiation with green light (e.g., 530 nm), yielding its radical anion, which is a mild reducing reagent. The hypsochromic shift of the absorption of the rhodamine 6G radical anion toward blue region of the visible light spectrum allows its selective excitation using blue light (e.g., 455 nm). The excited radical anion is highly reducing and able to activate even bromoanisole for C-H arylation reactions, although only in moderate yield. Photoredox catalytic C-H arylation reactions are valuable alternatives to metal catalyzed reactions. They have an excellent functional group tolerance, could potentially avoid metal containing catalysts, and use visible light as a traceless reagent for the activation of arylating reagents. PMID:27482835

  6. Nanobumps on silicon created with polystyrene spheres and 248 or 308 nm laser pulses

    SciTech Connect

    Piparia, Reema; Rothe, Erhard W.; Baird, R. J.

    2006-11-27

    Huang et al. [Appl. Phys. Lett. 86, 161911 (2005)] formed arrays of nanobumps on a silicon substrate. They applied a 248 nm laser pulse to a surface monolayer of 1-{mu}m-diameter polystyrene spheres. The authors first replicated their experiment with 248 nm light. But when 308 nm pulses were applied instead, the nanobumps had a different shape and composition. At 248 nm, much of the laser light is absorbed in the polystyrene, which serves to quickly distort, melt, and ablate the sphere. At 308 nm, very little light is absorbed. The nanobumps from 248 nm radiation are organic polymers, while those formed with 308 nm pulses are silicon based.

  7. Nanoparticle Reactions on Chip

    NASA Astrophysics Data System (ADS)

    Köhler, J. M.; Kirner, Th.; Wagner, J.; Csáki, A.; Möller, R.; Fritzsche, W.

    The handling of heterogenous systems in micro reactors is difficult due to their adhesion and transport behaviour. Therefore, the formation of precipitates and gas bubbles has to be avoided in micro reaction technology, in most cases. But, micro channels and other micro reactors offer interesting possibilities for the control of reaction conditions and transport by diffusion and convection due to the laminar flow caused by small Reynolds numbers. This can be used for the preparation and modification of objects, which are much smaller than the cross section of microchannels. The formation of colloidal solutions and the change of surface states of nano particles are two important tasks for the application of chip reactors in nanoparticle technology. Some concepts for the preparation and reaction of nanoparticles in modular chip reactor arrangements will be discussed.

  8. Hipersensitivity Reactions to Corticosteroids.

    PubMed

    Berbegal, L; DeLeon, F J; Silvestre, J F

    2016-03-01

    Corticosteroids are widely used drugs in the clinical practice, especially by topic application in dermatology. These substances may act as allergens and produce immediate and delayed hypersensitivity reactions. Allergic contact dermatitis is the most frequent presentation of corticosteroid allergy and it should be studied by patch testing in specific units. The corticosteroids included in the Spanish standard battery are good markers but not ideal. Therefore, if those makers are positive, it is useful to apply a specific battery of corticosteroids and the drugs provided by patients. Immediate reactions are relatively rare but potentially severe, and it is important to confirm the sensitization profile and to guide the use of alternative corticosteroids, because they are often necessary in several diseases. In this article we review the main concepts regarding these two types of hypersensitivity reactions in corticosteroid allergy, as well as their approach in the clinical practice. PMID:26621334

  9. CW, single-frequency 229nm laser source for Cd-cooling by harmonic conversion

    NASA Astrophysics Data System (ADS)

    Kaneda, Yushi; Yarborough, J. M.; Merzlyak, Yevgeny

    2015-02-01

    More than 200mW of CW 229nm for Cd atom cooling application was generated by the 4th harmonic of a single frequency optically pumped semiconductor laser using a 10-mm long, Brewster-cut BBO crystal in an external cavity. With 650mW of 458nm input, 216mW of 229nm power was observed. Conversion efficiency from 458nm to 229nm was more than 33%.

  10. Cutaneous reactions to vaccinations.

    PubMed

    Rosenblatt, Adena E; Stein, Sarah L

    2015-01-01

    Vaccinations are important for infectious disease prevention; however, there are adverse effects of vaccines, many of which are cutaneous. Some of these reactions are due to nonspecific inflammation and irritation at the injection site, whereas other reactions are directly related to the live attenuated virus. Rarely, vaccinations have been associated with generalized hypersensitivity reactions, such as erythema multiforme, Stevens-Johnson syndrome, urticaria, acute generalized exanthematous pustulosis, and drug hypersensitivity syndrome. The onset of certain inflammatory dermatologic conditions, such as lichen planus, granuloma annulare, and pemphigoid, were reported to occur shortly after vaccine administration. Allergic contact dermatitis can develop at the injection site, typically due to adjuvant ingredients in the vaccine, such as thimerosal and aluminum. Vaccinations are important to promote development of both individual and herd immunity. Although most vaccinations are considered relatively safe, there may be adverse effects associated with any vaccine. Cutaneous manifestations make up a large portion of the types of reactions associated with vaccines. There are many different reasons for the development of a cutaneous reaction to a vaccination. Some are directly related to the injection of a live attenuated virus, such as varicella or vaccinia (for immunity to smallpox), whereas others cause more nonspecific erythema and swelling at the injection site, as a result of local inflammation or irritation. Vaccinations have also been associated in rare reports with generalized hypersensitivity reactions, such as erythema multiforme, Stevens-Johnson syndrome, urticaria, acute generalized exanthematous pustulosis, and drug hypersensitivity syndrome. There have been case reports associating the administration of a vaccine with the new onset of a dermatologic condition, such as lichen planus, granuloma annulare, and Sweet syndrome. Finally, allergic contact

  11. Mathematical simulation of the amplification of 1790-nm laser radiation in a nuclear-excited He – Ar plasma containing nanoclusters of uranium compounds

    SciTech Connect

    Kosarev, V A; Kuznetsova, E E

    2014-02-28

    The possibility of applying dusty active media in nuclearpumped lasers has been considered. The amplification of 1790-nm radiation in a nuclear-excited dusty He – Ar plasma is studied by mathematical simulation. The influence of nanoclusters on the component composition of the medium and the kinetics of the processes occurring in it is analysed using a specially developed kinetic model, including 72 components and more than 400 reactions. An analysis of the results indicates that amplification can in principle be implemented in an active laser He – Ar medium containing 10-nm nanoclusters of metallic uranium and uranium dioxide. (lasers)

  12. Velocity pump reaction turbine

    DOEpatents

    House, P.A.

    An expanding hydraulic/two-phase velocity pump reaction turbine including a dual concentric rotor configuration with an inter-rotor annular flow channel in which the inner rotor is mechanically driven by the outer rotor. In another embodiment, the inner rotor is immobilized and provided with gas recovery ports on its outer surface by means of which gas in solution may be recovered. This velocity pump reaction turbine configuration is capable of potential energy conversion efficiencies of up to 70%, and is particularly suited for geothermal applications.

  13. Velocity pump reaction turbine

    DOEpatents

    House, Palmer A.

    1984-01-01

    An expanding hydraulic/two-phase velocity pump reaction turbine including a dual concentric rotor configuration with an inter-rotor annular flow channel in which the inner rotor is mechanically driven by the outer rotor. In another embodiment, the inner rotor is immobilized and provided with gas recovery ports on its outer surface by means of which gas in solution may be recovered. This velocity pump reaction turbine configuration is capable of potential energy conversion efficiencies of up to 70%, and is particularly suited for geothermal applications.

  14. Velocity pump reaction turbine

    DOEpatents

    House, Palmer A.

    1982-01-01

    An expanding hydraulic/two-phase velocity pump reaction turbine including a dual concentric rotor configuration with an inter-rotor annular flow channel in which the inner rotor is mechanically driven by the outer rotor. In another embodiment, the inner rotor is immobilized and provided with gas recovery ports on its outer surface by means of which gas in solution may be recovered. This velocity pump reaction turbine configuration is capable of potential energy conversion efficiencies of up to 70%, and is particularly suited for geothermal applications.

