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Sample records for compact ariborne spectrographic

  1. Estuarine Landcover Along the Lower Columbia River Estuary Determined from Compact Ariborne Spectrographic Imager (CASI) Imagery, Technical Report 2003.

    SciTech Connect

    Garono, Ralph; Robinson, Rob

    2003-10-01

    Developing an understanding of the distribution and changes in estuarine and riparian habitats is critical to the management of biological resources in the lower Columbia River. In a recently completed comprehensive ecosystem protection and enhancement plan for the lower Columbia River Estuary (CRE), Jerrick (1999) identified habitat loss and modification as one of the key threats to the integrity of the CRE ecosystem. This management plan called for an inventory of habitats as key first step in the CRE long-term restoration effort. While previous studies have produced useful data sets depicting habitat cover types along portions of the lower CRE (Thomas, 1980; Thomas, 1983; Graves et al., 1995; NOAA, 1997; Allen, 1999), no single study has produced a description of the habitats for the entire CRE. Moreover, the previous studies differed in data sources and methodologies making it difficult to merge data or to make temporal comparisons. Therefore, the Lower Columbia River Estuary Partnership (Estuary Partnership) initiated a habitat cover mapping project in 2000. The goal of this project was to produce a data set depicting the current habitat cover types along the lower Columbia River, from its mouth to the Bonneville Dam, a distance of {approx}230-km (Fig. 1) using both established and emerging remote sensing techniques. For this project, we acquired two types of imagery, Landsat 7 ETM+ and Compact Airborne Spectrographic Imager (CASI). Landsat and CASI imagery differ in spatial and spectral resolution: the Landsat 7 ETM+ sensor collects reflectance data in seven spectral bands with a spatial resolution of 30-m and the CASI sensor collects reflectance data in 19 bands (in our study) with a spatial resolution of 1.5-m. We classified both sets of imagery and produced a spatially linked, hierarchical habitat data set for the entire CRE and its floodplain. Landsat 7 ETM+ classification results are presented in a separate report (Garono et al., 2003). This report

  2. Compact low resolution spectrograph, an imaging and long slit spectrograph for robotic telescopes

    SciTech Connect

    Rabaza, O.; Zeman, J.; Hudec, R.; Sabau-Graziati, L.

    2013-11-15

    The COmpact LOw REsolution Spectrograph (COLORES) is a compact and lightweight (13 kg) f/8 imaging spectrograph designed for robotic telescopes, now installed and operating on the TELMA, a rapid-slewing 60 cm telescope of the BOOTES-2 observatory in Málaga (Spain). COLORES is a multi-mode instrument that enables the observer to seamlessly switch between low-dispersion spectroscopy and direct imaging modes during an observation. In this paper, we describe the instrument and its development, from the initial scientific requirements through the optical design process to final configuration with theoretical performance calculations. The mechanical and electronic design is described, methods of calibration are discussed and early laboratory and scientific results are shown.

  3. Compact low resolution spectrograph, an imaging and long slit spectrograph for robotic telescopes

    NASA Astrophysics Data System (ADS)

    Rabaza, O.; Jelinek, M.; Castro-Tirado, A. J.; Cunniffe, R.; Zeman, J.; Hudec, R.; Sabau-Graziati, L.; Ruedas-Sánchez, J.

    2013-11-01

    The COmpact LOw REsolution Spectrograph (COLORES) is a compact and lightweight (13 kg) f/8 imaging spectrograph designed for robotic telescopes, now installed and operating on the TELMA, a rapid-slewing 60 cm telescope of the BOOTES-2 observatory in Málaga (Spain). COLORES is a multi-mode instrument that enables the observer to seamlessly switch between low-dispersion spectroscopy and direct imaging modes during an observation. In this paper, we describe the instrument and its development, from the initial scientific requirements through the optical design process to final configuration with theoretical performance calculations. The mechanical and electronic design is described, methods of calibration are discussed and early laboratory and scientific results are shown.

  4. Solar glint suppression in compact planetary ultraviolet spectrographs

    NASA Astrophysics Data System (ADS)

    Davis, Michael W.; Cook, Jason C.; Grava, Cesare; Greathouse, Thomas K.; Gladstone, G. Randall; Retherford, Kurt D.

    2015-08-01

    Solar glint suppression is an important consideration in the design of compact photon-counting ultraviolet spectrographs. Southwest Research Institute developed the Lyman Alpha Mapping Project for the Lunar Reconnaissance Orbiter (launch in 2009), and the Ultraviolet Spectrograph on Juno (Juno-UVS, launch in 2011). Both of these compact spectrographs revealed minor solar glints in flight that did not appear in pre-launch analyses. These glints only appeared when their respective spacecraft were operating outside primary science mission parameters. Post-facto scattered light analysis verifies the geometries at which these glints occurred and why they were not caught during ground testing or nominal mission operations. The limitations of standard baffle design at near-grazing angles are discussed, as well as the importance of including surface scatter properties in standard stray light analyses when determining solar keep-out efficiency. In particular, the scattered light analysis of these two instruments shows that standard "one bounce" assumptions in baffle design are not always enough to prevent scattered sunlight from reaching the instrument focal plane. Future builds, such as JUICE-UVS, will implement improved scattered and stray light modeling early in the design phase to enhance capabilities in extended mission science phases, as well as optimize solar keep out volume.

  5. Compact high-resolution spectrographs for large and extremely large telescopes: using the diffraction limit

    NASA Astrophysics Data System (ADS)

    Robertson, J. Gordon; Bland-Hawthorn, Joss

    2012-09-01

    As telescopes get larger, the size of a seeing-limited spectrograph for a given resolving power becomes larger also, and for ELTs the size will be so great that high resolution instruments of simple design will be infeasible. Solutions include adaptive optics (but not providing full correction for short wavelengths) or image slicers (which give feasible but still large instruments). Here we develop the solution proposed by Bland-Hawthorn and Horton: the use of diffraction-limited spectrographs which are compact even for high resolving power. Their use is made possible by the photonic lantern, which splits a multi-mode optical fiber into a number of single-mode fibers. We describe preliminary designs for such spectrographs, at a resolving power of R ~ 50,000. While they are small and use relatively simple optics, the challenges are to accommodate the longest possible fiber slit (hence maximum number of single-mode fibers in one spectrograph) and to accept the beam from each fiber at a focal ratio considerably faster than for most spectrograph collimators, while maintaining diffraction-limited imaging quality. It is possible to obtain excellent performance despite these challenges. We also briefly consider the number of such spectrographs required, which can be reduced by full or partial adaptive optics correction, and/or moving towards longer wavelengths.

  6. PIMMS échelle: the next generation of compact diffraction limited spectrographs for arbitrary input beams

    NASA Astrophysics Data System (ADS)

    Betters, Christopher H.; Leon-Saval, Sergio G.; Bland-Hawthorn, Joss; Richards, Samuel N.; Birks, Tim A.; Gris-Sánchez, Itandehui

    2014-07-01

    PIMMS échelle is an extension of previous PIMMS (photonic integrated multimode spectrograph) designs, enhanced by using an échelle diffraction grating as the primary dispersing element for increased spectral band- width. The spectrograph operates at visible wavelengths (550 to 780nm), and is capable of capturing ~100 nm of R > 60, 000 (λ/(triangle)λ) spectra in a single exposure. PIMMS échelle uses a photonic lantern to convert an arbitrary (e.g. incoherent) input beam into N diffraction-limited outputs (i.e. N single-mode fibres). This allows a truly diffraction limited spectral resolution, while also decoupling the spectrograph design from the input source. Here both the photonic lantern and the spectrograph slit are formed using a single length of multi-core fibre. A 1x19 (1 multi-mode fiber to 19 single-mode fibres) photonic lantern is formed by tapering one end of the multi-core fibre, while the other end is used to form a TIGER mode slit (i.e. for a hexagonal grid with sufficient spacing and the correct orientations, the cores of the multi-core fibre can be dispersed such that they do not overlap without additional reformatting). The result is an exceptionally compact, shoebox sized, spectrograph that is constructed primarily from commercial off the shelf components. Here we present a brief overview of the échelle spectrograph design, followed by results from on-sky testing of the breadboard mounted version of the spectrograph at the `UK Schmidt Telescope'.

  7. A compact soft X-ray spectrograph combining high efficiency and resolution

    NASA Astrophysics Data System (ADS)

    Fäustlin, R. R.; Zastrau, U.; Toleikis, S.; Uschmann, I.; Förster, E.; Tschentscher, Th

    2010-02-01

    A compact and light weight soft X-ray spectrograph covering 5-35 nm and employing a toroidal mirror and a variable line space reflection grating has been newly developed. Particular emphasis has been placed on achieving a large collection solid angle (1.9 × 10-3 sr) and a high efficiency of the components in order to enable Thomson Scattering plasma diagnostics which has a small total cross section (6.65 × 10-25 cm2). The instrument achieves a signal-to-noise ratio of 5 with a 13.5 nm source which isotropically emits 2.5 × 105 photons. A resolution λ/Δλ = 330 was measured at 21 nm and the dispersion was calibrated. The instrument is housed inside a DN 100 CF ultra high vacuum manipulator (43 × 46 × 47 cm3) which allows positioning relative to the source within ±5 mm and ±50 mm in X,Y and Z direction, respectively. It can be used with or without entrance pinhole and is equipped with a motorized grating, a filter wheel with five filters, and a shutter. Altogether, these features make the spectrograph a versatile instrument which can be employed in a variety of physics applications such as line and bremsstrahlung spectroscopy or Thomson scattering.

  8. [Estimating Leaf Area Index of Crops Based on Hyperspectral Compact Airborne Spectrographic Imager (CASI) Data].

    PubMed

    Tang, Jian-min; Liao, Qin-hong; Liu, Yi-qing; Yang, Gui-jun; Feng, Hai-kuanr; Wang, Ji-hua

    2015-05-01

    The fast estimation of leaf area index (LAI) is significant for learning the crops growth, monitoring the disease and insect, and assessing the yield of crops. This study used the hyperspectral compact airborne spectrographic imager (CASI) data of Zhangye city, in Heihe River basin, on July 7, 2012, and extracted the spectral reflectance accurately. The potential of broadband and red-edge vegetation index for estimating the LAI of crops was comparatively investigated by combined with the field measured data. On this basis, the sensitive wavebands for estimating the LAI of crops were selected and two new spectral indexes (NDSI and RSI) were constructed, subsequently, the spatial distribution of LAI in study area was analyzed. The result showed that broadband vegetation index NDVI had good effect for estimating the LAI when the vegetation coverage is relatively lower, the R2 and RMSE of estimation model were 0. 52, 0. 45 (p<0. 01) , respectively. For red-edge vegetation index, CIred edge took the different crop types into account fully, thus it gained the same estimation accuracy with NDVI. NDSI(569.00, 654.80) and RSI(597.60, 654.80) were constructed by using waveband combination algorithm, which has superior estimation results than NDVI and CIred edge. The R2 of estimation model used NDSI(569.00, 654.80) was 0. 77(p<0. 000 1), it mainly used the wavebands near the green peak and red valley of vegetation spectrum. The spatial distribution map of LAI was made according to the functional relationship between the NDSI(569.00, 654.80) and LAI. After analyzing this map, the LAI values were lower in the northwest of study area, this indicated that more fertilizer should be increased in this area. This study can provide technical support for the agricultural administrative department to learn the growth of crops quickly and make a suitable fertilization strategy. PMID:26415459

  9. Development of compact and ultra-high-resolution spectrograph with multi-GHz optical frequency comb

    NASA Astrophysics Data System (ADS)

    Endo, Mamoru; Sukegawa, Takashi; Silva, Alissa; Kobayashi, Yohei

    2014-08-01

    In recent years, a calibration method for an astronomical spectrograph using an optical frequency comb (OFC) with a repetition rate of more than ten GHz has been developed successfully [1-5]. But controlling filtering cavities that are used for thinning out longitudinal modes precludes long term stability. The super-mode noise coming from the fundamental repetition rate is an additional problem. We developed a laser-diode pumped Yb:Y2O3 ceramic oscillator, which enabled the generation of 4-GHz (maximum repetition rate of 6.7 GHz) pulse trains directly with a spectrum width of 7 nm (full-width half-maximum, FWHM), and controlled its optical frequency within a MHz level of accuracy using a beat note between the 4-GHz laser and a 246-MHz Yb-fiber OFC. The optical frequency of the Yb-fiber OFC was phase locked to a Rb clock frequency standard. Furthermore we also built a table-top multi-pass spectrograph with a maximum frequency resolution of 600 MHz and a bandwidth of 1 nm using a large-size high-efficiency transmission grating. The resolution could be changed by selecting the number of passes through the grating. This spectrograph could resolve each longitudinal mode of our 4-GHz OFC clearly, and more than 10% throughput was obtained when the resolution was set to 600 MHz. We believe that small and middle scale astronomical observatories could easily implement such an OFC-calibrated spectrograph.

  10. First Studies with the Compact Echelle Spectrograph for Aeronomical Research (CESAR)

    NASA Astrophysics Data System (ADS)

    Slanger, T. G.; Hedin, J.; Matsiev, D.

    2014-12-01

    The CESAR echelle spectrograph has been in operation at Poker Flat Research Range since November 2013. High-resolution spectra (R ~ 5000) of both the nightglow and the aurorae have been obtained, and the data overlap the time period in which measurements from the PINOT campaign were made. It has been of particular interest to search for regions in which the O2(b-X) Atmospheric band system could be studied with minimal interference from auroral N2/N2+ features. The b-X 2-1 band at 697 nm is such a feature. At longer wavelengths we have ascertained that CESAR is capable of making measurements on the N(2P-2D) lines near 1040 nm, an extremely strong multiplet where the wavelength region has prevented systematic measurements. Controversially, earlier studies had indicated that these lines suffered interference from the N2 First Positive 0-0 band, which we do not find in our limited sample.

  11. Design and performance of a new generation, compact, low cost, very high Doppler precision and resolution optical spectrograph

    NASA Astrophysics Data System (ADS)

    Ge, Jian; Zhao, Bo; Powell, Scott; Wang, Ji; Fletcher, Adam; Chang, Liang; Groot, John; Wan, Xiaoke; Jakeman, Hali; Myers, Derek; Grafer, Elliot; Liu, Jian; Varosi, Frank; Schofield, Sidney; Moore, Alexandria; van Olphen, Maria-Ines; Katz, Jordan; Barnes, Rory

    2012-09-01

    This paper is to report the design and performance of a very high Doppler precision cross-dispersed echelle spectrograph, EXtremely high Precision ExtrasolaR planet Tracker III (EXPERT-III), as part of a global Exoplanet Tracker (ET) network. The ET network is designed to hunt low mass planets, especially habitable rocky planets, around GKM dwarfs. It has an extremely high spectral resolution (EHR) mode of R=110,000 and a high resolution (HR) mode of R=56,000 and can simultaneously cover 0.38-0.9 μm with a 4kx4k back-illuminated Fairchild CCD detector with a single exposure. EXPERT-III is optimized for high throughput by using two-prisms cross-disperser and a large core diameter fiber (2 arcsec on sky, or 80 μm at f/4) to collect photons from the Kitt Peak National Observatory (KPNO) 2.1m telescope. The average overall detection efficiency is ~6% from above the atmosphere to the detector for the EHR Mode and about 11% for the HR mode. The extremely high spectral resolution in a compact design (the spectrograph dimension, 1.34x0.8x0.48 m) is realized by coupling the single input 80 μm telescope fiber into four 40 μm fibers and re-arranging the four small core diameter fibers into a linear fiber slit array (a one-to-four fiber image slicer). EXPERT-III is operated in a vacuum chamber with temperature controlled to ~2 milli-Kelvin rms for an extended period of time. The radial velocity (RV) drift is controlled to within 10 meters/second (m/s) over a month. EXPERT-III can reach a photon noise limited RV measurement precision of ~0.3 m/s for a V=8 mag GKM type dwarf with small rotation (vsini =2 km/s) in a 15 min exposure. EXPERT-III's RV measurement uncertainties for bright stars are primarily limited by the Thorium-Argon (ThAr) calibration source (~0.5 m/s). EXPERT-III will serve as an excellent public accessible high resolution optical spectroscope facility at the KPNO 2.1m telescope.

  12. A robotic, compact, and extremely high resolution optical spectrograph for a close-in super-Earth survey

    NASA Astrophysics Data System (ADS)

    Ge, Jian; Powell, Scott; Zhao, Bo; Varosi, Frank; Ma, Bo; Sithajan, Sirinrat; Liu, Jian; Li, Rui; Grieves, Nolan; Schofield, Sidney; Avner, Louis; Jakeman, Hali; Yoder, William A.; Gittelmacher, Jakob A.; Singer, Michael A.; Muterspaugh, Matthew; Williamson, Michael; Maxwell, J. E.

    2014-08-01

    One of the most astonishing results from the HARPS and Kepler planet surveys is the recent discovery of close-in super-Earths orbiting more than half of FGKM dwarfs. This new population of exoplanets represents the most dominant class of planetary systems known to date, is totally unpredicted by the classical core-accretion disk planet formation model. High cadence and high precision Doppler spectroscopy is the key to characterize properties of this new population and constrain planet formation models. A new robotic, compact high resolution optical spectrograph, called TOU (formerly called EXPERT-III), was commissioned at the Automatic Spectroscopic Telescope (AST) at Fairborn Observatory in Arizona in July 2013 and has produced a spectral resolution of about 100,000 and simultaneous wavelength coverage of 0.38-0.9 μm with a 4kx4k back-illuminated Fairchild CCD detector. The instrument holds a very high vacuum of 1 micro torr and about 2 mK temperature stability over a month. The early on-sky RV measurements show that this instrument is approaching a Doppler precision of 1 m/s (rms) for bright reference stars (such as Tau Ceti) with 5 min exposures and better than 3 m/s (P-V, RMS~1 m/s) daily RV stability before calibration exposures are applied. A pilot survey of 20 V<9 FGK dwarfs, including known super-Earth systems and known RV stable stars, is being launched and every star will be observed ~100 times over ~300 days time window between this summer and next spring, following up with a full survey of ~150 V< 10 FGKM dwarfs in 2015-2017.

  13. Spitzer/infrared spectrograph investigation of mipsgal 24 μm compact bubbles: low-resolution observations

    SciTech Connect

    Nowak, M.; Flagey, N.; Noriega-Crespo, A.; Carey, S. J.; Van Dyk, S. D.; Billot, N.; Paladini, R.

    2014-12-01

    We present Spitzer/InfraRed Spectrograph (IRS) low-resolution observations of 11 compact circumstellar bubbles from the MIPSGAL 24 μm Galactic plane survey. We find that this set of MIPSGAL bubbles (MBs) is divided into two categories and that this distinction correlates with the morphologies of the MBs in the mid-infrared (IR). The four MBs with central sources in the mid-IR exhibit dust-rich, low-excitation spectra, and their 24 μm emission is accounted for by the dust continuum. The seven MBs without central sources in the mid-IR have spectra dominated by high-excitation gas lines (e.g., [O IV] 26.0 μm, [Ne V] 14.3 and 24.3 μm, and [Ne III] 15.5 μm), and the [O IV] line accounts for 50% to almost 100% of the 24 μm emission in five of them. In the dust-poor MBs, the [Ne V] and [Ne III] line ratios correspond to high-excitation conditions. Based on comparisons with published IRS spectra, we suggest that the dust-poor MBs are highly excited planetary nebulae (PNs) with peculiar white dwarfs (e.g., Wolf-Rayet [WR] and novae) at their centers. The central stars of the four dust-rich MBs are all massive star candidates. Dust temperatures range from 40 to 100 K in the outer shells. We constrain the extinction along the lines of sight from the IRS spectra. We then derive distance, dust masses, and dust production rate estimates for these objects. These estimates are all consistent with the nature of the central stars. We summarize the identifications of MBs made to date and discuss the correlation between their mid-IR morphologies and natures. Candidate Be/B[e]/luminous blue variable and WR stars are mainly 'rings' with mid-IR central sources, whereas PNs are mostly 'disks' without mid-IR central sources. Therefore we expect that most of the 300 remaining unidentified MBs will be classified as PNs.

  14. Evaluation of a compact spectrograph/detection system for a LIBS instrument for in-situ and stand-off detection

    SciTech Connect

    Salle B.; Cremers, D. A.; Benelli, K. M.; Busse, J. R.; Wiens, R. C.; Maurice, S.; Walters, R. A.

    2004-01-01

    Laser-induced breakdown spectroscopy (LIBS) is a method of determining the elemental composition of a material at in-situ or stand-off distances. The information content of the plasma is high. For this reason, LIBS is being developed for instruments to planet surfaces. Each laser plasma generates a light signal containing a high density of information regarding the elemental components of the target material. The useful spectral range of the emitted light extends from the vacuum ultraviolet ({approx} 120 nm) out to 850 nm. Within these extreme are strong emission features from all elements useful to identify the element in the target and also to perform quantitative analysis. The detection system (spectrograph and detector) used to process the plasma light determine sthe quality and quantity of the data gathered. The processing of the collected plasma light by the spectrograph and detector includes (1) spectral dispersion of the light, (2) recording the spectrally resolved light signal and (3) converting the photonic information to digital form. The characteristics of these two components are crucial to the performance of a LIBS instrument. Spectrographs and detection systems being considered by us for a LIBS flight instrument include a very compact grating type spectrograph integrated in a single package with a CCD detector. An example is the commercially-available Ocean Optics HR2000 spectrograph. This system provides spectral coverage over a fixed limited range with a certain spectral resolution. For such a system, the trade off is between spectral coverage and resolution. Additional units may be used, however, to monitor simultaneously other spectral ranges. A second type of detection system under consideration is an echelle spectrography with a 2-dimensional array detector. Inherently, this system provides complete spectral coverage with the resolution being determined by the size of the spectrography and pixel spacing of the detector array. Both systems are

  15. Field Raman spectrograph for environmental analysis

    SciTech Connect

    Haas, J.W. III; Forney, R.W.; Carrabba, M.M.

    1995-10-01

    This project entails the development of a compact raman spectrograph for field screening and monitoring of a wide variety of wastes, pollutants, and corrosion products in tanks, and environmental materials. The design of a fiber optic probe for use with the spectrograph is also discussed.

  16. Designing Echelle Spectrographs

    NASA Technical Reports Server (NTRS)

    Dantzler, A.

    1987-01-01

    Performance numbers and output maps computed from inputs supplied by user. Echelle Spectrograph Design Aid program (EGRAM) aids in design of spectrographic systems that utilize echelle/first-order crossdisperser combinations. Optical combination causes two-dimensional echellogram to fall on detector. Describes echellogram with enough detail to enable user to judge effectively feasibility of spectrograph design. By iteratively altering system parameters, desired echellogram achieved without making physical model. Calculates system parameters accurately to first order and compare favorably to results from raytracing techniques. EGRAM written in two versions. FORTRAN 77, and Microsoft BASIC A.

  17. MUSE: feeding and mounting 24 spectrographs

    NASA Astrophysics Data System (ADS)

    Nicklas, Harald; Seifert, Walter; Xu, Wenli; Hofmann, Denni; Köhler, Christof; Loupias, Magali

    2008-07-01

    The Multi Unit Spectroscopic Explorer MUSE is an integral field device containing 24 spectrographs at the Nasmyth focus of the VLT unit telescope. The total field size of 1'x1' needs to be split and separated into 24 sub-fields which are relayed along a central structure into the entrance aperture of the individual spectrographs. The realization of the optics for field splitting and separation as well as the relay optics to direct the light of the individual fields to the spectrographs is described here. A very tight link exists between the relay optics system layout and the mechanical arrangement of the spectrographs in the common central structure. A compact mounting is essential due to the restricted space for such a large instrument even on the VLT Nasmyth platform. A suitable arrangement of vertical and horizontal stacking of the spectrographs was found enabling their feeding from the unobstructed front side of the instrumental structure. The central instrument mount was designed as a stiff structure absorbing print-through effects due to thermal mismatch with the telescope platform but rigid enough to withstand earthquakes.

  18. PRISM Spectrograph Optical Design

    NASA Technical Reports Server (NTRS)

    Chipman, Russell A.

    1995-01-01

    The objective of this contract is to explore optical design concepts for the PRISM spectrograph and produce a preliminary optical design. An exciting optical configuration has been developed which will allow both wavelength bands to be imaged onto the same detector array. At present the optical design is only partially complete because PRISM will require a fairly elaborate optical system to meet its specification for throughput (area*solid angle). The most complex part of the design, the spectrograph camera, is complete, providing proof of principle that a feasible design is attainable. This camera requires 3 aspheric mirrors to fit inside the 20x60 cm cross-section package. A complete design with reduced throughput (1/9th) has been prepared. The design documents the optical configuration concept. A suitable dispersing prism material, CdTe, has been identified for the prism spectrograph, after a comparison of many materials.

  19. Immersion echelle spectrograph

    DOEpatents

    Stevens, Charles G.; Thomas, Norman L.

    2000-01-01

    A small spectrograph containing no moving components and capable of providing high resolution spectra of the mid-infrared region from 2 microns to 4 microns in wavelength. The resolving power of the spectrograph exceeds 20,000 throughout this region and at an optical throughput of about 10.sup.-5 cm.sup.2 sr. The spectrograph incorporates a silicon immersion echelle grating operating in high spectral order combined with a first order transmission grating in a cross-dispersing configuration to provide a two-dimensional (2-D) spectral format that is focused onto a two-dimensional infrared detector array. The spectrometer incorporates a common collimating and condensing lens assembly in a near aberration-free axially symmetric design. The spectrometer has wide use potential in addition to general research, such as monitoring atmospheric constituents for air quality, climate change, global warming, as well as monitoring exhaust fumes for smog sources or exhaust plumes for evidence of illicit drug manufacture.

  20. Single Mode, Extreme Precision Doppler Spectrographs

    NASA Astrophysics Data System (ADS)

    Schwab, Christian; Leon-Saval, Sergio G.; Betters, Christopher H.; Bland-Hawthorn, Joss; Mahadevan, Suvrath

    2014-04-01

    The `holy grail' of exoplanet research today is the detection of an earth-like planet: a rocky planet in the habitable zone around a main-sequence star. Extremely precise Doppler spectroscopy is an indispensable tool to find and characterize earth-like planets; however, to find these planets around solar-type stars, we need nearly one order of magnitude better radial velocity (RV) precision than the best current spectrographs provide. Recent developments in astrophotonics (Bland-Hawthorn & Horton 2006, Bland-Hawthorn et al. 2010) and adaptive optics (AO) enable single mode fiber (SMF) fed, high resolution spectrographs, which can realize the next step in precision. SMF feeds have intrinsic advantages over multimode fiber or slit coupled spectrographs: The intensity distribution at the fiber exit is extremely stable, and as a result the line spread function of a well-designed spectrograph is fully decoupled from input coupling conditions, like guiding or seeing variations (Ihle et al. 2010). Modal noise, a limiting factor in current multimode fiber fed instruments (Baudrand & Walker 2001), can be eliminated by proper design, and the diffraction limited input to the spectrograph allows for very compact instrument designs, which provide excellent optomechanical stability. A SMF is the ideal interface for new, very precise wavelength calibrators, like laser frequency combs (Steinmetz et al. 2008, Osterman et al. 2012), or SMF based Fabry-Perot Etalons (Halverson et al. 2013). At near infrared wavelengths, these technologies are ready to be implemented in on-sky instruments, or already in use. We discuss a novel concept for such a spectrograph.

  1. Kyoto Tridimensional Spectrograph II

    NASA Astrophysics Data System (ADS)

    Sugai, Hajime; Ohtani, Hiroshi; Ishigaki, Tsuyoshi; Hayashi, Tadashi; Ozaki, Shinobu; Hattori, Takashi; Ishii, M.; Sasaki, Minoru; Takeyama, Norihide

    1998-07-01

    We are building the second version of the Kyoto Tridimensional Spectrograph (Ohtani et al., this symposium). This will be mounted on the MAGNUM, a 2-m telescope under construction at Haleakala, and also on the SUBARU. The spectrograph has four observational modes: Fabry-Perot imager, integral field spectrograph (IFS) with a microlens array, long-slit spectrograph, and filter-imaging modes. The new spectrograph is significantly better than the first version in several ways. The IFS has as many as 37 X 37 microlenses, each of which subtends 0' .39 at the MAGNUM. The optics is designed to be used in wide wavelength ranges from 360 nm to 900 nm. The transmission at any wavelength between 370 and 900 nm is designed to exceed 50% for the collimator plus camera system, and to reach almost 40% even at 360 nm. In order to achieve high efficiency at short wavelengths, we use an anti- reflection coated backside-illuminated 2K X 2K CCD. We are also planning a further improvement by using multi-layer anti- reflection coatings for lenses, in collaboration with National Astronomical Observatory, Japan. In order to assure good image quality under a severe weight limit of 150 kg for this instrument, we have carried out mechanical design by calculating the flexure of the instrument for all telescope attitudes with finite element analysis, and succeeded in limiting the maximum flexure to 30 micrometer. This does not degrade image quality. The movements on the CCD of the light from the center of the focal plane have also been simulated, depending on the telescope attitudes. This is important to obtain not only a good image, but also a correct flat field and wavelength calibration in the IFS mode. The movements are expected to be confined almost within one pixel for an attitude, which is considered to be small enough.

  2. CEOI microslice spectrograph

    NASA Astrophysics Data System (ADS)

    Content, Robert; Blake, Simon; Dunlop, Colin; Nandi, David; Sharples, Ray; Talbot, Gordon; Shanks, Tom; Donoghue, Danny; Galiatsatos, Nikolaos; Luke, Peter

    2012-09-01

    We developed the technology of microslice integral field units some years ago as the next step in SAURON type microlens IFU design with typically 5 times more spatial elements (spaxels) for the same spectrograph and spectral length aiming at 1,000,000 spaxels IFUs. A full instrument for laboratory demonstration composed of the fore-optics, the IFU, the spectrograph and the detector has now been built and tested. It has about 10,000 spatial elements and spectra 150 pixel long. Our IFU has 5 cylindrical microlens arrays along the optical axis as opposed to one hexagonal array in the previous design. Instead of imaging pupils on the spectrograph input focal plane, our IFU images short slitlets 17 pixel long that keep the spatial information along the spatial direction then giving 17 spaxels per slitlet instead of one in pupil imaging. This removes most of the lost space between spectra leaving place for more and keeps the spatial information over the element size while pupil images lose it. The fore-optics re-images the field on the input of the IFU. They are made of cylindrical optics to get the desired different magnifications in both directions. All the optics and detector fit in a cylinder 35 mm in diameter and 280 mm long. With a different set of fore-optics on a 4-m telescope, a field of 43" x 6.7" with spatial elements of 0.14" x 0.22" could be observed so 12 of these mini-spectrographs would cover a field surface area of about 1 arcmin2 and 120,000 spaxels.

  3. Immersion echelle spectrograph

    SciTech Connect

    Stevens, C.G.; Thomas, N.L.

    2000-06-20

    A small spectrograph is disclosed containing no moving components and capable of providing high resolution spectra of the mid-infrared region from 2 microns to 4 microns in wavelength. The resolving power of the spectrograph exceeds 20,000 throughout this region and at an optical throughput of about 10{sup {minus}5}cm{sup 2}sr. The spectrograph incorporates a silicon immersion echelle grating operating in high spectral order combined with a first order transmission grating in a cross-dispersing configuration to provide a two-dimensional (2-D) spectral format that is focused onto a two-dimensional infrared detector array. The spectrometer incorporates a common collimating and condensing lens assembly in a near aberration-free axially symmetric design. The spectrometer has wide use potential in addition to general research, such as monitoring atmospheric constituents for air quality, climate change, global warming, as well as monitoring exhaust fumes for smog sources or exhaust plumes for evidence of illicit drug manufacture.

  4. THE COSMIC ORIGINS SPECTROGRAPH

    SciTech Connect

    Green, James C.; Michael Shull, J.; Snow, Theodore P.; Stocke, John; Froning, Cynthia S.; Osterman, Steve; Beland, Stephane; Burgh, Eric B.; Danforth, Charles; France, Kevin; Ebbets, Dennis; Heap, Sara H.; Leitherer, Claus; Sembach, Kenneth; Linsky, Jeffrey L.; Savage, Blair D.; Siegmund, Oswald H. W.; Spencer, John; Alan Stern, S.; Welsh, Barry; and others

    2012-01-01

    The Cosmic Origins Spectrograph (COS) is a moderate-resolution spectrograph with unprecedented sensitivity that was installed into the Hubble Space Telescope (HST) in 2009 May, during HST Servicing Mission 4 (STS-125). We present the design philosophy and summarize the key characteristics of the instrument that will be of interest to potential observers. For faint targets, with flux F{sub {lambda}} Almost-Equal-To 1.0 Multiplication-Sign 10{sup -14} erg cm{sup -2} s{sup -1} A{sup -1}, COS can achieve comparable signal to noise (when compared to Space Telescope Imaging Spectrograph echelle modes) in 1%-2% of the observing time. This has led to a significant increase in the total data volume and data quality available to the community. For example, in the first 20 months of science operation (2009 September-2011 June) the cumulative redshift pathlength of extragalactic sight lines sampled by COS is nine times than sampled at moderate resolution in 19 previous years of Hubble observations. COS programs have observed 214 distinct lines of sight suitable for study of the intergalactic medium as of 2011 June. COS has measured, for the first time with high reliability, broad Ly{alpha} absorbers and Ne VIII in the intergalactic medium, and observed the He II reionization epoch along multiple sightlines. COS has detected the first CO emission and absorption in the UV spectra of low-mass circumstellar disks at the epoch of giant planet formation, and detected multiple ionization states of metals in extra-solar planetary atmospheres. In the coming years, COS will continue its census of intergalactic gas, probe galactic and cosmic structure, and explore physics in our solar system and Galaxy.

  5. A new mass spectrograph.

    PubMed

    Matsuo, T; Ishihara, M

    1993-05-01

    The optical designs of two new types of mass spectrographs were studied. The first is a system that possesses a specially shaped magnet output boundary to satisfy the double-focusing condition for a wide mass range. The focal plane is usually curved. The second system is one in which a parallel ion beam is generated before the magnet, forming a straight double-focusing line. By introducing a quadrupole lens doublet such that the ion beam may be deflected in the same direction through the electric and magnetic fields, the overall image magnification can be arbitrarily controlled and stigmatic focusing achieved for the median ray. PMID:24234934

  6. A Spectrograph for BigBOSS

    NASA Astrophysics Data System (ADS)

    CARTON, Pierre-Henri; Bebek, C.; Cazaux, S.; Ealet, A.; Eppelle, D.; Kneib, J.; Karst, P.; levi, M.; magneville, C.; Palanque-Delabrouille, N.; Ruhlmann-Kleider, V.; Schlegel, D.; Yeche, C.

    2012-01-01

    The Big-Boss spectrographs assembly will take in charge the light from the fiber output to the detector, including the optics, gratings, mechanics and cryostats. The 5000 fibers are split in 10 bundles of 500 ones. Each of these channel feed one spectrograph. The full bandwidth from 0.36µm to 1.05µm is split in 3 bands. Each channel is composed with one collimator (doublet lenses), a VPH grating, and a 6 lenses camera. The 500 fiber spectrum are imaged onto a 4kx4k detector thanks to the F/2 camera. Each fiber core is imaged onto 4 pixels. Each channel of the BigBOSS spectrograph will be equipped with a single-CCD camera, resulting in 30 cryostats in total for the instrument. Based on its experience of CCD cameras for projects like EROS and MegaCam, CEA/Saclay has designed small and autonomous cryogenic vessels which integrate cryo-cooling, CCD positioning and slow control interfacing capabilities. The use of a Linear Pulse Tube with its own control unit, both developed by Thales Cryogenics BV, will ensure versatility, reliability and operational flexibility. CCD's will be cooled down to 140K, with stability better than 1K. CCD's will be positioned within 15µm along the optical axis and 50µm in the XY Plan. Slow Control machines will be directly interfaced to an Ethernet network, which will allow them to be operated remotely. The concept of spectrograph leads to a very robust concept without any mechanics (except the shutters). This 30 channels has a impressive compactness with its 3m3 volume. The development of such number of channel will drive to a quasi mass production philosophy.

  7. The Robotic FLOYDS Spectrographs

    NASA Astrophysics Data System (ADS)

    Sand, D.

    I will discuss the twin FLOYDS robotic spectrographs, operating at the 2m Faulkes Telescopes North and South. The FLOYDS instruments were designed with supernova classification and monitoring in mind, with a very large wavelength coverage (˜320 to 1000 nm) and a resolution (R ˜ 300 - 500, wavelength dependent) well-matched to the broad features of these and other transient and time domain events. Robotic acquisition of spectroscopic targets is the key ingredient for making robotic spectroscopy possible, and FLOYDS uses a slit-viewing camera with a ˜ 4‧ × 6‧ field to either do direct world coordinate system fitting or standard blind offsets to automatically place science targets into the slit. Future work includes an 'all-electronic' target of opportunity mode, which will allow for fast transient spectroscopy with no human necessary, even for inputting information into a phase 2 GUI. Initial science highlights from FLOYDS will also be presented.

  8. Spectrographic imaging system

    DOEpatents

    Morris, Michael D.; Treado, Patrick J.

    1991-01-01

    An imaging system for providing spectrographically resolved images. The system incorporates a one-dimensional spatial encoding mask which enables an image to be projected onto a two-dimensional image detector after spectral dispersion of the image. The dimension of the image which is lost due to spectral dispersion on the two-dimensional detector is recovered through employing a reverse transform based on presenting a multiplicity of different spatial encoding patterns to the image. The system is especially adapted for detecting Raman scattering of monochromatic light transmitted through or reflected from physical samples. Preferably, spatial encoding is achieved through the use of Hadamard mask which selectively transmits or blocks portions of the image from the sample being evaluated.

  9. The Cosmic Origins Spectrograph

    NASA Technical Reports Server (NTRS)

    Green, James C.; Froning, Cynthia S.; Osterman, Steve; Ebbets, Dennis; Heap, Sara H.; Leitherer, Claus; Linsky, Jeffrey L.; Savage, Blair D.; Sembach, Kenneth; Shull, J. Michael; Siegmund, Oswald H. W.; Snow, Theodore P.; Spencer, John; Stern, S. Alan; Stocke, John; Welsh, Barry; Beland, Stephane; Burgh, Eric B.; Danforth, Charles; France, Kevin; Keeney, Brian; McPhate, Jason; Penton, Steven V; Andrews, John; Morse, Jon

    2010-01-01

    The Cosmic Origins Spectrograph (COS) is a moderate-resolution spectrograph with unprecedented sensitivity that was installed into the Hubble Space Telescope (HST) in May 2009, during HST Servicing Mission 4 (STS-125). We present the design philosophy and summarize the key characteristics of the instrument that will be of interest to potential observers. For faint targets, with flux F(sub lambda) approximates 1.0 X 10(exp -14) ergs/s/cm2/Angstrom, COS can achieve comparable signal to noise (when compared to STIS echelle modes) in 1-2% of the observing time. This has led to a significant increase in the total data volume and data quality available to the community. For example, in the first 20 months of science operation (September 2009 - June 2011) the cumulative redshift pathlength of extragalactic sight lines sampled by COS is 9 times that sampled at moderate resolution in 19 previous years of Hubble observations. COS programs have observed 214 distinct lines of sight suitable for study of the intergalactic medium as of June 2011. COS has measured, for the first time with high reliability, broad Lya absorbers and Ne VIII in the intergalactic medium, and observed the HeII reionization epoch along multiple sightlines. COS has detected the first CO emission and absorption in the UV spectra of low-mass circumstellar disks at the epoch of giant planet formation, and detected multiple ionization states of metals in extra-solar planetary atmospheres. In the coming years, COS will continue its census of intergalactic gas, probe galactic and cosmic structure, and explore physics in our solar system and Galaxy.

  10. Echelle spectrograph software design aid

    NASA Technical Reports Server (NTRS)

    Dantzler, A. A.

    1985-01-01

    A method for mapping, to first order, the spectrograms that result from echelle spectrographic systems is discussed. An in-depth description of the principles behind the method are given so that software may be generated. Such software is an invaluable echelle spectrograph design aid. Results from two applications are discussed.

  11. Interferometric resolution boosting for spectrographs

    SciTech Connect

    Erskine, D J; Edelstein, J

    2004-05-25

    Externally dispersed interferometry (EDI) is a technique for enhancing the performance of spectrographs for wide bandwidth high resolution spectroscopy and Doppler radial velocimetry. By placing a small angle-independent interferometer near the slit of a spectrograph, periodic fiducials are embedded on the recorded spectrum. The multiplication of the stellar spectrum times the sinusoidal fiducial net creates a moir{acute e} pattern, which manifests high detailed spectral information heterodyned down to detectably low spatial frequencies. The latter can more accurately survive the blurring, distortions and CCD Nyquist limitations of the spectrograph. Hence lower resolution spectrographs can be used to perform high resolution spectroscopy and radial velocimetry. Previous demonstrations of {approx}2.5x resolution boost used an interferometer having a single fixed delay. We report new data indicating {approx}6x Gaussian resolution boost (140,000 from a spectrograph with 25,000 native resolving power), taken by using multiple exposures at widely different interferometer delays.

  12. Efficiently mating fibers to spectrographs

    NASA Astrophysics Data System (ADS)

    Brodie, Jean P.; Donnelly, R. H.; Epps, Harland W.; Radovan, Matthew V.; Craig, William W.

    1994-06-01

    We describe the conversion of an existing f/8 Cassegrain spectrograph to a floor-mounted spectrograph fed by 94 fibers from the f/5 prime focus of the Shane 3-meter telescope at Lick Observatory. The spectrography forms part of the automated Multi- Object Spectrograph system developed as a collaboration between UCO/Lick Observatory and the Lawrence Livermore National Laboratory. Fibers from a robotic fiber-positioner at prime focus degrade the f/5.5 beam from the telescope (after it has passed through a wide-field prime focus corrector) into roughly a f/4.5 beam. If the 4/8 spectrograph were fed directly with this f/4.5 beam approximately 68% of the light would be lost. A simple optical system has been designed that converts the light from the fibers into the f/ratio expected by the spectrograph. The conversion optics are mounted at the entrance to the spectrograph. We describe focal ratio degradation tests of a variety of optical fibers and the design of the `pseudoslit' which mounts the fibers in a line at the input to the conversion optics.

  13. Near ultraviolet spectrograph for balloon platform

    NASA Astrophysics Data System (ADS)

    Sreejith, A. G.; Safonova, Margarita; Murthy, Jayant

    2015-06-01

    Small and compact scientific payloads may be easily designed constructed and own on high altitude balloons. Despite the fact that large orbital observatories provide accurate observations and statistical studies of remote and/or faint space sources, small telescopes on board balloons or rockets are still attractive because of their low cost and rapid response time. We describe here a near ultraviolet (NUV) spectrograph designed to be own on a high{altitude balloon platform. Our basic optical design is a modified Czerny-Turner system using off the shelf optics. We compare different methods of aberration corrections in such a system. We intend the system to be portable and scalable to different telescopes. The use of reflecting optics reduces the transmission loss in UV. We plan on using an image intensified CMOS sensor operating in photon counting mode as the detector of choice.

  14. Field Raman spectrograph for environmental analysis

    SciTech Connect

    Haas, J.W. III; Forney, R.W.; Carrabba, M.M.; Rauh, R.D.

    1995-12-01

    The enormous cost for chemical analysis at DOE facilities predicates that cost-saving measures be implemented. Many approaches, ranging from increasing laboratory sample throughput by reducing preparation time to the development of field instrumentation, are being explored to meet this need. Because of the presence of radioactive materials at many DOE sites, there is also a need for methods that are safer for site personnel and analysts. This project entails the development of a compact Raman spectrograph for field screening and monitoring of a wide variety of wastes, pollutants, and corrosion products in storage tanks, soils, and ground and surface waters. Analytical advantages of the Raman technique include its ability to produce a unique, spectral fingerprint for each contaminant and its ability to analyze both solids and liquids directly, without the need for isolation or cleanup.

  15. Extreme luminosity imaging conical spectrograph

    SciTech Connect

    Pikuz, S. A.; Shelkovenko, T. A.; Mitchell, M. D.; Chandler, K. M.; Douglass, J. D.; McBride, R. D.; Jackson, D. P.; Hammer, D. A.

    2006-10-15

    A new configuration for a two-dimensional (2D) imaging x-ray spectrograph based on a conically bent crystal is introduced: extreme luminosity imaging conical spectrograph (ELICS). The ELICS configuration has important advantages over spectrographs that are based on cylindrically and spherically bent crystals. The main advantages are that a wide variety of large-aperture crystals can be used, and any desired magnification in the spatial direction (the direction orthogonal to spectral dispersion) can be achieved by the use of different experimental arrangements. The ELICS can be set up so that the detector plane is almost perpendicular to the incident rays, a good configuration for time-resolved spectroscopy. ELICSs with mica crystals of 45x90 mm{sup 2} aperture have been successfully used for imaging on the XP and COBRA pulsed power generators, yielding spectra with spatial resolution in 2D of Z pinches and X pinches.

  16. MMT and Magellan infrared spectrograph

    NASA Astrophysics Data System (ADS)

    McLeod, Brian A.; Fabricant, Daniel; Geary, John; Martini, Paul; Nystrom, George; Elston, Richard; Eikenberry, Stephen S.; Epps, Harland

    2004-09-01

    We present the preliminary design for the MMT and Magellan Infrared Spectrograph (MMIRS). MMIRS is a fully refractive imager and multi-object spectrograph that uses a 2048x2048 pixel Hawaii2 HgCdTe array. It offers a 7'x7' imaging field of view and a 4'x7' field of view for multi-object spectroscopy. Dispersion is provided by a set of 5 grisms providing R=3000 at J, H, or K, or R=1300 in J+H or H+K.

  17. X-ray spectrograph design

    NASA Technical Reports Server (NTRS)

    Chrisp, M. P.

    1983-01-01

    An aberration theory is applied to spectrograph design. The initial system considered has a toroidal mirror in front of a concave grating spectrograph, giving spatial resolution perpendicular to the dispersion direction. The accuracy of the theory is shown by comparison of spot diagrams obtained from the aberrations with those produced by raytracing. The major aberrations affecting the vignetting at the intermediate slit and the spatial resolution are identified. A new system, using a holographic grating to give a flat focal plane, is then designed and optimized. It has increased spatial resolution over the wavelength range and is particularly suitable for microchannel array detectors.

  18. Kyoto tridimensional spectrograph II: progress

    NASA Astrophysics Data System (ADS)

    Sugai, Hajime; Ohtani, Hiroshi; Ozaki, Shinobu; Hattori, Takashi; Ishii, Motomi; Ishigaki, Tsuyoshi; Hayashi, Tadashi; Sasaki, Minoru; Takeyama, Norihide

    2000-08-01

    We are building the Kyoto tridimensional spectrograph II and are planning to mount it on Subaru telescope. The spectrograph has four observational modes: Fabry-Perot imager, integral field spectrograph (IFS) with a microlens array, long-slit spectrograph, and filter-imaging modes. The optics is designed to be used in wide wavelength range from 360 nm to 900 nm. The design well matches with high spatial resolution of Subaru: 0 inch .06 pixel-1 in Fabry- Perot mode, for which we actually will use binning before adaptive optics at optical wavelengths becomes available, and 0 inch .1 lens-1 in microlens array mode. These well sample image sizes obtained by Subaru, which are about 0 inch .4 in relatively good conditions. We have evaluated a point spread function of our cylindrical microlens array and found that it consists of a diffraction pattern and more extended component which probably comes from border regions between microlenses. With a suitable mask at the micro pupil position, the crosstalk between spectra will be limited down to a few percent. With a suitable mask at the micro pupil position, the crosstalk between spectra will be limited down to a few percent. We have succeeded in synchronizing frequency switching of Fabry-Perot etalons with the movement of charge on the CCD. This technique enables to average out all temporal variations between each passband.

  19. Holographic spectrograph for space telescope

    NASA Astrophysics Data System (ADS)

    Ditto, Thomas D.; Lysenko, Sergiy; Crenshaw, Melissa

    2013-09-01

    A spectrograph is described which is made with dual Holographic Optical Elements (HOEs) which are identical and parallel to each other. Both optics are collimating transmission HOEs with focal points that are at equal and opposite distances from each other. The identical HOEs are formed by the interference of a plane wave parallel to the grating plane with an off-axis spherical wave originating in the near-field. In playback, a spectrum can be formed from a point source radiator placed at the position of the recording spherical wave. If played back at an arbitrary wavelength other than the recording wavelength, the image exhibits coma. This spectrograph is intended for an unusual configuration where many nearly monochromatic sources of known wavelengths are separately positioned relative to the first HOE. The special application is in a space telescope capable of resolving spectra from habitable planets within 10 pc. HOEs of this type could be fabricated on membrane substrates with a low areal mass and stowable on rolls for insertion into the second Lagrange point. The intended application is for a 50 x 10 meter class primary objective holographic space telescope with 50 x 10 m HOEs in the spectrograph. We present a computer model of the spectrograph.. Experimental results are compared with predictions from theory. A single HOE is shown to perform over a wider bandwidth and is demonstrated.

  20. AVES: an adaptive optics visual echelle spectrograph for the VLT

    NASA Astrophysics Data System (ADS)

    Pasquini, Luca; Delabre, Bernard; Avila, Gerardo; Bonaccini, Domenico

    1998-07-01

    We present the preliminary study of a low cost, high performance spectrograph for the VLT, for observations in the V, R and I bands. This spectrograph is meant for intermediate (R equals 16,000) resolution spectroscopy of faint (sky and/or detector limited) sources, with particular emphasis on the study of solar-type (F-G) stars belonging to the nearest galaxies and to distant (or highly reddened) galactic clusters. The spectrograph is designed to use the adaptive optics (AO) systems at the VLT Telescope. Even if these AO systems will not provide diffraction limited images in the V, R and I bands, the photon concentration will still be above approximately 60% of the flux in an 0.3 arcsecond aperture for typical Paranal conditions. This makes the construction of a compact, cheap and efficient echelle spectrograph possible. AVES will outperform comparable non adaptive optic instruments by more than one magnitude for sky- and/or detector-limited observations, and it will be very suitable for observations in crowded fields.

  1. Faint Object Spectrograph (FOS) calibration

    NASA Technical Reports Server (NTRS)

    Harms, R. J.; Beaver, E. A.; Burbidge, E. M.; Angel, J. R. P.; Bartko, F.; Mccoy, J.; Ripp, L.; Bohlin, R.; Davidsen, A. F.; Ford, H.

    1982-01-01

    The Faint Object Spectrograph (FOS) designed for use with The Space Telescope (ST), is currently preparing for instrument assembly, integration, alignment, and calibration. Nearly all optical and detector elements have been completed and calibrated, and selection of flight detectors and all but a few optical elements has been made. Calibration results for the flight detectors and optics are presented, and plans for forthcoming system calibration are briefly described.

  2. Structure of the spectrograph ESOPO

    NASA Astrophysics Data System (ADS)

    Sierra, G.; Farah, A.; Gonzalez, J.; Pedrayes, M.; Arroyo, M.; Avila, G.; Cobos, F.; Colorado, E.; Córdova, A.; Costero, R.; Chapa, O.; Echevarria, J.; García, B.; Garfias, F.; Guisa, G.; Granados, F.; Luna, E.; Martínez, B.; Michel, R.; Murillo, F.; Murillo, J.; Quechol, S.; Quiroz, F.; Tejada, C.

    2008-07-01

    The structure of the spectrograph ESOPO is the stiff mount that will maintain fixed all optics elements, electronics and mechanical subsystems. The ESOPO spectrograph is a project of the "Instituto de Astronomia de la Universidad Nacional Autonoma de Mexico" (IAUNAM) to upgrade its 2.1m telescope as a competitive facility for the next decade. The scientific purpose is to obtain a modern high efficient intermediate-low dispersion spectrograph optimized for the 3500 - 9000 Å spectral interval with a spectral resolution of 500 <= R <= 5000. It is to be used at the cassegrain f/7.5 focus of the 2.1 m telescope for general astronomical purposes. This work presents the mechanical design process and the form in which the structure was verified to comply with the ESOPO's top level image quality and stability requirements. The latter was not a lineal process. The way we resolved it is to run FEAs on the complete system and with the instrument in different operation positions during a normal cycle of observations. These results are validated through the error budget of the ESOPO. The structure is currently under construction.

  3. EGRAM- ECHELLE SPECTROGRAPH DESIGN AID

    NASA Technical Reports Server (NTRS)

    Dantzler, A. A.

    1994-01-01

    EGRAM aids in the design of spectrographic systems that utilize an echelle-first order cross disperser combination. This optical combination causes a two dimensional echellogram to fall on a detector. EGRAM describes the echellogram with enough detail to allow the user to effectively judge the feasibility of the spectrograph's design. By iteratively altering system parameters, the desired echellogram can be achieved without making a physical model. EGRAM calculates system parameters which are accurate to the first order and compare favorably to results from ray tracing techniques. The spectrographic system modelled by EGRAM consists of an entrance aperture, collimator, echelle, cross dispersion grating, focusing options, and a detector. The system is assumed to be free of aberrations and the echelle, cross disperser, and detector should be planar. The EGRAM program is menu driven and has a HELP facility. The user is prompted for information such as minimum and maximum wavelengths, slit dimensions, ruling frequencies, detector geometry, and angle of incidence. EGRAM calculates the resolving power and range of order numbers covered by the echellogram. A numerical map is also produced. This tabulates the order number, slit bandpass, and high/middle/low wavelengths. EGRAM can also compute the centroid coordinates of a specific wavelength and order (or vice versa). EGRAM is written for interactive execution and is written in Microsoft BASIC A. It has been implemented on an IBM PC series computer operating under DOS. EGRAM was developed in 1985.

  4. KIDSpec: an MKID based medium resolution integral field spectrograph

    NASA Astrophysics Data System (ADS)

    O'Brien, Kieran; Thatte, Niranjan; Mazin, Benjamin

    2014-07-01

    We present a novel concept for a highly sensitive, medium spectral resolution optical through near-IR spectrograph. KIDSpec, the Kinetic Inductance Detector Spectrograph, uses the intrinsic energy resolving capability of an array of optical/IR-sensitive MKIDs to distinguish multiple orders from a low line-density (echelle) grating. MKID arrays have a wide bandpass (0.1-2.5um) and good quantum efficiency, making them strong candidates for replacing CCDs in many astronomical instruments. By acting as an `order resolver', the MKID array replaces the cross-disperser in an echelle spectrograph. This greatly simplifies the optical layout of the spectrograph and enables longer slits than are possible with cross-dispersed instruments. KIDSpec would have similar capabilities to ESO's X-shooter instrument. It would provide an R=4000-10,000 spectrum covering the entire optical and near-IR spectral range. In addition to a `long-slit' mode, the IFU would provide a small (~50 spaxel) field-of-view for spatially resolved sources. In addition, the photon-counting operation of MKIDs and their photon-energy resolving ability enable a read-noise free spectrum with perfect cosmic ray removal. The spectral resolution would be sufficient to remove the bright night-sky lines without the additional pixel noise, making the instrument more sensitive than an equivalent semiconductor-based instrument. KIDSpec would enhance many existing high-profile science cases, including transient (GRB, SNe, etc.) follow-up, redshift determination of faint objects and transit spectroscopy of exoplanets. In addition it will enable unique science cases, such as dynamical mass estimates of the compact objects in ultra-compact binaries.

  5. Compact, Miniature MMIC Receiver Modules for an MMIC Array Spectrograph

    NASA Technical Reports Server (NTRS)

    Kangaslahti, Pekka P.; Gaier, Todd C.; Cooperrider, Joelle T.; Samoska, Lorene A.; Soria, Mary M.; ODwyer, Ian J.; Weinreb, Sander; Custodero, Brian; Owen, Heahter; Grainge, Keith; Church, Sarah; Lai, Richard; Mei, Xiaobing

    2009-01-01

    A single-pixel prototype of a W-band detector module with a digital back-end was developed to serve as a building block for large focal-plane arrays of monolithic millimeter-wave integrated circuit (MMIC) detectors. The module uses low-noise amplifiers, diode-based mixers, and a WR10 waveguide input with a coaxial local oscillator. State-of-the-art InP HEMT (high electron mobility transistor) MMIC amplifiers at the front end provide approximately 40 dB of gain. The measured noise temperature of the module, at an ambient temperature of 300 K, was found to be as low as 450 K at 95 GHz. The modules will be used to develop multiple instruments for astrophysics radio telescopes, both on the ground and in space. The prototype is being used by Stanford University to characterize noise performance at cryogenic temperatures. The goal is to achieve a 30-50 K noise temperature around 90 GHz when cooled to a 20 K ambient temperature. Further developments include characterization of the IF in-phase (I) and quadrature (Q) signals as a function of frequency to check amplitude and phase; replacing the InP low-noise amplifiers with state-of-the-art 35-nm-gate-length NGC low-noise amplifiers; interfacing the front-end module with a digital back-end spectrometer; and developing a scheme for local oscillator and IF distribution in a future array. While this MMIC is being developed for use in radio astronomy, it has the potential for use in other industries. Applications include automotive radar (both transmitters and receivers), communication links, radar systems for collision avoidance, production monitors, ground-penetrating sensors, and wireless personal networks.

  6. Airborne spectrograph for the thermal IR: Broadband Array Spectrograph System

    NASA Technical Reports Server (NTRS)

    Russell, Ray W.; Hackwell, John; Lynch, David; Mazuk, Ann

    1995-01-01

    Spectroscopic studies in the 'fingerprint' region of the thermal IR from 3 to 14 microns of celestial dust components and the overall energy distribution of the sources are best served by moderate spectral resolution (R = lambda/Delta lambda approximately 30 to 200), high sensitivity observations. Spectral purity and the reproducibility of the spectral shape are critical as well, when using the spectral shape to assign temperatures to dust grains or to gas clouds based on the wavelength and shape of molecular bands. These sensor attributes are also important to the use of wavelengths and ratios of solid state features to derive compositions of dust grains in celestial sources. The advent of high quality linear arrays of blocked impurity band (BIB) detectors of Si:As permitted the development of a state-of-the-art, patented, cooled prism spectrograph. Developed at The Aerospace Corporation largely with in-house funds, the Broadband Array Spectrograph System (BASS) has been used for a variety of remote sensing applications, but especially for IR astronomical studies on the Kuiper Airborne Observatory and at the NASA Infrared Telescope Facility (IRTF). The attributes of the spectrograph, specifically having the pupil imaged onto the 2 linear 58 element detector arrays so that the effects of guiding errors are minimized, being able to maximally exploit the limited observing time by acquiring all 116 spectral channels simultaneously, and having all spectral channels imaged through the same aperture so that spectral mapping is readily and reliably accomplished, afford the scientist with a unique opportunity to conduct both surveys of examples of many different types of sources as well as in-depth studies of a given class of object by thoroughly sampling the class members. This duality was demonstrated with the BASS through a combination of KAO flights where spectral maps were obtained as part of in-depth studies of specific source regions (such as Orion and W3) and

  7. Sky subtraction with fiber spectrographs

    NASA Astrophysics Data System (ADS)

    Lissandrini, C.; Cristiani, S.; La Franca, F.

    1994-11-01

    The sky-subtraction performance of multifiber spectrographs is discussed, analyzing in detail the case of the OPTOPUS system at the 3.6-m European Space Observatory (ESO) telescope at La Silla. A standard technique, based on flat fields obtained with a uniformly illuminated screen on the dome, provides poor results. A new method has been developed, using the (O I) emission line at 5577 A as a calibrator of the fiber transmittance, taking into account the diffuse light and the influence of each fiber on the adjacent ones, and correcting for the effects of the image distortions on the sky sampling. In this way the accuracy of the sky subtraction improves from 2%-8% to 1.3%-1.6%.

  8. Wide range magnetic electron spectrograph

    NASA Technical Reports Server (NTRS)

    Coplan, M. A.; Wang, L.-J.; Moore, J. H.; Hoffman, R. A.

    1989-01-01

    An electron spectrogrpah is described that covers electron energies from 400 eV to 200 keV with an energy resolution of 10 percent. This overlaps the range of electrostatic deflection devices at low energy and solid state detectors at high energy. The spectrograph uses magnetic deflection of the electrons to achieve energy separation and images the full range of energies on a single plane. The magnetic circuit uses the fringing field of two axially located magnets to attain the large energy range. Six separate electron beams can be dispersed in the field, each entering the circuit from a different angle. This is a particular advantage when measuring plasma electron three-dimensional velocity distributions. The angular response of the instrument is particularly favorable and the stray magnetic field is sufficiently low to meet spacecraft requirements.

  9. Ultraviolet-visible spectrograph optics: ODIN project

    NASA Astrophysics Data System (ADS)

    Powell, Ian; Bewsher, Amanda

    1995-10-01

    We describe one of the possible designs for the UV-visible spectrograph optics to be employed in the ODIN project. The spectrograph will be used in a future satellite mission for aeronomy observations and will image a column of atmosphere just above the Earth's surface onto a two-dimensional CCD array with the spatial and spectral content aligned orthogonal to one another.

  10. Photonic Spectrograph for new Technology Telescope (PSTT)

    NASA Astrophysics Data System (ADS)

    Jones, H. R. A.; PSTT Colaboration

    We outline a high stability precision infrared spectrograph intended for the New Technology Telescope at ESO's La Silla Observatory. This spectrograph known as PSTT (Photonic Spectrograph for new Technology Telescope) is intended to incorporate a number of new technologies that have recently become available, e.g., reformatting photonic lanterns, broadband laser combs and 4k2 infrared arrays. Elements such as OH suppression and an integrated photonic spectrograph should also be considered. The intention is to deliver a high resolution infrared spectrograph that can deliver sub-m/s radial velocity precision to the ESO community. This will enable the opportunity to discover and characterise Earth-mass planets around nearby objects as well as follow-up on results from transit surveys from the ground and space.

  11. High-resolving mass spectrographs and spectrometers

    NASA Astrophysics Data System (ADS)

    Wollnik, Hermann

    2015-11-01

    Discussed are different types of high resolving mass spectrographs and spectrometers. In detail outlined are (1) magnetic and electric sector field mass spectrographs, which are the oldest systems, (2) Penning Trap mass spectrographs and spectrometers, which have achieved very high mass-resolving powers, but are technically demanding (3) time-of-flight mass spectrographs using high energy ions passing through accelerator rings, which have also achieved very high mass-resolving powers and are equally technically demanding, (4) linear time-of-flight mass spectrographs, which have become the most versatile mass analyzers for low energy ions, while the even higher performing multi-pass systems have only started to be used, (5) orbitraps, which also have achieved remarkably high mass-resolving powers for low energy ions.

  12. Panchromatic spectrograph with supporting monochromatic imagers

    NASA Technical Reports Server (NTRS)

    Broadfoot, A. L.; Sandel, B. R.; Knecht, D.; Viereck, R.; Murad, E.

    1992-01-01

    The Arizona Imager/Spectrograph is a set of imaging spectrographs and 2D imagers for space flight. Nine nearly identical spectrographs record wavelengths from 114 to 1090 nm with a resolution of 0.5-1.3 nm. The spatial resolution along the slit is electronically selectable and can reach 192 elements. Twelve passband imagers cover wavelengths in the 160-900-nm range and have fields of view from 2 to 21 deg. The spectrographs and imagers rely on intensified CCD detectors to achieve substantial capability in an instrument of minimum mass and size. By use of innovative coupling techniques only two CCDs are required to record images from 12 imagers, and single CCDs record spectra from pairs of spectrographs. The fields of view of the spectrographs and imagers are coaligned, and all spectra and images can be exposed simultaneously. A scan platform can rotate the sensor head about two orthogonal axes. The Arizona imager/spectrograph is designed for investigations of the interaction between the Space Shuttle and its environment. It is scheduled for flight on a Shuttle subsatellite.

  13. The Schmidt-Czerny-Turner spectrograph

    NASA Astrophysics Data System (ADS)

    McClure, Jason P.

    2014-09-01

    Since the invention of the CCD detector in 1969 by George Smith and Willard Boyle, incremental innovations to the dispersive imaging spectrograph have slowly materialized in response the abounding advances in CCD detector technology. The modern Czerny-Turner type spectrograph, arguably the most commonly used instrument in optical spectroscopy, fails to uphold the ever increasing needs today's researchers demand, let alone tomorrow's. This paper discusses an innovative solution to the Czerny-Turner imaging spectrograph bridging a more than 20 year gap in development and understanding. A manifold of techniques in optical spectroscopy both advantaged and enabled by this innovation are expounded upon.

  14. NRES: The Network of Robotic Echelle Spectrographs

    NASA Astrophysics Data System (ADS)

    Siverd, Robert; Eastman, Jason D.; Brown, Timothy M.; Hygelund, John; Henderson, Todd; Tufts, Joseph; Van Eyken, Julian C.; Barnes, Stuart

    2015-01-01

    Las Cumbres Observatory Global Network (LCOGT) is building the Network of Robotic Echelle Spectrographs (NRES), which will consist of six identical, optical (390 - 860 nm) high-precision spectrographs, each fiber-fed simultaneously by two 1 meter telescopes and a thorium argon calibration source, one at each of our observatory sites in the Northern and Southern hemispheres. Thus, NRES will be a single, globally-distributed, autonomous observing facility using twelve 1-m telescopes. Simulations suggest we will achieve long-term radial velocity precision of better than 3 m/s in less than an hour for stars brighter than V = 12. We have been funded with NSF MRI and ATI grants, and expect our first spectrograph to be deployed in mid 2015, with the full network operation of all 6 units beginning in 2016. We will discuss the NRES design, goals, robotic operation, and status, as well as the early results from our prototype spectrograph.

  15. MEGARA: a new generation optical spectrograph for GTC

    NASA Astrophysics Data System (ADS)

    Gil de Paz, A.; Gallego, J.; Carrasco, E.; Iglesias-Páramo, J.; Cedazo, R.; Vílchez, J. M.; García-Vargas, M. L.; Arrillaga, X.; Carrera, M. A.; Castillo-Morales, A.; Castillo-Domínguez, E.; Eliche-Moral, M. C.; Ferrusca, D.; González-Guardia, E.; Lefort, B.; Maldonado, M.; Marino, R. A.; Martínez-Delgado, I.; Morales Durán, I.; Mujica, E.; Páez, G.; Pascual, S.; Pérez-Calpena, A.; Sánchez-Penim, A.; Sánchez-Blanco, E.; Tulloch, S.; Velázquez, M.; Zamorano, J.; Aguerri, A. L.; Barrado y Naváscues, D.; Bertone, E.; Cardiel, N.; Cava, A.; Cenarro, J.; Chávez, M.; García, M.; Guichard, J.; Gúzman, R.; Herrero, A.; Huélamo, N.; Hughes, D.; Jiménez-Vicente, J.; Kehrig, C.; Márquez, I.; Masegosa, J.; Mayya, Y. D.; Méndez-Abreu, J.; Mollá, M.; Muñoz-Tuñón, C.; Peimbert, M.; Pérez-González, P. G.; Pérez Montero, E.; Rodríguez, M.; Rodríguez-Espinosa, J. M.; Rodríguez-Merino, L.; Rosa-González, D.; Sánchez-Almeida, J.; Sánchez Contreras, C.; Sánchez-Blázquez, P.; Sánchez Moreno, F. M.; Sánchez, S. F.; Sarajedini, A.; Serena, F.; Silich, S.; Simón-Díaz, S.; Tenorio-Tagle, G.; Terlevich, E.; Terlevich, R.; Torres-Peimbert, S.; Trujillo, I.; Tsamis, Y.; Vega, O.; Villar, V.

    2014-07-01

    MEGARA (Multi-Espectrógrafo en GTC de Alta Resolución para Astronomía) is an optical Integral-Field Unit (IFU) and Multi-Object Spectrograph (MOS) designed for the GTC 10.4m telescope in La Palma. MEGARA offers two IFU fiber bundles, one covering 12.5x11.3 arcsec2 with a spaxel size of 0.62 arcsec (Large Compact Bundle; LCB) and another one covering 8.5x6.7 arcsec2 with a spaxel size of 0.42 arcsec (Small Compact Bundle; SCB). The MEGARA MOS mode will allow observing up to 100 objects in a region of 3.5x3.5 arcmin2 around the two IFU bundles. Both the LCB IFU and MOS capabilities of MEGARA will provide intermediate-to-high spectral resolutions (RFWHM~6,000, 12,000 and 18,700, respectively for the low-, mid- and high-resolution Volume Phase Holographic gratings) in the range 3650-9700ÅÅ. These values become RFWHM~7,000, 13,500, and 21,500 when the SCB is used. A mechanism placed at the pseudo-slit position allows exchanging the three observing modes and also acts as focusing mechanism. The spectrograph is a collimator-camera system that has a total of 11 VPHs simultaneously available (out of the 18 VPHs designed and being built) that are placed in the pupil by means of a wheel and an insertion mechanism. The custom-made cryostat hosts an E2V231-84 4kx4k CCD. The UCM (Spain) leads the MEGARA Consortium that also includes INAOE (Mexico), IAA-CSIC (Spain), and UPM (Spain). MEGARA is being developed under a contract between GRANTECAN and UCM. The detailed design, construction and AIV phases are now funded and the instrument should be delivered to GTC before the end of 2016.

  16. A spectrograph instrument concept for the Prime Focus Spectrograph (PFS) on Subaru Telescope

    NASA Astrophysics Data System (ADS)

    Vivès, Sébastien; Le Mignant, David; Madec, Fabrice; Jaquet, Marc; Prieto, Eric; Martin, Laurent; Le Fèvre, Olivier; Gunn, James; Carr, Michael; Smee, Stephen; Barkhouser, Robert; Sugai, Hajime; Tamura, Naoyuki

    2012-09-01

    We describe the conceptual design of the spectrograph opto-mechanical concept for the SuMIRe Prime Focus Spectrograph (PFS) being developed for the SUBARU telescope. The SuMIRe PFS will consist of four identical spectrographs, each receiving 600 fibers from a 2400 fiber robotic positioner at the prime focus. Each spectrograph will have three channels covering in total, a wavelength range from 380 nm to 1300 nm. The requirements for the instrument are summarized in Section 1. We present the optical design and the optical performance and analysis in Section 2. Section 3 introduces the mechanical design, its requirements and the proposed concepts. Finally, the AIT phases for the Spectrograph System are described in Section 5.

  17. NRES: The Network of Robotic Echelle Spectrographs

    NASA Astrophysics Data System (ADS)

    Siverd, Robert; Brown, Timothy M.; Hygelund, John; Henderson, Todd; Tufts, Joseph; Eastman, Jason; Van Eyken, Julian C.; Barnes, Stuart

    2016-01-01

    Las Cumbres Observatory Global Network (LCOGT) is building the Network of Robotic Echelle Spectrographs (NRES), which will consist of six identical, optical (390 - 860 nm) high-precision spectrographs, each fiber-fed simultaneously by up to two 1-meter telescopes and a thorium argon calibration source. We plan to install one at up to 6 observatory sites in the Northern and Southern hemispheres, creating a single, globally-distributed, autonomous spectrograph facility using up to twelve 1-m telescopes. Simulations suggest we will achieve long-term radial velocity precision of 3 m/s in less than an hour for stars brighter than V = 12. We have been funded with NSF MRI and ATI grants, and expect our first spectrograph to be deployed in early 2016, with the full network operation of 5 or 6 units beginning in 2017. We will briefly overview the NRES design, goals, robotic operation, and status. In addition, we will discuss early results from our prototype spectrograph, the laboratory and on-sky performance of our first production unit, and the ongoing software development effort to bring this resource online.

  18. NRES: The Network of Robotic Echelle Spectrographs

    NASA Astrophysics Data System (ADS)

    Siverd, Robert; Brown, Timothy M.; Henderson, Todd; Hygelund, John; Tufts, Joseph; Eastman, Jason; Barnes, Stuart; Van Eyken, Julian C.

