Science.gov

Sample records for air cerenkov telescopes

  1. Optical search for extraterrestrial intelligence with Air Cerenkov telescopes.

    PubMed

    Eichler, D; Beskin, G

    2001-01-01

    We propose using large Air Cerenkov telescopes (ACTs) to search for optical, pulsed signals from extraterrestrial intelligence. Such dishes collect tens of photons from a nanosecond-scale pulse of isotropic equivalent power of tens of solar luminosities at a distance of 100 pc. The field of view for giant ACTs can be on the order of 10 square degrees, and they will be able to monitor 10-100 stars simultaneously for nanosecond pulses of about 6th magnitude or brighter. Using the Earth's diameter as a baseline, orbital motion of the planet could be detected by timing the pulse arrivals.

  2. Status of the Whipple Observatory Cerenkov air shower imaging telescope array

    NASA Technical Reports Server (NTRS)

    Akerlof, C. W.; Cawley, M. F.; Fegan, D. J.; Fennell, S.; Freeman, S.; Frishman, D.; Harris, K.; Hillas, A. M.; Jennings, D.; Lamb, R. C.

    1992-01-01

    Recently the power of the Cerenkov imaging technique in Very High Energy gamma-ray astronomy was demonstrated by the detection of the Crab nebula at high statistical significance. In order to further develop this technique to allow the detection of weaker or more distant sources a second 10 m class reflector was constructed about 120 m from the original instrument. The addition of the second reflector will allow both a reduction in the energy threshold and an improvement in the rejection of the hadronic background. The design and construction of the second reflector, Gamma Ray Astrophysics New Imaging TElescope (GRANITE) is described.

  3. Cerenkov detectors for cosmic ray telescopes employing the Cerenkov x total energy technique of mass identification

    NASA Technical Reports Server (NTRS)

    Webber, W. R.; Kish, J. C.

    1983-01-01

    Considerable progress has been made regarding the evolution of the 'Cerenkov x total energy technique' for mass identification of cosmic ray nuclei since the introduction of telescopes employing this technique by Webber et al. (1973). Thus, significant improvements in mass resolution have been made. These improvements are mainly related to the resolution of the Cerenkov counter. The present investigation is, therefore, concerned with the properties of various types of Cerenkov detectors. In addition, a description is provided of the characteristics of a large area (approximately 0.5 sq m-ster) cosmic ray isotope telescope, which is being developed for use on balloons or spacecraft.

  4. Control Software for the VERITAS Cerenkov Telescope System

    NASA Astrophysics Data System (ADS)

    Krawczynski, H.; Olevitch, M.; Sembroski, G.; Gibbs, K.

    2003-07-01

    The VERITAS collab oration is developing a system of initially 4 and ˇ eventually 7 Cerenkov telescopes of the 12 m diameter class for high sensitivity gamma-ray astronomy in the >50 GeV energy range. In this contribution we describe the software that controls and monitors the various VERITAS subsystems. The software uses an object-oriented approach to cop e with the complexities that arise from using sub-groups of the 7 VERITAS telescopes to observe several sources at the same time. Inter-pro cess communication is based on the CORBA object Request Broker proto col and watch-dog processes monitor the sub-system performance.

  5. Cerenkov x total energy telescopes for the study of the mass composition of cosmic rays

    NASA Technical Reports Server (NTRS)

    Webber, W. R.

    1980-01-01

    The mass resolution attainable with cosmic ray telescopes employing Cerenkov counters for velocity measurement was examined. It is shown that in most cases, the limiting mass resolution is determined by the resolution of the Cerenkov counter. The resolution achieved in the UNH telescope flown on a balloon in 1977 is studied as a function of charge and energy. This telescope determines the mass using the Cerenkov x total energy technique. It is shown that the mass resolution for heavier nuclei can be accurately predicted using the response of the Cerenkov counter to sea level mu-mesons. The actual in flight resolution for heavier nuclei, including broadening effects, may be predicted using the beta = 1 Cerenkov distributions, and independently by studying the distribution function of the differences of the two banks of photomultipliers employed on each Cerenkov counter.

  6. The Gamma-ray galactic diffuse radiation and Cerenkov telescopes

    SciTech Connect

    Chardonnet, P. |; Salati, P. ||; Silk, J.; Grenier, I.; Smoot, G.

    1995-12-01

    By using the PYTHIA version of the Lund Monte Carlo program, we study the photon yield of proton-proton collisions in the energy range between 10 GeV and 1 TeV. The resulting photon spectrum turns out to scale roughly with incident energy. Then, by folding the energy spectrum of cosmic-ray protons with the distribution of HI and CO, the Galactic diffuse emission of {gamma}-rays above 100 GeV is mapped. Prospects for observing that diffuse radiation with atmospheric Cerenkov telescopes are discussed. Present instruments are able to detect the {gamma}-ray glow of the Galactic center. The latter will be mapped by the next generation of telescopes if their energy threshold is decreased. However, a detailed survey of the Galactic ridge will be a real challenge, even in the long term. The MILAGRO project seems more appropriate. Finally, we investigate the {gamma}-ray emission from weakly interacting massive particles clustering at the Galactic center. It has been speculated that those species are a major component of the halo dark matter. We show that their {gamma}-ray signal is swamped in the Galactic diffuse radiation and cannot be observed at TeV energies. {copyright} {ital 1995 The American Astronomical Society.}

  7. Cosmic ray isotope measurements with a new Cerenkov X total energy telescope

    NASA Technical Reports Server (NTRS)

    Webber, W. R.; Kish, J. C.; Schrier, D. A.

    1985-01-01

    Measurements of the isotopic composition of cosmic nuclei with Z = 7-20 are reported. These measurements were made with a new version of a Cerenkov x total E telescope. Path length and uniformity corrections are made to all counters to a RMS level 1%. Since the Cerenkov counter is crucial to mass measurements using the C x E technique - special care was taken to optimize the resolution of the 2.4 cm thick Pilot 425 Cerenkov counter. This counter exhibited a beta = 1 muon equivalent LED resolution of 24%, corresponding to a total of 90 p.e. collected at the 1st dynodes of the photomultiplier tubes.

  8. Properties of a silica aerogel Cerenkov radiator used in a cosmic ray telescope

    NASA Technical Reports Server (NTRS)

    Cantin, M.; Engelmann, J. J.; Koch, L.; Masse, P.; Lund, N.; Byrnak, B.

    1975-01-01

    A silica aerogel Cerenkov radiator with a refractive index of 1.06 has been flown in a balloon borne cosmic ray telescope. Clear separation of the elements in the iron group was achieved even at high energies. No detectable scintillation component was found. Some optical properties of the silica aerogel used in this flight are presented.

  9. The Track Imaging Cerenkov Experiment

    NASA Technical Reports Server (NTRS)

    Wissel, S. A.; Byrum, K.; Cunningham, J. D.; Drake, G.; Hays, E.; Horan, D.; Kieda, D.; Kovacs, E.; Magill, S.; Nodulman, L.; Swordy, S. P.; Wagner, R.; Wakely, S. P.

    2011-01-01

    We describe a. dedicated cosmic-ray telescope that explores a new method for detecting Cerenkov radiation from high-energy primary cosmic rays and the large particle air shower they induce upon entering the atmosphere. Using a camera comprising 16 multi-anode photomultiplier tubes for a total of 256 pixels, the Track Imaging Cerenkov Experiment (TrICE) resolves substructures in particle air showers with 0,086 deg resolution. Cerenkov radiation is imaged using a novel two-part optical system in which a Fresnel lens provides a wide-field optical trigger and a mirror system collects delayed light with four times the magnification. TrICE records well-resolved cosmic-ray air showers at rates ranging between 0.01-0.1 Hz.

  10. The Track Imaging Cerenkov Experiment

    NASA Technical Reports Server (NTRS)

    Wissel, S. A.; Byrum, K.; Cunningham, J. D.; Drake, G.; Hays, E.; Horan, D.; Kieda, D.; Kovacs, E.; Macgill, S.; Nodulman, L.; Swordy, S. P.; Wagner, R.; Wakely, S. P.

    2012-01-01

    We describe a dedicated cosmic-ray telescope that explores a new method for detecting Cerenkov radiation from high-energy primary cosmic rays and the large particle air shower they induce upon entering the atmosphere. Using a camera comprising 16 multi-anode photomultiplier tubes for a total of 256 pixels, the Track Imaging Cerenkov Experiment (TrICE) resolves substructures in particle air showers with 0.086deg resolution. Cerenkov radiation is imaged using a novel two-part optical system in which a Fresnel lens provides a wide-field optical trigger and a mirror system collects delayed light with four times the magnification. TrICE records well-resolved cosmic-ray air showers at rates ranging between 0.01-0.1 Hz.

  11. Measurement of muon intensity by Cerenkov method

    NASA Technical Reports Server (NTRS)

    Liu, Z. H.; Li, G. J.; Bai, G. Z.; Liu, J. G.; Geng, Q. X.; Ling, J.

    1985-01-01

    Optical detection is an important technique in studies and observations of air showers, muons and relevant phenomena. The muon intensity is measured in a proper energy range and to study some problems about Cerenkov radiation of cosmic rays are studied, by a muon-telescope operated with Cerenkov detector. It is found that the measured muon intensity agrees with the integral energy spectrum of cosmic ray muons.

  12. Search for Primordial Black Holes with the Whipple Atmospheric Cerenkov Telescope

    NASA Astrophysics Data System (ADS)

    Linton, Eric

    2005-04-01

    Stephen Hawking's prediction that black holes should radiate like black bodies has several important consequences, including the possibility for the detection of small (˜10^15 g) black holes created in the very early universe. The detection of such primordial black holes (PBHs) would not only validate Hawking's theory, but would provide useful insights into the history of the early universe. A search through 5.5 years of archival data from the Whipple Atmospheric Cerenkov Telescope was made for TeV gamma-ray bursts on 1 s, 3 s, and 5 s timescales. Based on a null result, an upper-limit on the evaporation rate of PBHs of 2.69 x10^6 pc-3 yr^- 1 (99% CL) was made, assuming the Standard Model of particle physics. When combined with the results of an earlier search through Whipple data, this limit was lowered to 1.33 x10^6 pc-3 yr-1, which is nearly a factor of 2 better than the previous limit at this energy range.

  13. Evolution of the Cerenkov x total-energy telescope for isotopic analysis of cosmic rays

    NASA Technical Reports Server (NTRS)

    Webber, W. R.; Simpson, G. A.; Lezniak, J. A.; Kish, J. C.

    1978-01-01

    This paper discusses the evolution of the Cerenkov x total energy technique for isotopic analysis of cosmic rays as developed by the University of New Hampshire. This technique is generally restricted to particles with Z greater than 6, and the best mass resolution is achieved over a relatively narrow energy range just above the Cerenkov threshold. State-of-the-art mass resolution is now 0.3-0.4 AMU throughout the charge range z = 8-28 and over an energy range varying from about 40 MeV/n at lower Z to about 200 MeV/n for Fe.

  14. Studies of air showers produced by primaries 10(16) eV using a combined scintillation and water-Cerenkov array

    NASA Technical Reports Server (NTRS)

    Brooke, G.; Perrett, J. C.; Watson, A. A.

    1986-01-01

    An array of 8 x 1.0 sq m plastic scintillation counters and 13 water-Cerenkov detectors (1 to 13.5 sq m) were operated at the center of the Haverah Park array to study some features of air showers produced by 10(16) eV primaries. Measurements of the scintillator lateral distribution function, the water-Cerenkov lateral distribution function, and of the distance dependence of the Cerenkov/scintillator ratio are described.

  15. Cosmic ray charge and energy spectrum measurements using a new large area Cerenkov x dE/dx telescope

    NASA Technical Reports Server (NTRS)

    Webber, W. R.; Kish, J. C.; Schrier, D. A.

    1985-01-01

    In September, 1981, a new 0.5 square meter ster cosmic ray telescope was flown to study the charge composition and energy spectrum of cosmic ray nuclei between 0.3 and 4 GeV/nuc. A high resolution Cerenkov counter, and three dE/dx measuring scintillation counters, including two position scintillators were contained in the telescope used for the charge and energy spectrum measurements. The analysis procedures did not require any large charge or energy dependent corrections, and absolute fluxes could be obtained to an accuracy approximately 5%. The spectral measurements made in 1981, at a time of extreme solar modulation, could be compared with measurements with a similar telescope made by our group in 1977, at a time of minimum modulation and can be used to derive absolute intensity values for the HEAO measurements made in 1979 to 80. Using both data sets precise energy spectra and abundance ratios can be derived over the entire energy range from 0.3 to greater than 15 GeV/nuc.

  16. Cerenkov electrooptic shutter

    DOEpatents

    Hartemann, Frederick; Bekefi, George

    1989-05-30

    A system which couples Cerenkov emission with a gated electrooptic effect to allow viewing of Cerenkov radiation in sub nanosecond time-scales is disclosed. Cerenkov radiation is generated by transmitting an electron beam through a transparent medium with a high index of refraction. The Cerenkov radiation is then gated into a sample pulse of subanosecond duration by an electrooptic crystal which has an index of refraction controlled by an electric field. the electrooptic crystal is opaque to the Cerenkov radiation until receiving a 6.0 kV voltage for about 750 picoseconds, upon which a pulsed sample of Cerenkov radiation is transmitted to a display system.