  15. Synthesis and solvent-dependent photochromic reactions of porphyrin-spiropyran hybrid compounds

    NASA Astrophysics Data System (ADS)

    Hur, Dae Young; Park, Tae Jong; Shin, Eun Ju

    2014-01-01

    Porphyrin(Por)-spiropyran(SP) hybrid compounds, including Por-SP dyad, Por-SP2 triad, and Por-SP4 pentad, were prepared and characterized by 1H NMR, MALDI-TOF MS and UV-Vis spectroscopies. Upon 350 nm UV irradiation of Por-SPn (n = 1, 2, 4) in dichloromethane, unusual red-shifted absorption spectra were observed with the colour change from pink into green. Probably due to the protonation of core nitrogens in porphyrin ring, their absorption maxima in dichloromethane were shifted from 418 (Soret band), 515, 550, 590, 645 (four Q bands) nm into 450 and 665 nm. Also, fluorescence maxima were also shifted from 650 and 715 nm to 692 nm. In the other hands, upon irradiation with 350 nm UV light in THF, the colour changed from pink into violet and absorption band at 590 nm increased and the fluorescence spectra showed the decrease of 650 and 715 nm bands and increase of 600-640 nm band, due to the normal ring-opening reaction of spiropyran moiety into merocyanine. In the dark, original absorption and fluorescence spectra were recovered very slowly in dichloromethane, but quickly in THF. The reversible photochromic reactions of Por-SPn (n = 1, 2, 4) in dichloromethane and THF were investigated by observing absorption and fluorescence spectral changes during UV irradiation or standing in the dark.

  16. A Sounding Rocket Mission Concept to Acquire High-Resolution Radiometric Spectra Spanning the 9 nm - 31 nm Wavelength Range

    NASA Technical Reports Server (NTRS)

    Krause, L. Habash; Cirtain, Jonathan; McGuirck, Michael; Pavelitz, Steven; Weber, Ed.; Winebarger, Amy

    2012-01-01

    When studying Solar Extreme Ultraviolet (EUV) emissions, both single-wavelength, two- dimensional (2D) spectroheliograms and multi-wavelength, one-dimensional (1D) line spectra are important, especially for a thorough understanding of the complex processes in the solar magnetized plasma from the base of the chromosphere through the corona. 2D image data are required for a detailed study of spatial structures, whereas radiometric (i.e., spectral) data provide information on relevant atomic excitation/ionization state densities (and thus temperature). Using both imaging and radiometric techniques, several satellite missions presently study solar dynamics in the EUV, including the Solar Dynamics Observatory (SDO), Hinode, and the Solar-Terrestrial Relations Observatory (STEREO). The EUV wavelengths of interest typically span 9 nm to 31 nm, with the shorter wavelengths being associated with the hottest features (e.g., intense flares and bright points) and the longer wavelengths associated with cooler features (e.g., coronal holes and filaments). Because the optical components of satellite instruments degrade over time, it is not uncommon to conduct sounding rocket underflights for calibration purposes. The authors have designed a radiometric sounding rocket payload that could serve as both a calibration underflight for and a complementary scientific mission to the upcoming Solar Ultraviolet Imager (SUVI) mission aboard the GOES-R satellite (scheduled for a 2015 launch). The challenge to provide quality radiometric line spectra over the 9-31 nm range covered by SUVI was driven by the multilayer coatings required to make the optical components, including mirrors and gratings, reflective over the entire range. Typically, these multilayers provide useful EUV reflectances over bandwidths of a few nm. Our solution to this problem was to employ a three-telescope system in which the optical components were coated with multilayers that spanned three wavelength ranges to cover

  17. NM counts in relation to CMEs and Magnetic fields

    NASA Astrophysics Data System (ADS)

    Mishra, Rajesh Kumar; Agarwal, Rekha

    2016-07-01

    The global network of neutron monitors (NMs) have provided data to the heliophysics community for over sixty years to study the time variations of the galactic cosmic ray (GCR) intensity. Simpson recommended a standard NM for worldwide use during the International Geophysical Year (IGY, 1957-58). NM data have been used extensively for the time variation studies ranging from minutes to decades. Coronal Mass Ejections are vast structures of plasma and magnetic fields that are expelled from the sun into the heliosphere, which is detected by remote sensing and in-situ spacecraft observations. The present study is related with behaviour of four types of CMEs namely Asymmetric 'Full' Halo CMEs, Partial Halo CMEs, Asymmetric and Complex 'Full' Halo CMEs and 'Full' Halo CMEs on cosmic ray neutron monitor intensity. The data of two different ground based neutron monitors having different cutoff rigidity threshold and CME events observed with instruments onboard and Wind spacecraft have been used in the present work. The superposed epoch (Chree) analysis has been applied to the arrival times of these CMEs. The occurrence frequency of three different types of CMEs used in the present analysis shows complex behavior. Significant fluctuations in cosmic ray intensity is observed few days after the onset of asymmetric full halo and few days after the onset of full halo CMEs. The fluctuations in cosmic ray intensity are more prior to the onset of both types of the CMEs. However, during Partial Halo CMEs the cosmic ray intensity peaks, 8- 9 days prior to the onset of CMEs and depressed 3 days prior to the onset of CMEs, whereas in case of asymmetric and complex full CMEs, the intensity depressed 2 days prior to the onset of CMEs and enhanced 2 days after the onset of CMEs. The deviations in cosmic ray intensity are more pronounced in case for asymmetric and complex full halo CMEs compared to other CMEs. The cosmic ray intensity shows nearly good anti-correlation with interplanetary

  18. Laser-Matter Interactions with a 527 nm Drive

    SciTech Connect

    Glenzer, S; Niemann, C; Witman, P; Wegner, P; Mason, D; Haynam, C; Parham, T; Datte, P

    2007-02-16

    The primary goal of this Exploratory Research is to develop an understanding of laser-matter interactions with 527-nm light (2{omega}) for studies of interest to numerous Laboratory programs including inertial confinement fusion (ICF), material strength, radiation transport, and hydrodynamics. In addition, during the course of this work we will develop the enabling technology and prototype instrumentation to diagnose a high fluence laser beam for energy, power, and near field intensity profile at 2{omega}. Through this Exploratory Research we have established an extensive experimental and modeling data base on laser-matter interaction with 527 nm laser light (2{omega}) in plasma conditions of interest to numerous Laboratory programs. The experiments and the laser-plasma interaction modeling using the code pF3D have shown intensity limits and laser beam conditioning requirements for future 2{omega} laser operations and target physics experiments on the National Ignition Facility (NIF). These findings have set requirements for which present radiation-hydrodynamic simulations indicate the successful generation of relevant pressure regimes in future 2{omega} experiments. To allow these experiments on the NIF, optics and optical mounts were prepared for the 18mm Second Harmonic Generation Crystal (SHG crystal) that would provide the desired high conversion efficiency from 1{omega} to 2{omega}. Supporting experimental activities on NIF included high-energy 1{omega} shots at up to 22kJ/beamline (4MJ full NIF 1{omega} equivalent energy) that demonstrated, in excess, the 1{omega} drive capability of the main laser that is required for 2{omega} operations. Also, a very extensive 3{omega} campaign was completed (see ''The National Ignition Facility Laser Performance Status'' UCRL-JRNL-226553) that demonstrated that not only doubling the laser, but also tripling the laser (a much more difficult and sensitive combination) met our model predictions over a wide range of laser

  19. Double pattern EDA solutions for 32nm HP and beyond

    NASA Astrophysics Data System (ADS)

    Bailey, George E.; Tritchkov, Alexander; Park, Jea-Woo; Hong, Le; Wiaux, Vincent; Hendrickx, Eric; Verhaegen, Staf; Xie, Peng; Versluijs, Janko