    2016-06-01

    Las Cumbres Observatory Global Network (LCOGT) is building the Network of Robotic Echelle Spectrographs (NRES), which will consist of six identical, optical (390 - 860 nm) high-precision spectrographs, each fiber-fed simultaneously by up to two 1-meter telescopes and a thorium argon calibration source. We plan to install one at up to 6 observatory sites in the Northern and Southern hemispheres, creating a single, globally-distributed, autonomous spectrograph facility using up to twelve 1-m telescopes. Simulations suggest we will achieve long-term radial velocity precision of 3 m/s in less than an hour for stars brighter than V = 12. We have been funded with NSF MRI and ATI grants, and expect to deploy the first spectrograph in fall 2016, with the full network operation of 5 or 6 units beginning in 2017. We will briefly overview the NRES design, goals, robotic operation, and status. In addition, we will discuss early results from our prototype spectrograph, the laboratory and on-sky performance of our first production unit, initial science results, and the ongoing software development effort to bring this resource online.

  19. An Ultraviolet Imaging Spectrograph for JIMO

    NASA Technical Reports Server (NTRS)

    Hendrix, A. R.; Esposito, L. W.; Pryor, W. R.; Stewart, A. I. F.; McClintock, W. E.; Hansen, C. J.

    2003-01-01

    It is vital to include an ultraviolet spectrograph as part of the JIMO payload to Europa, Ganymede and Callisto. Ultraviolet measurements are key for understanding the atmospheres, auroral activity and surfaces of these icy satellites, and a UV imaging spectrograph will also complement a visible camera and near-IR spectrometer, to achieve full wavelength coverage in remote sensing of the icy satellites. The UV instrument proposed for JIMO will be similar to that currently on board the Cassini spacecraft. The design draws on the experience of building UV spectrometers for Mariner, Pioneer, Galileo and Cassini. It will have three spectrographic channels that provide images and spectra of the atmosphere, aurorae and surface: An EUV channel (800-110 nm), an FUV channel (110 to 190 nm) range, and an NUV channel (180 to 350 nm).

  20. Curved VPH gratings for novel spectrographs

    NASA Astrophysics Data System (ADS)

    Clemens, J. Christopher; O'Donoghue, Darragh; Dunlap, Bart H.

    2014-07-01

    The introduction of volume phase holographic (VPH) gratings into astronomy over a decade ago opened new possibilities for instrument designers. In this paper we describe an extension of VPH grating technology that will have applications in astronomy and beyond: curved VPH gratings. These devices can disperse light while simultaneously correcting aberrations. We have designed and manufactured two different kinds of convex VPH grating prototypes for use in off-axis reflecting spectrographs. One type functions in transmission and the other in reflection, enabling Offnerstyle spectrographs with the high-efficiency and low-cost advantages of VPH gratings. We will discuss the design process and the tools required for modelling these gratings along with the recording layout and process steps required to fabricate them. We will present performance data for the first convex VPH grating produced for an astronomical spectrograph.

  1. Thermal gradient analysis for the ESOPO spectrograph

    NASA Astrophysics Data System (ADS)

    Farah, A.; González, J. Jesús; Sierra, G.; Hernández, J. V.; Pedrayes, M.; Echevarría, J.; Costero, R.; Avila, G.; Arroyo, M.; Cobos, F.; Colorado, E.; Cordova, A.; Chapa, O.; Garcia, B.; Garfias, F.; Granados, F.; Guisa, G.; Luna, E.; Martínez, B.; Michel, R.; Murillo, F.; Pérez, F.; Quechol, S.; Quirós, F.; Tejada, C.

    2008-07-01

    ESOPO will be a spectrograph of medium resolution for the 2.1 m telescope of the National Observatory at San Pedro Martir, Baja California, Mexico. It has been developed by the Instituto de Astronomia of the Universidad Nacional Autonoma de Mexico (IA-UNAM). The main goal of this instrument is to modernize the capabilities of making science with that particular telescope. It is planned to achieve a spectral resolution between 500 and 5000. ESOPO is split into two arms; each one specialized in a specific wavelength range covering together all the visible light. A very important issue in spectrographs is to avoid inside thermal gradients. Different temperatures in the optical elements produce mechanical movements and image quality degradation during an exposition. The error budget analysis developed for ESOPO allows establishing the required limits for temperature gradients. In this paper is described the thermal analysis of the spectrograph, including specifications, finite element models, thermal equations and expected thermal gradients.

  2. National Student Solar Spectrograph Competition overview

    NASA Astrophysics Data System (ADS)

    Larimer, Randal M.; DesJardins, Angela; Shaw, Joseph A.; Kankelborg, Charles C.; Palmer, Christopher; Springer, Larry; Key, Joey; Knighton, W. Berk; Repasky, Kevin S.; Pust, Nathan J.; Hobish, Mitchell K.; Wilson, Edmond W.; Fitzgerald, Carrie; Fitzgerald, Ryan; Trickel, Thomas; Jensen, Clyde; Dorsett, Skye; Anderson, Matt; Boger, Jim; McCrady, Nate; Naylor, Jaylene; Battle, Laurie

    2012-10-01

    The yearly National Student Solar Spectrograph Competition (NSSSC) is Montana Space Grant Consortium's Education and Public Outreach (EP/O) Program for NASA's Interface Region Imaging Spectrograph (IRIS) mission. The NSSSC is designed to give schools with less aerospace activity such as Minority Serving Institutions and Community Colleges an opportunity for hands on real world research experience. The NSSSC provides students from across the country the opportunity to work as part of an undergraduate interdisciplinary team to design, build and test a ground based solar spectrograph. Over the course of nine months, teams come up with their own science goals and then build an instrument to collect data in support of their goals. Teams then travel to Bozeman, MT to demonstrate their instruments and present their results in a competitive science fair environment. This paper and poster will discuss the 2011-2012 competition along with results as well as provide information on the 2012 -2013 competition opportunities.

  3. Progress on LAMOST High Resolution Spectrograph Project

    NASA Astrophysics Data System (ADS)

    Zhang, KaI

    2015-08-01

    To explore more science case, LAMOST doesn't only has strong power on celestial spectral survey but also reserves an access to high resolution spectrograph with a few optional fibers. This commissioned spectrograph gets high resolution of R=30,000 - 60,000 at a broad visible band from 370nm to 760nm. With the consideration about site seeing variation in future, single science fiber covers wider field on sky of 4.5arcsec instead of the present 3.3arcsec. An oversize Echelle R4 grating and a pre-slit image slicer are adopted to relieve the spectrograph resolution pressure. High resolution observation will parallel to the low resolution spectral survey at a small cost of losing a few fibers (10 - 20) on telescope focal plane. These science fibers will locate at the different sky areas for more approciate choice. The presentation will give the detailed design introduction and the current project status.

  4. Integrating the HERMES spectrograph for the AAT

    NASA Astrophysics Data System (ADS)

    Heijmans, Jeroen; Asplund, Martin; Barden, Sam; Birchall, Michael; Carollo, Daniela; Bland-Hawthorn, Joss; Brzeski, Jurek; Case, Scott; Churilov, Vladimir; Colless, Matthew; Dean, Robert; De Silva, Gayandhi; Farrell, Tony; Fiegert, Kristin; Freeman, Kenneth; Gers, Luke; Goodwin, Michael; Gray, Doug; Heald, Ron; Heng, Anthony; Jones, Damien; Kobayashi, Chiaki; Klauser, Urs; Kondrat, Yuriy; Lawrence, Jon; Lee, Steve; Mathews, Darren; Mayfield, Don; Miziarski, Stan; Monnet, Guy J.; Muller, Rolf; Pai, Naveen; Patterson, Robert; Penny, Ed; Orr, David; Sheinis, Andrew; Shortridge, Keith; Smedley, Scott; Smith, Greg; Stafford, Darren; Staszak, Nicholas; Vuong, Minh; Waller, Lewis; Whittard, Denis; Wylie de Boer, Elisabeth; Xavier, Pascal; Zheng, Jessica; Zhelem, Ross; Zucker, Daniel

    2012-09-01

    The High Efficiency and Resolution Multi Element Spectrograph, HERMES is an optical spectrograph designed primarily for the GALAH, Galactic Archeology Survey, the first major attempt to create a detailed understanding of galaxy formation and evolution by studying the history of our own galaxy, the Milky Way1. The goal of the GALAH survey is to reconstruct the mass assembly history of the of the Milky way, through a detailed spatially tagged abundance study of one million stars in the Milky Way. The spectrograph will be based at the Anglo Australian Telescope (AAT) and be fed with the existing 2dF robotic fibre positioning system. The spectrograph uses VPH-gratings to achieve a spectral resolving power of 28,000 in standard mode and also provides a high resolution mode ranging between 40,000 to 50,000 using a slit mask. The GALAH survey requires a SNR greater than 100 aiming for a star brightness of V=14. The total spectral coverage of the four channels is about 100nm between 370 and 1000nm for up to 392 simultaneous targets within the 2 degree field of view. Current efforts are focused on manufacturing and integration. The delivery date of spectrograph at the telescope is scheduled for 2013. A performance prediction is presented and a complete overview of the status of the HERMES spectrograph is given. This paper details the following specific topics: The approach to AIT, the manufacturing and integration of the large mechanical frame, the opto-mechanical slit assembly, collimator optics and cameras, VPH gratings, cryostats, fibre cable assembly, instrument control hardware and software, data reduction.

  5. Mass producing an efficient NIR spectrograph

    NASA Astrophysics Data System (ADS)

    Wilson, John C.; Henderson, Charles P.; Herter, Terry L.; Matthews, Keith; Skrutskie, Michael F.; Adams, Joseph D.; Moon, Dae-Sik; Smith, Roger; Gautier, Nick; Ressler, Michael; Soifer, B. T.; Lin, Sean; Howard, James; LaMarr, John; Stolberg, Todd M.; Zink, Jeff

    2004-09-01

    Four institutions are collaborating to design and build three near identical R ~2700 cross-dispersed near-infrared spectrographs for use on various 5-10 meter telescopes. The instrument design addresses the common observatory need for efficient, reliable near-infrared spectrographs through such features as broad wavelength coverage across 6 simultaneous orders (0.8 - 2.4 microns) in echelle format, real-time slit viewing through separate optics and detector, and minimal moving parts. Lastly, the collaborators are saving money and increasing the likelihood of success through economies of scale and sharing intellectual capital.

  6. The Spartan-281 Far Ultraviolet Imaging Spectrograph

    NASA Technical Reports Server (NTRS)

    Carruthers, George R.; Heckathorn, Harry M.; Dufour, Reginald J.; Opal, Chet B.; Raymond, John C.

    1988-01-01

    The U.S. Naval Research Laboratory's Far Ultraviolet Imaging Spectrograph (FUVIS), currently under development for flight as a Spartan shuttle payload, is designed to perform spectroscopy of diffuse sources in the FUV with very high sensitivity and moderate spatial and spectral resolution. Diffuse nebulae, the general galactic background radiation, and artificially induced radiation associated with the Space Shuttle vehicle are sources of particular interest. The FUVIS instrument will cover the wavelength range of 970-2000 A with selectable resolutions of 5 and 30 A. It is a slit imaging spectrograph having 3 arcmin spatial resolution along its 2.7 deg long slit.

  7. Initial results from VIRUS production spectrographs

    NASA Astrophysics Data System (ADS)

    Tuttle, Sarah E.; Allen, Richard D.; Chonis, Taylor S.; Cornell, Mark E.; DePoy, Darren L.; Hill, Gary J.; Lee, Hanshin; Marshall, Jennifer L.; Prochaska, Travis; Rafal, Marc D.; Savage, Richard D.; Vattiat, Brian L.

    2012-09-01

    The Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) uses a novel technique of replicated spectrographs (VIRUS) to measure dark energy at intermediate redshifts (2 < z < 4). VIRUS contains over 30,000 fibers and over 160 independent and identical channels. Here we report on the construction and characterization of the initial batch of VIRUS spectrograph cameras. Assembly of the first batch of 16 is in progress. A brief overview of the assembly is presented, and where available performance is compared to specification.

  8. Gauribidanur Low-Frequency Solar Spectrograph

    NASA Astrophysics Data System (ADS)

    Kishore, P.; Kathiravan, C.; Ramesh, R.; Rajalingam, M.; Barve, Indrajit V.

    2014-10-01

    A new radio spectrograph, dedicated to observe the Sun, has been recently commissioned by the Indian Institute of Astrophysics (IIA) at the Gauribidanur Radio Observatory, about 100 km North of Bangalore. The instrument, called the Gauribidanur Low-frequency Solar Spectrograph (GLOSS), operates in the frequency range≈40 - 440 MHz. Radio emission in this frequency range originates close to the Sun, typically in the radial distance range r≈1.1 - 2.0 R⊙. This article describes the characteristics of the GLOSS and the first results.

  9. Adult Compacts.

    ERIC Educational Resources Information Center

    Further Education Unit, London (England).

    This bulletin focuses on adult compacts, three-way agreements among employers, potential employees, and trainers to provide the right kind of quality training to meet the employers' requirements. Part 1 is an executive summary of a report of the Adult Compacts Project, which studied three adult compacts in Birmingham and Loughborough, England, and…

  10. VXMS: the VISTA extreme multiplex spectrograph

    NASA Astrophysics Data System (ADS)

    Content, Robert; Shanks, Tom; Sharples, Ray; Bramall, David; Percival, Will

    2012-09-01

    A study for a spectrograph delivering at least 10000 slits for galaxies and 20000 for stars over a 2.5 deg2 field have been completed as an answer to the call for proposal for future VISTA MOS instrumentation. In a single night, 65000 galaxy redshifts can be measured to z~0.7 and beyond for measuring the Baryon Acoustic Oscillation (BAO) scale and many other science goals. The design features ten cloned spectrographs which give a smaller total weight and length than a unique spectrograph to make it placable in the space envelope of the Cassegrain focus. The clones use a transparent design including a grism in which all optics are about the size or smaller than the clone rectangular subfield so that they can be tightly packed with little gaps between subfields. Only low cost glasses are used; the variations in chromatic aberrations between bands are compensated by changing a box containing the grism and two adjacent lenses. Two bands cover the 550nm to 900nm wavelength range at resolution of 1100 for blue end and 3000 for red end while another cover the Calcium triplet at 5000. An optional box does imaging but we studied different innovative methods for acquisition without imaging. A new 2.3° corrector was designed that places the pupil before and relatively near the focal plane which permits to give more space at the back of the spectrographs by placing them in a hedgehog configuration. An offaxis field lens in each spectrograph permits to control the pupil position.

  11. Astronomical capabilities of the Faint Object Spectrograph on Space Telescope

    NASA Technical Reports Server (NTRS)

    Harms, R. J.

    1982-01-01

    Examples of scientific observing programs planned with the Faint Object Spectrograph on Space Telescope are presented. An overview of the spectrograph design and operation is presented. The expected astronomical performance of the instrument is described in some detail.

  12. Spectrograph Instrumental Profiles - Dependence on Dispersion

    NASA Astrophysics Data System (ADS)

    Andersen, J.; Dravins, D.

    1982-04-01

    Spectrograph instrumental profiles (including stray light far away from the central peak) have been measured in blue and red light for the three cameras in the coudé spectrograph of the 1.52-m telescope at Observatoire de Haute-Provence. The different dispersions 0.7, 1.2, and 2.0 nm mm-1 are obtained using the same ruled diffraction grating. On a linear distance scale in the focal plane the profiles are rather similar down to a 10-3 intensity level, but on a wavelength scale the profiles improve with increasing dispersion, indicating the presence of a stray light component other than that caused by diffraction by grating irregularities. The effects of these instrumental profiles on observed spectra are illustrated by numerical convolutions with the solar spectrum.

  13. WAVELENGTH CALIBRATION OF THE HAMILTON ECHELLE SPECTROGRAPH

    SciTech Connect

    Pakhomov, Yu. V.; Zhao, G.

    2013-10-01

    We present the wavelength calibration of the Hamilton Echelle Spectrograph at Lick Observatory. The main problem with the calibration of this spectrograph arises from the fact that thorium lines are absent in the spectrum of the presumed ThAr hollow-cathode lamp now under operation; numerous unknown strong lines, which have been identified as titanium lines, are present in the spectrum. We estimate the temperature of the lamp's gas which permits us to calculate the intensities of the lines and to select a large number of relevant Ti I and Ti II lines. The resulting titanium line list for the Lick hollow-cathode lamp is presented. The wavelength calibration using this line list was made with an accuracy of about 0.006 Å.

  14. First Results From MAVEN's Imaging UV Spectrograph

    NASA Astrophysics Data System (ADS)

    Schneider, N.; McClintok, W. E.; Stewart, A. I. F.; Deighan, J.; Clarke, J. T.; Holsclaw, G. M.; Montmessin, F.; Lefevre, F.; Chaufray, J. Y.; Jain, S. K.; Stiepen, A.; Chaffin, M. S.; Crismani, M.; Matta, M.; Evans, J. S.; Stevens, M. H.; Yelle, R. V.; Jakosky, B. M.

    2015-10-01

    We report the first results from The Imaging Ultraviolet Spectrograph (IUVS) aboard the Mars Atmosphere and Volatile and EvolutioN (MAVEN)spacecraft orbiting Mars. The instrument is accomplishing its goals of characterizing the atmospheric composition and structure, enabling studies of atmospheric escape that will contribute to our understanding of Mars'atmospheric evolution. In addition, the instrument has made unexpected discoveries concerning meteor showers, aurora and nightglow on Mars.

  15. User Support for the HST Spectrographs

    NASA Astrophysics Data System (ADS)

    Gonnella, A. M.; Christensen, J. A.; Hulbert, S. J.

    1997-12-01

    Plans for user support of the HST spectrographs include the two archival instruments, GHRS and FOS, as well as the currently operational STIS. Support for users of STIS covers the range of proposal preparation, calibration and visits to the institute, whereas support for the archival instruments is not as broad. We describe the ways in which an observer can find support through our extensive World Wide Web resources and the Space Telescope help desk.

  16. A Measurement System for Spectrographic Plates

    NASA Astrophysics Data System (ADS)

    Nylén, Per

    1982-02-01

    An analysis system for measurement and data processing of spectra, recorded on spectrographic plates, is described. The system uses diode arrays for line profile scanning and a television camera for survey. The positions are measured using a Heidenhain equipment, and a micro-computer guides and controls the system. The computer is programmed to support the operator with utility routines for data collection and processing and for operator guidance.

  17. Spectrograph Measures Contamination Of Optical Elements

    NASA Technical Reports Server (NTRS)

    Flint, Bruce K.; Fancy, Robert D.; Jarratt, Robert V., Jr.

    1989-01-01

    Scanning-monochromator spectrograph designed to measure contamination on surfaces of optical elements as function of time. Repeatedly exposes samples to environment, then measures their transmittances or reflectances over range of wavelengths. Intended for use at vacuum-ultraviolet wavelengths to evaluate effects of outgassing, heating, and cooling on optical instruments. Principle of operation also applicable to spectral monitoring of time-dependent contamination at other wavelengths and in laboratory, industrial, or other settings.

  18. Conversational high resolution mass spectrographic data reduction

    NASA Technical Reports Server (NTRS)

    Romiez, M. P.

    1973-01-01

    A FORTRAN 4 program is described which reduces the data obtained from a high resolution mass spectrograph. The program (1) calculates an accurate mass for each line on the photoplate, and (2) assigns elemental compositions to each accurate mass. The program is intended for use in a time-shared computing environment and makes use of the conversational aspects of time-sharing operating systems.

  19. ESOPO a Medium Resolution Optical Spectrograph

    NASA Astrophysics Data System (ADS)

    Farah, A.; Chapa, O.; Cobos, F.; Colorado, E.; Costero, R.; Echevarria, J.; García, B.; Garfias, F.; González, J.; Granados, F.; Guisa, G.; Luna, E.; Martínez, B.; Murillo, F.; Pedrayes, M.; Pérez, F.; Quirós, F.; Tejada, C.; Sierra, G.

    2009-05-01

    The Instituto de Astronomía, of the Universidad Nacional Autónoma de México, after an internal licitation, determined to design and manufacture a Medium Resolution Optical Spectrograph. The instrument will be attached to the 2.1 m telescope at the National Astronomical Observatory at San Pedro Mártir, México. The project was granted to the ESOPO group, winner of the call for proposals. The basic purpose of the project is to equip the observatory with a modern and more efficient spectrograph. Its main goal is to solve astronomical problems that require an ample optical range with a spectral resolution between 500 and 5000. These projects include observations of extended stellar objects, external galaxies, and stars inside our galaxy. In this work we present the scientific goals of ESOPO spectrograph, its translation to high level requirements, its optical design as well as its mechanical design and optomechanics for 24 lenses. The error budget for image quality and motion are included. Finally, management, organization, and first light date of the project are described.

  20. KAOS: kilo-aperture optical spectrograph

    NASA Astrophysics Data System (ADS)

    Barden, Samuel C.; Dey, Arjun; Boyle, Brian; Glazebrook, Karl

    2004-09-01

    A design is described for a potential new facility capable of taking detailed spectroscopy of millions of objects in the Universe to explore the complexity of the Universe and to answer fundamental questions relating to the equation of state of dark energy and to how the Milky Way galaxy formed. The specific design described is envisioned for implementation on the Gemini 8-meter telescopes. It utilizes a 1.5° field of view and samples that field with up to ~5000 apertures. This Kilo-Aperture Optical Spectrograph (KAOS) is mounted at prime focus with a 4-element corrector, atmospheric dispersion compensator (ADC), and an Echidna-style fiber optic positioner. The ADC doubles as a wobble plate, allowing fast guiding that cancels out the wind buffeting of the telescope. The fibers, which can be reconfigured in less than 10 minutes, feed to an array of 12 spectrographs located in the pier of the telescope. The spectrographs are capable of provided spectral resolving powers of a few thousand up to about 40,000.

  1. The Ultraviolet Spectrograph on NASA's Juno Mission

    NASA Astrophysics Data System (ADS)

    Gladstone, G. Randall; Persyn, Steven C.; Eterno, John S.; Walther, Brandon C.; Slater, David C.; Davis, Michael W.; Versteeg, Maarten H.; Persson, Kristian B.; Young, Michael K.; Dirks, Gregory J.; Sawka, Anthony O.; Tumlinson, Jessica; Sykes, Henry; Beshears, John; Rhoad, Cherie L.; Cravens, James P.; Winters, Gregory S.; Klar, Robert A.; Lockhart, Walter; Piepgrass, Benjamin M.; Greathouse, Thomas K.; Trantham, Bradley J.; Wilcox, Philip M.; Jackson, Matthew W.; Siegmund, Oswald H. W.; Vallerga, John V.; Raffanti, Rick; Martin, Adrian; Gérard, J.-C.; Grodent, Denis C.; Bonfond, Bertrand; Marquet, Benoit; Denis, François

    2014-03-01

    The ultraviolet spectrograph instrument on the Juno mission (Juno-UVS) is a long-slit imaging spectrograph designed to observe and characterize Jupiter's far-ultraviolet (FUV) auroral emissions. These observations will be coordinated and correlated with those from Juno's other remote sensing instruments and used to place in situ measurements made by Juno's particles and fields instruments into a global context, relating the local data with events occurring in more distant regions of Jupiter's magnetosphere. Juno-UVS is based on a series of imaging FUV spectrographs currently in flight—the two Alice instruments on the Rosetta and New Horizons missions, and the Lyman Alpha Mapping Project on the Lunar Reconnaissance Orbiter mission. However, Juno-UVS has several important modifications, including (1) a scan mirror (for targeting specific auroral features), (2) extensive shielding (for mitigation of electronics and data quality degradation by energetic particles), and (3) a cross delay line microchannel plate detector (for both faster photon counting and improved spatial resolution). This paper describes the science objectives, design, and initial performance of the Juno-UVS.

  2. An Opto-MEMS Multiobject Spectrograph

    NASA Astrophysics Data System (ADS)

    Kearney, K.; Ninkov, Z.; Zwarg, D.

    2000-05-01

    Optical MEMS (Micro-Electro-Mechanical-Structures) are an enabling technology for a new class of optical instrumentation designs. An opto-MEMS device consists of an array of microfabricated structures, each of which modulates the phase and/or amplitude of an incident light beam. Typically the devices consist of an array of moveable micromirrors - each of which reflects an incident beam in a unique direction (tilt), or with a unique phase shift (piston). One widely available opto-MEMS device is the Texas Instruments' Digital Micromirror Device (DMD). The DMD is an array of 16 micron x 16 micron square mirrors postioned on a 17 micron pitch. Each mirror can tilt +/- 10 degrees from the normal - reflecting a normally incident light beam +/- 20 degrees. By positioning the DMD in an intermediate image plane in an optical system, portions of the image can be directed into- or out-of the input pupil of the follow-on imaging optics. RIT is utilizing the DMD to construct a prototype multiobject spectrograph (RIT-MOS) for visible observations with terrestrial telescopes. The DMD array replaces the input slit of an imaging spectrograph, forming a 'virtual', programmable slit assembly. By acquiring a pre-image of the astronomical field, it is possible to select a multidude of objects, and to program the DMD to pass only those objects into the input optics of the imaging spectrograph. We will report on the design and characterizatotion of the RIT-MOS, as well as preliminary imaging results.

  3. GYES, A Multifibre Spectrograph for the CFHT

    NASA Astrophysics Data System (ADS)

    Bonifacio, P.; Mignot, S.; Dournaux, J.-L.; François, P.; Caffau, E.; Royer, F.; Babusiaux, C.; Arenou, F.; Balkowski, C.; Bienaymé, O.; Briot, D.; Carlberg, R.; Cohen, M.; Dalton, G. B.; Famaey, B.; Fasola, G.; Frémat, Y.; Gómez, A.; Guinouard, I.; Haywood, M.; Hill, V.; Huet, J.-M.; Katz, D.; Horville, D.; Kudritzky, R.; Lallement, R.; Laporte, Ph.; de Laverny, P.; Lemasle, B.; Lewis, I. J.; Martayan, C.; Monier, R.; Mourard, D.; Nardetto, N.; Recio Blanco, A.; Robichon, N.; Robin, A. C.; Rodrigues, M.; Soubiran, C.; Turon, C.; Venn, K.; Viala, Y.

    2011-02-01

    We have chosen the name of GYES, one of the mythological giants with one hundred arms, offspring of Gaia and Uranus, for our instrument study of a multifibre spectrograph for the prime focus of the Canada-France-Hawaii Telescope. Such an instrument could provide an excellent ground-based complement for the Gaia mission and a northern complement to the HERMES project on the AAT. The CFHT is well known for providing a stable prime focus environment, with a large field of view, which has hosted several imaging instruments, but has never hosted a multifibre spectrograph. Building upon the experience gained at GÉPI with FLAMES-Giraffe and X-Shooter, we are investigating the feasibility of a high multiplex spectrograph (about 500 fibres) over a field of view one degree in diameter. We are investigating an instrument with resolution in the range 15 000 to 30 000, which should provide accurate chemical abundances for stars down to 16th magnitude and radial velocities, accurate to 1 km s-1 for fainter stars. The study is led by GÉPI-Observatoire de Paris with a contribution from Oxford for the study of the positioner. The financing for the study comes from INSU CSAA and Observatoire de Paris. The conceptual study will be delivered to CFHT for review by October 1st 2010.

  4. Optical design of a versatile FIRST high-resolution near-IR spectrograph

    NASA Astrophysics Data System (ADS)

    Zhao, Bo; Ge, Jian

    2012-09-01

    We report the update optical design of a versatile FIRST high resolution near IR spectrograph, which is called Florida IR Silicon immersion grating spectromeTer (FIRST). This spectrograph uses cross-dispersed echelle design with white pupils and also takes advantage of the image slicing to increase the spectra resolution, while maintaining the instrument throughput. It is an extremely high dispersion R1.4 (blazed angle of 54.74°) silicon immersion grating with a 49 mm diameter pupil is used as the main disperser at 1.4μm -1.8μm to produce R=72,000 while an R4 echelle with the same pupil diameter produces R=60,000 at 0.8μm -1.35μm. Two cryogenic Volume Phase Holographic (VPH) gratings are used as cross-dispersers to allow simultaneous wavelength coverage of 0.8μm -1.8μm. The butterfly mirrors and dichroic beamsplitters make a compact folding system to record these two wavelength bands with a 2kx2k H2RG array in a single exposure. By inserting a mirror before the grating disperser (the SIG and the echelle), this spectrograph becomes a very efficient integral field 3-D imaging spectrograph with R=2,000-4,000 at 0.8μm-1.8μm by coupling a 10x10 telescope fiber bundle with the spectrograph. Details about the optical design and performance are reported.

  5. VIBRATION COMPACTION

    DOEpatents

    Hauth, J.J.

    1962-07-01

    A method of compacting a powder in a metal container is described including the steps of vibrating the container at above and below the resonant frequency and also sweeping the frequency of vibration across the resonant frequency several times thereby following the change in resonant frequency caused by compaction of the powder. (AEC)

  6. PRAXIS: low thermal emission high efficiency OH suppressed fibre spectrograph

    NASA Astrophysics Data System (ADS)

    Content, Robert; Bland-Hawthorn, Joss; Ellis, Simon; Gers, Luke; Haynes, Roger; Horton, Anthony; Lawrence, Jon; Leon-Saval, Sergio; Lindley, Emma; Min, Seong-Sik; Shortridge, Keith; Staszak, Nick; Trinh, Christopher; Xavier, Pascal; Zhelem, Ross

    2014-07-01

    PRAXIS is a second generation instrument that follows on from GNOSIS, which was the first instrument using fibre Bragg gratings for OH suppression to be deployed on a telescope. The Bragg gratings reflect the NIR OH lines while being transparent to the light between the lines. This gives in principle a much higher signal-noise ratio at low resolution spectroscopy but also at higher resolutions by removing the scattered wings of the OH lines. The specifications call for high throughput and very low thermal and detector noise so that PRAXIS will remain sky noise limited even with the low sky background levels remaining after OH suppression. The optical and mechanical designs are presented. The optical train starts with fore-optics that image the telescope focal plane on an IFU which has 19 hexagonal microlenses each feeding a multi-mode fibre. Seven of these fibres are attached to a fibre Bragg grating OH suppression system while the others are reference/acquisition fibres. The light from each of the seven OH suppression fibres is then split by a photonic lantern into many single mode fibres where the Bragg gratings are imprinted. Another lantern recombines the light from the single mode fibres into a multi-mode fibre. A trade-off was made in the design of the IFU between field of view and transmission to maximize the signal-noise ratio for observations of faint, compact objects under typical seeing. GNOSIS used the pre-existing IRIS2 spectrograph while PRAXIS will use a new spectrograph specifically designed for the fibre Bragg grating OH suppression and optimised for 1.47 μm to 1.7 μm (it can also be used in the 1.09 μm to 1.26 μm band by changing the grating and refocussing). This results in a significantly higher transmission due to high efficiency coatings, a VPH grating at low incident angle and optimized for our small bandwidth, and low absorption glasses. The detector noise will also be lower thanks to the use of a current generation HAWAII-2RG detector

  7. Exact optics - III. Schwarzschild's spectrograph camera revised

    NASA Astrophysics Data System (ADS)

    Willstrop, R. V.

    2004-03-01

    Karl Schwarzschild identified a system of two mirrors, each defined by conic sections, free of third-order spherical aberration, coma and astigmatism, and with a flat focal surface. He considered it impractical, because the field was too restricted. This system was rediscovered as a quadratic approximation to one of Lynden-Bell's `exact optics' designs which have wider fields. Thus the `exact optics' version has a moderate but useful field, with excellent definition, suitable for a spectrograph camera. The mirrors are strongly aspheric in both the Schwarzschild design and the exact optics version.

  8. Upgrade of the area II spectrograph

    SciTech Connect

    Rehm, K.E.; Bolduc, C.

    1995-08-01

    Because of the low beam energies required for experiments of astrophysical interest, the first test experiments with radioactive {sup 18}F beams can be performed in Area II. Because of the shorter distances between ion source and detector this also results in higher transmission efficiencies. The Enge split-pole spectrograph, which was not used during the last 8 years, was equipped with a new cryopump system, upgrades to the magnet power supply and the NMR system were performed. A rotating target system was built which should alleviate target deterioration effects that were observed in first test experiments.

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

    SciTech Connect

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

    2004-10-01

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

  10. The GlobalJetWatch spectrographs: a fibre-fed spectrograph for small telescopes

    NASA Astrophysics Data System (ADS)

    Clarke, Fraser J.; Gosling, Andrew J.; Doolin, Sam; Goodall, Paul; Perez, Sebastian; Pattinson, Paul; Makin, Rick; Blundell, Katherine M.

    2008-07-01

    The GlobalJetWatch project (www.globaljetwatch.net) will place small (0.5-metre) commerical telescopes in four schools around the world. Each telescope will be equipped with a custom designed spectrograph, currently being built by the Astrophysics sub-department of the University of Oxford. The scientific goal of the project is to provide continual monitoring of a rosetta stone object, the micro-quasar SS433. In addition, the project has a significant out-reach element, aiming to involve school children on four-continents in front-line astronomical research. The spectrograph is a fibre-fed fixed format cross-dispersed echellete design providing R~6000 spectra from 4300-8500 in a single exposure. The spectrograph is built almost entirely from off-the-shelf components. The four GlobalJetWatch sites (Australia, India, South Africa, Chile) will be commissioned in 2008/09. Here we present the baseline design of the spectrograph, and initial results from the prototype on-sky commissioning in Oxford.

  11. The Faulkes Telescope Optical Spectrographs and Swift

    NASA Astrophysics Data System (ADS)

    O'Brien, Paul

    The Faulkes Telescope project funded primarily by the Dill Faulkes Educational Trust is currently constructing two 2-m robotic telescopes to be located in Hawaii and Australia. These will be the largest and most powerful telescopes ever built dedicated for use by schools and colleges. We have been awarded funding to build two optical spectrographs to be permanently mounted on these telescopes by the end of 2003. At this time an astronomical satellite called Swift will be launched by NASA. Swift is dedicated to the study of gamma-ray bursts the most powerful explosive events in the Universe. The Department of Physics and Astronomy at the University of Leicester has provided the X-ray camera for Swift and is a partner in the Faulkes Telescopes project. To enhance both projects we intend to use the Faulkes Telescope optical spectrographs to study the gamma-ray bursts identified by Swift. These data will also be made available to schools thereby raising the profile of physics and astronomy in the educational community.

  12. Field Raman Spectrograph for Environmental Analysis

    SciTech Connect

    Sylvia, J.M.; Haas, J.W.; Spencer, K.M.; Carrabba, M.M.; Rauh, R.D.; Forney, R.W.; Johnston, T.M.

    1998-07-01

    The widespread contamination found across the US Department of Energy (DOE) complex has received considerable attention from the government and public alike. A massive site characterization and cleanup effort has been underway for several years and is expected to continue for several decades more. The scope of the cleanup effort ranges from soil excavation and treatment to complete dismantling and decontamination of whole buildings. To its credit, DOE has supported research and development of new technologies to speed up and reduce the cost of this effort. One area in particular has been the development of portable instrumentation that can be used to perform analytical measurements in the field. This approach provides timely data to decision makers and eliminates the expense, delays, and uncertainties of sample preservation, transport, storage, and laboratory analysis. In this program, we have developed and demonstrated in the field a transportable, high performance Raman spectrograph that can be used to detect and identify contaminants in a variety of scenarios. With no moving parts, the spectrograph is rugged and can perform many Raman measurements in situ with flexible fiber optic sampling probes. The instrument operates under computer control and a software package has been developed to collect and process spectral data. A collection of Raman spectra for 200 contaminants of DOE importance has been compiled in a searchable format to assist in the identification of unknown contaminants in the field.

  13. LOTUS: a low-cost, ultraviolet spectrograph

    NASA Astrophysics Data System (ADS)

    Steele, I. A.; Marchant, J. M.; Jermak, H. E.; Barnsley, R. M.; Bates, S. D.; Clay, N. R.; Fitzsimmons, A.; Jehin, E.; Jones, G.; Mottram, C. J.; Smith, R. J.; Snodgrass, C.; de Val-Borro, M.

    2016-08-01

    We describe the design, construction and commissioning of LOTUS; a simple, low-cost long-slit spectrograph for the Liverpool Telescope. The design is optimized for near-UV and visible wavelengths and uses all transmitting optics. It exploits the instrument focal plane field curvature to partially correct axial chromatic aberration. A stepped slit provides narrow (2.5x95 arcsec) and wide (5x25 arcsec) options that are optimized for spectral resolution and flux calibration respectively. On sky testing shows a wavelength range of 3200-6300 Angstroms with a peak system throughput (including detector quantum efficiency) of 15 per cent and wavelength dependant spectral resolution of R=225-430. By repeated observations of the symbiotic emission line star AG Peg we demonstrate the wavelength stability of the system is less than 2 Angstroms rms and is limited by the positioning of the object in the slit. The spectrograph is now in routine operation monitoring the activity of comet 67P/Churyumov-Gerasimenko during its current post-perihelion apparition.

  14. LOTUS: A low cost, ultraviolet spectrograph

    NASA Astrophysics Data System (ADS)

    Steele, I. A.; Marchant, J. M.; Jermak, H. E.; Barnsley, R. M.; Bates, S. D.; Clay, N. R.; Fitzsimmons, A.; Jehin, E.; Jones, G.; Mottram, C. J.; Smith, R. J.; Snodgrass, C.; de Val-Borro, M.

    2016-05-01

    We describe the design, construction and commissioning of LOTUS; a simple, low-cost long-slit spectrograph for the Liverpool Telescope. The design is optimized for near-UV and visible wavelengths and uses all transmitting optics. It exploits the instrument focal plane field curvature to partially correct axial chromatic aberration. A stepped slit provides narrow (2.5 × 95 arcsec) and wide (5 × 25 arcsec) options that are optimized for spectral resolution and flux calibration respectively. On sky testing shows a wavelength range of 3200-6300 Å with a peak system throughput (including detector quantum efficiency) of 15 per cent and wavelength dependant spectral resolution of R = 225 - 430. By repeated observations of the symbiotic emission line star AG Peg we demonstrate the wavelength stability of the system is <2 Å rms and is limited by the positioning of the object in the slit. The spectrograph is now in routine operation monitoring the activity of comet 67P/Churyumov-Gerasimenko during its current post-perihelion apparition.

  15. LOTUS: a low-cost, ultraviolet spectrograph

    NASA Astrophysics Data System (ADS)

    Steele, I. A.; Marchant, J. M.; Jermak, H. E.; Barnsley, R. M.; Bates, S. D.; Clay, N. R.; Fitzsimmons, A.; Jehin, E.; Jones, G.; Mottram, C. J.; Smith, R. J.; Snodgrass, C.; de Val-Borro, M.

    2016-08-01

    We describe the design, construction and commissioning of a simple, low-cost long-slit spectrograph for the Liverpool Telescope. The design is optimized for near-UV and visible wavelengths and uses all transmitting optics. It exploits the instrument focal plane field curvature to partially correct axial chromatic aberration. A stepped slit provides narrow (2.5 × 95 arcsec) and wide (5 × 25 arcsec) options that are optimized for spectral resolution and flux calibration, respectively. On sky testing shows a wavelength range of 3200-6300 Å with a peak system throughput (including detector quantum efficiency) of 15 per cent and wavelength dependent spectral resolution of R = 225-430. By repeated observations of the symbiotic emission line star AG Peg, we demonstrate the wavelength stability of the system is <2 Å rms and is limited by the positioning of the object in the slit. The spectrograph is now in routine operation monitoring the activity of comet 67P/Churyumov-Gerasimenko during its current post-perihelion apparition.

  16. Advanced prism-grating-prism imaging spectrograph in online industrial applications

    NASA Astrophysics Data System (ADS)

    Vaarala, Tapio; Aikio, Mauri; Keraenen, Heimo

    1997-08-01

    Imaging spectrographs have traditionally been utilized in aerial and remote sensing applications. A novel, compact and inexpensive imaging spectrograph developed by VTT Electronics is now available. It contains a multichannel fiber optic sensor head, a dispersive prism-grating-prism (PGP) component and digital CCD matrix camera capable of area integration. In rolled steel manufacturing, a protective oil film is applied on steel to resist corrosion while in transport and storage. The main problems in the oiling machine are film thickness control and jet failures. In this application, the spectrum of fluorescence of an oil film was measured simultaneously with parallel fibers. A relatively simple calibration and analysis procedure was used to calculate the oil film thickness. On-line color control for color reproduction is essential in both consumer and industrial products. The instrument was tested and analyzed for measuring differences in color by multivariate analysis of the spectra and by color space coordinate estimation. In general, a continuous spectrum is not absolute requirement. In these two examples, filter-based measurement would probably cost less thana PGP spectrograph solution. On the other hand, by measuring the spectrum and using an advanced signal processing algorithm one production version will cover all installations in both applications. In practice, only the fiber sensor mechanics need to be modified.

  17. Laue transmission x-ray spectrograph for inertial confinement fusion (ICF) diagnostics

    NASA Astrophysics Data System (ADS)

    Burek, A. J.

    1992-01-01

    An absolutely calibrated, focusing Laue transmission crystal spectrograph has been developed for inertial confinement fusion (ICF) diagnostics of high-energy x-ray continuum at NOVA. A single flat EddT 020 crystal, 500-μm thick, provides continuous energy coverage over the 5.5-25 keV energy range. The spectrograph is designed with low dispersion and low resolving power E/ΔE of between 10 and 50 for high sensitivity to continuum. Greater resolving power with lower continuum sensitivity is possible by increasing dispersion. The focusing design achieves very low background and provides a compact flat field for coupling to various position sensitive detectors including streak cameras. In addition to EddT, PET 020 has high efficiency in transmission in this energy range and used in the Cauchois geometry achieves high to moderate resolving power that is independent of ICF source size. Initial experiments with gold targets at NOVA with the EddT spectrograph show high sensitivity for single shot recording of continuum and gold L lines on Kodak DEF film. Factors affecting instrument design, resolving power, and sensitivity will be discussed.

  18. LRS2: A New Integral Field Spectrograph for the HET

    NASA Astrophysics Data System (ADS)

    Tuttle, Sarah E.; Hill, Gary J.; Chonis, Taylor S.; Tonnesen, Stephanie

    2016-01-01

    Here we present LRS2 (Low Resolution Spectrograph) and highlight early science opportunities with the newly upgraded Hobby Eberly telescope (HET). LRS2 is a four-channel optical wavelength (370nm - 1micron) spectrograph based on two VIRUS unit spectrographs. This fiber-fed integral field spectrograph covers a 12" x 6" field of view, switched between the two units (one blue, and one red) at R~2000. We highlight design elements, including the fundamental modification to grisms (from VPH gratings in VIRUS) to access the higher resolution. We discuss early science opportunities, including investigating nearby "blue-bulge" spiral galaxies and their anomalous star formation distribution.

  19. The deterministic optical alignment of the HERMES spectrograph

    NASA Astrophysics Data System (ADS)

    Gers, Luke; Staszak, Nicholas

    2014-07-01

    The High Efficiency and Resolution Multi Element Spectrograph (HERMES) is a four channel, VPH-grating spectrograph fed by two 400 fiber slit assemblies whose construction and commissioning has now been completed at the Anglo Australian Telescope (AAT). The size, weight, complexity, and scheduling constraints of the system necessitated that a fully integrated, deterministic, opto-mechanical alignment system be designed into the spectrograph before it was manufactured. This paper presents the principles about which the system was assembled and aligned, including the equipment and the metrology methods employed to complete the spectrograph integration.

  20. Ureilite compaction

    NASA Astrophysics Data System (ADS)

    Walker, D.; Agee, C. B.

    1988-03-01

    Ureilite meteorites show the simple mineralogy and compact recrystallized textures of adcumulate rock or melting residues. A certain amount of controversy exists about whether they are in fact adcumulate rocks or melting residues and about the nature of the precursor liquid or solid assemblage. The authors undertook a limited experimental study which made possible the evaluation of the potential of the thermal migration mechanism (diffusion on a saturation gradient) for forming ureilite-like aggregates from carbonaceous chondrite precursors. They find that the process can produce compact recrystallized aggregates of silicate crystals which do resemble the ureilities and other interstitial-liquid-free adcumulate rocks in texture.

  1. KISS - The Kiepenheuer Institute Solar Spectrograph

    NASA Astrophysics Data System (ADS)

    Gerndt, Ruediger; Hoelzle, Edgar

    The experimental requirements and corresponding design features of the Kiepenheuer Institute Solar Spectrograph (KISS) are set forth with references to its role in NASA's Orbiting Solar Laboratory (OSL). The optical subsystem incorporates four CCD cameras and a rotating-mirror sun-scanner unit, and the mechanical structure is composed of hollow CFRP beams. The instrument is designed to collect spatially resolved dynamical data regarding the solar atmosphere's velocity field based on the Doppler-induced spectral-line structures. The optical parameters of the instrument are listed, and the configuration of the OSL requires that the KISS is an autonomous subunit within the coordinated instrument package. KISS is expected to provide the capacity for spectroscopic studies of dynamical elements of the solar atmosphere at time scales of at least 10 s.

  2. CFHT MOS/SIS spectrograph performance

    NASA Astrophysics Data System (ADS)

    Le Fevre, O.; Crampton, D.; Felenbok, P.; Monnet, G.

    1994-02-01

    Initial results of laboratory and on-sky tests of the new Canada-France-Hawaii Telescope (CFHT) multi-object spectrograph, metal oxide semiconductor (MOS)/superconducting / insulating / superconducting (SIS), are described. MOS/SIS contains two ways, one of which is primarily intended for imagery and spectroscopy of many tens of objects within a 10 min field, while the other utilizes tip/tilt image stabilization for high spatial resolution imagery and spectroscopy over a 3 min field. Data on image quality, transmission, flexure and stability are presented, as well as a description of the multi-object observing performance. This highly integrated system incorporates yttrium-aluminum garnet (YAG) laser drilling equipment and allows on-line acquisition, aperture mask design and fabrication for multi-slit observations with minimum overhead. A comprehensive software interface provides observers with a user-friendly environment and ensures that all operations can be quickly and efficiently controlled by novice users.

  3. Aries x ray objective grating spectrograph

    NASA Technical Reports Server (NTRS)

    Catura, R. C.

    1991-01-01

    This investigation was initiated in June of 1983. An Aries payload involving a single Wolter 1 telescope was developed and flown under a previous contract and the objective of this work was to add two additional mirrors, nested inside of the then existing mirror and add 12 objective reflection gratings to convert the telescope into a spectrograph. A summary of major milestones in the investigation are given. Results of efforts under this contract prior to 1987 are presented in the form of four reprints of published papers attached to this report. Results of the gamma-ray research are also included in the form of an attached reprint. A summary of other work under the contract since 1987 is given.

  4. A Far Ultraviolet Imaging Spectrograph for Shuttle

    NASA Technical Reports Server (NTRS)

    Carruthers, G. R.

    1984-01-01

    The development of the Far Ultraviolet Imaging Spectrograph (FUVIS) Shuttle sortie missions, is described. Objectives of the experiment are to obtain spatially-resolved far-ultraviolet spectra of extraterrestrial sources, including emission-line and reflection nebulae, diffuse background radiation, extragalactic objects, and comets. The use of fast focal ratio (f/1) Schmidt optics and an opaque CsI photocathode which affords high quantum efficiency in the far-UV provides the maximum possible diffuse source sensitivity. Measured emission line intensities of 5 Rayleighs (or continua of intensity 1 R/A) in 300 sec exposures are expected. The development includes a dedicated pointing platform and a low light level television camera for payload specialist use in target acquisition and guiding.

  5. Fiber Scrambling for High Precision Spectrographs

    NASA Astrophysics Data System (ADS)

    Kaplan, Zachary; Spronck, J. F. P.; Fischer, D.

    2011-05-01

    The detection of Earth-like exoplanets with the radial velocity method requires extreme Doppler precision and long-term stability in order to measure tiny reflex velocities in the host star. Recent planet searches have led to the detection of so called "super-Earths” (up to a few Earth masses) that induce radial velocity changes of about 1 m/s. However, the detection of true Earth analogs requires a precision of 10 cm/s. One of the largest factors limiting Doppler precision is variation in the Point Spread Function (PSF) from observation to observation due to changes in the illumination of the slit and spectrograph optics. Thus, this stability has become a focus of current instrumentation work. Fiber optics have been used since the 1980's to couple telescopes to high-precision spectrographs, initially for simpler mechanical design and control. However, fiber optics are also naturally efficient scramblers. Scrambling refers to a fiber's ability to produce an output beam independent of input. Our research is focused on characterizing the scrambling properties of several types of fibers, including circular, square and octagonal fibers. By measuring the intensity distribution after the fiber as a function of input beam position, we can simulate guiding errors that occur at an observatory. Through this, we can determine which fibers produce the most uniform outputs for the severest guiding errors, improving the PSF and allowing sub-m/s precision. However, extensive testing of fibers of supposedly identical core diameter, length and shape from the same manufacturer has revealed the "personality” of individual fibers. Personality describes differing intensity patterns for supposedly duplicate fibers illuminated identically. Here, we present our results on scrambling characterization as a function of fiber type, while studying individual fiber personality.

  6. Production-line assembly of 150+ VIRUS spectrographs

    NASA Astrophysics Data System (ADS)

    Marshall, J. L.; Vattiat, Brian; DePoy, D. L.; Hill, Gary J.; Collins, Amanda D.; Lee, Hanshin; Allen, Richard D.; Kelz, Andreas; Bauer, Svend M.; Popow, Emil

    2010-07-01

    The Visual Integral-Field Replicable Unit Spectrograph (VIRUS) instrument is being built to support observations for the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) project. The instrument consists of 150+ identical fiber-fed integral field optical spectrographs. This instrument provides a unique challenge in astronomical instrumentation: each of the 150+ instruments must be identical and each component must be interchangeable amongst every other spectrograph in order to ease assembly and maintenance of the instrument. In this paper we describe plans for the production-line assembly of the spectrographs. In particular, we discuss the assembly procedures and design choices that will ensure uniformity of the spectrographs and support the project schedule.

  7. A multipurpose fiber-fed VPHG spectrograph for LAMOST

    NASA Astrophysics Data System (ADS)

    Zhu, Yongtian; Hu, Zhongwen; Zhang, Qingfeng; Wang, Lei; Wang, Jianing

    2006-06-01

    A multipurpose fiber-fed double-beam Schmidt spectrograph using VPHG (volume phase holographic gratings) is under construction for LAMOST (The Large Sky Area Multi-Object Fiber Spectroscopic Telescope). There are 16 such spectrographs (hereafter referred to as LRSs) for the project. The spectrographs are designed with wavelength coverage from 370 to 900 nm, with spectral resolutions of 1000-10000, and with multi-object capability over a 5 degrees field of view. Each spectrograph will be accommodating 250 fibers of 320 microns diameter (corresponding 3.3 arcsecs). The 200 mm diameter collimated beam is split into two separate channels. The blue channel is optimized for 370nm-590nm, and the red channel for 570nm-900nm. The LRS can work in several varied resolution modes. The optical design and performance is described. The spectrograph is of simple design with moderate image quality and good throughput. Progress on the construction of LRS is reported as well.

  8. Modelling high resolution Echelle spectrographs for calibrations: Hanle Echelle spectrograph, a case study

    NASA Astrophysics Data System (ADS)

    Chanumolu, Anantha; Jones, Damien; Thirupathi, Sivarani

    2015-06-01

    We present a modelling scheme that predicts the centroids of spectral line features for a high resolution Echelle spectrograph to a high accuracy. Towards this, a computing scheme is used, whereby any astronomical spectrograph can be modelled and controlled without recourse to a ray tracing program. The computations are based on paraxial ray trace and exact corrections added for certain surface types and Buchdahl aberration coefficients for complex modules. The resultant chain of paraxial ray traces and corrections for all relevant components is used to calculate the location of any spectral line on the detector under all normal operating conditions with a high degree of certainty. This will allow a semi-autonomous control using simple in-house, programming modules. The scheme is simple enough to be implemented even in a spreadsheet or in any scripting language. Such a model along with an optimization routine can represent the real time behaviour of the instrument. We present here a case study for Hanle Echelle Spectrograph. We show that our results match well with a popular commercial ray tracing software. The model is further optimized using Thorium Argon calibration lamp exposures taken during the preliminary alignment of the instrument. The model predictions matched the calibration frames at a level of 0.08 pixel. Monte Carlo simulations were performed to show the photon noise effect on the model predictions.

  9. Compact accelerator

    DOEpatents

    Caporaso, George J.; Sampayan, Stephen E.; Kirbie, Hugh C.

    2007-02-06

    A compact linear accelerator having at least one strip-shaped Blumlein module which guides a propagating wavefront between first and second ends and controls the output pulse at the second end. Each Blumlein module has first, second, and third planar conductor strips, with a first dielectric strip between the first and second conductor strips, and a second dielectric strip between the second and third conductor strips. Additionally, the compact linear accelerator includes a high voltage power supply connected to charge the second conductor strip to a high potential, and a switch for switching the high potential in the second conductor strip to at least one of the first and third conductor strips so as to initiate a propagating reverse polarity wavefront(s) in the corresponding dielectric strip(s).

  10. The Interface Region Imaging Spectrograph (IRIS)

    NASA Astrophysics Data System (ADS)

    De Pontieu, B.; Title, A. M.; Lemen, J. R.; Kushner, G. D.; Akin, D. J.; Allard, B.; Berger, T.; Boerner, P.; Cheung, M.; Chou, C.; Drake, J. F.; Duncan, D. W.; Freeland, S.; Heyman, G. F.; Hoffman, C.; Hurlburt, N. E.; Lindgren, R. W.; Mathur, D.; Rehse, R.; Sabolish, D.; Seguin, R.; Schrijver, C. J.; Tarbell, T. D.; Wülser, J.-P.; Wolfson, C. J.; Yanari, C.; Mudge, J.; Nguyen-Phuc, N.; Timmons, R.; van Bezooijen, R.; Weingrod, I.; Brookner, R.; Butcher, G.; Dougherty, B.; Eder, J.; Knagenhjelm, V.; Larsen, S.; Mansir, D.; Phan, L.; Boyle, P.; Cheimets, P. N.; DeLuca, E. E.; Golub, L.; Gates, R.; Hertz, E.; McKillop, S.; Park, S.; Perry, T.; Podgorski, W. A.; Reeves, K.; Saar, S.; Testa, P.; Tian, H.; Weber, M.; Dunn, C.; Eccles, S.; Jaeggli, S. A.; Kankelborg, C. C.; Mashburn, K.; Pust, N.; Springer, L.; Carvalho, R.; Kleint, L.; Marmie, J.; Mazmanian, E.; Pereira, T. M. D.; Sawyer, S.; Strong, J.; Worden, S. P.; Carlsson, M.; Hansteen, V. H.; Leenaarts, J.; Wiesmann, M.; Aloise, J.; Chu, K.-C.; Bush, R. I.; Scherrer, P. H.; Brekke, P.; Martinez-Sykora, J.; Lites, B. W.; McIntosh, S. W.; Uitenbroek, H.; Okamoto, T. J.; Gummin, M. A.; Auker, G.; Jerram, P.; Pool, P.; Waltham, N.

    2014-07-01

    The Interface Region Imaging Spectrograph (IRIS) small explorer spacecraft provides simultaneous spectra and images of the photosphere, chromosphere, transition region, and corona with 0.33 - 0.4 arcsec spatial resolution, two-second temporal resolution, and 1 km s-1 velocity resolution over a field-of-view of up to 175 arcsec × 175 arcsec. IRIS was launched into a Sun-synchronous orbit on 27 June 2013 using a Pegasus-XL rocket and consists of a 19-cm UV telescope that feeds a slit-based dual-bandpass imaging spectrograph. IRIS obtains spectra in passbands from 1332 - 1358 Å, 1389 - 1407 Å, and 2783 - 2834 Å, including bright spectral lines formed in the chromosphere (Mg ii h 2803 Å and Mg ii k 2796 Å) and transition region (C ii 1334/1335 Å and Si iv 1394/1403 Å). Slit-jaw images in four different passbands (C ii 1330, Si iv 1400, Mg ii k 2796, and Mg ii wing 2830 Å) can be taken simultaneously with spectral rasters that sample regions up to 130 arcsec × 175 arcsec at a variety of spatial samplings (from 0.33 arcsec and up). IRIS is sensitive to emission from plasma at temperatures between 5000 K and 10 MK and will advance our understanding of the flow of mass and energy through an interface region, formed by the chromosphere and transition region, between the photosphere and corona. This highly structured and dynamic region not only acts as the conduit of all mass and energy feeding into the corona and solar wind, it also requires an order of magnitude more energy to heat than the corona and solar wind combined. The IRIS investigation includes a strong numerical modeling component based on advanced radiative-MHD codes to facilitate interpretation of observations of this complex region. Approximately eight Gbytes of data (after compression) are acquired by IRIS each day and made available for unrestricted use within a few days of the observation.

  11. High resolution spectrograph for the Space Telescope

    NASA Technical Reports Server (NTRS)

    Brandt, J. C.; Boggess, A.; Heap, S. R.; Maran, S. P.; Smith, A. M.; Beaver, E. A.; Bottema, M.; Hutchings, J. B.; Jura, M. A.; Linsky, J. L.

    1979-01-01

    The high resolution spectrograph (HRS) for ultraviolet astronomy with the Space Telescope will provide a spectral resolution of approximately 120,000 over a nominal wavelength range of 110-320 nm, together with a spatial resolution of about 0.25 arc seconds. The two detectors will consist of 512-element Digicons with cesium telluride and cesium iodide photocathodes, respectively. Photoelectrons in transit between the photocathodes and the diodes within the Digicons can be deflected in two axes with 12-bit resolution. This feature facilitates a design that emphasizes reliability since (once a hermetic seal is opened in orbit), only two moving parts, a grating carrousel and a shutter, are required for regular operation of the HRS. The instrument will be controlled by a computer in the spacecraft. The scientific objectives of the HRS investigation relate to interstellar matter in our own and nearby galaxies, physical processes of stellar mass loss and mass transfer, chemical abundances, bright quasars and Seyfert galaxy nuclei, and solar system phenomena.

  12. SDOSS: A spatially discriminating, optical streaked spectrograph

    SciTech Connect

    Cobble, J.; Evans, S.; Fernandez, J.; Oertel, J.; Watt, R.; Wilde, B.

    1995-05-01

    SDOSS is employed to study broadband laser scattering encompassing SBS, SRS, and the 3/2-{omega} signature of two plasmon decay for ns-scale laser-plasma experiments with 351 or 527-nm drive. It uses a Cassegrain telescope to image scattered light from a laser plasma onto a field stop. The telescope magnification and the stop aperture provide spatial discrimination of target plane scatter. A UV lens relays the image to a 0.25-m spectrograph which is lens coupled to a streak camera with an S-1 photocathode. The streak output is imaged onto a CCD camera. In its 512 x 480 pixel array, the CCD covers a spectral range from 200 to 800 nm with 4-nm resolution and can be adjusted to look from 350 to 1,060 nm. The sweep speed is variable with full window values of 30, 12, 6 ns, and faster. An optical fiducial provides a spectral and temporal marker. On the Livermore Nova laser, SDOSS has been used to determine spatial density in gas-filled hohlraums from SRS signals. At Trident in Los Alamos, it has been employed for similar measurements with long scale length plasmas in SBS and SRS seeding experiments. It has proven to be a versatile tool for studying the physics of laser-generated plasmas.

  13. Fibre positioning algorithms for the WEAVE spectrograph

    NASA Astrophysics Data System (ADS)

    Terrett, David L.; Lewis, Ian J.; Dalton, Gavin; Abrams, Don Carlos; Aguerri, J. Alfonso L.; Bonifacio, Piercarlo; Middleton, Kevin; Trager, Scott C.

    2014-07-01

    WEAVE is the next-generation wide-field optical spectroscopy facility for the William Herschel Telescope (WHT) in La Palma, Canary Islands, Spain. It is a multi-object "pick and place" fibre fed spectrograph with more than one thousand fibres, similar in concept to the Australian Astronomical Observatory's 2dF1 instrument with two observing plates, one of which is observing the sky while other is being reconfigured by a robotic fibre positioner. It will be capable of acquiring more than 10000 star or galaxy spectra a night. The WEAVE positioner concept uses two robots working in tandem in order to reconfigure a fully populated field within the expected 1 hour dwell-time for the instrument (a good match between the required exposure times and the limit of validity for a given configuration due to the effects of differential refraction). This presents additional constraints and complications for the software that determines the optimal path from one configuration to the next, particularly given the large number of fibre crossings implied by the 1000 fibre multiplex. This paper describes the algorithms and programming techniques used in the prototype implementations of the field configuration tool and the fibre positioner robot controller developed to support the detailed design of WEAVE.

  14. Interstellar Medium Absorption Profile Spectrograph (IMAPS)

    NASA Technical Reports Server (NTRS)

    Jenkins, E. B.

    1985-01-01

    The design and fabrication of an objective-grating echelle spectrograph to fly on sounding rockets and record spectra of stars from approximately 920 to 1120A with a resolving power lambda/delta lambda = 200,000 is discussed. The scientific purpose of the program is to observe, with ten times better velocity resolution than before, the plentiful absorption lines in this spectral region produced by atoms, ions and molecules in the interstellar medium. In addition, an important technical goal is to develop and flight-quality a new ultraviolet, photon-counting image sensor which has a windowless, opaque photocathode and a CCD bombarded directly by the accelerated photoelectrons. Except for some initial difficulties with the performance of CCDs, the development of the payload instrument is relatively straightforward and our overall design goals are satisfied. The first flight occurred in late 1984, but no data were obtained because of an inrush of air degraded the instrument's vacuum and caused the detector's high voltage to arc. A second flight in early 1985 was a complete success and obtained a spectrum of pi Sco. Data from this mission are currently being reduced; quick-look versions of the spectra indicate that excellent results will be obtained. Currently, the payload is being reconfigured to fly on a Spartan mission in 1988.

  15. Aberration corrected aspheric grating for far ultraviolet spectrographs - Conventional approach

    NASA Technical Reports Server (NTRS)

    Content, David; Trout, Catherine; Davila, Pam; Wilson, Mark

    1991-01-01

    Two approaches to reducing optical aberrations of concave grating spectrographs have been used, holographically controlling the groove curvature and spacing and reshaping the optical substrate while ruling the grooves conventionally. The latter approach, slightly deforming an ellipsoidal grating blank, can lead to diffraction-limited performance at a single FUV wavelength. When such a grating is used in a slitted Rowland circle spectrograph, the result is an extremely efficient spectrograph with spectral resolving power of about 30,000 and low astigmatism. Optical fabrication technology has advanced to the point where these exotic surface gratings are becoming practical.

  16. Prime Focus Spectrograph for the Subaru telescope: massively multiplexed optical and near-infrared fiber spectrograph

    NASA Astrophysics Data System (ADS)

    Sugai, Hajime; Tamura, Naoyuki; Karoji, Hiroshi; Shimono, Atsushi; Takato, Naruhisa; Kimura, Masahiko; Ohyama, Youichi; Ueda, Akitoshi; Aghazarian, Hrand; de Arruda, Marcio Vital; Barkhouser, Robert H.; Bennett, Charles L.; Bickerton, Steve; Bozier, Alexandre; Braun, David F.; Bui, Khanh; Capocasale, Christopher M.; Carr, Michael A.; Castilho, Bruno; Chang, Yin-Chang; Chen, Hsin-Yo; Chou, Richard C. Y.; Dawson, Olivia R.; Dekany, Richard G.; Ek, Eric M.; Ellis, Richard S.; English, Robin J.; Ferrand, Didier; Ferreira, Décio; Fisher, Charles D.; Golebiowski, Mirek; Gunn, James E.; Hart, Murdock; Heckman, Timothy M.; Ho, Paul T. P.; Hope, Stephen; Hovland, Larry E.; Hsu, Shu-Fu; Hu, Yen-Shan; Huang, Pin Jie; Jaquet, Marc; Karr, Jennifer E.; Kempenaar, Jason G.; King, Matthew E.; Fèvre, Olivier Le; Mignant, David Le; Ling, Hung-Hsu; Loomis, Craig; Lupton, Robert H.; Madec, Fabrice; Mao, Peter; Marrara, Lucas Souza; Ménard, Brice; Morantz, Chaz; Murayama, Hitoshi; Murray, Graham J.; de Oliveira, Antonio Cesar; de Oliveira, Claudia Mendes; de Oliveira, Ligia Souza; Orndorff, Joe D.; de Paiva Vilaça, Rodrigo; Partos, Eamon J.; Pascal, Sandrine; Pegot-Ogier, Thomas; Reiley, Daniel J.; Riddle, Reed; Santos, Leandro; dos Santos, Jesulino Bispo; Schwochert, Mark A.; Seiffert, Michael D.; Smee, Stephen A.; Smith, Roger M.; Steinkraus, Ronald E.; Sodré, Laerte; Spergel, David N.; Surace, Christian; Tresse, Laurence; Vidal, Clément; Vives, Sebastien; Wang, Shiang-Yu; Wen, Chih-Yi; Wu, Amy C.; Wyse, Rosie; Yan, Chi-Hung

    2015-07-01

    The Prime Focus Spectrograph (PFS) is an optical/near-infrared multifiber spectrograph with 2394 science fibers distributed across a 1.3-deg diameter field of view at the Subaru 8.2-m telescope. The wide wavelength coverage from 0.38 μm to 1.26 μm, with a resolving power of 3000, simultaneously strengthens its ability to target three main survey programs: cosmology, galactic archaeology and galaxy/AGN evolution. A medium resolution mode with a resolving power of 5000 for 0.71 μm to 0.89 μm will also be available by simply exchanging dispersers. We highlight some of the technological aspects of the design. To transform the telescope focal ratio, a broad-band coated microlens is glued to each fiber tip. A higher transmission fiber is selected for the longest part of the cable system, optimizing overall throughput; a fiber with low focal ratio degradation is selected for the fiber-positioner and fiber-slit components, minimizing the effects of fiber movements and fiber bending. Fiber positioning will be performed by a positioner consisting of two stages of piezo-electric rotary motors. The positions of these motors are measured by taking an image of artificially back-illuminated fibers with the metrology camera located in the Cassegrain container; the fibers are placed in the proper location by iteratively measuring and then adjusting the positions of the motors. Target light reaches one of the four identical fast-Schmidt spectrograph modules, each with three arms. The PFS project has passed several project-wide design reviews and is now in the construction phase.

  17. Compact magnetograph

    NASA Technical Reports Server (NTRS)

    Title, A. M.; Gillespie, B. A.; Mosher, J. W.

    1982-01-01

    A compact magnetograph system based on solid Fabry-Perot interferometers as the spectral isolation elements was studied. The theory of operation of several Fabry-Perot systems, the suitability of various magnetic lines, signal levels expected for different modes of operation, and the optimal detector systems were investigated. The requirements that the lack of a polarization modulator placed upon the electronic signal chain was emphasized. The PLZT modulator was chosen as a satisfactory component with both high reliability and elatively low voltage requirements. Thermal control, line centering and velocity offset problems were solved by a Fabry-Perot configuration.

  18. The Dark Energy Spectroscopic Instrument (DESI): The Spectrographs

    NASA Astrophysics Data System (ADS)

    Edelstein, Jerry; DESI Collaboration

    2015-01-01

    The Dark Energy Spectroscopic Instrument (DESI) will conduct a large-area galaxy and quasi-stellar object redshift survey from the Mayall Telescope. It includes of ten spectrographs each recording 500 simultaneous object spectra collected by 5,000 positioned optical fibers in the focal plane of an 8-square degree telescope corrector. The spectrographs use dichroic filters to divide light into three optical channels that together cover the 360 - 980 nm pass band with a spectral resolution of 2,000 to 5,100. Each channel includes a volume phase holographic grating (VPHG) and a 5-element camera that images spectra onto a cryostatic detector. We describe the spectrograph design and predicted performance and the production of the first spectrograph's optical elements.

  19. Wavefront Sensing Using a Multi-Object Spectrograph (NIRSpec)

    NASA Technical Reports Server (NTRS)

    Dean, Bruce H.; Boucarut, Rene; Hadjimichael, Theo; Smith, Scott

    2004-01-01

    An analysis is presented that illustrates how the James Webb Space Telescope (JWST) fine-phasing process can be carried out using the Near-Infrared Spectrograph (NIRSpec) data collected at the science focal plane. The analysis considers a multi-plane diffraction model which properly accounts for the microshutter diffractive element placed at the first relay position of the spectrograph. Wavefront sensing results are presented based on data collected from the NASA Goddard Microshutter Testbed.

  20. X-ray spectrographic determination of cesium and rubidium

    USGS Publications Warehouse

    Axelrod, J.M.; Adler, I.

    1957-01-01

    An x-ray spectrographic method for the determination of rubidium and cesium was developed, using the internal-standard method and a four-channel flat-crystal spectrograph. The sensitivity is within 0.1% for cesia and 0.02% for rubidia; the precision is within 10% of the amount present. Results agree well with those obtained by flame photometry and by radio-activation.

  1. AAOmega: a multipurpose fiber-fed spectrograph for the AAT

    NASA Astrophysics Data System (ADS)

    Smith, Greg A.; Saunders, Will; Bridges, Terry; Churilov, Vladimir; Lankshear, Allan; Dawson, John; Correll, David; Waller, Lew; Haynes, Roger; Frost, Gabriella

    2004-09-01

    The AAOmega project replaces the two 2dF spectrographs, which are mounted on the top end of the Anglo Australian Telescope, with a bench mounted double beam spectrograph covering 370 to 950nm. The 2dF positioner, field plate tumbler mechanism, and fiber retractors will be retained. The new spectrograph will be fed by 392 fibers from either of the two 2dF field plates, or by the 512 fiber Spiral integral field unit, located at the Cassegrain focus. New instrument control electronics has also been designed to drive the spectrograph. Stability will be improved by locating the spectrograph off the telescope, but the 2df fibers must be extended to thirty-eight metres length. Despite this, using fibers with improved characteristics, increased pupil diameter, volume phase holographic (VPH) gratings with articulated cameras, and more efficient coatings on optics we achieve a minimum twofold increase in throughput. We will also fit larger (4k x 2k pixel) detectors. The spectrograph comprises: a F/3.15 Schmidt collimator, incorporating a dichroic beamsplitter; interchangeable VPH gratings; and articulating red and blue F/1.3 Schmidt cameras. The beamsplitter may be exchanged with others which cut off at different wavelengths. A full suite of VPH gratings are provided to cover resolution to 8000.

  2. The Kyoto Tridimensional Spectrograph II on Subaru and the University of Hawaii 88 in Telescopes

    NASA Astrophysics Data System (ADS)

    Sugai, H.; Hattori, T.; Kawai, A.; Ozaki, S.; Hayashi, T.; Ishigaki, T.; Ishii, M.; Ohtani, H.; Shimono, A.; Okita, Y.; Matsubayashi, K.; Kosugi, G.; Sasaki, M.; Takeyama, N.

    2010-01-01

    In order to investigate physical conditions of ionized gas in galaxies, as well as its kinematics, we have developed the Kyoto tridimensional spectrograph II. It is a multimode optical instrument, including integral field spectrograph (IFS) and Fabry-Perot imager modes. We have designed it compact so that we can mount it on 2 m class telescopes as well as on the 8.2 m Subaru telescope. Special care was taken to obtain high-quality calibrations in the IFS mode. In order to remove the chromatic aberration of micropupil images produced by a lenslet array, we have introduced a corrector lens system behind the lenslet array. The internal calibration system simulates the telescope optics so that the system provides micropupil images identical to those produced by the telescope. The rigidness of the instrument provides the positional stability of micropupil images. We have succeeded in test observations of all the modes on Subaru and the University of Hawaii 88 in (UH88) telescopes and have verified the performance of the instrument. This includes the instrument efficiencies as well as the effective sky background subtraction and the minimization of crosstalk effects in the IFS mode. In the IFS mode a spatial resolution of 0.4'' was obtained in good seeing conditions. Each of 37 × 37 lenslets subtends 0.1'' in Subaru's case. This samples the image size well. A wider field of view is emphasized in the case of UH88.

  3. Circumstellar discs in X/γ-ray binaries: first results from the Echelle spectrograph

    NASA Astrophysics Data System (ADS)

    Zamanov, R.; Stoyanov, K.; Martí, J.