  17. Characteristics and performance of the GAW experiment for a large field of view Cerenkov {gamma} rays telescope

    SciTech Connect

    Delgado, C.

    2006-11-28

    The GAW project aims to test the feasibility of a new generation of Imaging Atmospheric Cherenkov Telescopes that join high flux sensitivity with Large Field of View capability. It consists of an array of 3 imaging Cherenkov telescopes each equipped with a Fresnel refractive lens of about 3.6 m2 geometrical area and an array of multi-anode photomultipliers at the focal surface operating in single photoelectron counting mode. Pointing along different Norouth directions, GAW would reach a survey of 360 deg. x 60 deg. region of the sky. GAW is a collaboration effort of Research Institutes in Italy, Portugal and Spain.

  18. The U.S. Air Force Academy Falcon Telescope Network

    DTIC Science & Technology

    2014-09-01

    3048 The U.S. Air Force Academy Falcon Telescope Network Francis K. Chun, Roger D. Tippets, Michael E. Dearborn Department of Physics, U.S. Air...The Falcon Telescope Network (FTN) is a global network of small aperture telescopes developed by the Center for Space Situational Awareness...provides the equipment (e.g. telescope , mount, camera, filter wheel, dome, weather station, computers and storage devices) while the educational partners

  19. Construction of a cosmic ray air shower telescope

    NASA Technical Reports Server (NTRS)

    Ng, L. K.; Chan, S. K.

    1985-01-01

    The telescope under construction is mainly for the purpose of locating the arrival directions of energetic particles and quanta which generate air showers of sizes 10 to the 5th power to 10 to the 6th power. Both fast timing method and visual track method are incorporated in determining the arrival directions. The telescope is composed of four stations using scintillators and neon flash tubes as detectors. The system directional resolution is better than 1.5 deg.

  20. Cerenkov fiber sampling calorimeters

    SciTech Connect

    Arrington, K.; Kefford, D.; Kennedy, J.; Pisani, R.; Sanzeni, C.; Segall, K.; Wall, D.; Winn, D.R. ); Carey, R.; Dye, S.; Miller, J.; Sulak, L.; Worstell, W. ); Efremenko, Y.; Kamyshkov, Y.; Savin, A.; Shmakov, K.; Tarkovsky, E. )

    1994-08-01

    Clear optical fibers were used as a Cerenkov sampling media in Pb (electromagnetic) and Cu (hadron) absorbers in spaghetti calorimeters, for high rate and high radiation dose experiments, such as the forward region of high energy colliders. The fiber axes were aligned close to the direction of the incident particles (1[degree]--7[degree]). The 7 [lambda] deep hadron tower contained 2.8% by volume 1.5 mm diameter core clear plastic fibers. The 27 radiation length deep electromagnetic towers had packing fractions of 6.8% and 7.2% of 1 mm diameter core quartz fibers as the active Cerenkov sampling medium. The energy resolution on electrons and pions, energy response, pulse shapes and angular studies are presented.

  1. Detection of tau neutrinos by imaging air Cherenkov telescopes

    NASA Astrophysics Data System (ADS)

    Góra, D.; Bernardini, E.

    2016-09-01

    This paper investigates the potential to detect tau neutrinos in the energy range of 1-1000 PeV searching for very inclined showers with imaging Cherenkov telescopes. A neutrino induced tau lepton escaping from the Earth may decay and initiate an air shower which can be detected by a fluorescence or Cherenkov telescope. We present here a study of the detection potential of Earth-skimming neutrinos taking into account neutrino interactions in the Earth crust, local matter distributions at various detector sites, the development of tau-induced showers in air and the detection of Cherenkov photons with IACTs. We analyzed simulated shower images on the camera focal plane and implemented generic reconstruction chains based on Hillas parameters. We find that present IACTs can distinguish air showers induced by tau neutrinos from the background of hadronic showers in the PeV-EeV energy range. We present the neutrino trigger efficiency obtained for a few configurations being considered for the next-generation Cherenkov telescopes, i.e. the Cherenkov Telescope Array. Finally, for a few representative neutrino spectra expected from astrophysical sources, we compare the expected event rates at running IACTs to what is expected for the dedicated IceCube neutrino telescope.

  2. Silicone Cerenkov-Radiator Material

    NASA Technical Reports Server (NTRS)

    Balasubrahmanyan, V.; Ormes, J. F.; Streitmatter, R. E.

    1984-01-01

    Dyes enhance visible output. Three fluorescent dyes combine to increase output of silicone material that normally has low yield of visible Cerenkov radiation by converting large amount of available ultraviolet photons into visible light.

  3. New method of analysis for TeV gamma-ray data collected by the TACTIC telescope

    NASA Astrophysics Data System (ADS)

    Krishen, Chand

    2016-10-01

    We describe a new fractal and wavelet based framework for analysing atmospheric Cerenkov images of extensive air showers. The methodology developed using simulated data has been tested with the data collected from Mrk421 and Crab nebula directions during 10 October 2009-16 May 2010 by the TACTIC telescope. The telescope detected flaring activity in TeV gamma-rays from Mrk421 during 15th-17th February 2010. Hillas parameter analysis of Cerenkov images showed presence of TeV γ-ray signal with statistical significance of 12.5 σ beyond 1TeV energy for the 265 hours data set. Based on a Monte-Carlo simulated database of Cerenkov images recorded by the TACTIC telescope, the wavelet dimension B6 can be exploited as a useful parameter to segregate gamma-ray initiated events from hadron initiated events with better efficiency. We derive a preliminary value of the relevant significance for gamma initiated events using wavelet parameter B6 for the 265 hours long observation spell of Mrk421 including the flaring episode during 15th-17th February 2010 and 66 hours data of observations on Crab nebula. Wavelet analysis approach has also been tested on Crab OFF- source data of 27 hours. Application of wavelet parameter B6 on the recorded Cerenkov images of the TACTIC telescope reveals better results in terms of segregation efficiency and enhancement of the determined value of statistical significance as compared to the Hillas parameters approach.

  4. The U.S. Air Force Academy Falcon Telescope Network

    DTIC Science & Technology

    2014-09-05

    The Falcon Telescope Network (FTN) is a global network of small aperture telescopes developed by the Center for Space Situational Awareness Research...equipment (e.g. telescope , mount, camera, filter wheel, dome, weather stations, computers and storage devices) while the educational partners provide...After an observational request is completed, the FTN user will receive notification of collection and a link to the data. The Falcon Telescope Network

  5. Study of the shower maximum depth by the method of detection of the EAS Cerenkov light pulse shape

    NASA Technical Reports Server (NTRS)

    Aliev, N.; Alimov, T.; Kakhkharov, M.; Khakimov, N.; Makhmudov, B. M.; Rakhimova, N.; Tashpulatov, R.; Khristiansen, G. B.; Prosin, V. V.; Zhukov, V. Y.

    1985-01-01

    The results of processing the data on the shape of the EAS Cerenkov light pulses recorded by the extensive air showers (EAS) array are presented. The pulse FWHM is used to find the mean depth of EAS maximum.

  6. Time correlation measurements from extensive air showers detected by the EEE telescopes

    NASA Astrophysics Data System (ADS)

    Abbrescia, M.; Agocs, A.; Aiola, S.; Antolini, R.; Avanzini, C.; Baldini Ferroli, R.; Bencivenni, G.; Bossini, E.; Bressan, E.; Chiavassa, A.; Cicalò, C.; Cifarelli, L.; Coccia, E.; De Gruttola, D.; De Pasquale, S.; Di Giovanni, A.; D'Incecco, M.; Dreucci, M.; Fabbri, F. L.; Frolov, V.; Garbini, M.; Gemme, G.; Gnesi, I.; Gustavino, C.; Hatzifotiadou, D.; La Rocca, P.; Li, S.; Librizzi, F.; Maggiora, A.; Massai, M.; Miozzi, S.; Panareo, M.; Paoletti, R.; Perasso, L.; Pilo, F.; Piragino, G.; Regano, A.; Riggi, F.; Righini, G. C.; Sartorelli, G.; Scapparone, E.; Scribano, A.; Selvi, M.; Serci, S.; Siddi, E.; Spandre, G.; Squarcia, S.; Taiuti, M.; Tosello, F.; Votano, L.; Williams, M. C. S.; Yanez, G.; Zichichi, A.; Zouyevski, R.

    2013-12-01

    Time correlated events due to cosmic muons from extensive air showers have been detected by means of telescope pairs of the EEE (Extreme Energy Events) Project array. The coincidence rate, properly normalized for detector acceptance, efficiency and altitude location, has been extracted as a function of the relative distance between the telescopes. The results have been also compared with additional measurements carried out by small scintillator detectors at various distances.

  7. A threshold gas Cerenkov detector for the spin asymmetries of the nucleon experiment

    DOE PAGES

    Armstrong, Whitney R.; Choi, Seonho; Kaczanowicz, Ed; ...

    2015-09-26

    In this study, we report on the design, construction, commissioning, and performance of a threshold gas Cerenkov counter in an open configuration, which operates in a high luminosity environment and produces a high photo-electron yield. Part of a unique open geometry detector package known as the Big Electron Telescope Array, this Cerenkov counter served to identify scattered electrons and reject produced pions in an inclusive scattering experiment known as the Spin Asymmetries of the Nucleon Experiment E07-003 at the Thomas Jefferson National Accelerator Facility (TJNAF) also known as Jefferson Lab. The experiment consisted of a measurement of double spin asymmetriesmore » A|| and A⊥ of a polarized electron beam impinging on a polarized ammonia target. The Cerenkov counter's performance is characterised by a yield of about 20 photoelectrons per electron or positron track. Thanks to this large number of photoelectrons per track, the Cerenkov counter had enough resolution to identify electron-positron pairs from the conversion of photons resulting mainly from π0 decays.« less

  8. A threshold gas Cerenkov detector for the spin asymmetries of the nucleon experiment

    SciTech Connect

    Armstrong, Whitney R.; Choi, Seonho; Kaczanowicz, Ed; Lukhanin, Alexander; Meziani, Zein -Eddine; Sawatzky, Brad D.

    2015-09-26

    In this study, we report on the design, construction, commissioning, and performance of a threshold gas Cerenkov counter in an open configuration, which operates in a high luminosity environment and produces a high photo-electron yield. Part of a unique open geometry detector package known as the Big Electron Telescope Array, this Cerenkov counter served to identify scattered electrons and reject produced pions in an inclusive scattering experiment known as the Spin Asymmetries of the Nucleon Experiment E07-003 at the Thomas Jefferson National Accelerator Facility (TJNAF) also known as Jefferson Lab. The experiment consisted of a measurement of double spin asymmetries A|| and A of a polarized electron beam impinging on a polarized ammonia target. The Cerenkov counter's performance is characterised by a yield of about 20 photoelectrons per electron or positron track. Thanks to this large number of photoelectrons per track, the Cerenkov counter had enough resolution to identify electron-positron pairs from the conversion of photons resulting mainly from π0 decays.

  9. STS 31 PAYLOAD HUBBLE SPACE TELESCOPE ENCLOSED IN AN AIR-TIGHT PLASTIC BAG FOR PROTECTION IN VERTICA

    NASA Technical Reports Server (NTRS)

    1989-01-01

    Preparations are made to enclose the Hubble Space Telescope [HST] inside an air-tight plastic bag in the VPF. Processing of the 94- inch primary mirror telescope for launch on the Discovery in March 1990, involves working within strict controls to prevent contamination.

  10. A dynamic thermal model for design and control of an 800-element open-air radio telescope

    NASA Astrophysics Data System (ADS)

    Bremer, Michael; Greve, Albert

    2011-09-01

    In earlier work we have described the thermal modelling for design and control of a fully insulated, and sometimes ventilated, high precision radio telescope. For such an insulated telescope the modelling of the time-variable dynamic influence of the thermal environment (air, sky and ground radiation, insolation) is relatively simple. The modelling becomes however quite complex for an open-air radio telescope where each individual member of the reflector backup structure (BUS) and the support structure (fork or yoke) is exposed under a different and time-dependent aspect angle to the thermal environment, which applies in particular to solar radiation. We present a time-dependent 800-element thermal model of an open-air telescope. Using the IRAM 30-m radio telescope as the basic mechanical structure, we explain how the temperature induced, real-time pointing and reflector surface deformations can be derived when using as input the day of the year, the thermal environment, and the geographic position of the telescope and its changing pointing direction. Thermal modelling and results similar to those reported here can be used for radio telescope design and real-time control of pointing and surface adjustment of a telescope with active panels.

  11. EAS Cerenkov measurements of the composition of the cosmic ray flux around 10 to the 16th power eV

    NASA Technical Reports Server (NTRS)

    Dawson, B. R.; Prescott, J. R.; Clay, R. W.

    1985-01-01

    Information can be obtained about the nature of a primary cosmic ray by looking at the way in which an extensive air shower (EAS) develops in the atmosphere. Heavy nuclei give rise to showers that develop high in the atmosphere and the depth of maximum development is subjected to much smaller fluctuations than is the case for showers originating from protons. This development is followed by optical methods based on the observations of Cerenkov light or fluorescence light. The Cerenkov observations have two complementary techniques: measurement of the time profile of the Cerenkov pulse with resolution of a few nanoseconds and measurement of the lateral distribution of the Cerenkov light. In each case the measured quantities must be related to some characteristic development parameters.