    2007-03-01

    The fate of optical-based lithography hinges on the ability to deploy viable resolution enhancement techniques (RET). One such solution is double patterning (DP). Like the double-exposure technique, double patterning is a decomposition of the design to relax the pitch that requires dual masks, but unlike double-exposure techniques, double patterning requires an additional develop and etch step, which eliminates the resolution degradation due to the cross-coupling that occurs in the latent images of multiple exposures. This additional etch step is worth the effort for those looking for an optical extension [1]. The theoretical k I for a double-patterning technique of a 32nm half-pitch (HP) design for a 1.35NA 193nm imaging system is 0.44 whereas the k I for a single-exposure technique of this same design would be 0.22 [2], which is sub-resolution. There are other benefits to the DP technique such as the ability to add sub-resolution assist features (SRAF) in the relaxed pitch areas, the reduction of forbidden pitches, and the ability to apply mask biases and OPC without encountering mask constraints. Similarly to AltPSM and SRAF techniques one of the major barriers to widespread deployment of double patterning to random logic circuits is design compliance with split layout synthesis requirements [3]. Successful implementation of DP requires the evolution and adoption of design restrictions by specifically tailored design rules. The deployment of double patterning does spawn a couple of issues that would need addressing before proceeding into a production environment. As with any dual-mask RET application, there are the classical overlay requirements between the two exposure steps and there are the complexities of decomposing the designs to minimize the stitching but to maximize the depth of focus (DoF). In addition, the location of the design stitching would require careful consideration. For example, a stitch in a field region or wider lines is preferred over a

  20. UV 380 nm Reflectivity of the Earth's Surface

    NASA Technical Reports Server (NTRS)

    Herman, J. R.; Celarier, E.; Larko, D.

    2000-01-01

    The 380 nm radiance measurements of TOMS (Total Ozone Mapping Spectrometer) have been converted into a global data set of daily (1979 to 1992) Lambert equivalent reflectivities R of the Earth's surface and boundary layer (clouds, aerosols, surface haze, and snow/ice). Since UV surface reflectivity is between 2 and 8% for both land and water during all seasons of the year (except for ice and snow cover), reflectivities larger than the surface value indicates the presence of clouds, haze, or aerosols in the satellite field of view. Statistical analysis of 14 years of daily data show that most snow/ice-free regions of the Earth have their largest fraction of days each year when the reflectivity is low (R less than 10%). The 380 nm reflectivity data shows that the true surface reflectivity is 2 to 3% lower than the most frequently occurring reflectivity value for each TOMS scene. The most likely cause of this could be a combination of frequently occurring boundary-layer water or aerosol haze. For most regions, the observation of extremely clear conditions needed to estimate the surface reflectivity from space is a comparatively rare occurrence. Certain areas (e.g., Australia, southern Africa, portions of northern Africa) are cloud-free more than 80% of the year, which exposes these regions to larger amounts of UV radiation than at comparable latitudes in the Northern Hemisphere. Regions over rain-forests, jungle areas, Europe and Russia, the bands surrounding the Arctic and Antarctic regions, and many ocean areas have significant cloud cover (R greater than 15%) more than half of each year. In the low to middle latitudes, the areas with the heaviest cloud cover (highest reflectivity for most of the year) are the forest areas of northern South America, southern Central America, the jungle areas of equatorial Africa, and high mountain regions such as the Himalayas or the Andes. The TOMS reflectivity data show the presence of large nearly clear ocean areas and the effects

  1. Lactones in 193 nm resists: What do they do?

    NASA Astrophysics Data System (ADS)

    Ito, Hiroshi; Truong, Hoa D.; Brock, Phil J.

    2008-03-01

    Lactones are almost ubiquitously employed in 193 nm resists to increase the polarity of hydrophobic alicyclic polymers. What else do lactones do in 193 nm resists? We studied the behavior of methacrylate (MA) resists consisting of different protecting groups, hexafluoroalcohols, and norbornane lactone methacrylate (NLM, 2-oxo-3-oxatricyclo[4.2.1.04,8]nonan-5-yl methacrylate). When the protecting group is large [ethylcyclooctyl (ECO) and methyladamantyl (MAd)], thinning of the resist film that occurs in highly exposed areas upon postexposure bake (PEB) is significantly smaller than what is expected from the polymer composition. When the concentration of isopropylhexafluoroalcohol methacrylate (iPrHFAMA) is increased in the ECOMA-NLM polymer, the thinning increases and reaches 100% of theory and the ECOMA-norbornenehexafluoroalcohol methacrylate (NBHFAMA) resist loses quantitative thickness in highly-exposed areas upon PEB at 90 °C. This indicates that small lactones which are more basic than esters can trap deprotection fragments especially when the protecting group is large. Such entrapment was detected by IR spectroscopy and also observed at temperatures as high as 200 °C in thermogravimetric analysis (TGA). Incorporation of lactone appears to decrease the bake temperature sensitivity and the sensitivity of the resist perhaps due to trapping of photochemically generated acids by basic lactone. The lactone ring can be hydrolyzed during aqueous base development but does not seem to affect the dissolution rate, indicating that hydrolysis occurs in aqueous base solution after dissolution. Poly(methacrylic acid-NLM) dissolves as fast as poly(methacrylic acid) in 0.26 N tetramethylammonium hydroxide (TMAH) aqueous solution. While exposed P(ECOMA 47-NLM 53) resist dissolves in 0.26 N developer at about the same rate as authentically prepared poly(methacrylic acid 47-NLM 53), the dissolution rate of highly-exposed P(MAdMA 44-NLM 56) resist is much slower, indicating

  2. Strain relaxation in nm-thick Cu and Cu-alloy films bonded to a rigid substrate

    NASA Astrophysics Data System (ADS)

    Herrmann, Ashley Ann Elizabeth

    In the wide scope of modern technology, nm-thick metallic films are increasingly used as lubrication layers, optical coatings, plating seeds, diffusion barriers, adhesion layers, metal contacts, reaction catalyzers, etc. A prominent example is the use of nm-thick Cu films as electroplating seed layers in the manufacturing of integrated circuits (ICs). These high density circuits are linked by on-chip copper interconnects, which are manufactured by filling Cu into narrow trenches by electroplating. The Cu fill by electroplating requires a thin Cu seed deposited onto high-aspect-ratio trenches. In modern ICs, these trenches are approaching 10 nm or less in width, and the seed layers less than 1 nm in thickness. Since nm-thick Cu seed layers are prone to agglomeration or delamination, achieving uniform, stable and highly-conductive ultra-thin seeds has become a major manufacturing challenge. A fundamental understanding of the strain behavior and thermal stability of nm-thick metal films adhered to a rigid substrate is thus critically needed. In this study, we focus on understanding the deformation modes of nm-thick Cu and Cu-alloy films bonded to a rigid Si substrate and under compressive stress. The strengthening of Cu films through alloying is also studied. In-situ transport measurements are used to monitor the deformation of such films as they are heated from room temperature to 400 °C. Ex-situ AFM is then used to help characterize the mode of strain relaxation. The relaxation modes are known to be sensitive to the wetting and adhesive properties of the film-substrate interface. We use four different liners (Ta, Ru, Mo and Co), interposed between the film and substrate to provide a wide range of interfacial properties to study their effect on the film's thermal stability. Our measurements indicate that when the film/liner interfacial energy is low, grain growth is the dominant relaxation mechanism. As the interface energy increases, grain growth is suppressed, and

  3. Quinoprotein-catalysed reactions.

    PubMed Central

    Anthony, C

    1996-01-01

    This review is concerned with the structure and function of the quinoprotein enzymes, sometimes called quinoenzymes. These have prosthetic groups containing quinones, the name thus being analogous to the flavoproteins containing flavin prosthetic groups. Pyrrolo-quinoline quinone (PQQ) is non-covalently attached, whereas tryptophan tryptophylquinone (TTQ), topaquinone (TPQ) and lysine tyrosylquinone (LTQ) are derived from amino acid residues in the backbone of the enzymes. The mechanisms of the quinoproteins are reviewed and related to their recently determined three-dimensional structures. As expected, the quinone structures in the prosthetic groups play important roles in the mechanisms. A second common feature is the presence of a catalytic base (aspartate) at the active site which initiates the reactions by abstracting a proton from the substrate, and it is likely to be involved in multiple reactions in the mechanism. A third common feature of these enzymes is that the first part of the reaction produces a reduced prosthetic group; this part of the mechanism is fairly well understood. This is followed by an oxidative phase involving electron transfer reactions which remain poorly understood. In both types of dehydrogenase (containing PQQ and TTQ), electrons must pass from the reduced prosthetic group to redox centres in a second recipient protein (or protein domain), whereas in amine oxidases (containing TPQ or LTQ), electrons must be transferred to molecular oxygen by way of a redox-active copper ion in the protein. PMID:9003352

  4. Chain Reaction Polymerization.

    ERIC Educational Resources Information Center

    McGrath, James E.