    2016-01-01

    Here we report our first spectral observations of Be/X-ray and γ-ray binaries obtained with the new Echelle spectrograph of the National Astronomical Observatory Rozhen. For four objects (LSI+61°303, γ Cas, MWC 148, 4U 2206+54), we report the parameters and estimate the sizes of their circumstellar discs using different emission lines (Hα, Hβ, Hγ, HeI and FeII). For MWC 148, we find that the compact object goes deeply through the disc. The flank inflections of H&alpha& can be connected with inner ring formed at the periastron passage or radiation transfer effects. We point out an intriguing similarity between the optical emission lines of the γ-ray binary MWC 148 and the well known Be star γ Cas.

  4. Design and Construction of VUES: The Vilnius University Echelle Spectrograph

    NASA Astrophysics Data System (ADS)

    Jurgenson, Colby; Fischer, Debra; McCracken, Tyler; Sawyer, David; Giguere, Matt; Szymkowiak, Andrew; Santoro, Fernando; Muller, Gary

    2016-03-01

    In February 2014, the Yale Exoplanet Laboratory was commissioned to design, build, and deliver a high resolution (R=60,000) spectrograph for the 1.65m telescope at the Molėtai Astronomical Observatory. The observatory is operated by the Institute of Theoretical Physics and Astronomy at Vilnius University. The Vilnius University Echelle Spectrograph (VUES) is a white-pupil design that is fed via an octagonal fiber from the telescope and has an operational bandpass from 400nm to 880nm. VUES incorporates a novel modular optomechanical design that allows for quick assembly and alignment on commercial optical tables. This approach allowed the spectrograph to be assembled and commissioned at Yale using lab optical tables and then reassembled at the observatory on a different optical table with excellent repeatability. The assembly and alignment process for the spectrograph was reduced to a few days, allowing the spectrograph to be completely disassembled for shipment to Lithuania, and then installed at the observatory during a 10-day period in June of 2015.

  5. VIRUS: a massively replicated integral-field spectrograph for HET

    NASA Astrophysics Data System (ADS)

    Hill, Gary J.; MacQueen, Phillip J.; Tufts, Joseph R.; Kelz, Andreas; Roth, Martin M.; Altmann, Werner; Segura, Pedro; Gebhardt, Karl; Palunas, Povilas

    2006-06-01

    We present the design of, and the science drivers for, the Visible Integral-field Replicable Unit Spectrograph (VIRUS). This instrument is made up of 145 individually small and simple spectrographs, each fed by a fiber integral field unit. The total VIRUS-145 instrument covers ~30 sq. arcminutes per observation, providing integral field spectroscopy from 340 to 570 nm, simultaneously, of 35,670 spatial elements, each 1 sq. arcsecond on the sky. This corresponds to 15 million resolution elements per exposure. VIRUS-145 will be mounted on the Hobby-Eberly Telescope and fed by a new wide-field corrector with 22 arcminutes diameter field of view. VIRUS represents a new approach to spectrograph design, offering the science multiplex advantage of huge sky coverage for an integral field spectrograph, coupled with the engineering multiplex advantage of >100 spectrographs making up a whole. VIRUS is designed for the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) which will use baryonic acoustic oscillations imprinted on the large-scale distribution of Lyman-α emitting galaxies to provide unique constraints on the expansion history of the universe that can constrain the properties of dark energy.

  6. Construction of pre-slit system of Chinese SONG spectrograph

    NASA Astrophysics Data System (ADS)

    Gao, Pengfei; Hu, Zhongwen; Dai, Songxin

    2015-10-01

    The pre-slit system of Chinese SONG spectrograph is a multi-function unit. The main function is to direct the incoming light from the coudé path to the entrance slit of the spectrograph. The specific functions includes maintaining exit pupil stable, fast guiding and telescope focus corrections. The original optics of this pre-slit system were designed by Aarhus University in Denmark. We built the system and designed the software for it. This system holds a guide/slit-viewing camera, a pupil-viewing camera, two tip-tilt mirrors and its tip-tilt controllers. So it includes two sets of the fast-steering mirror systems applied to image tracking and correction. When this image tracking and correction systems is running, the real-time software algorithm will be presented and simulated simultaneously. From the images taken with camera, a closed loop signals are generated for the tip-tilt mirror to correct image motion. When the camera exposure time is 25ms,the correcting frequency of slit imge tip-tilt motion is about 30Hz. The correcting frequency of pupil imge tip-tilt motion is about 1Hz. In addition, a temperature control system surrounding the spectrograph is necessary to keep spectrograph at a constant temperature. The test results shows that the error is about +/-0.005°C in 69.4 hours. The results prove that the pre-slit system of Chinese SONG spectrograph is effective and feasible.

  7. Flight model performance of the integral field unit for the James Webb Space Telescope's near-infrared spectrograph

    NASA Astrophysics Data System (ADS)

    Purll, David J.; Lobb, Daniel R.; Barnes, Andrew R.; Talbot, R. Gordon; Rolt, Stephen; Robertson, David J.; Closs, Martin F.; te Plate, Maurice

    2010-07-01

    The Near Infrared Spectrograph (NIRSpec) developed by EADS Astrium GmbH for the European Space Agency (ESA) is a spectrograph covering the 0.6-5.0 μm waveband to fly on the James Webb Space Telescope (JWST). NIRSpec will be primarily operated as a multi-object spectrograph but also includes an integral field unit (IFU) allowing a 3×3 arcsec field of view to be sampled continuously with 0.1 arcsec spatial resolution. The IFU, based on an advanced image slicer concept, is a very compact athermal unit made of aluminium. It contains three 30-element monolithic mirror arrays forming slicer, pupil and slit mirrors, and single-surface image relay and plane fold mirrors, produced using 5-axis diamond-machining techniques. Many of the mirrors have complex surfaces like toric sections with 3rd-order corrections in order to achieve the required performance within a small allowed volume, and could only have been fabricated with the most advanced free-form machining. The mechanical design accommodates the differential expansion between the aluminium IFU and its titanium parent assembly across a 250K drop to operating temperature using an isostatic mounting system. This paper presents the development of the IFU from the design and diamond-machining techniques to the optical and cryogenic testing of the assembled flight model unit.

  8. Compaction behavior of roller compacted ibuprofen.

    PubMed

    Patel, Sarsvatkumar; Kaushal, Aditya Mohan; Bansal, Arvind Kumar

    2008-06-01

    The effect of roller compaction pressure on the bulk compaction of roller compacted ibuprofen was investigated using instrumented rotary tablet press. Three different roller pressures were utilized to prepare granules and Heckel analysis, Walker analysis, compressibility, and tabletability were performed to derive densification, deformation, course of volume reduction and bonding phenomenon of different pressure roller compacted granules. Nominal single granule fracture strength was obtained by micro tensile testing. Heckel analysis indicated that granules prepared using lower pressure during roller compaction showed lower yield strength. The reduction in tabletability was observed for higher pressure roller compacted granules. The reduction in tabletability supports the results of granule size enlargement theory. Apart from the granule size enlargement theory, the available fines and relative fragmentation during compaction is responsible for higher bonding strength and provide larger areas for true particle contact at constant porosity for lower pressure roller compacted granules. Overall bulk compaction parameters indicated that granules prepared by lower roller compaction pressure were advantageous in terms of tabletability and densification. Overall results suggested that densification during roller compaction affects the particle level properties of specific surface area, nominal fracture strength, and compaction behavior. PMID:18280716

  9. Astro-comb calibration of an Echelle Spectrograph

    NASA Astrophysics Data System (ADS)

    Li, C.-H.; Phillips, D. F.; Glenday, A. G.; Benedick, A. J.; Chang, G.; Chen, L.-J.; Cramer, C.; Furesz, G.; Kärtner, F. X.; Sasselov, D.; Szentgyorgyi, A.; Walsworth, R. L.

    2010-07-01

    We describe recent work calibrating a cross-dispersed spectrograph with an "astro-comb" i.e., a high repetition rate, octave spanning femtosecond laser frequency comb; and a filter cavity suppressing laser modes to match the resolution of the spectrograph. Our astro-comb provides ~1500 evenly spaced (~0.6 A) calibration lines of roughly 100 nW per line between 7800 and 8800 Angstroms. The calibration lines of the laser are stabilized to atomic clocks which can be referenced to GPS providing intrinsic stability of the source laser below 1 cm/s in stellar radial velocity sensitivity, as well as long term stability and reproducibility over years. We present calibration of the TRES spectrograph at the 1.5 m telescope at the Fred L Whipple Observatory below 1 m/s radial velocity sensitivity in six orders from 7800-8800 A.

  10. Sky background subtraction with fiber-fed spectrographs

    NASA Astrophysics Data System (ADS)

    Puech, M.; Rodrigues, M.; Yang, Y.; Flores, H.; Royer, F.; Disseau, K.; Gonçalves, T.; Hammer, F.; Cirasuolo, M.; Evans, C. J.; Li Causi, G.; Maiolino, R.; Melo, C.

    2014-08-01

    Fiber-fed spectrographs can now have throughputs equivalent to slit spectrographs. However, the sky subtraction accuracy that can be reached on such instruments has often been pinpointed as one of their major issues, in relation to difficulties in scattered light and flat-field corrections or throughput losses associated with fibers. Using technical time observations with FLAMES-GIRAFFE, two observing techniques, namely dual staring and cross beam switching modes, were tested and the resulting sky subtraction accuracy reached in both cases was quantified. Results indicate that an accuracy of 0.6% on the sky subtraction can be reached, provided that the cross beam switching mode is used. This is very encouraging regarding the detection of very faint sources with future fiber-fed spectrographs such as VLT/MOONS or E-ELT/MOSAIC.

  11. The construction, alignment, and installation of the VIRUS spectrograph

    NASA Astrophysics Data System (ADS)

    Tuttle, Sarah E.; Hill, Gary J.; Lee, Hanshin; Vattiat, Brian; Noyola, Eva; Drory, Niv; Cornell, Mark; Peterson, Trent; Chonis, Taylor; Allen, Richard; Dalton, Gavin; DePoy, Darren; Edmonston, Doug; Fabricius, Maximillian; Haynes, Dionne; Kelz, Andreas; Landriau, Martin; Lesser, Michael; Leach, Bob; Marshall, Jennifer; Murphy, Jeremy; Perry, David; Prochaska, Travis; Ramsey, Jason; Savage, Richard

    2014-07-01

    VIRUS is the massively replicated fiber-fed spectrograph being built for the Hobby-Eberly Telescope to support HETDEX (the Hobby-Eberly Telescope Dark Energy Experiment). The instrument consists of 156 identical channels, fed by 34,944 fibers contained in 78 integral field units, deployed in the 22 arcminute field of the upgraded HET. VIRUS covers 350-550nm at R ≍ 700 and is built to target Lyman α emitters at 1.9 < z < 3.5 to measure the evolution of dark energy. Here we present the assembly line construction of the VIRUS spectrographs, including their alignment and plans for characterization. We briefly discuss plans for installation on the telescope. The spectrographs are being installed on the HET in several stages, and the instrument is due for completion by the end of 2014.

  12. Multiple object fiber optics spectrograph feed for the Hale telescope

    NASA Technical Reports Server (NTRS)

    Tubbs, E. F.; Goss, W. C.; Cohen, J. G.

    1982-01-01

    The preliminary design for a computer-controlled fiber-optics feed linking the 5-m Hale telescope at Palomar Observatory to the entrance slit of an astronomical spectrograph is presented. A 76-mm square field will be divided into ten strips containing two movable fibers each; the fibers can be moved by stepper-motor-driven lead screws to any position on the strip. The device is designed to allow the simultaneous spectrographic observation of many astronomical objects in a small angular field. A prototype feed using two fibers and manually commanded digital control is described in detail. Test observations of two bright O stars made in April, 1981 using the prototype with the Hale telescope are considered sufficiently positive to warrant construction of the 20-fiber feed, which would enhance the spectrographic-survey effectiveness of the telescope by a factor of ten.

  13. Compact Reactor

    SciTech Connect

    Williams, Pharis E.

    2007-01-30

    Weyl's Gauge Principle of 1929 has been used to establish Weyl's Quantum Principle (WQP) that requires that the Weyl scale factor should be unity. It has been shown that the WQP requires the following: quantum mechanics must be used to determine system states; the electrostatic potential must be non-singular and quantified; interactions between particles with different electric charges (i.e. electron and proton) do not obey Newton's Third Law at sub-nuclear separations, and nuclear particles may be much different than expected using the standard model. The above WQP requirements lead to a potential fusion reactor wherein deuterium nuclei are preferentially fused into helium nuclei. Because the deuterium nuclei are preferentially fused into helium nuclei at temperatures and energies lower than specified by the standard model there is no harmful radiation as a byproduct of this fusion process. Therefore, a reactor using this reaction does not need any shielding to contain such radiation. The energy released from each reaction and the absence of shielding makes the deuterium-plus-deuterium-to-helium (DDH) reactor very compact when compared to other reactors, both fission and fusion types. Moreover, the potential energy output per reactor weight and the absence of harmful radiation makes the DDH reactor an ideal candidate for space power. The logic is summarized by which the WQP requires the above conditions that make the prediction of DDH possible. The details of the DDH reaction will be presented along with the specifics of why the DDH reactor may be made to cause two deuterium nuclei to preferentially fuse to a helium nucleus. The presentation will also indicate the calculations needed to predict the reactor temperature as a function of fuel loading, reactor size, and desired output and will include the progress achieved to date.

  14. Ceramic powder compaction

    SciTech Connect

    Glass, S.J.; Ewsuk, K.G.; Mahoney, F.M.

    1995-12-31

    With the objective of developing a predictive model for ceramic powder compaction we have investigated methods for characterizing density gradients in ceramic powder compacts, reviewed and compared existing compaction models, conducted compaction experiments on a spray dried alumina powder, and conducted mechanical tests and compaction experiments on model granular materials. Die filling and particle packing, and the behavior of individual granules play an important role in determining compaction behavior and should be incorporated into realistic compaction models. These results support the use of discrete element modeling techniques and statistical mechanics principals to develop a comprehensive model for compaction, something that should be achievable with computers with parallel processing capabilities.

  15. The AVES adaptive optics spectrograph for the VLT: status report

    NASA Astrophysics Data System (ADS)

    Pallavicini, Roberto; Delabre, Bernard; Pasquini, Luca; Zerbi, Filippo M.; Bonanno, Giovanni; Comari, Maurizio; Conconi, Paolo; Mazzoleni, Ruben; Santin, Paolo; Damiani, Francesco; Di Marcantonio, Paolo; Franchini, Mariagrazia; Spano, Paolo; Bonifacio, P.; Catalano, Santo; Molaro, Paolo P.; Randich, S.; Rodono, Marcello

    2003-03-01

    We report on the status of AVES, the Adaptive-optics Visual Echelle Spectrograph proposed for the secondary port of the Nasmyth Adaptive Optics System (NAOS) recently installed at the VLT. AVES is an intermediate resolution (R ≍ 16,000) high-efficiency fixed- format echelle spectrograph which operates in the spectral band 500 - 1,000 nm. In addition to a high intrinsic efficiency, comparable to that of ESI at Keck II, it takes advantage of the adaptive optics correction provided by NAOS to reduce the sky and detector contribution in background-limited observations of weak sources, thus allowing a further magnitude gain with respect to comparable non-adaptive optics spectrographs. Simulations show that the instrument will be capable of reaching a magnitude V = 22.5 at S/N > 10 in two hours, two magnitudes weaker than GIRAFFE at the same resolution and 3 magnitudes weaker than the higher resolution UVES spectrograph. Imaging and coronographic functions have also been implemented in the design. We present the results of the final design study and we dicuss the technical and operational issues related to its implementation at the VLT as a visitor instrument. We also discuss the possibility of using a scaled-up non-adaptive optics version of the same design as an element of a double- or triple-arm intermediate-resolution spectrograph for the VLT. Such an option looks attractive in the context of a high-efficiency large-bandwidth (320 - 1,500 nm) spectrograph ("fast-shooter") being considered by ESO as a 2nd-generation VLT instrument.

  16. Optical design of the SuMIRe/PFS spectrograph

    NASA Astrophysics Data System (ADS)

    Pascal, Sandrine; Vives, Sébastien; Barkhouser, Robert; Gunn, James E.

    2014-07-01

    The SuMIRe Prime Focus Spectrograph (PFS), developed for the 8-m class SUBARU telescope, will consist of four identical spectrographs, each receiving 600 fibers from a 2394 fiber robotic positioner at the telescope prime focus. Each spectrograph includes three spectral channels to cover the wavelength range [0.38-1.26] um with a resolving power ranging between 2000 and 4000. A medium resolution mode is also implemented to reach a resolving power of 5000 at 0.8 um. Each spectrograph is made of 4 optical units: the entrance unit which produces three corrected collimated beams and three camera units (one per spectral channel: "blue, "red", and "NIR"). The beam is split by using two large dichroics; and in each arm, the light is dispersed by large VPH gratings (about 280x280mm). The proposed optical design was optimized to achieve the requested image quality while simplifying the manufacturing of the whole optical system. The camera design consists in an innovative Schmidt camera observing a large field-of-view (10 degrees) with a very fast beam (F/1.09). To achieve such a performance, the classical spherical mirror is replaced by a catadioptric mirror (i.e meniscus lens with a reflective surface on the rear side of the glass, like a Mangin mirror). This article focuses on the optical architecture of the PFS spectrograph and the perfornance achieved. We will first described the global optical design of the spectrograph. Then, we will focus on the Mangin-Schmidt camera design. The analysis of the optical performance and the results obtained are presented in the last section.

  17. Extreme Precision Environmental Control for Next Generation Radial Velocity Spectrographs

    NASA Astrophysics Data System (ADS)

    Stefansson, Gudmundur K.; Hearty, Fred; Levi, Eric; Robertson, Paul; Mahadevan, Suvrath; Bender, Chad; Nelson, Matt; Halverson, Samuel

    2015-12-01

    Extreme radial velocity precisions of order 10cm/s will enable the discoveries of Earth-like planets around solar-type stars. Temperature and pressure variations inside a spectrograph can lead to thermomechanical instabilities in the optics and mounts, and refractive index variations in both the optical elements as well as the surrounding air. Together, these variations can easily induce instrumental drifts of several tens to hundreds of meters per second. Enclosing the full optical train in thermally stabilized high-vacuum environments minimizes such errors. In this talk, I will discuss the Environmental Control System (ECS) for the Habitable Zone Planet Finder (HPF) spectrograph: a near infrared (NIR) facility class instrument we will commission at the Hobby Eberly Telescope in 2016. The ECS will maintain the HPF optical bench stable at 180K at the sub milli-Kelvin level on the timescale of days, and at the few milli-Kelvin level over months to years. The entire spectrograph is kept under high-quality vacuum (<10-6 Torr), and environmental temperature fluctuations are compensated for with an actively controlled radiation shield outfitted with custom feedback electronics. High efficiency Multi-Layer Insulation (MLI) blankets, and a passive external thermal enclosure further isolate the optics from ambient perturbations. This environmental control scheme is versatile, suitable to stabilize both next generation NIR, and optical spectrographs. I will show how we are currently testing this control system for use with our design concept of the Extreme Precision Doppler Spectrograph (EPDS), the next generation optical spectrograph for the WIYN 3.5m telescope. Our most recent results from full-scale stability tests will be presented.

  18. National Student Solar Spectrograph Competition Overview and Results

    NASA Astrophysics Data System (ADS)

    Des Jardins, Angela C.; Larimer, R.; Shaw, J. A.; Kankelborg, C.; Palmer, C.; Key, J. S.; Nakagawa, W.; Springer, L.; Knighton, W.; Repasky, K. S.; Pust, N. J.; Babbitt, W.; Jaeggli, S. A.; Hobish, M. K.; Wilson, E. W.; Anderson, M.; Boger, J.; McCrady, N.; Naylor, J.; Turcotte, S.; Lines, T.; Strobel, N.; Cooper, W.; Darke, R.; Head, R.; Kimball, D.; Kissel, G.; Buck, K.; Lawrence, L.; Wragg, J.; Runyon, C. J.; Spacher, P.; Dumitriu, I.; Nollenberg, J. G.; Estaban, R.

    2013-07-01

    The yearly National Student Solar Spectrograph Competition (NSSSC) is Montana Space Grant Consortium's Education and Public Outreach (EP/O) Program for NASA's Interface Region Imaging Spectrograph (IRIS) mission. The NSSSC is designed to give institutions with less aerospace activity such as Minority Serving Institutions and Community Colleges an opportunity for hands on real world research experience. The NSSSC provides students from across the country the opportunity to work as part of an undergraduate interdisciplinary team to design, build and test a ground based solar spectrograph. Over the course of nine months, teams come up with their own science goals and then build an instrument to collect data in support of their goals. Teams then travel to Bozeman, MT to demonstrate their instruments and present their results in a competitive science fair environment. This poster will present the 2012-2013 competition results.Abstract (2,250 Maximum Characters): The yearly National Student Solar Spectrograph Competition (NSSSC) is Montana Space Grant Consortium's Education and Public Outreach (EP/O) Program for NASA's Interface Region Imaging Spectrograph (IRIS) mission. The NSSSC is designed to give institutions with less aerospace activity such as Minority Serving Institutions and Community Colleges an opportunity for hands on real world research experience. The NSSSC provides students from across the country the opportunity to work as part of an undergraduate interdisciplinary team to design, build and test a ground based solar spectrograph. Over the course of nine months, teams come up with their own science goals and then build an instrument to collect data in support of their goals. Teams then travel to Bozeman, MT to demonstrate their instruments and present their results in a competitive science fair environment. This poster will present the 2012-2013 competition results.

  19. The current status of the UK-FMOS spectrograph

    NASA Astrophysics Data System (ADS)

    Tosh, Ian A.; Woodhouse, Guy F.; Froud, Tim; Dowell, Allan; Patel, Mukesh; Wallner, Mattias; Lewis, Ian J.; Dalton, Gavin B.; Holmes, Alan; Brooks, Barney; Band, Cyril; Bonfield, David G.; Murray, Graham J.; Robertson, David J.; Dipper, Nigel A.

    2004-09-01

    FMOS is a near-IR OH-suppressed multi-fibre fed spectrograph for the Subaru telescope. The spectrograph will accept 200 optical fibres from the ECHIDNA positioner system at the 30arcmin Prime focus of the telescope. We will describe the recent activities here in the UK in progressing the instrument from its conceptual phase through detailed design and into manufacture. A variety of technical areas will be described including: the opto-mechanical system design and construction, development of the HAWAII-II detector control system, the thermal system design & control and OH suppression techniques.

  20. An integral field spectrograph for SNAP supernova studies

    SciTech Connect

    Ealet, Anne; Prieto, E.; Bonissent, A.; Malina, R.; Basa, S.; LeFevre, O.; Mazure, A.; Tarle, G.; Akerlof, C.W.; Aldering, G.; Amidei, D.E.; Astier, P.; Baden, A.R.; Bebek, C.; Bergstrom, L.; Bernstein, G.M.; Bower, C.R.; Campbell, M.; Carithers Jr., W.C.; Commins, E.D.; Curtis, D.W.; Deustua, S.E.; Edwards, W.R.; Ellis, R.S.; Fruchter, A.; Frye, B.L.; Genat, J.; Goldhaber, G.; Goobar, A.; Goodman, J.A.; Graham, J.R.; Hardin, D.; Harris, S.E.; Harvey, P.R.; Heetderks, H.D.; Honeycutt, R.; Holland, S.E.; Hook, I.; Huterer, D.; Kasen, D.N.; Kim, A.G.; Knop, R.A.; Lafever, R.; Lampton, M.L.; Levi, M.E.; Levin, D.S.; Levy, J.M.; Lidman, C.; Lin, R.P.; Linder, E.V.; Loken, S.C.; McKay, T.; McKee, S.P.; Metzger, M.R.; Miquel, R.; Mourao, A.; Mufson, S.; Musser, J.A.; Nugent, P.E.; Pain, R.; Pankow, D.H.; Pennypacker, C.R.; Perlmutter, S.; Refregier, A.; Rich, J.; Robinson, K.E.; Schahmaneche, K.; Schubnell, M.S.; Spadafora, A.; Smoot, G.F.; Sullivan, G.W.; Tomasch, A.D.; SNAP Collaboration

    2002-07-29

    A well-adapted spectrograph concept has been developed for the SNAP (SuperNova/Acceleration Probe) experiment. The goal is to ensure proper identification of Type Ia supernovae and to standardize the magnitude of each candidate by determining explosion parameters. An instrument based on an integral field method with the powerful concept of imager slicing has been designed and is presented in this paper. The spectrograph concept is optimized to have very high efficiency and low spectral resolution (R {approx} 100), constant through the wavelength range (0.35-1.7{micro}m), adapted to the scientific goals of the mission.

  1. Image Slicer for the Subaru Telescope High Dispersion Spectrograph

    NASA Astrophysics Data System (ADS)

    Tajitsu, Akito; Aoki, Wako; Yamamuro, Tomoyasu

    2012-08-01

    We report on the design, manufacturing, and performance of the image slicer for the High Dispersion Spectrograph on Subaru Telescope. This instrument is a Bowen-Walraven type image slicer, providing five images of 0."3 × 1."5 with a resolving power of R = λ/δλ = 110000. The resulting resolving power and line profiles have been investigated in detail, including estimates of the defocusing effect on the resolving power. The throughput in a wavelength range of from 400 to 700 nm is higher than 80%, thereby improving the efficiency of the spectrograph under a seeing condition of 0."7 by a factor of 1.8.

  2. A soft x-ray octadecyl hydrogen maleate crystal spectrograph

    SciTech Connect

    Fan, P.Z.; Fill, E.E.; Tietang, G.

    1996-03-01

    A crystal spectrograph is described which can be used to investigate laser-produced plasmas in the region of soft x rays at wavelengths of up to 60 A. The spectrograph uses an octadecyl hydrogen maleate crystal with a 2{ital d} of 63.5 A, combined with a very thin carbon filter (3000 A thick). As examples of its application, soft x-ray spectra in the range of 43{endash}51 A from laser plasmas of Si and Cu are presented. A spectral resolution of {lambda}/{Delta}{lambda}=1100 is deduced from the spectra. {copyright} {ital 1996 American Institute of Physics.}

  3. A new fiber slit assembly for the FOCES spectrograph

    NASA Astrophysics Data System (ADS)

    Kellermann, Hanna; Grupp, Frank; Brucalassi, Anna; Lang-Bardl, Florian; Franik, Christian; Hopp, Ulrich; Bender, Ralf

    2015-09-01

    After successful operation at the Calar Alto telescope until 2009, and extensive lab tests at the Munich University Observatory the high resolution Échelle spectrograph FOCES (Fiber Optics Cassegrain Échelle Spectrograph) is now about to be reinstalled at the 2 m Wendelstein Observatory in the German Alps. For this new phase of operation FOCES will be equipped with new components that will improve time stability and wavelength calibration. With these modifications FOCES will meet the requirements for performing precision radial velocity measurements on a competitive level. One of the key features of the upgraded spectrograph is the new calibration system, which uses a laser frequency comb as reference light source. Another aspect is the possibility to perform simultaneous wavelength calibration, while recording science data. For this purpose a new 4-fiber slit has been developed, which opens up the possibility to feed light from different sources at the same time through the entrance slit of the spectrograph. We present a detailed characterization of this new device, based on the results of extensive lab tests performed at the Munich University Observatory.

  4. Galactic Archaeology with the Subaru Prime Focus Spectrograph

    NASA Astrophysics Data System (ADS)

    Chiba, Masashi; Cohen, Judith; Wyse, Rosemary F. G.

    2016-08-01

    We present an overview of our Galactic Archaeology (GA) survey program with the Prime Focus Spectrograph (PFS) for Subaru. Following successful design reviews, the instrument is now under construction with first light anticipated in 2018. Main characteristics of PFS and the science goals in our PFS/GA program are described.

  5. X-shooter near-IR spectrograph arm realisation

    NASA Astrophysics Data System (ADS)

    Navarro, Ramon; Elswijk, Eddy; Tromp, Niels; ter Horst, Rik; Horrobin, Matthew; Vernet, Joel; Finger, Gert; Groot, Paul; Kaper, Lex

    2008-07-01

    X-shooter is a new high-efficiency spectrograph observing the complete spectral range of 300-2500 nm in a single exposure, with a spectral resolving power R>5000. The instrument will be located at the Cassegrain focus of one of the VLT UTs and consists of three spectrographs: UV, VIS and Near-IR. This paper addresses the design, hardware realization and performance of the Near-IR spectrograph of the X-Shooter instrument and its components. Various optical, mechanical and cryogenic manufacturing and verification techniques are discussed. The cryogenic performance of replicated light weight gratings is presented. Bare aluminium mirrors are produced and polished to optical quality to preserve high shape accuracy at cryogenic conditions. Their manufacturing techniques and performance are both discussed. The cryogenic collimator and dispersion boxes, on which the optical components are mounted, feature integrated baffles for improved stiffness and integrated leaf springs to reduce tension on optical components, thereby challenging 5 axis simultaneous CNC milling capabilities. ASTRON Extreme Light Weighting is used for a key component to reduce the flexure of the cryogenic system; some key numbers and unique manufacturing experience for this component are presented. The method of integrated system design at cryogenic working temperatures and the resulting alignment-free integration are evaluated. Finally some key lab test results for the complete NIR spectrograph are presented.

  6. Detector Arrays for the James Webb Near Infrared Spectrograph

    NASA Technical Reports Server (NTRS)

    Rauscher, Bernard J.

    2009-01-01

    NASA Goddard Space Flight Center is delivering the detector subsystem for the James Webb Space Telescope (JWST) Near Infrared Spectrograph (NIRSpec). Of all JWST instruments, NIRSpec has the most stringent detector requirements. In this poster, we describe recent performance testing results and relate them to NIRSpec's science requirements.

  7. Miniaturized high-resolution mass/charge spectrograph /design study/

    NASA Technical Reports Server (NTRS)

    Taylor, L. H.

    1969-01-01

    Use of a double-focusing mass/charge spectrograph weighing less than 25 pounds is feasible for solar wind experiments. Instrument has a parallel-plate energy filter between the ion source and the double focusing units which alleviates the problem of designing an ion source of small energy spread.

  8. Efficient and affordable catadioptric spectrograph designs for 4MOST and Hector

    NASA Astrophysics Data System (ADS)

    Saunders, Will

    2014-08-01

    Spectrograph costs have become the limiting factor in multiplexed fiber-based spectroscopic instruments, because tens of millions of resolution elements (spectral x spatial) are now required. Catadioptric (Schmidt-like) designs allow faster cameras and hence reduced detector costs, and recent advances in aspheric lens production make the overall optics costs competitive with transmissive designs. Classic Schmidt designs suffer from obstruction losses caused by the detector being within the beam. A new catadioptric design puts the detector close to the spectrograph pupil, and hence largely in the shadow of the telescope top-end obstruction. The throughput is competitive with the best transmissive designs, and much better in the Blue, where it is usually most valuable. The design also has milder aspheres and is more compact than classic Schmidts, and avoids most of their operational difficulties. The fast cameras mean that with 15micron pixels, the PSF sampling is close to the Nyquist limit; this minimises the effects of read-noise, which for sky-limited observations, far outweighs any difference in throughput. It does introduce pixellation penalties; these are investigated and found to be modest. For 4MOST, low and high resolution designs are presented, with 300mm beams, 3 arms with f/1.3 cameras, and standard 61mm x 61mm detectors. Coverage is 380-930nm at R=5000-7000, or R~20000 in three smaller ranges. A switchable design is also presented. For Hector, a design is presented with 2 arms, 380-930nm coverage, and R=3000-4500; a 4- armed design with smaller beam-size and detectors is also presented. The designs are costed, and appear to represent excellent value.

  9. Compact high-resolution VIS/NIR hyperspectral sensor

    NASA Astrophysics Data System (ADS)

    Hyvärinen, Timo; Herrala, Esko; Procino, Wes; Weatherbee, Oliver

    2011-06-01

    Current hyperspectral imagers are either bulky with good performance, or compact with only moderate performance. This paper presents a new hyperspectral technology which overcomes this drawback, and makes it possible to integrate extremely compact and high performance push-broom hyperspectral imagers for Unmanned Aerial Vehicles (UAV) and other demanding applications. Hyperspectral imagers in VIS/NIR, SWIR, MWIR and LWIR spectral ranges have been implemented. This paper presents the measured performance attributes for a VIS/NIR imager which covers 350 to 1000 nm with spectral resolution of 3 nm. The key innovation is a new imaging spectrograph design which employs both transmissive and reflective optics in order to achieve high light throughput and large spatial image size in an extremely compact format. High light throughput is created by numerical aperture of F/2.4 and high diffraction efficiency. Image distortions are negligible, keystone being <2 um and smile 0.13 nm across the full focal plane image size of 24 mm (spatially) x 6 m (spectrally). The spectrograph is integrated with an advanced camera which provides 1300 spatial pixels and image rate of 160 Hz. A higher resolution version with 2000 spatial pixels will produce up to 100 images/s. The camera achieves, with spectral binning, an outstanding signal-to-noise ratio of 800:1, orders of magnitude higher than any current compact VIS/NIR imager. The imager weighs only 1.4 kg, including fore optics, imaging spectrograph with shutter and camera, in a format optimized for installation in small payload compartments and gimbals. In addition to laboratory characterization, results from a flight test mission are presented.

  10. Volume phase holographic gratings for the Subaru Prime Focus Spectrograph: performance measurements of the prototype grating set

    NASA Astrophysics Data System (ADS)

    Barkhouser, Robert H.; Arns, James; Gunn, James E.

    2014-08-01

    The Prime Focus Spectrograph (PFS) is a major instrument under development for the 8.2 m Subaru telescope on Mauna Kea. Four identical, fixed spectrograph modules are located in a room above one Nasmyth focus. A 55 m fiber optic cable feeds light into the spectrographs from a robotic fiber positioner mounted at the telescope prime focus, behind the wide field corrector developed for Hyper Suprime-Cam. The positioner contains 2400 fibers and covers a 1.3 degree hexagonal field of view. Each spectrograph module will be capable of simultaneously acquiring 600 spectra. The spectrograph optical design consists of a Schmidt collimator, two dichroic beamsplitters to separate the light into three channels, and for each channel a volume phase holographic (VPH) grating and a dual- corrector, modified Schmidt reimaging camera. This design provides a 275 mm collimated beam diameter, wide simultaneous wavelength coverage from 380 nm to 1.26 µm, and good imaging performance at the fast f/1.1 focal ratio required from the cameras to avoid oversampling the fibers. The three channels are designated as the blue, red, and near-infrared (NIR), and cover the bandpasses 380-650 nm (blue), 630-970 nm (red), and 0.94-1.26 µm (NIR). A mosaic of two Hamamatsu 2k×4k, 15 µm pixel CCDs records the spectra in the blue and red channels, while the NIR channel employs a 4k×4k, substrate-removed HAWAII-4RG array from Teledyne, with 15 µm pixels and a 1.7 µm wavelength cutoff. VPH gratings have become the dispersing element of choice for moderate-resolution astronomical spectro- graphs due their potential for very high diffraction efficiency, low scattered light, and the more compact instru- ment designs offered by transmissive dispersers. High quality VPH gratings are now routinely being produced in the sizes required for instruments on large telescopes. These factors made VPH gratings an obvious choice for PFS. In order to reduce risk to the project, as well as fully exploit the performance

  11. Calibration of an Astrophysical Spectrograph with an Astro-comb

    NASA Astrophysics Data System (ADS)

    Phillips, David F.; Glenday, Alex; Li, Chih-Hao; Cramer, Claire; Korzennik, Sylvain; Noah Chang, Guoqing; Chen, Li-Jin; Benedick, Andrew; Kaertner, Franz X.; Sasselov, Dimitar; Szentgyorgyi, Andrew; Walsworth, Ronald L.

    2010-03-01

    Searches for extrasolar planets using the periodic Doppler shift of stellar lines are approaching Earth-like planet sensitivity. To find a 1-Earth-mass planet in an Earth-like orbit, an order of magnitude improvement in state-of-the-art radial velocity spectroscopy is necessary. An astro-comb, the combination of an ocatve-spanning laser frequency comb with a Fabry-Perot cavity, producing evenly spaced frequency markers with the potential for large wavelength coverage is a promising avenue towards improved wavelength calibration. Here we demonstrate the calibration of a high-resolution astrophysical spectrograph below the 1 m/s level in the 800-900 nm spectral band using an octave-spanning Ti:Sapphire laser and an ultra-low dispersion Fabry-Perot filter cavity adjusted for a mode spacing of approximately 31 GHz. Modeling of spectrograph response function and overall system stability and reproducibility will be described.

  12. VIRUS: A hugely replicated integral field spectrograph for HETDEX

    NASA Astrophysics Data System (ADS)

    Hill, Gary J.; MacQueen, Phillip J.; Palunas, Povilas; Kelz, Andreas; Roth, Martin M.; Gebhardt, Karl; Grupp, Frank

    2006-06-01

    We present the visible integral-field replicable unit spectrograph (VIRUS), the basis of the Hobby-Eberly telescope dark energy experiment (HETDEX); a survey of a 5 Gpc 3 volume at 1.8 < z < 3.7 that will constrain the evolution of dark energy. VIRUS consists of 145 copies of a simple unit spectrograph, deployed on the HET. Industrial replication will allow VIRUS to be built quickly, at considerable cost-savings, with substantial risk-mitigation, compared to conventional instruments. VIRUS will cover 30 sq. arcmin per observation and detect 14 million resolution elements per exposure, an order of magnitude larger than existing instruments. VIRUS can complete HETDEX in about 100 nights observing.

  13. WUVS spectrographs of World Space Observatory - Ultraviolet project

    NASA Astrophysics Data System (ADS)

    Savanov, Igor; Sachkov, Mikhail; Shustov, Boris M.; Shugarov, Andrey

    2016-07-01

    WSO-UV (World Space Observatory - Ultraviolet) project is an international space observatory designed for observations in the UV (115 - 320 nm). It includes a 170 cm aperture telescope capable of high-resolution spectroscopy, long slit low-resolution spectroscopy and deep UV and optical imaging. WUVS - the set of three ultraviolet spectrographs are regarded as the main instrument of «Spektr -UF» space mission. The spectrographs unit includes three channels and is intended for acquisition of spectrums of high (R=50000) and low (R=1000) resolution of the observed objects in the electromagnetic radiation's ultraviolet range (115-310 nm). We present the design philosophy of WUVS and summarize its key characteristics. We shall present the main properties of WUVS new structure and current status of its mockups and prototypes manufacturing.

  14. The infrared spectrograph during the SIRTF pre-definition phase

    NASA Technical Reports Server (NTRS)

    Houck, James R.

    1988-01-01

    A test facility was set up to evaluate back-illuminated impurity band detectors constructed for an infrared spectrograph to be used on the Space Infrared Telescope Facility (SIRTF). Equipment built to perform the tests on these arrays is described. Initial tests have been geared toward determining dark current and read noise for the array. Four prior progress reports are incorporated into this report. They describe the first efforts in the detector development and testing effort; testing details and a new spectrograph concept; a discussion of resolution issues raised by the new design; management activities; a review of computer software and testing facility hardware; and a review of the preamplifier constructed as well as a revised schematic of the detector evaluation facility.

  15. The Imaging Ultraviolet Spectrograph (IUVS) for the MAVEN Mission

    NASA Astrophysics Data System (ADS)

    McClintock, William E.; Schneider, Nicholas M.; Holsclaw, Gregory M.; Clarke, John T.; Hoskins, Alan C.; Stewart, Ian; Montmessin, Franck; Yelle, Roger V.; Deighan, Justin

    2015-12-01

    The Imaging Ultraviolet Spectrograph (IUVS) is one of nine science instruments aboard the Mars Atmosphere and Volatile and EvolutioN (MAVEN) spacecraft. MAVEN, launched in November 18, 2013 and arriving at Mars in September 2014, is designed to explore the planet's upper atmosphere and ionosphere and examine their interaction with the solar wind and solar ultraviolet radiation. IUVS is one of the most powerful spectrographs sent to another planet, with several key capabilities: (1) separate Far-UV & Mid-UV channels for stray light control, (2) a high resolution echelle mode to resolve deuterium and hydrogen emission, (3) internal instrument pointing and scanning capabilities to allow complete mapping and nearly-continuous operation, and (4) optimization for airglow studies.

  16. Metrology camera system of prime focus spectrograph for Subaru telescope

    NASA Astrophysics Data System (ADS)

    Wang, Shiang-Yu; Chou, Chueh-Yi; Chang, Yin-Chang; Huang, Pin-Jie; Hu, Yen-Sang; Chen, Hsin-Yo; Tamura, Naoyuki; Takato, Naruhisa; Ling, Hung-Hsu; Gunn, James E.; Karr, Jennifer; Yan, Chi-Hung; Mao, Peter; Ohyama, Youichi; Karoji, Hiroshi; Sugai, Hajime; Shimono, Atsushi

    2014-07-01

    The Prime Focus Spectrograph (PFS) is a new optical/near-infrared multi-fiber spectrograph designed for the prime focus of the 8.2m Subaru telescope. The metrology camera system of PFS serves as the optical encoder of the COBRA fiber motors for the configuring of fibers. The 380mm diameter aperture metrology camera will locate at the Cassegrain focus of Subaru telescope to cover the whole focal plane with one 50M pixel Canon CMOS sensor. The metrology camera is designed to provide the fiber position information within 5μm error over the 45cm focal plane. The positions of all fibers can be obtained within 1s after the exposure is finished. This enables the overall fiber configuration to be less than 2 minutes.

  17. Prime focus instrument of prime focus spectrograph for Subaru telescope

    NASA Astrophysics Data System (ADS)

    Wang, Shiang-Yu; Braun, David F.; Schwochert, Mark A.; Huang, Pin-Jie; Kimura, Masahiko; Chen, Hsin-Yo; Reiley, Daniel J.; Mao, Peter; Fisher, Charles D.; Tamura, Naoyuki; Chang, Yin-Chang; Hu, Yen-Sang; Ling, Hung-Hsu; Wen, Chih-Yi; Chou, Richard C.-Y.; Takato, Naruhisa; Sugai, Hajime; Ohyama, Youichi; Karoji, Hiroshi; Shimono, Atsushi; Ueda, Akitoshi

    2014-07-01

    The Prime Focus Spectrograph (PFS) is a new optical/near-infrared multi-fiber spectrograph design for the prime focus of the 8.2m Subaru telescope. PFS will cover 1.3 degree diameter field with 2394 fibers to complement the imaging capability of Hyper SuprimeCam (HSC). The prime focus unit of PFS called Prime Focus Instrument (PFI) provides the interface with the top structure of Subaru telescope and also accommodates the optical bench in which Cobra fiber positioners are located. In addition, the acquisition and guiding (AG) cameras, the optical fiber positioner system, the cable wrapper, the fiducial fibers, illuminator, and viewer, the field element, and the telemetry system are located inside the PFI. The mechanical structure of the PFI was designed with special care such that its deflections sufficiently match those of the HSC's Wide Field Corrector (WFC) so the fibers will stay on targets over the course of the observations within the required accuracy.

  18. Design inputs for a high-performance high-resolution near-infrared spectrograph

    NASA Astrophysics Data System (ADS)

    Hinkle, Kenneth H.; Joyce, Richard R.; Najita, Joan R.

    2010-07-01

    The combination of immersion grating and infrared array detector technologies allows the construction of highresolution spectrographs in the near-infrared that have capabilities similar to those of optical spectrographs. It is possible, for instance, to design multi-object spectrographs with very large wavelength coverage and high throughput. We explored the science and functional drivers for these spectrograph designs. Several key inputs into the design are reviewed including risk, mechanical-optical trades, and operations. We discuss a design for a fixed configuration spectrograph with either 1.1 - 2.5 or 3 - 5 μm simultaneous wavelength coverage.

  19. The Goddard High Resolution Spectrograph: Instrument, goals, and science results

    NASA Astrophysics Data System (ADS)

    Brandt, J. C.; Heap, S. R.; Beaver, E. A.; Boggess, A.; Carpenter, K. G.; Ebbets, D. C.; Hutchings, J. B.; Jura, M.; Leckrone, D. S.; Linsky, J. L.; Maran, S. P.; Savage, B. D.; Smith, A. M.; Trafton, L. M.; Walter, F. M.; Weymann, R. J.; Ake, T. B.; Bruhweiler, F.; Cardelli, J. A.; Lindler, D. J.; Malumuth, E.; Randall, C. E.; Robinson, R.; Shore, S. N.; Wahlgren, G.

    1994-08-01

    The Goddard High Resolution Spectrograph (GHRS), currently in Earth orbit on the Hubble Space Telescope (HST), operates in the wavelength range 1150-3200 A with spectral resolutions (lambda/delta lambda) of approximately 2 x 103, 2 x 104, and 1 x 103. The instrument and its development from inception, its current status, the approach to operations, representative results in the major areas of the scientific goals, and prospects for the future are described.

  20. Commissioning of the PMAS 3D-spectrograph

    NASA Astrophysics Data System (ADS)

    Kelz, Andreas; Roth, Martin M.; Becker, Thomas

    2003-03-01

    PMAS, the Potsdam Multi-Aperture Spectrophotometer, was successfully commissioned at the Calar Alto 3.5m telescope during 2001. PMAS is a medium-resolution, lensarray/fiber based integral field spectrograph, covering the whole optical wavelength range from 350 to 900 nm with optimized high efficiency in the blue. We review the commissioning activities and present the current status of this new instrument.

  1. The Goddard High Resolution Spectrograph: Instrument, goals, and science results

    NASA Technical Reports Server (NTRS)

    Brandt, J. C.; Heap, S. R.; Beaver, E. A.; Boggess, A.; Carpenter, K. G.; Ebbets, D. C.; Hutchings, J. B.; Jura, M.; Leckrone, D. S.; Linsky, J. L.

    1994-01-01

    The Goddard High Resolution Spectrograph (GHRS), currently in Earth orbit on the Hubble Space Telescope (HST), operates in the wavelength range 1150-3200 A with spectral resolutions (lambda/delta lambda) of approximately 2 x 10(exp 3), 2 x 10(exp 4), and 1 x 10(exp 3). The instrument and its development from inception, its current status, the approach to operations, representative results in the major areas of the scientific goals, and prospects for the future are described.

  2. The development of WIFIS: a wide integral field infrared spectrograph

    NASA Astrophysics Data System (ADS)

    Sivanandam, Suresh; Chou, Richard C. Y.; Moon, Dae-Sik; Ma, Ke; Millar-Blanchaer, Maxwell; Eikenberry, Stephen S.; Chun, Moo-Young; Kim, Sang Chul; Raines, Steven N.; Eisner, Joshua

    2012-09-01

    We present the current results from the development of a wide integral field infrared spectrograph (WIFIS). WIFIS offers an unprecedented combination of etendue and spectral resolving power for seeing-limited, integral field observations in the 0.9 - 1.8 μm range and is most sensitive in the 0.9 - 1.35 μ,m range. Its optical design consists of front-end re-imaging optics, an all-reflective image slicer-type, integral field unit (IFU) called FISICA, and a long-slit grating spectrograph back-end that is coupled with a HAWAII 2RG focal plane array. The full wavelength range is achieved by selecting between two different gratings. By virtue of its re-imaging optics, the spectrograph is quite versatile and can be used at multiple telescopes. The size of its field-of-view is unrivalled by other similar spectrographs, offering a 4.511x 1211 integral field at a 10-meter class telescope (or 2011 x 5011 at a 2.3-meter telescope). The use of WIFIS will be crucial in astronomical problems which require wide-field, two-dimensional spectroscopy such as the study of merging galaxies at moderate redshift and nearby star/planet-forming regions and supernova remnants. We discuss the final optical design of WIFIS, and its predicted on-sky performance on two reference telescope platforms: the 2.3-m Steward Bok telescope and the 10.4-m Gran Telescopio Canarias. We also present the results from our laboratory characterization of FISICA. IFU properties such as magnification, field-mapping, and slit width along the entire slit length were measured by our tests. The construction and testing of WIFIS is expected to be completed by early 2013. We plan to commission the instrument at the 2.3-m Steward Bok telescope at Kitt Peak, USA in Spring 2013.

  3. First light results from the Hermes spectrograph at the AAT

    NASA Astrophysics Data System (ADS)

    Sheinis, Andrew; Barden, Sam; Birchall, Michael; Carollo, Daniela; Bland-Hawthorn, Joss; Brzeski, Jurek; Case, Scott; Cannon, Russell; Churilov, Vladimir; Couch, Warrick; Dean, Robert; De Silva, Gayandhi; D'Orazi, Valentina; Farrell, Tony; Fiegert, Kristin; Freeman, Kenneth; Frost, Gabriella; Gers, Luke; Goodwin, Michael; Gray, Doug; Heald, Ron; Heijmans, Jeroen; Jones, Damien; Keller, Stephan; Klauser, Urs; Kondrat, Yuriy; Lawrence, Jon; Lee, Steve; Mali, Slavko; Martell, Sarah; Mathews, Darren; Mayfield, Don; Miziarski, Stan; Muller, Rolf; Pai, Naveen; Patterson, Robert; Penny, Ed; Orr, David; Shortridge, Keith; Simpson, Jeffrey; Smedley, Scott; Smith, Greg; Stafford, Darren; Staszak, Nicholas; Vuong, Minh; Waller, Lewis; Wylie de Boer, Elizabeth; Xavier, Pascal; Zheng, Jessica; Zhelem, Ross; Zucker, Daniel

    2014-07-01

    The High Efficiency and Resolution Multi Element Spectrograph, HERMES is an facility-class optical spectrograph for the AAT. It is designed primarily for Galactic Archeology [21], the first major attempt to create a detailed understanding of galaxy formation and evolution by studying the history of our own galaxy, the Milky Way. The goal of the GALAH survey is to reconstruct the mass assembly history of the of the Milky Way, through a detailed spatially tagged abundance study of one million stars. The spectrograph is based at the Anglo Australian Telescope (AAT) and is fed by the existing 2dF robotic fiber positioning system. The spectrograph uses VPH-gratings to achieve a spectral resolving power of 28,000 in standard mode and also provides a high-resolution mode ranging between 40,000 to 50,000 using a slit mask. The GALAH survey requires a SNR greater than 100 for a star brightness of V=14. The total spectral coverage of the four channels is about 100nm between 370 and 1000nm for up to 392 simultaneous targets within the 2 degree field of view. Hermes has been commissioned over 3 runs, during bright time in October, November and December 2013, in parallel with the beginning of the GALAH Pilot survey starting in November 2013. In this paper we present the first-light results from the commissioning run and the beginning of the GALAH Survey, including performance results such as throughput and resolution, as well as instrument reliability. We compare the abundance calculations from the pilot survey to those in the literature.

  4. The Software System for the AAO's HERMES Spectrograph

    NASA Astrophysics Data System (ADS)

    Shortridge, K.; Farrell, T.; Vuong, M.; Birchall, M.; Heald, R.

    2013-10-01

    The AAO's HERMES spectrograph will start operation in 2013. Its primary project will be a Galactic Archaeology survey that aims to reconstruct the early history of our Galaxy through precise measurements of the chemical abundances of one million stars. This paper describes some of the software aspects of the HERMES project: how it has evolved from the earlier AAO 2dF system, the extensive use of simulation for testing, the overall observing system, and the data reduction pipeline.

  5. The Hercules Échelle Spectrograph at Mt. John

    NASA Astrophysics Data System (ADS)

    Hearnshaw, J. B.; Barnes, S. I.; Kershaw, G. M.; Frost, N.; Graham, G.; Ritchie, R.; Nankivell, G. R.

    2002-03-01

    The High Efficiency and Resolution Canterbury University Large Échelle Spectrograph (HERCULES) a fibre-fed échelle spectrograph that was designed and built at the University of Canterbury and has been in operation at Mt. John University Observatory since April 2001.HERCULES receives light from the f/13.5 Cassegrain focus of the 1 m McLellan telescope. Resolving powers of R = 41 000, 70 000 and 82 000 are available. An R2 200 × 400 mm échelle grating provides dispersion and cross-dispersion uses a large BK7 prism in double pass. The wavelength coverage is designed to be 380-880 nm in a single exposure. The maximum detective quantum efficiency of the fibre, spectrograph and detector system is about 18% in 2 arc second seeing. High wavelength stability (to better than 10 ms-1 in radial velocity) is achieved by installing the whole instrument in a large vacuum tank at 2-4 torr and by there being no moving parts. The tank is in a thermally isolated and insulated environment. The paper describes the design philosophy of HERCULES and its performance during the first year of operation.

  6. Fibre Multi-Object Spectrograph (FMOS) for the Subaru Telescope

    NASA Astrophysics Data System (ADS)

    Kimura, Masahiko; Maihara, Toshinori; Iwamuro, Fumihide; Akiyama, Masayuki; Tamura, Naoyuki; Dalton, Gavin B.; Takato, Naruhisa; Tait, Philip; Ohta, Kouji; Eto, Shigeru; Mochida, Daisaku; Elms, Brian; Kawate, Kaori; Kurakami, Tomio; Moritani, Yuuki; Noumaru, Junichi; Ohshima, Norio; Sumiyoshi, Masanao; Yabe, Kiyoto; Brzeski, Jurek; Farrell, Tony; Frost, Gabriella; Gillingham, Peter R.; Haynes, Roger; Moore, Anna M.; Muller, Rolf; Smedley, Scott; Smith, Greg; Bonfield, David G.; Brooks, Charles B.; Holmes, Alan R.; Curtis Lake, Emma; Lee, Hanshin; Lewis, Ian J.; Froud, Tim R.; Tosh, Ian A.; Woodhouse, Guy F.; Blackburn, Colin; Content, Robert; Dipper, Nigel; Murray, Graham; Sharples, Ray; Robertson, David J.

    2010-10-01

    Fibre Multi-Object Spectrograph (FMOS) is the first near-infrared instrument with a wide field of view capable of acquiring spectra simultaneously from up to 400 objects. It has been developed as a common-use instrument for the F/2 prime-focus of the Subaru Telescope. The field coverage of 30' diameter is achieved using a new 3-element corrector optimized in the near-infrared (0.9-1.8μm) wavelength range. Due to limited space at the prime-focus, we have had to develop a novel fibre positioner, called ``Echidna'', together with two OH-airglow suppressed spectrographs. FMOS consists of three subsystems: the prime focus unit for IR, the fibre positioning system/connector units, and the two spectrographs. After full systems integration, FMOS was installed on the telescope in late 2007. Many aspects of the performance were checked through various test and engineering observations. In this paper, we present the optical and mechanical components of FMOS, and show the results of our on-sky engineering observations to date.

  7. SPRAT: Spectrograph for the Rapid Acquisition of Transients

    NASA Astrophysics Data System (ADS)

    Piascik, A. S.; Steele, Iain A.; Bates, Stuart D.; Mottram, Christopher J.; Smith, R. J.; Barnsley, R. M.; Bolton, B.

    2014-07-01

    We describe the development of a low cost, low resolution (R ~ 350), high throughput, long slit spectrograph covering visible (4000-8000) wavelengths. The spectrograph has been developed for fully robotic operation with the Liverpool Telescope (La Palma). The primary aim is to provide rapid spectral classification of faint (V ˜ 20) transient objects detected by projects such as Gaia, iPTF (intermediate Palomar Transient Factory), LOFAR, and a variety of high energy satellites. The design employs a volume phase holographic (VPH) transmission grating as the dispersive element combined with a prism pair (grism) in a linear optical path. One of two peak spectral sensitivities are selectable by rotating the grism. The VPH and prism combination and entrance slit are deployable, and when removed from the beam allow the collimator/camera pair to re-image the target field onto the detector. This mode of operation provides automatic acquisition of the target onto the slit prior to spectrographic observation through World Coordinate System fitting. The selection and characterisation of optical components to maximise photon throughput is described together with performance predictions.

  8. Effective Area of the Cosmic Origins Spectrograph below 1150 Å

    NASA Astrophysics Data System (ADS)

    McCandliss, Stephan R.; France, K.; Osterman, S.; Green, J. C.; McPhate, J. B.; Wilkinson, E.; COS

    2010-01-01

    The G140L segment B channel (R 2,000) of the Cosmic Origins Spectrograph (COS) recently installed on the Hubble Space Telescope (HST) has an effective area consistent with 10 cm2 in the bandpass between the Lyman edge at 912 Å and Lyβ. It has a slight plateau of 20 cm2 near 1050 Å and rises to a peak in excess of 1100 cm2 longward of 1140 Å. Up until now the general astronomical community has had only limited access to a low resolving power R 2,000 far-UV spectrograph, extending down to the Lyman limit, in the form of the shuttle carried instruments; the Hopkins Ultraviolet Telescope and the Berkeley Extreme and Far-UV Spectrograph. The low resolving power provides a unique capability to reach extremely faint flux limits and will enable new science investigations, such as those seeking to quantify the escape fraction of Lyman continuum photons from galaxies at low redshift, study the He II Gunn-Peterson effect in the redshift range 2 < z < 2.8, measure CO/H2 in dense interstellar environments, or make observations of the O VI λλ 1032, 1038 doublet. Observations of point sources will have the highest spectral resolution, since the small 2."5 diameter entrance aperture of COS is not optimized for extended source observations.

  9. Wide band focusing x-ray spectrograph with spatial resolution

    SciTech Connect

    Pikuz, S. A.; Douglass, J. D.; Shelkovenko, T. A.; Sinars, D. B.; Hammer, D. A.

    2008-01-15

    A new, wide spectral bandwidth x-ray spectrograph, the wide-bandwidth focusing spectrograph with spatial resolution (WB-FSSR), based on spherically bent mica crystals, is described. The wide bandwidth is achieved by combining three crystals to form a large aperture dispersive element. Since the WB-FSSR covers a wide spectral band, it is very convenient for application as a routine diagnostic tool in experiments in which the desired spectral coverage is different from one test to the next. The WB-FSSR has been tested in imploding wire-array experiments on a 1 MA pulsed power machine, and x-ray spectra were recorded in the 1-20 A spectral band using different orders of mica crystal reflection. Using a two mirror-symmetrically placed WB-FSSR configuration, it was also possible to distinguish between a real spectral shift and a shift of recorded spectral lines caused by the spatial distribution of the radiating plasma. A spectral resolution of about 2000 was demonstrated and a spatial resolution of {approx}100 {mu}m was achieved in the spectral band of 5-10 A in second order of mica reflection. A simple method of numerical analysis of spectrograph capability is proposed.

  10. High-resolution UV echelle spectrograph for environmental sensing

    NASA Astrophysics Data System (ADS)

    Clauson, Susan L.; Christesen, Steven D.; Spencer, Kevin M.

    2004-03-01

    Resonance Raman spectroscopy is an enhanced Raman technique that can be used to selectively identify a particular analyte in complex matrices. Resonance Raman requires the excitation laser to overlap with an absorption band of the analyte of interest. Since analytes have diverse absorption spectra, dilute concentrations may be detected when resonantly enhanced. A significant portion of interesting molecules absorb only in the UV; unfortunately current UV Raman instrumentation for scientifically desirable spectral resolution is large and costly. In the area of Homeland Defense, explosives, nerve agents, amino acid residues (for toxin analysis) and nucleic acids (for DNA detection and identification of bacteria) are all enhanced using UV laser sources. EIC Laboratories has developed a more user-friendly UVRRS spectrograph that is based upon the use of an echelle grating. The spectrograph has a footprint of 7" x 11" and is capable of providing 4 cm-1 resolution over a fairly wide spectral range. The spectrograph design and spectra from analytes of particular relevance will be presented.

  11. Hectochelle: A Multiobject Optical Echelle Spectrograph for the MMT

    NASA Astrophysics Data System (ADS)

    Szentgyorgyi, Andrew; Furesz, Gabor; Cheimets, Peter; Conroy, Maureen; Eng, Roger; Fabricant, Daniel; Fata, Robert; Gauron, Thomas; Geary, John; McLeod, Brian; Zajac, Joseph; Amato, Stephen; Bergner, Henry; Caldwell, Nelson; Dupree, Andrea; Goddard, Richard; Johnston, Everett; Meibom, Soeren; Mink, Douglas; Pieri, Mario; Roll, John; Tokarz, Susan; Wyatt, William; Epps, Harland; Hartmann, Lee; Meszaros, Szabolcz

    2011-10-01

    The Hectochelle is an optical band, fiber-fed, multiobject echelle spectrograph deployed at the MMT Observatory on Mount Hopkins, Arizona. The optical fibers that feed the Hectochelle are positioned by the Hectospec robot positioner on the MMT f/5 focal surface, and the Hectochelle shares an optical fiber feed system with the Hectospec, a moderate-dispersion spectrograph that is collocated with the Hectochelle. Hectochelle can record up to 240 spectra simultaneously at a resolution of 38,000. Spectra cover a single diffractive order that is approximately 150 Å wide. The total potential operating passband of the Hectochelle extends from 3800 Å to 9000 Å. Operated in conjunction with the MMT f/5 secondary, the MMT wide-field corrector, and the atmospheric dispersion compensator, the patrol field is 1° in diameter and the individual fiber slits are 1.5'' in diameter. The throughput of the combined telescope, fiber feed, and spectrograph is measured to be 6.1% at 5275 Å, exclusive of atmospheric extinction. A 20 minute observation of a V = 15 F-type star yields a signal-to-noise ratio of 35 per resolution element. Hectochelle had first light 2003 December 4 and continues to be operated at the MMT today.

  12. A near-infrared spectrograph for the Discovery Channel Telescope

    NASA Astrophysics Data System (ADS)

    Roe, H. G.; Dunham, E. W.; Bida, T. A.; Hall, J. C.; Degroff, W.

    2011-10-01

    Lowell Observatory is constructing the Discovery Channel Telescope (DCT) at Happy Jack, Arizona, approximately an hour from Lowell's main campus in Flagstaff, Arizona. The DCT is a 4.3-m optical/ infrared telescope. Construction of the telescope is complete and First Light of the DCT is planned for 2012Q2. In its initial configuration instruments will be co-mounted on a rotatable/selectable cube at the Cassegrain focus. Motorized deployable fold mirrors enable rapid switching amongst instruments. In the future the Nasmyth foci will be available for larger instruments as well. The first generation of instruments on DCT include: the Large Monolithic Imager (LMI), the Near-Infrared High-Throughput Spectrograph (NIHTS, pronounced "nights"), and the DeVeny optical spectrograph. The LMI contains a single large 6.1x6.1 K detector with a 12.5 arcmin2 FOV. NIHTS is a low resolution efficient near-infrared spectrograph and is the subject of this presentation. The DeVeny is Lowell's existing optical spectrograph with resolutions available between 500 and 4000. NIHTS is a low-resolution high-throughput infrared spectrograph covering 0.9-2.4 μm in a single fixed spectral setting at a resolution of »100. For simplicity and replicability NIHTS contains no moving parts. The science detector is a 10242 HAWAII-1 array. The fixed slit plate features an 80" long slit with several different slit widths (2,3,4 and 12 pixels) available along its length. The widest slit width is designed to allow accurate flux calibration, while the 3 and 4-pixel slits are closely matched to typical seeing at the DCT site (0.86" mean). Different resolutions will be rapidly selectable by dithering the telescope, and a typical observation is anticipated to involve a sequence of dithers both at the desired resolution and at SED resolution for calibration purposes. Offset guiding and wavefront sensing to control the active optics of the primary mirror are provided by the facility via deployable probes in

  13. The near infrared camera for the Subaru Prime Focus Spectrograph

    NASA Astrophysics Data System (ADS)

    Smee, Stephen A.; Gunn, James E.; Golebiowski, Mirek; Barkhouser, Robert; Vivès, Sebastien; Pascal, Sandrine; Carr, Michael; Hope, Stephen C.; Loomis, Craig; Hart, Murdock; Sugai, Hajime; Tamura, Naoyuki; Shimono, Atsushi

    2014-08-01

    We present the detailed design of the near infrared camera for the SuMIRe (Subaru Measurement of Images and Redshifts) Prime Focus Spectrograph (PFS) being developed for the Subaru Telescope. The PFS spectrograph is designed to collect spectra from 2394 objects simultaneously, covering wavelengths that extend from 380 nm - 1.26 μm. The spectrograph is comprised of four identical spectrograph modules, with each module collecting roughly 600 spectra from a robotic fiber positioner at the telescope prime focus. Each spectrograph module will have two visible channels covering wavelength ranges 380 nm - 640 nm and 640 nm - 955 nm, and one near infrared (NIR) channel with a wavelength range 955 nm - 1.26 μm. Dispersed light in each channel is imaged by a 300 mm focal length, f/1.07, vacuum Schmidt camera onto a 4k x 4k, 15 µm pixel, detector format. For the NIR channel a HgCdTe substrate-removed Teledyne 1.7 μm cutoff device is used. In the visible channels, CCDs from Hamamatsu are used. These cameras are large, having a clear aperture of 300 mm at the entrance window, and a mass of ~ 250 kg. Like the two visible channel cameras, the NIR camera contains just four optical elements: a two-element refractive corrector, a Mangin mirror, and a field flattening lens. This simple design produces very good imaging performance considering the wide field and wavelength range, and it does so in large part due to the use of a Mangin mirror (a lens with a reflecting rear surface) for the Schmidt primary. In the case of the NIR camera, the rear reflecting surface is a dichroic, which reflects in-band wavelengths and transmits wavelengths beyond 1.26 μm. This, combined with a thermal rejection filter coating on the rear surface of the second corrector element, greatly reduces the out-of-band thermal radiation that reaches the detector. The camera optics and detector are packaged in a cryostat and cooled by two Stirling cycle cryocoolers. The first corrector element serves as the

  14. Mouse Embryo Compaction.

    PubMed

    White, M D; Bissiere, S; Alvarez, Y D; Plachta, N

    2016-01-01

    Compaction is a critical first morphological event in the preimplantation development of the mammalian embryo. Characterized by the transformation of the embryo from a loose cluster of spherical cells into a tightly packed mass, compaction is a key step in the establishment of the first tissue-like structures of the embryo. Although early investigation of the mechanisms driving compaction implicated changes in cell-cell adhesion, recent work has identified essential roles for cortical tension and a compaction-specific class of filopodia. During the transition from 8 to 16 cells, as the embryo is compacting, it must also make fundamental decisions regarding cell position, polarity, and fate. Understanding how these and other processes are integrated with compaction requires further investigation. Emerging imaging-based techniques that enable quantitative analysis from the level of cell-cell interactions down to the level of individual regulatory molecules will provide a greater understanding of how compaction shapes the early mammalian embryo. PMID:27475854

  15. Reversible DNA compaction.

    PubMed

    González-Pérez, Alfredo

    2014-01-01

    In this review we summarize and discuss the different methods we can use to achieve reversible DNA compaction in vitro. Reversible DNA compaction is a natural process that occurs in living cells and viruses. As a result these process long sequences of DNA can be concentrated in a small volume (compacted) to be decompacted only when the information carried by the DNA is needed. In the current work we review the main artificial compacting agents looking at their suitability for decompaction. The different approaches used for decompaction are strongly influenced by the nature of the compacting agent that determines the mechanism of compaction. We focus our discussion on two main artificial compacting agents: multivalent cations and cationic surfactants that are the best known compacting agents. The reversibility of the process can be achieved by adding chemicals like divalent cations, alcohols, anionic surfactants, cyclodextrins or by changing the chemical nature of the compacting agents via pH modifications, light induced conformation changes or by redox-reactions. We stress the relevance of electrostatic interactions and self-assembly as a main approach in order to tune up the DNA conformation in order to create an on-off switch allowing a transition between coil and compact states. The recent advances to control DNA conformation in vitro, by means of molecular self-assembly, result in a better understanding of the fundamental aspects involved in the DNA behavior in vivo and serve of invaluable inspiration for the development of potential biomedical applications. PMID:24444152

  16. Attaining m s-1 level intrinsic Doppler precision with RHEA, a low-cost single-mode spectrograph

    NASA Astrophysics Data System (ADS)

    Feger, Tobias; Ireland, Michael J.; Schwab, Christian; Bento, Joao; Bacigalupo, Carlos; Coutts, David W.

    2016-08-01

    We present RHEA, a compact and inexpensive single-mode spectrograph which is built to exploit the capabilities of modest-sized telescopes in an economic way. The instrument is fed by up to seven optical waveguides with the aim of achieving an efficient and modal-noise-free unit, suitable for attaining extreme Doppler precision. The cross-dispersed layout features a wavelength coverage from 430-650 nm, with spectral resolution of R ˜75,000. When coupled to small telescopes using fast tip/tilt control, our instrument is well-suited to sensitive spectroscopy. Example science cases are accurate radial velocity studies of low to intermediate-mass giant stars with the purpose of searching for giant plants and using asteroseismology to simultaneously measure the host star parameters. In this paper we describe the final instrument design and present first results from testing the internal stability.

  17. GRASSP (GRAnada Sprite Spectrograph and Polarimeter). Design and implementation.

    NASA Astrophysics Data System (ADS)

    Passas, María; Sánchez, Justo; Gordillo-Vázquez, Francisco J.; Luque, Alejandro; Parra-Rojas, Francisco C.

    2013-04-01

    Transient luminous events (TLEs) are short optical emissions that occur in the upper atmosphere above storm systems. They appear between 15 and 90 km altitude and last between less than a millisecond to up to two seconds. So far there are no polarization studies of TLEs, nor high-resolution spectroscopy results which could help us to understand the kinetics and electrodynamics of these kind of optical emissions. The GRASSP (Granada Sprite Spectrograph and Polarimeter) instrument has been developed to measure simultaneously the polarization and the spectra of the light emitted from these TLEs with medium spectral resolution (0.45nm). By consulting a real-time lightning database, the telescope aims automatically to the region of the sky where a TLE is predicted to appear. The instrument is located outside the 2.2 m dome of the German-Spanish Astronomical Center at Calar Alto, Sierra de Los Filabres, north of Almería (Andalucía, Southern Spain), at 2168 meters above mean sea level. From this location we can observe the western Mediterranean Sea zone (37°-45°N; 2°W-6°E) with an elevation of 10°-35° above the horizon, a region where the most TLE activity in Europe takes place. GRASSP is a prototype which consists of a spectrograph and a polarimeter, both installed on a telescope mount. The 6-channel imaging polarimeter will cover a spectral range from 500 - 750 nm, with a polarized / unpolarized sensitivity smaller than 5 %. It will present a circular field of view of 5° and a CCD of 2000 × 2000 pixels with a FOV of 15 µm/px. The goal is to find the 4 Stokes parameters in a single shot. To do so, the polarimeter consists of seven circular windows disposed over a telescope surface, six of them are located around the border of the circle and the last one is located in the center. This single window will show the unfiltered image and the six remaining ones include a different polarizer ( 0° 45° 90° 180° linear polarizers and left and right circular

  18. CAFE: Calar Alto Fiber-fed Échelle spectrograph

    NASA Astrophysics Data System (ADS)

    Aceituno, J.; Sánchez, S. F.; Grupp, F.; Lillo, J.; Hernán-Obispo, M.; Benitez, D.; Montoya, L. M.; Thiele, U.; Pedraz, S.; Barrado, D.; Dreizler, S.; Bean, J.

    2013-04-01

    We present here CAFE, the Calar Alto Fiber-fed Échelle spectrograph, a new instrument built at the Centro Astronomico Hispano Alemán (CAHA). CAFE is a single-fiber, high-resolution (R ~ 70 000) spectrograph, covering the wavelength range between 3650-9800 Å. It was built on the basis of the common design for Échelle spectrographs. Its main aim is to measure radial velocities of stellar objects up to V ~ 13-14 mag with a precision as good as a few tens of m s-1. To achieve this goal the design was simplified at maximum, removing all possible movable components, the central wavelength is fixed, as is the wavelength coverage; there is no filter wheel, etc. Particular care was taken with the thermal and mechanical stability. The instrument is fully operational and publically accessible at the 2.2 m telescope of the Calar Alto Observatory. In this article we describe (i) the design, summarizing its manufacturing phase; (ii) characterize the main properties of the instrument; (iii) describe the reduction pipeline; and (iv) show the results from the first light and commissioning runs. The preliminar results indicate that the instrument fulfills the specifications and can achieve the planned goals. In particular, the results show that the instrument is more efficient than anticipated, reaching a signal-to-noise of ~20 for a stellar object as faint as V ~ 14.5 mag in ~2700 s integration time. The instrument is a wonderful machine for exoplanetary research (by studying large samples of possible systems cotaining massive planets), galactic dynamics (highly precise radial velocities in moving groups or stellar associations), or astrochemistry.