  12. Diffraction Effects in Cerenkov Radiation.

    DTIC Science & Technology

    1983-06-01

    the gas is very close to one. Consequently the dependance of ec on the electron velocity is very slight since B must also be close to one in order to...0 5 10 l em . ~Figure 4. Dependance of the first maximum in D3() as a ~function of gas (air) cell length. 22 .% 10 :1, ID a it 0 5 10 HARMONIC FIGURE

  13. The background from single electromagnetic subcascades for a stereo system of air Cherenkov telescopes

    NASA Astrophysics Data System (ADS)

    Sobczyńska, Dorota

    2009-12-01

    The MAGIC experiment, a very large imaging air Cherenkov telescope (IACT) with sensitivity to low-energy (E < 100 GeV) VHE gamma rays, has been operated since 2004. It has been found that the γ/hadron separation in IACTs becomes much more difficult below 100 GeV (Albert J et al 2008 Astrophys. J. 674 1037). A system of two large telescopes may eventually be triggered by hadronic events containing Cherenkov light from only one electromagnetic subcascade or two γ subcascades, which are products of the single π0 decay. This is a possible reason for the deterioration of the experiment's sensitivity below 100 GeV. In this paper, a system of two MAGIC telescopes working in a stereoscopic mode is studied using Monte Carlo simulations. The detected images have similar shapes to that of primary γ-rays, and they have small sizes (mainly below 400 photoelectrons (pe)) which correspond to an energy of primary γ-rays below 100 GeV. The background from single or two electromagnetic subcascades is concentrated at energies below 200 GeV. Finally, the number of background events is compared to the number of VHE γ-ray excess events from the Crab Nebula. The investigated background survives simple cuts for sizes below 250 pe, and thus the experiment's sensitivity deteriorates at lower energies.

  14. Anomalous dispersion enhanced Cerenkov phase-matching

    SciTech Connect

    Kowalczyk, T.C.; Singer, K.D.; Cahill, P.A.

    1993-11-01

    The authors report on a scheme for phase-matching second harmonic generation in polymer waveguides based on the use of anomalous dispersion to optimize Cerenkov phase matching. They have used the theoretical results of Hashizume et al. and Onda and Ito to design an optimum structure for phase-matched conversion. They have found that the use of anomalous dispersion in the design results in a 100-fold enhancement in the calculated conversion efficiency. This technique also overcomes the limitation of anomalous dispersion phase-matching which results from absorption at the second harmonic. Experiments are in progress to demonstrate these results.

  15. Development of a PET/Cerenkov-light hybrid imaging system

    SciTech Connect

    Yamamoto, Seiichi Hamamura, Fuka; Kato, Katsuhiko; Ogata, Yoshimune; Watabe, Tadashi; Ikeda, Hayato; Kanai, Yasukazu; Hatazawa, Jun; Watabe, Hiroshi

    2014-09-15

    Purpose: Cerenkov-light imaging is a new molecular imaging technology that detects visible photons from high-speed electrons using a high sensitivity optical camera. However, the merit of Cerenkov-light imaging remains unclear. If a PET/Cerenkov-light hybrid imaging system were developed, the merit of Cerenkov-light imaging would be clarified by directly comparing these two imaging modalities. Methods: The authors developed and tested a PET/Cerenkov-light hybrid imaging system that consists of a dual-head PET system, a reflection mirror located above the subject, and a high sensitivity charge coupled device (CCD) camera. The authors installed these systems inside a black box for imaging the Cerenkov-light. The dual-head PET system employed a 1.2 × 1.2 × 10 mm{sup 3} GSO arranged in a 33 × 33 matrix that was optically coupled to a position sensitive photomultiplier tube to form a GSO block detector. The authors arranged two GSO block detectors 10 cm apart and positioned the subject between them. The Cerenkov-light above the subject is reflected by the mirror and changes its direction to the side of the PET system and is imaged by the high sensitivity CCD camera. Results: The dual-head PET system had a spatial resolution of ∼1.2 mm FWHM and sensitivity of ∼0.31% at the center of the FOV. The Cerenkov-light imaging system's spatial resolution was ∼275μm for a {sup 22}Na point source. Using the combined PET/Cerenkov-light hybrid imaging system, the authors successfully obtained fused images from simultaneously acquired images. The image distributions are sometimes different due to the light transmission and absorption in the body of the subject in the Cerenkov-light images. In simultaneous imaging of rat, the authors found that {sup 18}F-FDG accumulation was observed mainly in the Harderian gland on the PET image, while the distribution of Cerenkov-light was observed in the eyes. Conclusions: The authors conclude that their developed PET/Cerenkov-light hybrid

  16. Daniel K. Inouye Solar Telescope: computational fluid dynamic analyses and evaluation of the air knife model

    NASA Astrophysics Data System (ADS)

    McQuillen, Isaac; Phelps, LeEllen; Warner, Mark; Hubbard, Robert

    2016-08-01

    Implementation of an air curtain at the thermal boundary between conditioned and ambient spaces allows for observation over wavelength ranges not practical when using optical glass as a window. The air knife model of the Daniel K. Inouye Solar Telescope (DKIST) project, a 4-meter solar observatory that will be built on Haleakalā, Hawai'i, deploys such an air curtain while also supplying ventilation through the ceiling of the coudé laboratory. The findings of computational fluid dynamics (CFD) analysis and subsequent changes to the air knife model are presented. Major design constraints include adherence to the Interface Control Document (ICD), separation of ambient and conditioned air, unidirectional outflow into the coudé laboratory, integration of a deployable glass window, and maintenance and accessibility requirements. Optimized design of the air knife successfully holds full 12 Pa backpressure under temperature gradients of up to 20°C while maintaining unidirectional outflow. This is a significant improvement upon the .25 Pa pressure differential that the initial configuration, tested by Linden and Phelps, indicated the curtain could hold. CFD post- processing, developed by Vogiatzis, is validated against interferometry results of initial air knife seeing evaluation, performed by Hubbard and Schoening. This is done by developing a CFD simulation of the initial experiment and using Vogiatzis' method to calculate error introduced along the optical path. Seeing error, for both temperature differentials tested in the initial experiment, match well with seeing results obtained from the CFD analysis and thus validate the post-processing model. Application of this model to the realizable air knife assembly yields seeing errors that are well within the error budget under which the air knife interface falls, even with a temperature differential of 20°C between laboratory and ambient spaces. With ambient temperature set to 0°C and conditioned temperature set to 20

  17. Fundamental research on a cerenkov radiation sensor based on optical glass for detecting beta-rays

    NASA Astrophysics Data System (ADS)

    Kim, Jae Seok; Jang, Kyoung Won; Shin, Sang Hun; Jeon, Dayeong; Hong, Seunghan; Sim, Hyeok In; Kim, Seon Geun; Yoo, Wook Jae; Lee, Bongsoo; Moon, Joo Hyun; Park, Byung Gi

    2015-01-01

    In this study, a Cerenkov radiation sensor for detecting low-energy beta-particles was fabricated using various Cerenkov radiators such as an aerogel and CaF2-, SiO2-, and Al2O3-based optical glasses. Because the Cerenkov threshold energy (CTE) is determined by the refractive index of the Cerenkov radiator, the intensity of Cerenkov radiation varies according to the refractive indices of the Cerenkov radiators. Therefore, we measured the intensities of Cerenkov radiation induced by beta-particles generated from a radioactive isotope as a function of the refractive indices of the Cerenkov radiators. Also, the electron fluxes were calculated for various Cerenkov radiators by using a Monte Carlo N-Particle extended transport code (MCNPX) to determine the relationship between the intensities of the Cerenkov radiation and the electron fluxes.

  18. University of Iowa Cerenkov light test

    SciTech Connect

    Not Available

    2005-09-01

    This Memorandum of Understanding requests beam time at Fermilab during the Winter 2005-2006 Meson Test Run to measure the signal size from various configurations of Cerenkov light generators and phototubes. The University of Iowa has pioneered in application of Cerenkov radiation for high-energy detectors. One of the results of this effort is the huge forward calorimeter for CMS (at the LHC) with a half million quartz fibers in iron. The laboratory plans to use this expertise to develop a variety of detectors making use of Cerenkov light and phototubes as the active elements in calorimeters for high-energy particles. There are three immediate applications related to forward angle calorimeters in CMS; ZDC, CASTOR, and the HE upgrade. The University of Iowa will make the detailed design for the Zero Degree Calorimeter. The proposed design uses tungsten plates interleaved with sheets of quartz fibers. In the EM part the plates are perpendicular to the beam, in the rear hadronic part they are at an angle of 45{sup o}. Because of the limited cross sectional area of the plates, there will be considerable leakage of shower particles out of the four sides. We plan to measure this leakage and compare the results with simulations. The leakage will be measured by placing a polished aluminum tank, 4 in wide, 20 in long and 8 in deep on top of absorber material made of blocks of tantalum and copper. The fluid in the tank, that generates the Ccrcnkov light, could be water; but ethylene glycol (antifreeze, but without the added color) would be better. Being non-polar, it is not corrosive like water, and it has a higher index of refraction, 1.42 vs. 1.33. The larger index of refraction would result in more Cerenkov light and better coupling to the PMT. The University of Iowa has been asked to design the light guides for CASTOR that take the light from the quartz plates, in which the light is produced, and carry it to the PMTs. These plates, interleaved with tungsten plates, are

  19. Cosmogenic neutrinos and signals of TeV gravity in air showers and neutrino telescopes.

    PubMed

    Illana, J I; Masip, M; Meloni, D

    2004-10-08

    The existence of extra dimensions allows the possibility that the fundamental scale of gravity is at the TeV. If that is the case, gravity could dominate the interactions of ultrahigh energy cosmic rays. In particular, the production of microscopic black holes by cosmogenic neutrinos has been estimated in a number of papers. We consider here gravity-mediated interactions at larger distances, where they can be calculated in the eikonal approximation. We show that for the expected flux of cosmogenic neutrinos these elastic processes give a stronger signal than black hole production in neutrino telescopes. Taking the bounds on the higher-dimensional Planck mass M(D) (D=4 + n) from current air shower experiments, for n=2(6) elastic collisions could produce up to 118 (34) events per year at IceCube. On the other hand, the absence of any signal would imply a bound of M(D) > or approximately 5 TeV.

  20. Characterization of fiber optic Cerenkov radiation sensor for detecting neutrons

    NASA Astrophysics Data System (ADS)

    Jang, K. W.; Yagi, T.; Pyeon, C. H.; Shin, S. H.; Yoo, W. J.; Misawa, T.; Lee, B.

    2013-09-01

    Cerenkov radiation can be observed easily as a shimmer of blue light from the water in boiling- and pressurized-water reactors, or spent fuel storage pools. In this research, we fabricated the fiber-optic Cerenkov radiation sensor using a Gdfoil, rutile crystal and optical fiber for detecting neutrons. Also, the reference sensor for measuring background gammarays was fabricated with the rutile crystal and optical fiber. The neutron fluxes could be obtained by measuring the signal difference between two sensors. To characterize the fiber-optic Cerenkov radiation sensor, we measured neutron fluxes using a Cf-252 neutron source according to depths of polyethylene. As the results, the counts of fiber-optic Cerenkov radiation sensor were higher than those of reference sensor due to additional interactions between Gd-foil and neutrons. Also, the counts of Cerenkov radiation decreased with increasing polyethylene thickness. It is anticipated that the novel and simple fiber-optic Cerenkov radiation sensor using the Cerenkov effect can be widely used to detect the neutrons in hazardous nuclear facilities.

  1. Novel biomedical applications of Cerenkov radiation and radioluminescence imaging.

    PubMed

    Spinelli, Antonello E; Boschi, Federico

    2015-03-01

    The main goals of this review is to provide an up-to-date account of the different uses of Cerenkov radiation (CR) and radioluminescence imaging for pre-clinical small animal imaging. We will focus on new emerging applications such as the use of Cerenkov imaging for monitoring radionuclide and external radiotherapy in humans. Another novel application that will be described is the monitoring of radiochemical synthesis using microfluidic chips. Several pre-clinical aspects of CR will be discussed such as the development of 3D reconstruction methods for Cerenkov images and the use of CR as excitation source for nanoparticles or for endoscopic imaging. We will also include a discussion on radioluminescence imaging that is a more general method than Cerenkov imaging for the detection using optical methods of alpha and gamma emitters.

  2. Development of a Cerenkov radiation sensor to detect low-energy beta-particles.

    PubMed

    Yoo, Wook Jae; Han, Ki-Tek; Shin, Sang Hun; Seo, Jeong Ki; Jeon, Dayeong; Lee, Bongsoo

    2013-11-01

    We fabricated a novel fiber-optic Cerenkov radiation sensor using a Cerenkov radiator for measuring beta-particles. Instead of employing a scintillator, transparent liquids having various refractive indices were used as a Cerenkov radiator to serve as a sensing material. The experimental results showed that the amount of Cerenkov radiation due to the interaction with beta-particles increased as the refractive index of the Cerenkov radiator was increased as a results of a decrease of the Cerenkov threshold energy for electrons.