    1981-01-01

    The salient features and importance of chain-reaction polymerization are discussed, including such topics as the thermodynamics of polymerization, free-radical polymerization kinetics, radical polymerization processes, copolymers, and free-radical chain, anionic, cationic, coordination, and ring-opening polymerizations. (JN)

  5. Exocharmic Reactions up Close

    ERIC Educational Resources Information Center

    Ramette, R. W.

    2007-01-01

    The exocharmic reactions that can be observed microscopically are discussed. The students can discover the optimal concentration of an acidic lead nitrate solution, so that a crystal of potassium iodide, nudged to the edge of a drop, results in glinting golden hexagons of lead iodide.

  6. Chemical Reactions at Surfaces

    SciTech Connect

    Michael Henderson and Nancy Ryan Gray

    2010-04-14

    Chemical reactions at surfaces underlie some of the most important processes of today, including catalysis, energy conversion, microelectronics, human health and the environment. Understanding surface chemical reactions at a fundamental level is at the core of the field of surface science. The Gordon Research Conference on Chemical Reactions at Surfaces is one of the premiere meetings in the field. The program this year will cover a broad range of topics, including heterogeneous catalysis and surface chemistry, surfaces in environmental chemistry and energy conversion, reactions at the liquid-solid and liquid-gas interface, electronic materials growth and surface modification, biological interfaces, and electrons and photons at surfaces. An exciting program is planned, with contributions from outstanding speakers and discussion leaders from the international scientific community. The conference provides a dynamic environment with ample time for discussion and interaction. Attendees are encouraged to present posters; the poster sessions are historically well attended and stimulate additional discussions. The conference provides an excellent opportunity for junior researchers (e.g. graduate students or postdocs) to present their work and interact with established leaders in the field.

  7. Radiobiology of tissue reactions.

    PubMed

    Dörr, W

    2015-06-01

    Tissue effects of radiation exposure are observed in virtually all normal tissues, with interactions when several organs are involved. Early reactions occur in turnover tissues, where proliferative impairment results in hypoplasia; late reactions, based on combined parenchymal, vascular, and connective tissue changes, result in loss of function within the exposed volume; consequential late effects develop through interactions between early and late effects in the same organ; and very late effects are dominated by vascular sequelae. Invariably, involvement of the immune system is observed. Importantly, latent times of late effects are inversely dependent on the biologically equieffective dose. Each tissue component and--importantly--each individual symptom/endpoint displays a specific dose-effect relationship. Equieffective doses are modulated by exposure conditions: in particular, dose-rate reduction--down to chronic levels--and dose fractionation impact on late responding tissues, while overall exposure time predominantly affects early (and consequential late) reactions. Consequences of partial organ exposure are related to tissue architecture. In 'tubular' organs (gastrointestinal tract, but also vasculature), punctual exposure affects function in downstream compartments. In 'parallel' organs, such as liver or lungs, only exposure of a significant (organ-dependent) fraction of the total volume results in clinical consequences. Forthcoming studies must address biomarkers of the individual risk for tissue reactions, and strategies to prevent/mitigate tissue effects after exposure. PMID:25816259

  8. Reaction and Response.

    ERIC Educational Resources Information Center

    Armento, Beverly J.; And Others

    1993-01-01

    Provides a reaction by three economic educators to an article by Raymond C. Miller calling for the elimination of economics. Contends that traditional economics does not necessarily lead to the degradation of the environment. Argues that economics should not promote any set of social values. (CFR)

  9. A Principal's Reaction

    ERIC Educational Resources Information Center

    Zaretsky, Lindy

    2004-01-01

    This article presents a principal's reaction to Catherine Marshall and Michael Ward's article on research on social justice and training for leadership. The author applauds Marshall and Ward's efforts to address what is undoubtedly among the most fundamentally important issues facing principals today. Marshall and Ward illuminate the importance of…

  10. Reaction product imaging

    SciTech Connect

    Chandler, D.W.

    1993-12-01

    Over the past few years the author has investigated the photochemistry of small molecules using the photofragment imaging technique. Bond energies, spectroscopy of radicals, dissociation dynamics and branching ratios are examples of information obtained by this technique. Along with extending the technique to the study of bimolecular reactions, efforts to make the technique as quantitative as possible have been the focus of the research effort. To this end, the author has measured the bond energy of the C-H bond in acetylene, branching ratios in the dissociation of HI, the energetics of CH{sub 3}Br, CD{sub 3}Br, C{sub 2}H{sub 5}Br and C{sub 2}H{sub 5}OBr dissociation, and the alignment of the CD{sub 3} fragment from CD{sub 3}I photolysis. In an effort to extend the technique to bimolecular reactions the author has studied the reaction of H with HI and the isotopic exchange reaction between H and D{sub 2}.

  11. Reactions to Others' Intimacy.

    ERIC Educational Resources Information Center

    Neufeldt, David E.; Olinger, Evanelle J.

    Research using behavioral measures has indicated that men react less positively to the touch of a same sex individual than women, that both men and women react more positively to the touch of an opposite sex individual than to the touch of a same sex individual, and that men and women do not differ in their reactions to opposite sex touch. This…

  12. Polymerase chain reaction system

    DOEpatents

    Benett, William J.; Richards, James B.; Stratton, Paul L.; Hadley, Dean R.; Milanovich, Fred P.; Belgrader, Phil; Meyer, Peter L.

    2004-03-02

    A portable polymerase chain reaction DNA amplification and detection system includes one or more chamber modules. Each module supports a duplex assay of a biological sample. Each module has two parallel interrogation ports with a linear optical system. The system is capable of being handheld.

  13. A Superintendent's Reaction

    ERIC Educational Resources Information Center

    Lytle, James H.

    2004-01-01

    This article presents a superintendent's reaction to Catherine Marshall and Michael Ward's article on research on social justice and training for leadership. The author states that there is a problem with Marshall and Ward's article which begins with the title, particularly with the word "training." The author contends that there is a significant…

  14. Enantioselective Vinylogous Organocascade Reactions.

    PubMed

    Hepburn, Hamish B; Dell'Amico, Luca; Melchiorre, Paolo

    2016-08-01

    Cascade reactions are powerful tools for rapidly assembling complex molecular architectures from readily available starting materials in a single synthetic operation. Their marriage with asymmetric organocatalysis has led to the development of novel techniques, which are now recognized as reliable strategies for the one-pot enantioselective synthesis of stereochemically dense molecules. In recent years, even more complex synthetic challenges have been addressed by applying the principle of vinylogy to the realm of organocascade catalysis. The key to the success of vinylogous organocascade reactions is the unique ability of the chiral organocatalyst to transfer reactivity to a distal position without losing control on the stereo-determining events. This approach has greatly expanded the synthetic horizons of the field by providing the possibility of forging multiple stereocenters in remote positions from the catalyst's point of action with high selectivity, while simultaneously constructing multiple new bonds. This article critically describes the developments achieved in the field of enantioselective vinylogous organocascade reactions, charting the ideas, the conceptual advances, and the milestone reactions that have been essential for reaching highly practical levels of synthetic efficiency. PMID:27256039

  15. Reaction Formulation: A Bibliography.

    ERIC Educational Resources Information Center

    Pedrini, D. T.; Pedrini, Bonnie C.