  19. The SAURON project - I. The panoramic integral-field spectrograph

    NASA Astrophysics Data System (ADS)

    Bacon, R.; Copin, Y.; Monnet, G.; Miller, Bryan W.; Allington-Smith, J. R.; Bureau, M.; Carollo, C. M.; Davies, Roger L.; Emsellem, Eric; Kuntschner, Harald; Peletier, Reynier F.; Verolme, E. K.; de Zeeuw, P. Tim

    2001-09-01

    A new integral-field spectrograph, SAURON, is described. It is based on the TIGER principle, and uses a lenslet array. SAURON has a large field of view and high throughput, and allows simultaneous sky subtraction. Its design is optimized for studies of the stellar kinematics, gas kinematics, and line-strength distributions of nearby early-type galaxies. The instrument design and specifications are described, as well as the extensive analysis software which was developed to obtain fully calibrated spectra, and the associated kinematic and line-strength measurements. A companion paper will report on the first results obtained with SAURON on the William Herschel Telescope.

  20. Design of the KOSMOS oil-coupled spectrograph camera lenses

    NASA Astrophysics Data System (ADS)

    O'Brien, Thomas P.; Derwent, Mark; Martini, Paul; Poczulp, Gary

    2014-07-01

    We present the design details of oil-coupled lens groups used in the KOSMOS spectrograph camera. The oil-coupled groups use silicone rubber O-rings in a unique way to accurately center lens elements with high radial and axial stiffness while also allowing easy assembly. The O-rings robustly seal the oil within the lens gaps to prevent oil migration. The design of an expansion diaphragm to compensate for differential expansion due to temperature changes is described. The issues of lens assembly, lens gap shimming, oil filling and draining, bubble mitigation, material compatibility, mechanical inspection, and optical testing are discussed.

  1. Spectrographic studies: Electron induced luminescence in optical materials

    NASA Technical Reports Server (NTRS)

    Romanko, J.; Miles, J. K.; Cheever, P. R.

    1971-01-01

    The spectral luminescence induced in UV grade sapphire, MgF2 and LiF2, three fused silicas, and three Corning glasses, by 1/2, 1, 2, and 3 MeV electrons was recorded. In the wavelength range from the LiF UV cutoff to the near visible, a plane-grating spectrograph with photographic recording at resolutions of 0.8 and 1.6 nm was utilized. Qualitative results based on relative density tracings of seven of the nine materials obtained from preliminary plates are given.

  2. Manufacturing and integration of the IFS integral spectrograph

    NASA Astrophysics Data System (ADS)

    De Caprio, V.; Giro, E.; Claudi, R.; Anselmi, U.; Bruno, P.; Cascone, E.; Desidera, S.; Fantinel, D.; Gratton, R.; Incorvaia, S.; Lessio, L.; Kasper, M.; Lizon, J. L.; Mesa, D.; Sant'Ambrogio, E.; Scuderi, S.; Stadler, E.; Turatto, M.; Dohlen, K.; Beuzit, J. L.; Antichi, J.; Hubin, N.; Wildi, F.; Puget, P.

    2010-07-01

    Currently in the phase of the assembly, the Integral Field Spectrograph (IFS) is part of Sphere, which will see the first light at ESO Paranal as a VLT second generation instruments in the 2011. In this paper we will describe the main aspects in the Assembly, Integration and Testing phase (AIT) of the instrument at INAF-Osservatorio Astronomico di Padova (OAPD) laboratory at the current stage. As result of the AIT, a full set of tests and qualifications of IFS subcomponents will be discussed. These tests have been designed and realized with the purpose to obtain an accurate comparison between design goals and effective performances of the instrument.

  3. CCD readout electronics for the Subaru Prime Focus Spectrograph

    NASA Astrophysics Data System (ADS)

    Hope, Stephen C.; Gunn, James E.; Loomis, Craig P.; Fitzgerald, Roger E.; Peacock, Grant O.

    2014-07-01

    The following paper details the design for the CCD readout electronics for the Subaru Telescope Prime Focus Spectrograph (PFS). PFS is designed to gather spectra from 2394 objects simultaneously, covering wavelengths that extend from 380 nm to 1260 nm. The spectrograph is comprised of four identical spectrograph modules, each collecting roughly 600 spectra. The spectrograph modules provide simultaneous wavelength coverage over the entire band through the use of three separate optical channels: blue, red, and near infrared (NIR). A camera in each channel images the multi-object spectra onto a 4k × 4k, 15 μm pixel, detector format. The two visible cameras use a pair of Hamamatsu 2k × 4k CCDs with readout provided by custom electronics, while the NIR camera uses a single Teledyne HgCdTe 4k × 4k detector and Teledyne's ASIC Sidecar to read the device. The CCD readout system is a custom design comprised of three electrical subsystems - the Back End Electronics (BEE), the Front End Electronics (FEE), and a Pre-amplifier. The BEE is an off-the-shelf PC104 computer, with an auxiliary Xilinx FPGA module. The computer serves as the main interface to the Subaru messaging hub and controls other peripheral devices associated with the camera, while the FPGA is used to generate the necessary clocks and transfer image data from the CCDs. The FEE board sets clock biases, substrate bias, and CDS offsets. It also monitors bias voltages, offset voltages, power rail voltage, substrate voltage and CCD temperature. The board translates LVDS clock signals to biased clocks and returns digitized analog data via LVDS. Monitoring and control messages are sent from the BEE to the FEE using a standard serial interface. The Pre-amplifier board resides behind the detectors and acts as an interface to the two Hamamatsu CCDs. The Pre-amplifier passes clocks and biases to the CCDs, and analog CCD data is buffered and amplified prior to being returned to the FEE. In this paper we describe the

  4. Optical filters on board the Space Telescope Imaging Spectrograph (STIS)

    NASA Astrophysics Data System (ADS)

    Coffelt, Everett L.; Martella, Mark A.

    1996-11-01

    The space telescope imaging spectrograph (STIS) instrument is due to be installed on board the Hubble Space Telescope (HST) in 1997. STIS uses 20 filters located on a wheel that can rotate any one of 88 apertures or combination filter/aperture in to the beam path. The instrument incorporates a continuous range of spectral response from the VUV (115.0 nm) to 1 micrometer. Therefore, filters that perform in the VUV are discussed as well as filters that operate in the near infrared. Neutral density filters are also being used for on-board calibration from 300 nm to Lyman-Alpha (121.6 nm).

  5. HIRES: the high resolution spectrograph for the E-ELT

    NASA Astrophysics Data System (ADS)

    Zerbi, F. M.; Bouchy, F.; Fynbo, J.; Maiolino, R.; Piskunov, N.; Rebolo Lopez, R.; Santos, N.; Strassmeier, K.; Udry, S.; Vanzi, L.; Riva, M.; Basden, A.; Boisse, I.; Bonfils, X.; Buscher, D.; Cabral, A.; Dimarcantonio, P.; Di Varano, I.; Henry, D.; Monteiro, M.; Morris, T.; Murray, G.; Oliva, Ernesto; Parry, I.; Pepe, F.; Quirrenbach, A.; Rasilla, J. L.; Rees, P.; Stempels, E.; Valenziano, L.; Wells, M.; Wildi, F.; Origlia, L.; Allende Prieto, C.; Chiavassa, A.; Cristiani, S.; Figueira, P.; Gustafsson, B.; Hatzes, A.; Haehnelt, M.; Heng, K.; Israelian, G.; Kochukhov, O.; Lovis, C.; Marconi, A.; Martins, C. J. A. P.; Noterdaeme, P.; Petitjean, P.; Puzia, T.; Queloz, D.; Reiners, A.; Zoccali, M.

    2014-08-01

    The current instrumentation plan for the E-ELT foresees a High Resolution Spectrograph conventionally indicated as HIRES. Shaped on the study of extra-solar planet atmospheres, Pop-III stars and fundamental physical constants, HIRES is intended to embed observing modes at high-resolution (up to R=150000) and large spectral range (from the blue limit to the K band) useful for a large suite of science cases that can exclusively be tackled by the E-ELT. We present in this paper the solution for HIRES envisaged by the "HIRES initiative", the international collaboration established in 2013 to pursue a HIRES on E-ELT.

  6. Updated Status and Performance for the Cosmic Origins Spectrograph

    NASA Astrophysics Data System (ADS)

    Taylor, Joanna M.; De Rosa, Gisella; Debes, John H.; Ely, Justin; Fix, Mees B.; Fox, Andrew; Jedrzejewski, Robert I.; Lockwood, Sean A.; Monroe, TalaWanda R.; Oliveira, Cristina M.; Peeples, Molly S.; Penton, Steven V.; Plesha, Rachel; Proffitt, Charles R.; Roman-Duval, Julia; Sahnow, David J.; Sonnentrucker, Paule; Walborn, Nolan R.; White, James

    2016-06-01

    The Cosmic Origins Spectrograph (COS) was installed on the Hubble Space Telescope (HST) in May 2009. COS is designed to perform high-sensitivity medium- and low-resolution spectroscopy of astronomical objects in the far-ultraviolet (FUV) and near-ultraviolet (NUV) wavelength regimes. We present updates on the time-dependent sensitivities of both the NUV and FUV detectors. Additionally, we discuss the appearance and mitigation of transient, isolated regions of increased count rates on the COS FUV detector called “hot spots”. We also present updates to the COS calibration pipeline, CalCOS, that provide improvements to COS data products.

  7. Video Cameras in the Ondrejov Flare Spectrograph Results and Prospects

    NASA Astrophysics Data System (ADS)

    Kotrc, P.

    Since 1991 video cameras have been widely used both in the image and in the spectral data acquisition of the Ondrejov Multichannel Flare Spectrograph. In addition to classical photographic data registration, this kind of detectors brought new possibilities, especially into dynamical solar phenomena observations and put new requirements on the digitization, archiving and data processing techniques. The unique complex video system consisting of four video cameras and auxiliary equipment was mostly developed, implemented and used in the Ondrejov observatory. The main advantages and limitations of the system are briefly described from the points of view of its scientific philosophy, intents and outputs. Some obtained results, experience and future prospects are discussed.

  8. Two-Dimensional Spectroscopy with the Cosmic Origins Spectrograph

    NASA Astrophysics Data System (ADS)

    Penton, Steven V.; Sahnow, D.; France, K.

    2011-05-01

    The circular aperture of HSTs' Cosmic Origins Spectrograph (COS) is 2.5" in diameter, but transmission extends out to a 4" diameter. The NUV MAMA and the FUV microchannel plates image the sky over the full extent of the transmission. The cross-dispersion plate scale of the NUV channel is 0.02" and is 0.1" for the FUV channel. In this presentation we will discuss the capabilities and limitations of performing two-dimensional spectroscopy, in the cross-dispersion direction, with COS. In particular, we will discuss FUV detector effects, such as fixed pattern noise, gain sag, and Y walk, and the latest techniques for their correction.

  9. Compaction behavior of isomalt after roll compaction.

    PubMed

    Quodbach, Julian; Mosig, Johanna; Kleinebudde, Peter

    2012-01-01

    The suitability of the new isomalt grade galenIQ™ 801 for dry granulation and following tableting is evaluated in this study. Isomalt alone, as well as a blend of equal parts with dibasic calcium phosphate, is roll compacted and tableted. Particle size distribution and flowability of the granules and friability and disintegration time of the tablets are determined. Tensile strength of tablets is related to the specific compaction force during roll compaction and the tableting force. In all cases, the tensile strength increases with raising tableting forces. The specific compaction force has a different influence. For isomalt alone the tensile strength is highest for tablets made from granules prepared at 2 kN/cm and 6 kN/cm and decreases at higher values, i.e., >10 kN/cm. Tensile strength of the blend tablets is almost one third lower compared to the strongest tablets of pure isomalt. Friability of pure isomalt tablets is above the limit. Disintegration time is longest when the tensile strength is at its maximum and decreases with higher porosity and lower tensile strengths. Isomalt proves to be suitable for tableting after roll compaction. Even though the capacity as a binder might not be as high as of other excipients, it is a further alternative for the formulation scientist. PMID:24300366

  10. Compaction Behavior of Isomalt after Roll Compaction

    PubMed Central

    Quodbach, Julian; Mosig, Johanna; Kleinebudde, Peter

    2012-01-01

    The suitability of the new isomalt grade galenIQ™ 801 for dry granulation and following tableting is evaluated in this study. Isomalt alone, as well as a blend of equal parts with dibasic calcium phosphate, is roll compacted and tableted. Particle size distribution and flowability of the granules and friability and disintegration time of the tablets are determined. Tensile strength of tablets is related to the specific compaction force during roll compaction and the tableting force. In all cases, the tensile strength increases with raising tableting forces. The specific compaction force has a different influence. For isomalt alone the tensile strength is highest for tablets made from granules prepared at 2 kN/cm and 6 kN/cm and decreases at higher values, i.e., >10 kN/cm. Tensile strength of the blend tablets is almost one third lower compared to the strongest tablets of pure isomalt. Friability of pure isomalt tablets is above the limit. Disintegration time is longest when the tensile strength is at its maximum and decreases with higher porosity and lower tensile strengths. Isomalt proves to be suitable for tableting after roll compaction. Even though the capacity as a binder might not be as high as of other excipients, it is a further alternative for the formulation scientist. PMID:24300366

  11. Elliptical x-ray analyzer spectrograph application to a laser-produced plasma

    SciTech Connect

    Tanaka, T.J.; Palmer, M.A.; Henke, B.L.

    1985-01-01

    This spectrograph was designed to record a range of 100 to 2000 eV x-rays on calibrated Kodak Rar-2497 film. Using point calibrations and theoretical models, the spectrograph efficiency was predicted. Basic spectrograph geometry and photographic calibrations are presented in companion papers. A 20 J, 6 ns duration Nd:glass laser pulse was focussed upon planar targets of gold, aluminum, teflon and boron carbide. Sample spectra for line and x-ray yields analysis are presented.

  12. CUBES: cassegrain U-band Brazil-ESO spectrograph

    NASA Astrophysics Data System (ADS)

    Barbuy, B.; Bawden Macanhan, V.; Bristow, P.; Castilho, B.; Dekker, H.; Delabre, B.; Diaz, M.; Gneiding, C.; Kerber, F.; Kuntschner, H.; La Mura, G.; Maciel, W.; Meléndez, J.; Pasquini, L.; Pereira, C. B.; Petitjean, P.; Reiss, R.; Siqueira-Mello, C.; Smiljanic, R.; Vernet, J.

    2014-11-01

    CUBES is a high-efficiency, medium-resolution ( R˜20,000) ground based UV (300-400 nm) spectrograph, to be installed in the cassegrain focus of one of ESO's VLT unit telescopes in 2017/18. The CUBES project is a joint venture between ESO and IAG/USP, and LNA/MCTI. CUBES will provide access to a wealth of new and relevant information for stellar as well as extragalactic sources. Main science cases include the study of beryllium and heavy elements in metal-poor stars, the direct determination of carbon, nitrogen and oxygen abundances by study of molecular bands in the UV range, as well as the study of active galactic nuclei and the quasar absorption lines. With a streamlined modern instrument design, high efficiency dispersing elements and UV-sensitive detectors, it will give a significant gain in sensitivity over existing ground based medium-high resolution spectrographs, enabling vastly increased sample sizes accessible to the astronomical community. We present here a brief overview of the project including the status, science cases and a discussion of the design options.

  13. Astrophotonic micro-spectrographs in the era of ELTs

    NASA Astrophysics Data System (ADS)

    Blind, N.; Le Coarer, E.; Kern, P.; Bland-Hawthorn, J.

    2014-08-01

    The next generation of Extremely Large Telescopes (ELT), with diameters up to 39 meters, will start opera- tion in the next decade and promises new challenges in the development of instruments. The growing field of astrophotonics (the use of photonic technologies in astronomy) can partly solve this problem by allowing mass production of fully integrated and robust instruments combining various optical functions, with the potential to reduce the size, complexity and cost of instruments. In this paper, we focus on developments in integrated micro-spectrographs and their potential for ELTs. We take an inventory of the identified technologies currently in development, and compare the performance of the different concepts. We show that in the current context of single-mode instruments, integrated spectrographs making use of, e.g., a photonic lantern can be a solution to reach the desired performance. However, in the longer term, there is a clear need to develop multimode devices to improve overall the throughput and sensitivity, while decreasing the instrument complexity.

  14. EMIR: cryogenic NIR multi-object spectrograph for GTC

    NASA Astrophysics Data System (ADS)

    Balcells, Marc; Guzman, R.; Patron, J.; Aragon-Salamanca, Alfonso; Azcue, J.; Ballester Lluch, Jose A.; Barroso, M. T.; Beigbeder, F.; Brau-Nogue, S.; Cardiel, N.; Carter, Dave; Diaz-Garcia, Jose J.; de la Fuente, E.; Fuentes, F. Javier; Fragoso-Lopez, Ana B.; Gago, Fernando; Gallego, J.; Gomez-Elvira, J.; Heredero, J. C.; Jones, Damien J.; Lopez, J. C.; Luke, P.; Manescau, Antonio; Munoz, T.; Peletier, R. F.; Pello, R.; Picat, Jean P.; Robertson, David J.; Rodriguez, J. A.; Serrano, Angel; Sharples, Ray M.; Zamorano, J.

    2000-08-01

    EMIR is a near-IR, multi-slit camera-spectrograph under development for the 10m GTC on La Palma. It will deliver up to 45 independent R equals 3500-4000 spectra of sources over a field of view of 6 feet by 3 feet, and allow NIR imaging over a 6 foot by 6 foot FOV, with spatial sampling of 0.175 inch/pixel. The prime science goal of the instrument is to open K-band, wide field multi-object spectroscopy on 10m class telescopes. Science applications range from the study of star-forming galaxies beyond z equals 2, to observations of substellar objects and dust-enshrouded star formation regions. Main technological challenges include the large optics, the mechanical and thermal stability and the need to implement a mask exchange mechanism that does not require warming up the spectrograph. EMIR is begin developed by the Instituto de Astrofisica de Canarias, the Instituto Nacional de Tecnica Aeroespacial, the Universidad Complutense de Madrid, the Observatoire Midi-Pyrennees, and the University of Durham. Currently in its Preliminary Design phase, EMIR is expected to start science operation in 2004.

  15. Support of the balloon-borne ultraviolet stellar spectrograph

    NASA Technical Reports Server (NTRS)

    Timothy, J. G.

    1986-01-01

    A (256 x 1024)-pixel imaging ultraviolet Multi-mode Microchannel Array (MAMA) detector system for flight was fabricated, evaluated, and environmentally tested for flight on the Balloon Borne Ultraviolet Stellar Spectrograph (BUSS). The goal of the program was to replace the existing SEC Vidicon with the pulse-counting MAMA detector in order to, first, improve the overall sensitivity of the BUSS telescope and spectrograph for observations of stars down to m sub v = 7 and fainter, and, second, to improve the spectral resolution and wavelength accuracy by eliminating the image drifts in the Vidicon caused by magnetic field effects. A sealed MAMA detector tube structure employing a remotely processed photocathode mounted on a window in proximity focus with the front face of the MCP was developed to avoid contamination produced by a noisy and unstable device. The configuration of the BUSS detector system in its flight ready configuration is shown. The quantum efficiency curve for the semi-transparent Cs2Te photocathode is also shown.

  16. X-shooter near infra-red spectrograph cryogenic design

    NASA Astrophysics Data System (ADS)

    Roelfsema, Ronald; Albers, Peter; Lizon, Jean-Louis; van Dael, Pieter; Elswijk, Eddy; Groot, Paul; Hanenburg, Hiddo; Kragt, Jan; Navarro, Ramon; Tromp, Niels; Wulterkens, Gerben

    2008-07-01

    X-shooter is a high-efficiency spectrograph capable of simultaneously observing the complete spectral range of 300- 2500 nm. The instrument will be located at the Cassegrain focus of one of the VLT UTs. To allow sky back ground limited observations the 120 kg Optical Bench of the NIR Spectrograph and the HAWAII-2RG detector are cooled to 105 K and 82 K respectively. To ensure vibrationless operation the cooling is performed by a LN2 bath-cryostat. The thermal stability requirements for the Optical Box are very tight (order of 100 mK) considering that the NIR-cryostat is subject to telescope movement and LN2 level variations. Large glass optics are limiting the cooldown. To speed up the cooldown the cooling concept of the Optical Box includes the utilization of LN2 heat exchangers. To avoid asymptotic stabilizing times the Optical Box is cooled below the operating temperature. When the optics reach a temperature slightly above the operating temperature the temperature of the Optical Box is quickly brought back to stabilize the optics. Dedicated controllers, strapping and heaters are used for temperature stabilization during steady state. A cryostat hold time of 24 hours with the minimum amount of LN2 in view of the tight mass budget requires strict control of the power budget and careful control of the design margins. This is ensured by precise modeling of the temperature behavior. The thermal model is compared with the actual measured thermal behavior.

  17. Calibrating echelle spectrographs with Fabry-Pérot etalons

    NASA Astrophysics Data System (ADS)

    Bauer, F. F.; Zechmeister, M.; Reiners, A.

    2015-09-01

    Context. Over the past decades hollow-cathode lamps have been calibration standards for spectroscopic measurements. Advancing to cm/s radial velocity precisions with the next generation of instruments requires more suitable calibration sources with more lines and fewer dynamic range problems. Fabry-Pérot interferometers provide a regular and dense grid of lines and homogeneous amplitudes, which makes them good candidates for next-generation calibrators. Aims: We investigate the usefulness of Fabry-Pérot etalons in wavelength calibration, present an algorithm to incorporate the etalon spectrum in the wavelength solution, and examine potential problems. Methods: The quasi-periodic pattern of Fabry-Pérot lines was used along with a hollow-cathode lamp to anchor the numerous spectral features on an absolute scale. We tested our method with the HARPS spectrograph and compared our wavelength solution to the one derived from a laser frequency comb. Results: The combined hollow-cathode lamp/etalon calibration overcomes large distortion (50 m/s) in the wavelength solution of the HARPS data reduction software. The direct comparison to the laser frequency comb shows differences of only 10 m/s at most. Conclusions: Combining hollow-cathode lamps with Fabry-Pérot interferometers can lead to substantial improvements in the wavelength calibration of echelle spectrographs. Etalons can provide economical alternatives to the laser frequency comb, especially for smaller projects.

  18. The Rapid Acquisition Imaging Spectrograph Experiment (RAISE) Sounding Rocket Investigation

    NASA Astrophysics Data System (ADS)

    Laurent, Glenn T.; Hassler, Donald M.; Deforest, Craig; Slater, David D.; Thomas, Roger J.; Ayres, Thomas; Davis, Michael; de Pontieu, Bart; Diller, Jed; Graham, Roy; Michaelis, Harald; Schuele, Udo; Warren, Harry

    2016-03-01

    We present a summary of the solar observing Rapid Acquisition Imaging Spectrograph Experiment (RAISE) sounding rocket program including an overview of the design and calibration of the instrument, flight performance, and preliminary chromospheric results from the successful November 2014 launch of the RAISE instrument. The RAISE sounding rocket payload is the fastest scanning-slit solar ultraviolet imaging spectrograph flown to date. RAISE is designed to observe the dynamics and heating of the solar chromosphere and corona on time scales as short as 100-200ms, with arcsecond spatial resolution and a velocity sensitivity of 1-2km/s. Two full spectral passbands over the same one-dimensional spatial field are recorded simultaneously with no scanning of the detectors or grating. The two different spectral bands (first-order 1205-1251Å and 1524-1569Å) are imaged onto two intensified Active Pixel Sensor (APS) detectors whose focal planes are individually adjusted for optimized performance. RAISE reads out the full field of both detectors at 5-10Hz, recording up to 1800 complete spectra (per detector) in a single 6-min rocket flight. This opens up a new domain of high time resolution spectral imaging and spectroscopy. RAISE is designed to observe small-scale multithermal dynamics in Active Region (AR) and quiet Sun loops, identify the strength, spectrum and location of high frequency waves in the solar atmosphere, and determine the nature of energy release in the chromospheric network.

  19. Ultra-Compact, Superconducting Spectrometer-on-a-Chip at Submillimeter Wavelengths

    NASA Technical Reports Server (NTRS)

    Chattopadhyay, Goutam; Zmuidzinas, Jonas; Bradford, Charles M.; Leduc, Henry G.; Day, Peter K.; Swenson, Loren; Hailey-Dunsheath, Steven; O'Brient, Roger C.; Padin, Stephen; Shirokoff, Erik D.; McKenney, Christopher; Reck, Theodore; Siles, Jose V.; Barry, Peter; Doyle, Simon; Mauskopf, Philip; Llombart, Nuria; Kovacs, Attila; Marrone, Dan P.

    2013-01-01

    Small size, wide spectral bandwidth, and highly multiplexed detector readout are required to develop powerful multi-beam spectrometers for high-redshift observations. Currently available spectrometers at these frequencies are large and bulky. The grating sizes for these spectrometers are prohibitive. This fundamental size issue is a key limitation for space-based spectrometers for astrophysics applications. A novel, moderate-resolving-power (R-700), ultra-compact spectrograph-on-a-chip for millimeter and submillimeter wavelengths is the solution.

  20. Compact Raman instrumentation for process and environmental monitoring

    NASA Astrophysics Data System (ADS)

    Carrabba, Michael M.; Spencer, Kevin M.; Rauh, R. D.

    1991-04-01

    Raman spectroscopy is a powerful noninvasive tool for elucidating chemical structure. Like infrared spectroscopy, it has many potential practical applications, such as process monitoring, environmental sensing, clinical analysis, forensic identification, and as a detector for use with analytical instruments. Until recently, however, Raman has been considered mainly in the context of basic research. The present generation of high performance Raman instruments tend to be large, complex and expensive, and thus have been of primary interest only to specialists in the field. This paper will discuss the development of a compact Raman spectrometer system consisting of a diode laser, fiber optics of excitation and collection, and a compact spectrograph with charge coupled device (CCD) detection.

  1. ACOUSTIC COMPACTION LAYER DETECTION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The depth and strength of compacted layers in fields have been determined traditionally using the ASAE standardized cone penetrometer method. However, an on-the-go method would be much faster and much less labor intensive. The soil measurement system described here attempts to locate the compacted...

  2. Dynamical compactness and sensitivity

    NASA Astrophysics Data System (ADS)

    Huang, Wen; Khilko, Danylo; Kolyada, Sergiĭ; Zhang, Guohua

    2016-05-01

    To link the Auslander point dynamics property with topological transitivity, in this paper we introduce dynamically compact systems as a new concept of a chaotic dynamical system (X , T) given by a compact metric space X and a continuous surjective self-map T : X → X. Observe that each weakly mixing system is transitive compact, and we show that any transitive compact M-system is weakly mixing. Then we discuss the relationships between it and other several stronger forms of sensitivity. We prove that any transitive compact system is Li-Yorke sensitive and furthermore multi-sensitive if it is not proximal, and that any multi-sensitive system has positive topological sequence entropy. Moreover, we show that multi-sensitivity is equivalent to both thick sensitivity and thickly syndetic sensitivity for M-systems. We also give a quantitative analysis for multi-sensitivity of a dynamical system.

  3. Compaction properties of isomalt.

    PubMed

    Bolhuis, Gerad K; Engelhart, Jeffrey J P; Eissens, Anko C

    2009-08-01

    Although other polyols have been described extensively as filler-binders in direct compaction of tablets, the polyol isomalt is rather unknown as pharmaceutical excipient, in spite of its description in all the main pharmacopoeias. In this paper the compaction properties of different types of ispomalt were studied. The types used were the standard product sieved isomalt, milled isomalt and two types of agglomerated isomalt with a different ratio between 6-O-alpha-d-glucopyranosyl-d-sorbitol (GPS) and 1-O-alpha-d-glucopyranosyl-d-mannitol dihydrate (GPM). Powder flow properties, specific surface area and densities of the different types were investigated. Compactibility was investigated by compression of the tablets on a compaction simulator, simulating the compression on high-speed tabletting machines. Lubricant sensitivity was measured by compressing unlubricated tablets and tablets lubricated with 1% magnesium stearate on an instrumented hydraulic press. Sieved isomalt had excellent flow properties but the compactibility was found to be poor whereas the lubricant sensitivity was high. Milling resulted in both a strong increase in compactibility as an effect of the higher surface area for bonding and a decrease in lubricant sensitivity as an effect of the higher surface area to be coated with magnesium stearate. However, the flow properties of milled isomalt were too bad for use as filler-binder in direct compaction. Just as could be expected, agglomeration of milled isomalt by fluid bed agglomeration improved flowability. The good compaction properties and the low lubricant sensitivity were maintained. This effect is caused by an early fragmentation of the agglomerated material during the compaction process, producing clean, lubricant-free particles and a high surface for bonding. The different GPS/GPM ratios of the agglomerated isomalt types studied had no significant effect on the compaction properties. PMID:19327398

  4. Stabilization of compactible waste

    SciTech Connect

    Franz, E.M.; Heiser, J.H. III; Colombo, P.

    1990-09-01

    This report summarizes the results of series of experiments performed to determine the feasibility of stabilizing compacted or compactible waste with polymers. The need for this work arose from problems encountered at disposal sites attributed to the instability of this waste in disposal. These studies are part of an experimental program conducted at Brookhaven National Laboratory (BNL) investigating methods for the improved solidification/stabilization of DOE low-level wastes. The approach taken in this study was to perform a series of survey type experiments using various polymerization systems to find the most economical and practical method for further in-depth studies. Compactible dry bulk waste was stabilized with two different monomer systems: styrene-trimethylolpropane trimethacrylate (TMPTMA) and polyester-styrene, in laboratory-scale experiments. Stabilization was accomplished by wetting or soaking compactible waste (before or after compaction) with monomers, which were subsequently polymerized. Three stabilization methods are described. One involves the in-situ treatment of compacted waste with monomers in which a vacuum technique is used to introduce the binder into the waste. The second method involves the alternate placement and compaction of waste and binder into a disposal container. In the third method, the waste is treated before compaction by wetting the waste with the binder using a spraying technique. A series of samples stabilized at various binder-to-waste ratios were evaluated through water immersion and compression testing. Full-scale studies were conducted by stabilizing two 55-gallon drums of real compacted waste. The results of this preliminary study indicate that the integrity of compacted waste forms can be readily improved to ensure their long-term durability in disposal environments. 9 refs., 10 figs., 2 tabs.

  5. Development of infrared Echelle spectrograph and mid-infrared heterodyne spectrometer on a small telescope at Haleakala, Hawaii for planetary observation

    NASA Astrophysics Data System (ADS)

    Sakanoi, Takeshi; Kasaba, Yasumasa; Kagitani, Masato; Nakagawa, Hiromu; Kuhn, Jeff; Okano, Shoichi

    2014-08-01

    We report the development of infrared Echelle spectrograph covering 1 - 4 micron and mid-infrared heterodyne spectrometer around 10 micron installed on the 60-cm telescope at the summit of Haleakala, Hawaii (alt.=3000m). It is essential to carry out continuous measurement of planetary atmosphere, such as the Jovian infrared aurora and the volcanoes on Jovian satellite Io, to understand its time and spatial variations. A compact and easy-to-use high resolution infrared spectrometer provide the good opportunity to investigate these objects continuously. We are developing an Echelle spectrograph called ESPRIT: Echelle Spectrograph for Planetary Research In Tohoku university. The main target of ESPRIT is to measure the Jovian H3+ fundamental line at 3.9 micron, and H2 nu=1 at 2.1 micron. The 256x256 pixel CRC463 InSb array is used. An appropriate Echelle grating is selected to optimize at 3.9 micron and 2.1 micron for the Jovian infrared auroral observations. The pixel scale corresponds to the atmospheric seeing (0.3 arcsec/pixel). This spectrograph is characterized by a long slit field-of-view of ~ 50 arcsec with a spectral resolution is over 20,000. In addition, we recently developed a heterodyne spectrometer called MILAHI on the 60 cm telescope. MILAHI is characterized by super high-resolving power (more than 1,500,000) covering from 7 - 13 microns. Its sensitivity is 2400 K at 9.6 micron with a MCT photo diode detector of which bandwidth of 3000 MHz. ESPRIT and MILAHI is planned to be installed on 60 cm telescope is planned in 2014.

  6. The Ultraviolet Spectrograph on the Europa Mission (Europa-UVS)

    NASA Astrophysics Data System (ADS)

    Retherford, K. D.; Gladstone, R.; Greathouse, T. K.; Steffl, A.; Davis, M. W.; Feldman, P. D.; McGrath, M. A.; Roth, L.; Saur, J.; Spencer, J. R.; Stern, S. A.; Pope, S.; Freeman, M. A.; Persyn, S. C.; Araujo, M. F.; Cortinas, S. C.; Monreal, R. M.; Persson, K. B.; Trantham, B. J.; Versteeg, M. H.; Walther, B. C.

    2015-12-01

    NASA's Europa multi-flyby mission is designed to provide a diversity of measurements suited to enrich our understanding of the potential habitability of this intriguing ocean world. The Europa mission's Ultraviolet Spectrograph, Europa-UVS, is the sixth in a series of successful ultraviolet imaging spectrographs (Rosetta-Alice, New Horizons Pluto-Alice, LRO-LAMP) and, like JUICE-UVS (now under Phase B development), is largely based on the most recent of these to fly, Juno-UVS. Europa-UVS observes photons in the 55-210 nm wavelength range, at moderate spectral and spatial resolution along a 7.5° slit. Three distinct apertures send light to the off-axis telescope mirror feeding the long-slit spectrograph: i) a main entrance airglow port is used for most observations (e.g., airglow, aurora, surface mapping, and stellar occultations); ii) a high-spatial-resolution port consists of a small hole in an additional aperture door, and is used for detailed observations of bright targets; and iii) a separate solar port allows for solar occultations, viewing at a 60° offset from the nominal payload boresight. Photon event time-tagging (pixel list mode) and programmable spectral imaging (histogram mode) allow for observational flexibility and optimal science data management. As on Juno-UVS, the effects of penetrating electron radiation on electronic parts and data quality are mitigated through contiguous shielding, filtering of pulse height amplitudes, management of high-voltage settings, and careful use of radiation-hard parts. The science goals of Europa-UVS are to: 1) Determine the composition & chemistry, source & sinks, and structure & variability of Europa's atmosphere, from equator to pole; 2) Search for and characterize active plumes in terms of global distribution, structure, composition, and variability; 3) Explore the surface composition & microphysics and their relation to endogenic & exogenic processes; and 4) Investigate how energy and mass flow in the Europa

  7. Precision spectroscopy with a frequency-comb-calibrated solar spectrograph

    NASA Astrophysics Data System (ADS)

    Doerr, H.-P.

    2015-06-01

    The measurement of the velocity field of the plasma at the solar surface is a standard diagnostic tool in observational solar physics. Detailed information about the energy transport as well as on the stratification of temperature, pressure and magnetic fields in the solar atmosphere are encoded in Doppler shifts and in the precise shape of the spectral lines. The available instruments deliver data of excellent quality and precision. However, absolute wavelength calibration in solar spectroscopy was so far mostly limited to indirect methods and in general suffers from large systematic uncertainties of the order of 100 m/s. During the course of this thesis, a novel wavelength calibration system based on a laser frequency comb was deployed to the solar Vacuum Tower Telescope (VTT), Tenerife, with the goal of enabling highly accurate solar wavelength measurements at the level of 1 m/s on an absolute scale. The frequency comb was developed in a collaboration between the Kiepenheuer-Institute for Solar Physics, Freiburg, Germany and the Max Planck Institute for Quantum Optics, Garching, Germany. The efforts cumulated in the new prototype instrument LARS (Lars is an Absolute Reference Spectrograph) for solar precision spectroscopy which is in preliminary scientific operation since~2013. The instrument is based on the high-resolution echelle spectrograph of the VTT for which feed optics based on single-mode optical fibres were developed for this project. The setup routinely achieves an absolute calibration accuracy of 60 cm/s and a repeatability of 2.5 cm/s. An unprecedented repeatability of only 0.32 cm/s could be demonstrated with a differential calibration scheme. In combination with the high spectral resolving power of the spectrograph of 7x10^5 and virtually absent internal scattered light, LARS provides a spectral purity and fidelity that previously was the domain of Fourier-transform spectrometers only. The instrument therefore provides unique capabilities for

  8. Hobby-Eberly Telescope low-resolution spectrograph

    NASA Astrophysics Data System (ADS)

    Hill, Gary J.; Nicklas, Harald E.; MacQueen, Phillip J.; Tejada, Carlos; Cobos Duenas, Francisco J.; Mitsch, Wolfgang

    1998-07-01

    The Hobby-Eberly Telescope (HET) is a revolutionary large telescope of 9.2 meter aperture, located in West Texas at McDonald Observatory. First light was obtained on December 11, 1996. The start of scientific operations is expected in the late summer of 1998. The Low Resolution Spectrograph [LRS, an international collaboration between the University of Texas at Austin (UT), the Instituto de Astronomia de la Universidad Nacional Autonoma de Mexico (IAUNAM), Stanford University, Ludwig-Maximillians-Universitat, Munich (USM), and Georg- August-Universitat, Gottingen (USG)] is a high throughput, imaging spectrograph which rides on the HET tracker at prime focus. The LRS will be the first HET facility instrument. The remote location and the tight space and weight constraints make the LRS a challenging instrument, built on a limited budget. The optics were partially constructed in Mexico at IAUNAM, the mechanics in Germany, and the camera and CCD system in Texas. The LRS is a grism spectrograph with three modes of operation: imaging, longslit, and multi-object. The field of view of the HET is 4 arcmin in diameter, and the LRS will have a 13-slitlet Multi Object Spectroscopy (MOS) unit covering this field. The MOS unit is based on miniature components and is remotely configurable under computer control. Resolving powers between R equals (lambda) /(Delta) (lambda) approximately 600 and 3000 with a 1 arcsecond wide slit will be achieved with a variety of grisms, of which two can be carried by the instrument at any one time. The CCD is a Ford Aerospace 3072 X 1024 device with 15 micrometer pixels, and the image scale is approximately 0.25 arcsec per pixel. Here we present a detailed description of the LRS, and provide an overview of the optical and mechanical aspects of its design (which are discussed in detail elsewhere in these proceedings). Fabrication, assembly, and testing of the LRS will be completed by mid 1998. First light for the LRS on the HET is expected in the

  9. Design and Build a Compact Raman Sensor for Identification of Chemical Composition

    NASA Technical Reports Server (NTRS)

    Garcia, Christopher S.; Abedin, M. Nurul; Ismail, Syed; Sharma, Shiv K.; Misra, Anupam K.; Sandford, Stephen P.; Elsayed-Ali, Hani

    2008-01-01

    A compact remote Raman sensor system was developed at NASA Langley Research Center. This sensor is an improvement over the previously reported system, which consisted of a 532 nm pulsed laser, a 4-inch telescope, a spectrograph, and an intensified charge-coupled devices (CCD) camera. One of the attractive features of the previous system was its portability, thereby making it suitable for applications such as planetary surface explorations, homeland security and defense applications where a compact portable instrument is important. The new system was made more compact by replacing bulky components with smaller and lighter components. The new compact system uses a smaller spectrograph measuring 9 x 4 x 4 in. and a smaller intensified CCD camera measuring 5 in. long and 2 in. in diameter. The previous system was used to obtain the Raman spectra of several materials that are important to defense and security applications. Furthermore, the new compact Raman sensor system is used to obtain the Raman spectra of a diverse set of materials to demonstrate the sensor system's potential use in the identification of unknown materials.

  10. Spectrographic Polarimeter and Method of Recording State of Polarity

    NASA Technical Reports Server (NTRS)

    Sparks, William B. (Inventor)

    2015-01-01

    A single-shot real-time spectropolarimeter for use in astronomy and other sciences that captures and encodes some or all of the Stokes polarization parameters simultaneously using only static, robust optical components with no moving parts is described. The polarization information is encoded onto the spectrograph at each wavelength along the spatial dimension of the 2D output data array. The varying embodiments of the concept include both a two-Stokes implementation (in which any two of the three Stokes polarization parameters are measured) and a full Stokes implementation (in which all three of the Stokes polarization parameters are measured), each of which is provided in either single beam or dual beam forms.

  11. SPRED spectrograph upgrade: high resolution grating and improved absolute calibrations

    SciTech Connect

    Stratton, B.C.; Fonck, R.J.; Ida, K.; Jaehnig, K.P.; Ramsey, A.T.

    1986-05-01

    Two improvements to the SPRED multichannel VUV spectrographs used on the TFTR and PBX tokamaks have been made: (1) A new 2100-g/mm grating covering the 100 to 320 A region with 0.4 A resolution (FWHM) has been added to the existing 450 g/mm grating (100 to 1100 A with 2 A resolution), and (2) the TFTR SPRED has been absolutely calibrated using synchrotron radiation from the NBS SURF II facility, while the PBX system has been calibrated using conventional branching ratios along with line ratios from charge-exchange-recombination-excited lines. The availability of high resolution spectra in the 100 to 320 A range provides improved measurements of metallic ion emissions and, when the instrument views across a neutral beam as in PBX, allows carbon and oxygen densities to be measured via charge exchange recombination spectroscopy.

  12. Calibration and operation of the Faint Object Spectrograph

    NASA Technical Reports Server (NTRS)

    Harms, R.; Beaver, E.; Burbidge, E.; Hier, R.; Allen, R.; Angel, R.; Bartko, F.; Bohlin, R.; Ford, H.; Davidson, A.

    1984-01-01

    The design and basic performance characteristics of the Faint Object Spectrograph (FOS), one of five instruments built for use on the Space Telescope observatory, is summarized briefly. The results of the recently completed instrument-level calibration are presented with special emphasis on issues affecting plans for FOS astronomical observations. Examples include such fundamental characteristics as: limiting magnitudes (system sensitivity and noise figures), spectral coverage and resolution, scattered light properties, and instrumental polarization and modulation efficiencies. Also gated toward intended users, a rather detailed description of FOS operating modes is given. The discussion begins with the difficulties anticipated during target acquisition and their hoped-for resolution. Both the 'normal' spectroscopic operating modes of the FOS and its 'exotic' features (e.g. spectropolarimetric, time-tagged, and time-resolved modes) are presented. The paper concludes with an overview of the activities to assure proper alignment and operation of the FOS within the entire Space Telescope system (orbital and ground-based).

  13. Telescope baffle performance for Lyman Far Ultraviolet Spectrographic Explorer

    NASA Astrophysics Data System (ADS)

    Morbey, Christopher; Hutchings, J. B.

    1993-07-01

    The Lyman Far Ultraviolet Spectrographic Explorer telescope is a Wolter type II glancing incidence design with an aperture of 64 cm. Because the spacecraft is required to guide on stars fainter than m(v) = 16, a visible light baffle is necessary to protect the FOV from the stray light that results from out-of-field bright sources. Such a baffle system is described here. Total point-source transmittances are computed for incident beams in the range 0-70 deg. Estimates for background brightness on the detector are made for the contribution from direct sunlight and earthshine. Scattering from the black surfaces of the baffle, the vanes, and diffraction at the structure's edges are taken into consideration.

  14. Status of RAISE, the Rapid Acquisition Imaging Spectrograph Experiment

    NASA Astrophysics Data System (ADS)

    Laurent, Glenn T.; Hassler, D. M.; DeForest, C.; Ayres, T. R.; Davis, M.; De Pontieu, B.; Schuehle, U.; Warren, H.

    2013-07-01

    The Rapid Acquisition Imaging Spectrograph Experiment (RAISE) sounding rocket payload is a high speed scanning-slit imaging spectrograph designed to observe the dynamics and heating of the solar chromosphere and corona on time scales as short as 100 ms, with 1 arcsec spatial resolution and a velocity sensitivity of 1-2 km/s. The instrument is based on a new class of UV/EUV imaging spectrometers that use only two reflections to provide quasi-stigmatic performance simultaneously over multiple wavelengths and spatial fields. The design uses an off-axis parabolic telescope mirror to form a real image of the sun on the spectrometer entrance aperture. A slit then selects a portion of the solar image, passing its light onto a near-normal incidence toroidal grating, which re-images the spectrally dispersed radiation onto two array detectors. Two full spectral passbands over the same one-dimensional spatial field are recorded simultaneously with no scanning of the detectors or grating. The two different spectral bands (1st-order 1205-1243Å and 1526-1564Å) are imaged onto two intensified Active Pixel Sensor (APS) detectors whose focal planes are individually adjusted for optimized performance. The telescope and grating are coated with B4C to enhance short wavelength (2nd order) reflectance, enabling the instrument to record the brightest lines between 602-622Å and 761-780Å at the same time. RAISE reads out the full field of both detectors at 5-10 Hz, allowing us to record over 1,500 complete spectral observations in a single 5-minute rocket flight, opening up a new domain of high time resolution spectral imaging and spectroscopy. We present an overview of the project, a summary of the maiden flight results, and an update on instrument status.Abstract (2,250 Maximum Characters): The Rapid Acquisition Imaging Spectrograph Experiment (RAISE) sounding rocket payload is a high speed scanning-slit imaging spectrograph designed to observe the dynamics and heating of the solar

  15. A photometric and spectrographic study of BP Pegasi

    SciTech Connect

    Kim, C.; Mcnamara, D.H.; Joner, M.D. Brigham Young Univ., Provo, UT )

    1989-11-01

    Photometric (uvby beta) and spectrographic observations of the dwarf Cepheid BP Peg are discussed. The observations are used to derive a reddening value of E(b-y) = 0.067 m. An effective temperature of 7470 K, a mean surface gravity, log g = 3.85, and a Fe/H abundance ratio of - 0.08 are obtained. Pulsation theory and stellar model sequences yield M(bol) = 1.4 m, mass = 1.85 solar masses, and age = 1.3 X 10 to the 9th yrs. Also, the radial-velocity data show a mean radial velocity of - 30 km/s and a total velocity range of 36 km/s. 14 refs.

  16. Analytical precision of one-sixth order semiquantitative spectrographic analysis

    USGS Publications Warehouse

    Motooka, J.M.; Grimes, D.J.

    1976-01-01

    Over 2,700 separate analyses were made on 22 different geologic samples selected to cover wide concentration ranges for the 30 elements studied. The precision for low, medium, and high concentrations of each element determined is represented by superimposed frequency diagrams and displays the frequency of reported values occurring within one-sixth order reporting intervals about the mean.Results are derived from mixed analyst and instrument conditions with no controls enforced other than randomization of samples. The precision of the six-step (one-sixth order) semiquantitative spectrographic analysis utilized by the Denver-based mobile laboratories exceeds that which is necessary for exploration geochemistry. Disallowing results obtained near the detection levels, the repeatability of the method, in general, is shown to be within on adjoining reporting interval on each side of the mean, 83 percent of the time, and within two adjoining reporting intervals on each side of the mean 96 percent of the time.

  17. Cosmic Origins Spectrograph: On-Orbit Performance of Target Acquisitions

    NASA Astrophysics Data System (ADS)

    Penton, Steven V.

    2010-07-01

    COS is a slit-less spectrograph with a very small aperture (R=1.2500). To achieve the desired wavelength accuracies, HST+COS must center the target to within 0.100 of the center of the aperture for the FUV channel, and 0.0400 for NUV. During SMOV and early Cycle 17 we fine-tuned the COS target acquisition (TA) procedures to exceed this accuracy for all three COS TA modes; NUV imaging, NUV spectroscopic, and FUV spectroscopic. In Cycle 17, we also adjusted the COSto- FGS offsets in the SIAF file. This allows us to recommend skipping the time consuming ACQ/SEARCH in cases where the target coordinates are well known. Here we will compare the on-orbit performance of all COS TA modes in terms of centering accuracy, efficiency, and required signal-to-noise (S/N).

  18. Ultraviolet Spectrograph Concepts for the Outer Planet Flagship Mission

    NASA Astrophysics Data System (ADS)

    Retherford, Kurt D.; Stern, A.; Slater, D. C.; Gladstone, R.; Davis, M. W.; Parker, J. W.; Steffl, A. J.; Greathouse, T. K.; Cunningham, N. J.; Spencer, J. R.

    2008-09-01

    SwRI's Alice line of ultraviolet spectrographs (UVS) is founded on a lightweight, low power, and highly capable and versatile instrument design. With generally small changes in detector photocathode, detector pixel size, slit size and shape, optical coatings, pinhole aperture implementations, and other minor tweaks we've found a wide variety of applications for the Alice design, to date, at comets (Rosetta/Alice), Pluto (New Horizons/Alice), Luna (LRO/LAMP), and Jupiter (Juno/UVS). The SwRI UVS heritage includes very broad experience and strong performance to date on the Rosetta (Phase E; successful Mars flyby), New Horizons (Phase E; successful Jupiter flyby), LRO (Phase D; mated to the spacecraft), and Juno (Phase C) missions. Alice's high capability, low resource requirements, and our experience with Juno-based radiation environment and NH-based outer solar system environment requirements make this UVS a good choice for the Outer Planet Flagship mission concepts.

  19. Micro-ultraviolet spectrograph (Micro-UVS). Final design report

    SciTech Connect

    Stern, S.A.; Slater, D.C.

    1994-04-30

    In this report, the authors present a low-mass (<2 kg), low-power (approximately 2 W), and low-cost (< $0.5M) Far UV spectrometer design, capable of performing high-resolution ({lambda}/{delta}{lambda} approximately equal to 100-200) spectroscopy of planetary atmospheres in the extreme ultraviolet wavelength regime (700 {angstrom} < {lambda} < 1500 {angstrom}). This spectrograph, referred to in this report as the MicroUVS, is in part based on the integrated UV/VIS/IR Pluto Fast Flyby (PFF) design being developed for NASA, but is tailored to be a stand-alone instrument suitable for future BMDO/LLNL missions. Design objectives and performance of the spectrometer are discussed in detail.

  20. The Infrared Imaging Spectrograph (IRIS) for TMT: instrument overview

    NASA Astrophysics Data System (ADS)

    Moore, Anna M.; Larkin, James E.; Wright, Shelley A.; Bauman, Brian; Dunn, Jennifer; Ellerbroek, Brent; Phillips, Andrew C.; Simard, Luc; Suzuki, Ryuji; Zhang, Kai; Aliado, Ted; Brims, George; Canfield, John; Chen, Shaojie; Dekany, Richard; Delacroix, Alex; Do, Tuan; Herriot, Glen; Ikenoue, Bungo; Johnson, Chris; Meyer, Elliot; Obuchi, Yoshiyuki; Pazder, John; Reshetov, Vladimir; Riddle, Reed; Saito, Sakae; Smith, Roger; Sohn, Ji Man; Uraguchi, Fumihiro; Usuda, Tomonori; Wang, Eric; Wang, Lianqi; Weiss, Jason; Wooff, Robert

    2014-08-01

    We present an overview of the design of IRIS, an infrared (0.84 - 2.4 micron) integral field spectrograph and imaging camera for the Thirty Meter Telescope (TMT). With extremely low wavefront error (<30 nm) and on-board wavefront sensors, IRIS will take advantage of the high angular resolution of the narrow field infrared adaptive optics system (NFIRAOS) to dissect the sky at the diffraction limit of the 30-meter aperture. With a primary spectral resolution of 4000 and spatial sampling starting at 4 milliarcseconds, the instrument will create an unparalleled ability to explore high redshift galaxies, the Galactic center, star forming regions and virtually any astrophysical object. This paper summarizes the entire design and basic capabilities. Among the design innovations is the combination of lenslet and slicer integral field units, new 4Kx4k detectors, extremely precise atmospheric dispersion correction, infrared wavefront sensors, and a very large vacuum cryogenic system.

  1. Updated Status and Performance of the Space Telescope Imaging Spectrograph

    NASA Astrophysics Data System (ADS)

    Wolfe, Michael A.; Dixon, W. V.; Mason, E.; Proffitt, C.; Aloisi, A.; Oliveira, C.; Bohlin, R. C.; Osten, R.; Bostroem, K. A.; Zheng, W.; Pascucci, I.; Niemi, S.; York, B.; Sonnentracker, P.; Diaz, R.; Ely, J. C.

    2011-05-01

    A description is provided of the overall performance of the Space Telescope Imaging Spectrograph after Cycle 17 and through the first half of Cycle 18. Most aspects of performance are still found to be consistent with extrapolations of the trends seen during Cycle 17 calibrations. Many of the characteristics of the instrument have changed over time, and we present here an update on its current performance based on the latest Cycle 18 calibration observations. We discuss changes in the CCD and MAMA dark currents, provide updates on the sensitivity of STIS modes, echelle blaze function, discuss changes, if any, in number of hot pixels, flat fields, charge transfer inefficiency, read noise, and spurious charge.

  2. Extreme ultraviolet spectrograph ATM experiment S082B

    NASA Technical Reports Server (NTRS)

    Bartoe, J.-D. F.; Brueckner, G. E.; Purcell, J. D.; Tousey, R.

    1977-01-01

    The extreme-ultraviolet double-dispersion photographic spectrograph for the Apollo Telescope Mount (ATM) experiment S082B on Skylab is described. Novel features were the use of a predisperser grating with a ruling whose spacing varied approximately linearly with distance for the purpose of increasing the instrument speed by reducing the astigmatism and a photoelectric servosystem to stabilize to 1 sec of arc the solar image at various near-limb positions. The 970-3940-A range was covered in two sections with effective resolving power of approximately 30,000 from 1100 A to 1970 A. The spatial resolution was 2 x 60 solar sec of arc. During the Skylab mission 6400 exposures were made with the instrument pointed by an astronaut at selected and recorded solar positions.

  3. Raman Imaging with a Fiber-Coupled Multichannel Spectrograph

    PubMed Central

    Schmälzlin, Elmar; Moralejo, Benito; Rutowska, Monika; Monreal-Ibero, Ana; Sandin, Christer; Tarcea, Nicolae; Popp, Jürgen; Roth, Martin M.

    2014-01-01

    Until now, spatially resolved Raman Spectroscopy has required to scan a sample under investigation in a time-consuming step-by-step procedure. Here, we present a technique that allows the capture of an entire Raman image with only one single exposure. The Raman scattering arising from the sample was collected with a fiber-coupled high-performance astronomy spectrograph. The probe head consisting of an array of 20 × 20 multimode fibers was linked to the camera port of a microscope. To demonstrate the high potential of this new concept, Raman images of reference samples were recorded. Entire chemical maps were received without the need for a scanning procedure. PMID:25420149

  4. The Wide Field Spectrograph (WiFeS)

    NASA Astrophysics Data System (ADS)

    Dopita, Michael; Hart, John; McGregor, Peter; Oates, Patrick; Bloxham, Gabe; Jones, Damien

    2007-08-01

    This paper describes the Wide Field Spectrograph (WiFeS) under construction at the Research School of Astronomy and Astrophysics (RSAA) of the Australian National University (ANU) for the ANU 2.3 m telescope at the Siding Spring Observatory. WiFeS is a powerful integral field, double-beam, concentric, image-slicing spectrograph designed to deliver excellent throughput, wavelength stability, spectrophotometric performance and superb image quality along with wide spectral coverage throughout the 320 950 nm wavelength region. It provides a 25×38 arcsec field with 0.5 arcsec sampling along each of twenty five 38×1 arcsec slitlets. The output format is optimized to match the 4096×4096 pixel CCD detectors in each of two cameras individually optimized for the blue and the red ends of the spectrum, respectively. A process of “interleaved nod-and-shuffle” will be applied to permit quantum noise-limited sky subtraction. Using VPH gratings, spectral resolutions of 3000 and 7000 are provided. The full spectral range is covered in a single exposure at R=3000, and in two exposures in the R=7000 mode. The use of transmissive coated optics, VPH gratings and optimized mirror coatings ensures a throughput (including telescope atmosphere and detector) >30% over a wide spectral range. The concentric image-slicer design ensures an excellent and uniform image quality across the full field. To maximize scientific return, the whole instrument is configured for remote observing, pipeline data reduction, and the accumulation of calibration image libraries.

  5. RAISE (Rapid Acquisition Imaging Spectrograph Experiment): Results and Instrument Status

    NASA Astrophysics Data System (ADS)

    Laurent, Glenn T.; Hassler, Donald; DeForest, Craig; Ayres, Tom; Davis, Michael; DePontieu, Bart; Diller, Jed; Graham, Roy; Schule, Udo; Warren, Harry

    2015-04-01

    We present initial results from the successful November 2014 launch of the RAISE (Rapid Acquisition Imaging Spectrograph Experiment) sounding rocket program, including intensity maps, high-speed spectroheliograms and dopplergrams, as well as an update on instrument status. The RAISE sounding rocket payload is the fastest high-speed scanning-slit imaging spectrograph flown to date and is designed to observe the dynamics and heating of the solar chromosphere and corona on time scales as short as 100-200ms, with arcsecond spatial resolution and a velocity sensitivity of 1-2 km/s. The instrument is based on a class of UV/EUV imaging spectrometers that use only two reflections to provide quasi-stigmatic performance simultaneously over multiple wavelengths and spatial fields. The design uses an off-axis parabolic telescope mirror to form a real image of the sun on the spectrometer entrance aperture. A slit then selects a portion of the solar image, passing its light onto a near-normal incidence toroidal grating, which re-images the spectrally dispersed radiation onto two array detectors. Two full spectral passbands over the same one-dimensional spatial field are recorded simultaneously with no scanning of the detectors or grating. The two different spectral bands (1st-order 1205-1243Å and 1526-1564Å) are imaged onto two intensified Active Pixel Sensor (APS) detectors whose focal planes are individually adjusted for optimized performance. RAISE reads out the full field of both detectors at 5-10 Hz, allowing us to record over 1,500 complete spectral observations in a single 5-minute rocket flight, opening up a new domain of high time resolution spectral imaging and spectroscopy. RAISE is designed to study small-scale multithermal dynamics in active region (AR) loops, explore the strength, spectrum and location of high frequency waves in the solar atmosphere, and investigate the nature of transient brightenings in the chromospheric network.

  6. Design of the CHARIS integral field spectrograph for exoplanet imaging

    NASA Astrophysics Data System (ADS)

    Groff, Tyler D.; Peters, Mary Anne; Kasdin, N. Jeremy; Knapp, Gillian; Galvin, Michael; Carr, Michael; McElwain, Michael W.; Brandt, Timothy; Janson, Markus; Gunn, James E.; Lupton, Robert; Guyon, Olivier; Martinache, Frantz; Jovanovic, Nemanja; Hayashi, Masahiko; Takato, Naruhisa

    2013-09-01

    Princeton University is building an integral field spectrograph (IFS), the Coronagraphic High Angular Resolution Imaging Spectrograph (CHARIS), for integration with the Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) system and the AO188 adaptive optics system on the Subaru telescope. CHARIS and SCExAO will measure spectra of hot, young Jovian planets in a coronagraphic image across J, H, and K bands down to an 80 milliarcsecond inner working angle. SCExAO's coronagraphs and wavefront control system will make it possible to detect companions five orders of magnitude dimmer than their parent star. However, quasi-static speckles in the image contaminate the signal from the planet. In an IFS this also causes uncertainty in the spectra due to diffractive cross-contamination, commonly referred to as crosstalk. Post-processing techniques can subtract these speckles, but they can potentially skew spectral measurements, become less effective at small angular separation, and at best can only reduce the crosstalk down to the photon noise limit of the contaminating signal. CHARIS will address crosstalk effects of a high contrast image through hardware design, which drives the optical and mechanical design of the assembly. The work presented here sheds light on the optical and mechanical considerations taken in designing the IFS to provide high signal-to-noise spectra in a coronagraphic image from and extreme adaptive optics image. The design considerations and lessons learned are directly applicable to future exoplanet instrumentation for extremely large telescopes and space observatories capable of detecting rocky planets in the habitable zone.

  7. Cosmic Origins Spectrograph: Servicing Mission Observatory Verification Overview

    NASA Astrophysics Data System (ADS)

    Keyes, Charles D.; Sahnow, D.; Aloisi, A.; Biagetti, C.; Osterman, S.; Froning, C.; Penton, S.; Green, J.; Oliveira, C.; Osten, R.; Niemi, S.; STScI COS Team; COS IDT Team

    2010-01-01

    The Cosmic Origins Spectrograph (COS) was installed onboard the Hubble Space Telescope (HST) in May, 2009 as part of the most recent servicing mission (SM4). COS is optimized for observing faint point sources at moderate spectral resolutions and is the most sensitive UV spectrograph ever flown on HST. The FUV channel, which is 10 to 30 times more sensitive than STIS, covers the wavelength range from 1150 to 1800 A with medium resolution gratings (G130M/G160M) and from 900 to 2400 A. with a low resolution grating (G140L). The medium resolution gratings in the NUV channel (G185M/G225M/G285M) cover 1700 to 3200 A., while the low resolution grating (G230L) covers 1700 to 3200 A. As part of the overall HST Servicing Mission Observatory Verification (SMOV), COS on-orbit functionality was verified via an extensive set of 34 observing programs comprising nearly 2800 individual exposures. We present a thorough discussion of the organization, inter-relationships, and dependencies of the programs in the verification plan. Sequential activities were executed that concentrated on the general areas of initial instrument checkout; detector HV turn-on and operation; initial detector characterization; NUV focus and alignment; FUV focus and alignment; initial target acquisition verification; wavelength calibration; and thorough target acquisition assessment, all leading to enabling of basic science functionality. Finally science-related calibrations and verifications were performed including flux calibration, flat field characterization, spectroscopic performance verification, high S/N operation, and thermal and structural stability measurements. Several companion presentations describe results from specific programs and verification areas in more detail.

  8. DMD-based programmable wide field spectrograph for Earth observation

    NASA Astrophysics Data System (ADS)

    Zamkotsian, Frédéric; Lanzoni, Patrick; Liotard, Arnaud; Viard, Thierry; Costes, Vincent; Hébert, Philippe-Jean

    2015-03-01

    In Earth Observation, Universe Observation and Planet Exploration, scientific return could be optimized in future missions using MOEMS devices. In Earth Observation, we propose an innovative reconfigurable instrument, a programmable wide-field spectrograph where both the FOV and the spectrum could be tailored thanks to a 2D micromirror array (MMA). For a linear 1D field of view (FOV), the principle is to use a MMA to select the wavelengths by acting on intensity. This component is placed in the focal plane of a first grating. On the MMA surface, the spatial dimension is along one side of the device and for each spatial point, its spectrum is displayed along the perpendicular direction: each spatial and spectral feature of the 1D FOV is then fully adjustable dynamically and/or programmable. A second stage with an identical grating recomposes the beam after wavelengths selection, leading to an output tailored 1D image. A mock-up has been designed, fabricated and tested. The micromirror array is the largest DMD in 2048 x 1080 mirrors format, with a pitch of 13.68μm. A synthetic linear FOV is generated and typical images have been recorded o at the output focal plane of the instrument. By tailoring the DMD, we could modify successfully each pixel of the input image: for example, it is possible to remove bright objects or, for each spatial pixel, modify the spectral signature. The very promising results obtained on the mock-up of the programmable wide-field spectrograph reveal the efficiency of this new instrument concept for Earth Observation.

  9. Galactic Archaeology with the Subaru Prime Focus Spectrograph

    NASA Astrophysics Data System (ADS)

    Chiba, Masashi; Cohen, Judith; Wyse, Rosemary

    2015-08-01

    We present our Galactic Archaeology survey plan with the Prime Focus Spectrograph (PFS) for Subaru. PFS is a massively-multiplexed, fiber-fed optical and near-infrared 3-arm spectrograph (N_fiber = 2,400, 380 < lambda < 1260 nm, 1.3 degree diameter hexagonal field, low- and medium-resolution modes of R = 2,000-3,000 and 5,000, respectively), offering us unique opportunities in survey astronomy. Following successful design reviews, the instrument is now under construction with first light anticipated in 2018. In the Galactic Archaeology program, for which we expect to have about 100 nights over 5 years, radial velocities and chemical abundances of stars in the Milky Way and M31 will be used to infer the past assembly histories of these galaxies and the structure of their dark matter halos. Data will be secured for numerous stars in the Galactic thick-disk, halo and tidal streams as faint as V = 22 mag, including stars with V < 20 mag to complement the goals of the Gaia mission. A medium-resolution mode with R = 5,000 to be implemented in the red arm will allow the measurement of multiple alpha-element abundances and more precise velocities for Galactic stars, elucidating the detailed chemo-dynamical structure and evolution of each of the main stellar components of the Milky Way Galaxy and of its dwarf spheroidal galaxies. The M31 campaign will target red giant branch stars with 21.5 < V < 22.5 mag, obtaining radial velocities and metallicities over an unprecedented large area of its stellar halo. In synergy with these planned PFS survey, the coordinated imaging surveys with Hyper Suprime Cam are going on over wide areas of the Galactic satellites and the M31 halo, based on the combination of broad-band and narrow-band filters to separate candidate giants from foreground dwarfs as spectroscopic targets.

  10. A new high-speed solar radio spectrograph for meter and decameter wavelengths

    NASA Technical Reports Server (NTRS)

    Mosier, S. R.; Fainberg, J.

    1974-01-01

    The design and characteristics of a high resolution, digital solar spectrograph are discussed. The spectrometer operates in the 10 to 80 MHz range. The primary considerations in the design of the spectrograph were: (1) optimun sensitivity, (2) wide dynamic range, (3) flexibility in time and frequency resolution, and (4) modern data handling techniques with a simple computer interface.

  11. Slit-mask, acquisition, and guiding zone mechanisms of the ESOPO spectrograph

    NASA Astrophysics Data System (ADS)

    Pedrayes, M.; Gonzalez, J.; Luna, E.; Quiroz, F.; Sierra, G.; Arroyo, M.; Avila, G.; Cobos, F.; Colorado, E.; Córdova, A.; Costero, R.; Chapa, O.; Echevarria, J.; Farah, A.; García, B.; Garfias, F.; Guisa, G.; Granados, F.; Martínez, B.; Michel, R.; Murillo, F.; Murillo, J.; Quechol, S.; Tejada, C.

    2008-07-01

    This work presents the specifications, requirements, design, finite element analysis and results of the assembled subsystems: slit-mask, and the acquisition and guiding zone mechanisms of the ESOPO spectrograph. This spectrograph is a project of the Institute of Astronomy, National University of Mexico.

  12. A Student Assembled Spectrograph with a CCD Detector to Assist with Students' Understanding of Spectrometry

    ERIC Educational Resources Information Center

    Grove, T. T.; Masters, M. F.

    2007-01-01

    To help students develop an understanding of the proper use and function of spectrographs and monochromators we describe a student-assembled spectrograph using a "webcam" detector. The apparatus also works well as a low-cost demonstration, helping students make connections between an atomic spectrum observed by eye and a plot of the relative…

  13. Scientific Design of a High Contrast Integral Field Spectrograph for the Subaru Telescope

    NASA Technical Reports Server (NTRS)

    McElwain, Michael W.

    2012-01-01

    Ground based telescopes equipped with adaptive optics systems and specialized science cameras are now capable of directly detecting extrasolar planets. We present the scientific design for a high contrast integral field spectrograph for the Subaru Telescope. This lenslet based integral field spectrograph will be implemented into the new extreme adaptive optics system at Subaru, called SCExAO.

  14. Prime Focus Spectrograph: A very wide-field, massively multiplexed, optical & near-infrared spectrograph for Subaru Telescope

    NASA Astrophysics Data System (ADS)

    Tamura, Naoyuki

    This short article is about Prime Focus Spectrograph (PFS), a very wide-field, massively-multiplexed, and optical & near-infrared (NIR) spectrograph as a next generation facility instrument on Subaru Telescope. More details and updates are available on the PFS official website (http://pfs.ipmu.jp), blog (http://pfs.ipmu.jp/blog/), and references therein. The project, instrument, & timeline PFS will position 2400 fibers to science targets or blank sky in the 1.3 degree field on the Subaru prime focus. These fibers will be quickly (~60sec) reconfigurable and feed the photons during exposures to the Spectrograph System (SpS). SpS consists of 4 modules each of which accommodate ~600 fibers and deliver spectral images ranging from 380nm to 1260nm simultaneously at one exposure via the 3 arms of blue, red, and NIR cameras. The instrument development has been undertaken by the international collaboration at the initiative of Kavli IPMU. The project is now going into the construction phase aiming at system integration and on-sky engineering observations in 2017-2018, and science operation in 2019. The survey design has also been under development envisioning a survey spanning ~300 nights over ~5 years in the framework of Subaru Strategic Program (SSP). The key science areas are: Cosmology, galaxy/AGN evolution, and Galactic Archaeology (GA) (Takada et al. 2014). The cosmology program will be to constrain the nature of dark energy via a survey of emission line galaxies over a comoving volume of 10 Gpc3 at z=0.8-2.4. In the galaxy/AGN program, the wide wavelength coverage of PFS as well as the large field of view will be exploited to characterize the galaxy populations and its clustering properties over a wide redshift range. A survey of color-selected galaxies/AGN at z = 1-2 will be conducted over 20 square degrees yielding a fair sample of galaxies with stellar masses down to ~1010 M ⊙. In the GA program, radial velocities and chemical abundances of stars in the Milky

  15. Prime Focus Spectrograph: A very wide-field, massively multiplexed, optical & near-infrared spectrograph for Subaru Telescope

    NASA Astrophysics Data System (ADS)

    TAMURA, NAOYUKI

    2015-08-01

    PFS (Prime Focus Spectrograph), a next generation facility instrument on Subaru, is a very wide-field, massively-multiplexed, and optical & near-infrared spectrograph. Exploiting the Subaru prime focus, 2400 reconfigurable fibers will be distributed in the 1.3 degree field. The spectrograph will have 3 arms of blue, red, and near-infrared cameras to simultaneously observe spectra from 380nm to 1260nm at one exposure. The development of this instrument has been undertaken by the international collaboration at the initiative of Kavli IPMU. The project is now going into the construction phase aiming at system integration and on-sky commissioning in 2017-2018, and science operation in 2019. In parallel, the survey design has also been developed envisioning a Subaru Strategic Program (SSP) that spans roughly speaking 300 nights over 5 years. The major science areas are three-folds: Cosmology, galaxy/AGN evolution, and Galactic archaeology (GA). The cosmology program will be to constrain the nature of dark energy via a survey of emission line galaxies over a comoving volume of ~10 Gpc^3 in the redshift range of 0.8 < z < 2.4. In the GA program, radial velocities and chemical abundances of stars in the Milky Way, dwarf spheroidal galaxies, and M31 will be used to understand the past assembly histories of those galaxies and the structures of their dark matter halos. Spectra will be taken for ~1 million stars as faint as V = 22 therefore out to large distances from the Sun. For the extragalactic program, our simulations suggest the wide wavelength coverage of PFS will be particularly powerful in probing the galaxy populations and its clustering properties over a wide redshift range. We will conduct a survey of color-selected 1 < z < 2 galaxies and AGN over 20 square degrees down to J = 23.4, yielding a fair sample of galaxies with stellar masses above ˜10^10 solar masses. Further, PFS will also provide unique spectroscopic opportunities even in the era of Euclid, LSST

  16. Integration and test activities for the SUMIRE prime focus spectrograph at LAM

    NASA Astrophysics Data System (ADS)

    Madec, F.; Jaquet, Marc; Pascal, Sandrine; Bozier, A.; Le Mignant, David; Vives, S.; Ferrand, D.; Pegot-Ogier, T.; Arthaud, G.; Golebiowski, M.; Sugai, H.; Tamura, N.; Gunn, J.; Smee, S.; Oliveira, L.