  3. Optimization of microfluidic PET tracer synthesis with Cerenkov imaging†

    PubMed Central

    Dooraghi, Alex A.; Keng, Pei Y.; Chen, Supin; Javed, Muhammad R.; Kim, Chang-Jin “CJ”; Chatziioannou, Arion F.; van Dam, R. Michael

    2013-01-01

    Microfluidic technologies provide an attractive platform for the synthesis of radiolabeled compounds. Visualization of radioisotopes on chip is critical for synthesis optimization and technological development. With Cerenkov imaging, beta particle emitting isotopes can be localized with a sensitive CCD camera. In order for Cerenkov imaging to also serve as a quantitative tool, it is necessary to understand how material properties relevant to Cerenkov emission, namely, index of refraction and beta particle stopping power, affect Cerenkov light output. In this report, we investigate the fundamental physical characteristics of Cerenkov photon yield at different stages of [18F]FDG synthesis on the electrowetting on dielectric (EWOD) microfluidic platform. We also demonstrate how Cerenkov imaging has enabled synthesis optimization. Geant4, a Monte Carlo program applied extensively in high energy physics, is used to simulate Cerenkov photon yield from 18F beta particles traversing materials of interest during [18F]FDG synthesis on chip. Our simulations show that the majority (approximately two-thirds) of the 18F beta particle energy available to produce Cerenkov photons is deposited on the glass plates of the EWOD chip. This result suggests the possibility of using a single calibration factor to convert Cerenkov signal to radioactivity, independent of droplet composition. We validate our simulations with a controlled measurement examining varying ratios of [18O]H2O, dimethyl sulfoxide (DMSO), and acetonitrile (MeCN), and find a consistent calibration independent of solvent composition. However, the calibration factor may underestimate the radioactivity in actual synthesis due to discoloration of the droplet during certain steps of probe synthesis. In addition to the attractive quantitative potential of Cerenkov imaging, this imaging strategy provides indispensable qualitative data to guide synthesis optimization. We are able to use this imaging technique to optimize the

  4. Nonlinear analysis of the Cerenkov maser

    SciTech Connect

    Freund, H.P.; Ganguly, A.K. )

    1990-10-01

    The nonlinear evolution of the Cerenkov maser amplifier is investigated numerically for a configuration that consists of an energetic electron beam propagating through a dielectric-lined cylindrical waveguide. An axial guide magnetic field is included in the formulation in order to improve beam confinement. A set of coupled nonlinear differential equations is derived in three dimensions that governs the evolution of both the electromagnetic field and the trajectories of an ensemble of electrons. The system is assumed to be azimuthally symmetric, and the electromagnetic field is represented as a superposition of the TM{sub 0{ital n}} modes of the vacuum waveguide. The initial conditions are chosen to model the simultaneous injection of either a solid or annular electron beam, and an electromagnetic wave of arbitrary input power. Thermal effects are treated under the assumption that the beam is {ital initially} monoenergetic but exhibits a pitch angle spread; however, the subsequent evolution of the beam is treated in a self-consistent manner. This class of distribution is appropriate to the treatment of diode-produced beams and describes a beam with an initial axial energy spread. This is the crucial determinant in the efficiency, since saturation occurs by means of an axial bunching mechanism that results in the phase trapping of the beam. The specific parameters used in the numerical analysis correspond to experiments conducted at Dartmouth College (J. Appl. Phys. {bold 58}, 627 (1985)), and good agreement is found between theory and experiment.

  5. The physics of Cerenkov light production during proton therapy.

    PubMed

    Helo, Y; Kacperek, A; Rosenberg, I; Royle, G; Gibson, A P

    2014-12-07

    There is increasing interest in using Cerenkov emissions for quality assurance and in vivo dosimetry in photon and electron therapy. Here, we investigate the production of Cerenkov light during proton therapy and its potential applications in proton therapy. A primary proton beam does not have sufficient energy to generate Cerenkov emissions directly, but we have demonstrated two mechanisms by which such emissions may occur indirectly: (1) a fast component from fast electrons liberated by prompt gamma (99.13%) and neutron (0.87%) emission; and (2) a slow component from the decay of radioactive positron emitters. The fast component is linear with dose and doserate but carries little spatial information; the slow component is non-linear but may be localised. The properties of the two types of emission are explored using Monte Carlo modelling in GEANT4 with some experimental verification. We propose that Cerenkov emissions could contribute to the visual sensation reported by some patients undergoing proton therapy of the eye and we discuss the feasibility of some potential applications of Cerenkov imaging in proton therapy.

  6. Proton radiography based on near-threshold Cerenkov radiation

    DOEpatents

    van Bibber, Karl A.; Dietrich, Frank S.

    2003-01-01

    A Cerenkov imaging system for charged particle radiography that determines the energy loss of the charged particle beam passing through an object. This energy loss information provides additional detail on target densities when used with traditional radiographic techniques like photon or x-ray radiography. In this invention a probe beam of 800 MeV to 50 GeV/c charged particles is passed through an object to be imaged, an imaging magnetic spectrometer, to a silicon aerogel Cerenkov radiator where the charged particles emitted Cerenkov light proportional to their velocity. At the same beam focal plane, a particle scintillator produces a light output proportional to the incident beam flux. Optical imaging systems relay the Cerenkov and scintillator information to CCD's or other measurement equipment. A ratio between the Cerenkov and scintillator is formed, which is directly proportional to the line density of the object for each pixel measured. By rotating the object, tomographic radiography may be performed. By applying pulses of beam, discrete time-step movies of dynamic objects may be made.

  7. The effect of the atmospheric condition on the extensive air shower analysis at the Telescope Array experiment

    SciTech Connect

    Kobayashi, Y.; Tsunesada, Y.; Tokuno, H.; Kakimoto, F.; Tomida, T.

    2011-09-22

    The accuracies in determination of air shower parameters such as longitudinal profiles or primary energies with the fluorescence detection technique are strongly dependent on atmospheric conditions of the molecular and aerosol components. Moreover, air fluorescence photon yield depends on the atmospheric density, and the transparency of the air for fluorescence photons depends on the atmospheric conditions from EAS to FDs. In this paper, we describe the atmospheric monitoring system in the Telescope Array (TA experiment), and the impact of the atmospheric conditions in air shower reconstructions. The systematic uncertainties of the determination of the primary cosmic ray energies and of the measurement of depth of maximum development (X{sub max}) of EASs due to atmospheric variance are evaluated by Monte Carlo simulation.

  8. Cerenkov counters for high energy nuclei: Some new developments

    NASA Technical Reports Server (NTRS)

    Swordy, S. P.; Muller, D.

    1985-01-01

    A method to determine with gas Cerenkov counters the Lorentz factor, gamma = E/mc, of cosmic ray nuclei with high accuracy over the range gamma approx. 20 to 100 is discussed. The measurement of the Cerenkov emission angle theta, by use of a suitable imaging system is considered. Imaging counters, the ring imaging Cerenkov counters (RICH), were developed for use on accelerators. The image of off-axis particles to determine the amount of image distortion as a function of the direction of the incoming nucleus is examined and an acceptance solid angle, relative to the optical axis, within which the nucleus produces an image with an acceptable level of distortion is defined. The properties of the image, which becomes elliptical, for off-axis particles are analyzed.

  9. The SLD Cerenkov Ring Imaging Detector: Progress report

    SciTech Connect

    Ashford, V.; Bienz, T.; Bird, F.; Crawford, G.; Gaillard, M.; Hallewell, G.; Leith, D.; McShurley, D.; Nuttall, A.; Oxoby, G.

    1986-10-01

    We describe test beam results from a prototype Cerenkov Ring Imaging Detector (CRID) for the SLD experiment at the SLAC Linear Collider (SLC). The system includes both liquid and gas radiators, a long drift box containing gaseous TMAE and a proportional wire chamber with charge division readout. Measurements of the multiplicity and detection resolution of Cerenkov photons, from both radiators are presented. Various design aspects of a new engineering prototype, currently under construction, are discussed and recent R and D results relevant to this effort are reported.

  10. The Telescope Array RADAR (TARA) Project and the Search for the Radar Signature of Cosmic Ray Induced Extensive Air Showers

    NASA Astrophysics Data System (ADS)

    Prohira, Steven; TARA Collaboration; Telescope Array Collaboration

    2016-03-01

    The TARA (Telescope Array Radar) cosmic ray detector has been in operation since May 2013. It is the most ambitious effort to date to test an idea that originated in the 1940's: that ionization produced by cosmic ray extensive air showers should reflect electromagnetic radiation. The observation of this effect would open the possibility that remote-sensing radar technology could be used to detect and reconstruct extensive air showers, thus increasing the aperture available for the study of the highest-energy cosmic rays. TARA employs a bi-static radar configuration, consisting of a 25 kW, 5 MW ERP transmitter at 54.1 MHz broadcasting across the Telescope Array surface detector. 40 km distant, a set of log-periodic receiver antennas are read out by two independent data acquisition systems employing different techniques to select signals of the form expected for radar targets moving at close to the speed of light. In this talk, we describe the TARA detector and present the first quantitative limits on the radar cross-section of extensive air showers.

  11. Method for monitoring irradiated fuel using Cerenkov radiation

    DOEpatents

    Dowdy, E.J.; Nicholson, N.; Caldwell, J.T.

    1980-05-21

    A method is provided for monitoring irradiated nuclear fuel inventories located in a water-filled storage pond wherein the intensity of the Cerenkov radiation emitted from the water in the vicinity of the nuclear fuel is measured. This intensity is then compared with the expected intensity for nuclear fuel having a corresponding degree of irradiation exposure and time period after removal from a reactor core. Where the nuclear fuel inventory is located in an assembly having fuel pins or rods with intervening voids, the Cerenkov light intensity measurement is taken at selected bright sports corresponding to the water-filled interstices of the assembly in the water storage, the water-filled interstices acting as Cerenkov light channels so as to reduce cross-talk. On-line digital analysis of an analog video signal is possible, or video tapes may be used for later measurement using a video editor and an electrometer. Direct measurement of the Cerenkov radiation intensity also is possible using spot photometers pointed at the assembly.

  12. Projection imaging of photon beams by the Cerenkov effect

    SciTech Connect

    Glaser, Adam K.; Davis, Scott C.; McClatchy, David M.; Zhang, Rongxiao; Pogue, Brian W.; Gladstone, David J.

    2013-01-15

    Purpose: A novel technique for beam profiling of megavoltage photon beams was investigated for the first time by capturing images of the induced Cerenkov emission in water, as a potential surrogate for the imparted dose in irradiated media. Methods: A high-sensitivity, intensified CCD camera (ICCD) was configured to acquire 2D projection images of Cerenkov emission from a 4 Multiplication-Sign 4 cm{sup 2} 6 MV linear accelerator (LINAC) x-ray photon beam operating at a dose rate of 400 MU/min incident on a water tank with transparent walls. The ICCD acquisition was gated to the LINAC sync pulse to reduce background light artifacts, and the measurement quality was investigated by evaluating the signal to noise ratio and measurement repeatability as a function of delivered dose. Monte Carlo simulations were used to derive a calibration factor for differences between the optical images and deposited dose arising from the anisotropic angular dependence of Cerenkov emission. Finally, Cerenkov-based beam profiles were compared to a percent depth dose (PDD) and lateral dose profile at a depth of d{sub max} from a reference dose distribution generated from the clinical Varian ECLIPSE treatment planning system (TPS). Results: The signal to noise ratio was found to be 20 at a delivered dose of 66.6 cGy, and proportional to the square root of the delivered dose as expected from Poisson photon counting statistics. A 2.1% mean standard deviation and 5.6% maximum variation in successive measurements were observed, and the Monte Carlo derived calibration factor resulted in Cerenkov emission images which were directly correlated to deposited dose, with some spatial issues. The dose difference between the TPS and PDD predicted by Cerenkov measurements was within 20% in the buildup region with a distance to agreement (DTA) of 1.5-2 mm and {+-}3% at depths beyond d{sub max}. In the lateral profile, the dose difference at the beam penumbra was within {+-}13% with a DTA of 0-2 mm

  13. Brief history of ground-based very high energy gamma-ray astrophysics with atmospheric air Cherenkov telescopes

    NASA Astrophysics Data System (ADS)

    Mirzoyan, Razmik

    2014-01-01

    The discovery of the Crab Nebula as the first source of TeV gamma rays in 1989, using the technique of ground-based imaging air Cherenkov telescope, has marked the birthday of observational gamma astronomy in very high energy range. The team led by Trevor Weekes, after twenty years of trial and error, success and misfortune, step-by-step improvements in both the technique and understanding of gamma shower discrimination methods, used the 10 m diameter telescope on Mount Hopkins in Arizona, and succeeded measuring a 9σ signal from the direction of Crab Nebula. As of today over 160 sources of gamma rays of very different types, of both galactic and extra-galactic origin, have been discovered due to this technique. This is a really fast evolving branch in science, rapidly improving our understanding of the most violent and energetic sources and processes in the sky. The study of these sources provides clues to many basic questions in astrophysics, astro-particle physics, physics of cosmic rays and cosmology. Today's telescopes, despite the young age of the technique, offer a solid performance. The technique is still maturing, leading to the next generation large instrument. This article is devoted to outlining the milestones in a long history that step-by-step have made this technique emerge and have brought about today's successful source hunting.