    Reaction formation was studied by Sigmund Freud. This defense mechanism may be related to repression, substitution, reversal, and compensation (or over-compensation). Alfred Adler considered compensation a basic process in his individual psychology. Anna Freud discussed some defense mechanisms, and Bibring, Dwyer, Huntington, and Valenstein…

  16. Azlactone Reaction Developments.

    PubMed

    de Castro, Pedro P; Carpanez, Arthur G; Amarante, Giovanni W

    2016-07-18

    Azlactones (also known as oxazolones) are heterocycles usually employed in the stereoselective synthesis of α,α-amino acids, heterocycles and natural products. The versatility of the azlactone scaffold arises from the numerous reactive sites, allowing its application in a diversity of transformations. This review aims to cover classical and recent applications of oxazolones, especially those involving stereoselective processes. After a short introduction on their structures and intrinsic reactivities, dynamic kinetic resolution (DKR) processes as well as reactions involving stereoselective formation of a new σ C-C bond, such as alkylation/allylation/arylation, aldol, ene, Michael and Mannich reactions will be exposed. Additionally, cycloadditions, Steglich rearrangement and sulfenylation reactions will also be discussed. Recent developments of the well-known Erlenmeyer azlactones will be described. For the most examples, the proposed mechanism, activation modes and/or key reaction intermediates will be exposed to rationalize both the final product and the observed stereochemistry. Finally, this review gives an overview of the synthetic utility of oxazolones. PMID:27245128

  17. Synthesis of 10 nm β-NaYF4:Yb,Er/NaYF4 Core/Shell Upconversion Nanocrystals with 5 nm Particle Cores.

    PubMed

    Rinkel, Thorben; Raj, Athira Naduviledathu; Dühnen, Simon; Haase, Markus

    2016-01-18

    A new method is presented for preparing gram amounts of very small core/shell upconversion nanocrystals without additional codoping of the particles. First, ca. 5 nm β-NaYF4:Yb,Er core particles are formed by the reaction of sodium oleate, rare-earth oleate, and ammonium fluoride, thereby making use of the fact that a high ratio of sodium to rare-earth ions promotes the nucleation of a large number of β-phase seeds. Thereafter, a 2 nm thick NaYF4 shell is formed by using 3-4 nm particles of α-NaYF4 as a single-source precursor for the β-phase shell material. In contrast to the core particles, however, these α-phase particles are prepared with a low ratio of sodium to rare-earth ions, which efficiently suppresses an undesired nucleation of β-NaYF4 particles during shell growth. PMID:26633748

  18. Photoneutron reactions in astrophysics

    SciTech Connect

    Varlamov, V. V. Ishkhanov, B. S.; Orlin, V. N.; Peskov, N. N.; Stopani, K. A.

    2014-12-15

    Among key problems in nuclear astrophysics, that of obtaining deeper insight into the mechanism of synthesis of chemical elements is of paramount importance. The majority of heavy elements existing in nature are produced in stars via radiative neutron capture in so-called s- and r processes, which are, respectively, slow and fast, in relation to competing β{sup −}-decay processes. At the same time, we know 35 neutron-deficient so-called bypassed p-nuclei that lie between {sup 74}Se and {sup 196}Hg and which cannot originate from the aforementioned s- and r-processes. Their production is possible in (γ, n), (γ, p), or (γ, α) photonuclear reactions. In view of this, data on photoneutron reactions play an important role in predicting and describing processes leading to the production of p-nuclei. Interest in determining cross sections for photoneutron reactions in the threshold energy region, which is of particular importance for astrophysics, has grown substantially in recent years. The use of modern sources of quasimonoenergetic photons obtained in processes of inverse Compton laser-radiation scattering on relativistic electronsmakes it possible to reveal rather interesting special features of respective cross sections, manifestations of pygmy E1 and M1 resonances, or the production of nuclei in isomeric states, on one hand, and to revisit the problem of systematic discrepancies between data on reaction cross sections from experiments of different types, on the other hand. Data obtained on the basis of our new experimental-theoretical approach to evaluating cross sections for partial photoneutron reactions are invoked in considering these problems.

  19. High-power operation of silica-based Raman fiber amplifier at 2147 nm.

    PubMed

    Liu, Jiang; Tan, Fangzhou; Shi, Hongxing; Wang, Pu

    2014-11-17

    We demonstrated a 2147 nm silica-based Raman fiber amplifier with output power of 14.3 W directly pumped with a 1963 nm CW thulium-doped all-fiber MOPA. The 1963 nm thulium-doped all-fiber MOPA is seeded with a 2147 nm thulium-doped all-fiber laser at the same time. The Raman Stokes power shift from 1963 nm to 2147 nm is accomplished in a piece of 50 m silica-based highly nonlinear fiber (HNLF). The conversion efficiency was 38.5% from 1963 nm to 2147 nm in the HNLF. The output power achieved was only currently limited by available 1963 nm input power and the architecture has significant scaling potential. To the best of our knowledge, this is the highest power operation of a Raman fiber amplifier at >2 µm wavelength region. PMID:25402080

  20. Laser stabilization at 1536 nm using regenerative spectral hole burning

    NASA Astrophysics Data System (ADS)

    Sellin, P. B.; Strickland, N. M.; Böttger, T.; Carlsten, J. L.; Cone, R. L.

    2001-04-01

    Laser frequency stabilization giving a 500-Hz Allan deviation for a 2-ms integration time with drift reduced to 7 kHz/min over several minutes was achieved at 1536 nm in the optical communication band. A continuously regenerated spectral hole in the inhomogeneously broadened 4I15/2(1)-->4I13/2(1) optical absorption of an Er3+:Y2SiO5 crystal was used as the short-term frequency reference, while a variation on the locking technique allowed simultaneous use of the inhomogeneously broadened absorption line as a long-term reference. The reported frequency stability was achieved without vibration isolation. Spectral hole burning frequency stabilization provides ideal laser sources for high-resolution spectroscopy, real-time optical signal processing, and a range of applications requiring ultra-narrow-band light sources or coherent detection; the time scale for stability and the compatibility with spectral hole burning devices make this technique complementary to other frequency references for laser stabilization.

  1. Thin film type 248-nm bottom antireflective coatings

    NASA Astrophysics Data System (ADS)

    Enomoto, Tomoyuki; Nakayama, Keisuke; Mizusawa, Kenichi; Nakajima, Yasuyuki; Yoon, Sangwoong; Kim, Yong-Hoon; Kim, Young-Ho; Chung, Hoesik; Chon, Sang Mun

    2003-06-01

    A frequent problem encountered by photoresists during the manufacturing of semiconductor device is that activating radiation is reflected back into the photoresist by the substrate. So, it is necessary that the light reflection is reduced from the substrate. One approach to reduce the light reflection is the use of bottom anti-reflective coating (BARC) applied to the substrate beneath the photoresist layer. The BARC technology has been utilized for a few years to minimize the reflectivity. As the chip size is reduced to sub 0.13-micron, the photoresist thickness has to decrease with the aspect ratio being less than 3.0. Therefore, new Organic BARC is strongly required which has the minimum reflectivity with thinner BARC thickness and higher etch selectivity towards resist. SAMSUNG Electronics has developed the advanced Organic BARC with Nissan Chemical Industries, Ltd. and Brewer Science, Inc. for achieving the above purpose. As a result, the suitable high performance SNAC2002 series KrF Organic BARCs were developed. Using CF4 gas as etchant, the plasma etch rate of SNAC2002 series is about 1.4 times higher than that of conventional KrF resists and 1.25 times higher than the existing product. The SNAC2002 series can minimize the substrate reflectivity at below 40nm BARC thickness, shows excellent litho performance and coating properties.