    2014-07-01

    The Prime Focus Spectrograph (PFS) of the Subaru Measurement of Images and Redshifts (SuMIRe) project for Subaru telescope consists in four identical spectrographs feed by 600 fibers each. Each spectrograph is composed by an optical entrance unit that creates a collimated beam and distributes the light to three channels, two visible and one near infrared. We present here the integration process of the first spectrograph channel. The verification requirements, the specific integration requirements and the product tree are the main drivers from the top plan for the Assembly Integration and Test (AIT) development process. We then present the AIT flow-down, the details for the AIT processes as well as opto-mechanical alignment procedures and tests setup. In parallel, we are developing and validating dedicated tools to secure and facilitate the AIT activities, as we have to assemble eight visible cameras, integrate and align four fiber slits, integrate and align the components of four spectrographs.

  17. An efficient low- and moderate-resolution spectrograph for the Hale telescope

    NASA Technical Reports Server (NTRS)

    Oke, J. B.; Gunn, J. E.

    1982-01-01

    A new low-to-moderate resolution spectrograph has been designed and built for the Cassegrain focus of the Hale 5.08-meter telescope. To maximize efficiency, resolution, and wavelength coverage the light is divided into two spectra regions by a dichroic filter behind the entrance slit, after which there are two completely separate spectrographs. The blue spectrograph operates from 3200 A to 5200 A while the red one goes from 5200 A to 10,000 A. The red detector is an 800 x 800 TI CCD while the blue detector is a 320 x 512 RCA CCD or a Shectrograph image pulse-counting system. A Boksenberg IPCS can also be mounted on the blue camera. The overall efficiency of the Cassegrain telescope, spectrographs, and CCD's combined, ranges from 5 percent to 13 percent between 3600 A and 8200 A. The spectrograph is usable from 3200 A to 10,400 A.

  18. Progress with the Prime Focus Spectrograph for the Subaru Telescope: a massively multiplexed optical and near-infrared fiber spectrograph

    NASA Astrophysics Data System (ADS)

    Sugai, Hajime; Tamura, Naoyuki; Karoji, Hiroshi; Shimono, Atsushi; Takato, Naruhisa; Kimura, Masahiko; Ohyama, Youichi; Ueda, Akitoshi; Aghazarian, Hrand; de Arruda, Marcio V.; Barkhouser, Robert H.; Bennett, Charles L.; Bickerton, Steve; Bozier, Alexandre; Braun, David F.; Bui, Khanh; Capocasale, Christopher M.; Carr, Michael A.; Castilho, Bruno; Chang, Yin-Chang; Chen, Hsin-Yo; Chou, Richard C. Y.; Dawson, Olivia R.; Dekany, Richard G.; Ek, Eric M.; Ellis, Richard S.; English, Robin J.; Ferrand, Didier; Ferreira, Décio; Fisher, Charles D.; Golebiowski, Mirek; Gunn, James E.; Hart, Murdock; Heckman, Timothy M.; Ho, Paul T. P.; Hope, Stephen; Hovland, Larry E.; Hsu, Shu-Fu; Hu, Yen-Sang; Huang, Pin Jie; Jaquet, Marc; Karr, Jennifer E.; Kempenaar, Jason G.; King, Matthew E.; Le Fèvre, Olivier; Le Mignant, David; Ling, Hung-Hsu; Loomis, Craig; Lupton, Robert H.; Madec, Fabrice; Mao, Peter; Marrara, Lucas S.; Ménard, Brice; Morantz, Chaz; Murayama, Hitoshi; Murray, Graham J.; de Oliveira, Antonio Cesar; de Oliveira, Claudia M.; de Oliveira, Ligia S.; Orndorff, Joe D.; de Paiva Vilaça, Rodrigo; Partos, Eamon J.; Pascal, Sandrine; Pegot-Ogier, Thomas; Reiley, Daniel J.; Riddle, Reed; Santos, Leandro; dos Santos, Jesulino B.; Schwochert, Mark A.; Seiffert, Michael D.; Smee, Stephen A.; Smith, Roger M.; Steinkraus, Ronald E.; Sodré, Laerte; Spergel, David N.; Surace, Christian; Tresse, Laurence; Vidal, Clément; Vives, Sebastien; Wang, Shiang-Yu; Wen, Chih-Yi; Wu, Amy C.; Wyse, Rosie; Yan, Chi-Hung

    2014-07-01

    The Prime Focus Spectrograph (PFS) is an optical/near-infrared multi-fiber spectrograph with 2394 science fibers, which are distributed in 1.3 degree diameter field of view at Subaru 8.2-meter telescope. The simultaneous wide wavelength coverage from 0.38 μm to 1.26 μm, with the resolving power of 3000, strengthens its ability to target three main survey programs: cosmology, Galactic archaeology, and galaxy/AGN evolution. A medium resolution mode with resolving power of 5000 for 0.71 μm to 0.89 μm also will be available by simply exchanging dispersers. PFS takes the role for the spectroscopic part of the Subaru Measurement of Images and Redshifts (SuMIRe) project, while Hyper Suprime-Cam (HSC) works on the imaging part. HSC's excellent image qualities have proven the high quality of the Wide Field Corrector (WFC), which PFS shares with HSC. The PFS collaboration has succeeded in the project Preliminary Design Review and is now in a phase of subsystem Critical Design Reviews and construction. To transform the telescope plus WFC focal ratio, a 3-mm thick broad-band coated microlens is glued to each fiber tip. The microlenses are molded glass, providing uniform lens dimensions and a variety of refractive-index selection. After successful production of mechanical and optical samples, mass production is now complete. Following careful investigations including Focal Ratio Degradation (FRD) measurements, a higher transmission fiber is selected for the longest part of cable system, while one with a better FRD performance is selected for the fiber-positioner and fiber-slit components, given the more frequent fiber movements and tightly curved structure. Each Fiber positioner consists of two stages of piezo-electric rotary motors. Its engineering model has been produced and tested. After evaluating the statistics of positioning accuracies, collision avoidance software, and interferences (if any) within/between electronics boards, mass production will commence. Fiber

  19. Compact microchannel system

    DOEpatents

    Griffiths, Stewart

    2003-09-30

    The present invention provides compact geometries for the layout of microchannel columns through the use of turns and straight channel segments. These compact geometries permit the use of long separation or reaction columns on a small microchannel substrate or, equivalently, permit columns of a fixed length to occupy a smaller substrate area. The new geometries are based in part on mathematical analyses that provide the minimum turn radius for which column performance in not degraded. In particular, we find that straight channel segments of sufficient length reduce the required minimum turn radius, enabling compact channel layout when turns and straight segments are combined. The compact geometries are obtained by using turns and straight segments in overlapped or nested arrangements to form pleated or coiled columns.

  20. Dark compact planets

    NASA Astrophysics Data System (ADS)

    Tolos, Laura; Schaffner-Bielich, Jürgen

    2015-12-01

    We investigate compact objects formed by dark matter admixed with ordinary matter made of neutron-star matter and white-dwarf material. We consider non-self annihilating dark matter with an equation of state given by an interacting Fermi gas. We find new stable solutions, dark compact planets, with Earth-like masses and radii from a few Km to few hundred Km for weakly interacting dark matter which are stabilized by the mutual presence of dark matter and compact star matter. For the strongly interacting dark matter case, we obtain dark compact planets with Jupiter-like masses and radii of few hundred Km. These objects could be detected by observing exoplanets with unusually small radii. Moreover, we find that the recently observed 2 M⊙ pulsars set limits on the amount of dark matter inside neutron stars which is, at most, 1 0-6 M⊙ .

  1. DYNAMICS IN SUNSPOT UMBRA AS SEEN IN NEW SOLAR TELESCOPE AND INTERFACE REGION IMAGING SPECTROGRAPH DATA

    SciTech Connect

    Yurchyshyn, V.; Abramenko, V.; Kilcik, A.

    2015-01-10

    We analyze sunspot oscillations using Interface Region Imaging Spectrograph (IRIS) slit-jaw and spectral data and narrow-band chromospheric images from the New Solar Telescope (NST) for the main sunspot in NOAA AR 11836. We report that the difference between the shock arrival times as measured by the Mg II k 2796.35 Å and Si IV 1393.76 Å line formation levels changes during the observed period, and peak-to-peak delays may range from 40 s to zero. The intensity of chromospheric shocks also displays long-term (about 20 min) variations. NST's high spatial resolution Hα data allowed us to conclude that, in this sunspot, umbral flashes (UFs) appeared in the form of narrow bright lanes stretched along the light bridges and around clusters of umbral bright points. The time series also suggested that UFs preferred to appear on the sunspot-center side of light bridges, which may indicate the existence of a compact sub-photospheric driver of sunspot oscillations. The sunspot's umbra as seen in the IRIS chromospheric and transition region data appears bright above the locations of light bridges and the areas where the dark umbra is dotted with clusters of umbral dots. Co-spatial and co-temporal data from the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory showed that the same locations were associated with bright footpoints of coronal loops suggesting that the light bridges may play an important role in heating the coronal sunspot loops. Finally, the power spectra analysis showed that the intensity of chromospheric and transition region oscillations significantly vary across the umbra and with height, suggesting that umbral non-uniformities and the structure of sunspot magnetic fields may play a role in wave propagation and heating of umbral loops.

  2. Dynamics in Sunspot Umbra as Seen in New Solar Telescope and Interface Region Imaging Spectrograph Data

    NASA Astrophysics Data System (ADS)

    Yurchyshyn, V.; Abramenko, V.; Kilcik, A.

    2015-01-01

    We analyze sunspot oscillations using Interface Region Imaging Spectrograph (IRIS) slit-jaw and spectral data and narrow-band chromospheric images from the New Solar Telescope (NST) for the main sunspot in NOAA AR 11836. We report that the difference between the shock arrival times as measured by the Mg II k 2796.35 Å and Si IV 1393.76 Å line formation levels changes during the observed period, and peak-to-peak delays may range from 40 s to zero. The intensity of chromospheric shocks also displays long-term (about 20 min) variations. NST's high spatial resolution Hα data allowed us to conclude that, in this sunspot, umbral flashes (UFs) appeared in the form of narrow bright lanes stretched along the light bridges and around clusters of umbral bright points. The time series also suggested that UFs preferred to appear on the sunspot-center side of light bridges, which may indicate the existence of a compact sub-photospheric driver of sunspot oscillations. The sunspot's umbra as seen in the IRIS chromospheric and transition region data appears bright above the locations of light bridges and the areas where the dark umbra is dotted with clusters of umbral dots. Co-spatial and co-temporal data from the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory showed that the same locations were associated with bright footpoints of coronal loops suggesting that the light bridges may play an important role in heating the coronal sunspot loops. Finally, the power spectra analysis showed that the intensity of chromospheric and transition region oscillations significantly vary across the umbra and with height, suggesting that umbral non-uniformities and the structure of sunspot magnetic fields may play a role in wave propagation and heating of umbral loops.

  3. Compact baby Skyrmions

    SciTech Connect

    Adam, C.; Klimas, P.; Sanchez-Guillen, J.; Wereszczynski, A.

    2009-11-15

    For the baby Skyrme model with a specific potential, compacton solutions, i.e., configurations with a compact support and parabolic approach to the vacuum, are derived. Specifically, in the nontopological sector, we find spinning Q-balls and Q-shells, as well as peakons. Moreover, we obtain compact baby skyrmions with nontrivial topological charge. All these solutions may form stable multisoliton configurations provided they are sufficiently separated.

  4. Optical Spectrum of the Compact Planetary Nebula IC 5117

    NASA Technical Reports Server (NTRS)

    Hyung, Siek; Aller, Lawrence H.; Feibelman, Walter A.; Lee, Seong-Jae; Fisher, Richard R. (Technical Monitor)

    2001-01-01

    High resolution spectroscopic data of the very compact planetary nebula IC 5117 are obtained in the optical wavelengths, 3700A - 10050A, with the Hamilton Echelle Spectrograph at Lick Observatory, and which have been analyzed along with the International Ultraviolet Explorer (IUE) UV archive data. Although a diagnostic diagram shows significant density and temperature fluctuations, our analysis indicates that the nebular gas may be represented by a homogeneous shell of extremely high density gas, N(sub epsilon) approx. 90 000 /cu cm. The average electron temperatures, e.g. indicated by the [OIII] diagnostics, are around 12 000 K. We construct a photoionization model to represent most of the observed line intensities, and the physical condition of this compact nebulosity. Based on the semi-empirical ionization correction approach, and model indications, we derived the elemental abundances: He, C, N, O, Ne, and Ar appear to be normal or marginally depleted compared to the average planetary nebula, while the remaining elements, S, Cl, and K appear to be enhanced. IC 5117 is perhaps a very young compact planetary nebula, slightly more evolved than the other well-known compact planetary nebula IC 4997. The central stellar temperature is likely to be around 120 000 K, evolved from a C-rich AGB progenitor.

  5. Test observations of the Kyoto Tridimensional Spectrograph II at the University of Hawaii 88-in and Subaru Telescopes

    NASA Astrophysics Data System (ADS)

    Sugai, Hajime; Hattori, Takashi; Kawai, Atsushi; Ozaki, Shinobu; Kosugi, George; Ohtani, Hiroshi; Hayashi, Tadashi; Ishigaki, Tsuyoshi; Ishii, Motomi; Sasaki, Minoru; Shimono, Atsushi; Okita, Yoshiko; Sudo, Jun; Takeyama, Norihide

    2004-09-01

    In order to investigate the physical conditions of ionized gas in galaxies, as well as its kinematics, we have developed the Kyoto tridimensional spectrograph II (3DII). It is a multi-mode instrument designed for Cassegrain focus, including integral field spectrograph (IFS) and Fabry-Perot imager modes. We have designed it compact so that we can mount it at 2-m class telescopes as well as at 8-m Subaru telescope. We have succeeded in test observations of the 3DII. In the IFS mode the spatial resolution of ~ 0".5 and 0".4 was obtained in 30-minute exposures at University of Hawaii 88-inch (UH88) and Subaru, respectively, in relatively good weather conditions. Each of 37 × 37 microlenses subtends ~ 0".1 in Subaru's case. This samples well the image size. A wider field of view is emphasized in the case of UH88. Because our micropupil spectroscopy is free from a slit effect, we have reached the accuracy of an order of one tenth of a pixel for deriving velocity fields in terms of velocity center while the full width at half maximum of the instrumental profile corresponds to two pixels. At Subaru we have used a container designed in a collaboration with National Astronomical Observatory, Japan: it fits with a robotic instrument exchanger. The containerincludes two heat exchangers to keep its surface cool and void degrading the image quality. We have established effective observational equences by realizing a software interface with Subaru operating system. ome results from target observations are shown.

  6. Construction and status of the CHARIS high contrast imaging spectrograph

    NASA Astrophysics Data System (ADS)

    Groff, Tyler D.; Kasdin, N. J.; Limbach, Mary A.; Galvin, Michael; Carr, Michael A.; Knapp, Gillian; Brandt, Timothy; Loomis, Craig; Jarosik, Norm; Mede, Kyle; McElwain, Michael W.; Janson, Markus; Guyon, Olivier; Jovanovic, Nemanja; Takato, Naruhisa; Martinache, Frantz; Hayashi, Masahiko

    2014-07-01

    Princeton University is building the Coronagraphic High Angular Resolution Imaging Spectrograph (CHARIS), an integral field spectrograph (IFS) for the Subaru telescope. CHARIS is funded by the National Astronomical Observatory of Japan and is designed to take high contrast spectra of brown dwarfs and hot Jovian planets in the coronagraphic image provided by the Coronagraphic Extreme Adaptive Optics (SCExAO) and the AO188 adaptive optics systems. The project is now in the build and test phase at Princeton University. Once laboratory testing has been completed CHARIS will be integrated with SCExAO and AO188 in the winter of 2016. CHARIS has a high-resolution characterization mode in J, H, and K bands. The average spectral resolution in J, H, and K bands are R82, R68, and R82 respectively, the uniformity of which is a direct result of a new high index material, L-BBH2. CHARIS also has a second low-resolution imaging mode that spans J,H, and K bands with an average spectral resolution of R19, a feature unique to this instrument. The field of view in both imaging modes is 2.07x2.07 arcseconds. SCExAO+CHARIS will detect objects five orders of magnitude dimmer than their parent star down to an 80 milliarcsecond inner working angle. The primary challenge with exoplanet imaging is the presence of quasi-static speckles in the coronagraphic image. SCExAO has a wavefront control system to suppress these speckles and CHARIS will address their impact on spectral crosstalk through hardware design, which drives its optical and mechanical design. CHARIS constrains crosstalk to be below 1% for an adjacent source that is a full order of magnitude brighter than the neighboring spectra. Since CHARIS is on the Nasmyth platform, the optical alignment between the lenslet array and prism is highly stable. This improves the stability of the spectra and their orientation on the detector and results in greater stability in the wavelength solution for the data pipeline. This means less

  7. Design and realization of the real-time spectrograph controller for LAMOST based on FPGA

    NASA Astrophysics Data System (ADS)

    Wang, Jianing; Wu, Liyan; Zeng, Yizhong; Dai, Songxin; Hu, Zhongwen; Zhu, Yongtian; Wang, Lei; Wu, Zhen; Chen, Yi

    2008-08-01

    A large Schmitt reflector telescope, Large Sky Area Multi-Object Fiber Spectroscopic Telescope(LAMOST), is being built in China, which has effective aperture of 4 meters and can observe the spectra of as many as 4000 objects simultaneously. To fit such a large amount of observational objects, the dispersion part is composed of a set of 16 multipurpose fiber-fed double-beam Schmidt spectrographs, of which each has about ten of moveable components realtimely accommodated and manipulated by a controller. An industrial Ethernet network connects those 16 spectrograph controllers. The light from stars is fed to the entrance slits of the spectrographs with optical fibers. In this paper, we mainly introduce the design and realization of our real-time controller for the spectrograph, our design using the technique of System On Programmable Chip (SOPC) based on Field Programmable Gate Array (FPGA) and then realizing the control of the spectrographs through NIOSII Soft Core Embedded Processor. We seal the stepper motor controller as intellectual property (IP) cores and reuse it, greatly simplifying the design process and then shortening the development time. Under the embedded operating system μC/OS-II, a multi-tasks control program has been well written to realize the real-time control of the moveable parts of the spectrographs. At present, a number of such controllers have been applied in the spectrograph of LAMOST.

  8. PRAXIS: a low background NIR spectrograph for fibre Bragg grating OH suppression

    NASA Astrophysics Data System (ADS)

    Horton, Anthony; Ellis, Simon; Lawrence, Jon; Bland-Hawthorn, Joss

    2012-09-01

    Fibre Bragg grating (FBG) OH suppression is capable of greatly reducing the bright sky background seen by near infrared spectrographs. By filtering out the airglow emission lines at high resolution before the light enters the spectrograph this technique prevents scattering from the emission lines into interline regions, thereby reducing the background at all wavelengths. In order to take full advantage of this sky background reduction the spectrograph must have very low instrumental backgrounds so that it remains sky noise limited. Both simulations and real world experience with the prototype GNOSIS system show that existing spectrographs, designed for higher sky background levels, will be unable to fully exploit the sky background reduction. We therefore propose PRAXIS, a spectrograph optimised specifically for this purpose. The PRAXIS concept is a fibre fed, fully cryogenic, fixed format spectrograph for the J and H-bands. Dark current will be minimised by using the best of the latest generation of NIR detectors while thermal backgrounds will be reduced by the use of a cryogenic fibre slit. Optimised spectral formats and the use of high throughput volume phase holographic gratings will further enhance sensitivity. Our proposal is for a modular system, incorporating exchangeable fore-optics units, integral field units and OH suppression units, to allow PRAXIS to operate as a visitor instrument on any large telescope and enable new developments in FBG OH suppression to be incorporated as they become available. As a high performance fibre fed spectrograph PRAXIS could also serve as a testbed for other astrophotonic technologies.

  9. Slit Function Measurement of An Imaging Spectrograph Using Fourier Transform Techniques

    NASA Technical Reports Server (NTRS)

    Park, Hongwoo; Swimyard, Bruce; Jakobsen, Peter; Moseley, Harvey; Greenhouse, Matthew

    2004-01-01

    Knowledge of a spectrograph slit function is necessary to interpret the unresolved lines in an observed spectrum. A theoretical slit function can be calculated from the sizes of the entrance slit, the detector aperture when it functions as an exit slit, the dispersion characteristic of the disperser, and the point spread function of the spectrograph. A measured slit function is preferred to the theoretical one for the correct interpretation of the spectral data. In a scanning spectrometer with a single exit slit, the slit function is easily measured. In a fixed grating/or disperser spectrograph, illuminating the entrance slit with a near monochromatic light from a pre-monochrmator or a tunable laser and varying the wavelength of the incident light can measure the slit function. Even though the latter technique had been used successfully for the slit function measurements, it had been very laborious and it would be prohibitive to an imaging spectrograph or a multi-object spectrograph that has a large field of view. We explore an alternative technique that is manageable for the measurements. In the proposed technique, the imaging spectrograph is used as a detector of a Fourier transform spectrometer. This method can be applied not only to an IR spectrograph but also has a potential to a visible/UV spectrograph including a wedge filter spectrograph. This technique will require a blackbody source of known temperature and a bolometer to characterize the interferometer part of the Fourier Transform spectrometer. This pa?er will describe the alternative slit function measurement technique using a Fourier transform spectrometer.

  10. Spectrographic Analysis of Carrion Crow Calls and Their Detection

    NASA Astrophysics Data System (ADS)

    Shibuya, Hisashi; Yokota, Yasunari

    In recent years, damage to agricultural products, livestock, and power transmission systems by crows is regarded as a serious problem; countermeasures against crow damage are urgently necessary. This paper proposed a method for detecting crow calls in various environmental sounds. If detection and discernment of crow calls were possible, various actions could be undertaken to prevent the damage. Wildlife call detection, not only that for crows, should be executed in extremely noisy environments. We then introduced both a spectrograph estimation technique with AR modeling in which AR coefficients are temporally smoothed and interpolated and a background noise elimination technique to obtain higher-quality crow call templates. The input sounds are compared with these templates by DP matching in the metric vector space of a logarithmic cepstrum. Every input sound whose minimal distance to the template database is less than the specified threshold value is detected as a crow call. The maximal detection performance can be obtained when five call templates in the template database are utilized; the implication is that carrion crows have five distinguishable call patterns. It is shown that the proposed method achieves 95% detection rate when 1.66% misdetection rate is allowed.

  11. Goddard High Resolution Spectrograph SV/GTO Project

    NASA Technical Reports Server (NTRS)

    Ebbets, Dennis

    1999-01-01

    Contract number NAS5-30433, known at Ball Aerospace as the GHRS SV/GTO project, supported our participation in the post-launch activities of the Goddard High Resolution Spectrograph aboard the Hubble Space Telescope. The period of performance was December 1988 through December 1998. The contract supported the involvement of Dr Dennis Ebbets in the work of the GHRS Investigation Definition Team, and several of the Ball people in the documentation and publication of results. Three main categories of tasks were covered by this contract; in-orbit calibration of the GHRS, guaranteed time observations, and education and public outreach. The nature and accomplishments of these tasks are described in the report. This summary makes many references to publications in the scientific and technical literature. Appendix A is extracted from a complete bibliography, and lists those papers that are directly related to work performed under this GHRS contract. The tasks related to the in-orbit calibration of the GHRS were by far the largest responsibility during the first six years of the project. During this period Dr. Ebbets was responsible for the definition of calibration requirements, design of experiments, preparation of observing proposals, tracking their implementation and execution, and coordinating the analysis and publication of the results. Prior to the launch of HST in 1990 the observing proposals were developed in cooperation with the scientists on the GHRS DDT, engineers at Ball Aerospace, the operations staff at the STScI, and project coordinators at GSFC.

  12. The Saturn System as Observed by Cassini's Ultraviolet Imaging Spectrograph

    NASA Technical Reports Server (NTRS)

    Esposito, L. W.; Hansen, C. J.; Colwell, J.; Hendrix, A. R.; McClintock, W. E.; Shemansky, D. E.

    2005-01-01

    The Cassini Ultraviolet Imaging Spectrograph (UVIS) has major new findings in all aspects of Saturn science: Saturn, its rings, Titan and the icy satellites, and the Saturn magnetosphere. Dynamic interactions between neutrals, ions, rings, moons and meteoroids produce a highly structured and time variable Saturn system. Highlights and outstanding new results will be reported, focusing on Saturn s moons and their interaction with their environment. The UVIS is one of Cassini s suite of remote sensing instruments. The UVIS instrument includes channels for extreme UV (55 to 110 nm) and far UV (110 to 190 nm) spectroscopic imaging, high speed photometry of stellar occultations, solar EUV occultation, and a hydrogen/deuterium absorption cell. UVIS has detected products of water dissociation, neutral oxygen and OH, which dominate the Saturn inner magnetosphere, in contrast to Jupiter, and H fills the entire magnetosphere apparently extending through the magnetopause at far greater density than the ion population. The O and OH and a fraction of the H are probably the products of water physical chemistry, and derived ultimately from water ice. Observed fluctuations indicate close interactions with plasma sources. Sputtering from the satellites water ice surfaces is insufficient to supply the observed mass. Stochastic events in the E ring may be the ultimate source.

  13. Qsys NOC-based MPSOC design for LAMOST Spectrographs

    NASA Astrophysics Data System (ADS)

    Han, Zhongyi; Wang, Jianing; Zeng, Yizhong

    2012-09-01

    At present, FPGA-based SOPC was used to design the China's LAMOST telescope spectrograph control system. But with the increase of the controlled objects and requirement of telescope’s accuracy, the problems like system performance, I/O source shortage, real-time multi-task processing, Fmax, Logic Element (LE) Usage have to be solved immediately. The combination of multi-processor (NIOS II) method and NOC technology can meet this requirement effectively. This article mainly introduced how to realize the NOC-based MPSOC in the Altera’s Cyclone III FPGA experimental board by Qsys tool. According to the function of task, the system was divided into several subsystems which also include two NIOS II CPU subsystems (implement the control strategies and remote update tasks separately). These different subsystems are interconnected by NOC hierarchical interconnection idea. The results illustrate that this solution can improve system performance, double the Fmax, decrease LE usage, and save the maintenance cost compared with the previous SOPC-based approach. The motor control system designed by this approach also can be applied to other astronomy equipments and industrial control fields.

  14. Performance of the Space Telescope Imaging Spectrograph after SM4

    NASA Technical Reports Server (NTRS)

    Proffitt, Charles R.; Alosi, A.; Bohlin, R. C.; Bostroen, K. A.; Cox, C. R.; Diaz, R. I.; Dixon, W. V.; Goudfrooij, P.; Hodge, P.; Kaiser, M. E.; Lallo, M. D.; Lennon, D.; Niemi, S.; Pascucci, I.; Smith, E.; Wolfe, M. A.; York, B.; Zheng. W.; Gull, T. R.; Lindler, D. J.; Woodgate, B. E.

    2010-01-01

    On May 17, 2009, during the fourth EVA of SM4, astronauts Michael Good and Mike Massimino replaced the failed LVPS-2 circuit board on the Space Telescope Imaging Spectrograph (STIS), restoring this HST instrument to operation after a nearly 6 year hiatus. STIS after this 2009 repair operates in much the same way as it did during the 2001-2004 period of operations with the Side-2 electronics. Internal and external alignments of the instrument are similar to what they had been in 2004, and most changes in performance are modest. The STIS CCD detector continued to experience radiation damage during the hiatus in operations, leading to decreased charge transfer efficiency (CTE) and an increased number of hot pixels. The sensitivities for most modes are surprisingly close to what was expected from simple extrapolation of the 2003-2004 trends, although the echelle modes show somewhat more complex behavior. The biggest surprise was that the dark count rate for the NUV MAMA detector after SM4 has been much larger than had been expected; it is currently about 2.5 times bigger than it was in 2004 and is only slowly decreasing. We discuss how these changes will affect science with STIS now and in the future.

  15. Space Telescope Imaging Spectrograph Co-Investigator Support

    NASA Technical Reports Server (NTRS)

    Weistrop, Donna

    2003-01-01

    The purpose of this contract has been to support investigation of astronomical problems primarily using data from the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope (HST). As a Co-investigator on STIS, I participated in several projects, which will be described below. The research resulted in 19 papers in refereed journals, 8 papers published in conference proceedings, and 27 papers presented at meetings. There are still at least four papers submitted or in press, as well as some additional research yet to be written up for publication. The research has also produced one master's thesis and two PhD dissertations currently underway, with one to be completed Spring 2003. Undergraduates have participated in the analysis of supporting observations. One student has published some of his results in a web- based refereed publication for undergraduate research (www.jyi.org). I have given several talks to the general public describing results from the HST as well as the results of my research. I have been named the UNLV Regents' Outstanding Faculty Member for 1995 and received the 2002 College of Science Distinguished Researcher's Award as a result of these activities.

  16. CASSIS: The Cornell Atlas of Spitzer/Infrared Spectrograph Sources

    NASA Astrophysics Data System (ADS)

    Lebouteiller, V.; Barry, D. J.; Spoon, H. W. W.; Bernard-Salas, J.; Sloan, G. C.; Houck, J. R.; Weedman, D. W.

    2011-09-01

    We present the spectral atlas of sources observed in low resolution with the Infrared Spectrograph on board the Spitzer Space Telescope. More than 11,000 distinct sources were extracted using a dedicated algorithm based on the SMART software with an optimal extraction (AdOpt package). These correspond to all 13,000 low-resolution observations of fixed objects (both single source and cluster observations). The pipeline includes image cleaning, individual exposure combination, and background subtraction. Particular attention is given to bad pixel and outlier rejection at the image and spectra levels. Most sources are spatially unresolved so that optimal extraction reaches the highest possible signal-to-noise ratio. For all sources, an alternative extraction is also provided that accounts for all of the source flux within the aperture. CASSIS provides publishable quality spectra through an online database together with several important diagnostics, such as the source spatial extent and a quantitative measure of detection level. Ancillary data such as available spectroscopic redshifts are also provided. The database interface will eventually provide various ways to interact with the spectra, such as on-the-fly measurements of spectral features or comparisons among spectra.

  17. The Miniature X-ray Spectrograph (MiXS)

    NASA Astrophysics Data System (ADS)

    Martinez Oliveros, Juan Carlos; Glesener, Lindsay; Saint Hilaire, Pascal; Sundkvist, David; Hurford, Gordon; Bain, Hazel; Bale, Stuart D.; Krucker, Sam

    2015-04-01

    The Miniature X-ray Spectrograph (MiXS) is an innovative, small, and fully functional solar X-ray observatory concept designed to fit within a 6U CubeSat platform. MiXS will provide the community with X-ray spectroscopy up to 100 keV of solar flares at a small fraction of the cost of a conventional mission. It includes layered Si/CdTe detectors, providing routine observations of both soft and hard X-ray emission with low background. If selected for funding, MiXS will provide hard X-ray (HXR) spectroscopy throughout the declining phase of this solar cycle allowing continuous solar observations while new generation HXR instrumentation put in orbit. MiXS is the first stage of a much ambitious cube design the Miniature Xray Imager (MiXI), which can provide to the community X-ray imaging up to 40 - 50 keV. In the next solar cycle, coordinated observations between Solar Orbiter’s STIX instrument and future MiXS or MiXI iterations will enable solar flare observation from two vantage points, while new observatories will be commissioned. This will provide new insight into the directivity of flare HXR emission and will allow detailed study of both coronal and footpoint sources within the same flare. These results may have profound implications for theories of flare acceleration processes. We describe here the MiXS concept and its usefulness to the solar and heliophysics communities.

  18. Successful "First Light" for VLT High-Resolution Spectrograph

    NASA Astrophysics Data System (ADS)

    1999-10-01

    Great Research Prospects with UVES at KUEYEN A major new astronomical instrument for the ESO Very Large Telescope at Paranal (Chile), the UVES high-resolution spectrograph, has just made its first observations of astronomical objects. The astronomers are delighted with the quality of the spectra obtained at this moment of "First Light". Although much fine-tuning still has to be done, this early success promises well for new and exciting science projects with this large European research facility. Astronomical instruments at VLT KUEYEN The second VLT 8.2-m Unit Telescope, KUEYEN ("The Moon" in the Mapuche language), is in the process of being tuned to perfection before it will be "handed" over to the astronomers on April 1, 2000. The testing of the new giant telescope has been successfully completed. The latest pointing tests were very positive and, from real performance measurements covering the entire operating range of the telescope, the overall accuracy on the sky was found to be 0.85 arcsec (the RMS-value). This is an excellent result for any telescope and implies that KUEYEN (as is already the case for ANTU) will be able to acquire its future target objects securely and efficiently, thus saving precious observing time. This work has paved the way for the installation of large astronomical instruments at its three focal positions, all prototype facilities that are capable of catching the light from even very faint and distant celestial objects. The three instruments at KUEYEN are referred to by their acronyms UVES , FORS2 and FLAMES. They are all dedicated to the investigation of the spectroscopic properties of faint stars and galaxies in the Universe. The UVES instrument The first to be installed is the Ultraviolet Visual Echelle Spectrograph (UVES) that was built by ESO, with the collaboration of the Trieste Observatory (Italy) for the control software. Complete tests of its optical and mechanical components, as well as of its CCD detectors and of the complex

  19. Performance of the Space Telescope Imaging Spectrograph after

    NASA Astrophysics Data System (ADS)

    Proffitt, Charles R.; Aloisi, A.; Bohlin, C.; Bostroem, K. A.; Cox, C. R.; Diaz, R. I.; Dixon, W. V.; Goudfrooij, P.; Hodge, P.; Kaiser, M. E. Lallo, M. D.; Lennon, D.; Niemi, S.; Osten, R. A.; Pascucci, I.; Smith, E.; Wolfe, M. A.; York, B.; Zheng, W.; Gull, T. R.; Lindler, D. J.; Woodgate, B. E.

    2010-07-01

    On May 17, 2009, during the fourth EVA of SM4, astronauts Michael Good and Mike Massimino replaced the failed LVPS-2 circuit board on the Space Telescope Imaging Spectrograph (STIS), restoring this HST instrument to operation after a nearly 6 year hiatus. STIS after this 2009 repair operates in much the same way as it did during the 2001-2004 period of operations with the Side-2 electronics. Internal and external alignments of the instrument are similar to what they had been in 2004, and most changes in performance are modest. The STIS CCD detector continued to experience radiation damage during the hiatus in operations, leading to decreased charge transfer efficiency (CTE) and an increased number of hot pixels. The sensitivities for most modes are surprisingly close to what was expected from simple extrapolation of the 2003-2004 trends, although the echelle modes show somewhat more complex behavior. The biggest surprise was that the dark count rate for the NUV MAMA detector after SM4 has been much larger than had been expected; it is currently about 2.5 times bigger than it was in 2004 and is only slowly decreasing. We discuss how these changes will affect science with STIS now and in the future.

  20. CASSIS: THE CORNELL ATLAS OF SPITZER/INFRARED SPECTROGRAPH SOURCES

    SciTech Connect

    Lebouteiller, V.; Barry, D. J.; Spoon, H. W. W.; Bernard-Salas, J.; Sloan, G. C.; Houck, J. R.; Weedman, D. W.

    2011-09-01

    We present the spectral atlas of sources observed in low resolution with the Infrared Spectrograph on board the Spitzer Space Telescope. More than 11,000 distinct sources were extracted using a dedicated algorithm based on the SMART software with an optimal extraction (AdOpt package). These correspond to all 13,000 low-resolution observations of fixed objects (both single source and cluster observations). The pipeline includes image cleaning, individual exposure combination, and background subtraction. Particular attention is given to bad pixel and outlier rejection at the image and spectra levels. Most sources are spatially unresolved so that optimal extraction reaches the highest possible signal-to-noise ratio. For all sources, an alternative extraction is also provided that accounts for all of the source flux within the aperture. CASSIS provides publishable quality spectra through an online database together with several important diagnostics, such as the source spatial extent and a quantitative measure of detection level. Ancillary data such as available spectroscopic redshifts are also provided. The database interface will eventually provide various ways to interact with the spectra, such as on-the-fly measurements of spectral features or comparisons among spectra.

  1. Interface Region Imaging Spectrograph (IRIS) entrance aperture design

    NASA Astrophysics Data System (ADS)

    Cheimets, P.; Park, S.; Bergner, H.; Chou, C.; Gates, R.; Honsa, M.; Podgorski, W.; Yanari, C.

    2014-07-01

    The Interface Region Imaging Spectrograph (IRIS) is a complementary follow-on to Solar Dynamics Observatory Atmospheric Imaging Assembly (SDO-AIA) and funded as a member of the NASA SMEX program. This paper presents the thermal design of the IRIS telescope front end, with a focus on the IRIS door and entrance aperture assembly. The challenge of the IRIS entrance aperture, including the door design, was to manage the solar flux, both before and after the door was opened. This is especially a problem with instruments that are permanently pointed directly at the sun. Though there is an array of effective flux-rejecting coatings, they are expensive, hard to apply, harder to measure, delicate, prone to unpredictable performance decay with exposure, and very often a source of contamination. This paper presents a thermal control and protection method based on robust, inexpensive coatings and materials, combined to produce high thermal and structural isolation. The end result is a first line of thermal protection whose performance is easy to predict and well isolated from the instrument it is protecting.

  2. Space Telescope Imaging Spectrograph Coronagraphic Observations of β Pictoris

    NASA Astrophysics Data System (ADS)

    Heap, Sara R.; Lindler, Don J.; Lanz, Thierry M.; Cornett, Robert H.; Hubeny, Ivan; Maran, S. P.; Woodgate, Bruce

    2000-08-01

    We present new coronagraphic images of β Pictoris obtained with the Space Telescope Imaging Spectrograph (STIS) in 1997 September. The high-resolution images (0.1") clearly detect the circumstellar disk as close to the star as 0.75", corresponding to a projected radius of 15 AU. The images define the warp in the disk with greater precision and at closer radii to β Pic than do previous observations. They show that the warp can be modeled by the projection of two components: the main disk and a fainter component, which is inclined to the main component by 4°-5° and extends only as far as ~4" from the star. We interpret the main component as arising primarily in the outer disk and the tilted component as defining the inner region of the disk. The observed properties of the warped inner disk are inconsistent with a driving force from stellar radiation. However, warping induced by the gravitational potential of one or more planets is consistent with the data. Using models of planet-warped disks constructed by Larwood & Papaloizou, we derive possible masses of the perturbing object. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

  3. Conceptual design of the MOBIE imaging spectrograph for TMT

    NASA Astrophysics Data System (ADS)

    Bigelow, Bruce C.; Radovan, Matthew V.; Bernstein, Rebecca A.; Onaka, Peter M.; Yamada, Hubert; Isani, Sidik; Miyazaki, Satoshi; Ozaki, Shinobu

    2014-08-01

    The Multi-Object Broadband Imaging Echellette (MOBIE) is the seeing-limited, visible-wavelength imaging multiobject spectrograph (MOS) planned for first-light use on the Thirty Meter Telescope (TMT). The MOBIE project to date has been a collaboration lead by UC Observatories (CA), and including the UH Institute for Astronomy (HI), and the NAOJ (Tokyo, Japan). The current MOBIE optical design provides two color channels, spanning the 310-550nm and 550-1000nm passbands, and a combination of reflection gratings, prisms, and mirrors to enable direct imaging and three spectroscopic modes with resolutions (λ/triangle λ) of roughly 1000, 3000, and 8000 in both color channels, across a field of view that ranges from roughly 8x3 arcmin to 3x3 arcmin, depending on resolution mode. The conceptual design phase for the MOBIE instrument has been underway since 2008 and is expected to end in 2015. We report here on developments since 2010, including assembly of the current project team, instrument and camera optical designs, instrument control systems, atmospheric dispersion corrector, slit-mask exchange systems, collimator, dichroic and fold optics, dispersing and cross-dispersing optics, refracting cameras, shutters, filter exchange systems, science detector systems, and instrument structures.

  4. Exposure time calculator for Immersion Grating Infrared Spectrograph: IGRINS

    NASA Astrophysics Data System (ADS)

    Le, Huynh Anh N.; Pak, Soojong; Jaffe, Daniel T.; Kaplan, Kyle; Lee, Jae-Joon; Im, Myungshin; Seifahrt, Andreas

    2015-06-01

    We present an exposure-time calculator (ETC) for the Immersion Grating Infrared Spectrograph (IGRINS). The signal and noise values are calculated by taking into account the telluric background emission and absorption, the emission and transmission of the telescope and instrument optics, and the dark current and read noise of the infrared detector arrays. For the atmospheric transmission, we apply models based on the amount of precipitable water vapor along the line of sight to the target. The ETC produces the expected signal-to-noise ratio (S/N) for each resolution element, given the exposure-time and number of exposures. In this paper, we compare the simulated continuum S/N for the early-type star HD 124683 and the late-type star GSS 32, and the simulated emission line S/N for the H2 rovibrational transitions from the Iris Nebula NGC 7023 with the observed IGRINS spectra. The simulated S/N from the ETC is overestimated by 40-50% for the sample continuum targets.

  5. IONIZED OUTFLOWS FROM COMPACT STEEP SPECTRUM SOURCES

    SciTech Connect

    Shih, Hsin-Yi; Stockton, Alan; Kewley, Lisa E-mail: stockton@ifa.hawaii.edu

    2013-08-01

    Massive outflows are known to exist, in the form of extended emission-line regions (EELRs), around about one-third of powerful FR II radio sources. We investigate the origin of these EELRs by studying the emission-line regions around compact-steep-spectrum (CSS) radio galaxies that are younger (10{sup 3}-10{sup 5} yr old) versions of the FR II radio galaxies. We have searched for and analyzed the emission-line regions around 11 CSS sources by taking integral field spectra using Gemini Multi-Object Spectrograph on Gemini North. We fit the [O III] {lambda}5007 line and present the velocity maps for each detected emission-line region. We find, in most cases, that the emission-line regions have multi-component velocity structures with different velocity dispersions and/or flux distributions for each component. The velocity gradients of the emission-line gas are mostly well aligned with the radio axis, suggesting a direct causal link between the outflowing gas and the radio jets. The complex velocity structure may be a result of different driving mechanisms related to the onset of the radio jets. We also present the results from the line-ratio diagnostics we used to analyze the ionization mechanism of the extended gas, which supports the scenario where the emission-line regions are ionized by a combination of active galactic nucleus radiation and shock excitation.

  6. The development of ground-based infrared multi-object spectrograph based on the microshutter array

    NASA Astrophysics Data System (ADS)

    Moon, Dae-Sik; Sivanandam, Suresh; Kutyrev, Alexander S.; Moseley, Samuel H.; Graham, James R.; Roy, Aishwarya

    2014-07-01

    We report on our development of a near-infrared multi-object spectrograph for ground-based applications using the micro-shutter array, which was originally developed for the Near Infrared Spectrograph of the James Webb Space Telescope. The micro-shutter array in this case acts as a source selector at a reimaged telescope focal plane. The developed spectrograph will be implemented either with ground-layer adaptive optics system or multi-conjugate adaptive optics system on a large telescope. This will enable for the first time fully reconfigurable infrared multi-object spectroscopy with adaptive optics systems. We envision studying diverse astronomical objects with our spectrograph, including high-redshift galaxies, galaxy clusters and super star clusters.

  7. A Spectrographic Investigation of Consonant-Vowel Transitions in the Speech of Deaf Adults

    ERIC Educational Resources Information Center

    Rothman, Howard B.

    1976-01-01

    A spectrographic investigation was carried out on the speech of normal hearing and deaf speakers; the research attempted to answer questions concerning formant transitions, coarticulation and neutralization of vowels in the speech of the deaf adults. (Author/RM)

  8. SPIRAL Phase A: A Prototype Integral Field Spectrograph for the Anglo-AustralianTelescope

    NASA Astrophysics Data System (ADS)

    Kenworthy, Matthew A.; Parry, Ian R.; Taylor, Keith

    2001-02-01

    We present details of a prototype fiber feed for use on the Anglo-Australian Telescope (AAT) that uses a dedicated fiber-fed medium/high-resolution (R~=10,000) visible-band spectrograph to give integral field spectroscopy (IFS) of an extended object. A focal reducer couples light from the telescope to the close-packed lenslet array and fiber feed, allowing the spectrograph be used on other telescopes with the change of a single lens. By considering the properties of the fibers in the design of the spectrograph, an efficient design can be realized; we present the first scientific results of a prototype spectrograph using a fiber feed with 37 spatial elements, namely, the detection of lithium confirming a brown dwarf candidate and IFS of the supernova remnant SN 1987A.

  9. Adjustment of a tower solar telescope and spectrograph: A method manual

    NASA Astrophysics Data System (ADS)

    Stepanian, N. N.; Sunitsa, G. A.; Malashchuk, V. M.

    2014-06-01

    Questions of the mounting and adjustment of a tower solar telescope are considered through the example of the TST-2 telescope of the Crimean Astrophysical Observatory Scientific Research Institute. The authors describe the optical circuits of the telescope and spectrograph and list the basic requirements for the mutual arrangement of individual components of the telescope. Simple methods for adjusting elements of the telescope and spectrograph are described.

  10. An experimental study of the luminosity of an MFC-MAES-based digital spectrograph

    NASA Astrophysics Data System (ADS)

    Drobyshev, A. I.; Savinov, S. S.

    2016-02-01

    We experimentally investigated the dependence of luminosity of a digital spectrograph for the line spectrum on the input slit width in the range 5-100 μm for different ways of measuring the spectral line image intensity. Based on the results obtained, we showed that the spectrograph luminosity can be increased by more than an order of magnitude via a multiple increase in the input slit width over the normal one with a conserved minimum instrumental response function width.

  11. Limestone compaction: an enigma

    USGS Publications Warehouse

    Shinn, Eugene A.; Halley, Robert B.; Hudson, J. Harold; Lidz, Barbara H.

    1977-01-01

    Compression of an undisturbed carbonate sediment core under a pressure of 556 kg/cm2 produced a “rock” with sedimentary structures similar to typical ancient fine-grained limestones. Surprisingly, shells, foraminifera, and other fossils were not noticeably crushed, which indicates that absence of crushed fossils in ancient limestones can no longer be considered evidence that limestones do not compact.

  12. Compact optical transconductance varistor

    SciTech Connect

    Sampayan, Stephen

    2015-09-22

    A compact radiation-modulated transconductance varistor device having both a radiation source and a photoconductive wide bandgap semiconductor material (PWBSM) integrally formed on a substrate so that a single interface is formed between the radiation source and PWBSM for transmitting PWBSM activation radiation directly from the radiation source to the PWBSM.

  13. COMPACT SCHOOL AND $$ SAVINGS.

    ERIC Educational Resources Information Center

    BAIR, W.G.

    A REVIEW OF THE CRITERIA FOR CONSIDERING THE USE OF A TOTAL ENERGY SYSTEM WITHIN A SCHOOL BUILDING STATES THE WINDOWLESS, COMPACT SCHOOL OFFERS MORE EFFICIENT SPACE UTILIZATION WITH LESS AREA REQUIRED FOR GIVEN STUDENT POPULATION AND LOWER OPERATION COSTS. THE AUTHOR RECOMMENDS THAT THESE BUILDINGS BE WINDOWLESS TO REDUCE HEAT COSTS, HOWEVER, AT…

  14. WiFeS: the wide field spectrograph

    NASA Astrophysics Data System (ADS)

    Dopita, Michael A.; Waldron, Liam E.; McGregor, Peter; Conroy, Peter; Doolan, Matthew C.; Zhelem, Ross; Bloxham, Gabe; Saunders, Will; Jones, Damien; Pfitzner, Lee

    2004-09-01

    WiFeS is a powerful integral field, double-beam, concentric, image-slicing spectrograph designed to deliver excellent thoughput, precision spectrophotometric performance and superb image quality along with wide spectral coverage throughout the 320-1000 nm wavelength region. It is currently under construction at the Research School of Astronomy and Astrophysics of the Australian National University (ANU), and will be mounted on the ANU 2.3m telescope at Siding Spring Observatory. It will provide a 25x31 arc sec field with 0.5 arc sec sampling along each of twenty five 31x1.0 arc sec slitlets. The output format is arranged to match the 4096x4096 pixel CCD detectors in each of two cameras individually optimized for the blue and the red ends of the spectrum, respectively. A process of "interleaved nod-and-shuffle" will be applied to permit quantum noise-limited sky subtraction. Using VPH gratings, spectral resolutions modes of 3000 and 7000 will be provided. The full spectral range is covered in a single exposure in the R=3000 mode, and in two exposures in the R=7000 mode. The use of transmissive coated optics, VPH gratings and optimized mirror coatings ensures a throughput (including telescope and atmosphere) that peaks above 30%. The concentric image-slicer design ensures an excellent and uniform image quality across the full field. To maximize the scientific return, the whole instrument is configured for remote observing, pipeline data reduction, and the accumulation of calibration image libraries.

  15. AN INTERFACE REGION IMAGING SPECTROGRAPH FIRST VIEW ON SOLAR SPICULES

    SciTech Connect

    Pereira, T. M. D.; De Pontieu, B.; Carlsson, M.; Hansteen, V.; Tarbell, T. D.; Lemen, J.; Title, A.; Boerner, P.; Hurlburt, N.; Wülser, J. P.; Martínez-Sykora, J.; Kleint, L.; Golub, L.; McKillop, S.; Reeves, K. K.; Saar, S.; Testa, P.; Tian, H.; Jaeggli, S.; Kankelborg, C.

    2014-09-01

    Solar spicules have eluded modelers and observers for decades. Since the discovery of the more energetic type II, spicules have become a heated topic but their contribution to the energy balance of the low solar atmosphere remains unknown. Here we give a first glimpse of what quiet-Sun spicules look like when observed with NASA's recently launched Interface Region Imaging Spectrograph (IRIS). Using IRIS spectra and filtergrams that sample the chromosphere and transition region, we compare the properties and evolution of spicules as observed in a coordinated campaign with Hinode and the Atmospheric Imaging Assembly. Our IRIS observations allow us to follow the thermal evolution of type II spicules and finally confirm that the fading of Ca II H spicules appears to be caused by rapid heating to higher temperatures. The IRIS spicules do not fade but continue evolving, reaching higher and falling back down after 500-800 s. Ca II H type II spicules are thus the initial stages of violent and hotter events that mostly remain invisible in Ca II H filtergrams. These events have very different properties from type I spicules, which show lower velocities and no fading from chromospheric passbands. The IRIS spectra of spicules show the same signature as their proposed disk counterparts, reinforcing earlier work. Spectroheliograms from spectral rasters also confirm that quiet-Sun spicules originate in bushes from the magnetic network. Our results suggest that type II spicules are indeed the site of vigorous heating (to at least transition region temperatures) along extensive parts of the upward moving spicular plasma.

  16. SARG: the high-resolution spectrograph of TNG

    NASA Astrophysics Data System (ADS)

    Gratton, Raffaele G.; Bonanno, Giovanni; Bhatia, R.; Cavazza, Andrea; Claudi, Riccardo U.; Ferretti, Flavio

    1997-03-01

    We describe the main features of the optical and mechanical design, and the architecture of the control system of SARG, the white pupil cross dispersed echelle spectrograph for the Italian Telescopio Nazionale Galileo (TNG) telescope. SARG is designed for the spectral range lambda equals 0.37 up to 0.9 micrometer, and for resolution from R equals 19,000 up to R equals 144,000. SARG uses an R4 echelle grating in quasi- Littrow mode; the beam size is 100 mm giving an RS product of RS equals 46,000 at order center. Cross-dispersion is provided by means of a selection of four grisms. A dioptric camera (F/5.05, R equals 144,000) images the cross dispersed spectra on a mosaic of two 2048 by 4096 EEV CCDs (pixel size: 13.5 micrometer). Expected peak efficiency is 0.17 at R equals 38,000, and greater than 0.10 over the whole range from lambda equals 0.4 to 0.9 micrometer. Confocal image slicers, modification of the Bowen-Walraven type designed by Diego, are foreseen for observations at R equals 76,000 (3 slices) and 144,000 (5 slices), allowing high efficiency even in fair seeing conditions. Minimum interorder separation is 8 arcsec. Further features of SARG include an absorbing cell for accurate radial velocities and a Lyot mask (located on an image of the entrance pupil before the slit) for spectrocoronographic observations. SARG is thermally controlled, in order to avoid deterioration of the optical performances.

  17. Faint Object Spectrograph Instrument Handbook v. 6.0

    NASA Astrophysics Data System (ADS)

    Keyes, C. D.; et al.

    1995-06-01

    This Handbook describes The Faint Object Spectrograph (FOS) and its use for Cycle 6 of the Hubble Space Telescope General Observer program. Many presentations have been updated from previous versions, especially those pertaining to target acquisition, brightness limits, and in- strumental sensitivities needed for exposure and S/N calculations. This Handbook draws upon dis- cussions from earlier versions of the Handbook, notably the Version 1.0 FOS Instrument Handbook (Ford 1985), the Supplement to the Version 1.0 Instrument Handbook (Hartig 1989), and the Version 5.0 Handbook (Kinney, 1994). Only the current document should be used for Cy- cle 6. The detectors are described in detail by Harms et al (1979) and Harms (1982). This version of the FOS Instrument Handbook is for the post-COSTAR refurbished tele- scope. The change in focal length introduced by the addition of COSTAR affects the aperture sizes as projected on the sky. However, the pre-COSTAR aperture designations used in the Remote Pro- posal Submission System, version 2 (RPS2) and in the Project Data Base (PDB) have not been changed. Apertures are referred to throughout this document by their size followed in parentheses by their RPS2 exposure level designation (in Courier typeface). Indeed, all RPS2 desig- nations, which are used for proposal preparation, will be denoted in Courier typeface in this Hand- book. For example, the largest circular aperture is referred to as the 0.9'' (1.0) aperture, while the smallest paired apertures are referred to as the 0.09'' paired (0.1-PAIR)apertures.

  18. The Goddard High Resolution Spectrograph Scientific Support Contract

    NASA Technical Reports Server (NTRS)

    1997-01-01

    In 1988, Computer Sciences Corporation (CSC) was selected as the Goddard High Resolution Spectrograph (GHRS) Scientific Support Contractor (SSC). This was to have been a few months before the launch of NASA's first Great Observatory, the Hubble Space Telescope (HST). As one of five scientific instruments on HST, the GHRS was designed to obtain spectra in the 1050-3300 A ultraviolet wavelength region with a resolving power, lambda/Delta(lambda) , of up to 100,000 and relative photometric accuracy to 1%. It was built by Ball AeroSpace Systems Group under the guidance of the GHRS Investigation Definition Team (IDT), comprised of 16 scientists from the US and Canada. After launch, the IDT was to perform the initial instrument calibration and execute a broad scientific program during a five-year Guaranteed Time Observation (GTO) period. After a year's delay, the launch of HST occurred in April 1990, and CSC participated in the in-orbit calibration and first four years of GTO observations with the IDT. The HST primary mirror suffered from spherical aberration, which reduced the spatial and spectral resolution of Large Science Aperture (LSA) observations and decreased the throughput of the Small Science Aperture (SSA) by a factor of two. Periodic problems with the Side 1 carrousel electronics and anomalies with the low-voltage power supply finally resulted in a suspension of the use of Side 1 less than two years after launch. At the outset, the GHRS SSC task involved work in four areas: 1) to manage and operate the GHRS Data Analysis Facility (DAF); 2) to support the second Servicing Mission Observatory Verification (SMOV) program, as well as perform system engineering analysis of the GHRS as nesessary; 3) to assist the GHRS IDT with their scientific research programs, particularly the GSFC members of the team, and 4) to provide administrative and logistic support for GHRS public information and educational activities.

  19. Engineering a highly segmented very wide-field spectrograph

    NASA Astrophysics Data System (ADS)

    Ragazzoni, R.; Fontana, A.; Maccagni, D.; Baruffolo, A.; Bianco, A. G.; diPaola, A.; Farinato, J.; Gentile, G.; Giallongo, E.; Pedichini, F.; Speziali, R.; Testa, V.

    2010-07-01

    The concept of segmenting the focal plane of an existing 8m class telescope in order to fill it with an array of several fast cameras has been developed further and in this work the status of an engineering program aimed to produce a design qualified for the construction, and to assess its cost estimates is presented. The original concept of just having simple cameras with all identical optical components other than a pupil plane corrector to remove the fixed aberrations at the off-axis field of a telescope has been extended to introduce a spectroscopic capability and to assess a trade-off between a very large number (of the order of thousand) of cameras with a small single Field of View with a smaller number of cameras able to compensate the aberration on a much larger Field of View with a combination of different optical elements and different ways to mount and align them. The scientific target of a few thousands multi-slit spectra over a Field of View of a few square degrees, combined with the ambition to mount this on an existing 8m class telescope makes the scientific rationale of such an instrument a very interesting one. In the paper we describe the different options for a possible optical design, the trade off between variations on the theme of the large segmentation and we describe briefly the way this kind of instrument can handle a multi-slit configuration. Finally, the feasibility of the components and a brief description of how the cost analysis is being performed are given. Perspectives on the construction of this spectrograph are given as well.

  20. Redshift Survey of Galaxies around a Selected Sample of Compact Groups

    NASA Astrophysics Data System (ADS)

    de Carvalho, Reinaldo R.; Ribeiro, André L. B.; Capelato, Hugo V.; Zepf, Stephen E.

    We report the results of a spectroscopic survey of faint galaxies in the regions surrounding Hickson compact groups. Our sample is composed of 17 groups within 9000 km s-1. The spectra were taken at the prime focus of the Tololo 4 m telescope, using the ARGUS fiber-fed spectrograph. From these observations, redshifts were determined for the faint galaxies previously identified by de Carvalho, Ribeiro, & Zepf in the surroundings of the groups. Statistical methods were applied to the resultant catalog in order to determine the kinematical structure of each group. This analysis confirms the idea that the Hickson sample of compact groups contains a wide variety of projection and dynamical configurations. Our results demonstrate the necessity of new spectroscopic surveys around compact groups in order to assess their complete velocity distribution.

  1. Progress in Compact Toroid Experiments

    SciTech Connect

    Dolan, Thomas James

    2002-09-01

    The term "compact toroids" as used here means spherical tokamaks, spheromaks, and field reversed configurations, but not reversed field pinches. There are about 17 compact toroid experiments under construction or operating, with approximate parameters listed in Table 1.

  2. X-Spec: A Multi-Object Wideband Survey Spectrograph for CCAT

    NASA Astrophysics Data System (ADS)

    Bradford, Charles; Hailey-Dunsheath, S.; Shirokoff, E.; Hollister, M.; Kovacs, A.; Zmuidzinas, J.; Padin, S.; Seiffert, M. D.; Braun, D.; Banales, G.; LeDuc, H.; Stacey, G. J.; Nikola, T.; Glenn, J.; Chapman, S.

    2013-01-01

    We are developing a multi-object dispersive survey spectrograph for CCAT. X-Spec is optimized for rest-frame far-IR / submm atomic and molecular transitions in high-z galaxies, and it will conduct multi-galaxy spectral survey up to 10x faster than ALMA. Detected lines will provide redshifts for and interstellar gas conditions in tens of thousands of galaxies ranging from the early universe (z > 6) to the present day. X-Spec will be particularly sensitive to the 158-micron ionized carbon fine-structure transition [CII], and the initial instrument will target the 650-um, 850-um, and 1-mm atmospheric windows, corresponding to 3.5 to 9 for [CII]. By following up high-z candidate objects, X-Spec surveys of [CII] will reveal the early evolution of galaxies' energy sources and interstellar gas conditions. CCAT/X-Spec can also probe below individually-detected sources by using fluctuation analyses; the spatial-spectral fluctuations mm and submm bands are dominated by [CII], and can be used to measure the growth of large-scale structure and the global properties of galaxies in the reionization epoch. X-Spec will have at least 15 independent spectrometer backend 'pixels', each covering 195-520 GHz instantaneously at R=400-700, in both polarizations with photon-background-limited sensitivity. It will use lithographically-patterned filterbank chips formed with superconducting transmission line. The detectors are titanium-nitride kinetic inductance detectors (KIDs), and each spectrometer chip will have ~500 KIDs integrated with the filterbank in a package a few square cm in size. Each chip has a bandwidth of ~ 1:1.6 and is single-polarization, so coverage of the full 195-520 GHz range in dual-pol requires 4 chips and ~2000 detectors. With the compact size and inexpensive mass production, much larger spectrometer formats (100-300 pixels) will be possible as detector readout technology progresses. To optimize on-source observation efficiency, a 2-axis rotary positioning system

  3. Space Telescope Imaging Spectrograph Ultraviolet/Optical Spectroscopy of ``Warm'' Ultraluminous Infrared Galaxies

    NASA Astrophysics Data System (ADS)

    Farrah, D.; Surace, J. A.; Veilleux, S.; Sanders, D. B.; Vacca, W. D.

    2005-06-01

    We present high spatial resolution ultraviolet and optical spectroscopy, obtained using the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope, of nuclear structures within four ``warm'' ultraluminous infrared galaxies (ULIRGs). We find an active galactic nucleus (AGN) in at least three and probably all four in our sample, hosted in a compact, optically luminous ``knot.'' In three cases these knots were previously identified as a putative AGN from multiband optical imaging. Three objects of the sample also harbor a starburst in one or more knots, suggesting that the optically luminous knots seen in local ULIRGs are the most likely sites of the dust-shrouded starburst and AGN activity that power the infrared emission. The four AGNs have a diverse range of properties: two are classical narrow-line AGNs, one shows both broad and narrow lines and evidence for lines of sight from the narrow- to the broad-line regions, and one is plausibly an FeLoBAL AGN. The probable presence in one object of an FeLoBAL AGN, which are extremely rare in the QSO population, supports the idea that LoBAL AGNs may be youthful systems shrouded in gas and dust rather than AGNs viewed along a certain line of sight. The three starbursts for which detailed constraints are possible show a smaller range in properties; all three bursts are young, with two having ages of ~4 Myr and the third having an age of 20 Myr, suggesting that ULIRGs undergo several bursts of star formation during their lifetimes. None of the starbursts show evidence for initial mass function slopes steeper than about 3.3. The metallicities of the knots for which metallicities can be derived are all at least 1.5 Zsolar. The properties of one further starburst knot are consistent with it being the forming core of an elliptical galaxy. Our results suggest that detailed studies of the knots seen in ULIRGs can give important insights into the most violent starburst and AGN activity at both low and high redshift.

  4. THE EVOLUTIONARY STATE OF THE PRE-MAIN SEQUENCE POPULATION IN OPHIUCHUS: A LARGE INFRARED SPECTROGRAPH SURVEY

    SciTech Connect

    McClure, M. K.; Espaillat, C.; Calvet, N.; Tobin, J. J. E-mail: ccespa@umich.ed E-mail: jjtobin@umich.ed

    2010-05-15

    Variations in molecular cloud environments have the potential to affect the composition and structure of the circumstellar disks therein. To this end, comparative analyses of nearby star-forming regions are essential to informing theoretical work. In particular, the Ophiuchus molecular clouds are ideal for comparison as they are more compact with much higher extinction than Taurus, the low-mass exemplar, and experience a moderate amount of external radiation. We have carried out a study of a collection of 136 young stellar objects in the <1 Myr old Ophiuchus star-forming region, featuring Spitzer Infrared Spectrograph spectra from 5 to 36 {mu}m, supplemented with photometry from 0.3 {mu}m to 1.3 mm. By classifying these objects using the McClure new molecular cloud extinction law to establish an extinction-independent index, we arrive at a {approx}10% embedded objects fraction, producing an embedded lifetime of 0.2 Myr, similar to that in Taurus. We analyze the degree of dust sedimentation and dust grain processing in the disks, finding that the disks are highly settled with signs of significant dust processing even at {approx}0.3 Myr. Finally, we discuss the wealth of evidence for radial gap structures which could be evidence for disk-planet interactions and explore the effects of stellar multiplicity on the degree of settling and radial structure.

  5. Compact Spreader Schemes

    SciTech Connect

    Placidi, M.; Jung, J. -Y.; Ratti, A.; Sun, C.

    2014-07-25

    This paper describes beam distribution schemes adopting a novel implementation based on low amplitude vertical deflections combined with horizontal ones generated by Lambertson-type septum magnets. This scheme offers substantial compactness in the longitudinal layouts of the beam lines and increased flexibility for beam delivery of multiple beam lines on a shot-to-shot basis. Fast kickers (FK) or transverse electric field RF Deflectors (RFD) provide the low amplitude deflections. Initially proposed at the Stanford Linear Accelerator Center (SLAC) as tools for beam diagnostics and more recently adopted for multiline beam pattern schemes, RFDs offer repetition capabilities and a likely better amplitude reproducibility when compared to FKs, which, in turn, offer more modest financial involvements both in construction and operation. Both solutions represent an ideal approach for the design of compact beam distribution systems resulting in space and cost savings while preserving flexibility and beam quality.

  6. Compact waveguide splitter networks.

    PubMed

    Qian, Yusheng; Song, Jiguo; Kim, Seunghyun; Hu, Weisheng; Nordin, Gregory P

    2008-03-31

    We demonstrate compact waveguide splitter networks in siliconon- insulator (SOI) rib waveguides using trench-based splitters (TBSs) and bends (TBBs). Rather than a 90 degrees geometry, we use 105 degrees TBSs to facilitate reliable fabrication of high aspect ratio trenches suitable for 50/50 splitting when filled with SU8. Three dimensional (3D) finite difference time domain (FDTD) simulation is used for splitter and bend design. Measured TBB and TBS optical efficiencies are 84% and 68%, respectively. Compact 105 degrees 1 x 4, 1 x 8, and 1 x 32 trench-based splitter networks (TBSNs) are demonstrated. The measured total optical loss of the 1 x 32 TBSN is 9.15 dB. Its size is only 700 microm x 1600 microm for an output waveguide spacing of 50 microm. PMID:18542598

  7. Compact power reactor

    DOEpatents

    Wetch, Joseph R.; Dieckamp, Herman M.; Wilson, Lewis A.

    1978-01-01

    There is disclosed a small compact nuclear reactor operating in the epithermal neutron energy range for supplying power at remote locations, as for a satellite. The core contains fuel moderator elements of Zr hydride with 7 w/o of 93% enriched uranium alloy. The core has a radial beryllium reflector and is cooled by liquid metal coolant such as NaK. The reactor is controlled and shut down by moving portions of the reflector.

  8. Compact heat exchangers

    SciTech Connect

    Kays, W.M.; London, A.L.

    1984-01-01

    This third edition is an update of the second edition published in 1964. New data and more modern theoretical solutions for flow in the simple geometries are included, although this edition does not differ radically from the second edition. It contains basic test data for eleven new surface configurations, including some of the very compact ceramic matrices. Al dimensions are given in both the English and the Systeme International (SI) system of units.

  9. Compact infrared detector

    NASA Technical Reports Server (NTRS)

    Gupta, A.; Hong, S.; Moacanin, J.

    1981-01-01

    Broadband IR detector integrated into compact package for pollution monitoring and weather prediction is small, highly responsive, and immune to high noise. Sensing material is transparent sheet metalized with reflecting coating and overcoated with black material on same side. Pulse produced by chopping of infrared source beam creates transient "thermal lens" that temporarily defocuses laser beam probe. Detector monitoring beam measures defocusing which parallels infrared intensity.

  10. Granule consolidation during compaction.

    PubMed

    Rubinstein, M H

    1976-03-01

    The deformation of small cylindrical aggregates of dibasic calcium phosphate was measured during compaction. An analogy between these aggregates and cylindrical granules was proposed. No change in the original shape of the aggregates occurred; the cylindrical shape was maintained even at high compaction pressures. Relaxation of the aggregates occurred at pressures higher than 420 MNm-2 (60.9 x 10(3) lb in.-2) when removed from the compacts, but no relaxation took place at pressures below this value. In addition, the aggregates relaxed by an increase in thickness only; there was no corresponding change in diameter. Up to a pressure of 200 MNm-2 (29.0 x 10(3) lb in.-2), an increase in aggregate diameter occurred, which was accompanied by a reduction in thickness. This change produced only a small reduction in volume, which was attributable to interparticulate slippage resulting in a closer packed arrangement. At a pressure of 200 MNm-2, the aggregate diameter no longer increased because solid bridges were formed between the particles and the die wall, preventing further spreading. From 200 to 420 MNm-2, failure of the material occurred by plastic deformation, which produced only a decrease in aggregate thickness. From 420 to 800 MNm-2 (116.0 x 10(3) lb in.-2), a structure was formed that could support the applied load without further reduction of thickness, and this structure was shown to behave elastically. PMID:1263085

  11. The Cassini Campaign observations of the Jupiter aurora by the Ultraviolet Imaging Spectrograph and the Space Telescope Imaging Spectrograph

    NASA Astrophysics Data System (ADS)

    Ajello, Joseph M.; Pryor, Wayne; Esposito, Larry; Stewart, Ian; McClintock, William; Gustin, Jacques; Grodent, Denis; Gérard, J.-C.; Clarke, John T.

    2005-11-01

    We have analyzed the Cassini Ultraviolet Imaging Spectrometer (UVIS) observations of the Jupiter aurora with an auroral atmosphere two-stream electron transport code. The observations of Jupiter by UVIS took place during the Cassini Campaign. The Cassini Campaign included support spectral and imaging observations by the Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS). A major result for the UVIS observations was the identification of a large color variation between the far ultraviolet (FUV: 1100-1700 Å) and extreme ultraviolet (EUV: 800-1100 Å) spectral regions. This change probably occurs because of a large variation in the ratio of the soft electron flux (10-3000 eV) responsible for the EUV aurora to the hard electron flux (˜15-22 keV) responsible for the FUV aurora. On the basis of this result a new color ratio for integrated intensities for EUV and FUV was defined ( 4πI/4πI) which varied by approximately a factor of 6. The FUV color ratio ( 4πI/4πI) was more stable with a variation of less than 50% for the observations studied. The medium resolution (0.9 Å FWHM, G140M grating) FUV observations (1295-1345 Å and 1495-1540 Å) by STIS on 13 January 2001, on the other hand, were analyzed by a spectral modeling technique using a recently developed high-spectral resolution model for the electron-excited H 2 rotational lines. The STIS FUV data were analyzed with a model that considered the Lyman band spectrum (B Σu+1→XΣg+1) as composed of an allowed direct excitation component (X Σg+1→BΣu+1) and an optically forbidden component (X Σg+1→EF,GK,HH¯,…Σg+1 followed by the cascade transition Σg+1→BΣu+1). The medium-resolution spectral regions for the Jupiter aurora were carefully chosen to emphasize the cascade component. The ratio of the two components is a direct measurement of the mean secondary electron energy of the aurora. The mean secondary electron energy of the aurora varies between 50 and 200 eV for the polar

  12. A ground support electronic interface for the ionospheric spectroscopy and atmospheric chemistry (ISAAC) ultraviolet spectrograph

    NASA Astrophysics Data System (ADS)

    Macquarrie, Jeffrey A.

    1994-12-01

    This thesis details the design and development of an electronic Ground Support Equipment (GSE) interface for the Naval Postgraduate School's (NPS) Ionospheric Spectroscopy and Atmospheric Chemistry (ISAAC) spectrograph. The ISAAC spectrograph, which was designed at NPS and built by Research Support Instruments, Inc., is intended to observe atmospheric airglow and auroral emissions in the ultraviolet (1800A to 3300A) wavelength region. It is to be included as one of several sensors flown onboard the Advanced Research and Global Observation Satellite (ARGOS), which is scheduled for an early 1996 launch. The GSE was developed in order to allow ground testing and calibration of the instrument prior to and during integration with the satellite bus. The GSE includes hardware to provide the connections between various components of the spectrograph and a Macintosh computer with an installed I/O card. The GSE also includes a user-friendly software interface written with LabVIEW 2.2 that provides the ability to view spectra obtained from the instrument and to remotely control mechanical functions of the spectrograph. An initial wavelength calibration of the spectrograph has been performed using the completed GSE.

  13. The cryogenic system for the VIRUS array of spectrographs on the Hobby-Eberly Telescope

    NASA Astrophysics Data System (ADS)

    Smith, Michael P.; Mulholland, George T.; Booth, John A.; Good, John M.; Hill, Gary J.; MacQueen, Phillip J.; Rafal, Marc D.; Savage, Richard D.; Vattiat, Brian L.