  14. High resolution Cerenkov light imaging of induced positron distribution in proton therapy

    SciTech Connect

    Yamamoto, Seiichi Fujii, Kento; Morishita, Yuki; Okumura, Satoshi; Komori, Masataka; Toshito, Toshiyuki

    2014-11-01

    Purpose: In proton therapy, imaging of the positron distribution produced by fragmentation during or soon after proton irradiation is a useful method to monitor the proton range. Although positron emission tomography (PET) is typically used for this imaging, its spatial resolution is limited. Cerenkov light imaging is a new molecular imaging technology that detects the visible photons that are produced from high-speed electrons using a high sensitivity optical camera. Because its inherent spatial resolution is much higher than PET, the authors can measure more precise information of the proton-induced positron distribution with Cerenkov light imaging technology. For this purpose, they conducted Cerenkov light imaging of induced positron distribution in proton therapy. Methods: First, the authors evaluated the spatial resolution of our Cerenkov light imaging system with a {sup 22}Na point source for the actual imaging setup. Then the transparent acrylic phantoms (100 × 100 × 100 mm{sup 3}) were irradiated with two different proton energies using a spot scanning proton therapy system. Cerenkov light imaging of each phantom was conducted using a high sensitivity electron multiplied charge coupled device (EM-CCD) camera. Results: The Cerenkov light’s spatial resolution for the setup was 0.76 ± 0.6 mm FWHM. They obtained high resolution Cerenkov light images of the positron distributions in the phantoms for two different proton energies and made fused images of the reference images and the Cerenkov light images. The depths of the positron distribution in the phantoms from the Cerenkov light images were almost identical to the simulation results. The decay curves derived from the region-of-interests (ROIs) set on the Cerenkov light images revealed that Cerenkov light images can be used for estimating the half-life of the radionuclide components of positrons. Conclusions: High resolution Cerenkov light imaging of proton-induced positron distribution was possible. The

  15. Advancing the Surveillance Capabilities of the Air Force’s Large-Aperature Telescopes

    DTIC Science & Technology

    2014-03-06

    added to these images to simulate the observed data. Since it is not fundamental, we do not include read noise from the detectors , assuming that... blind restorations for simulated data of a target of brightness mv=+2 as would be acquired with telescopes of 1 m (blue line), 1.6 m (magenta line...aperture diversity and blind deconvolution”, OSA topical meeting on Computational Optical Sensing and Imaging, Computational Imaging through Turbulence

  16. Utilizing the power of Cerenkov light with nanotechnology

    NASA Astrophysics Data System (ADS)

    Shaffer, Travis M.; Pratt, Edwin C.; Grimm, Jan

    2017-02-01

    The characteristic blue glow of Cerenkov luminescence (CL) arises from the interaction between a charged particle travelling faster than the phase velocity of light and a dielectric medium, such as water or tissue. As CL emanates from a variety of sources, such as cosmic events, particle accelerators, nuclear reactors and clinical radionuclides, it has been used in applications such as particle detection, dosimetry, and medical imaging and therapy. The combination of CL and nanoparticles for biomedicine has improved diagnosis and therapy, especially in oncological research. Although radioactive decay itself cannot be easily modulated, the associated CL can be through the use of nanoparticles, thus offering new applications in biomedical research. Advances in nanoparticles, metamaterials and photonic crystals have also yielded new behaviours of CL. Here, we review the physics behind Cerenkov luminescence and associated applications in biomedicine. We also show that by combining advances in nanotechnology and materials science with CL, new avenues for basic and applied sciences have opened.

  17. Cerenkov Radiator Driven by a Superconducting RF Electron Gun

    SciTech Connect

    Poole, B R; Harris, J R

    2011-03-07

    The Naval Postgraduate School (NPS), Niowave, Inc., and Boeing have recently demonstrated operation of the first superconducting RF electron gun based on a quarter wave resonator structure. In preliminary tests, this gun has produced 10 ps long bunches with charge in excess of 78 pC, and with beam energy up to 396 keV. Initial testing occurred at Niowave's Lansing, MI facility, but the gun and diagnostic beam line are planned for installation in California in the near future. The design of the diagnostic beam line is conducive to the addition of a Cerenkov radiator without interfering with other beam line operations. Design and simulations of a Cerenkov radiator, consisting of a dielectric lined waveguide will be presented. The dispersion relation for the structure is determined and the beam interaction is studied using numerical simulations. The characteristics of the microwave radiation produced in both the short and long bunch regimes will be presented.

  18. Unsupervised analysis of small animal dynamic Cerenkov luminescence imaging

    NASA Astrophysics Data System (ADS)

    Spinelli, Antonello E.; Boschi, Federico

    2011-12-01

    Clustering analysis (CA) and principal component analysis (PCA) were applied to dynamic Cerenkov luminescence images (dCLI). In order to investigate the performances of the proposed approaches, two distinct dynamic data sets obtained by injecting mice with 32P-ATP and 18F-FDG were acquired using the IVIS 200 optical imager. The k-means clustering algorithm has been applied to dCLI and was implemented using interactive data language 8.1. We show that cluster analysis allows us to obtain good agreement between the clustered and the corresponding emission regions like the bladder, the liver, and the tumor. We also show a good correspondence between the time activity curves of the different regions obtained by using CA and manual region of interest analysis on dCLIT and PCA images. We conclude that CA provides an automatic unsupervised method for the analysis of preclinical dynamic Cerenkov luminescence image data.

  19. Utilizing the power of Cerenkov light with nanotechnology.

    PubMed

    Shaffer, Travis M; Pratt, Edwin C; Grimm, Jan

    2017-02-07

    The characteristic blue glow of Cerenkov luminescence (CL) arises from the interaction between a charged particle travelling faster than the phase velocity of light and a dielectric medium, such as water or tissue. As CL emanates from a variety of sources, such as cosmic events, particle accelerators, nuclear reactors and clinical radionuclides, it has been used in applications such as particle detection, dosimetry, and medical imaging and therapy. The combination of CL and nanoparticles for biomedicine has improved diagnosis and therapy, especially in oncological research. Although radioactive decay itself cannot be easily modulated, the associated CL can be through the use of nanoparticles, thus offering new applications in biomedical research. Advances in nanoparticles, metamaterials and photonic crystals have also yielded new behaviours of CL. Here, we review the physics behind Cerenkov luminescence and associated applications in biomedicine. We also show that by combining advances in nanotechnology and materials science with CL, new avenues for basic and applied sciences have opened.

  20. Construction and testing of the SLD Cerenkov Ring Imaging Detector

    SciTech Connect

    Cavalli-Sforza, M.; Coyle, P.; Coyne, D.; Gagnon, P.; Williams, D.A.; Zucchelli, P. . Inst. for Particle Physics); Whitaker, J.S.; Wilson, R.J. . Dept. of Physics); Bean, A.; Caldwell, D.; Duboscq, J.; Huber, J.; Lu, A.; Mathys, L.; McHugh, S.; Morrison, R.; Witherell, M.; Yellin, S. . Dept. of Physics); Johns

    1990-01-01

    We report on the construction of the Cerenkov Ring Imaging Detector (CRID) for the SLD experiment at the SLAC Linear Collider and the testing of its components. We include results from testing the drift boxes, liquid radiator trays, and mirrors for the barrel CRID. We also discuss development of the support systems essential for the operation of the CRID: gas and liquid recirculator systems and monitoring. 15 refs., 9 figs.

  1. The Air Force Academy’s Falcon Telescope Network: An Educational and Research Network for K-12 and Higher Education

    NASA Astrophysics Data System (ADS)

    Chun, Francis; Tippets, Roger; Della-Rose, Devin J.; Polsgrove, Daniel; Gresham, Kimberlee; Barnaby, David A.

    2015-01-01

    The Falcon Telescope Network (FTN) is a global network of small aperture telescopes developed by the Center for Space Situational Awareness Research in the Department of Physics at the United States Air Force Academy (USAFA). Consisting of commercially available equipment, the FTN is a collaborative effort between USAFA and other educational institutions ranging from two- and four-year colleges to major research universities. USAFA provides the equipment (e.g. telescope, mount, camera, filter wheel, dome, weather station, computers and storage devices) while the educational partners provide the building and infrastructure to support an observatory. The user base includes USAFA along with K-12 and higher education faculty and students. The diversity of the users implies a wide variety of observing interests, and thus the FTN collects images on diverse objects, including satellites, galactic and extragalactic objects, and objects popular for education and public outreach. The raw imagery, all in the public domain, will be accessible to FTN partners and will be archived at USAFA. USAFA cadets use the FTN to continue a tradition of satellite characterization and astronomical research; this tradition is the model used for designing the network to serve undergraduate research needs. Additionally, cadets have led the development of the FTN by investigating observation priority schemes and conducting a 'day-in-the-life' study of the FTN in regards to satellite observations. With respect to K-12 outreach, cadets have provided feedback to K-12 students and teachers through evaluation of first-light proposals. In this paper, we present the current status of the network and results from student participation in the project.

  2. Cerenkov luminescence tomography based on preconditioning orthogonal matching pursuit

    NASA Astrophysics Data System (ADS)

    Liu, Haixiao; Hu, Zhenhua; Wang, Kun; Tian, Jie; Yang, Xin

    2015-03-01

    Cerenkov luminescence imaging (CLI) is a novel optical imaging method and has been proved to be a potential substitute of the traditional radionuclide imaging such as positron emission tomography (PET) and single-photon emission computed tomography (SPECT). This imaging method inherits the high sensitivity of nuclear medicine and low cost of optical molecular imaging. To obtain the depth information of the radioactive isotope, Cerenkov luminescence tomography (CLT) is established and the 3D distribution of the isotope is reconstructed. However, because of the strong absorption and scatter, the reconstruction of the CLT sources is always converted to an ill-posed linear system which is hard to be solved. In this work, the sparse nature of the light source was taken into account and the preconditioning orthogonal matching pursuit (POMP) method was established to effectively reduce the ill-posedness and obtain better reconstruction accuracy. To prove the accuracy and speed of this algorithm, a heterogeneous numerical phantom experiment and an in vivo mouse experiment were conducted. Both the simulation result and the mouse experiment showed that our reconstruction method can provide more accurate reconstruction result compared with the traditional Tikhonov regularization method and the ordinary orthogonal matching pursuit (OMP) method. Our reconstruction method will provide technical support for the biological application for Cerenkov luminescence.

  3. Simultaneous water vapor and dry air optical path length measurements and compensation with the large binocular telescope interferometer

    NASA Astrophysics Data System (ADS)

    Defrère, D.; Hinz, P.; Downey, E.; Böhm, M.; Danchi, W. C.; Durney, O.; Ertel, S.; Hill, J. M.; Hoffmann, W. F.; Mennesson, B.; Millan-Gabet, R.; Montoya, M.; Pott, J.-U.; Skemer, A.; Spalding, E.; Stone, J.; Vaz, A.

    2016-08-01

    The Large Binocular Telescope Interferometer uses a near-infrared camera to measure the optical path length variations between the two AO-corrected apertures and provide high-angular resolution observations for all its science channels (1.5-13 microns). There is however a wavelength dependent component to the atmospheric turbulence, which can introduce optical path length errors when observing at a wavelength different from that of the fringe sensing camera. Water vapor in particular is highly dispersive and its effect must be taken into account for high-precision infrared interferometric observations as described previously for VLTI/MIDI or the Keck Interferometer Nuller. In this paper, we describe the new sensing approach that has been developed at the LBT to measure and monitor the optical path length fluctuations due to dry air and water vapor separately. After reviewing the current performance of the system for dry air seeing compensation, we present simultaneous H-, K-, and N-band observations that illustrate the feasibility of our feedforward approach to stabilize the path length fluctuations seen by the LBTI nuller.

  4. Application of Cerenkov radiation generated in plastic optical fibers for therapeutic photon beam dosimetry.

    PubMed

    Jang, Kyoung Won; Yagi, Takahiro; Pyeon, Cheol Ho; Yoo, Wook Jae; Shin, Sang Hun; Jeong, Chiyoung; Min, Byung Jun; Shin, Dongho; Misawa, Tsuyoshi; Lee, Bongsoo

    2013-02-01

    A Cerenkov fiber-optic dosimeter (CFOD) is fabricated using plastic optical fibers to measure Cerenkov radiation induced by a therapeutic photon beam. We measured the Cerenkov radiation generated in optical fibers in various irradiation conditions to evaluate the usability of Cerenkov radiation for a photon beam therapy dosimetry. As a results, the spectral peak of Cerenkov radiation was measured at a wavelength of 515 nm, and the intensity of Cerenkov radiation increased linearly with increasing irradiated length of the optical fiber. Also, the intensity peak of Cerenkov radiation was measured in the irradiation angle range of 30 to 40 deg. In the results of Monte Carlo N-particle transport code simulations, the relationship between fluxes of electrons over Cerenkov threshold energy and energy deposition of a 6 MV photon beam had a nearly linear trend. Finally, percentage depth doses for the 6 MV photon beam could be obtained using the CFOD and the results were compared with those of an ionization chamber. Here, the mean dose difference was about 0.6%. It is anticipated that the novel and simple CFOD can be effectively used for measuring depth doses in radiotherapy dosimetry.

  5. Development and construction of the SLD Cerenkov Ring Imaging Detector

    SciTech Connect

    Aston, D.; Bean, A.; Bienz, T.; Bird, F.; Caldwell, D.; Cavalli-Sforza, M.; Coyle, P.; Coyne, D.; Dasu, S.; Dunwoodie, W.