  2. Analysis of wafer heating in 14nm DUV layers

    NASA Astrophysics Data System (ADS)

    Subramany, Lokesh; Chung, Woong Jae; Samudrala, Pavan; Gao, Haiyong; Aung, Nyan; Gomez, Juan Manuel; Minghetti, Blandine; Lee, Shawn

    2016-03-01

    To further shrink the contact and trench dimensions, Negative Tone Development (NTD) has become the de facto process at these layers. The NTD process uses a positive tone resist and an organic solvent-based negative tone developer which leads to improved image contrast, larger process window and smaller Mask Error Enhancement Factor (MEEF)[1]. The NTD masks have high transmission values leading to lens heating and as observed here wafer heating as well. Both lens and wafer heating will contribute to overlay error, however the effects of lens heating can be mitigated by applying lens heating corrections while no such corrections exist for wafer heating yet. Although the magnitude of overlay error due to wafer heating is low relative to lens heating; ever tightening overlay requirements imply that the distortions due to wafer heating will quickly become a significant part of the overlay budget. In this work the effects, analysis and observations of wafer heating on contact and metal layers of the 14nm node are presented. On product wafers it manifests as a difference in the scan up and scan down signatures between layers. An experiment to further understand wafer heating is performed with a test reticle that is used to monitor scanner performance.

  3. Mosaic of Jupiter's Great Red Spot (727 nm)

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The Great Red Spot of Jupiter as seen through a 'Methane' filter (727 nm) of the Galileo imaging system. The image is a mosaic of six images that have been map-projected to a uniform grid of latitude and longitude. North is at the top. The mosaic was taken over a 76 second interval beginning at universal time 14 hours, 31 minutes, 52 seconds on June 26, 1996. The Red Spot is 20,000 km long and has been followed by observers on Earth since the telescope was invented 300 years ago. It is a huge storm made visible by variations in the composition of the cloud particles. The Red Spot is not unique, but is simply the largest of a class of long-lived vortices, some of which are visible in the lower part of the image. The range is 1.46 million kilometers.

    The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC.

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

  4. First results from AIMS beta tool for 157-nm lithography

    NASA Astrophysics Data System (ADS)

    Teuber, Silvio; Higashikawa, Iwao; Urbach, Jan-Peter; Schilz, Christof M.; Koehle, Roderick; Zibold, Axel M.

    2004-05-01

    In modern mask manufacturing, a successful defect mitigation strategy has been become crucial to achieve defect free masks for high-end lithography. The basic steps of such a strategy include inspection, repair, and subsequent post-repair qualification of repair sites. For the latter task, actinic aerial image measurements have been proven to be the technique of choice to assess the printability of a repaired site. In the last three years, International SEMATECH in cooperation with Infineon/AMTC-Dresden and SELETE, funded a joint development project at Carl Zeiss to develop an AIMS tool operating at the 157nm wavelength. The three beta tools were shipped in 2003 to the three beta customer sites. In this paper are presented the first results obtained with these beta tools, including measurements on binary as well as alternating phase shift masks. The technical properties of the tool were discussed with regards to the capability of the tool for defect qualification on photomasks. Additionally, preliminary results of the evaluation of alternating phase shift masks will be discussed, including measurements performed on dense lines-and-spaces structures with various pitch sizes.

  5. Ageing of optical components under laser irradiation at 532nm

    NASA Astrophysics Data System (ADS)

    Becker, S.; Delrive, L.; Bouchut, P.; Andre, B.; Geffraye, F.

    2005-09-01

    The pulsed Laser Induced Damage Threshold (LIDT) of optical components usually reaches several hundreds of MW/cm2. When exposed to laser power several order of magnitude below their LIDT, the optical component lifetime is, by default, considered infinite. Under specific conditions, the accumulation of laser pulses may lead to a contamination of the surface and a degradation of its optical properties and LIDT. In the first order, these phenomena depend on the experimental conditions such as the irradiation time, the laser power, and the environment. In order to better understand the physics emphasizing this degradation, we developed an experimental cell with an in-situ spectroscopic ellipsometry diagnostic. The dry-pumped cell sheltering the sample is associated with a mass spectrometer that enables us to follow the environmental conditions in which we experiment the ageing. Anti-reflection coatings on fused silica were tested under 10 kHz-532 nm laser ageing. We present first results of degradation obtained in these conditions.

  6. High-speed stimulated Brillouin scattering spectroscopy at 780 nm

    NASA Astrophysics Data System (ADS)

    Remer, Itay; Bilenca, Alberto

    2016-09-01

    We demonstrate a high-speed stimulated Brillouin scattering (SBS) spectroscopy system that is able to acquire stimulated Brillouin gain point-spectra in water samples and Intralipid tissue phantoms over 2 GHz within 10 ms and 100 ms, respectively, showing a 10-100 fold increase in acquisition rates over current frequency-domain SBS spectrometers. This improvement was accomplished by integrating an ultra-narrowband hot rubidium-85 vapor notch filter in a simplified frequency-domain SBS spectrometer comprising nearly counter-propagating continuous-wave pump-probe light at 780 nm and conventional single-modulation lock-in detection. The optical notch filter significantly suppressed stray pump light, enabling detection of stimulated Brillouin gain spectra with substantially improved acquisition times at adequate signal-to-noise ratios (˜25 dB in water samples and ˜15 dB in tissue phantoms). These results represent an important step towards the use of SBS spectroscopy for high-speed measurements of Brillouin gain resonances in scattering and non-scattering samples.

  7. Arrays of 100 nm Magnetic Nanorings with High Areal Densities

    NASA Astrophysics Data System (ADS)

    Zhu, F. Q.; Fan, D. L.; Cammarata, R. C.; Zhu, X. C.; Zhu, J. G.; Chien, C. L.

    2004-03-01

    Arrays of magnetic nanorings with high areal densities have special attributes. To date only a small number of μ m-size rings have been made by lithography. Here we present a new lithography-less process for fabricating a large number of 100 nm Co nanorings over a macroscopic area with an extremely high areal density (45 rings/μ m^2). Hysteresis loops show two switching fields at about 150 Oe and 2 kOe. Micromagnetics simulations reveal two reversal processes. In the first process two domain walls in the onion state attract and annihilate to form a vortex state. The stable vortex state requires 2 kOe to induce two domain walls and form the reversed onion state. The second process with a switching field of about 50 Oe involves the rotation of the onion state by 180r with the two domain walls at the opposite ends. Both reversal processes exist simultaneously in our sample, and the hysteresis behavior is the superposition of two such hysteresis loops. Work supported by NSF and DARPA.

  8. Electrical control of antiferromagnetic metal up to 15 nm

    NASA Astrophysics Data System (ADS)

    Zhang, PengXiang; Yin, GuFan; Wang, YuYan; Cui, Bin; Pan, Feng; Song, Cheng

    2016-08-01

    Manipulation of antiferromagnetic (AFM) spins by electrical means is on great demand to develop the AFM spintronics with low power consumption. Here we report a reversible electrical control of antiferromagnetic moments of FeMn up to 15 nm, using an ionic liquid to exert a substantial electric-field effect. The manipulation is demonstrated by the modulation of exchange spring in [Co/Pt]/FeMn system, where AFM moments in FeMn pin the magnetization rotation of Co/Pt. By carrier injection or extraction, the magnetic anisotropy of the top layer in FeMn is modulated to influence the whole exchange spring and then passes its influence to the [Co/Pt]/FeMn interface, through a distance up to the length of exchange spring that fully screens electric field. Comparing FeMn to IrMn, despite the opposite dependence of exchange bias on gate voltages, the same correlation between carrier density and exchange spring stiffness is demonstrated. Besides the fundamental significance of modulating the spin structures in metallic AFM via all-electrical fashion, the present finding would advance the development of low-power-consumption AFM spintronics.

  9. Observations of thunderstorm-related 630 nm airglow depletions

    NASA Astrophysics Data System (ADS)

    Kendall, E. A.; Bhatt, A.