    2008-07-01

    The Hobby-Eberly Telescope (HET) is an existing innovative large telescope of 9.2 meter aperture, located at the McDonald Observatory in West Texas. The Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) requires a major upgrade to the HET, including a substantial increase in the telescope field of view, as well as the development and integration of a revolutionary new integral field spectrograph called VIRUS. The Visible Integral-Field Replicable Unit Spectrograph (VIRUS) is an instrument comprising approximately 150 individual IFU-fed spectrographs which will be mounted on the telescope structure. Each spectrograph has a CDD camera detector package which must be cryogenically cooled during scientific operation. In order to cool each of these camera systems a liquid nitrogen system has been proposed and design study completed. The proposed system includes: a liquid nitrogen source, vacuum jacket distribution system, local storage on the telescope, and distribution under a thermal siphon to the individual spectrographs and local thermal connectors.

  14. ECHARPE: a fiber-fed echelle spectrograph for the Pico dos Dias Observatory

    NASA Astrophysics Data System (ADS)

    Dominici, Tania P.; Castilho, Bruno; Gneiding, Clemens D.; Delabre, Bernard A.; Macanhan, Vanessa B. P.; de Arruda, Marcio V.; de Oliveira, Antonio C.; Melendez, Jorge; Vaz, Luiz P. R.; Corradi, Wagner J. B.; Franco, Gabriel A. P.; do Nascimento, Jose D.; Quast, Germano R.; Porto de Mello, Gustavo F.

    2012-09-01

    At least during the last ten years, the Brazilian astronomical community has been asking for an echelle spectrograph for the 1.6 m telescope installed at Pico dos Dias Observatory (Brazópolis, MG, Brazil, OPD/MCTI/LNA). Among the scientific cases are topics related to the chemical evolution of the Galaxy, asteroseismology, chemical composition and chromospheric activities of solar type stars and the relations between solar analogues and terrestrial planets. During 2009 the project finally got started. The called ECHARPE spectrograph (Espectrógrafo ECHelle de Alta Resolução para o telescópio Perkin-Elmer) is being projected to offer a spectral resolution of R ~ 50000, in the range 390-900 nm and with a single exposition. It will be a bench spectrograph with two channels: blue and red, fed by two optical fibers (object, sky or calibration) with aperture of 1.5 or 2.0 arcseconds. The instrument will be placed in one of the telescope pillar ramification, in the originals installations of a Coudé spectrograph and in a specially created environment controlled room. In this work we will present the scientific motivations, the conceptual optical design, the expected performance of the spectrograph, and the status of its development. ECHARPE is expected to be delivered to the astronomical community in 2014, fully prepared and optimized for remote operations.

  15. Photometry of compact galaxies.

    NASA Technical Reports Server (NTRS)

    Shen, B. S. P.; Usher, P. D.; Barrett, J. W.

    1972-01-01

    Photometric histories of the N galaxies 3C 390.3 and PKS 0521-36. Four other compact galaxies, Markarian 9, I Zw 92, 2 Zw 136, and III Zw 77 showed no evidence of variability. The photometric histories were obtained from an exhaustive study of those plates of the Harvard collection taken with large aperture cameras. The images of all galaxies reported were indistinguishable from stars due to the camera f-ratios and low surface brightness of the outlying nebulosities of the galaxies. Standard techniques for the study of variable stars are therefore applicable.

  16. Compact Q-balls

    NASA Astrophysics Data System (ADS)

    Bazeia, D.; Losano, L.; Marques, M. A.; Menezes, R.; da Rocha, R.

    2016-07-01

    In this work we deal with non-topological solutions of the Q-ball type in two space-time dimensions, in models described by a single complex scalar field that engenders global symmetry. The main novelty is the presence of stable Q-balls solutions that live in a compact interval of the real line and appear from a family of models controlled by two distinct parameters. We find analytical solutions and study their charge and energy, and show how to control the parameters to make the Q-balls classically and quantum mechanically stable.

  17. Compact LINAC for deuterons

    SciTech Connect

    Kurennoy, S S; O' Hara, J F; Rybarcyk, L J

    2008-01-01

    We are developing a compact deuteron-beam accelerator up to the deuteron energy of a few MeV based on room-temperature inter-digital H-mode (IH) accelerating structures with the transverse beam focusing using permanent-magnet quadrupoles (PMQ). Combining electromagnetic 3-D modeling with beam dynamics simulations and thermal-stress analysis, we show that IHPMQ structures provide very efficient and practical accelerators for light-ion beams of considerable currents at the beam velocities around a few percent of the speed of light. IH-structures with PMQ focusing following a short RFQ can also be beneficial in the front end of ion linacs.

  18. Compact multiframe blind deconvolution.

    PubMed

    Hope, Douglas A; Jefferies, Stuart M

    2011-03-15

    We describe a multiframe blind deconvolution (MFBD) algorithm that uses spectral ratios (the ratio of the Fourier spectra of two data frames) to model the inherent temporal signatures encoded by the observed images. In addition, by focusing on the separation of the object spectrum and system transfer functions only at spatial frequencies where the measured signal is above the noise level, we significantly reduce the number of unknowns to be determined. This "compact" MFBD yields high-quality restorations in a much shorter time than is achieved with MFBD algorithms that do not model the temporal signatures; it may also provide higher-fidelity solutions. PMID:21403711

  19. Compact Plasma Accelerator

    NASA Technical Reports Server (NTRS)

    Foster, John E.

    2004-01-01

    A plasma accelerator has been conceived for both material-processing and spacecraft-propulsion applications. This accelerator generates and accelerates ions within a very small volume. Because of its compactness, this accelerator could be nearly ideal for primary or station-keeping propulsion for spacecraft having masses between 1 and 20 kg. Because this accelerator is designed to generate beams of ions having energies between 50 and 200 eV, it could also be used for surface modification or activation of thin films.

  20. Compact laser amplifier system

    DOEpatents

    Carr, R.B.

    1974-02-26

    A compact laser amplifier system is described in which a plurality of face-pumped annular disks, aligned along a common axis, independently radially amplify a stimulating light pulse. Partially reflective or lasing means, coaxially positioned at the center of each annualar disk, radially deflects a stimulating light directed down the common axis uniformly into each disk for amplification, such that the light is amplified by the disks in a parallel manner. Circumferential reflecting means coaxially disposed around each disk directs amplified light emission, either toward a common point or in a common direction. (Official Gazette)

  1. Compact gate valve

    DOEpatents

    Bobo, Gerald E.

    1977-01-01

    This invention relates to a double-disc gate valve which is compact, comparatively simple to construct, and capable of maintaining high closing pressures on the valve discs with low frictional forces. The valve casing includes axially aligned ports. Mounted in the casing is a sealed chamber which is pivotable transversely of the axis of the ports. The chamber contains the levers for moving the valve discs axially, and an actuator for the levers. When an external drive means pivots the chamber to a position where the discs are between the ports and axially aligned therewith, the actuator for the levers is energized to move the discs into sealing engagement with the ports.

  2. X-ray spectrometer spectrograph telescope system. [for solar corona study

    NASA Technical Reports Server (NTRS)

    Bruner, E. C., Jr.; Acton, L. W.; Brown, W. A.; Salat, S. W.; Franks, A.; Schmidtke, G.; Schweizer, W.; Speer, R. J.

    1979-01-01

    A new sounding rocket payload that has been developed for X-ray spectroscopic studies of the solar corona is described. The instrument incorporates a grazing incidence Rowland mounted grating spectrograph and an extreme off-axis paraboloic sector feed system to isolate regions of the sun of order 1 x 10 arc seconds in size. The focal surface of the spectrograph is shared by photographic and photoelectric detection systems, with the latter serving as a part of the rocket pointing system control loop. Fabrication and alignment of the optical system is based on high precision machining and mechanical metrology techniques. The spectrograph has a resolution of 16 milliangstroms and modifications planned for future flights will improve the resolution to 5 milliangstroms, permitting line widths to be measured.

  3. UV CCD detectors for WUVS spectrographs of WSO-UV project

    NASA Astrophysics Data System (ADS)

    Shugarov, Andrey; Sachkov, Mikhail; Savanov, Igor; Jaeger, Andreas; Jerram, Paul

    WUVS (WSO-UV Ultra Violet Spectrographs) consists of two high resolution spectrographs (R=50000) covering the Far-UV range of 115-176 nm and the Near-UV range of 174-310 nm, and a long-slit spectrograph (R=1000) covering the wavelength range of 115-305 nm. CCDs for WUVS will be optimized to operate at low level signals. CCD chips with no AR coating for FUV range (<200 nm) and AR coating for NUV range (>200 nm) will be manufactured by e2v company using the enhanced backthinned process. Detectors will operate at the temperature of 173 K with 600 s standard integration time. CCD detectors are optimized for low read-out noise (less than 3e-) and low dark current. The main parameters of WUVS detector subsystems are described.

  4. Development of the MAMA Detectors for the Hubble Space Telescope Imaging Spectrograph

    NASA Technical Reports Server (NTRS)

    Timothy, J. Gethyn

    1997-01-01

    The development of the Multi-Anode Microchannel Array (MAMA) detector systems started in the early 1970's in order to produce multi-element detector arrays for use in spectrographs for solar studies from the Skylab-B mission. Development of the MAMA detectors for spectrographs on the Hubble Space Telescope (HST) began in the late 1970's, and reached its culmination with the successful installation of the Space Telescope Imaging Spectrograph (STIS) on the second HST servicing mission (STS-82 launched 11 February 1997). Under NASA Contract NAS5-29389 from December 1986 through June 1994 we supported the development of the MAMA detectors for STIS, including complementary sounding rocket and ground-based research programs. This final report describes the results of the MAMA detector development program for STIS.

  5. Performance of a laser frequency comb calibration system with a high-resolution solar echelle spectrograph

    NASA Astrophysics Data System (ADS)

    Doerr, H.-P.; Kentischer, T. J.; Steinmetz, T.; Probst, R. A.; Franz, M.; Holzwarth, R.; Udem, Th.; Hänsch, T. W.; Schmidt, W.

    2012-09-01

    Laser frequency combs (LFC) provide a direct link between the radio frequency (RF) and the optical frequency regime. The comb-like spectrum of an LFC is formed by exact equidistant laser modes, whose absolute optical frequencies are controlled by RF-references such as atomic clocks or GPS receivers. While nowadays LFCs are routinely used in metrological and spectroscopic fields, their application in astronomy was delayed until recently when systems became available with a mode spacing and wavelength coverage suitable for calibration of astronomical spectrographs. We developed a LFC based calibration system for the high-resolution echelle spectrograph at the German Vacuum Tower Telescope (VTT), located at the Teide observatory, Tenerife, Canary Islands. To characterize the calibration performance of the instrument, we use an all-fiber setup where sunlight and calibration light are fed to the spectrograph by the same single-mode fiber, eliminating systematic effects related to variable grating illumination.

  6. Multi-mode spectrographs for small telescopes: design, operation, performances and results

    NASA Astrophysics Data System (ADS)

    Munari, U.; Valisa, P.

    2014-03-01

    We present three generations (Mark.I, II and III) of spectrographs we put into operation with ANS Collaboration 0.61m, 0.70m and 0.84m telescopes. These spectrographs are of the Multi-Mode type, allowing for rapid interchange between Echelle high dispersion and two separate single dispersion modes (low and medium resolution). All three modes are long-slit, rotate to any angle (including parallactic compensation for atmospheric dispersion), allow to select among different comparison lamps, and are auto-guided by TV imaging the slit, which is continuously adjustable in width and by a step decker in height. The latest Mark.III model adds many new features including remote operation, spatial splitting of order overlap in single dispersion modes, interchange between prism and grating cross-dispersion in the Echelle mode, spectropolarimetry, a coronagraphic mode and direct filtered imaging without removing the spectrograph from the Cassegrain focus.

  7. Using the CeSiC material for the WSO-UV spectrographs

    NASA Astrophysics Data System (ADS)

    Reutlinger, A.; Sachkov, M.; Gál, C.; Brandt, C.; Haberler, P.; Zuknik, K.-H.; Sedlmaier, T.; Shustov, B.; Moisheev, A.; Kappelmann, N.; Barnstedt, J.; Werner, K.

    2011-09-01

    The World Space Observatory Ultraviolet (WSO-UV) is a multi-national project lead by the Russian Federal Space Agency (Roscosmos) with the objective of high performance observations in the ultraviolet range. The 1.7 m WSO-UV telescope is equipped with UV spectrographs (responsibility of Russia and Germany) and UV imagers (responsibility of Spain). The UV spectroscopic instrumentation comprises two high resolution echelle spectrographs operating in wavelength ranges of 102-176 nm and 174-310 nm respectively, and a Long Slit Spectrograph designed to operate in the range of 102-310 nm. All three spectrographs represent individual instruments. In order to save mass while maintaining high stiffness, the instruments are combined to a monoblock, World Space Observatory Ultraviolet Spectrographs (WUVS). Due to strict technical requirements stated by the customer the material CeSiC (provided by the company ECM) has been selected for the design of the spectrograph structure. In contrast to aluminium, the stable structure of CeSiC is significantly less sensitive to thermal gradients. No further mechanism for focus correction with high functional, technical and operational complexity and corresponding additional System costs are necessary. Using CeSiC also relaxes the thermal control requirements of ±5°C, which represents a considerable cost driver for the S/C design. The phase B2 study of the WUVS instrument finished in December 2010 in collaboration with Russia and with industrial support of the Kayser-Threde company. It included construction of a Structural Thermal Model (STM) for verification of thermal and mechanical loads, stability with respect to thermal distortions and CeSiC manufacturing feasibility.

  8. Compaction of Titanium Powders

    SciTech Connect

    Stephen J. Gerdemann; Paul D. Jablonski

    2010-11-01

    Accurate modeling of powder densification has been an area of active research for more than 60 years. The earliest efforts were focused on linearization of the data because computers were not readily available to assist with curve-fitting methods. In this work, eight different titanium powders (three different sizes of sponge fines <150 μm, <75 μm, and < 45 μm; two different sizes of a hydride-dehydride [HDH] <75 μm and < 45 μm; an atomized powder; a commercially pure [CP] Ti powder from International Titanium Powder [ITP]; and a Ti 6 4 alloy powder) were cold pressed in a single-acting die instrumented to collect stress and deformation data during compaction. From these data, the density of each compact was calculated and then plotted as a function of pressure. The results show that densification of all the powders, regardless of particle size, shape, or chemistry, can be modeled accurately as the sum of an initial density plus the sum of a rearrangement term and a work-hardening term. These last two terms are found to be a function of applied pressure and take the form of an exponential rise.

  9. Compact electrostatic comb actuator

    DOEpatents

    Rodgers, M. Steven; Burg, Michael S.; Jensen, Brian D.; Miller, Samuel L.; Barnes, Stephen M.

    2000-01-01

    A compact electrostatic comb actuator is disclosed for microelectromechanical (MEM) applications. The actuator is based upon a plurality of meshed electrostatic combs, some of which are stationary and others of which are moveable. One or more restoring springs are fabricated within an outline of the electrostatic combs (i.e. superposed with the moveable electrostatic combs) to considerably reduce the space required for the actuator. Additionally, a truss structure is provided to support the moveable electrostatic combs and prevent bending or distortion of these combs due to unbalanced electrostatic forces or external loading. The truss structure formed about the moveable electrostatic combs allows the spacing between the interdigitated fingers of the combs to be reduced to about one micron or less, thereby substantially increasing the number of active fingers which can be provided in a given area. Finally, electrostatic shields can be used in the actuator to substantially reduce unwanted electrostatic fields to further improve performance of the device. As a result, the compact electrostatic comb actuator of the present invention occupies only a fraction of the space required for conventional electrostatic comb actuators, while providing a substantial increase in the available drive force (up to one-hundred times).

  10. Measured Pre-Flight Performance of the Extreme Ultraviolet Normal Incidence Spectrograph (EUNIS)

    NASA Astrophysics Data System (ADS)

    Thomas, R. J.; Rabin, D. M.; Nowak, M. D.; Gum, J. S.; Seely, J. F.; Seshadri, S.; Siegmund, O. H.

    2005-05-01

    The Extreme Ultraviolet Normal-Incidence Spectrograph (EUNIS) is a sounding rocket experiment that will investigate the energetics of the solar corona and hotter transition region through high-resolution imaging spectroscopy with a rapid (2 s) cadence. EUNIS features independent optical systems to record spatially co-aligned spectra over the two bandpasses 170--205 Å and 300--370 Å simultaneously. All the components in the detection chain have been characterized, including multilayer telescope mirrors, lithographic slits, multilayer diffraction gratings, microchannel plate intensifiers, and active pixel sensors. The results demonstrate that EUNIS is the most sensitive solar EUV spectrograph in existence. Its first flight is scheduled for 2005 August.

  11. AVES-IMCO: an adaptive optics visible spectrograph and imager/coronograph for NAOS

    NASA Astrophysics Data System (ADS)

    Beuzit, Jean-Luc; Lagrange, A.-M.; Mouillet, D.; Chauvin, G.; Stadler, E.; Charton, J.; Lacombe, F.; AVES-IMCO Team

    2001-05-01

    The NAOS adaptive optics system will very soon provide diffraction-limited images on the VLT, down to the visible wavelengths (0.020 arcseconds at 0.83 micron for instance). At the moment, the only instrument dedicated to NAOS is the CONICA spectro-imager, operating in the near-infrared from 1 to 5 microns. We are now proposing to ESO, in collaboration with an Italian group, the development of a visible spectrograph/imager/coronograph, AVES-IMCO (Adaptive Optics Visual Echelle Spectrograph and IMager/COronograph). We present here the general concept of the new instrument as well as its expected performances in the different modes.

  12. Performance testing of an off-plane reflection grating and silicon pore optic spectrograph at PANTER

    NASA Astrophysics Data System (ADS)

    Marlowe, Hannah; McEntaffer, Randall L.; Allured, Ryan; DeRoo, Casey T.; Donovan, Benjamin D.; Miles, Drew M.; Tutt, James H.; Burwitz, Vadim; Menz, Benedikt; Hartner, Gisela D.; Smith, Randall K.; Cheimets, Peter; Hertz, Edward; Bookbinder, Jay A.; Günther, Ramses; Yanson, Alex; Vacanti, Giuseppe; Ackermann, Marcelo

    2015-10-01

    An x-ray spectrograph consisting of aligned, radially ruled off-plane reflection gratings and silicon pore optics (SPO) was tested at the Max Planck Institute for Extraterrestrial Physics PANTER x-ray test facility. SPO is a test module for the proposed Arcus mission, which will also feature aligned off-plane reflection gratings. This test is the first time two off-plane gratings were actively aligned to each other and with an SPO to produce an overlapped spectrum. We report the performance of the complete spectrograph utilizing the aligned gratings module and plans for future development.

  13. The SCR flare of 16 February 1984 as recorded by the Sayan spectrograph

    NASA Technical Reports Server (NTRS)

    Koslov, S. A.; Pakhomov, N. I.; Shapovalova, L. A.; Yanchukovsky, A. L.

    1985-01-01

    The Sayan cosmic ray (CR) spectrograph recorded an SCR flare that occurred on 16 February 1984. Data from both 1-hour and 110-minute duration measurements in 10 channels with different energy sensitivity (of neutron monitors HM-64 located at different depths in the atmosphere, and of a neutron, multiple neutron and rigid mumeson component lead-less detector) is presented. The parameters of the SCR variation spectrum are evaluated and it is shown that the recording of multiple neutrons at the same geographic point and at the same level in the atmosphere provides information similar to that from a spectrographic complex of instruments.

  14. BESO: first light at the high-resolution spectrograph for the Hexapod-Telescope

    NASA Astrophysics Data System (ADS)

    Steiner, Ingo; Stahl, Otmar; Seifert, Walter; Chini, Rolf; Quirrenbach, Andreas

    2008-07-01

    BESO (Bochum Echelle Spectrograph for OCA)is a high-resolution echelle spectrograph which has been built by Ruhr-Universitaet, Bochum and Landessternwarte Heidelberg. It is fiber-coupled to the 1.5m Hexapod-Telescope at the Observatario Cerro Armazones (OCA), Chile. The first light spectra show that the resolution of 48.000 over a spectral range from 370 nm to 840 nm has been achieved. An alignment by design approach has been followed to assemble the fiber-head optics at the telescope side of fiber coupled instrument.

  15. Mechanical and thermal design challenges in building a semi-cold near infrared spectrograph: the Robert Stobie -Near Infrared Spectrograph for SALT

    NASA Astrophysics Data System (ADS)

    Smith, Michael P.; Adler, Douglas P.; Jaehnig, Kurt P.; Wolf, Marsha J.; Smee, Stephen; Bartosz, Curtis; Garot, Kristine; Mason, William P.; Mulligan, Mark P.; Percival, Jeffrey W.; Thielman, Donald J.; Wong, Jeffrey P.

    2014-07-01

    The near infrared upgrade to the Robert Stobie Spectrograph (RSS/NIR) for the Southern African Large Telescope (SALT) extends the capabilities of the visible arm RSS into the Near Infrared (NIR). In order to extend into the NIR range, the upgrade components of the instrument are required to be cooled. Thus the NIR arm is predominantly housed in the instrument pre-dewar which is cooled to -40°C, at ambient pressure. The multiple modes, prime focus location and partially cooled instrument introduce interesting engineering considerations. The NIR spectrograph has an ambient temperature collimator, a cooled (-40°C) dispersers and camera and a cryogenic detector. The cryogenic dewar and many of the mechanisms are required to operate within the cooled, atmospheric environment. Cooling the pre-dewar to - 40°C at prime focus of the telescope is also an engineering challenge. Mechanical and thermal aspects of the design are addressed in this paper with a particular emphasis on the unique considerations of building a semi-warm infrared spectrograph.

  16. METHOD OF FORMING ELONGATED COMPACTS

    DOEpatents

    Larson, H.F.

    1959-05-01

    A powder compacting procedure and apparatus which produces elongated compacts of Be is described. The powdered metal is placed in a thin metal tube which is chemically compatible to lubricant, powder, atmosphere, and die material and will undergo a high degree of plastic deformation and have intermediate hardness. The tube is capped and placed in the die, and punches are applied to the ends. During the compacting stroke the powder seizes the tube and a thickening and shortening of the tube occurs. The tube is easily removed from the die, split, and peeled from the compact. (T.R.H.)

  17. An Efficient, Compact, and Versatile Fiber Double Scrambler for High Precision Radial Velocity Instruments

    NASA Astrophysics Data System (ADS)

    Halverson, Samuel; Roy, Arpita; Mahadevan, Suvrath; Ramsey, Lawrence; Levi, Eric; Schwab, Christian; Hearty, Fred; MacDonald, Nick

    2015-06-01

    We present the design and test results of a compact optical fiber double-scrambler for high-resolution Doppler radial velocity instruments. This device consists of a single optic: a high-index n ∼ 2 ball lens that exchanges the near and far fields between two fibers. When used in conjunction with octagonal fibers, this device yields very high scrambling gains (SGs) and greatly desensitizes the fiber output from any input illumination variations, thereby stabilizing the instrument profile of the spectrograph and improving the Doppler measurement precision. The system is also highly insensitive to input pupil variations, isolating the spectrograph from telescope illumination variations and seeing changes. By selecting the appropriate glass and lens diameter the highest efficiency is achieved when the fibers are practically in contact with the lens surface, greatly simplifying the alignment process when compared to classical double-scrambler systems. This prototype double-scrambler has demonstrated significant performance gains over previous systems, achieving SGs in excess of 10,000 with a throughput of ∼87% using uncoated Polymicro octagonal fibers. Adding a circular fiber to the fiber train further increases the SG to >20,000, limited by laboratory measurement error. While this fiber system is designed for the Habitable-zone Planet Finder spectrograph, it is more generally applicable to other instruments in the visible and near-infrared. Given the simplicity and low cost, this fiber scrambler could also easily be multiplexed for large multi-object instruments.

  18. Compact vacuum insulation embodiments

    DOEpatents

    Benson, D.K.; Potter, T.F.

    1992-04-28

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially point' or line' contacts with the metal wall sheets. In the case of monolithic spacers that form line' contacts, two such spacers with the line contacts running perpendicular to each other form effectively point' contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included. 26 figs.

  19. Compact vacuum insulation

    DOEpatents

    Benson, D.K.; Potter, T.F.

    1993-01-05

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially point'' or line'' contacts with the metal wall sheets. In the case of monolithic spacers that form line'' contacts, two such spacers with the line contacts running perpendicular to each other form effectively point'' contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included.

  20. Compact vacuum insulation

    DOEpatents

    Benson, David K.; Potter, Thomas F.

    1993-01-01

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially "point" or "line" contacts with the metal wall sheets. In the case of monolithic spacers that form "line" contacts, two such spacers with the line contacts running perpendicular to each other form effectively "point" contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included.

  1. Compact vacuum insulation embodiments

    DOEpatents

    Benson, David K.; Potter, Thomas F.

    1992-01-01

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially "point" or "line" contacts with the metal wall sheets. In the case of monolithic spacers that form "line" contacts, two such spacers with the line contacts running perpendicular to each other form effectively "point" contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included.

  2. Compact acoustic refrigerator

    DOEpatents

    Bennett, Gloria A.

    1992-01-01

    A compact acoustic refrigeration system actively cools components, e.g., electrical circuits (22), in a borehole environment. An acoustic engine (12, 14) includes first thermodynamic elements (12) for generating a standing acoustic wave in a selected medium. An acoustic refrigerator (16, 26, 28) includes second thermodynamic elements (16) located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements (16) and a relatively hot temperature at a second end of the second thermodynamic elements (16). A resonator volume (18) cooperates with the first and second thermodynamic elements (12, 16) to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements (12, 16), first heat pipes (24, 26) transfer heat from the heat load (22) to the second thermodynamic elements (16) and second heat pipes (28, 32) transfer heat from first and second thermodynamic elements (12, 16) to the borehole environment.

  3. Compact SPS - Power delivery

    NASA Astrophysics Data System (ADS)

    Pospisil, M.; Pospisilova, L.

    1982-09-01

    The power deliverable by a compact solar Space Power Station (SPS) is a function of its outer surface shape. Methods of fitting the power delivery curve of such a system to different patterns of daily power demand are considered that involve the appropriate choice of the number of satellites, their maximal power, height to width ratio and the shift of longitude with respect to the receiving station. Changes in the daily delivery curve can be made by altering the longitudes and orientations of the satellites. Certain limitations to the choice of parameters exist, such as: the height to width ratio should be near 1.2, and the sum of longitude and orientation changes will probably not be greater than 50 deg. The optimization of the peak to average power ratio is also discussed.

  4. Multipurpose Compact Spectrometric Unit

    SciTech Connect

    Bocarov, Viktor; Cermak, Pavel; Mamedov, Fadahat; Stekl, Ivan

    2009-11-09

    A new standalone compact spectrometer was developed. The device consists of analog (peamplifier, amplifier) and digital parts. The digital part is based on the 160 MIPS Digital Signal Processor. It contains 20 Msps Flash-ADC, 1 MB RAM for spectra storage, 128 KB Flash/ROM for firmware storage, Real Time Clock and several voltage regulators providing the power for user peripherals (e.g. amplifier, temperature sensors, etc.). Spectrometer is connected with a notebook via high-speed USB 2.0 bus. The spectrometer is multipurpose device, which is planned to be used for measurements of Rn activities, energy of detected particles by CdTe pixel detector or for coincidence measurements.

  5. Compact ultraviolet laser

    NASA Astrophysics Data System (ADS)

    Baird, Brian Walter

    1997-09-01

    This dissertation presents theoretical analysis and experimental investigation of a compact ultraviolet laser, comprising an unstable resonator semiconductor (URSL) laser-pumped potassium titanyl phosphate (KTP) periodically segmented waveguide (PSW) laser. A comprehensive survey of existing short wavelength visible and near ultraviolet laser technologies suitable for the development of compact ultraviolet lasers is presented. This survey establishes the suitability of a diode-pumped KTP PSW laser as an attractive approach for developing a compact ultraviolet laser. Requirements for an efficient diode-pumped KTP PSW laser are given, leading to the selection of a frequency-stabilized URSL and hydrothermal KTP PSWs as the component technologies to be developed and integrated. Since the design requirements for the URSL and KTP PSW are critically dependent on a thorough understanding of the spatial mode properties of KTP PSWs, analyses and modeling of the spatial mode properties of these devices is presented using effective index method (EIM) and beam propagation method (BPM) models. In addition, a new expression for the normalized conversion efficiency is presented which explicitly incorporates the dependence of this important parameter on the lateral variation of the refractive index and d coefficient. To assess the theoretical performance of an URSL-pumped KTP PSW, the BPM model was extended to incorporate second harmonic generation. This represents an important contribution to the development of numerical methods for modeling nonlinear waveguides, in general, and provides important information on the cooperative effects of diffraction and spatial mode beating on the SHG output from KTP PSWs. Extensive optical characterization of NUV SHG in hydrothermal KTP PSWs using an argon-ion laser-pumped Ti:Sapphire laser as the infrared laser pump source is presented. Spectral characterization, spatial mode characterization, and the temperature dependence of the QPM

  6. Compact acoustic refrigerator

    SciTech Connect

    Bennett, G.A.

    1991-12-31

    This invention is comprised of a compact acoustic refrigeration system that actively cools components, e.g., electrical circuits, in a borehole environment. An acoustic engine includes first thermodynamic elements for generating a standing acoustic wave in a selected medium. An acoustic refrigerator includes second thermodynamic elements located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements and a relatively hot temperature at a second end of the second thermodynamic elements. A resonator volume cooperates with the first and second thermodynamic elements to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements, first heat pipes transfer heat from the heat load to the second thermodynamic elements and second heat pipes transfer heat from first and second thermodynamic elements to the borehole environment.

  7. Compact acoustic refrigerator

    DOEpatents

    Bennett, G.A.

    1992-11-24

    A compact acoustic refrigeration system actively cools components, e.g., electrical circuits, in a borehole environment. An acoustic engine includes first thermodynamic elements for generating a standing acoustic wave in a selected medium. An acoustic refrigerator includes second thermodynamic elements located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements and a relatively hot temperature at a second end of the second thermodynamic elements. A resonator volume cooperates with the first and second thermodynamic elements to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements, first heat pipes transfer heat from the heat load to the second thermodynamic elements and second heat pipes transfer heat from first and second thermodynamic elements to the borehole environment. 18 figs.

  8. Compact artificial hand

    NASA Technical Reports Server (NTRS)

    Wiker, G. A.; Mann, W. A. (Inventor)

    1979-01-01

    A relatively simple, compact artificial hand, is described which includes hooks pivotally mounted on first frame to move together and apart. The first frame is rotatably mounted on a second frame to enable "turning at the wrist" movement without limitation. The second frame is pivotally mounted on a third frame to permit 'flexing at the wrist' movement. A hook-driving motor is fixed to the second frame but has a shaft that drives a speed reducer on the first frame which, in turn, drives the hooks. A second motor mounted on the second frame, turns a gear on the first frame to rotate the first frame and the hooks thereon. A third motor mounted on the third frame, turns a gear on a second frame to pivot it.

  9. Most Efficient Spectrograph to Shoot the Southern Skies

    NASA Astrophysics Data System (ADS)

    2009-05-01

    -shooter, for a total of 350 observing nights, making it the second most requested instrument at the Very Large Telescope in this period. More information ESO's Very Large Telescope (VLT) is the world's most advanced optical instrument. It is an ensemble of four 8.2-metre telescopes located at the Paranal Observatory on an isolated mountain peak in the Atacama Desert in North Chile. The four 8.2-metre telescopes have a total of 12 focal stations where different instruments for imaging and spectroscopic observations are installed and a special station where the light of the four telescopes is combined for interferometric observations. The first VLT instrument was installed in 1998 and has been followed by 12 more in the last 10 years, distributed at the different focal stations. X-shooter is the first of the second generation of VLT instruments and replaces the workhorse-instrument FORS1, which has been successfully used for more than ten years by hundreds of astronomers. X-shooter operates at the Cassegrain focus of the Kueyen telescope (UT2). In response to an ESO Call for Proposals for second generation VLT instrumentation, ESO received three proposals for an intermediate resolution, high efficiency spectrograph. These were eventually merged into a single proposal around the present concept of X-shooter, which was approved for construction in November 2003. The Final Design Review, at which the instrument design is finalised and declared ready for construction, took place in April 2006. The first observations with the instrument at the telescope in its full configuration were on 14 March 2009. X-shooter is a joint project by Denmark, France, Italy, the Netherlands and ESO. The collaborating institutes in Denmark are the Niels Bohr and the DARK Institutes of the University of Copenhagen and the National Space Institute (Technical University of Denmark); in France GEPI at the Observatoire de Paris and APC at the Université D. Diderot, with contributions from the CEA and the

  10. Effect of Acoustic Spectrographic Instruction on Production of English /i/ and /I/ by Spanish Pre-Service English Teachers

    ERIC Educational Resources Information Center

    Quintana-Lara, Marcela

    2014-01-01

    This study investigates the effects of Acoustic Spectrographic Instruction on the production of the English phonological contrast /i/ and / I /. Acoustic Spectrographic Instruction is based on the assumption that physical representations of speech sounds and spectrography allow learners to objectively see and modify those non-accurate features in…

  11. The Coude spectrograph and echelle scanner of the 2.7 m telescope at McDonald observatory

    NASA Technical Reports Server (NTRS)

    Tull, R. G.

    1972-01-01

    The design of the Coude spectrograph of the 2.7 m McDonald telescope is discussed. A description is given of the Coude scanner which uses the spectrograph optics, the configuration of the large echelle and the computer scanner control and data systems.

  12. Effect of Training Japanese L1 Speakers in the Production of American English /r/ Using Spectrographic Visual Feedback

    ERIC Educational Resources Information Center

    Patten, Iomi; Edmonds, Lisa A.

    2015-01-01

    The present study examines the effects of training native Japanese speakers in the production of American /r/ using spectrographic visual feedback. Within a modified single-subject design, two native Japanese participants produced single words containing /r/ in a variety of positions while viewing live spectrographic feedback with the aim of…

  13. An optical spectrograph design for a new-generation multiple object Doppler instrument

    NASA Astrophysics Data System (ADS)

    Zhao, Bo; Ge, Jian

    2006-06-01

    This paper describes an optical spectrograph design for the W.M. Keck Exoplanet Tracker (ET) multi-object Doppler radial velocity instrument. The Keck ET is currently installed at the Sloan 2.5m telescope (Ge et al. this proceedings), and is capable of simultaneously monitoring 60 stars with high precision for a planet survey. The spectrograph consists of an entrance slit, collimator optics, a Volume Phase Holographic (VPH) grating, camera optics and a 4kx4k CCD camera, and provides a spectral resolution of R =5000, with a 180 mm diameter collimated beam. The collimator and camera optics (300 mm largest diameter) are made of two standard optical grade glasses: BK7 and F2, respectively. The spectrograph is transmissive and optimized for delivering high throughput and high image quality over the entire operation bandwidth: 500-590 nm. The f/4 input beams from the Keck ET interferometer are converted to f/1.5 beams on the detector by this spectrograph, and form 60 stellar fringe spectra.

  14. The solar-stellar spectrograph: Project description, data calibration, and initial results

    NASA Astrophysics Data System (ADS)

    Hall, Jeffrey C.; Lockwood, G. W.

    1995-01-01

    The Solar-Stellar Spectrograph (SSS) is a project initiated in the 1980s by scientists from the High Altitude Observatory, Lowell Observatory, the Pennsylvania State Universty, and the Sacramento Peak Observatory. The instrument is comprised of two spectrographs: one is an echelle covering the wavelength range lambda lambda 5000-9200, while the second is a Littrow spectrograph covering the Ca II and H and K region around lambda 3950. This project is designed to address a broad range of outstanding questions regarding the nature of stellar activity cycles. The unique capability of the spectrograph is its ability to record both solar and stellar spectra, allowing more accurate placement of the Sun in the stellar context than has been feasible previously. In this report we discuss the motivation for this project, the instrumental characteristics, the observing programs, the methods being used to reduce, calibrate, and analyze the data, and the connection of our databases to extant databases. A central part of the discussion is the connection of the Sun with the stars both in terms of existing solar and stellar activity indices as well as physical flux. This work resolves a long-standing discrepancy in this area and establishes a protocol for relating the large set of observations from the Mount Wilson Ca II H and K project to physical flux, in preparation for future comparison to our observations and results from theory.

  15. VIRUS-P: A Powerful Integral Field Spectrograph Designed For Replication

    NASA Astrophysics Data System (ADS)

    Hill, Gary J.; MacQueen, P. J.; Adams, J.; Tufts, J.; Blanc, G.; Smith, M. P.; Roth, M. M.; Kelz, A.; Segura, P.; Gebhardt, K.; Good, J.; Drory, N.

    2007-12-01

    The Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) will outfit the 10 m HET with a new wide field and an array of 145 integral-field spectrographs to survey a 400 sq. degree area in the north galactic cap. Each fiber-coupled unit spectrograph will cover 350-590 nm, simultaneously at 5 A resolution, providing 40,000 spectra per exposure. This instrument, called VIRUS, will open up surveys of the emission-line universe for the first time, and in particular will be used to detect 1 million Lyman-alpha emitting (LAE) galaxies with 1.9 < z < 3.8. The prototype of the VIRUS unit spectrograph (VIRUS-P) is a powerful instrument in its own right. Used on the McDonald 2.7 m Smith reflector, it covers the largest area of any integral field spectrograph, and has coverage down to 340 nm. It is currently in use for a pilot survey to better measure the properties of LAE galaxies in support of HETDEX, among other investigations where it is uniquely powerful. We report details of the VIRUS-P design and its performance. VIRUS-P has been made possible by a generous donation from the Cynthia and George Mitchell Foundation. This work is supported by Texas Advanced Research Program Grant No. 003658-0005-2006

  16. Update on the Gemini High-Resolution Optical SpecTrograph (GHOST)

    NASA Astrophysics Data System (ADS)

    Margheim, Steven J.; Ghost Instrument Team

    2015-01-01

    The Gemini High-Resolution Opitcal SpecTrograph (GHOST) is under development for the Gemini telescopes in collaboration with the Austrailian Astronomical Observatory (AAO), the NRC-Herzberg in Canada, and the Australian National University (ANU). The latest design and project plan will be presented and the scientific role of the instrument will be discussed.

  17. Theory and computation of three cosmic origin spectrograph aspheric gratings recorded with a multimode deformable mirror.

    PubMed

    Duban, M

    1999-03-01

    The theory of three Cosmic Origin Spectrograph holographic gratings recorded with a deformable plane mirror is presented. Their working conditions are severe, since they have to correct the strong spherical aberration and the field astigmatism of the Hubble Space Telescope. Recorded on aspherized substrates, the gratings produce images that are diffraction limited with regard to spectral resolution. PMID:18305717

  18. A spectrograph for exoplanet observations calibrated at the centimetre-per-second level.

    PubMed

    Wilken, Tobias; Curto, Gaspare Lo; Probst, Rafael A; Steinmetz, Tilo; Manescau, Antonio; Pasquini, Luca; González Hernández, Jonay I; Rebolo, Rafael; Hänsch, Theodor W; Udem, Thomas; Holzwarth, Ronald

    2012-05-31

    The best spectrographs are limited in stability by their calibration light source. Laser frequency combs are the ideal calibrators for astronomical spectrographs. They emit a spectrum of lines that are equally spaced in frequency and that are as accurate and stable as the atomic clock relative to which the comb is stabilized. Absolute calibration provides the radial velocity of an astronomical object relative to the observer (on Earth). For the detection of Earth-mass exoplanets in Earth-like orbits around solar-type stars, or of cosmic acceleration, the observable is a tiny velocity change of less than 10 cm s(-1), where the repeatability of the calibration--the variation in stability across observations--is important. Hitherto, only laboratory systems or spectrograph calibrations of limited performance have been demonstrated. Here we report the calibration of an astronomical spectrograph with a short-term Doppler shift repeatability of 2.5 cm s(-1), and use it to monitor the star HD 75289 and recompute the orbit of its planet. This repeatability should make it possible to detect Earth-like planets in the habitable zone of star or even to measure the cosmic acceleration directly. PMID:22660320

  19. An Imaging Spectrograph for Ground Based, Round-the-Clock Optical Aeronomy Studies

    NASA Astrophysics Data System (ADS)

    Chakrabarti, S.; Pallamraju, D.

    2004-12-01

    In recent years we have developed a high resolution imaging spectrograph at Boston University that is capable of unambiguously measuring faint airglow/auroral emissions buried in the bright solar background continuum of the daytime (solar zenith angle < 90 deg) sky. Two versions of this instrument have been developed. A multi-wavelength implementation, called High Throughput Imaging Echelle Spectrograph (HiTIES), has been used to simultaneously measure several twilighttime/nighttime optical emissions located anywhere in the visible range at moderate (0.03 nm) resolution, while the High Resolution Imaging Spectrograph using Echelle grating (HIRISE) has been used to study daytime airglow and auroral emissions at higher (0.01 nm) resolution. Both of these rugged instruments have been deployed at Boston University as well as other sites (Sondre Stromfjord, Carmen Alto and Svaalbard) without any technical difficulties. They have been used to investigate such wide-ranging aeronomy problems as 630.0nm dayglow, forecasting of Equatorial Spread F development, sunlit cusp as well as the daytime aurora over Boston on October 30, 2003. These proof-of-concept experiments have demonstrated the value of this new tool for future studies of the dynamical processes in space physics and aeronomy. We are presently incorporating improved capabilities and have plans to deploy more than one spectrograph simultaneously for tomographic applications. In this paper we will review the scientific contributions we have made with these two instruments, our future plans and outline their possible role in the International Heliophysical Year.

  20. A dual-channel, focusing x-ray spectrograph with uniform dispersion for Z pinch plasmas measurement

    SciTech Connect

    Yang Qingguo; Li Zeren; Chen Guanhua; Ye Yan; Huang Xianbin; Cai Hongchun; Li Jing; Xiao Shali

    2012-01-15

    A dual-channel, focusing x-ray spectrograph with uniform dispersion (i.e., the linear dispersion of this spectrograph is a constant) is described for measuring the x-ray spectra emission from the hot, dense Al Z pinch plasmas. The spectrograph uses double uniform-dispersed crystals (e.g., a Quartz 1010 crystal and a Mica 002 crystal) as dispersion elements and a double-film box as detector to achieve the simultaneous recording of the time integrated spectrum covering a wide spectral range of {approx}5-9 A. Since this spectrograph disperse the x-rays on the detector plane with uniform spacing for every wavelength, it needs not the calibration of the wavelength with spatial coordinate, thereby own the advantages of easiness and veracity for spectra identification. The design of this spectrograph and the example of experiment on the ''Yang'' accelerator are presented.

  1. Compost improves compacted urban soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Urban construction sites usually result in compacted soils that limit infiltration and root growth. The purpose of this study was to determine if compost, aeration, and/or prairie grasses can remediate a site setup as a simulated post-construction site (compacted). Five years after establishing the ...

  2. The Meaning of a Compact

    ERIC Educational Resources Information Center

    Wasescha, Anna

    2016-01-01

    To mark the 30th anniversary of "Campus Compact," leaders from across the network came together in the summer of 2015 to reaffirm a shared commitment to the public purposes of higher education. Campus Compact's 30th Anniversary Action Statement of Presidents and Chancellors is the product of that collective endeavor. In signing the…

  3. An Innovative Combination of Fiber Scrambling and Image Slicing for High Resolution Spectrographs

    NASA Astrophysics Data System (ADS)

    Kaplan, Zachary; Spronck, J. F. P.; Fischer, D. A.; Schwab, C.

    2012-05-01

    The detection of Earth-like exoplanets with the radial velocity method requires extreme Doppler precision and long-term stability in order to measure tiny reflex velocities in the host star. Recent planet searches have led to the detection of so called “super-Earths” (up to a few Earth masses) that induce radial velocity changes of about 1 m/s. However, the detection of true Earth analogs requires a precision of 10 cm/s. Image slicers have been used since 1938 to increase spectral resolution of the spectrograph while minimizing light losses by “slicing” the star image into a spot of less width and greater length. However, slicing the image creates a multiple-peak order in the cross-dispersion direction, which ultimately impacts modeling of the extracted spectrum. Here we present the design of a modified Bowen-Walraven type image slicer that re-images the sliced spot onto a rectangular optical fiber, using the exit of that fiber to feed a spectrograph. Such a fiber preserves the narrow width in the image plane while creating stable illumination in the pupil plane. The fiber also provides good scrambling of the incoming light. Scrambling refers to a fiber’s ability to produce an output beam independent of input. This is of particular importance for precise radial velocities, as fiber scramblers help to decouple the spectrograph from errors such as guiding, focusing or seeing changes; thus improving the spectrograph stability. The resulting pseudo-slit is half the original slit width, doubling the spectral resolution while eliminating losses associated with a narrow slit. Such a design could be implemented on many current high resolution spectrographs. We acknowledge the support of the Planetary Society, NSF and NASA.

  4. LRS2: the new facility low resolution integral field spectrograph for the Hobby-Eberly telescope

    NASA Astrophysics Data System (ADS)

    Chonis, Taylor S.; Hill, Gary J.; Lee, Hanshin; Tuttle, Sarah E.; Vattiat, Brian L.

    2014-07-01

    The second generation Low Resolution Spectrograph (LRS2) is a new facility instrument for the Hobby-Eberly Telescope (HET). Based on the design of the Visible Integral-field Replicable Unit Spectrograph (VIRUS), which is the new flagship instrument for carrying out the HET Dark Energy Experiment (HETDEX), LRS2 provides integral field spectroscopy for a seeing-limited field of 12" x 6". For LRS2, the replicable design of VIRUS has been leveraged to gain broad wavelength coverage from 370 nm to 1.0 μm, spread between two fiber-fed dual- channel spectrographs, each of which can operate as an independent instrument. The blue spectrograph, LRS2-B, covers 370 λ (nm) <= 470 and 460 <= λ (nm) <= 700 at fixed resolving powers of R = λ/δλ ≍ 1900 and 1100, respectively, while the red spectrograph, LRS2-R, covers 650 <= λ (nm) <= 842 and 818 <= λ (nm) <= 1050 with both of its channels having R ≍ 1800. In this paper, we present a detailed description of the instrument's design in which we focus on the departures from the basic VIRUS framework. The primary modifications include the fore-optics that are used to feed the fiber integral field units at unity fill-factor, the cameras' correcting optics and detectors, and the volume phase holographic grisms. We also present a model of the instrument's sensitivity and a description of specific science cases that have driven the design of LRS2, including systematically studying the spatially resolved properties of extended Lyα blobs at 2 < z < 3. LRS2 will provide a powerful spectroscopic follow-up platform for large surveys such as HETDEX.

  5. Visualization and Analysis of Spectrograph-mode Data Products from Far Ultraviolet Scanning Imaging Sensors

    NASA Astrophysics Data System (ADS)

    Wolven, B. C.; Schaefer, R. K.; Hsieh, S. W.; Paxton, L. J.

    2009-12-01

    Far Ultraviolet Scanning Imaging Sensors such as GUVI (one of four instruments on NASA's TIMED spacecraft) and the SSUSI instruments (on the newer DMSP satellites) typically operate in "imaging mode", wherein they gather data from a large spatial area, using a scanning mirror to image locations from the top of the limb down and across the disk. In this mode, the instruments generate only limited spectral information, which is compressed on board into five spectral "colors" that capture the most aeronomically relevant emissions. Telemetry bandwidth limitations preclude the transmission of complete spectral information at each observed spatial position (>2000 spatial positions per scan, 3-4 scans per minute). These instruments can also operate in a "spectrograph mode", wherein the full spectrum observed by the instrument is preserved, but observations are made at only a single mirror scan position. Spectrograph mode operation essentially trades spatial coverage for spectral coverage within the given bandwidth constraints. Spectrograph mode data is used for calibration purposes (e.g., stellar observations on the limb, analysis of instrument performance on the disk), but also presents some unique new scientific opportunities. The recent demise of the scan motor mechanism in the GUVI instrument (still operating long after the completion of the standard mission) means that GUVI is now operating continuously in spectrograph mode. To use these data effectively, we must generate products that distill vast quantities of data into useful and usable knowledge. We examine the state of data products associated with spectrograph mode observations, their use as a replacement for earlier imaging mode products, and potential new uses for both current and future products with enhanced spectral resolution.

  6. Subsystem Imaging Performance and Modeling of the Infrared Multi-Object Spectrograph

    NASA Technical Reports Server (NTRS)

    Connelly, Joseph A.; Tveekrem, June L.; Ohl, Raymond G.; Mink, Ronald; Chambers, V. John; Mentzell, J. Eric; Greenhouse, Matthew A.; MacKenty, John W.; Krebs, Carolyn (Technical Monitor)

    2002-01-01

    The Infrared Multi-Object Spectrograph (IRMOS) is a facility instrument for the Kitt Peak National Observatory Mayall Telescope (3.8 meter). IRMOS is a near-IR (0.8 - 2.5 micron) spectrograph with low to mid resolution (R=lambda/delta, lambda = 300 - 3800). The IRMOS spectrograph produces simultaneous spectra of - 100 objects in its 2.8 x 2.0 arc-min field of view using a commercial MEMS multi-mirror array device (MMA). The IRMOS optical design consists of two imaging systems, or "stages." The focal reducer, stage one, images the focal plane of the telescope onto the MMA. The spectrograph, stage two, images the MMA onto the detector. We describe the breadboard alignment method and imaging and scattered light performance for both the focal reducer and spectrograph. This testing provides verification of the optomechanical alignment method, and a measurement of the contribution of scattered light in the system due to mirror small scale surface error. After the stage I and 2 optics are integrated with the instrument, our test results will make it possible to distinguish between scattered light from the mirrors and the MMA. Image testing will be done at four wavelengths in the visible and near-IR. A mercury-argon pencil lamp will provide spectral lines at 546.1 and 1012 nm, and a blackbody radiation source lines at 1600 and 2200 nm. A CCD camera will be used as a detector for the visible wavelengths, and an IR photodiode will be used for the IR wavelengths. We compare our data with a theoretical analysis using a commercial software package. Mirror surface error is modeled by treating each surface as a superposition of various gratings (e.g., diamond turning tool marks, features due to the impurities of Al 6061, and periodic mid-frequency errors due to drift during machining).

  7. A Compact Ring Design with Tunable Momentum Compaction

    SciTech Connect

    Sun, Y.; /SLAC

    2012-05-17

    A storage ring with tunable momentum compaction has the advantage in achieving different RMS bunch length with similar RF capacity, which is potentially useful for many applications, such as linear collider damping ring and predamping ring where injected beam has a large energy spread and a large transverse emittance. A tunable bunch length also makes the commissioning and fine tuning easier in manipulating the single bunch instabilities. In this paper, a compact ring design based on a supercell is presented, which achieves a tunable momentum compaction while maintaining a large dynamic aperture.

  8. Compact standoff Raman system for detection of homemade explosives

    NASA Astrophysics Data System (ADS)

    Misra, Anupam K.; Sharma, Shiv K.; Bates, David E.; Acosta, Tayro E.

    2010-04-01

    We present data on standoff detection of chemicals used in synthesis of homemade explosives (HME) using a compact portable standoff Raman system developed at the University of Hawaii. Data presented in this article show that good quality Raman spectra of various organic and inorganic chemicals, including hazardous chemicals such as ammonium nitrate, potassium nitrate, potassium perchlorate, sulfur, nitrobenzene, benzene, acetone, and gasoline, can be easily obtained from remote distances with a compact standoff Raman system utilizing only a regular 85 mm Nikon camera lens as collection optics. Raman spectra of various chemicals showing clear Raman fingerprints obtained from targets placed at 50 m distance in daylight with 1 to 10 second of integration time are presented in this article. A frequency-doubled mini Nd:YAG pulsed laser source (532 nm, 30 mJ/pulse, 20 Hz, pulse width 8 ns) is used in an oblique geometry to excite the target located at 50 m distance. The standoff Raman system uses a compact spectrograph of size 10 cm (length) × 8.2 cm (width) × 5.2 cm (height) with spectral coverage from 100 to 4500 cm-1 Stokes-Raman shifted from 532 nm laser excitation and is equipped with a gated thermo-electrically cooled ICCD detector. The system is capable of detecting both the target as well as the atmospheric gases before the target. Various chemicals could be easily identified through glass, plastic, and water media. Possible applications of the standoff Raman system for homeland security and environmental monitoring are discussed.

  9. Compact plasma accelerator

    NASA Technical Reports Server (NTRS)

    Foster, John E. (Inventor)

    2004-01-01

    A compact plasma accelerator having components including a cathode electron source, an anodic ionizing gas source, and a magnetic field that is cusped. The components are held by an electrically insulating body having a central axis, a top axial end, and a bottom axial end. The cusped magnetic field is formed by a cylindrical magnet having an axis of rotation that is the same as the axis of rotation of the insulating body, and magnetized with opposite poles at its two axial ends; and an annular magnet coaxially surrounding the cylindrical magnet, magnetized with opposite poles at its two axial ends such that a top axial end has a magnetic polarity that is opposite to the magnetic polarity of a top axial end of the cylindrical magnet. The ionizing gas source is a tubular plenum that has been curved into a substantially annular shape, positioned above the top axial end of the annular magnet such that the plenum is centered in a ring-shaped cusp of the magnetic field generated by the magnets. The plenum has one or more capillary-like orifices spaced around its top such that an ionizing gas supplied through the plenum is sprayed through the one or more orifices. The plenum is electrically conductive and is positively charged relative to the cathode electron source such that the plenum functions as the anode; and the cathode is positioned above and radially outward relative to the plenum.

  10. Compact vacuum insulation

    DOEpatents

    Benson, David K.; Potter, Thomas F.

    1992-01-01

    Improved compact insulation panel is provided which is comprised of two adjacent metal sheets spaced close together with a plurality of spherical, or other discretely shaped, glass or ceramic beads optimally positioned between the sheets to provide support and maintain the spacing between the metal sheets when the gases therebetween are evacuated to form a vacuum. These spherical glass beads provide the maximum support while minimizing thermal conductance. In its preferred embodiment; these two metal sheets are textured with ribs or concave protrusions in conjunction with the glass beads to maximize the structural integrity of the panels while increasing the spacing between beads, thereby reducing the number of beads and the number of thermal conduction paths. Glass or porcelain-enameled liners in combination with the glass spacers and metal sidewalls effectively decrease thermal conductivity, and variious laminates, including wood, porcelain-enameled metal, and others effectively increase the strength and insulation capabilities of the panels. Also, a metal web is provided to hold the spacers in place, and strategic grooves are shown to accommodate expansion and contraction or shaping of the panels.

  11. Compact vacuum insulation

    DOEpatents

    Benson, D.K.; Potter, T.F.

    1992-10-27

    Improved compact insulation panel is provided which is comprised of two adjacent metal sheets spaced close together with a plurality of spherical, or other discretely shaped, glass or ceramic beads optimally positioned between the sheets to provide support and maintain the spacing between the metal sheets when the gases there between are evacuated to form a vacuum. These spherical glass beads provide the maximum support while minimizing thermal conductance. In its preferred embodiment; these two metal sheets are textured with ribs or concave protrusions in conjunction with the glass beads to maximize the structural integrity of the panels while increasing the spacing between beads, thereby reducing the number of beads and the number of thermal conduction paths. Glass or porcelain-enameled liners in combination with the glass spacers and metal sidewalls effectively decrease thermal conductivity, and various laminates, including wood, porcelain-enameled metal, and others effectively increase the strength and insulation capabilities of the panels. Also, a metal web is provided to hold the spacers in place, and strategic grooves are shown to accommodate expansion and contraction or shaping of the panels. 35 figs.

  12. Compact Doppler magnetograph

    NASA Astrophysics Data System (ADS)

    Ruzmaikin, Alexander; Moynihan, Philip I.; Vaughan, Arthur H.; Cacciani, Alessandro

    1998-11-01

    We designed a low-cost flight instrument that images the full solar disk through two narrow band filters at the red nd blue 'wings' of the solar potassium absorption line. The images are produced on a 1024 X 1024 charge-coupled device with a resolution of 2 arcsec per pixel. Four filtergrams taken in a very short time at both wings in the left and right states of circular polarization are used to yield a Dopplergram and a magnetogram simultaneously. The noise-equivalent velocity associated with each pixel is less than 3 m/s. The measured signal is linearly proportional to the velocity in the range +/- 4000 m/s. The range of magnetic fields is from 3 to 3000 Gauss. The optical system of the instrument is simple and easily aligned. With a pixel size of 12 micrometers , the effective focal length is 126 cm. A Raleigh resolution limit of 4 arcsec is achieved with a 5-cm entrance apertures, providing an f/25 focal ratio. The foreoptic is a two-component telephoto lens serving to limit the overall optical length to 89 cm or less. The mass of the instrument is 14 kg. the power required is less than 30 Watts. The Compact Doppler Magnetograph can be used in space mission with severe mass and power requirements. It can also be effectively used for ground-based observations: large telescope, dome or other observatory facilities are not required.

  13. Compact Dexterous Robotic Hand

    NASA Technical Reports Server (NTRS)

    Lovchik, Christopher Scott (Inventor); Diftler, Myron A. (Inventor)

    2001-01-01

    A compact robotic hand includes a palm housing, a wrist section, and a forearm section. The palm housing supports a plurality of fingers and one or more movable palm members that cooperate with the fingers to grasp and/or release an object. Each flexible finger comprises a plurality of hingedly connected segments, including a proximal segment pivotally connected to the palm housing. The proximal finger segment includes at least one groove defining first and second cam surfaces for engagement with a cable. A plurality of lead screw assemblies each carried by the palm housing are supplied with power from a flexible shaft rotated by an actuator and output linear motion to a cable move a finger. The cable is secured within a respective groove and enables each finger to move between an opened and closed position. A decoupling assembly pivotally connected to a proximal finger segment enables a cable connected thereto to control movement of an intermediate and distal finger segment independent of movement of the proximal finger segment. The dexterous robotic hand closely resembles the function of a human hand yet is light weight and capable of grasping both heavy and light objects with a high degree of precision.

  14. Compact neutron generator

    DOEpatents

    Leung, Ka-Ngo; Lou, Tak Pui

    2005-03-22

    A compact neutron generator has at its outer circumference a toroidal shaped plasma chamber in which a tritium (or other) plasma is generated. A RF antenna is wrapped around the plasma chamber. A plurality of tritium ion beamlets are extracted through spaced extraction apertures of a plasma electrode on the inner surface of the toroidal plasma chamber and directed inwardly toward the center of neutron generator. The beamlets pass through spaced acceleration and focusing electrodes to a neutron generating target at the center of neutron generator. The target is typically made of titanium tubing. Water is flowed through the tubing for cooling. The beam can be pulsed rapidly to achieve ultrashort neutron bursts. The target may be moved rapidly up and down so that the average power deposited on the surface of the target may be kept at a reasonable level. The neutron generator can produce fast neutrons from a T-T reaction which can be used for luggage and cargo interrogation applications. A luggage or cargo inspection system has a pulsed T-T neutron generator or source at the center, surrounded by associated gamma detectors and other components for identifying explosives or other contraband.

  15. Compaction managed mirror bend achromat

    DOEpatents

    Douglas, David

    2005-10-18

    A method for controlling the momentum compaction in a beam of charged particles. The method includes a compaction-managed mirror bend achromat (CMMBA) that provides a beamline design that retains the large momentum acceptance of a conventional mirror bend achromat. The CMMBA also provides the ability to tailor the system momentum compaction spectrum as desired for specific applications. The CMMBA enables magnetostatic management of the longitudinal phase space in Energy Recovery Linacs (ERLs) thereby alleviating the need for harmonic linearization of the RF waveform.

  16. Stray-light contamination and spatial deconvolution of slit-spectrograph observations

    NASA Astrophysics Data System (ADS)

    Beck, C.; Rezaei, R.; Fabbian, D.

    2011-11-01

    Context. Stray light caused by scattering on optical surfaces and in the Earth's atmosphere degrades the spatial resolution of observations. Whereas post-facto reconstruction techniques are common for 2D imaging and spectroscopy, similar options for slit-spectrograph data are rarely applied. Aims: We study the contribution of stray light to the two channels of the POlarimetric LIttrow Spectrograph (POLIS) at 396 nm and 630 nm as an example of a slit-spectrograph instrument. We test the performance of different methods of stray-light correction and spatial deconvolution to improve the spatial resolution post-facto. Methods: We model the stray light as having two components: a spectrally dispersed component and a "parasitic" component of spectrally undispersed light caused by scattering inside the spectrograph. We used several measurements to estimate the two contributions: a) observations with a (partly) blocked field of view (FOV); b) a convolution of the FTS spectral atlas; c) imaging of the spider mounting in the pupil plane; d) umbral profiles; and e) spurious polarization signal in telluric spectral lines. The measurements with a partly blocked FOV in the focal plane allowed us to estimate the spatial point spread function (PSF) of POLIS and the main spectrograph of the German Vacuum Tower Telescope (VTT). We then used the obtained PSF for a deconvolution of both spectroscopic and spectropolarimetric data and investigated the effect on the spectra. Results: The parasitic contribution can be directly and accurately determined for POLIS, amounting to about 5% (0.3%) of the (continuum) intensity at 396 nm (630 nm). The spectrally dispersed stray light is less accessible because of its many contributing sources. We estimate a lower limit of about 10% across the full FOV for the dispersed stray light from umbral profiles. In quiet Sun regions, the stray-light level from the close surroundings (d < 2'') of a given spatial point is about 20%. The stray light reduces

  17. Compact, Reliable EEPROM Controller

    NASA Technical Reports Server (NTRS)

    Katz, Richard; Kleyner, Igor

    2010-01-01

    A compact, reliable controller for an electrically erasable, programmable read-only memory (EEPROM) has been developed specifically for a space-flight application. The design may be adaptable to other applications in which there are requirements for reliability in general and, in particular, for prevention of inadvertent writing of data in EEPROM cells. Inadvertent writes pose risks of loss of reliability in the original space-flight application and could pose such risks in other applications. Prior EEPROM controllers are large and complex and do not provide all reasonable protections (in many cases, few or no protections) against inadvertent writes. In contrast, the present controller provides several layers of protection against inadvertent writes. The controller also incorporates a write-time monitor, enabling determination of trends in the performance of an EEPROM through all phases of testing. The controller has been designed as an integral subsystem of a system that includes not only the controller and the controlled EEPROM aboard a spacecraft but also computers in a ground control station, relatively simple onboard support circuitry, and an onboard communication subsystem that utilizes the MIL-STD-1553B protocol. (MIL-STD-1553B is a military standard that encompasses a method of communication and electrical-interface requirements for digital electronic subsystems connected to a data bus. MIL-STD- 1553B is commonly used in defense and space applications.) The intent was to both maximize reliability while minimizing the size and complexity of onboard circuitry. In operation, control of the EEPROM is effected via the ground computers, the MIL-STD-1553B communication subsystem, and the onboard support circuitry, all of which, in combination, provide the multiple layers of protection against inadvertent writes. There is no controller software, unlike in many prior EEPROM controllers; software can be a major contributor to unreliability, particularly in fault

  18. Compact dc link

    SciTech Connect

    Flairty, C. )

    1991-10-01

    The EPRI Compact Substation Project (a HVDC Converter Station) was developed, designed, and constructed per EPRI Agreement RP213. In December 1983, the converter station operated at its rating (100 MW power transmission and 300 kV dc bias plus 100 kV operating voltage). From January to May 1984, the converter station operated at various power transmission levels. Operation was intermittent due to a randomly occurring voltage breakdown. The voltage breakdown was isolated to the steel tanks containing the thyristor valves in an SF{sub 6} environment. The type of insulators stressed within the valve tanks were: (1) the epoxy cone shape insulators providing an interface to the bus entering the valve tank; (2) epoxy fiberglass hydraulic columns for the flow of the R113 refrigerant to and from the thyristor valves; and (3) the epoxy fiberglass support columns supporting the thyristor valves from the floor of the valve tank. The cause of the randomly occurring breakdown was investigated and determined to be the epoxy fiberglass support columns. The random dielectric breakdowns were due to excessive voltage gradients existing at the epoxy fiberglass support columns. This probably was caused by the misplacement of an internal insert within the column with respect to an external shield on the column. The cost and time to retrofit the support columns outweighed the benefits expected from resuming the project. Consequently, work was terminated and the equipment disassembled. Examination of the epoxy fiberglass support columns revealed several arcing tracks along the inside surface confirming the earlier hypothesis. 53 figs., 32 tabs.

  19. Compact Grism Spectrometer

    NASA Astrophysics Data System (ADS)

    Teare, S. W.

    2003-05-01

    Many observatories and instrument builders are retrofitting visible and near-infrared spectrometers into their existing imaging cameras. Camera designs that reimage the focal plane and have the optical filters located in a pseudo collimated beam are ideal candidates for the addition of a spectrometer. One device commonly used as the dispersing element for such spectrometers is a grism. The traditional grism is constructed from a prism that has had a diffraction grating applied on one surface. The objective of such a design is to use the prism wedge angle to select the desired "in-line" or "zero-deviation" wavelength that passes through on axis. The grating on the surface of the prism provides much of the dispersion for the spectrometer. A grism can also be used in a "constant-dispersion" design which provides an almost linear spatial scale across the spectrum. In this paper we provide an overview of the development of a grism spectrometer for use in a near infrared camera and demonstrate that a compact grism spectrometer can be developed on a very modest budget that can be afforded at almost any facility. The grism design was prototyped using visible light and then a final device was constructed which provides partial coverage in the near infrared I, J, H and K astronomical bands using the appropriate band pass filter for order sorting. The near infrared grism presented here provides a spectral resolution of about 650 and velocity resolution of about 450 km/s. The design of this grism relied on a computer code called Xspect, developed by the author, to determine the various critical parameters of the grism. This work was supported by a small equipment grant from NASA and administered by the AAS.

  20. Compact Holographic Data Storage

    NASA Technical Reports Server (NTRS)

    Chao, T. H.; Reyes, G. F.; Zhou, H.

    2001-01-01

    NASA's future missions would require massive high-speed onboard data storage capability to Space Science missions. For Space Science, such as the Europa Lander mission, the onboard data storage requirements would be focused on maximizing the spacecraft's ability to survive fault conditions (i.e., no loss in stored science data when spacecraft enters the 'safe mode') and autonomously recover from them during NASA's long-life and deep space missions. This would require the development of non-volatile memory. In order to survive in the stringent environment during space exploration missions, onboard memory requirements would also include: (1) survive a high radiation environment (1 Mrad), (2) operate effectively and efficiently for a very long time (10 years), and (3) sustain at least a billion write cycles. Therefore, memory technologies requirements of NASA's Earth Science and Space Science missions are large capacity, non-volatility, high-transfer rate, high radiation resistance, high storage density, and high power efficiency. JPL, under current sponsorship from NASA Space Science and Earth Science Programs, is developing a high-density, nonvolatile and rad-hard Compact Holographic Data Storage (CHDS) system to enable large-capacity, high-speed, low power consumption, and read/write of data in a space environment. The entire read/write operation will be controlled with electrooptic mechanism without any moving parts. This CHDS will consist of laser diodes, photorefractive crystal, spatial light modulator, photodetector array, and I/O electronic interface. In operation, pages of information would be recorded and retrieved with random access and high-speed. The nonvolatile, rad-hard characteristics of the holographic memory will provide a revolutionary memory technology meeting the high radiation challenge facing the Europa Lander mission. Additional information is contained in the original extended abstract.

  1. Module-type flat-field grazing-incidence spectrographs for large Tokamak (JT-60) plasma diagnosis

    NASA Astrophysics Data System (ADS)

    Nagata, Hiroshi; Kihara, Naoto; Yamashita, Takaji; Sugie, Tatsuo; Kubo, Hirotaka; Shiho, Makoto

    1990-09-01

    Module-type flat-field grazing-incidence spectrographs with holographic gratings and multichannel detectors for large TOKAMAK (JT-60) plasma diagnosis are developed. The spectrographs cover the different wavelength regions from 0.5-122 nm, and are set to measure impurity lines in the plasma every 20 ms with space resolution of 7 cm. The flat-field imaging properties with designed wavelength resolution were confirmed, and results of tokamak plasma measurements proved the value of these spectrographs for plasma diagnosis.

  2. A Compact Beam Measurement Setup

    NASA Astrophysics Data System (ADS)

    Graf, Urs U.

    2016-08-01

    We present the design of a compact measurement device to determine the position of a beam in a radio optical setup. The unit is used to align the Terahertz optics of the GREAT instrument on the airborne astronomical observatory SOFIA.

  3. An isolated compact galaxy triplet

    NASA Astrophysics Data System (ADS)

    Feng, Shuai; Shao, Zheng-Yi; Shen, Shi-Yin; Argudo-Fernández, Maria; Wu, Hong; Lam, Man-I.; Yang, Ming; Yuan, Fang-Ting

    2016-05-01

    We report the discovery of an isolated compact galaxy triplet SDSS J084843.45+164417.3, which is first detected by the LAMOST spectral survey and then confirmed by a spectroscopic observation of the BFOSC mounted on the 2.16 meter telescope located at Xinglong Station, which is administered by National Astronomical Observatories, Chinese Academy of Sciences. It is found that this triplet is an isolated and extremely compact system, which has an aligned configuration and very small radial velocity dispersion. The member galaxies have similar colors and show marginal star formation activities. These results support the opinion that the compact triplets are well-evolved systems rather than hierarchically forming structures. This serendipitous discovery reveals the limitations of fiber spectral redshift surveys in studying such a compact system, and demonstrates the necessity of additional observations to complete the current redshift sample.

  4. A compact rotary vane attenuator

    NASA Technical Reports Server (NTRS)

    Nixon, D. L.; Otosh, T. Y.; Stelzried, C. T.

    1969-01-01

    Rotary vane attenuator, when used as a front end attenuator, introduces an insertion loss that is proportional to the angle of rotation. New technique allows the construction of a shortened compact unit suitable for most installations.

  5. What Is Business's Social Compact?

    ERIC Educational Resources Information Center

    Avishai, Bernard

    1994-01-01

    Under the "new" social compact, businesses must focus on continuous learning and thus have both an obligation to support teaching and an opportunity to profit from it. Learning organizations must also be teaching organizations. (SK)

  6. A Compact Beam Measurement Setup

    NASA Astrophysics Data System (ADS)

    Graf, Urs U.

    2016-03-01

    We present the design of a compact measurement device to determine the position of a beam in a radio optical setup. The unit is used to align the Terahertz optics of the GREAT instrument on the airborne astronomical observatory SOFIA.

  7. MESOSCALE SIMULATIONS OF POWDER COMPACTION

    SciTech Connect

    Lomov, Ilya; Fujino, Don; Antoun, Tarabay; Liu, Benjamin

    2009-12-28

    Mesoscale 3D simulations of shock compaction of metal and ceramic powders have been performed with an Eulerian hydrocode GEODYN. The approach was validated by simulating a well-characterized shock compaction experiment of a porous ductile metal. Simulation results using the Steinberg material model and handbook values for solid 2024 aluminum showed good agreement with experimental compaction curves and wave profiles. Brittle ceramic materials are not as well studied as metals, so a simple material model for solid ceramic (tungsten carbide) has been calibrated to match experimental compaction curves. Direct simulations of gas gun experiments with ceramic powders have been performed and showed good agreement with experimental data. The numerical shock wave profile has same character and thickness as that measured experimentally using VISAR. The numerical results show reshock states above the single-shock Hugoniot line as observed in experiments. We found that for good quantitative agreement with experiments 3D simulations are essential.

  8. Mesoscale Simulations of Powder Compaction

    NASA Astrophysics Data System (ADS)

    Lomov, Ilya.; Fujino, Don; Antoun, Tarabay; Liu, Benjamin

    2009-12-01

    Mesoscale 3D simulations of shock compaction of metal and ceramic powders have been performed with an Eulerian hydrocode GEODYN. The approach was validated by simulating a well-characterized shock compaction experiment of a porous ductile metal. Simulation results using the Steinberg material model and handbook values for solid 2024 aluminum showed good agreement with experimental compaction curves and wave profiles. Brittle ceramic materials are not as well studied as metals, so a simple material model for solid ceramic (tungsten carbide) has been calibrated to match experimental compaction curves. Direct simulations of gas gun experiments with ceramic powders have been performed and showed good agreement with experimental data. The numerical shock wave profile has same character and thickness as that measured experimentally using VISAR. The numerical results show reshock states above the single-shock Hugoniot line as observed in experiments. We found that for good quantitative agreement with experiments 3D simulations are essential.