    1989-06-01

    We report on the development and construction of the Cerenkov Ring Imaging Detector (CRID) for the SLD experiment at the SLAC linear collider. In particular, we outline recent progress in the construction, and results from testing the first components of the barrel CRID, including the drift boxes, liquid radiator trays and mirror system. We also review progress in the construction of the barrel CRID gas radiator vessel, the liquid radiator recirculator system, and the electronic readout system. The development of a comprehensive monitor and control system -- upon which the stable operation and physics efficacy of the CRID depend -- is also described. 19 refs., 9 figs.

  6. High gain multigap avalanche detectors for Cerenkov ring imaging

    SciTech Connect

    Gilmore, R.S.; Lavender, W.M.; Leith, D.W.G.S.; Williams, S.H.

    1980-10-01

    We report on a continuing study of multigap parallel plate avalanche chambers, primarily as photoelectron detectors for use with Cerenkov ring imaging counters. By suitable control of the fields in successive gaps and by introducing screens to reduce photon feedback to the cathode the gain many be increased considerably. We have obtained gains in excess of 6 x 10/sup 7/ for photoelectrons with a good pulse height spectrum and expect to increase this further. We discuss the use of resistive anodes to give avalanche positions in two dimensions by charge division.

  7. Kinetic analysis of two dimensional metallic grating Cerenkov maser

    SciTech Connect

    Zhao Ding

    2011-08-15

    The dispersion relation of two dimensional metallic grating Cerenkov maser has been given by using kinetic analysis, in which the influence of electron movement is directly considered without using an equivalent dielectric medium assumption. The effects of structural parameters and beam state on the interaction gain and synchronous frequency have also been investigated in detail by numerical calculations. To an illustrative case, the quantitative relations produced from varying the gap distance between electron beam and metallic grating, beam current, electron transverse to axial velocity ratio, and electron axial velocity spread have been obtained. The developed method can be used to predict the real interaction system performances.

  8. Gadolinium-doped water cerenkov-based neutron and high energy gamma-ray detector and radiation portal monitoring system

    DOEpatents

    Dazeley, Steven A; Svoboda, Robert C; Bernstein, Adam; Bowden, Nathaniel

    2013-02-12

    A water Cerenkov-based neutron and high energy gamma ray detector and radiation portal monitoring system using water doped with a Gadolinium (Gd)-based compound as the Cerenkov radiator. An optically opaque enclosure is provided surrounding a detection chamber filled with the Cerenkov radiator, and photomultipliers are optically connected to the detect Cerenkov radiation generated by the Cerenkov radiator from incident high energy gamma rays or gamma rays induced by neutron capture on the Gd of incident neutrons from a fission source. The PMT signals are then used to determine time correlations indicative of neutron multiplicity events characteristic of a fission source.

  9. Van Der Pol model of a Cerenkov maser

    SciTech Connect

    Kleckner, M.; Ron, A.; Botton, M.

    1995-12-31

    A non-linear analysis of a Cerenkov maser is presented. The system consists of a ring configuration of a cylindrical waveguide filled with a dielectric material. A single transverse-magnetic mode is assumed to propagate in the system. A low-density pencil electron beam travels in part of the ring, confined by a strong axial magnetic field. Using the single-particle description for the beam and the wave equation for the field, we obtain a set of two coupled non-linear differential equations describing the slowly varying amplitude and phase of the electromagnetic mode. The gain per path is assumed to be small and the spatial growth of the field is neglected. The resulting time dependent amplitude includes the exponential gain of the linear stage and the saturation to its maximum value. The time dependent frequency is also calculated. The two equations are combined to a single Van Der Pol equation with a non-linear restoring force. This description demonstrates the similarities and differences between the Cerenkov maser and other lasing systems.

  10. Detection of the isotopes of heavy cosmic ray nuclei. [by particle counter telescope

    NASA Technical Reports Server (NTRS)

    Gilman, C. M.; Waddington, C. J.

    1975-01-01

    A counter telescope designed to detect and resolve the isotopic composition of cosmic ray nuclei heavier than neon is being prepared. The telescope consists of a rather conventional charge measuring array using two scintillator elements and two solid Cerenkov radiators of differing refractive index. The mass measurement is obtained by combining the velocity information from one or both of the Cerenkov radiators operating near their threshold with residual range measured in a block of nuclear emulsion. Path length corrections and particle location in the emulsions is provided by a spark chamber fired in coincidence with potentially suitable particles. The telescope has a geometry factor of 530 sq cm sr roughly. It should be able to resolve the isotopes of iron over the energy range of 300 to 720 Mev/n and those of neon over 300 to 400 MeV/n. The expected response and characteristics of the telescope are described in detail and the sensitivity to rare isotopes discussed.

  11. Fibre-optic gamma-flux monitoring in a fission reactor by means of Cerenkov radiation

    NASA Astrophysics Data System (ADS)

    Brichard, B.; Fernandez, A. F.; Ooms, H.; Berghmans, F.

    2007-10-01

    We demonstrate the possibility of using Cerenkov radiation to monitor the reactor power and the high energy gamma-ray flux in a high neutron flux reactor. The system employs a radiation-resistant pure silica glass fibre to measure the Cerenkov radiation in the infrared region (800-1100 nm). A model is proposed to determine the order of magnitude of the gamma-ray flux from the measurement. The method and concept can be extended to the monitoring of low reactor powers if Cerenkov radiation is measured in the 450-500 nm region by means of hydrogen-treated fibres.

  12. Cerenkov and radioluminescence imaging of brain tumor specimens during neurosurgery

    NASA Astrophysics Data System (ADS)

    Spinelli, Antonello Enrico; Schiariti, Marco P.; Grana, Chiara M.; Ferrari, Mahila; Cremonesi, Marta; Boschi, Federico

    2016-05-01

    We presented the first example of Cerenkov luminescence imaging (CLI) and radioluminescence imaging (RLI) of human tumor specimens. A patient with a brain meningioma localized in the left parietal region was injected with 166 MBq of Y90-DOTATOC the day before neurosurgery. The specimens of the tumor removed during surgery were imaged using both CLI and RLI using an optical imager prototype developed in our laboratory. The system is based on a cooled electron multiplied charge coupled device coupled with an f/0.95 17-mm C-mount lens. We showed for the first time the possibility of obtaining CLI and RLI images of fresh human brain tumor specimens removed during neurosurgery.

  13. Quantitative modeling of Cerenkov light production efficiency from medical radionuclides.

    PubMed

    Beattie, Bradley J; Thorek, Daniel L J; Schmidtlein, Charles R; Pentlow, Keith S; Humm, John L; Hielscher, Andreas H

    2012-01-01

    There has been recent and growing interest in applying Cerenkov radiation (CR) for biological applications. Knowledge of the production efficiency and other characteristics of the CR produced by various radionuclides would help in accessing the feasibility of proposed applications and guide the choice of radionuclides. To generate this information we developed models of CR production efficiency based on the Frank-Tamm equation and models of CR distribution based on Monte-Carlo simulations of photon and β particle transport. All models were validated against direct measurements using multiple radionuclides and then applied to a number of radionuclides commonly used in biomedical applications. We show that two radionuclides, Ac-225 and In-111, which have been reported to produce CR in water, do not in fact produce CR directly. We also propose a simple means of using this information to calibrate high sensitivity luminescence imaging systems and show evidence suggesting that this calibration may be more accurate than methods in routine current use.

  14. Cerenkov luminescence imaging of human breast cancer: a Monte Carlo simulations study

    NASA Astrophysics Data System (ADS)

    Boschi, F.; Pagliazzi, M.; Spinelli, A. E.

    2016-03-01

    Cerenkov luminescence imaging (CLI) is a novel molecular imaging technique based on the detection of Cerenkov light produced by beta particles traveling through biological tissues. In this paper we simulated using 18F and 90Y the possibility of detecting Cerenkov luminescence in human breast tissues, in order to evaluate the potential of the CLI technique in a clinical setting. A human breast digital phantom was obtained from an 18F-FDG CT-PET scan. The spectral features of the breast surface emission were obtained as well as the simulated images obtainable by a cooled CCD detector. The simulated images revealed a signal to noise ratio equal to 6 for a 300 s of acquisition time. We concluded that a dedicated human Cerenkov imaging detector can be designed in order to offer a valid low cost alternative to diagnostic techniques in nuclear medicine, in particular allowing the detection of beta-minus emitters used in radiotherapy.

  15. Removing Noises Induced by Gamma Radiation in Cerenkov Luminescence Imaging Using a Temporal Median Filter

    PubMed Central

    Li, Yang; Zhan, Yonghua; Kang, Fei; Wang, Jing

    2016-01-01

    Cerenkov luminescence imaging (CLI) can provide information of medical radionuclides used in nuclear imaging based on Cerenkov radiation, which makes it possible for optical means to image clinical radionuclide labeled probes. However, the exceptionally weak Cerenkov luminescence (CL) from Cerenkov radiation is susceptible to lots of impulse noises introduced by high energy gamma rays generating from the decays of radionuclides. In this work, a temporal median filter is proposed to remove this kind of impulse noises. Unlike traditional CLI collecting a single CL image with long exposure time and smoothing it using median filter, the proposed method captures a temporal sequence of CL images with shorter exposure time and employs a temporal median filter to smooth a temporal sequence of pixels. Results of in vivo experiments demonstrated that the proposed temporal median method can effectively remove random pulse noises induced by gamma radiation and achieve a robust CLI image. PMID:27648450

  16. Cosmic ray studies with a gas Cerenkov counter in association with an ionization spectrometer

    NASA Technical Reports Server (NTRS)

    Balasubrahmanyan, V. K.; Ormes, J. F.; Arens, J. F.; Siohan, F.; Simon, M.; Spiegelhauer, H.; Yodh, G. B.

    1980-01-01

    The results from a balloon-borne gas Cerenkov counter (threshold 16.5 GeV/nuc) and an ionization spectrometer are presented. The gas Cerenkov counter provides an absolute energy calibration for the response of the calorimeter for the Z range of 5-26 nuclei of cosmic rays. The contribution of scintillation to the gas Cerenkov pulse height has been obtained by independently selecting particles below the gas Cerenkov threshold using the ionization spectrometer. Energy spectra were derived by minimizing the chi-squared between a Monte Carlo simulated data and flight data. Best fit power laws were determined for C, N, O, Ne, Mg, and Si. The power laws, all consistent with E exp-2.7, are not good fits to the data. A better fit is obtained using the spectrum derived from the spectrometer.

  17. SNM Detection with a Large Water Cerenkov Detector

    SciTech Connect

    Dazeley, S; Bernstein, A; Bowden, N; Ouedraogo, S; Svoboda, R; Sweeny, M

    2009-06-04

    Special Nuclear Material (SNM) can either spontaneously fission, or be induced to do so. Either case results in neutron emission. Since neutrons are highly penetrating and difficult to shield, they could, potentially, be detected escaping even a well shielded cargo container. Obviously, if the shielding is sophisticated, detecting it would require a highly efficient detector with close to 4{pi} solid angle coverage. Water Cerenkov detectors may be a cost effective way to achieve that goal if it can be shown that the neutron capture signature is large enough and if sufficient background rejection can be employed as detectors get larger. In 2008 the LLNL Advanced Detector Group reported the successful detection of neutrons with a 1/4 ton gadolinium doped water Cerenkov prototype. We have now built a 4 ton version. This detector is not only bigger, it was designed with photon detection efficiency in mind from the beginning. We are employing increased photocathode coverage and more reflective walls, coated with PTFE. The increased efficiency should allow better energy resolution. We expect that the better diffusive wall reflectivity will reduce the overall dependence of the detector response on particle direction, again producing a more consistent response. We also believe that as detectors get larger, both uncorrelated and correlated backgrounds due to gamma-rays and cosmic ray interactions near the detector will increase. To prove the effectiveness of the technology we must develop new ways to reject these backgrounds while maintaining our sensitivity to SNM neutrons. Better energy resolution will enable us to reject more of the low energy gamma-ray backgrounds on this basis. Overcoming cosmic ray induced neutrons is perhaps an even larger concern as detectors get larger. Our detector is designed so that we can test various segmentation schemes - effectively dividing the detector up into smaller ones. In this presentation, we will describe our detector in detail.