    2015-12-01

    The Midlatitude All-sky imaging Network for Geophysical Observations (MANGO) is an NSF-funded network of 630 nm all-sky imagers in the continental United States. MANGO will be used to observe the generation, propagation, and dissipation of medium and large-scale wave activity in the subauroral, mid and low-latitude thermosphere. This network is actively being deployed and will ultimately consist of nine all-sky imagers. These imagers form a network providing continuous coverage over the western United States, including California, Oregon, Washington, Utah, Arizona and Texas extending south into Mexico. This network sees high levels of both medium and large scale wave activity. Apart from the widely reported northeast to southwest propagating wave fronts resulting from the so called Perkins mechanism, this network observes wave fronts propagating to the west, north and northeast. At least three of these anomalous events have been associated with thunderstorm activity. Imager data has been correlated with both GPS data and data from the AIRS (Atmospheric Infrared Sounder) instrument on board NASA's Earth Observing System Aqua satellite. We will present a comprehensive analysis of these events and discuss the potential thunderstorm source mechanism.

  10. Maskless Plasmonic Lithography at 22 nm Resolution

    PubMed Central

    Pan, Liang; Park, Yongshik; Xiong, Yi; Ulin-Avila, Erick; Wang, Yuan; Zeng, Li; Xiong, Shaomin; Rho, Junsuk; Sun, Cheng; Bogy, David B.; Zhang, Xiang

    2011-01-01

    Optical imaging and photolithography promise broad applications in nano-electronics, metrologies, and single-molecule biology. Light diffraction however sets a fundamental limit on optical resolution, and it poses a critical challenge to the down-scaling of nano-scale manufacturing. Surface plasmons have been used to circumvent the diffraction limit as they have shorter wavelengths. However, this approach has a trade-off between resolution and energy efficiency that arises from the substantial momentum mismatch. Here we report a novel multi-stage scheme that is capable of efficiently compressing the optical energy at deep sub-wavelength scales through the progressive coupling of propagating surface plasmons (PSPs) and localized surface plasmons (LSPs). Combining this with airbearing surface technology, we demonstrate a plasmonic lithography with 22 nm half-pitch resolution at scanning speeds up to 10 m/s. This low-cost scheme has the potential of higher throughput than current photolithography, and it opens a new approach towards the next generation semiconductor manufacturing. PMID:22355690

  11. Domain wall motion in sub-100 nm magnetic wire

    NASA Astrophysics Data System (ADS)

    Siddiqui, Saima; Dutta, Sumit; Currivan, Jean Anne; Ross, Caroline; Baldo, Marc

    2015-03-01

    Nonvolatile memory devices such as racetrack memory rely on the manipulation of domain wall (DW) in magnetic nanowires, and scaling of these devices requires an understanding of domain wall behavior as a function of the wire width. Due to the increased importance of edge roughness and magnetostatic interaction, DW pinning increases dramatically as the wire dimensions decrease and stochastic behavior is expected depending on the distribution of pinning sites. We report on the field driven DW statistics in sub-100 nm wide nanowires made from Co films with very small edge roughness. The nanowires were patterned in the form of a set of concentric rings of 10 μm diameter. Two different width nanowires with two different spacings have been studied. The rings were first saturated in plane to produce onion states and then the DWs were translated in the wires using an orthogonal in-plane field. The position of the DWs in the nanowires was determined with magnetic force microscopy. From the positions of the DWs in the nanowires, the strength of the extrinsic pinning sites was identified and they follow two different distributions in two different types of nanowire rings. For the closely spaced wires, magnetostatic interactions led to correlated movement of DWs in neighboring wires. The implications of DW pinning and interaction in nanoscale DW devices will be discussed.

  12. Ion exclusion by sub-2-nm carbon nanotube pores

    PubMed Central

    Fornasiero, Francesco; Park, Hyung Gyu; Holt, Jason K.; Stadermann, Michael; Grigoropoulos, Costas P.; Noy, Aleksandr; Bakajin, Olgica

    2008-01-01

    Biological pores regulate the cellular traffic of a large variety of solutes, often with high selectivity and fast flow rates. These pores share several common structural features: the inner surface of the pore is frequently lined with hydrophobic residues, and the selectivity filter regions often contain charged functional groups. Hydrophobic, narrow-diameter carbon nanotubes can provide a simplified model of membrane channels by reproducing these critical features in a simpler and more robust platform. Previous studies demonstrated that carbon nanotube pores can support a water flux comparable to natural aquaporin channels. Here, we investigate ion transport through these pores using a sub-2-nm, aligned carbon nanotube membrane nanofluidic platform. To mimic the charged groups at the selectivity region, we introduce negatively charged groups at the opening of the carbon nanotubes by plasma treatment. Pressure-driven filtration experiments, coupled with capillary electrophoresis analysis of the permeate and feed, are used to quantify ion exclusion in these membranes as a function of solution ionic strength, pH, and ion valence. We show that carbon nanotube membranes exhibit significant ion exclusion that can be as high as 98% under certain conditions. Our results strongly support a Donnan-type rejection mechanism, dominated by electrostatic interactions between fixed membrane charges and mobile ions, whereas steric and hydrodynamic effects appear to be less important. PMID:18539773

  13. 980nm diode laser pump modules operating at high temperature

    NASA Astrophysics Data System (ADS)

    Campbell, Jenna; Semenic, Tadej; Leisher, Paul; Bhunia, Avijit; Mashanovitch, Milan; Renner, Daniel

    2016-03-01

    Existing thermal management technologies for diode laser pumps place a significant load on the size, weight and power consumption of High Power Solid State and Fiber Laser systems, thus making current laser systems very large, heavy, and inefficient in many important practical applications. This problem is being addressed by the team formed by Freedom Photonics and Teledyne Scientific through the development of novel high power laser chip array architectures that can operate with high efficiency when cooled with coolants at temperatures higher than 50 degrees Celsius and also the development of an advanced thermal management system for efficient heat extraction from the laser chip array. This paper will present experimental results for the optical, electrical and thermal characteristics of 980 nm diode laser pump modules operating effectively with liquid coolant at temperatures above 50 degrees Celsius, showing a very small change in performance as the operating temperature increases from 20 to 50 degrees Celsius. These pump modules can achieve output power of many Watts per array lasing element with an operating Wall-Plug-Efficiency (WPE) of >55% at elevated coolant temperatures. The paper will also discuss the technical approach that has enabled this high level of pump module performance and opportunities for further improvement.

  14. 10{times} reduction imaging at 13.4nm

    SciTech Connect

    Tichenor, D.A.; Kubiak, G.D.; Malinowski, M.E.

    1994-08-01

    A Schwarzschild imaging system has been designed to achieve 0.1 {mu}m resolution in a 0.4 mm diameter field of view when operated at a center wavelength of 13.4 nm. A decentered aperture is located on the convex primary resulting in an unobstructed numerical aperture of 0.08 and a corresponding depth of field of {plus_minus} 1 {mu}m. The Schwarzschild imaging objective is part of a five-reflection system containing the laser plasma source (LPS), condensing optics, turning mirror and reflection mask as shown in Figure 1. Extreme ultraviolet (EUV) radiation is generated by impinging a laser beam onto a copper target. The plasma source is driven by a Lambda Physik PLX 250 KrF excimer laser emitting 0.6 Joule, 20 ns pulses at a 200 Hz maximum repetition rate. Measurements of the source indicate that the full-width-half-maximum diameter is less than 100 {mu}m.