  9. Compact Ho:YLF Laser

    NASA Technical Reports Server (NTRS)

    Hemmati, H.

    1988-01-01

    Longitudinal pumping by laser diodes increases efficiency. Improved holmium:yttrium lithium fluoride laser radiates as much as 56 mW of power at wavelength of 2.1 micrometer. New Ho:YLF laser more compact and efficient than older, more powerful devices of this type. Compact, efficient Ho:YLF laser based on recent successes in use of diode lasers to pump other types of solid-state lasers.

  10. New design approaches for a very high resolution spectrograph for the combined focus of the VLT

    NASA Astrophysics Data System (ADS)

    Spanò, Paolo; Delabre, Bernard; Dekker, Hans; Avila, Gerardo

    2008-07-01

    To achieve very-high spectral resolutions (R>100,000) with large telescopes (D>8m) new optical solutions have been investigated in the context of the ESPRESSO project for the VLT, starting from the initial design of CODEX for the E-ELT. ESPRESSO is a high-efficiency, high-stability, high-resolution visible spectrograph for the combined Coude focus of the VLT. Among these new solutions, we can mention: free-form optics, used to design an all-mirror anamorphic pupil slicer, large mosaic echelle grating, slanted VPH gratings, super-corrected atmospheric dispersion corrector. All these solutions have been usefully applied to design the spectrograph for ESPRESSO, and its Coude relay system.

  11. Using an integral-field unit spectrograph to study radical species in cometary coma

    NASA Astrophysics Data System (ADS)

    Lewis, Benjamin; Pierce, Donna M.; Vaughan, Charles M.; Cochran, Anita

    2015-01-01

    We have observed several comets using an integral-field unit spectrograph (the George and Cynthia Mitchell Spectrograph) on the 2.7m Harlan J. Smith telescope at McDonald Observatory. Full-coma spectroscopic images were obtained for various radical species (C2, C3, CN, NH2). Various coma enhancements were used to identify and characterize coma morphological features. The azimuthal average profiles and the Haser model were used to determine production rates and possible parent molecules. Here, we present the work completed to date, and we compare our results to other comet taxonomic surveys. This work was funded by the National Science Foundation Graduate K-12 (GK-12) STEM Fellows program (Award No. DGE-0947419), NASA's Planetary Atmospheres program (Award No. NNX14AH18G), and the Fund for Astrophysical Research, Inc.

  12. Using an integral-field unit spectrograph to study radical species in cometary coma

    NASA Astrophysics Data System (ADS)

    Lewis, Benjamin; Pierce, Donna; Cochran, Anita; Vaughan, Charles

    2014-11-01

    We have observed several comets using an integral-field unit spectrograph (the George and Cynthia Mitchell Spectrograph) on the 2.7m Harlan J. Smith telescope at McDonald Observatory. Full-coma spectroscopic images were obtained for various radical species (C2, C3, CN, NH2). Various coma enhancements were used to identify and characterize coma morphological features. The azimuthal average profiles and the Haser model were used to determine production rates and possible parent molecules. Here, we present the work completed to date, and we compare our results to other comet taxonomic surveys. This work was funded by the National Science Foundation Graduate K-12 (GK-12) STEM Fellows program (Award No. DGE-0947419), NASA’s Planetary Atmospheres program (Award No. NNX14AH18G), and the Fund for Astrophysical Research, Inc.

  13. Optical Design with Aspherical Gratings - the Example of the Uv-Prim Spectrograph

    NASA Astrophysics Data System (ADS)

    Lemaitre, G.

    1981-11-01

    Aspherical diffraction gratings have been produced by the elastic relaxation method. These gratings lead to more nearly ideal mountings from the standpoints of a small number of surfaces, of a wide field and of a fast aperture ratio. The UV-PRIM spectrograph is the first instrument of this type to have been constructed. Resumé en français. Des réseaux asphériques ont été obtenus en utilisant la méthode des relaxations élastiques. Ces réseaux de diffraction conduisent à un montage très performant du point de vue du faible nombre de surfaces optiques, d'un grand champ et d'un rapport d'ouverture élevé. Le spectrographe UV-PRIM est le premier instrument de ce type à avoir été construit.

  14. Component Radiometric Calibrations of the EUV Normal-Incidence Spectrograph (EUNIS)

    NASA Astrophysics Data System (ADS)

    Thomas, R. J.; Rabin, D. M.

    2005-12-01

    The EUV Normal-Incidence Spectrograph (EUNIS) is a sounding rocket experiment that will investigate the energetics of the solar corona and hotter transition region through high-resolution imaging spectroscopy with a rapid (2 s) cadence. EUNIS features independent optical systems to record spatially co-aligned spectra simultaneously over its two bandpasses of 170--205 and 300--370 Å. All the components in the detection chain have been characterized, including multilayer telescope mirrors, lithographic slits, multilayer diffraction gratings, microchannel-plate intensifiers, and active-pixel sensors. The results demonstrate that EUNIS is the most sensitive solar EUV spectrograph in existence. Its first flight is scheduled for 2005 November. EUNIS is supported by NASA RTOP 432-03-31.

  15. Rocket studies of solar corona and transition region. [X-Ray spectrometer/spectrograph telescope

    NASA Technical Reports Server (NTRS)

    Acton, L. W.; Bruner, E. C., Jr.; Brown, W. A.; Nobles, R. A.

    1979-01-01

    The XSST (X-Ray Spectrometer/Spectrograph Telescope) rocket payload launched by a Nike Boosted Black Brant was designed to provide high spectral resolution coronal soft X-ray line information on a spectrographic plate, as well as time resolved photo-electric records of pre-selected lines and spectral regions. This spectral data is obtained from a 1 x 10 arc second solar region defined by the paraboloidal telescope of the XSST. The transition region camera provided full disc images in selected spectral intervals originating in lower temperature zones than the emitting regions accessible to the XSST. A H-alpha camera system allowed referencing the measurements to the chromospheric temperatures and altitudes. Payload flight and recovery information is provided along with X-ray photoelectric and UV flight data, transition camera results and a summary of the anomalies encountered. Instrument mechanical stability and spectrometer pointing direction are also examined.

  16. Silicon immersion grating spectrograph design for the NASA Infrared Telescope Facility

    NASA Astrophysics Data System (ADS)

    Tokunaga, A. T.; Bond, T.; Jaffe, D. T.; Mumma, M. J.; Rayner, J. T.; Tollestrup, E. V.; Warren, D. W.

    2008-07-01

    We present a conceptual design for an innovative infrared cross-dispersed spectrograph for the NASA Infrared Telescope Facility (IRTF) at Mauna Kea. This facility-class instrument will provide a resolving power of up to 80,000 at 1.2-2.5 μm and 67,000 at 3-5 μm with a minimum slit width of 0.25". The instrument employs a silicon immersion grating in order to reduce the size of the instrument. The design incorporates a 2048×2048 infrared array for the spectrograph and an infrared slit viewer. The optical design is optimized for the thermal infrared (2.8-5.5 μm).

  17. Design and performance of a F/#-conversion microlens for prime focus spectrograph at Subaru Telescope

    NASA Astrophysics Data System (ADS)

    Takato, Naruhisa; Tanaka, Yoko; Gunn, James E.; Tamura, Naoyuki; Shimono, Atsushi; Sugai, Hajime; Karoji, Hiroshi; Ueda, Akitoshi; Waseda, Kouichi; Kimura, Masahiko; Ohyama, Youichi

    2014-07-01

    The PFS is a multi-object spectrograph fed by 2394 fibers at the prime focus of Subaru telescope. Since the F/# at the prime focus is too fast for the spectrograph, we designed a small concave-plano negative lens to be attached to the tip of each fiber that converts the telescope beam (F/2.2) to F/2.8. We optimized the lens to maximize the number of rays that can be confined inside F/2.8 while maintaining a 1.28 magnification. The microlenses are manufactured by glass molding, and an ultra-broadband AR coating (<1.5% for λ = 0.38 - 1.26μm) will be applied to the front surface.

  18. Detectors for the James Webb Space Telescope Near-Infrared Spectrograph

    NASA Technical Reports Server (NTRS)

    Rauscher, Bernard J.; Figer, Donald F.; Regan, Michael W.; Boeker, Torsten; Garnett, James; Hill, Robert J.; Bagnasco, Georgio; Balleza, Jesus; Barney, Richard; Bergeron, Louis E.

    2004-01-01

    The Near-Infrared Spectrograph (NIRSpec) is the James Webb Space Telescope's primary near-infrared spectrograph. NASA is providing the NIRSpec detector subsystem, which consists of the focal plane array, focal plane electronics, cable harnesses, and software. The focal plane array comprises two closely-butted lambda (sub co) approximately 5 micrometer Rockwell HAWAII- 2RG sensor chip assemblies. After briefly describing the NIRSpec instrument, we summarize some of the driving requirements for the detector subsystem, discuss the baseline architecture (and alternatives), and presents some recent detector test results including a description of a newly identified noise component that we have found in some archival JWST test data. We dub this new noise component, which appears to be similar to classical two-state popcorn noise in many aspects, "popcorn mesa noise." We close with the current status of the detector subsystem development effort.

  19. The Colorado High-Resolution Echelle Stellar Spectrograph (CHESS) Design and Status

    NASA Astrophysics Data System (ADS)

    Beasley, Matthew

    I present a new far-ultraviolet echelle spectrograph, which will provide resolving power greater than any currently existing far-ultraviolet instrument. We are using new gratings, detectors, and coatings that allow substantial advances in performance. I will present the current status of the design, and discuss known challenges and our plans to resolve them. While the design purpose of this instrument is for observations of nearby hot stars, the technologies we incorporate will allow for advances relevant to observation subjects from protoplanetary disks to the intergalactic medium. Incorporating such a spectrograph into a future, long-duration mission will make new high-quality observations possible and enhance our understanding of astrophysical plasmas.

  20. An Integral-Field Spectrograph for a Terrestrial Planet Finding Mission

    NASA Technical Reports Server (NTRS)

    Heap, Sara R.

    2011-01-01

    We describe a conceptual design for an integral field spectrograph for characterizing exoplanets that we developed for NASA's Terrestrial Planet Finder Coronagraph (TPF-C), although it is equally applicable to an external-occulter mission. The spectrograph fulfills all four scientific objectives of a terrestrial planet finding mission by: (1) Spectrally characterizing the atmospheres of detected planets in search of signatures of habitability or even biological activity; (2) Directly detecting terrestrial planets in the habitable zone around nearby stars; (3) Studying all constituents of a planetary system including terrestrial and giant planets, gas and dust around sun-like stars of different ages and metallicities; (4) Enabling simultaneous, high-spatial-resolution, spectroscopy of all astrophysical sources regardless of central source luminosity, such as AGN's, proplyds, etc.

  1. An integral field spectrograph design concept for the terrestrial planet finder coronagraph

    NASA Astrophysics Data System (ADS)

    Woodgate, Bruce; Mentzell, Eric; Hilton, George; Lindler, Don

    2006-06-01

    An integral field spectrograph following the TPF coronagraph can provide the required spectral resolving power R ˜ 70 with spatial resolution at the telescope diffraction limit, and covering the coronagraphic dark hole. This allows spectra to be obtained of all planets around the star simultaneously, spectra of disks, measurement of residual speckles for subtraction, and insensitivity to roll control and alignment. Short spectra and the many spatial elements required are most easily implemented using a microlens array at the entrance to a prism spectrograph. To minimize the size of the special photon-counting CCD detectors required, a high filling factor of detector pixel usage is desired. This can be accomplished by using a crossed cylindrical microlens array to create virtual slits at the focus of each lenslet. The lenslets must be illuminated by a highly asymmetric image scale, for which we use cylindrical mirrors to magnify the image in one direction while de-magnifying in the orthogonal direction.

  2. Detectors for the James Webb Space Telescope near-infrared spectrograph

    NASA Astrophysics Data System (ADS)

    Rauscher, Bernard J.; Figer, Donald F.; Regan, Michael W.; Boeker, Torsten; Garnett, James; Hill, Robert J.; Bagnasco, Giorgio; Balleza, Jesus; Barney, Richard; Bergeron, Louis E.; Brambora, Clifford; Connelly, Joe; Derro, Rebecca; DiPirro, Michael J.; Doria-Warner, Christina; Ericsson, Aprille; Glazer, Stuart D.; Greene, Charles; Hall, Donald N.; Jacobson, Shane; Jakobsen, Peter; Johnson, Eric; Johnson, Scott D.; Krebs, Carolyn; Krebs, Danny J.; Lambros, Scott D.; Likins, Blake; Manthripragada, Sridhar; Martineau, Robert J.; Morse, Ernie C.; Moseley, Samuel H.; Mott, D. Brent; Muench, Theo; Park, Hongwoo; Parker, Susan; Polidan, Elizabeth J.; Rashford, Robert; Shakoorzadeh, Kamdin; Sharma, Rajeev; Strada, Paolo; Waczynski, Augustyn; Wen, Yiting; Wong, Selmer; Yagelowich, John; Zuray, Monica

    2004-10-01

    The Near-Infrared Spectrograph (NIRSpec) is the James Webb Space Telescope"s primary near-infrared spectrograph. NASA is providing the NIRSpec detector subsystem, which consists of the focal plane array, focal plane electronics, cable harnesses, and software. The focal plane array comprises two closely-butted λco ~ 5 μm Rockwell HAWAII-2RG sensor chip assemblies. After briefly describing the NIRSpec instrument, we summarize some of the driving requirements for the detector subsystem, discuss the baseline architecture (and alternatives), and presents some recent detector test results including a description of a newly identified noise component that we have found in some archival JWST test data. We dub this new noise component, which appears to be similar to classical two-state popcorn noise in many aspects, "popcorn mesa noise." We close with the current status of the detector subsystem development effort.

  3. Designing the optimal semi-warm NIR spectrograph for SALT via detailed thermal analysis

    NASA Astrophysics Data System (ADS)

    Wolf, Marsha J.; Sheinis, Andrew I.; Mulligan, Mark P.; Wong, Jeffrey P.; Rogers, Allen

    2008-07-01

    The near infrared (NIR) upgrade to the Robert Stobie Spectrograph (RSS) on the Southern African Large Telescope (SALT), RSS/NIR, extends the spectral coverage of all modes of the optical spectrograph. The RSS/NIR is a low to medium resolution spectrograph with broadband, spectropolarimetric, and Fabry-Perot imaging capabilities. The optical and NIR arms can be used simultaneously to extend spectral coverage from 3200 Å to approximately 1.6 μm. Both arms utilize high efficiency volume phase holographic gratings via articulating gratings and cameras. The NIR camera incorporates a HAWAII-2RG detector with an Epps optical design consisting of 6 spherical elements and providing subpixel rms image sizes of 7.5 +/- 1.0 μm over all wavelengths and field angles. The NIR spectrograph is semi-warm, sharing a common slit plane and partial collimator with the optical arm. A pre-dewar, cooled to below ambient temperature, houses the final NIR collimator optic, the grating/Fabry-Perot etalon, the polarizing beam splitter, and the first three camera optics. The last three camera elements, blocking filters, and detector are housed in a cryogenically cooled dewar. The semi-warm design concept has long been proposed as an economical way to extend optical instruments into the NIR, however, success has been very limited. A major portion of our design effort entails a detailed thermal analysis using non-sequential ray tracing to interactively guide the mechanical design and determine a truly realizable long wavelength cutoff over which astronomical observations will be sky-limited. In this paper we describe our thermal analysis, design concepts for the staged cooling scheme, and results to be incorporated into the overall mechanical design and baffling.

  4. Variability in the vacuum-ultraviolet transmittance of magnesium fluoride windows. [for Space Telescope Imaging Spectrograph

    NASA Technical Reports Server (NTRS)

    Herzig, Howard; Fleetwood, Charles M., Jr.; Toft, Albert R.

    1992-01-01

    Sample window materials tested during the development of a domed magnesium fluoride detector window for the Hubble Space Telescope's Imaging Spectrograph are noted to exhibit wide variability in VUV transmittance; a test program was accordingly instituted to maximize a prototype domed window's transmittance. It is found that VUV transmittance can be maximized if the boule from which the window is fashioned is sufficiently large to allow such a component to be cut from the purest available portion of the boule.

  5. Research on a novel high gain model for dispersive spectrographic systems

    NASA Astrophysics Data System (ADS)

    Cheng, Liang; Ye, Zi; Gong, Xingzhi; Yu, Feihong

    2008-03-01

    Traditional dispersive spectrographic systems usually base on slit imaging. The entrance slit can ensure a remarkable spectral resolution but a loss of system throughput and vice versa, thus this kind of instruments can't achieve Jacquinot advantage and Fellgett advantage simultaneously and statically. To derive a high gain model for the stationary dispersive systems with these two advantages, traditional single-slit and the multi-slit spectrographic systems were studied. A method for single channel spectrum abstraction in a multi-slit spectrographic system was derived. This method demonstrates that if each individual slit in a multi-slit system possesses a transformation form of orthogonal independent column codes, the spectrum of each individual slit can be abstracted from superposed spectrum, spectral resolution of equivalent single-slit system is obtained and the system achieves dual advantages. This high gain computational system model is applicable for almost all kinds of existing dispersive spectrographic systems. Furthermore individual coded slits can be integrated as a coded aperture to increase system's integration level and reduce off-axis aberration. Based on the derivation of theoretical model, two kinds of coding forms' mathematical models were studied. To verify the derived theory, a testing system with a specially designed flat-field holographic concave grating and a coded aperture of order 16 Hadamard matrix form was set up. The experiment indicated that although optical aberration and other system noise were involved, this high gain system model could still achieve a high spectral resolution of 0.4nm as single-slit system, while remarkable system etendue (8X) and SNR (4X) were also obtained, which proved the correctness of the theoretical derivation.

  6. ELODIE & SOPHIE spectrographs: 20 years of continuous improvements in radial velocities

    NASA Astrophysics Data System (ADS)

    Bouchy, F.

    2015-10-01

    From the first light of ELODIE spectrograph in 1993 up to the recent upgrade of SOPHIE, the radial-velocity precision was improved by an order of magnitude. The different steps of instrumental refinement are described and their impact on the detection and characterization of giant exoplanets are highlighted. Synergies of these two instruments with other detection technics like photometric transit and astrometry are presented with a special focus on the incoming space missions GAIA, CHEOPS, TESS and PLATO.

  7. Emission spectrographic determination of barium in sea water using a cation exchange concentration procedure

    USGS Publications Warehouse

    Szabo, B. J.; Joensuu, O.

    1967-01-01

    A concentration technique employing Dowex 50W cation exchange resin is described for the determination of barium in sea water. The separated barium is precipitated as fluoride together with calcium and strontium and measured by emission spectrographic analysis. The vertical distribution of barium in sea water has been measured in the Caribbean Sea and the Atlantic Ocean. The barium content varied between 7 and 23 ??g. per liter; in two profiles, the lowest concentrations were at a depth of about 1000 meters.

  8. [Transmission grating spectrograph for soft X-ray spectrum measurements with a pre-optics].

    PubMed

    Wang, Z; Tian, Z; Chen, B; Wang, Z; Gao, J; Tian, X; Chen, Z; Fan, P; Chen, X

    1999-12-01

    A novel diffraction spectroscopic instrument consisting of a large area transmission grating and a grazing-incidence pre-optics comprising of a toroidal mirror, a slit and a cylindrical mirror has been implemented. A nearly perfect stigmatism and a medium spectral resolution are due to the separation of the focusing and dispersing function. The experimental results show that it is possible to construct large area transmission grating spectrograph with high collecting efficiency and good spatial resolution. PMID:15822323

  9. HETDEX: Developing the HET's Second Generation Low Resolution Spectrograph for Probing Lyman-alpha Emitting Galaxies

    NASA Astrophysics Data System (ADS)

    Chonis, Taylor S.; Hill, G. J.; Lee, H.; Tuttle, S. E.; Vattiat, B. L.; Gebhardt, K.; Finkelstein, S. L.; Adams, J. J.; HETDEX Collaboration

    2012-01-01

    HETDEX will map the power spectrum of 0.8 million blindly discovered Lyman-alpha Emitting Galaxies (LAE) using a revolutionary new array of massively replicated fiber-fed spectrographs dubbed the Visible Integral-Field Replicable Unit Spectrograph (VIRUS). In the era of the Hobby-Eberly Telescope wide-field upgrade and VIRUS, the current Low Resolution Spectrograph (LRS) must be replaced with a fiber instrument. We discuss the development of the second generation LRS (LRS2), which is a multi-channel instrument based on the VIRUS design. In its current design phase, it is fed by a 287 fiber microlens coupled integral field unit that covers 7” x 12” with 0.62” resolution. The instrument covers 3720 Å to 4700 Å at R ≈ 1900 and 4600 Å to 7000 Å at R ≈1200. With the purpose of making the instrument ideal for follow-up observations of LAE in the HETDEX survey, we discuss the science drivers for selecting the instrument's spectral resolution. We test the utility of the instrument and pilot a future study with LRS2 by presenting R ≈ 2000 spectra taken with the VIRUS prototype spectrograph (VIRUS-P) in a high-resolution mode at the McDonald Observatory Harlan J. Smith 2.7 m telescope. These LAE were originally discovered in the HETDEX Pilot Survey and their Lyman-alpha line profiles are constrained by near-infrared observations of rest-frame optical emission lines that set the systemic redshift of the galaxies. We discuss the velocity offsets of the Lyman-alpha line from the systemic line center and compare the line profiles to theoretical predictions and to similar observations for Lyman-break galaxies. Our observations provide an example of how LRS2 can be used to probe Lyman-alpha emission in 2 < z < 3 star forming galaxies.

  10. A Prototype Fringing Spectrograph for Sensitive Extra-solar Planet Searches and Astroseismology studies

    NASA Astrophysics Data System (ADS)

    Erskine, D.; Ge, J.

    1999-05-01

    We have developed a prototype fringing spectrograph optimized for sensitive stellar radial velocity measurements, aimed at detecting small extra-solar planet velocity perturbation and stellar seismology on an amplitude of ~ 1 m s(-1) or less. It is a combination of an angle-independent interferometer and a high throughput intermediate resolution spectrograph. The interferometer is used for measuring phase shifts caused by radial velocity variations of star light, while the spectrograph is applied for dispersing broad-band white fringes into different color channels to increase fringe visibility for precision phase measurements. A much simplified instrument response function (PSF), determined only by phase, amplitude and offset, compared to much more complicated ones in conventional echelle spectrographs, provides unprecedented sensitivity for radial velocity measurements. Preliminary lab-based experiments with this prototype instrument demonstrate 0.7 m s(-1) accuracy for short term radial velocity measurements. The zero point drift over 11 days was within 4 m s(-1) and may be due to the lack of interferometer stabilization during these runs. Stabilization is now being implemented through a close-loop electronics. This is expected to improve long term velocity measurement accuracy and make the instrument ready for first-light stellar observations. The instrument is also being tested with sunlight. The diurnal velocity variation caused by the Earth's rotation has been observed. Work to measure solar P-mode 5 minute oscillations is underway. This work is supported by the LLNL Laboratory Directed Research and Development (LDRD) grant through track 98-ERD-054.

  11. Ten-fold spectral resolution boosting using TEDI at the Mt. Palomar NIR Triplespec spectrograph

    NASA Astrophysics Data System (ADS)

    Erskine, David J.; Edelstein, J.; Muirhead, P.; Muterspaugh, M.; Covey, K.; Mondo, D.; Vanderburg, A.; Andelson, P.; Kimber, D.; Sirk, M.; Lloyd, J.

    2011-09-01

    An optical technique called "interferometric spectral reconstruction" (ISR) is capable of increasing a spectrograph's resolution and stability by large factors, well beyond its classical limits. We have demonstrated a 6- to 11-fold increase in the Triplespec effective spectral resolution (R=2,700) to achieve R=16,000 at 4100 cm-1to 30,000 at 9600 cm-1 by applying special Fourier processing to a series of exposures with different delays (optical path differences) taken with the TEDI interferometer and the near-infrared Triplespec spectrograph at the Mt. Palomar Observatory 200 inch telescope. The TEDI is an externally dispersed interferometer (EDI) used for Doppler radial velocity measurements on M-stars, and now also used for ISR. The resolution improvement is observed in both stellar and telluric features simultaneously over the entire spectrograph bandwidth (0.9-2.45 μm). By expanding the delay series, we anticipate achieving resolutions of R=45,000 or more. Since the delay is not continuously scanned, the technique is advantageous for measuring time-variable phenomena or in varying conditions (e.g. planetary fly-bys). The photon limited signal to noise ratio can be 100 times better than a classic Fourier Transform Spectrometer (FTS) due to the benefit of dispersion.

  12. Development of micro image slicer of integral field unit for spaceborne solar spectrograph

    NASA Astrophysics Data System (ADS)

    Suematsu, Y.; Sukegawa, T.; Okura, Y.; Nakayasu, T.; Enokida, Y.; Koyama, M.; Saito, K.; Ozaki, S.; Tsuneta, S.

    2014-07-01

    We present an innovative optical design for image slicer integral field unit (IFU) and manufacturing method which overcome optical limitation of metallic mirrors. Our IFU consists of micro image slicer of 45 arrayed highly-narrow flat metallic mirrors and a pseudo pupil mirror array of off-axis conic aspheres forming three pseudo slits of re-arranged slicer images. A prototype IFU demonstrates their optical quality high enough for a visible light spectrograph. The each slicer mirror is 1.58 mm in length and 30μm in width with surface roughness < 1 nm rms, edge sharpness < 0.1μm, etc. This IFU is small-sized and can be implemented in a multi-slit spectrograph without any moving mechanism and fore optics in which one slit is real and the others are of pseudo slits from the IFU. Those properties are well suitable for space-borne spectrograph to be aboard such as a next Japanese solar mission SOLAR-C.

  13. Using Correlation Tracking to Disentangle Spatial and Spectral Data in a Slitless Spectrograph

    NASA Astrophysics Data System (ADS)

    Courrier, Hans; Kankelborg, Charles

    2015-04-01

    In a typical slit style spectrograph, the limited field of view afforded by the entrance slit is overcome by rastering the slit across a feature of interest to build a composite image. While it is trivial to separate spatial and spectral data in such an instrument, the cadence of the raster results in a loss of temporal data when attempting to image a feature that is much larger than the entrance slit. The Multi-Order Solar EUV Spectrograph (MOSES) is a slitless spectrograph that collects co-temporal spatial and spectral images in He II 304 Å over a 10’ x 20’ field of view through the use of a spherical diffraction grating. Local correlation tracking routines are used to disentangle the spatial and spectral data from images formed by the zero and both first orders of the MOSES instrument. The opposing dispersion direction of the outboard orders allows a diagnostic of the viability of the method when analyzing images obtained from the February 2006 MOSES sounding rocket flight.

  14. A color spectrographic phonocardiography (CSP) applied to the detection and characterization of heart murmurs: preliminary results

    PubMed Central

    2011-01-01

    Background Although cardiac auscultation remains important to detect abnormal sounds and murmurs indicative of cardiac pathology, the application of electronic methods remains seldom used in everyday clinical practice. In this report we provide preliminary data showing how the phonocardiogram can be analyzed using color spectrographic techniques and discuss how such information may be of future value for noninvasive cardiac monitoring. Methods We digitally recorded the phonocardiogram using a high-speed USB interface and the program Gold Wave http://www.goldwave.com in 55 infants and adults with cardiac structural disease as well as from normal individuals and individuals with innocent murmurs. Color spectrographic analysis of the signal was performed using Spectrogram (Version 16) as a well as custom MATLAB code. Results Our preliminary data is presented as a series of seven cases. Conclusions We expect the application of spectrographic techniques to phonocardiography to grow substantially as ongoing research demonstrates its utility in various clinical settings. Our evaluation of a simple, low-cost phonocardiographic recording and analysis system to assist in determining the characteristic features of heart murmurs shows promise in helping distinguish innocent systolic murmurs from pathological murmurs in children and is expected to useful in other clinical settings as well. PMID:21627809

  15. Astronomical optical frequency comb generation and test in a fiber-fed MUSE spectrograph

    NASA Astrophysics Data System (ADS)

    Chavez Boggio, J. M.; Fremberg, T.; Moralejo, B.; Rutowska, M.; Hernandez, E.; Zajnulina, M.; Kelz, A.; Bodenmüller, D.; Sandin, C.; Wysmolek, M.; Sayinc, H.; Neumann, J.; Haynes, R.; Roth, M. M.

    2014-07-01

    We here report on recent progress on astronomical optical frequency comb generation at innoFSPEC-Potsdam and present preliminary test results using the fiber-fed Multi Unit Spectroscopic Explorer (MUSE) spectrograph. The frequency comb is generated by propagating two free-running lasers at 1554.3 and 1558.9 nm through two dispersionoptimized nonlinear fibers. The generated comb is centered at 1590 nm and comprises more than one hundred lines with an optical-signal-to-noise ratio larger than 30 dB. A nonlinear crystal is used to frequency double the whole comb spectrum, which is efficiently converted into the 800 nm spectral band. We evaluate first the wavelength stability using an optical spectrum analyzer with 0.02 nm resolution and wavelength grid of 0.01 nm. After confirming the stability within 0.01 nm, we compare the spectra of the astro-comb and the Ne and Hg calibration lamps: the astro-comb exhibits a much larger number of lines than lamp calibration sources. A series of preliminary tests using a fiber-fed MUSE spectrograph are subsequently carried out with the main goal of assessing the equidistancy of the comb lines. Using a P3d data reduction software we determine the centroid and the width of each comb line (for each of the 400 fibers feeding the spectrograph): equidistancy is confirmed with an absolute accuracy of 0.4 pm.

  16. An optical design for a wide-field optical spectrograph for TMT

    NASA Astrophysics Data System (ADS)

    Bernstein, Rebecca A.; Bigelow, Bruce C.

    2008-07-01

    We describe a preliminary optical design for a multi-object, wide-field, optical echellette spectrograph that is intended to serve a broad range of science. It will produce low-resolution, single-order spectra for survey-mode programs targeting as many objects as possible and also moderate-resolution, multiple-order spectra for a reduced number of targets. The design uses all refracting optics. The first optical element of the spectrograph is a wide-field corrector for the telescope that causes the chief rays to be perpendicular to the focal plane. The collimator, which has been designed on-axis, can then be duplicated to target multiple, off-axis fields in a multiple-barrel configuration. The collimator optics include an achromatic field lens group that forms a sharp pupil over the full optical band-pass (320-1000 nm), followed by a dichroic which splits the beam into a red and a blue channel. All remaining optical elements of the collimator, the gratings, the cameras, and the detectors are then optimized for red or blue wavelengths. Both red and blue channels of each beam of the spectrograph use reflection gratings to produce either a single-order spectrum at resolutions around R=λ/Δλ=1000 or a five-order, R>5000 echellette spectrum with prism cross-dispersion. Both modes can target objects anywhere in the collimated field of view. A direct imaging mode will also be provided.

  17. The infrared imaging spectrograph (IRIS) for TMT: overview of innovative science programs

    NASA Astrophysics Data System (ADS)

    Wright, Shelley A.; Larkin, James E.; Moore, Anna M.; Do, Tuan; Simard, Luc; Adamkovics, Maté; Armus, Lee; Barth, Aaron J.; Barton, Elizabeth; Boyce, Hope; Cooke, Jeffrey; Cote, Patrick; Davidge, Timothy; Ellerbroek, Brent; Ghez, Andrea M.; Liu, Michael C.; Lu, Jessica R.; Macintosh, Bruce A.; Mao, Shude; Marois, Christian; Schoeck, Matthias; Suzuki, Ryuji; Tan, Jonathan C.; Treu, Tommaso; Wang, Lianqi; Weiss, Jason

    2014-07-01

    IRIS (InfraRed Imaging Spectrograph) is a first light near-infrared diffraction limited imager and integral field spectrograph being designed for the future Thirty Meter Telescope (TMT). IRIS is optimized to perform astronomical studies across a significant fraction of cosmic time, from our Solar System to distant newly formed galaxies (Barton et al. [1]). We present a selection of the innovative science cases that are unique to IRIS in the era of upcoming space and ground-based telescopes. We focus on integral field spectroscopy of directly imaged exoplanet atmospheres, probing fundamental physics in the Galactic Center, measuring 104 to 1010 M supermassive black hole masses, resolved spectroscopy of young star-forming galaxies (1 < z < 5) and first light galaxies (6 < z < 12), and resolved spectroscopy of strong gravitational lensed sources to measure dark matter substructure. For each of these science cases we use the IRIS simulator (Wright et al. [2], Do et al. [3]) to explore IRIS capabilities. To highlight the unique IRIS capabilities, we also update the point and resolved source sensitivities for the integral field spectrograph (IFS) in all five broadband filters (Z, Y, J, H, K) for the finest spatial scale of 0.004" per spaxel. We briefly discuss future development plans for the data reduction pipeline and quicklook software for the IRIS instrument suite.

  18. The first VisAO-fed integral field spectrograph: VisAO IFS

    NASA Astrophysics Data System (ADS)

    Follette, Katherine B.; Close, Laird M.; Kopon, Derek; Males, Jared R.; Gasho, Victor; Brutlag, Kevin M.; Uomoto, Alan

    2010-07-01

    We present the optomechanical design of the Magellan VisAO Integral Field Spectrograph (VisAO IFS), designed to take advantage of Magellan's AO system and its 85.1cm concave ellipsoidal Adaptive Secondary Mirror (ASM). With 585 actuators and an equal number of actively-controlled modes, this revolutionary second generation ASM will be the first to achieve moderate Strehl ratios into the visible wavelength regime. We have designed the VisAO IFS to be coupled to either Magellan's LDSS-3 spectrograph or to the planned facility M2FS fiber spectrograph and to optimize VisAO science. Designed for narrow field-of-view, high spatial resolution science, this lenslet-coupled fiberfed IFS will offer exciting opportunities for scientific advancement in a variety of fields, including protoplanetary disk morphology and chemistry, resolution and spectral classification of tight astrometric binaries, seasonal changes in the upper atmosphere of Titan, and a better understanding of the black hole M-sigma relation.

  19. A Flexible and Modular Data Reduction Library for Fiber-fed Echelle Spectrographs

    NASA Astrophysics Data System (ADS)

    Sosnowska, D.; Lovis, C.; Figueira, P.; Modigliani, A.; Marcantonio, P. D.; Megevand, D.; Pepe, F.

    2015-09-01

    Within the ESPRESSO project a new flexible data reduction library is being built. ESPRESSO, the Echelle SPectrograph for Rocky Exoplanets and Stable Spectral Observations is a fiber-fed, high-resolution, cross-dispersed echelle spectrograph. One of its main scientific goals is to search for terrestrial exoplanets using the radial velocity technique. A dedicated pipeline is being developed. It is designed to be able to reduce data from different similar spectrographs: not only ESPRESSO, but also HARPS, HARPS-N and possibly others. Instrument specifics are configurable through an input static configuration table. The first written recipes are already tested on HARPS and HARPS-N real data and ESPRESSO simulated data. The final scientific products of the pipeline will be the extracted 1-dim and 2-dim spectra. Using these products the radial velocity of the observed object can be computed with high accuracy. The library is developed within the standard ESO pipeline environment. It is being written in ANSI C and makes use of the Common Pipeline Library (CPL). It can be used in conjunction with the ESO tools Esorex, Gasgano and Reflex in the usual way.

  20. In-flight Optical Performance of the Space Telescope Imaging Spectrograph

    NASA Astrophysics Data System (ADS)

    Bowers, C.; Hartig, G.; Kaiser, M.; Kraemer, S.; Gull, T.; Kimble, R.; Woodgate, B.; Bohlin, R.; Plait, P.; Lindler, D.; Ebbets, D.; Sullivan, J.; Hill, R. S.; Kinney, E.; Sahu, K.; Crenshaw, M.; Collins, N.; Danks, A.; Robinson, R.; Cornett, R.; Gruzyzak, A.

    1997-05-01

    The Space Telescope Imaging Spectrograph (STIS) was installed aboard the Hubble Space Telescope (HST) in February, 1997, replacing the Goddard High Resolution Spectrograph and the Faint Object Spectrograph. STIS also incorporates an internal, two mirror relay system replacing COSTAR to correct the spherical aberration and astigmatism present at the STIS field position. STIS operates over the full HST wavelength range, from the ultraviolet to near infrared (115-1000nm). Spectroscopic modes permit low and medium resolution spectroscopy throughout the spectral range and over 25 arcsecond ultraviolet and 52 arcsecond visible fields. High resolution (30-100,000) echelle spectroscopy capability is also provided in the ultraviolet (115-310nm). Broad band imaging is possible over the complete spectral range and a small selection of bandpass filters are available. A wide selection of slits and apertures permit various resolution and spatial scales to be selected in all modes. Coronagraphic stops are also provided for observations in the visible (310-1000nm). On board calibration lamps provide wavelength calibration and flat fielding capability. The initial optical performance results obtained during orbital verification are presented here. These include absolute throughput and stability, camera mode image quality, spectroscopic resolution, and filter and slit transmission.

  1. Compact boson stars in K field theories

    NASA Astrophysics Data System (ADS)

    Adam, C.; Grandi, N.; Klimas, P.; Sánchez-Guillén, J.; Wereszczyński, A.

    2010-11-01

    We study a scalar field theory with a non-standard kinetic term minimally coupled to gravity. We establish the existence of compact boson stars, that is, static solutions with compact support of the full system with self-gravitation taken into account. Concretely, there exist two types of solutions, namely compact balls on the one hand, and compact shells on the other hand. The compact balls have a naked singularity at the center. The inner boundary of the compact shells is singular, as well, but it is, at the same time, a Killing horizon. These singular, compact shells therefore resemble black holes.

  2. Modelling of compaction in planetesimals

    NASA Astrophysics Data System (ADS)

    Neumann, Wladimir; Breuer, Doris; Spohn, Tilman

    2014-07-01

    Aims: Compaction of initially porous material prior to melting is an important process that has influenced the interior structure and the thermal evolution of planetesimals in their early history. On the one hand, compaction decreases the porosity resulting in a reduction of the radius and on the other hand, the loss of porosity results in an increase of the thermal conductivity of the material and thus in a more efficient cooling. Porosity loss by hot pressing is the most efficient process of compaction in planetesimals and can be described by creep flow, which depends on temperature and stress. Hot pressing has been repeatedly modelled using a simplified approach, for which the porosity is gradually reduced in some fixed temperature interval between ≈650 K and 700 K. This approach neglects the dependence of compaction on stress and other factors such as matrix grain size and creep activation energy. In the present study, we compare this parametrised method with a self-consistent calculation of porosity loss via a creep related approach. Methods: We use our thermal evolution model from previous studies to model compaction of an initially porous body and consider four basic packings of spherical dust grains (simple cubic, orthorhombic, rhombohedral, and body-centred cubic). Depending on the grain packing, we calculate the effective stress and the associated porosity change via the thermally activated creep flow. For comparison, compaction is also modelled by simply reducing the initial porosity linearly to zero between 650 K and 700 K. As we are interested in thermal metamorphism and not melting, we only consider bodies that experience a maximum temperature below the solidus temperature of the metal phase. Results: For the creep related approach, the temperature interval in which compaction takes place depends strongly on the size of the planetesimal and is not fixed as assumed in the parametrised approach. Depending on the radius, the initial grain size, the

  3. Blue ellipticals in compact groups

    NASA Technical Reports Server (NTRS)

    Zepf, Stephen E.; Whitmore, Bradley C.

    1990-01-01

    By studying galaxies in compact groups, the authors examine the hypothesis that mergers of spiral galaxies make elliptical galaxies. The authors combine dynamical models of the merger-rich compact group environment with stellar evolution models and predict that roughly 15 percent of compact group ellipticals should be 0.15 mag bluer in B - R color than normal ellipticals. The published colors of these galaxies suggest the existence of this predicted blue population, but a normal distribution with large random errors can not be ruled out based on these data alone. However, the authors have new ultraviolet blue visual data which confirm the blue color of the two ellipticals with blue B - R colors for which they have their own colors. This confirmation of a population of blue ellipticals indicates that interactions are occurring in compact groups, but a blue color in one index alone does not require that these ellipticals are recent products of the merger of two spirals. The authors demonstrate how optical spectroscopy in the blue may distinguish between a true spiral + spiral merger and the swallowing of a gas-rich system by an already formed elliptical. The authors also show that the sum of the luminosity of the galaxies in each group is consistent with the hypothesis that the final stage in the evolution of compact group is an elliptical galaxy.

  4. Viral RNAs Are Unusually Compact

    PubMed Central

    Gopal, Ajaykumar; Egecioglu, Defne E.; Yoffe, Aron M.; Ben-Shaul, Avinoam; Rao, Ayala L. N.; Knobler, Charles M.; Gelbart, William M.

    2014-01-01

    A majority of viruses are composed of long single-stranded genomic RNA molecules encapsulated by protein shells with diameters of just a few tens of nanometers. We examine the extent to which these viral RNAs have evolved to be physically compact molecules to facilitate encapsulation. Measurements of equal-length viral, non-viral, coding and non-coding RNAs show viral RNAs to have among the smallest sizes in solution, i.e., the highest gel-electrophoretic mobilities and the smallest hydrodynamic radii. Using graph-theoretical analyses we demonstrate that their sizes correlate with the compactness of branching patterns in predicted secondary structure ensembles. The density of branching is determined by the number and relative positions of 3-helix junctions, and is highly sensitive to the presence of rare higher-order junctions with 4 or more helices. Compact branching arises from a preponderance of base pairing between nucleotides close to each other in the primary sequence. The density of branching represents a degree of freedom optimized by viral RNA genomes in response to the evolutionary pressure to be packaged reliably. Several families of viruses are analyzed to delineate the effects of capsid geometry, size and charge stabilization on the selective pressure for RNA compactness. Compact branching has important implications for RNA folding and viral assembly. PMID:25188030

  5. A calibration of the Naval Postgraduate School middle ultraviolet spectrograph and an analysis of the OII 2470 A emission obtained by the middle ultraviolet spectrograph

    NASA Astrophysics Data System (ADS)

    Hymas, Hewitt M.

    1994-06-01

    The NPS middle ultraviolet spectrograph, MUSTANG, instrument was tested using standard techniques to determine the wavelength calibration and overall sensitivity. The instrument was launched on March 10, 1994 on a NASA sounding rocket from Poker Flats, Alaska. Post-flight calibration indicates the wavelength calibration did not change as a result of the launch and no significant change in the sensitivity calibration. Ultraviolet dayglow spectra of the earth's ionosphere from 1800 A to 3400 A were obtained during a similar launch on March 19, 1992 from White Sands Missile Range, New Mexico. Data were obtained on the downleg of this earlier experiment and range in altitude from 115 km to 320 km. Analysis of the data from 2420 A to 2490 A was conducted to obtain the intensity profile of the OII 2470.4 A multiplet. The analysis used synthetic spectra generated for the N2 Vegard-Kaplan and the nitric-oxide gamma band emissions.

  6. Compact orthogonal NMR field sensor

    DOEpatents

    Gerald, II, Rex E.; Rathke, Jerome W.

    2009-02-03

    A Compact Orthogonal Field Sensor for emitting two orthogonal electro-magnetic fields in a common space. More particularly, a replacement inductor for existing NMR (Nuclear Magnetic Resonance) sensors to allow for NMR imaging. The Compact Orthogonal Field Sensor has a conductive coil and a central conductor electrically connected in series. The central conductor is at least partially surrounded by the coil. The coil and central conductor are electrically or electro-magnetically connected to a device having a means for producing or inducing a current through the coil and central conductor. The Compact Orthogonal Field Sensor can be used in NMR imaging applications to determine the position and the associated NMR spectrum of a sample within the electro-magnetic field of the central conductor.

  7. Compaction Behavior of Granular Materials

    NASA Astrophysics Data System (ADS)

    Endicott, Mark R.; Kenkre, V. M.; Glass, S. Jill; Hurd, Alan J.

    1996-03-01

    We report the results of our recent study of compaction of granular materials. A theoretical model is developed for the description of the compaction of granular materials exemplified by granulated ceramic powders. Its predictions are compared to observations of uniaxial compaction tests of ceramic granules of PMN-PT, spray dried alumina and rutile. The theoretical model employs a volume-based statistical mechanics treatment and an activation analogy. Results of a computer simulation of random packing of discs in two dimensions are also reported. The effect of type of particle size distribution and other parameters of that distribution on the calculated quantities are discussed. We examine the implications of the results of the simulation for the theoretical model.

  8. Modeling of compact loop antennas

    SciTech Connect

    Baity, F.W.

    1987-01-01

    A general compact loop antenna model which treats all elements of the antenna as lossy transmission lines has been developed. In addition to capacitively-tuned resonant double loop (RDL) antennas the model treats stub-tuned resonant double loop antennas. Calculations using the model have been compared with measurements on full-scale mockups of resonant double loop antennas for ATF and TFTR in order to refine the transmission line parameters. Results from the model are presented for RDL antenna designs for ATF, TFTR, Tore Supra, and for the Compact Ignition Tokamak (CIT).

  9. Compact monolithic capacitive discharge unit

    DOEpatents

    Roesler, Alexander W.; Vernon, George E.; Hoke, Darren A.; De Marquis, Virginia K.; Harris, Steven M.

    2007-06-26

    A compact monolithic capacitive discharge unit (CDU) is disclosed in which a thyristor switch and a flyback charging circuit are both sandwiched about a ceramic energy storage capacitor. The result is a compact rugged assembly which provides a low-inductance current discharge path. The flyback charging circuit preferably includes a low-temperature co-fired ceramic transformer. The CDU can further include one or more ceramic substrates for enclosing the thyristor switch and for holding various passive components used in the flyback charging circuit. A load such as a detonator can also be attached directly to the CDU.

  10. Modeling of compact loop antennas

    NASA Astrophysics Data System (ADS)

    Baity, F. W.

    A general compact loop antenna model which treats all elements of the antenna as lossy transmission lines has been developed. In addition to capacitively-tuned resonant double loop (RDL) antennas the model treats stub-tuned resonant double loop antennas. Calculations using the model have been compared with measurements on full-scale mockups of resonant double loop antennas for ATF and TFTR in order to refine the transmission line parameters. Results from the model are presented for RDL antenna designs for ATF, TFTR, Tore Supra, and for the Compact Ignition Tokamak (CIT).

  11. Modeling of compact loop antennas

    NASA Astrophysics Data System (ADS)

    Baity, F. W.

    1987-09-01

    A general compact loop antenna model which treats all elements of the antenna as lossy transmission lines has been developed. In addition to capacitively tuned resonant double loop (RDL) antennas, the model treats sub-tuned RDL antennas. Calculations using the model have been compared with measurements on full-scale mock-ups of RDL antennas for ATF and TFTR in order to refine the transmission line parameters. Results from the model are presented for RDL antenna designs for ATF, TFTR, Tore Supra, and the Compact Ignition Tokamak (CIT).

  12. Compact intermediates in RNA folding

    SciTech Connect

    Woodson, S.A.

    2011-12-14

    Large noncoding RNAs fold into their biologically functional structures via compact yet disordered intermediates, which couple the stable secondary structure of the RNA with the emerging tertiary fold. The specificity of the collapse transition, which coincides with the assembly of helical domains, depends on RNA sequence and counterions. It determines the specificity of the folding pathways and the magnitude of the free energy barriers to the ensuing search for the native conformation. By coupling helix assembly with nascent tertiary interactions, compact folding intermediates in RNA also play a crucial role in ligand binding and RNA-protein recognition.

  13. Compact accelerator for medical therapy

    DOEpatents

    Caporaso, George J.; Chen, Yu-Jiuan; Hawkins, Steven A.; Sampayan, Stephen E.; Paul, Arthur C.

    2010-05-04

    A compact accelerator system having an integrated particle generator-linear accelerator with a compact, small-scale construction capable of producing an energetic (.about.70-250 MeV) proton beam or other nuclei and transporting the beam direction to a medical therapy patient without the need for bending magnets or other hardware often required for remote beam transport. The integrated particle generator-accelerator is actuable as a unitary body on a support structure to enable scanning of a particle beam by direction actuation of the particle generator-accelerator.

  14. VARIABLE MOMENTUM COMPACTION LATTICE STUDIES.

    SciTech Connect

    KRAMER,S.; MURPHY,J.B.

    1999-03-29

    The VUV storage ring at the National Synchrotron Light Source was used to study the impact of changes in the momentum compaction factors over a large range from positive to negative values. Changes in bunch length and synchrotron tune were measured versus current and RF parameters for these different lattices. By controlling both the first and second-order momentum compaction factors, a lattice was developed in which a pair of alpha buckets was created within the energy aperture of the vacuum chamber and beam was stored simultaneously in both buckets.

  15. Compact remote multisensing instrument for planetary surfaces and atmospheres characterization.

    PubMed

    Nurul Abedin, M; Bradley, Arthur T; Ismail, Syed; Sharma, Shiv K; Sandford, Stephen P

    2013-05-10

    This paper describes a prototype feasibility demonstration system of a multipurpose Raman-fluorescence spectrograph and compact lidar system suitable for planetary sciences missions. The key measurement features of this instrument are its abilities to: i) detect minerals and organics at low levels in the dust constituents of surface, subsurface material and rocks on Mars, ii) determine the distribution of trace fluorescent ions with time-resolved fluorescence spectroscopy to learn about the geological conditions under which these minerals formed, iii) inspect material toxicity from a mobile robotic platform during local site characterization, iv) measure dust aerosol and cloud distributions, v) measure near-field atmospheric carbon dioxide, and vi) identify surface CO(2)-ice, surface water ice, and surface or subsurface methane hydrate. This prototype instrument and an improved follow-on design are described and have the capability for scientific investigations discussed above, to remotely investigate geological processes from a robotic platform at more than a 20-m radial distance with potential to go beyond 100 m. It also provides single wavelength (532 nm) aerosol/cloud profiling over very long ranges (>10 km with potential to 20 km). Measurement results obtained with this prototype unit from a robotic platform and calculated potential performance are presented in this paper. PMID:23669823

  16. 75 FR 62568 - Meeting of the Compact Council for the National Crime Prevention and Privacy Compact

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-12

    ... of the Council should notify the Federal Bureau of Investigation (FBI) Compact Officer, Mr. Gary S..., FBI Compact Officer, Compact Council Office, Module D3, 1000 Custer Hollow Road, Clarksburg,...

  17. Spectroscopic Survey of Eclipsing Binaries with a Low-cost Echelle Spectrograph: Scientific Commissioning

    NASA Astrophysics Data System (ADS)

    Kozłowski, S. K.; Konacki, M.; Sybilski, P.; Ratajczak, M.; Pawłaszek, R. K.; Hełminiak, K. G.

    2016-07-01

    We present scientific results obtained with a recently commissioned échelle spectrograph on the 0.5 m Solaris-1 telescope in the South African Astronomical Observatory. BACHES is a low-cost slit échelle spectrograph that has a resolution of 21,000 at 5500 Å. The described setup is fully remotely operated and partly automated. Custom hardware components have been designed to allow both spectroscopic and photometric observations. The setup is controlled via dedicated software. The throughput of the system allows us to obtain spectra with an average signal-to-noise ratio of 22 at 6375 Å for a 30 minute exposure of a V = 10 mag target. The stability of the instrument is influenced mainly by the ambient temperature changes. We have obtained radial velocity (RV) rms values for a bright (V = 5.9 mag) spectroscopic binary as good as 0.59 and 1.34 km s‑1 for a V = 10.2 mag eclipsing binary. RV measurements have been combined with available photometric light curves. We present models of six eclipsing binary systems, and for previously known targets, we compare our results with those available in the literature. Masses of binary components have been determined with 3% errors for some targets. We confront our results with benchmark values based on measurements from the HARPS and UCLES spectrographs on 4 m class telescopes and find very good agreement. The described setup is very efficient and well suited for a spectroscopic survey. We can now spectroscopically characterize about 300 eclipsing binary stars per year up to 10.2 mag assuming typical weather conditions at SAAO without a single observing trip.

  18. Optimization of a space spectrograph main frame and frequency response analysis of the frame

    NASA Astrophysics Data System (ADS)

    Zhang, Xin-yu; Chen, Zhi-yuan; Yang, Shi-mo

    2009-07-01

    A space spectrograph main structure is optimized and examined in order to satisfy the space operational needs. The space spectrograph will be transported into its operational orbit by the launch vehicle and it will undergo dynamic environment in the spacecraft injection period. The unexpected shocks may cause declination of observation accuracy and even equipment damages. The main frame is one of the most important parts because its mechanical performance has great influence on the operational life of the spectrograph, accuracy of observation, etc. For the reason of cost reduction and stability confirming, lower weight and higher structure stiffness of the frame are simultaneously required. Structure optimization was conducted considering the initial design modal analysis results. The base modal frequency raised 10.34% while the whole weight lowered 8.63% compared to the initial design. The purpose of this study is to analyze the new design of main frame mechanical properties and verify whether it can satisfy strict optical demands under the dynamic impact during spacecraft injection. For realizing and forecasting the frequency response characteristics of the main structure in mechanical environment experiment, dynamic analysis of the structure should be performed simulating impulse loads from the bottom base. Therefore, frequency response analysis (FRA) of the frame was then performed using the FEA software MSC.PATRAN/NASTRAN. Results of shock response spectrum (SRS) responses from the base excitations were given. Stress and acceleration dynamic responses of essential positions in the spacecraft injection course were also calculated and spectrometer structure design was examined considering stiffness / strength demands. In this simulation, maximum stresses of Cesic material in two acceleration application cases are 45.1 and 74.1 MPa, respectively. They are all less than yield strengths. As is demonstrated from the simulation, strength reservation of the frame is

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  20. Performance of the Southern African Large Telescope (SALT) High Resolution Spectrograph (HRS)

    NASA Astrophysics Data System (ADS)

    Crause, Lisa A.; Sharples, Ray M.; Bramall, David G.; Schmoll, Jürgen; Clark, Paul; Younger, Eddy J.; Tyas, Luke M. G.; Ryan, Sean G.; Brink, Janus D.; Strydom, Ockert J.; Buckley, David A. H.; Wilkinson, Martin; Crawford, Steven M.; Depagne, Éric

    2014-07-01

    The Southern African Large Telescope (SALT) High Resolution Spectrograph (HRS) is a fibre-fed R4 échelle spectrograph employing a white pupil design with red and blue channels for wavelength coverage from 370-890nm. The instrument has four modes, each with object and sky fibres: Low (R~15000), Medium (R~40000) and High Resolution (R~65000), as well as a High Stability mode for enhanced radial velocity precision at R~65000. The High Stability mode contains a fibre double-scrambler and offers optional simultaneous Th-Ar arc injection, or the inclusion of an iodine cell in the beam. The LR mode has unsliced 500μm fibres and makes provision for nod-and-shuffle for improved background subtraction. The MR mode also uses 500μm fibres, while the HR and HS fibres are 350μm. The latter three modes employ modified Bowen-Walraven image-slicers to subdivide each fibre into three slices. All but the High Stability bench is sealed within a vacuum tank, which itself is enclosed in an interlocking Styrostone enclosure, to insulate the spectrograph against temperature and atmospheric pressure variations. The Fibre Instrument Feed (FIF) couples the four pairs of fibres to the telescope focal plane and allows the selection of the appropriate fibre pair for a given mode, and adjustment of the fibre separation to optimally position the sky fibre. The HRS employs a photomultiplier tube for an exposure meter and has a dedicated auto-guider attached to the FIF. We report here on the commissioning results and overall instrument performance since achieving first light on 28 September 2013.

  1. Performance Results from In-Flight Commissioning of the Juno Ultraviolet Spectrograph (Juno-UVS)

    NASA Astrophysics Data System (ADS)

    Greathouse, Thomas K.; Gladstone, G. R.; Davis, M. W.; Slater, D. C.; Versteeg, M. H.; Persson, K. B.; Winters, G. S.; Persyn, S. C.; Eterno, J. S.

    2012-10-01

    We present a description of the Juno ultraviolet spectrograph (Juno-UVS), results from the successful in-flight commissioning performed between December 5th and 13th 2011, and some predictions of future Jupiter observations. Juno-UVS is a modest power (9.0 W) ultraviolet spectrograph based on the Alice instruments now in flight aboard the European Space Agency’s Rosetta spacecraft, NASA’s New Horizons spacecraft, and the LAMP instrument aboard NASA’s Lunar Reconnaissance Orbiter. However, unlike the other Alice spectrographs, Juno-UVS sits aboard a rotationally stabilized spacecraft. The planned 2 rpm rotation rate for the primary mission results in integration times per spatial resolution element per spin of only 17 ms. Thus, data was retrieved from many spins and then remapped and co-added to build up integration times on bright stars to measure the effective area, spatial resolution, map out scan mirror pointing positions, etc. The Juno-UVS scan mirror allows for pointing of the slit approximately ±30° from the spacecraft spin plane. This ability gives Juno-UVS access to half the sky at any given spacecraft orientation. We will describe our process for solving for the pointing of the scan mirror relative to the Juno spacecraft and present our initial half sky survey of UV bright stars complete with constellation overlays. The primary job of Juno-UVS will be to characterize Jupiter’s UV auroral emissions and relate them to in situ particle measurements. The ability to point the slit will facilitate these measurements, allowing Juno-UVS to observe the surface positions of magnetic field lines Juno is flying through giving a direct connection between the particle measurements on the spacecraft to the observed reaction of Jupiter’s atmosphere to those particles. Finally, we will describe planned observations to be made during Earth flyby in October 2013 that will complete the in-flight characterization.

  2. Performance results from in-flight commissioning of the Juno Ultraviolet Spectrograph (Juno-UVS)

    NASA Astrophysics Data System (ADS)

    Greathouse, T. K.; Gladstone, G. R.; Davis, M. W.; Slater, D. C.; Versteeg, M. H.; Persson, K. B.; Walther, B. C.; Winters, G. S.; Persyn, S. C.; Eterno, J. S.

    2013-09-01

    We present a description of the Juno ultraviolet spectrograph (Juno-UVS) and results from its in-flight commissioning performed between December 5th and 13th 2011 and its first periodic maintenance between October 10th and 12th 2012. Juno-UVS is a modest power (9.0 W) ultraviolet spectrograph based on the Alice instruments now in flight aboard the European Space Agency's Rosetta spacecraft, NASA's New Horizons spacecraft, and the LAMP instrument aboard NASA's Lunar Reconnaissance Orbiter. However, unlike the other Alice spectrographs, Juno-UVS sits aboard a spin stabilized spacecraft. The Juno-UVS scan mirror allows for pointing of the slit approximately +/-30° from the spacecraft spin plane. This ability gives Juno-UVS access to half the sky at any given spacecraft orientation. The planned 2 rpm spin rate for the primary mission results in integration times per 0.2° spatial resolution element per spin of only ~17 ms. Thus, for calibration purposes, data were retrieved from many spins and then remapped and co-added to build up exposure times on bright stars to measure the effective area, spatial resolution, scan mirror pointing positions, etc. The primary job of Juno-UVS will be to characterize Jupiter's UV auroral emissions and relate them to in-situ particle measurements. The ability to point the slit will make operations more flexible, allowing Juno-UVS to observe the atmospheric footprints of magnetic field lines through which Juno flies, giving a direct connection between energetic particle measurements on the spacecraft and the far-ultraviolet emissions produced by Jupiter's atmosphere in response to those particles.

  3. Demonstrator of a multi-object spectrograph based on the 2048×1080 DMD

    NASA Astrophysics Data System (ADS)

    Zamkotsian, Frederic; Spano, Paolo; Bon, William; Lanzoni, Patrick

    2012-03-01

    Multi-Object Spectrographs (MOS) are the major instruments for studying primary galaxies and remote and faint objects. Current object selection systems are limited and/or difficult to implement in next generation MOS for space and ground-based telescopes. A promising solution is the use of MOEMS devices such as micromirror arrays which allow the remote control of the multi-slit configuration in real time. We are developing a Digital Micromirror Device (DMD) - based spectrograph demonstrator. We want to access the largest FOV with the highest contrast. The selected component is a DMD chip from Texas Instruments in 2048 × 1080 mirrors format, with a pitch of 13.68μm. Such component has been also studied by our team in early phase EUCLID-NIS study. Our optical design is an all-reflective spectrograph design with F/4 on the DMD component, including two arms, one spectroscopic channel and one imaging channel, thanks to the two stable positions of DMD micromirrors. This demonstrator permits the study of key parameters such as throughput, contrast and ability to remove background and spoiler sources, PSF effect. This study will be conducted in the visible with possible extension in the IR. The breadboard has been designed and is under realization before integration on a bench simulating an astronomical FOV. The demonstrator is of prime importance for characterizing the actual performance of this new family of instruments, as well as investigating the operational procedures on astronomical objects. If this demonstrator is successful, next step will be a demonstrator instrument placed on the Telescopio Nazionale Galileo.

  4. The SLICE, CHESS, and SISTINE Ultraviolet Spectrographs: Rocket-Borne Instrumentation Supporting Future Astrophysics Missions

    NASA Astrophysics Data System (ADS)

    France, Kevin; Hoadley, Keri; Fleming, Brian T.; Kane, Robert; Nell, Nicholas; Beasley, Matthew; Green, James C.

    2016-03-01

    NASA’s suborbital program provides an opportunity to conduct unique science experiments above Earth’s atmosphere and is a pipeline for the technology and personnel essential to future space astrophysics, heliophysics, and atmospheric science missions. In this paper, we describe three astronomy payloads developed (or in development) by the Ultraviolet Rocket Group at the University of Colorado. These far-ultraviolet (UV) (100-160nm) spectrographic instruments are used to study a range of scientific topics, from gas in the interstellar medium (accessing diagnostics of material spanning five orders of magnitude in temperature in a single observation) to the energetic radiation environment of nearby exoplanetary systems. The three instruments, Suborbital Local Interstellar Cloud Experiment (SLICE), Colorado High-resolution Echelle Stellar Spectrograph (CHESS), and Suborbital Imaging Spectrograph for Transition region Irradiance from Nearby Exoplanet host stars (SISTINE) form a progression of instrument designs and component-level technology maturation. SLICE is a pathfinder instrument for the development of new data handling, storage, and telemetry techniques. CHESS and SISTINE are testbeds for technology and instrument design enabling high-resolution (R>105) point source spectroscopy and high throughput imaging spectroscopy, respectively, in support of future Explorer, Probe, and Flagship-class missions. The CHESS and SISTINE payloads support the development and flight testing of large-format photon-counting detectors and advanced optical coatings: NASA’s top two technology priorities for enabling a future flagship observatory (e.g. the LUVOIR Surveyor concept) that offers factors of ˜50-100 gain in UV spectroscopy capability over the Hubble Space Telescope. We present the design, component level laboratory characterization, and flight results for these instruments.

  5. Integration of VIRUS spectrographs for the Hobby-Eberly Telescope Dark Energy Experiment

    NASA Astrophysics Data System (ADS)

    Heisler, J.; Mollison, N.; Soukup, I.; Hayes, R.; Hill, G. J.; Good, J.; Savage, R.; Vattiat, B.

    2010-07-01

    The Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) at the University of Texas McDonald Observatory will deploy the Visible Integral-Field Replicable Unit Spectrograph (VIRUS) to survey large areas of sky. VIRUS consists of up to 192 spectrographs deployed as 96 units. VIRUS units are fiber-fed and are housed in four enclosures making up the VIRUS Support Structure (VSS). Initial design studies established an optimal array size and an upper and lower bound on their placement relative to the existing telescope structure. Tradeoffs considering IFU (optical fiber) length, support structure mass and ease of maintenance have resulted in placement of four 3 × 8 arrays of spectrograph pairs, about mid-point in elevation relative to the fixed HET structure. Because of the desire to minimize impact on the modal performance of the HET, the VSS is required to be an independent, selfsupporting structure and will only be coupled at the base of the telescope. Analysis shows that it is possible to utilize the existing azimuth drives of the telescope, through this coupling, which will greatly simplify the design and reduce cost. Each array is contained in an insulated enclosure that will control thermal load by means of heat exchangers and use of facility coolant supply. Access for installation and maintenance on the top, front, and rear of the enclosures must be provided. The design and analysis presented in this paper must provide an optimum balance in meeting the stringent requirements for science and facility constraints such as cost, weight, access, and safety.

  6. The system software development for prime focus spectrograph on Subaru Telescope

    NASA Astrophysics Data System (ADS)

    Shimono, Atsushi; Tamura, Naoyuki; Sugai, Hajime; Karoji, Hiroshi

    2012-09-01

    The Prime Focus Spectrograph (PFS) is a wide field multi-fiber spectrograph using the prime focus of the Subaru telescope, which is capable of observing up to 2400 astronomical objects simultaneously. The instrument control software will manage the observation procedure communicating with subsystems such as the fiber positioner "COBRA", the metrology camera system, and the spectrograph and camera systems. Before an exposure starts, the instrument control system needs to access to a database where target lists provided by observers are stored in advance, and accurately position fibers onto astronomical targets as requested therein. This fiber positioning will be carried out interacting with the metrology system which measures the fiber positions. In parallel, the control system can issue a command to point the telescope to the target position and to rotate the instrument rotator. Finally the telescope pointing and the rotator angle will be checked by imaging bright stars and checking their positions on the auto-guide and acquisition cameras. After the exposure finishes, the data are collected from the detector systems and are finalized as FITS files to archive with necessary information. The observation preparation software is required, given target lists and a sequence of observation, to find optimal fiber allocations with maximizing the number of guide stars. To carry out these operations efficiently, the control system will be integrated seamlessly with a database system which will store information necessary for observation execution such as fiber configurations. In this article, the conceptual system design of the observation preparation software and the instrument control software will be presented.

  7. Comet 67P observations with LOTUS: a new near-UV spectrograph for the Liverpool Telescope

    NASA Astrophysics Data System (ADS)

    Marchant, Jon; Jermak, Helen; Steele, Iain; Snodgrass, Colin; Fitzsimmons, Alan; Jones, Geraint

    2015-11-01

    The European Space Agency’s Rosetta spacecraft has been orbiting comet 67P/Churyumov-Gerasimenko (hereinafter “67P”) since August 2014, providing in-situ measurements of the dust, gas and plasma content of the coma within ~100km of the nucleus. Supporting the mission is a world-wide coordinated campaign of simultaneous ground-based observations of 67P (www.rosetta-campaign.net), providing wider context of the outer coma and tail invisible to Rosetta. We can now compare these observations, augmented by "ground truth" from Rosetta, with those of other comets past and future that are only observed from Earth.The robotic Liverpool Telescope (LT) is part of this campaign due to its unique ability to flexibly and autonomously schedule regular observations over entire semesters. Its optical imagery has recently been supplemented by near-UV spectroscopy to observe the UV molecular bands below 4000Å that are of considerable interest to cometary science. The LT's existing spectrographs FRODOSpec and SPRAT cut off at 4000Å, so the Liverpool Telescope Optical-to-UV Spectrograph - LOTUS - was fast-track designed, built and deployed on-sky in just five months. LOTUS contains no moving parts; acquisition is made with the LT's IO:O imaging camera, and different width slits for calibration and science are selected by fine-tuning the telescope's pointing on an innovative "step" design in its single slit.We present here details of the LOTUS spectrograph, and some preliminary results of our ongoing observations of comet 67P.

  8. The Compact Project: Final Report.

    ERIC Educational Resources Information Center

    National Alliance of Business, Inc., Washington, DC.

    The National Alliance of Business (NAB) surveyed the 12 sites that participated in the Compact Project to develop and implement programs of business-education collaboration. NAB studied start-up activities, key players, conditions for collaboration, accomplishments, challenges, and future plans. Program outcomes indicated that building successful…

  9. Compact Circuit Preprocesses Accelerometer Output

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr.

    1993-01-01

    Compact electronic circuit transfers dc power to, and preprocesses ac output of, accelerometer and associated preamplifier. Incorporated into accelerometer case during initial fabrication or retrofit onto commercial accelerometer. Made of commercial integrated circuits and other conventional components; made smaller by use of micrologic and surface-mount technology.

  10. Generalized high order compact methods.

    SciTech Connect

    Spotz, William F.; Kominiarczuk, Jakub

    2010-09-01

    The fundamental ideas of the high order compact method are combined with the generalized finite difference method. The result is a finite difference method that works on unstructured, nonuniform grids, and is more accurate than one would classically expect from the number of grid points employed.

  11. Mesoscale Simulations of Power Compaction

    SciTech Connect

    Lomov, I; Fujino, D; Antoun, T; Liu, B

    2009-08-06

    Mesoscale 3D simulations of metal and ceramic powder compaction in shock waves have been performed with an Eulerian hydrocode GEODYN. The approach was validated by simulating shock compaction of porous well-characterized ductile metal using Steinberg material model. Results of the simulations with handbook values for parameters of solid 2024 aluminum have good agreement with experimental compaction curves and wave profiles. Brittle ceramic materials are not so well studied as metals, so material model for ceramic (tungsten carbide) has been fitted to shock compression experiments of non-porous samples and further calibrated to match experimental compaction curves. Direct simulations of gas gun experiments with ceramic powder have been performed and showed good agreement with experimental data. Numerical shock wave profile has same character and thickness as measured with VISAR. Numerical results show reshock states above the single-shock Hugoniot line also observed in experiments. They found that to receive good quantitative agreement with experiment it is essential to perform 3D simulations.

  12. Mesoscale simulations of powder compaction

    NASA Astrophysics Data System (ADS)

    Lomov, Ilya; Antoun, Tarabay; Liu, Benjamin

    2009-06-01

    Mesoscale 3D simulations of metal and ceramic powder compaction in shock waves have been performed with an Eulerian hydrocode GEODYN. The approach was validated by simulating shock compaction of porous well-characterized ductile metal using Steinberg material model. Results of the simulations with handbook values for parameters of solid 2024 aluminum have good agreement with experimental compaction curves and wave profiles. Brittle ceramic materials are not so well studied as metals, so material model for ceramic (tungsten carbide) has been fitted to shock compression experiments of non-porous samples and further calibrated to experimental match compaction curves. Direct simulations of gas gun experiments with ceramic powder have been performed and showed good agreement with experimental data. Numerical shock wave profile has same character and thickness as measured with VISAR. Numerical results show evidence of hard-to-explain reshock states above the single-shock Hugoniot line, which have also been observed in the experiments. We found that to receive good quantitative agreement with experiment it is essential to perform 3D simulations, since 2D results tend to underpredict stress levels for high-porosity powders regardless of material properties. We developed a process to extract macroscale information for the simulation which can be directly used in calibration of continuum model for heterogeneous media.

  13. Compact color schlieren optical system

    NASA Technical Reports Server (NTRS)

    Buchele, Donald R.; Griffin, Devon W.

    1993-01-01

    A compact optical system for use with rainbow schlieren deflectometry is described. Both halves of the optical system consist of well-corrected telescopes whose refractive elements are all from manufacturer's stock catalogs, with the reflective primary being a spherical surface. As a result, the system is relatively easy to construct and meets the requirement of long focal length for quantitative rainbow schlieren measurements.

  14. Calibration of an astrophysical spectrograph below 1 m/s using a laser frequency comb

    NASA Astrophysics Data System (ADS)

    Phillips, David F.; Glenday, Alexander G.; Li, Chih-Hao; Cramer, Claire; Furesz, Gabor; Chang, Guoqing; Benedick, Andrew J.; Chen, Li-Jin; Kärtner, Franz X.; Korzennik, Sylvain; Sasselov, Dimitar; Szentgyorgyi, Andrew; Walsworth, Ronald L.

    2012-06-01

    We deployed two wavelength calibrators based on laser frequency combs ("astro-combs") at an astronomical telescope. One astro-comb operated over a 100 nm band in the deep red (∼ 800 nm) and a second operated over a 20 nm band in the blue (∼ 400 nm). We used these red and blue astro-combs to calibrate a high-resolution astrophysical spectrograph integrated with a 1.5 m telescope, and demonstrated calibration precision and stability suffici ent to enable detection of changes in stellar radial velocity < 1 m/s.