  18. Cerenkov specific contrast agents for detection of pH in vivo

    PubMed Central

    Czupryna, Julie; Kachur, Alexander V.; Blankemeyer, Eric; Popov, Anatoliy V.; Karp, Joel S.; Delikatny, E. James

    2015-01-01

    We report the design, testing and in vivo application of pH sensitive contrast agents designed specifically for Cerenkov imaging. Radioisotopes used for positron emission tomography (PET) emit photons via Cerenkov radiation. The multispectral emission of Cerenkov radiation allows for selective bandwidth quenching, where a band of photons are quenched by absorption by a functional dye. Under acidic conditions, 18F-labeled derivatives emit the full spectrum of Cerenkov light. Under basic conditions, the dyes change color and a wavelength-dependent quenching of Cerenkov emission is observed. METHODS Mono and di-18F-labeled derivatives of phenolsulfonphthalein (phenol red) and meta-cresolsulfonphthalein (cresol purple) were synthesized by electrophilic fluorination. Cerenkov emission was measured at different wavelengths as a function of pH in vitro. Intramolecular response was measured in fluorinated probes; intermolecular quenching by mixing phenolphthalein with 18F FDG. Monofluorocresol purple (MFCP) was tested in mice treated with acetazolamide to cause urinary alkalinization and Cerenkov images compared to PET images. RESULTS Fluorinated pH indicators were produced with radiochemical yields of 4-11% at >90% purity. Selective Cerenkov quenching was observed intramolecularly with difluorophenol red or MFCP, and intermolecularly in phenolphthalein 18F-FDG mixtures. The probes were selectively quenched in the bandwidth closest to the indicator’s absorption maximum (λmax) at pHs above the indicator pKa. Addition of acid or base to the probes resulted in reversible switching from unquenched to quenched emission. In vivo, the bladders of acetazolamide-treated mice exhibited a wavelength-dependent quenching in Cerenkov emission, with the greatest reduction occurring near the λmax. Ratiometric imaging at two wavelengths showed significant decreases in Cerenkov emission at basic pH and allowed the estimation of absolute pH in vivo. CONCLUSIONS We have created contrast

  19. The University of Durham Mark 3 very high energy gamma ray telescope

    NASA Technical Reports Server (NTRS)

    Chadwick, P. M.; Dipper, N. A.; Dowthwaite, J. C.; Kirkman, I. W.; Mccomb, T. J.; Orford, K. J.; Turver, K. E.

    1985-01-01

    A new very high energy gamma-ray telescope employing the atmospheric Cerenkov light technique and currently nearing completion is described. The telescope is designed to have capability as both a wide angle instrument (4 degree field of view) for sky survey work and as a narrow field of view instrument (1.35 degrees) for conventional drift-scanning and tracking modes of operation. The telescope consists of two 10 sq. m. mirrors operated in fast coincidence with multiple phototube assemblies at the prime focus of each mirror. The design philosophy of the instrument is discussed and comparisons of its performance with our previous telescopes are made.

  20. Measurement of therapeutic photon beams-induced Cerenkov radiation generated in PMMA- and PS-based plastic optical fibers

    NASA Astrophysics Data System (ADS)

    Lee, Bongsoo; Shin, Sang Hun; Yoo, Wook Jae; Jang, Kyoung Won

    2016-10-01

    In this study, we characterized Cerenkov radiation generated in polystyrene (PS)- and polymethyl methacrylate (PMMA)-based plastic optical fibers (POFs) to select an adequate optical fiber for producing Cerenkov radiation. To determine the relationship between the absorbed dose and the intensity of Cerenkov radiation, we calculated the energy depositions of photon beams and fluxes of electrons inducing Cerenkov radiation using the Monte Carlo N-Particle eXtended code. Also, intensities of Cerenkov radiation generated in PS- and PMMA-based POFs were measured as functions of dose rate and monitor unit. At last, therapeutic photon beams-induced Cerenkov radiation in PS- and PMMA-based POFs was measured according to depths of solid water phantom.

  1. Spectral method for the correction of the Cerenkov light effect in plastic scintillation detectors: A comparison study of calibration procedures and validation in Cerenkov light-dominated situations

    SciTech Connect

    Guillot, Mathieu; Gingras, Luc; Archambault, Louis; Beddar, Sam; Beaulieu, Luc

    2011-04-15

    Purpose: The purposes of this work were: (1) To determine if a spectral method can accurately correct the Cerenkov light effect in plastic scintillation detectors (PSDs) for situations where the Cerenkov light is dominant over the scintillation light and (2) to develop a procedural guideline for accurately determining the calibration factors of PSDs. Methods: The authors demonstrate, by using the equations of the spectral method, that the condition for accurately correcting the effect of Cerenkov light is that the ratio of the two calibration factors must be equal to the ratio of the Cerenkov light measured within the two different spectral regions used for analysis. Based on this proof, the authors propose two new procedures to determine the calibration factors of PSDs, which were designed to respect this condition. A PSD that consists of a cylindrical polystyrene scintillating fiber (1.6 mm{sup 3}) coupled to a plastic optical fiber was calibrated by using these new procedures and the two reference procedures described in the literature. To validate the extracted calibration factors, relative dose profiles and output factors for a 6 MV photon beam from a medical linac were measured with the PSD and an ionization chamber. Emphasis was placed on situations where the Cerenkov light is dominant over the scintillation light and on situations dissimilar to the calibration conditions. Results: The authors found that the accuracy of the spectral method depends on the procedure used to determine the calibration factors of the PSD and on the attenuation properties of the optical fiber used. The results from the relative dose profile measurements showed that the spectral method can correct the Cerenkov light effect with an accuracy level of 1%. The results obtained also indicate that PSDs measure output factors that are lower than those measured with ionization chambers for square field sizes larger than 25x25 cm{sup 2}, in general agreement with previously published Monte

  2. A multivariate analysis approach for the Imaging Atmospheric Cerenkov Telescopes System H.E.S.S

    SciTech Connect

    Dubois, F.; Lamanna, G.

    2008-12-24

    We present a multivariate classification approach applied to the analysis of data from the H.E.S.S. Very High Energy (VHE){gamma}-ray IACT stereoscopic system. This approach combines three complementary analysis methods already successfully applied in the H.E.S.S. data analysis. The proposed approach, with the combined effective estimator X{sub eff}, is conceived to improve the signal-to-background ratio and therefore particularly relevant to the morphological studies of faint extended sources.

  3. SU-E-T-238: Monte Carlo Estimation of Cerenkov Dose for Photo-Dynamic Radiotherapy

    SciTech Connect

    Chibani, O; Price, R; Ma, C; Eldib, A; Mora, G

    2014-06-01

    Purpose: Estimation of Cerenkov dose from high-energy megavoltage photon and electron beams in tissue and its impact on the radiosensitization using Protoporphyrine IX (PpIX) for tumor targeting enhancement in radiotherapy. Methods: The GEPTS Monte Carlo code is used to generate dose distributions from 18MV Varian photon beam and generic high-energy (45-MV) photon and (45-MeV) electron beams in a voxel-based tissueequivalent phantom. In addition to calculating the ionization dose, the code scores Cerenkov energy released in the wavelength range 375–425 nm corresponding to the pick of the PpIX absorption spectrum (Fig. 1) using the Frank-Tamm formula. Results: The simulations shows that the produced Cerenkov dose suitable for activating PpIX is 4000 to 5500 times lower than the overall radiation dose for all considered beams (18MV, 45 MV and 45 MeV). These results were contradictory to the recent experimental studies by Axelsson et al. (Med. Phys. 38 (2011) p 4127), where Cerenkov dose was reported to be only two orders of magnitude lower than the radiation dose. Note that our simulation results can be corroborated by a simple model where the Frank and Tamm formula is applied for electrons with 2 MeV/cm stopping power generating Cerenkov photons in the 375–425 nm range and assuming these photons have less than 1mm penetration in tissue. Conclusion: The Cerenkov dose generated by high-energy photon and electron beams may produce minimal clinical effect in comparison with the photon fluence (or dose) commonly used for photo-dynamic therapy. At the present time, it is unclear whether Cerenkov radiation is a significant contributor to the recently observed tumor regression for patients receiving radiotherapy and PpIX versus patients receiving radiotherapy only. The ongoing study will include animal experimentation and investigation of dose rate effects on PpIX response.

  4. SU-E-QI-15: Single Point Dosimetry by Means of Cerenkov Radiation Energy Transfer (CRET)

    SciTech Connect

    Volotskova, O; Jenkins, C; Xing, L

    2014-06-15

    Purpose: Cerenkov light is generated when a charged particles with energy greater then 250 keV, moves faster than the speed of light in a given medium. Both x-ray photons and electrons produce optical Cerenkov photons during the static megavoltage linear accelerator (LINAC) operational mode. Recently, Cerenkov radiation gained considerable interest as possible candidate as a new imaging modality. Optical signals generated by Cerenkov radiation may act as a surrogate for the absorbed superficial radiation dose. We demonstrated a novel single point dosimetry method for megavoltage photon and electron therapy utilizing down conversion of Cerenkov photons. Methods: The custom build signal characterization system was used: a sample holder (probe) with adjacent light tight compartments was connected via fiber-optic cables to a photon counting photomultiplier tube (PMT). One compartment contains a medium only while the other contains medium and red-shifting nano-particles (Q-dots, nanoclusters). By taking the difference between the two signals (Cerenkov photons and CRET photons) we obtain a measure of the down-converted light, which we expect to be proportional to dose as measured with an adjacent ion chamber. Experimental results are compared to Monte Carlo simulations performed using the GEANT4 code. Results: The signal correlation between CR signal, CRET readings and dose produced by LINAC at a single point were investigated. The experimental results were compared with simulations. The dose linearity, signal to noise ratio and dose rate dependence were tested with custom build CRET based probe. Conclusion: Performance characteristics of the proposed single point CRET based probe were evaluated. The direct use of the induced Cerenkov emission and CRET in an irradiated single point volume as an indirect surrogate for the imparted dose was investigated. We conclude that CRET is a promising optical based dosimetry method that offers advantages over those already proposed.

  5. Space Telescope.

    ERIC Educational Resources Information Center

    National Aeronautics and Space Administration, Huntsville, AL. George C. Marshall Space Flight Center.

    This pamphlet describes the Space Telescope, an unmanned multi-purpose telescope observatory planned for launch into orbit by the Space Shuttle in the 1980s. The unique capabilities of this telescope are detailed, the major elements of the telescope are described, and its proposed mission operations are outlined. (CS)

  6. Fiber optic Cerenkov radiation sensor system to estimate burn-up of spent fuel: characteristic evaluation of the system using Co-60 source

    NASA Astrophysics Data System (ADS)

    Shin, S. H.; Jang, K. W.; Jeon, D.; Hong, S.; Kim, S. G.; Sim, H. I.; Yoo, W. J.; Park, B. G.; Lee, B.

    2013-09-01

    Cerenkov radiation occurs when charged particles are moving faster than the speed of light in a transparent dielectric medium. In optical fibers, the Cerenkov light also can be generated due to their dielectric components. Accordingly, the radiation-induced light signals can be obtained using optical fibers without any scintillating material. In this study, to measure the intensities of Cerenkov radiation induced by gamma-rays, we have fabricated the fiber-optic Cerenkov radiation sensor system using silica optical fibers, plastic optical fibers, multi-anode photomultiplier tubes, and a scanning system. To characterize the Cerenkov radiation generated in optical fibers, the spectra of Cerenkov radiation generated in the silica and plastic optical fibers were measured. Also, the intensities of Cerenkov radiation induced by gamma-rays generated from a cylindrical Co-60 source with or without lead shielding were measured using the fiberoptic Cerenkov radiation sensor system.

  7. Quantitative Modeling of Cerenkov Light Production Efficiency from Medical Radionuclides

    PubMed Central

    Beattie, Bradley J.; Thorek, Daniel L. J.; Schmidtlein, Charles R.; Pentlow, Keith S.; Humm, John L.; Hielscher, Andreas H.

    2012-01-01

    There has been recent and growing interest in applying Cerenkov radiation (CR) for biological applications. Knowledge of the production efficiency and other characteristics of the CR produced by various radionuclides would help in accessing the feasibility of proposed applications and guide the choice of radionuclides. To generate this information we developed models of CR production efficiency based on the Frank-Tamm equation and models of CR distribution based on Monte-Carlo simulations of photon and β particle transport. All models were validated against direct measurements using multiple radionuclides and then applied to a number of radionuclides commonly used in biomedical applications. We show that two radionuclides, Ac-225 and In-111, which have been reported to produce CR in water, do not in fact produce CR directly. We also propose a simple means of using this information to calibrate high sensitivity luminescence imaging systems and show evidence suggesting that this calibration may be more accurate than methods in routine current use. PMID:22363636

  8. Spectral discrimination of Cerenkov radiation in scintillating dosimeters.

    PubMed

    Frelin, A M; Fontbonne, J M; Ban, G; Colin, J; Labalme, M; Batalla, A; Isambert, A; Vela, A; Leroux, T

    2005-09-01

    Radiation therapy accelerators require highly accurate dose deposition and the output must be monitored frequently and regularly. Ionization chambers are the primary tool for this control, but their size, their high voltage needed, and the correction needed for electrons make them unsuitable for use during patient treatment. We have developed a small (1-mm-diam and 1-mm-long active part), flexible, and water-equivalent dosimeter. It is suitable for photon and electron beams without corrections, and performs on line dose measurements. This detector is based on only one scintillating fiber and a CCD camera. A new signal processing is used to remove the effect of Cerenkov radiation background, which only requires a preliminary calibration. Central-axis depth-dose distribution comparisons have been achieved with standard ionization chambers, over a range from 8 to 25 MV photons and from 6 to 21 MeV electrons in order to validate this calibration. Results show a very good agreement, with less than 1% difference between the two detectors.