  15. Layout dependent effects analysis on 28nm process

    NASA Astrophysics Data System (ADS)

    Li, Helen; Zhang, Mealie; Wong, Waisum; Song, Huiyuan; Xu, Wei; Hurat, Philippe; Ding, Hua; Zhang, Yifan; Cote, Michel; Huang, Jason; Lai, Ya-ch

    2015-03-01

    Advanced process nodes introduce new variability effects due to increased density, new material, new device structures, and so forth. This creates more and stronger Layout Dependent effects (LDE), especially below 28nm. These effects such as WPE (Well Proximity Effect), PSE (Poly Spacing Effect) change the carrier mobility and threshold voltage and therefore make the device performances, such as Vth and Idsat, extremely layout dependent. In traditional flows, the impact of these changes can only be simulated after the block has been fully laid out, the design is LVS and DRC clean. It's too late in the design cycle and it increases the number of post-layout iteration. We collaborated to develop a method on an advanced process to embed several LDE sources into a LDE kit. We integrated this LDE kit in custom analog design environment, for LDE analysis at early design stage. These features allow circuit and layout designers to detect the variations caused by LDE, and to fix the weak points caused by LDE. In this paper, we will present this method and how it accelerates design convergence of advanced node custom analog designs by detecting early-on LDE hotspots on partial or fully placed layout, reporting contribution of each LDE component to help identify the root cause of LDE variation, and even providing fixing guidelines on how to modify the layout and to reduce the LDE impact.

  16. Effects of 810 nm laser on mouse primary cortical neurons

    NASA Astrophysics Data System (ADS)

    Kharkwal, Gitika B.; Sharma, Sulbha K.; Huang, Ying-Ying; De Taboada, Luis; McCarthy, Thomas; Hamblin, Michael R.

    2011-03-01

    In the past four decades numerous studies have reported the efficacy of low level light (laser) therapy (LLLT) as a treatment for diverse diseases and injuries. Recent studies have shown that LLLT can biomodulate processes in the central nervous system and has been extensively studied as a stroke treatment. However there is still a lack of knowledge on the effects of LLLT at the cellular level in neurons. The present study aimed to study the effect of 810 nm laser on several cellular processes in primary cortical neurons cultured from mouse embryonic brains. Neurons were irradiated with light dose of 0.03, 0.3, 3, 10 and 30 J/cm2 and intracellular levels of reactive oxygen species, nitric oxide and calcium were measured. The changes in mitochondrial function in response to light were studied in terms of adenosine triphosphate (ATP) and mitochondrial membrane potential (MMP). Light induced a significant increase in calcium, ATP and MMP at lower fluences and a decrease at higher fluence. ROS was induced significantly by light at all light doses. Nitric oxide levels also showed an increase on treatment with light. The results of the present study suggest that LLLT at lower fluences is capable of inducing mediators of cell signaling process which in turn may be responsible for the biomodulatory effects of the low level laser. At higher fluences beneficial mediators are reduced but potentially harmful mediators are increased thus offering an explanation for the biphasic dose response.

  17. Optical metrology solutions for 10nm films process control challenges

    NASA Astrophysics Data System (ADS)

    Mahendrakar, Sridhar; Vaid, Alok; Venkataraman, Kartik; Lenahan, Michael; Seipp, Steven; Fang, Fang; Saxena, Shweta; Hu, Dawei; Yoon, Nam Hee; Song, Da; Camp, Janay; Ren, Zhou

    2016-03-01

    Controlling thickness and composition of gate stack layers in logic and memory devices is critical to ensure transistor performance meets requirements, especially at 10nm node due to the 3-d geometry of devices and tight process budget. It has become necessary to measure and control each layer in the gate stack before and after dielectric and metal gate deposition sequences. A typical gate stack can have 5-7 layers including the interfacial layer, high-k dielectric, metal gate stack, work function layers, and cap layers. Similarly, PMOS channel strain is controlled using a graded SixGe1-x stack grown epitaxially over fins in the source/drain regions. This graded stack can have 2-4 layers of different thicknesses and Ge concentrations. This paper discusses the benefit of using spectroscopic ellipsometry with multiple angles of incidence to accurately and precisely determine the thickness of individual layers in critical gate layer stacks at various process steps on planar and grating surfaces. We will also show the benefit of using an advanced laser-based ellipsometer, for ultra-precise measurement of the gate interfacial layer oxides.

  18. Photodissociation dynamics of OCS near 214 nm using ion imaging.

    PubMed

    Wei, Wei; Wallace, Colin J; McBane, George C; North, Simon W

    2016-07-14

    The OCS photodissociation dynamics of the dominant S((1)D2) channel near 214 nm have been studied using velocity map ion imaging. We report a CO vibrational branching ratio of 0.79:0.21 for v = 0:v = 1, indicating substantially higher vibrational excitation than that observed at slightly longer wavelengths. The CO rotational distribution is bimodal for both v = 0 and v = 1, although the bimodality is less pronounced than at longer wavelengths. Vector correlations, including rotational alignment, indicate that absorption to both the 2(1)A' (A) and 1(1)A″ (B) states is important in the lower-j part of the rotational distribution, while only 2(1)A' state absorption contributes to the upper part; this conclusion is consistent with work at longer wavelengths. Classical trajectory calculations including surface hopping reproduce the measured CO rotational distributions and their dependence on wavelength well, though they underestimate the v = 1 population. The calculations indicate that the higher-j peak in the rotational distribution arises from molecules that begin on the 2(1)A' state but make nonadiabatic transitions to the 1(1)A' (X) state during the dissociation, while the lower-j peak arises from direct photodissociation on either the 2(1)A' or the 1(1)A″ states, as found in previous work. PMID:27421408

  19. [Application of Raman spectrometer (785 nm) to jadeite test].

    PubMed

    Fan, Jian-liang; Guo, Shou-guo; Liu, Xue-liang

    2007-10-01

    Jadeite is a greatly appreciated gemstone and often referred to as "the king of jade". Because of the advances in processing the treated jadeite is becoming more and more difficult for identification. NIR (785 nm) Raman spectrometer exhibits advantage of non-destruction, quickness, accurateness, and weak fluorescence interferences. This work reports such a research conducted using a NIR Raman spectrometer for a large number of jadeite samples. Based on the spectra collected and analysis there after performed, it is evident that the instrumentation and analysis methodology used have provided great information and assessment assistance in the application. It was found that the spectral response in the green area of a natural jadeite is much stronger in intensity than that in the white area. This is attributed to the key factor, the content of Cr3+ in the area. In contrast the spectral response in the green area of a treated jadeite is much weaker and additional Raman peaks start to show up on the high Raman shift side. This is the evidence of added fluorescence phenomenon and epoxyresin. It was also discovered that certain Raman features disappear compared to a natural sample. This indicates that the jadeite has been treated with acid and filled with colorless glue, which io turn destroyed the original exterior structure of a jadeite. PMID:18306795

  20. Advanced Write Tool Effects on 100-nm Node OPC

    NASA Astrophysics Data System (ADS)

    Buck, Peter D.; Green, Kent G.; Ibsen, Kent B.; Nakagawa, Kent H.; Hong, Dongsung; Krishnan, Prakash; Coburn, Dianna

    2002-12-01

    It has long been understood that there is an image fidelity difference between the integrated circuit design pattern and the photomask made from that pattern, largely due to the finite spot size of pattern generators. Furthermore, there are known differences in photomask image fidelity (rounding, jogs, etc.) between e-beam and laser pattern generators. Using a novel technique developed by DuPont Photomasks, Inc. (DPI), actual photomask fidelity has been simulated from design data to produce a more true-to-life representation of the mask. We have performed analytical simulations and printed-wafer measurements on Cypress 100-nm technology designs to determine the differences and effects on optical proximity correction (OPC) of two types of pattern generators: 50 keV e-beam and DUV laser. Both JEOL 9000MV-II+ and ETEC ALTA 4000 images were simulated and saved in GDSII format ("mask-GDSII"). These new mask images were processed through standard lithography simulation software to predict the effects each mask writer has on localized optical proximity effects. Simulations were compared to printed wafer results. A detailed comparison of the accuracy of the mask-GDSII and original design GDSII is performed. Furthermore, comparison of 50 keV e-beam and DUV laser image fidelity is completed, and recommendations are made on how to correct OPC models for each type of photomask generator. Lastly, conclusions are drawn about the use of DUV laser and 50 keV e-beam photomasks.