  15. Development of a miniaturized, light-weight magnetic sector for a field-portable mass spectrograph

    NASA Technical Reports Server (NTRS)

    Sinha, M. P.; Tomassian, A. D.

    1991-01-01

    A miniaturized, lightweight magnetic sector for a focal plane mass spectrograph (Mattauch-Herzog design) has been designed and fabricated by using a new high-energy-product magnet material (Nd-B-Fe alloy) and a high permeability magnet yoke material (V-Co-Fe alloy). The magnetic sector weighs less than 10 kg, has a focal plane of 5.1 cm in length, and covers a nominal mass range of 40-240 amu. Such a magnetic sector, in conjunction with an array detector and a short microbore capillary column, is well suited for the development of a field-portable gas chromatograph-mass spectrometer instrument of high performance.

  16. The Addition of EI/CI Capability to the Mattauch-herzog Spectrograph with EOID

    NASA Technical Reports Server (NTRS)

    Fergusson, G. J.; Koslin, M. E.

    1979-01-01

    A modification was made to the Mattauch-Herzog Spectrograph with an electro-optical ion detector (EOID) previously designed and constructed, so that it would be capable of operating not only in the electron-impact (EI) mode of ionization, but also in the chemical ionization (CI) mode. This modification necessitated an effort in three specific design areas: (1) sample inlet; (2) ion source and analyzer regions; and (3) the pumping system. In addition, an appropriate electronics package had to be designed to control and operate the combined EI/CI source.

  17. Calibration of an astrophysical spectrograph below 1 m/s using a laser frequency comb.

    PubMed

    Phillips, David F; Glenday, Alexander G; Li, Chih-Hao; Cramer, Claire; Furesz, Gabor; Chang, Guoqing; Benedick, Andrew J; Chen, Li-Jin; Kärtner, Franz X; Korzennik, Sylvain; Sasselov, Dimitar; Szentgyorgyi, Andrew; Walsworth, Ronald L

    2012-06-18

    We deployed two wavelength calibrators based on laser frequency combs ("astro-combs") at an astronomical telescope. One astro-comb operated over a 100 nm band in the deep red (∼ 800 nm) and a second operated over a 20 nm band in the blue (∼ 400 nm). We used these red and blue astro-combs to calibrate a high-resolution astrophysical spectrograph integrated with a 1.5 m telescope, and demonstrated calibration precision and stability sufficient to enable detection of changes in stellar radial velocity < 1 m/s. PMID:22714437

  18. The control unit of the near infrared spectrograph of the EUCLID space mission: preliminary design

    NASA Astrophysics Data System (ADS)

    Toledo-Moreo, Rafael; Colodro-Conde, Carlos; Díaz-García, José Javier; Tubío-Araujo, Óscar Manuel; Gómez-Sáenz, Jaime; Peña-Godino, Antonio; Velasco-Fernández, Tirso; Sánchez-Prieto, Sebastián.; Villó-Pérez, Isidro; Rebolo-López, Rafael

    2014-08-01

    The Near Infrared Spectrograph and Photometer (NISP) is one of the instruments on board the ESA EUCLID mission. The Universidad Politecnica de Cartagena and Instituto de Astrofisica de Canarias are responsible of the Instrument Control Unit of the NISP (NI-ICU) in the Euclid Consortium. The NI-ICU main functions are: communication with the S/C and the Data Processing Unit, control of the Filter and Grism Wheels, control of the Calibration Unit and thermal control of the instrument. This paper presents the NI-ICU status of definition and design at the end of the preliminary design phase.

  19. Spectrographic phase-retrieval algorithm for femtosecond and attosecond pulses with frequency gaps

    NASA Astrophysics Data System (ADS)

    Seifert, B.; Wallentowitz, S.; Volkmann, U.; Hause, A.; Sperlich, K.; Stolz, H.

    2014-10-01

    We present a phase-reconstruction algorithm for a self-referenced spectrographic pulse characterization technique called “very advanced method for phase and intensity retrieval of e-fields” (VAMPIRE). This technique permits a spectral phase reconstruction of pulses with separated frequency components. The algorithm uses the particular characteristics of VAMPIRE spectrograms. It is a locally structured algorithm which is fast, robust, and it allows us to master stagnation problems. The algorithm is tested by use of both simulated and measured data.

  20. Progress on the Gemini High-Resolution Optical SpecTrograph (GHOST) design

    NASA Astrophysics Data System (ADS)

    Ireland, Michael; Anthony, Andre; Burley, Greg; Chisholm, Eric; Churilov, Vladimir; Dunn, Jennifer; Frost, Gabriella; Lawrence, Jon; Loop, David; McGregor, Peter; Martell, Sarah; McConnachie, Alan; McDermid, Richard M.; Pazder, John; Reshetov, Vlad; Robertson, J. G.; Sheinis, Andrew; Tims, Julia; Young, Peter; Zhelem, Ross

    2014-07-01

    The Gemini High-Resolution Optical SpecTrograph (GHOST) is the newest instrument being developed for the Gemini telescopes, in a collaboration between the Australian Astronomical Observatory (AAO), the NRC - Herzberg in Canada and the Australian National University (ANU). We describe the process of design optimisation that utilizes the unique strengths of the new partner, NRC - Herzberg, the design and need for the slit viewing camera system, and we describe a simplification for the lenslet-based slit reformatting. Finally, we out- line the updated project plan, and describe the unique scientific role this instrument will have in an international context, from exoplanets through to the distant Universe.

  1. High-resolution fibre-fed spectrograph for the 6-m telescope. Polarimetric unit

    NASA Astrophysics Data System (ADS)

    Kukushkin, D. E.; Sazonenko, D. A.; Bakholdin, A. V.; Yushkin, M. V.; Bychkov, V. D.

    2016-04-01

    We report the computation of the design of a polarimetric unit for the optical scheme of the fiberfed high-resolution spectrograph for the 6-m Russian telescope.We discuss a variant of its integration into the design of conversion optics at the input of the fiber path if the instrument and estimate the efficiency of the entire pre-fiber optical system. The luminous efficiency of the assembly is equal to 80 and 90% when operated in the polarimetry and normal spectroscopic modes, respectively.We estimate the lower limit for the distorting instrumental effects of the polarimetric unit.

  2. The new Teledyne NIR detectors for the SNAP/JDEM mission spectrograph

    NASA Astrophysics Data System (ADS)

    Crouzet, P. E.

    2009-10-01

    A new generation of near infrared (NIR) detectors have been developed by Teledyne for the SNAP/JDEM (SuperNova/Acceleration Probe) project. The new detectors are hybridized HgCdTe on a multiplexer with indium bump bonded. Since 2004, Teledyne and the SNAP collaboration have tried to characterize and improve the large format (2k×2k) H2RG detectors to meet the SNAP requirements. The results for quantum efficiency and total noise as an integration of a H2RG in a spectrograph demonstrator are presented.

  3. The opto-mechanical design of the Colorado High-resolution Echelle Stellar Spectrograph (CHESS)

    NASA Astrophysics Data System (ADS)

    Kane, Robert; Beasley, Matthew; Green, James; Burgh, Eric; France, Kevin

    2011-09-01

    We present the Colorado High-resolution Echelle Stellar Spectrograph (CHESS) sounding rocket payload. The design uses a mechanical collimator made from a grid of square tubing, an objective echelle grating, a holographically-ruled cross-disperser, a new 40 mm MCP with a cross strip anode or a delta-doped 3.5k x 3.5k CCD detector. The optics are suspended using carbon fiber rods epoxied to titanium inserts to create a space frame structure. A preliminary design is presented.

  4. Apollo 16 far-ultraviolet camera/spectrograph - Instrument and operations.

    NASA Technical Reports Server (NTRS)

    Carruthers, G. R.

    1973-01-01

    A far-ultraviolet camera/spectrograph experiment was designed and constructed for studies of the terrestrial upper atmosphere and geocorona, the interplanetary medium, and celestial objects from the lunar surface. The experiment was successfully operated during the Apollo 16 mission 21-23 April 1972. Discussed are the design and operating principles of the instrument, the actual events and operations during the Apollo 16 mission, and also anomalies encountered and suggested improvements for future experiments of this type. This experiment demonstrated the utility of the electronographic technique in space astronomy, as well as the great potential of the lunar surface as a base for astronomical observations.

  5. Detector Arrays for the James Webb Space Telescope Near-Infrared Spectrograph

    NASA Technical Reports Server (NTRS)

    Rauscher, Bernard J.; Alexander, David; Brambora, Clifford K.; Derro, Rebecca; Engler, Chuck; Fox, Ori; Garrison, Matthew B.; Henegar, Greg; Hill, robert J.; Johnson, Thomas; Lindler, Don J.; Manthripragada, Sridhar S.; Marshall, Ceryl; Mott, Brent; Parr, Thomas M.; Roher, Wayne D.; Shakoorzadeh, Kamdin B.; Smith, Miles; Waczynski, Augustyn; Wen, Yiting; Wilson, Donna; Xia-Serafino, Wei

    2007-01-01

    The James Webb Space Telescope's (JWST) Near Infrared Spectrograph (NIRSpec) incorporates two 5 micron cutoff (lambda(sub co) = 5 microns) 2048x2048 pixel Teledyne HgCdTe HAWAII-2RG sensor chip assemblies. These detector arrays, and the two Teledyne SIDECAR application specific integrated circuits that control them, are operated in space at T approx. 37 K. In this article, we provide a brief introduction to NIRSpec, its detector subsystem (DS), detector readout in the space radiation environment, and present a snapshot of the developmental status of the NIRSpec DS as integration and testing of the engineering test unit begins.

  6. New and Better H2RG Detectors for the JWST Near Infrared Spectrograph

    NASA Astrophysics Data System (ADS)

    Rauscher, Bernard J.

    2014-01-01

    Remanufacturing of the near-infrared H2RG detectors for the James Webb Space Telescope (JWST) is nearing completion. The first of the Near Infrared Spectrograph (NIRSpec) flight candidates were delivered on-schedule this summer. We tested the detectors at Teledyne and characterized them in the Goddard Detector Characterization Laboratory (DCL), with excellent agreement between the two labs. Here we describe the DCL results which show the new detectors to be even better than the previous flight detectors. Highlights include improvements in the transimpedance gain that will reduce read noise and generally excellent QE over the full bandpass.

  7. Performance, results, and prospects of the visible spectrograph VEGA on CHARA

    NASA Astrophysics Data System (ADS)

    Mourard, Denis; Challouf, Mounir; Ligi, Roxanne; Bério, Philippe; Clausse, Jean-Michel; Gerakis, Jérôme; Bourges, Laurent; Nardetto, Nicolas; Perraut, Karine; Tallon-Bosc, Isabelle; McAlister, H.; ten Brummelaar, T.; Ridgway, S.; Sturmann, J.; Sturmann, L.; Turner, N.; Farrington, C.; Goldfinger, P. J.

    2012-07-01

    In this paper, we review the current performance of the VEGA/CHARA visible spectrograph and make a review of the most recent astrophysical results. The science programs take benefit of the exceptional angular resolution, the unique spectral resolution and one of the main features of CHARA: Infrared and Visible parallel operation. We also discuss recent developments concerning the tools for the preparation of observations and important features of the data reduction software. A short discussion of the future developments will complete the presentation, directed towards new detectors and possible new beam combination scheme for improved sensitivity and imaging capabilities.

  8. Design of a radial velocity spectrograph for the Moletai Astronomical Observatory

    NASA Astrophysics Data System (ADS)

    Jurgenson, Colby A.; Fischer, Debra A.; McCracken, Tyler M.; Stoll, Rebecca A.; Szymkowiak, Andrew E.; Giguere, Matt J.; Santoro, Fernando G.; Muller, Gary

    2014-07-01

    The Yale Exoplanet Laboratory is under contract to design, build, and deliver a high-resolution (R = 60,000) echelle spectrograph for the Moletai Astronomical Observatory 1.65-meter telescope at the Vilnius University. We present a fiber-fed, white-pupil architecture that will operate from 400 to 880nm. The optomechanical design implements a modular approach for stability and ease of alignment that can be reproduced for other telescopes. It will utilize highperformance off-the-shelf optical components with a custom designed refractive camera for high throughput and good image quality.

  9. The BUSS spectrum of Beta Lyrae. [Balloon-borne Ultraviolet Stellar Spectrograph

    NASA Technical Reports Server (NTRS)

    Hack, M.; Sahade, J.; De Jager, C.; Kondo, Y.

    1983-01-01

    The spectrum of Beta Lyrae from about 1975 to 3010 A taken with the Balloon-borne ultraviolet Stellar Spectrograph experiment in May 1976 at phase 0.61 P is analyzed. Results show the presence of N II semi-forbidden emission and provide evidence for about the same location, in the outer envelope of the system, of the layers responsible for the resonance Mg II doublet emissions and for the "narrow" H-alpha emission. In addition, three sets of absorption lines, P Cygni profiles of Fe III and broad Beals Type III emissions of Mg II, are found to be present.

  10. The simulated space proton environment for radiation effects on Space Telescope Imaging Spectrograph (STIS)

    NASA Technical Reports Server (NTRS)

    Becher, Jacob; Fowler, Walter

    1992-01-01

    The space telescope imaging spectrograph (STIS) is a second generation instrument planned for the Hubble Space Telescope (HST) which is currently in orbit. Candidate glasses and other transmitting materials are being considered for order sorters, in-flight calibration filters, detector windows, and calibration lamps. The glasses for in-flight calibration filters showed significant drop in UV transmission, but can probably still be used on STIS. The addressed topics include the Hubble radiation environment, simulation of orbital exposure at Harvard Cyclotron Laboratory, measurement of spectral transmission, and comments on individual samples.

  11. Compact CFB: The next generation CFB boiler

    SciTech Connect

    Utt, J.

    1996-12-31

    The next generation of compact circulating fluidized bed (CFB) boilers is described in outline form. The following topics are discussed: compact CFB = pyroflow + compact separator; compact CFB; compact separator is a breakthrough design; advantages of CFB; new design with substantial development history; KUHMO: successful demo unit; KUHMO: good performance over load range with low emissions; KOKKOLA: first commercial unit and emissions; KOKKOLA: first commercial unit and emissions; compact CFB installations; next generation CFB boiler; grid nozzle upgrades; cast segmented vortex finders; vortex finder installation; ceramic anchors; pre-cast vertical bullnose; refractory upgrades; and wet gunning.

  12. Compaction in the Bushveld Complex

    NASA Astrophysics Data System (ADS)

    Boorman, S.; Boudreau, A.

    2003-12-01

    Compaction in the mush zone of a crystallizing chamber is a model for fractionation, whereby evolved interstitial liquid expelled from the compacting crystal pile is returned to the magma chamber. If compaction was important during crystallization of the Lower and Critical Zones of the Bushveld Complex, certain textural features are expected; and, these features should correlate to position in the section, as well as to the number of mineral phases present. We report on a spectrum of textural data for 30 samples form the Lower and Critical Zones of the Bushveld Complex. Crystal Size Distributions (CSDs) are a semi-log plot of population density against crystal size, and provide information about magmatic processes such as crystal accumulation, removal and aging. Changes to the magmatic system are reflected in the shape of the CSD plot. CSDs of Bushveld rocks show a log-linear trend overturned at smaller grain sizes, a result consistent with both crystal aging, wherein larger grains grow at the expense of small ones in the crystallizing pile, and melt migration, where nucleation is suppressed by the loss of late melt fractions. CSD slope and intercept data vary with stratigraphy. Slopes in the Critical Zone are steeper, indicating less recrystallization and less of a compaction effect. In contrast, slopes in the Lower Zone are shallower, a result consistent with slower cooling and a greater compaction/recrystallization effect. Likewise, lower CSD intercepts are associated with the shallower slopes of the lower zone and vice versa. The extent of foliation is measured as alignment factor (AF), determined by orientation statistics of the major axes of the grains of interest. AF decreases with stratigraphic height and foliation is best developed in the nearly monomineralic harzburgite of the Lower Zone (AF avg=64). At the Lower Zone-Critical Zone transition, plagioclase content increases, decreasing bulk density and thus, the systems ability to accommodate compaction

  13. MID-INFRARED PROPERTIES OF NEARBY LUMINOUS INFRARED GALAXIES. I. SPITZER INFRARED SPECTROGRAPH SPECTRA FOR THE GOALS SAMPLE

    SciTech Connect

    Stierwalt, S.; Armus, L.; Surace, J. A.; Inami, H.; Petric, A. O.; Diaz-Santos, T.; Haan, S.; Howell, J.; Marshall, J.; Charmandaris, V.; Kim, D. C.; Mazzarella, J. M.; Chan, B.; Spoon, H. W. W.; Veilleux, S.; Evans, A.; Sanders, D. B.; Appleton, P.; Bothun, G.; Bridge, C. R.; and others

    2013-05-01

    The Great Observatories All-Sky LIRG Survey (GOALS) is a comprehensive, multiwavelength study of luminous infrared galaxies (LIRGs) in the local universe. Here we present low resolution Spitzer Infrared Spectrograph spectra covering 5-38 {mu}m and provide a basic analysis of the mid-IR spectral properties observed for nearby LIRGs. In a companion paper, we discuss detailed fits to the spectra and compare the LIRGs to other classes of galaxies. The GOALS sample of 244 nuclei in 180 luminous (10{sup 11} {<=} L {sub IR}/L {sub Sun} < 10{sup 12}) and 22 ultraluminous (L {sub IR}/L {sub Sun} {>=} 10{sup 12}) IR galaxies represents a complete subset of the IRAS Revised Bright Galaxy Sample and covers a range of merger stages, morphologies, and spectral types. The majority (>60%) of the GOALS LIRGs have high 6.2 {mu}m polycyclic aromatic hydrocarbon (PAH) equivalent widths (EQW{sub 6.2{mu}m} > 0.4 {mu}m) and low levels of silicate absorption (s {sub 9.7{mu}m} > -1.0). There is a general trend among the U/LIRGs for both silicate depth and mid-infrared (MIR) slope to increase with increasing L {sub IR}. U/LIRGs in the late to final stages of a merger also have, on average, steeper MIR slopes and higher levels of dust obscuration. Together, these trends suggest that as gas and dust is funneled toward the center of a coalescing merger, the nuclei become more compact and more obscured. As a result, the dust temperature increases also leading to a steeper MIR slope. The sources that depart from these correlations have very low PAH equivalent width (EQW{sub 6.2{mu}m} < 0.1 {mu}m) consistent with their emission being dominated by an active galactic nucleus (AGN) in the MIR. These extremely low PAH EQW sources separate into two distinct types: relatively unobscured sources with a very hot dust component (and thus very shallow MIR slopes) and heavily dust obscured nuclei with a steep temperature gradient. The most heavily dust obscured sources are also the most compact in their MIR

  14. Remote sensing of seawater and drifting ice in Svalbard fjords by compact Raman lidar.

    PubMed

    Bunkin, Alexey F; Klinkov, Vladimir K; Lednev, Vasily N; Lushnikov, Dmitry L; Marchenko, Aleksey V; Morozov, Eugene G; Pershin, Sergey M; Yulmetov, Renat N

    2012-08-01

    A compact Raman lidar system for remote sensing of sea and drifting ice was developed at the Wave Research Center at the Prokhorov General Physics Institute of the Russian Academy of Sciences. The developed system is based on a diode-pumped solid-state YVO(4):Nd laser combined with a compact spectrograph equipped with a gated detector. The system exhibits high sensitivity and can be used for mapping or depth profiling of different parameters within many oceanographic problems. Light weight (∼20 kg) and low power consumption (300 W) make it possible to install the device on any vehicle, including unmanned aircraft or submarine systems. The Raman lidar presented was used for study and analysis of the different influence of the open sea and glaciers on water properties in Svalbard fjords. Temperature, phytoplankton, and dissolved organic matter distributions in the seawater were studied in the Ice Fjord, Van Mijen Fjord, and Rinders Fjord. Drifting ice and seawater in the Rinders Fjord were characterized by the Raman spectroscopy and fluorescence. It was found that the Paula Glacier strongly influences the water temperature and chlorophyll distributions in the Van Mijen Fjord and Rinders Fjord. Possible applications of compact lidar systems for express monitoring of seawater in places with high concentrations of floating ice or near cold streams in the Arctic Ocean are discussed. PMID:22859038

  15. Ground support electronic interface for the ionospheric spectroscopy and atmospheric chemistry (ISAAC) ultraviolet spectrograph. Master`s thesis

    SciTech Connect

    MacQuarrie, J.A.

    1994-12-01

    This thesis details the design and development of an electronic Ground Support Equipment (GSE) interface for the Naval Postgraduate School`s (NPS) Ionospheric Spectroscopy and Atmospheric Chemistry (ISAAC) spectrograph. The ISAAC spectrograph, which was designed at NPS and built by Research Support Instruments, Inc., is intended to observe atmospheric airglow and auroral emissions in the ultraviolet (1800A to 3300A) wavelength region. It is to be included as one of several sensors flown onboard the Advanced Research and Global Observation Satellite (ARGOS), which is scheduled for an early 1996 launch. The GSE was developed in order to allow ground testing and calibration of the instrument prior to and during integration with the satellite bus. The GSE includes hardware to provide the connections between various components of the spectrograph and a Macintosh computer with an installed I/O card. The GSE also includes a user-friendly software interface written with LabVIEW 2.2 that provides the ability to view spectra obtained from the instrument and to remotely control mechanical functions of the spectrograph. An initial wavelength calibration of the spectrograph has been performed using the completed GSE.

  16. Development of a cryogenic system for the VIRUS array of 150 spectrographs for the Hobby-Eberly Telescope

    NASA Astrophysics Data System (ADS)

    Chonis, Taylor S.; Vattiat, Brian L.; Hill, Gary J.; Marshall, J. L.; Cabral, Kris; DePoy, D. L.; Smith, Michael P.; Good, John M.; Booth, John A.; Rafal, Marc D.; Savage, Richard D.

    2010-07-01

    The upcoming Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) has provided motivation for upgrading the Hobby-Eberly Telescope (HET) at the McDonald Observatory. This upgrade includes an increase in the field-of-view to accommodate the new and revolutionary Visible Integral-field Replicable Unit Spectrograph (VIRUS). VIRUS is the instrument designed to conduct the HETDEX survey and consists of 150 individual integral-field spectrographs fed by 33,600 total optical fibers covering the 22 arc-minute field-of-view of the upgraded HET. The spectrographs are mounted in four enclosures, each 6.0×3.0×1.4 meters in size. Each spectrograph contains a CCD detector that must be cryogenically cooled, presenting an interesting cryogenic and vacuum challenge within the distribution system. In this paper, we review the proposed vacuum jacketed, thermal siphon, liquid nitrogen distribution system used to cool the array of detectors and discuss recent developments. We focus on the design, prototyping, and testing of a novel "make-break" thermal connector, built from a modified cryogenic bayonet, that is used to quickly detach a single spectrograph pair from the system.

  17. Developments in simulations and software for a near-infrared precision radial velocity spectrograph

    NASA Astrophysics Data System (ADS)

    Terrien, Ryan C.; Bender, Chad F.; Mahadevan, Suvrath; Halverson, Samuel P.; Ramsey, Lawrence W.; Hearty, Frederick R.

    2014-07-01

    We present developments in simulations and software for the Habitable Zone Planet Finder (HPF), an R~50,000 near-infrared cross-dispersed radial velocity spectrograph that will be used to search for planets around M dwarfs. HPF is fiber-fed, operates in the zYJ bands, and uses a 1.7μm cutoff HAWAII-2RG (H2RG) NIR detector. We have constructed an end-to-end simulator that accepts as input a range of stellar models contaminated with telluric features and processes these through a simulated detector. This simulator accounts for the characteristics of the H2RG, including interpixel capacitance, persistence, nonlinearities, read noise, and other detector characteristics, as measured from our engineering-grade H2RG. It also implements realistic order curvature. We describe applications of this simulator including optimization of the fiber configuration at the spectrograph slit and selection of properties for a laser frequency comb calibration source. The simulator has also provided test images for development of the HPF survey extraction and RV analysis pipeline and we describe progress on this pipeline itself, which will implement optimal extraction, laser frequency comb and emission lamp wavelength calibration, and cross-correlation based RV measurement.

  18. Calibration of high accuracy radial velocity spectrographs: beyond the Th-Ar lamps

    NASA Astrophysics Data System (ADS)

    Wildi, Francois; Pepe, Francesco; Lovis, Christophe; Chazelas, Bruno; Wilken, Tobias; Manescau, Antonio; Pasquini, Luca; Holzwarth, Ronald; Stenimetz, Tilo; Udem, Thomas; Hänsch, Theodor; Lo Curto, Gaspare

    2009-08-01

    Since its first light in 2003, the HARPS radial velocity spectrograph (RVS) has performed exquisitely well on the 3.6m ESO telescope at La Silla Observatory (Chile). It now routinely exhibits a measurement noise of 0.5 m/s or 1.7 10-9 on a relative scale. Despite innovative work by Lovis and colleagues [14] to improve the accuracy obtained with the calibration lamps used, there is evidence that still better performance could be achieved by using more stable wavelength standards. In this paper, we present two methods are aim at overcoming the shortcoming of present day calibrators and that could satisfy the need for a cm/s -level calibrator like we are planning on using on the 2nd generation instruments at the VLT and on the ELT instrumentation. A temperature-stabilized Fabry-Perot interferometer has the promise of being stable to a few cm/s and has very uniform line levels and spacings, while a laser comb has already achieved a precision better than 15 cm/s, despite using only one of the 72 orders of the spectrographs.

  19. Line profile analysis of an astronomical spectrograph with a laser frequency comb

    NASA Astrophysics Data System (ADS)

    Zhao, Fei; Zhao, Gang; Lo Curto, Gaspare; Wang, Hui-Juan; Liu, Yu-Juan; Wang, Liang; Wang, Wei

    2014-08-01

    We present a study of the spectral line shape associated with a High Resolution Spectrograph on the 2.16 m telescope at the Xinglong Observing Station of National Astronomical Observatories, Chinese Academy of Sciences. This measurement is based on modeling the instrumental line shape obtained by unresolved modes from a Yb-fiber mode-locked laser frequency comb. With the current repetition rate of 250 MHz and 26 GHz mode spacing on the spectrograph, we find the absolute variation of the line center, 0.0597 pixel in the direction of the CCDs, and 0.00275 pixel (~3 m s-1) for relative variation in successive exposures on a short timescale. A novel double-Gaussian model is presented to improve the quality of the fit by a factor of 2.47 in a typical single exposure. We also use analysis with raw moments and central moments to characterize the change in line shape across the detector. A trend in charge transfer efficiency can be found on the E2V 4096 × 4096 CCD that provides a correction for wavelength calibration aiming to reach a level of precision for radial velocity below 1 ms-1.

  20. The UV multi-object slit-spectrograph FIREBall-2 simulator

    NASA Astrophysics Data System (ADS)

    Mège, P.; Pascal, S.; Quiret, S.; Corlies, L.; Vibert, D.; Grange, R.; Milliard, B.

    2015-08-01

    The FIREBall-2 Instrument Model (FIREBallIMO) is a piece of software simulating the optical behaviour of the Multi-Object Two-Curved Schmidt Slit Spectograph of FIREBall-2 (Faint Intergalactic Redshifted Emission BALLoon), a balloon-borne telescope (40 km in alt.) designed to perform a direct detection of the faint Circum Galactic Medium (CGM) in emission around low-z galaxies. The spectrograph has been optimized to operate in a narrow UV band [195-225] nanometers, the so-called atmospheric sweet spot, where the sky background presents no emission lines and can be considered approximately flat, a value of 500 continnum units, seen through an optical transmission of 50% at an atmospheric pressure of 3 millibars. This paper gives an overview of the software current modular architecture after a year of productive effort (in terms of parametric model space definition, associated data cubes generation and digital processing) starting from the instrument initial optical model designed under Zemax software to the final 2D-detected image. A special emphasis is put on the design of a cython-wrapped driver able to retrieve dense ray-sampled PSFs out of the Zemax box efficiently. The optical mappings and distortions from the sky to the spectrograph's entrance slit plane and from the sky to the detection plane are presented, as well as some end-to-end simulations leading to Signal-to-Noise Ratio estimates computed on artificial point-like or extended test sources.

  1. MuSICa: the Multi-Slit Image Slicer for the est Spectrograph

    NASA Astrophysics Data System (ADS)

    Calcines, A.; López, R. L.; Collados, M.

    2013-09-01

    Integral field spectroscopy (IFS) is a technique that allows one to obtain the spectra of all the points of a bidimensional field of view simultaneously. It is being applied to the new generation of the largest night-time telescopes but it is also an innovative technique for solar physics. This paper presents the design of a new image slicer, MuSICa (Multi-Slit Image slicer based on collimator-Camera), for the integral field spectrograph of the 4-m aperture European Solar Telescope (EST). MuSICa is a multi-slit image slicer that decomposes an 80 arcsec2 field of view into slices of 50 μm and reorganizes it into eight slits of 0.05 arcsec width × 200 arcsec length. It is a telecentric system with an optical quality at diffraction limit compatible with the two modes of operation of the spectrograph: spectroscopic and spectro-polarimetric. This paper shows the requirements, technical characteristics and layout of MuSICa, as well as other studied design options.

  2. Compatibility of Spatially Coded Apertures with a Miniature Mattauch-Herzog Mass Spectrograph

    NASA Astrophysics Data System (ADS)

    Russell, Zachary E.; DiDona, Shane T.; Amsden, Jason J.; Parker, Charles B.; Kibelka, Gottfried; Gehm, Michael E.; Glass, Jeffrey T.

    2016-04-01

    In order to minimize losses in signal intensity often present in mass spectrometry miniaturization efforts, we recently applied the principles of spatially coded apertures to magnetic sector mass spectrometry, thereby achieving increases in signal intensity of greater than 10× with no loss in mass resolution Chen et al. (J. Am. Soc. Mass Spectrom. 26, 1633-1640, 2015), Russell et al. (J. Am. Soc. Mass Spectrom. 26, 248-256, 2015). In this work, we simulate theoretical compatibility and demonstrate preliminary experimental compatibility of the Mattauch-Herzog mass spectrograph geometry with spatial coding. For the simulation-based theoretical assessment, COMSOL Multiphysics finite element solvers were used to simulate electric and magnetic fields, and a custom particle tracing routine was written in C# that allowed for calculations of more than 15 million particle trajectory time steps per second. Preliminary experimental results demonstrating compatibility of spatial coding with the Mattauch-Herzog geometry were obtained using a commercial miniature mass spectrograph from OI Analytical/Xylem.

  3. Design and realization of the backup field controllers for LAMOST spectrographs

    NASA Astrophysics Data System (ADS)

    Wang, Jianing; Han, Zhongyi; Zeng, Yizhong; Dai, Songxin; Hu, Zhongwen; Zhu, Yongtian; Wang, Lei; Hou, Yonghui

    2012-09-01

    The China-made telescope, LAMOST, consists of 16 Spectrographs to detect stellar spectra via 4000 optical fibers. In each spectroscope, many movable parts work in phase. Those parts are real-time controlled and managed by field controllers based on FPGA. The master control board of controllers currently being used is constructed by Altera's Cyclone II Development Kit. However, now Altera no longer produce such Kits. As the needs for maintenance and improvement, a backup control board is developed, so that once any field controller is broken, another can changed in time to ensure the control system not being interrupted. Using the newer Altera FPGA chip 3C40 as master control chip can minimize the change in the original design frame of the control structure so as to reduce the workload of software and hardware migration. This paper describes the design process of the Spectrographs backup field controller based on Cyclone 3C40 and gives the problems and solutions encountered during migration for controller hardware and software. The improved field controller not only retains the original controller functions, but also can serve for more motors and sensors due to the increase of input and output pins. Besides, no commodity supply limits, which saves expenses. The FPGA-field controller can also be used in other telescopes, astronomical instruments and industrial control systems as well.

  4. Compatibility of Spatially Coded Apertures with a Miniature Mattauch-Herzog Mass Spectrograph.

    PubMed

    Russell, Zachary E; DiDona, Shane T; Amsden, Jason J; Parker, Charles B; Kibelka, Gottfried; Gehm, Michael E; Glass, Jeffrey T

    2016-04-01

    In order to minimize losses in signal intensity often present in mass spectrometry miniaturization efforts, we recently applied the principles of spatially coded apertures to magnetic sector mass spectrometry, thereby achieving increases in signal intensity of greater than 10× with no loss in mass resolution Chen et al. (J. Am. Soc. Mass Spectrom. 26, 1633-1640, 2015), Russell et al. (J. Am. Soc. Mass Spectrom. 26, 248-256, 2015). In this work, we simulate theoretical compatibility and demonstrate preliminary experimental compatibility of the Mattauch-Herzog mass spectrograph geometry with spatial coding. For the simulation-based theoretical assessment, COMSOL Multiphysics finite element solvers were used to simulate electric and magnetic fields, and a custom particle tracing routine was written in C# that allowed for calculations of more than 15 million particle trajectory time steps per second. Preliminary experimental results demonstrating compatibility of spatial coding with the Mattauch-Herzog geometry were obtained using a commercial miniature mass spectrograph from OI Analytical/Xylem. PMID:26744293

  5. X-shooter near-IR spectrograph arm: design and manufacturing methods

    NASA Astrophysics Data System (ADS)

    Navarro, Ramon; Elswijk, Eddy; de Haan, Menno; Hanenburg, Hiddo; ter Horst, Rik; Kleszcz, Pawel; Kragt, Jan; Pragt, Johan; Rigal, Florence; Roelfsema, Ronald; Schoenmaker, Ton; Tromp, Niels; Venema, Lars; Groot, Paul; Kaper, Lex

    2006-06-01

    X-shooter, the first 2nd generation VLT instrument, is a new high-efficiency echelle spectrograph. X-shooter operates at the Cassegrain focus and covers an exceptionally wide spectral range from 300 to 2500 nm in a single exposure, with an intermediate spectral resolving power R~5000. The instrument consists of a central structure and three prism cross-dispersed echelle spectrographs optimized for the UV-blue, visible and near-IR wavelength ranges. The design of the near-IR arm of the X-shooter instrument employs advanced design methods and manufacturing techniques. Integrated system design is done at cryogenic working temperatures, aiming for an almost alignment-free integration. ASTRON Extreme Light Weighting is used for high stiffness at low mass. Bare aluminium is post-polished to optical quality mirrors, preserving high shape accuracy at cryogenic conditions. Cryogenic optical mounts compensate for CTE differences of various materials, while ensuring high thermal contact. This paper addresses the general design and the application of these specialized techniques.

  6. Introducing CUBES: the Cassegrain U-band Brazil-ESO spectrograph

    NASA Astrophysics Data System (ADS)

    Bristow, Paul; Barbuy, Beatriz; Macanhan, Vanessa B.; Castilho, Bruno; Dekker, Hans; Delabre, Bernard; Diaz, Marcos; Gneiding, Clemens; Kerber, Florian; Kuntschner, Harald; La Mura, Giovanni; Reiss, Roland; Vernet, J.

    2014-07-01

    CUBES is a high-efficiency, medium-resolution (R ≃ 20, 000) spectrograph dedicated to the "ground based UV" (approximately the wavelength range from 300 to 400nm) destined for the Cassegrain focus of one of ESO's VLT unit telescopes in 2018/19. The CUBES project is a joint venture between ESO and Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG) at the Universidade de São Paulo and the Brazilian Laboratório Nacional de Astrofísica (LNA). CUBES will provide access to a wealth of new and relevant information for stellar as well as extra-galactic sources. Principle science cases include the study of heavy elements in metal-poor stars, the direct determination of carbon, nitrogen and oxygen abundances by study of molecular bands in the UV range and the determination of the Beryllium abundance as well as the study of active galactic nuclei and the inter-galactic medium. With a streamlined modern instrument design, high efficiency dispersing elements and UV-sensitive detectors, it will enable a significant gain in sensitivity over existing ground based medium-high resolution spectrographs enabling vastly increased sample sizes accessible to the astronomical community. We present here a brief overview of the project, introducing the science cases that drive the design and discussing the design options and technological challenges.

  7. Spectrographic temperature measurement of a high power breakdown arc in a high pressure gas switch.

    PubMed

    Yeckel, Christopher; Curry, Randy

    2011-09-01

    A procedure for obtaining an approximate temperature value of conducting plasma generated during self-break closure of a RIMFIRE gas switch is described. The plasma is in the form of a breakdown arc which conducts approximately 12 kJ of energy in 1 μs. A spectrographic analysis of the trigger-section of the 6-MV RIMFIRE laser triggered gas switch used in Sandia National Laboratory's "Z-Machine" has been made. It is assumed that the breakdown plasma has sufficiently approached local thermodynamic equilibrium allowing a black-body temperature model to be applied. This model allows the plasma temperature and radiated power to be approximated. The gas dielectric used in these tests was pressurized SF(6). The electrode gap is set at 4.59 cm for each test. The electrode material is stainless steel and insulator material is poly(methyl methacrylate). A spectrum range from 220 to 550 nanometers has been observed and calibrated using two spectral irradiance lamps and three spectrograph gratings. The approximate plasma temperature is reported. PMID:21974578

  8. Spectrographic temperature measurement of a high power breakdown arc in a high pressure gas switch

    SciTech Connect

    Yeckel, Christopher; Curry, Randy

    2011-09-15

    A procedure for obtaining an approximate temperature value of conducting plasma generated during self-break closure of a RIMFIRE gas switch is described. The plasma is in the form of a breakdown arc which conducts approximately 12 kJ of energy in 1 {mu}s. A spectrographic analysis of the trigger-section of the 6-MV RIMFIRE laser triggered gas switch used in Sandia National Laboratory's ''Z-Machine'' has been made. It is assumed that the breakdown plasma has sufficiently approached local thermodynamic equilibrium allowing a black-body temperature model to be applied. This model allows the plasma temperature and radiated power to be approximated. The gas dielectric used in these tests was pressurized SF{sub 6}. The electrode gap is set at 4.59 cm for each test. The electrode material is stainless steel and insulator material is poly(methyl methacrylate). A spectrum range from 220 to 550 nanometers has been observed and calibrated using two spectral irradiance lamps and three spectrograph gratings. The approximate plasma temperature is reported.

  9. The Fiber Multi-object Spectrograph (FMOS) Project: the Anglo-Australian Observatory role

    NASA Astrophysics Data System (ADS)

    Gillingham, Peter R.; Moore, Anna M.; Akiyama, Masayuki; Brzeski, Jurek; Correll, David; Dawson, John; Farrell, Tony J.; Frost, Gabriella; Griesbach, Jason S.; Haynes, Roger; Jones, Damien; Miziarski, Stan; Muller, Rolf; Smedley, Scott; Smith, Greg; Waller, Lew G.; Noakes, Katie; Arridge, Chris

    2003-03-01

    The Fiber Multi-Object Spectrograph (FMOS) project is an Australia-Japan-UK collaboration to design and build a novel 400 fiber positioner feeding two near infrared spectrographs from the prime focus of the Subaru telescope. The project comprises several parts. Those under design and construction at the Anglo-Australian Observatory (AAO) are the piezoelectric actuator driven fiber positioner (Echidna), a wide field (30 arcmin) corrector and a focal plane imager (FPI) used for controlling the positioner and for field acquisition. This paper presents an overview of the AAO share of the FMOS project. It describes the technical infrastructure required to extend the single Echidna "spine" design to a fully functioning multi-fiber instrument, capable of complete field reconfiguration in less than ten minutes. The modular Echidna system is introduced, wherein the field of view is populated by 12 identical rectangular modules, each positioning 40 science fibers and 2 guide fiber bundles. This arrangement allows maintenance by exchanging modules and minimizes the difficulties of construction. The associated electronics hardware, in itself a significant challenge, includes a 23 layer PCB board, able to supply current to each piezoelectric element in the module. The FPI is a dual purpose imaging system translating in two coordinates and is located beneath the assembled modules. The FPI measures the spine positions as well as acquiring sky images for instrument calibration and for field acquisition. An overview of the software is included.

  10. MUSE: A Second-Generation Integral-Field Spectrograph for the VLT

    NASA Astrophysics Data System (ADS)

    McDermid, R. M.; Bacon, R.; Bauer, S.; Boehm, P.; Boudon, D.; Brau-Nogué, S.; Caillier, P.; Capoani, L.; Carollo, C. M.; Champavert, N.; Contini, T.; Daguisé, E.; Delabre, B.; Devriendt, J.; Dreizler, S.; Dubois, J.; Dupieux, M.; Dupin, J. P.; Emsellem, E.; Ferruit, P.; Franx, M.; Gallou, G.; Gerssen, J.; Guiderdoni, B.; Hahn, T.; Hofmann, D.; Jarno, A.; Kelz, A.; Koehler, C.; Kollatschny, W.; Kosmalski, J.; Laurent, F.; Lilly, S. J.; Lizon, J. L.; Loupias, M.; Manescau, A.; Monstein, C.; Nicklas, H.; Parès, L.; Pasquini, L.; Pécontal-Rousset, A.; Pécontal, E.; Pello, R.; Petit, C.; Picat, J.-P.; Popow, E.; Quirrenbach, A.; Reiss, R.; Renault, E.; Roth, M.; Schaye, J.; Soucail, G.; Steinmetz, M.; Stroebele, S.; Stuik, R.; Weilbacher, P.; Wisotzki, L.; Wozniak, H.; de Zeeuw, P. T.

    The Multi Unit Spectroscopic Explorer (MUSE) is a second-generation instrument in development for the Very Large Telescope (VLT) of the European Southern Observatory (ESO), due to begin operation in 2011/12. MUSE will be an extremely powerful integral-field spectrograph fed by a new multiple-laser adaptive optics system on the VLT. In its usual operating mode, MUSE will, in a single observation, produce a 3-dimensional data cube consisting of 90,000 R 3000 spectra, each covering a full spectral octave (480-930 nm), and fully sampling a contiguous 1×1 arcmin2 field with 0.2×0.2 arcsec2 apertures. A high-resolution mode will increase the spatial sampling to 0.025 arcsec per pixel. MUSE is built around a novel arrangement of 24 identical spectrographs (each comparable to a 1st generation VLT instrument), which are fed by a set of 24 precision image slicers. MUSE is designed for stability, with only 2 modes, and virtually no moving parts, allowing very long exposures to be accumulated. Together with high throughput, this ensures that MUSE will have extreme sensitivity for observing faint objects. We overview the technical and scientific aspects of MUSE, highlighting the key challenges for dealing with the unprecedented quantity and complexity of the data, and the integration with the VLT adaptive optics facility (AOF) - a key development on the path to extremely large telescopes (ELTs).

  11. OBSERVATIONS OF OUTFLOWING ULTRAVIOLET ABSORBERS IN NGC 4051 WITH THE COSMIC ORIGINS SPECTROGRAPH

    SciTech Connect

    Kraemer, S. B.; Crenshaw, D. M.; Fischer, T. C.; Dunn, J. P.; Turner, T. J.; Lobban, A. P.; Reeves, J. N.; Miller, L.; Braito, V.

    2012-06-01

    We present new Hubble Space Telescope (HST)/Cosmic Origins Spectrograph (COS) observations of the narrow-line Seyfert 1 galaxy NGC 4051. These data were obtained as part of a coordinated observing program including X-ray observations with the Chandra/High Energy Transmission Grating (HETG) spectrometer and Suzaku. We detected nine kinematic components of UV absorption, which were previously identified using the HST/Space Telescope Imaging Spectrograph (STIS). None of the absorption components showed evidence for changes in column density or profile within the {approx}10 yr between the STIS and COS observations, which we interpret as evidence of (1) saturation, for the stronger components, or (2) very low densities, i.e., n{sub H} < 1 cm{sup -3}, for the weaker components. After applying a +200 km s{sup -1} offset to the HETG spectrum, we found that the radial velocities of the UV absorbers lay within the O VII profile. Based on photoionization models, we suggest that, while UV components 2, 5, and 7 produce significant O VII absorption, the bulk of the X-ray absorption detected in the HETG analysis occurs in more highly ionized gas. Moreover, the mass-loss rate is dominated by high-ionization gas which lacks a significant UV footprint.

  12. The Goddard Integral Field Spectrograph at Apache Point Observatory: Current Status and Progress Towards Photon Counting

    NASA Astrophysics Data System (ADS)

    McElwain, Michael W.; Grady, Carol A.; Bally, John; Brinkmann, Jonathan V.; Bubeck, James; Gong, Qian; Hilton, George M.; Ketzeback, William F.; Lindler, Don; Llop Sayson, Jorge; Malatesta, Michael A.; Norton, Timothy; Rauscher, Bernard J.; Rothe, Johannes; Straka, Lorrie; Wilkins, Ashlee N.; Wisniewski, John P.; Woodgate, Bruce E.; York, Donald G.

    2015-01-01

    We present the current status and progress towards photon counting with the Goddard Integral Field Spectrograph (GIFS), a new instrument at the Apache Point Observatory's ARC 3.5m telescope. GIFS is a visible light imager and integral field spectrograph operating from 400-1000 nm over a 2.8' x 2.8' and 14' x 14' field of view, respectively. As an IFS, GIFS obtains over 1000 spectra simultaneously and its data reduction pipeline reconstructs them into an image cube that has 32 x 32 spatial elements and more than 200 spectral channels. The IFS mode can be applied to a wide variety of science programs including exoplanet transit spectroscopy, protostellar jets, the galactic interstellar medium probed by background quasars, Lyman-alpha emission line objects, and spectral imaging of galactic winds. An electron-multiplying CCD (EMCCD) detector enables photon counting in the high spectral resolution mode to be demonstrated at the ARC 3.5m in early 2015. The EMCCD work builds upon successful operational and characterization tests that have been conducted in the IFS laboratory at NASA Goddard. GIFS sets out to demonstrate an IFS photon-counting capability on-sky in preparation for future exoplanet direct imaging missions such as the AFTA-Coronagraph, Exo-C, and ATLAST mission concepts. This work is supported by the NASA APRA program under RTOP 10-APRA10-0103.

  13. Conceptual Design of the Coronagraphic High Angular Resolution Imaging Spectrograph (CHARIS) for the Subaru Telescope

    NASA Technical Reports Server (NTRS)

    Peters, Mary Anne; Groff, Tyler; Kasdin, N. Jeremy; McElwain, Michael W.; Galvin, Michael; Carr, Michael A.; Lupton, Robert; Gunn, James E.; Knapp, Gillian; Gong, Qian; Carlotti, Alexis; Brandt, Timothy; Janson, Markus; Guyon, Olivier; Martinache, Frantz; Hayashi, Masahiko; Takato, Naruhisa

    2012-01-01

    Recent developments in high-contrast imaging techniques now make possible both imaging and spectroscopy of planets around nearby stars. We present the conceptual design of the Coronagraphic High Angular Resolution Imaging Spectrograph (CHARIS), a lenslet-based, cryogenic integral field spectrograph (IFS) for imaging exoplanets on the Subaru telescope. The IFS will provide spectral information for 140 x 140 spatial elements over a 1.75 arcsecs x 1.75 arcsecs field of view (FOV). CHARIS will operate in the near infrared (lambda = 0.9 - 2.5 micron) and provide a spectral resolution of R = 14, 33, and 65 in three separate observing modes. Taking advantage of the adaptive optics systems and advanced coronagraphs (AO188 and SCExAO) on the Subaru telescope, CHARIS will provide sufficient contrast to obtain spectra of young self-luminous Jupiter-mass exoplanets. CHARIS is in the early design phases and is projected to have first light by the end of 2015. We report here on the current conceptual design of CHARIS and the design challenges.

  14. A Microshutter-Based Field Selector for JWST's Near Infared Spectrograph

    NASA Technical Reports Server (NTRS)

    Silvergerg, Rorbert F.; Arendt, Richard; Franz, David; Jhabvala, Murzy; Kletetschka, Gunther; Kutyrev, Alexander; Li, Mary; Moseley, Samuel H.; Rapchun, David; Snodgrass, Stephen; Sohl, David; Spa, Leroy

    2007-01-01

    One of the James Webb Space Telescope's (JWST) primary science goals is to characterize the epoch of galaxy formation in the universe and observe the first galaxies and clusters of galaxies. This goal requires multi-band imaging and spectroscopic data in the near infrared portion of the spectrum for large numbers of very faint galaxies. Because such objects are sparse on the sky at the JWST resolution, a multi-object spectrograph is necessary to efficiently carry out the required observations. We have developed a fully programmable microshutter array that will be used as the field selector for the Near Infrared Spectrograph (NIRSpec) on JWST. This device allows slits to be opened at the locations of selected galaxies in the field of view while blocking other unwanted light from the sky background and bright sources. In practice, greater than 100 objects within the field of view will be observed simultaneously. In this paper, we describe the microshutter arrays, their development, fabrication, testing, and progress toward delivery of flight qualified devices to the NIRSpec instrument team in 2008.

  15. Conditional-sampling spectrograph detection system for fluorescence measurements of individual airborne biological particles.

    PubMed

    Nachman, P; Chen, G; Pinnick, R G; Hill, S C; Chang, R K; Mayo, M W; Fernandez, G L

    1996-03-01

    We report the design and operation of a prototype conditional-sampling spectrograph detection system that can record the fluorescence spectra of individual, micrometer-sized aerosols as they traverse an intense 488-nm intracavity laser beam. The instrument's image-intensified CCD detector is gated by elastic scattering or by undispersed fluorescence from particles that enter the spectrograph's field of view. It records spectra only from particles with preselected scattering-fluorescence levels (a fiber-optic-photomultiplier subsystem provides the gating signal). This conditional-sampling procedure reduces data-handling rates and increases the signal-to-noise ratio by restricting the system's exposures to brief periods when aerosols traverse the beam. We demonstrate these advantages by reliably capturing spectra from individual fluorescent microspheres dispersed in an airstream. The conditional-sampling procedure also permits some discrimination among different types of particles, so that spectra may be recorded from the few interesting particles present in a cloud of background aerosol. We demonstrate such discrimination by measuring spectra from selected fluorescent microspheres in a mixture of two types of microspheres, and from bacterial spores in a mixture of spores and nonfluorescent kaolin particles. PMID:21085216

  16. Spectrographic measures of the speech of young children with cleft lip and cleft palate.

    PubMed

    Casal, C; Domínguez, C; Fernández, A; Sarget, R; Martínez-Celdrán, E; Sentís-Vilalta, J; Gay-Escoda, C

    2002-01-01

    Twenty-two consecutive children with repaired cleft lip and/or palate [isolated cleft lip (CL) 6, isolated cleft palate (CP) 7, unilateral cleft lip and palate (UCLP) 7, and bilateral cleft lip and palate 2] with a mean age of 27 months underwent spectrographic measures of tape-recorded speech (DSP Sona-Graph digital unit). Controls were 22 age- and sex-matched noncleft children. Data analyzed included (1) the Spanish vocalic variables [a, i, u, e, o]: first formant, second formant, duration, and context; (2) obstruent variables [p, t, k]: burst, voice onset time, and duration, and (3) nasal variables [m]: first formant, second formant, and duration. Statistically significant differences were observed between the CL group and the control group in the first formant of [e] and in the increase of the frequency of the [t] burst. Comparison between UCLP and controls showed differences in the second formant of [a], in the first formant of [o], and in the second formant of [o]. These results suggest a small but significant influence of either the cleft lip or its repair on lip rounding for [o] and [u]. In addition, tongue position differences were most likely responsible for the differences seen with [a] and [e]. Spectrographic differences in the current patients did not contribute to meaningful differences in speech sound development. Individualized care (orthodontics, surgery, speech therapy) in children with cleft lip and/or palate attended at specialized craniofacial units contributes to normalization of speech development. PMID:12378036

  17. Invariant distributions on compact homogeneous spaces

    SciTech Connect

    Gorbatsevich, V V

    2013-12-31

    In this paper, we study distributions on compact homogeneous spaces, including invariant distributions and also distributions admitting a sub-Riemannian structure. We first consider distributions of dimension 1 and 2 on compact homogeneous spaces. After this, we study the cases of compact homogeneous spaces of dimension 2, 3, and 4 in detail. Invariant distributions on simply connected compact homogeneous spaces are also treated. Bibliography: 18 titles.

  18. Powder compaction in systems of bimodal distribution

    NASA Technical Reports Server (NTRS)

    Chattopadhyay, A. K.; Whittemore, O. J., Jr.

    1973-01-01

    The compaction of mixtures involving different particle sizes is discussed. The various stages of the compaction process include the rearrangement of particles, the filling of the interstices of the large particles by the smaller ones, and the change in particle size and shape upon further densification through the application of pressure. Experimental approaches and equipment used for compacting material are discussed together with the theoretical relations of the compacting process.

  19. Rapid compaction during RNA folding

    NASA Astrophysics Data System (ADS)

    Russell, Rick; Millett, Ian S.; Tate, Mark W.; Kwok, Lisa W.; Nakatani, Bradley; Gruner, Sol M.; Mochrie, Simon G. J.; Pande, Vijay; Doniach, Sebastian; Herschlag, Daniel; Pollack, Lois

    2002-04-01

    We have used small angle x-ray scattering and computer simulations with a coarse-grained model to provide a time-resolved picture of the global folding process of the Tetrahymena group I RNA over a time window of more than five orders of magnitude. A substantial phase of compaction is observed on the low millisecond timescale, and the overall compaction and global shape changes are largely complete within one second, earlier than any known tertiary contacts are formed. This finding indicates that the RNA forms a nonspecifically collapsed intermediate and then searches for its tertiary contacts within a highly restricted subset of conformational space. The collapsed intermediate early in folding of this RNA is grossly akin to molten globule intermediates in protein folding.

  20. LEMUR (Large European Module for solar Ultraviolet Research): a VUV imaging spectrograph for the JAXA Solar-C Mission

    NASA Astrophysics Data System (ADS)

    Korendyke, Clarence M.; Teriaca, Luca; Doschek, George A.; Harra, Louise K.; Schühle, Udo H.; Shimizu, Toshifumi

    2011-10-01

    LEMUR is a VUV imaging spectrograph with 0.28" resolution. Incident solar radiation is imaged onto the spectrograph slit by a single mirror telescope consisting of a 30-cm steerable f/12 off-axis paraboloid mirror. The spectrograph slit is imaged and dispersed by a highly corrected grating that focuses the solar spectrum over the detectors. The mirror is coated with a suitable multilayer with B4C top-coating providing a reflectance peak around 18.5 nm besides the usual B4C range above 500Å. The grating is formed by two halves, one optimized for performances around 185Å and the other above 500Å. Three intensified CCD cameras will record spectra above 50 nm while a large format CCD array with an aluminum filter will be used around 185Å.

  1. FMOS the fibre multiple-object spectrograph, part VIII: current performances and results of the engineering observations

    NASA Astrophysics Data System (ADS)

    Kimura, Masahiko; Akiyama, Masayuki; Dalton, Gavin B.; Iwamuro, Fumihide; Lewis, Ian J.; Maihara, Toshinori; Ohta, Kouji; Tait, Philip; Takato, Naruhisa; Tamura, Naoyuki; Tosh, Ian A. J.; Smedley, Scott; Curtis Lake, Emma; Inagaki, Takeshi; Jeschke, Eric; Kawate, Kaori; Moritani, Yuuki; Sumiyoshi, Masanao; Yabe, Kiyoto

    2010-07-01

    The Fibre Multi-Object Spectrograph for Subaru Telescope (FMOS) is a near-infrared instrument with 400 fibres in a 30' filed of view at F/2 prime focus. To observe 400 objects simultaneously, we have developed a fibre positioner called "Echidna" using a tube piezo actuator. We have also developed two OH-airglow suppressed and refrigerated spectrographs. Each spectrograph has two spectral resolution modes: the low-resolution mode and the high-resolution mode. The low-resolution mode covers the complete wavelength range of 0.9 - 1.8 μm with one exposure, while the high-resolution mode requires four exposures at different camera positions to cover the full wavelength range. The first light was accomplished in May 2008. The science observations and the open-use observations begin in May 2010.

  2. Double-channel crystal spectrograph for measuring plasma x-ray in the 1.33-2.46-nm region

    NASA Astrophysics Data System (ADS)

    Xiong, Xiancai; Zhong, Xianxin; Xiao, Shali; Chen, Yu; Yang, Guohong; Gao, Jie

    2004-10-01

    In order to measure laser-produced plasma x-ray in the 1.33-2.46-nm region, an elliptical crystal spectrograph has been designed and fabricated. The potassium acid phthalate (KAP) crystal with a 2d spacing of 2.663 nm is used as the x-ray dispersive element, it is elliptically bent and glued on a rustless-steel substrate with a 0.9586 eccentricity and a 1350-mm focal distance. The spectrograph is equipped with an x-ray charge-coupled device (CCD) camera for recording the space-resolved spectrum on one port, and an x-ray streak camera for recording the time-resolved spectrum on another port. The first testing experiment was carried out on the XG-2 target chamber, the experimental results demonstrate that the spectral resolution is about 640 for this spectrograph.

  3. Nuclear Physics for Compact Stars

    SciTech Connect

    Baldo, M.

    2009-05-04

    A brief overview is given of the different lines of research developed under the INFN project 'Compact Stellar Objects and Dense Hadronic Matter' (acronym CT51). The emphasis of the project is on the structure of Neutron Stars (NS) and related objects. Starting from crust, the different Nuclear Physics problems are described which are encountered going inside a NS down to its inner core. The theoretical challenges and the observational inputs are discussed in some detail.

  4. Compact magnetic energy storage module

    DOEpatents

    Prueitt, Melvin L.

    1994-01-01

    A superconducting compact magnetic energy storage module in which a plurality of superconducting toroids, each having a toroidally wound superconducting winding inside a poloidally wound superconducting winding, are stacked so that the flow of electricity in each toroidally wound superconducting winding is in a direction opposite from the direction of electrical flow in other contiguous superconducting toroids. This allows for minimal magnetic pollution outside of the module.

  5. Compact planar microwave blocking filters

    NASA Technical Reports Server (NTRS)

    U-Yen, Kongpop (Inventor); Wollack, Edward J. (Inventor)

    2012-01-01

    A compact planar microwave blocking filter includes a dielectric substrate and a plurality of filter unit elements disposed on the substrate. The filter unit elements are interconnected in a symmetrical series cascade with filter unit elements being organized in the series based on physical size. In the filter, a first filter unit element of the plurality of filter unit elements includes a low impedance open-ended line configured to reduce the shunt capacitance of the filter.

  6. Compact portable diffraction moire interferometer

    DOEpatents

    Deason, V.A.; Ward, M.B.

    1988-05-23

    A compact and portable moire interferometer used to determine surface deformations of an object. The improved interferometer is comprised of a laser beam, optical and fiber optics devices coupling the beam to one or more evanescent wave splitters, and collimating lenses directing the split beam at one or more specimen gratings. Observations means including film and video cameras may be used to view and record the resultant fringe patterns. 7 figs.

  7. Compact portable diffraction moire interferometer

    DOEpatents

    Deason, Vance A.; Ward, Michael B.

    1989-01-01

    A compact and portable moire interferometer used to determine surface deformations of an object. The improved interferometer is comprised of a laser beam, optical and fiber optics devices coupling the beam to one or more evanescent wave splitters, and collimating lenses directing the split beam at one or more specimen gratings. Observation means including film and video cameras may be used to view and record the resultant fringe patterns.

  8. Compact color schlieren optical system.

    PubMed

    Buchele, D R; Griffin, D W

    1993-08-01

    A compact optical system for use with rainbow schlieren deflectometry is described. Both halves of the optical system consist of well-corrected telescopes whose refractive elements are all from manufacturer's stock catalogs, with the reflective primary being a spherical surface. As a result, the system is relatively easy to construct and meets the requirement of long focal length for quantitative rainbow schlieren measurements. PMID:20830072

  9. Compact Color Schlieren Optical System

    NASA Technical Reports Server (NTRS)

    Buchele, Donald R.; Griffin, Devon W.

    1996-01-01

    Compact, rugged optical system developed for use in rainbow schlieren deflectometry. Features unobscured telescope with focal-length/aperture-width ratio of 30. Made of carefully selected but relatively inexpensive parts. All of lenses stock items. By-product of design is optical system with loose tolerances on interlens spacing. One of resulting advantages, insensitivity to errors in fabrication of optomechanical mounts. Another advantage is ability to compensate for some of unit-to-unit variations inherent in stock lenses.

  10. Compact magnetic energy storage module

    DOEpatents

    Prueitt, M.L.

    1994-12-20

    A superconducting compact magnetic energy storage module in which a plurality of superconducting toroids, each having a toroidally wound superconducting winding inside a poloidally wound superconducting winding, are stacked so that the flow of electricity in each toroidally wound superconducting winding is in a direction opposite from the direction of electrical flow in other contiguous superconducting toroids. This allows for minimal magnetic pollution outside of the module. 4 figures.

  11. Thixoforming of Stellite Powder Compacts

    SciTech Connect

    Hogg, S. C.; Atkinson, H. V.; Kapranos, P.

    2007-04-07

    Thixoforming involves processing metallic alloys in the semi-solid state. The process requires the microstructure to be spheroidal when part-solid and part-liquid i.e. to consist of solid spheroids surrounded by liquid. The aim of this work was to investigate whether powder compacts can be used as feedstock for thixoforming and whether the consolidating pressure in the thixoformer can be used to remove porosity from the compact. The powder compacts were made from stellite 6 and stellite 21 alloys, cobalt-based alloys widely used for e.g. manufacturing prostheses. Isothermal heat treatments of small samples in the consolidated state showed the optimum thixoforming temperature to be in the range 1340 deg. C-1350 deg. C for both materials. The alloys were thixoformed into graphite dies and flowed easily to fill the die. Porosity in the thixoformed components was lower than in the starting material. Hardness values at various positions along the radius of the thixoformed demonstrator component were above the specification for both alloys.

  12. Compact Stellarator Path to DEMO

    NASA Astrophysics Data System (ADS)

    Lyon, J. F.

    2007-11-01

    Issues for a DEMO reactor are sustaining an ignited/high-Q plasma in steady state, avoiding disruptions and large variations in power flux to the wall, adequate confinement of thermal plasma and alpha-particles, control of a burning plasma, particle and power handling, etc. Compact stellarators have key advantages -- steady-state high-plasma-density operation without external current drive or disruptions, stability without a close conducting wall or active feedback systems, and low recirculating power -- in addition to moderate plasma aspect ratio, good confinement, and high-beta potential. The ARIES-CS study established that compact stellarators can be competitive with tokamaks as reactors. Many of the issues for a compact stellarator DEMO can be answered using results from large tokamaks, ITER D-T experiments and fusion materials, technology and component development programs, in addition to stellarators in operation, under construction or in development. However, a large next-generation stellarator will be needed to address some physics issues: size scaling and confinement at higher parameters, burning plasma issues, and operation with a strongly radiative divertor. Technology issues include simpler coils, structure, and divertor fabrication, and better cost information.

  13. Compaction Waves in Granular HMX

    SciTech Connect

    E. Kober; R. Menikoff

    1999-01-01

    Piston driven compaction waves in granular HMX are simulated with a two-dimensional continuum mechanics code in which individual grains are resolved. The constitutive properties of the grains are modeled with a hydrostatic pressure and a simple elastic-plastic model for the shear stress. Parameters are chosen to correspond to inert HMX. For a tightly packed random grain distribution (with initial porosity of 19%) we varied the piston velocity to obtain weak partly compacted waves and stronger fully compacted waves. The average stress and wave speed are compatible with the porous Hugoniot locus for uni- axial strain. However, the heterogeneities give rise to stress concentrations, which lead to localized plastic flow. For weak waves, plastic deformation is the dominant dissipative mechanism and leads to dispersed waves that spread out in time. In addition to dispersion, the granular heterogeneities give rise to subgrain spatial variation in the thermodynamic variables. The peaks in the temperature fluctuations, known as hot spots, are in the range such that they are the critical factor for initiation sensitivity.

  14. Strings in compact cosmological spaces

    NASA Astrophysics Data System (ADS)

    Craps, Ben; Evnin, Oleg; Konechny, Anatoly

    2013-10-01

    We confront the problem of giving a fundamental definition to perturbative string theory in spacetimes with totally compact space (taken to be a torus for simplicity, though the nature of the problem is very general) and non-compact time. Due to backreaction induced by the presence of even a single string quantum, the usual formulation of perturbative string theory in a fixed classical background is infrared-divergent at all subleading orders in the string coupling, and needs to be amended. The problem can be seen as a closed string analogue of D0-brane recoil under an impact by closed strings (a situation displaying extremely similar infrared divergences). Inspired by the collective coordinate treatment of the D0-brane recoil, whereby the translational modes of the D0-brane are introduced as explicit dynamical variables in the path integral, we construct a similar formalism for the case of string-induced gravitational backreaction, in which the spatially uniform modes of the background fields on the compact space are quantized explicitly. The formalism can equally well be seen as an ultraviolet completion of a minisuperspace quantum cosmology with string degrees of freedom. We consider the amplitudes for the universe to have two cross-sections with specified spatial properties and string contents, and show (at the first non-trivial order) that they are finite within our formalism.

  15. Thixoforming of Stellite Powder Compacts

    NASA Astrophysics Data System (ADS)

    Hogg, S. C.; Atkinson, H. V.; Kapranos, P.

    2007-04-01

    Thixoforming involves processing metallic alloys in the semi-solid state. The process requires the microstructure to be spheroidal when part-solid and part-liquid i.e. to consist of solid spheroids surrounded by liquid. The aim of this work was to investigate whether powder compacts can be used as feedstock for thixoforming and whether the consolidating pressure in the thixoformer can be used to remove porosity from the compact. The powder compacts were made from stellite 6 and stellite 21 alloys, cobalt-based alloys widely used for e.g. manufacturing prostheses. Isothermal heat treatments of small samples in the consolidated state showed the optimum thixoforming temperature to be in the range 1340°C-1350°C for both materials. The alloys were thixoformed into graphite dies and flowed easily to fill the die. Porosity in the thixoformed components was lower than in the starting material. Hardness values at various positions along the radius of the thixoformed demonstrator component were above the specification for both alloys.

  16. Label transfer by measuring compactness.

    PubMed

    Varga, Robert; Nedevschi, Sergiu

    2013-12-01

    This paper presents a new automatic image annotation algorithm. First, we introduce a new similarity measure between images: compactness. This uses low level visual descriptors for determining the similarity between two images. Compactness shows how close test image features lie to training image feature cluster centers. The measure provides the core for a k-nearest neighbor type image annotation method. Afterward, a formalism for defining different transfer techniques is devised and several label transfer techniques are provided. The method as whole is evaluated on four image annotation benchmarks. The results on these sets validate the accuracy of the approach, which outperforms many state-of-the-art annotation methods. The method presented here requires a simple training process, efficiently combines different feature types and performs better than complex learning algorithms, even in this incipient form. The main contributions of this paper are the usage of compactness as a similarity measure that enables efficient low level feature comparison and an annotation algorithm based on label transfer. PMID:23955754

  17. THE MULTI-OBJECT, FIBER-FED SPECTROGRAPHS FOR THE SLOAN DIGITAL SKY SURVEY AND THE BARYON OSCILLATION SPECTROSCOPIC SURVEY

    SciTech Connect

    Smee, Stephen A.; Barkhouser, Robert H.; Gunn, James E.; Carr, Michael A.; Lupton, Robert H.; Loomis, Craig; Uomoto, Alan; Roe, Natalie; Schlegel, David; Rockosi, Constance M.; Leger, French; Owen, Russell; Anderson, Lauren; Dawson, Kyle S.; Olmstead, Matthew D.; Brinkmann, Jon; Long, Dan; Honscheid, Klaus; Harding, Paul; Annis, James; and others

    2013-08-01

    We present the design and performance of the multi-object fiber spectrographs for the Sloan Digital Sky Survey (SDSS) and their upgrade for the Baryon Oscillation Spectroscopic Survey (BOSS). Originally commissioned in Fall 1999 on the 2.5 m aperture Sloan Telescope at Apache Point Observatory, the spectrographs produced more than 1.5 million spectra for the SDSS and SDSS-II surveys, enabling a wide variety of Galactic and extra-galactic science including the first observation of baryon acoustic oscillations in 2005. The spectrographs were upgraded in 2009 and are currently in use for BOSS, the flagship survey of the third-generation SDSS-III project. BOSS will measure redshifts of 1.35 million massive galaxies to redshift 0.7 and Ly{alpha} absorption of 160,000 high redshift quasars over 10,000 deg{sup 2} of sky, making percent level measurements of the absolute cosmic distance scale of the universe and placing tight constraints on the equation of state of dark energy. The twin multi-object fiber spectrographs utilize a simple optical layout with reflective collimators, gratings, all-refractive cameras, and state-of-the-art CCD detectors to produce hundreds of spectra simultaneously in two channels over a bandpass covering the near-ultraviolet to the near-infrared, with a resolving power R = {lambda}/FWHM {approx} 2000. Building on proven heritage, the spectrographs were upgraded for BOSS with volume-phase holographic gratings and modern CCD detectors, improving the peak throughput by nearly a factor of two, extending the bandpass to cover 360 nm < {lambda} < 1000 nm, and increasing the number of fibers from 640 to 1000 per exposure. In this paper we describe the original SDSS spectrograph design and the upgrades implemented for BOSS, and document the predicted and measured performances.

  18. Calibration of an echelle spectrograph with an astro-comb: a laser frequency comb with very high repetition rate

    NASA Astrophysics Data System (ADS)

    Phillips, David F.; Glenday, Alex; Li, Chih-Hao; Furesz, Gabor; Benedick, Andrew J.; Chang, Guoqing N.; Chen, Li-Jin; Korzennik, Sylvain; Sasselov, Dimitar; Kaertner, Franz X.; Szentgyorgyi, Andrew; Walsworth, Ronald L.

    2012-09-01

    Searches for extrasolar planets using precision radial velocity (PRV) techniques are approaching Earth-like planet sensitivity, however require an improvement of one order of magnitude to identify earth-mass planets in the habitable zone of sun-like stars. A key limitation is spectrograph calibration. An astro-comb, an octave-spanning laser frequency comb and a Fabry-Pérot cavity, producing evenly spaced frequencies with large wavelength coverage, is a promising tool for improved wavelength calibration. We demonstrate the calibration of a high-resolution astrophysical spectrograph below the 1 m/s level in the 8000-9000 Å and 4200 Å spectral bands.

  19. IMAPS - A high-resolution, echelle spectrograph to record far-ultraviolet spectra of stars from sounding rockets

    NASA Technical Reports Server (NTRS)

    Jenkins, E. B.; Joseph, C. L.; Long, D.; Zucchino, P. M.; Carruthers, G. R.

    1988-01-01

    A novel sounding rocket payload consisting of a slitless objective grating spectrograph with no transmission elements in the optical train (or detector) is described. This instrument, called the interstellar medium absorption profile spectrograph (IMAPS), is designed to provide continuous coverage over the wavelength range of 950-1150 A; it has an effective collecting area of about 4 sq cm and can record spectra of pointlike sources at a wavelength resolution of 0.004 A and with a sample interval of 0.002 A. The successful use of this instrument aboard a Black Brant rocket is described.

  20. A flux calibration device for the SuperNova Integral Field Spectrograph (SNIFS)

    NASA Astrophysics Data System (ADS)

    Lombardo, Simona; Aldering, Greg; Hoffmann, Akos; Kowalski, Marek; Kuesters, Daniel; Reif, Klaus; Rigault, Michael

    2014-07-01

    Observational cosmology employing optical surveys often require precise flux calibration. In this context we present SNIFS Calibration Apparatus (SCALA), a flux calibration system developed for the SuperNova Integral Field Spectrograph (SNIFS), operating at the University of Hawaii 2.2 m telescope. SCALA consists of a hexagonal array of 18 small parabolic mirrors distributed over the face of, and feeding parallel light to, the telescope entrance pupil. The mirrors are illuminated by integrating spheres and a wavelength-tunable (from UV to IR) light source, generating light beams with opening angles of 1°. These nearly parallel beams are flat and flux-calibrated at a subpercent level, enabling us to calibrate our "telescope + SNIFS system" at the required precision.