  9. Development of gamma-photon/Cerenkov-light hybrid system for simultaneous imaging of I-131 radionuclide

    NASA Astrophysics Data System (ADS)

    Yamamoto, Seiichi; Suzuki, Mayumi; Kato, Katsuhiko; Watabe, Tadashi; Ikeda, Hayato; Kanai, Yasukazu; Ogata, Yoshimune; Hatazawa, Jun

    2016-09-01

    Although iodine 131 (I-131) is used for radionuclide therapy, high resolution images are difficult to obtain with conventional gamma cameras because of the high energy of I-131 gamma photons (364 keV). Cerenkov-light imaging is a possible method for beta emitting radionuclides, and I-131 (606 MeV maximum beta energy) is a candidate to obtain high resolution images. We developed a high energy gamma camera system for I-131 radionuclide and combined it with a Cerenkov-light imaging system to form a gamma-photon/Cerenkov-light hybrid imaging system to compare the simultaneously measured images of these two modalities. The high energy gamma imaging detector used 0.85-mm×0.85-mm×10-mm thick GAGG scintillator pixels arranged in a 44×44 matrix with a 0.1-mm thick reflector and optical coupled to a Hamamatsu 2 in. square position sensitive photomultiplier tube (PSPMT: H12700 MOD). The gamma imaging detector was encased in a 2 cm thick tungsten shield, and a pinhole collimator was mounted on its top to form a gamma camera system. The Cerenkov-light imaging system was made of a high sensitivity cooled CCD camera. The Cerenkov-light imaging system was combined with the gamma camera using optical mirrors to image the same area of the subject. With this configuration, we simultaneously imaged the gamma photons and the Cerenkov-light from I-131 in the subjects. The spatial resolution and sensitivity of the gamma camera system for I-131 were respectively 3 mm FWHM and 10 cps/MBq for the high sensitivity collimator at 10 cm from the collimator surface. The spatial resolution of the Cerenkov-light imaging system was 0.64 mm FWHM at 10 cm from the system surface. Thyroid phantom and rat images were successfully obtained with the developed gamma-photon/Cerenkov-light hybrid imaging system, allowing direct comparison of these two modalities. Our developed gamma-photon/Cerenkov-light hybrid imaging system will be useful to evaluate the advantages and disadvantages of these two

  10. Measurements of longitudinal gamma ray distribution using a multichannel fiber-optic Cerenkov radiation sensor

    NASA Astrophysics Data System (ADS)

    Shin, S. H.; Jeon, D.; Kim, J. S.; Jang, J. S.; Jang, K. W.; Yoo, W. J.; Moon, J. H.; Park, B. G.; Kim, S.; Lee, B.

    2014-11-01

    Cerenkov radiation occurs when charged particles are moving faster than the speed of light in a transparent dielectric medium. In optical fibers, Cerenkov radiation can also be generated due to the fiber’s dielectric components. Accordingly, the radiation-induced light signals can be obtained using the optical fibers without any scintillating material. In this study, we fabricated a multichannel, fiber-optic Cerenkov radiation sensor (FOCRS) system using silica optical fibers (SOFs), plastic optical fibers (POFs), an optical spectrometer, multi-anode photomultiplier tubes (MA-PMTs) and a scanning system to measure the light intensities of Cerenkov radiation induced by gamma rays. To evaluate the fading effects in optical fibers, the spectra of Cerenkov radiation generated in the SOFs and POFs were measured based on the irradiation time by using an optical spectrometer. In addition, we measured the longitudinal distribution of gamma rays emitted from the cylindrical type Co-60 source by using MA-PMTs. The result was also compared with the distribution of the electron flux calculated by using the Monte Carlo N-particle transport code (MCNPX).

  11. Intensity Enhanced Cerenkov Luminescence Imaging Using Terbium-Doped Gd2O2S Microparticles.

    PubMed

    Cao, Xin; Chen, Xueli; Kang, Fei; Zhan, Yonghua; Cao, Xu; Wang, Jing; Liang, Jimin; Tian, Jie

    2015-06-10

    Weak intensity and poor penetration depth are two big obstacles toward clinical use of Cerenkov luminescence imaging (CLI). In this proof-of-concept study, we overcame these limitations by using lanthanides-based radioluminescent microparticles (RLMPs), called terbium doped Gd2O2S. The characterization experiment showed that the emission excited by Cerenkov luminescence can be neglected whereas the spectrum experiment demonstrated that the RLMPs can actually be excited by γ-rays. A series of in vitro experiments demonstrated that RLMPs significantly improve the intensity and the penetration capacity of CLI, which has been extended to as deep as 15 mm. In vivo pseudotumor study further prove the huge potential of this enhancement strategy for Cerenkov luminescence imaging in living animal studies.

  12. Cerenkov light spectrum in an optical fiber exposed to a photon or electron radiation therapy beam

    SciTech Connect

    Lambert, Jamil; Yin Yongbai; McKenzie, David R.; Law, Sue; Suchowerska, Natalka

    2009-06-20

    A Cerenkov signal is generated when energetic charged particles enter the core of an optical fiber. The Cerenkov intensity can be large enough to interfere with signals transmitted through the fiber. We determine the spectrum of the Cerenkov background signal generated in a poly(methyl methacrylate) optical fiber exposed to photon and electron therapeutic beams from a linear accelerator. This spectral measurement is relevant to discrimination of the signal from the background, as in scintillation dosimetry using optical fiber readouts. We find that the spectrum is approximated by the theoretical curve after correction for the wavelength dependent attenuation of the fiber. The spectrum does not depend significantly on the angle between the radiation beam and the axis of the fiber optic but is dependent on the depth in water at which the fiber is exposed to the beam.

  13. Feasibility of fiber-optic radiation sensor using Cerenkov effect for detecting thermal neutrons.

    PubMed

    Jang, Kyoung Won; Yagi, Takahiro; Pyeon, Cheol Ho; Yoo, Wook Jae; Shin, Sang Hun; Misawa, Tsuyoshi; Lee, Bongsoo

    2013-06-17

    In this research, we propose a novel method for detecting thermal neutrons with a fiber-optic radiation sensor using the Cerenkov effect. We fabricate a fiber-optic radiation sensor that detects thermal neutrons with a Gd-foil, a rutile crystal, and a plastic optical fiber. The relationship between the fluxes of electrons inducing Cerenkov radiation in the sensor probe of the fiber-optic radiation sensor and thermal neutron fluxes is determined using the Monte Carlo N-particle transport code simulations. To evaluate the fiber-optic radiation sensor, the Cerenkov radiation generated in the fiber-optic radiation sensor by irradiation of pure thermal neutron beams is measured according to the depths of polyethylene.

  14. Space Telescopes

    NASA Technical Reports Server (NTRS)

    Clampin, Mark; Flanagan, Kathryn A.

    2012-01-01

    Space telescopes have been a dominant force in astrophysics and astronomy over the last two decades. As Lyman Spitzer predicted in 1946, space telescopes have opened up much of the electromagnetic spectrum to astronomers, and provided the opportunity to exploit the optical performance of telescopes uncompromised by the turbulent atmosphere. This special section of Optical Engineering is devoted to space telescopes. It focuses on the design and implementation of major space observatories from the gamma-ray to far-infrared, and highlights the scientific and technical breakthroughs enabled by these telescopes. The papers accepted for publication include reviews of major space telescopes spanning the last two decades, in-depth discussions of the design considerations for visible and x-ray telescopes, and papers discussing concepts and technical challenges for future space telescopes.

  15. Optical imaging of Cerenkov light generation from positron-emitting radiotracers

    PubMed Central

    Robertson, R; Germanos, M S; Li, C; Mitchell, G S; Cherry, S R; Silva, M D

    2009-01-01

    Radiotracers labeled with high-energy positron-emitters, such as those commonly used for positron emission tomography (PET) studies, emit visible light immediately following decay in a medium. This phenomenon, not previously described for these imaging tracers, is consistent with Cerenkov radiation and has several potential applications, especially for in vivo molecular imaging studies. Herein we detail a new molecular imaging tool, Cerenkov Luminescence Imaging, the experiments conducted that support our interpretation of the source of the signal, and proof-of-concept in vivo studies that set the foundation for future application of this new method. PMID:19636082

  16. Role of Cerenkov radiation in the eye-flashes observed by Apollo astronauts.

    PubMed

    McNulty, P J; Pease, V P; Bond, V P

    1976-01-01

    Visual phenomena in the form of colorless flashes of light were observed by astronauts in deep space when their eyes were closed and adapted to darkness. We describe in this paper laboratory experiments and calculations which indicate that many of these flashes are the result of visible light generated within the astronauts' eyeball in the form of Cerenkov radiation when a relativistic HZE particle traverses it. The sensitivity to Cerenkov radiation measured for three subjects exposed to pulses of pions and muons and the visual phenomena observed were found to be consistent with the reports of flashes observed at rates as high as 2 per minute on Apollo missions 11 through 17.

  17. The History of Ground-Based Very High Energy Gamma-Ray Astrophysics with the Atmospheric Air Cherenkov Telescope Technique

    NASA Astrophysics Data System (ADS)

    Mirzoyan, Razmik

    2013-06-01

    In the recent two decades the ground-based technique of imaging atmosphericescopes has established itself as a powerful new discipline in science. As of today some ˜ 150 sources of gamma rays of very different types, of both galactic and extragalactic origin, have been discovered due to this technique. The study of these sources is providing clues to many basic questions in astrophysics, astro-particle physics, physics of cosmic rays and cosmology. The current generation of telescopes, despite the young age of the technique, offers a solid performance. The technique is still maturing, leading to the next generation large instrument known under the name Cherenkov Telescope Array. The latter's sensitivity will be an order of magnitude higher than that of the currently best instruments VERITAS, H.E.S.S. and MAGIC. This article is devoted to outlining the milestones in a long history that step-by-step have given shape to this technique and have brought about today's successful source marathon.

  18. A review of 4/pi/ /hacek C/erenkov ring imaging detectors

    SciTech Connect

    Leith, D.W.G.S

    1989-06-01

    The design choices for 4/pi/ ring imaging /hacek C/erenkov counters -- both those of principle and those of practice -- are reviewed. The progress in construction and the performance of the devices being built for DELPHI and SLD are discussed. 13 refs., 22 figs.

  19. Activation of photodynamic therapy in vitro with Cerenkov luminescence generated from Yttrium-90 (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Hartl, Brad A.; Hirschberg, Henry; Marcu, Laura; Cherry, Simon R.

    2016-03-01

    Translation of photodynamic therapy to the clinical setting has primarily been limited to easily accessible and/or superficial diseases where traditional light delivery can be performed noninvasively. Cerenkov luminescence, as generated from medically relevant radionuclides, has been suggested as a means to deliver light to deeper tissues noninvasively in order to overcome this depth limitation. We report on the use of Cerenkov luminescence generated from Yttrium-90 as a means to active the photodynamic therapy process in monolayer tumor cell cultures. The current study investigates the utility of Cerenkov luminescence for activating both the clinically relevant aminolevulinic acid at 1.0 mM and also the more efficient photosensitizer TPPS2a at 1.2 µM. Cells were incubated with aminolevulinic acid for 6 hours prior to radionuclide addition, as well as additional daily treatments for three days. TPPS2a was delivered as a single treatment with an 18 hour incubation time before radionuclide addition. Experiments were completed for both C6 glioma cells and MDA-MB-231 breast tumor cells. Although aminolevulinic acid proved ineffective for generating a therapeutic effect at any activity for either cell line, TPPS2a produced at least a 20% therapeutic effect at activities ranging from 6 to 60 µCi/well for the C6 cell line. Current results demonstrate that it may be possible to generate a therapeutic effect in vivo using Cerenkov luminescence to activate the photodynamic therapy process with clinically relevant photosensitizers.

  20. Activating Photodynamic Therapy in vitro with Cerenkov Radiation Generated from Yttrium-90

    PubMed Central

    Hartl, Brad A.; Hirschberg, Henry; Marcu, Laura; Cherry, Simon R.

    2017-01-01

    The translation of photodynamic therapy (PDT) to the clinical setting has primarily been limited to easily accessible and/or superficial diseases, for which traditional light delivery can be performed noninvasively. Cerenkov radiation, as generated from medically relevant radionuclides, has been suggested as a means to deliver light to deeper tissues noninvasively to overcome this depth limitation. This article investigates the utility of Cerenkov radiation, as generated from the radionuclide yttrium-90, for activating the PDT process using clinically approved aminolevulinic acid at 1.0 mm and also the more efficient porphyrin-based photosensitizer mesotetraphenylporphine with two sulfonate groups on adjacent phenyl rings (TPPS2a) at 1.2 μM. Experiments were conducted with monolayer cultured glioma and breast tumor cell lines. Although aminolevulinic acid proved to be ineffective for generating a therapeutic effect at all but the highest activity levels, TPPS2a produced at least a 20% therapeutic effect at activities ranging from 6 to 60 μCi/well for the C6 glioma cell line. Importantly, these results demonstrate for the first time, to our knowledge, that Cerenkov radiation generated from a radionuclide can be used to activate PDT using clinically relevant photosensitizers. These results therefore provide evidence that it may be possible to generate a phototherapeutic effect in vivo using Cerenkov radiation and clinically relevant photosensitizers. PMID:27481495

  1. Visual phenomena induced by relativistic carbon ions with and without Cerenkov radiation

    NASA Technical Reports Server (NTRS)

    Mcnulty, P. J.; Pease, V. P.; Bond, V. P.

    1978-01-01

    Exposing the human eye to individual carbon ions moving at relativistic speeds results in visual phenomena that include point flashes, streaks, and larger diffuse flashes. The diffuse flashes have previously been observed by astronauts in space but not in laboratory experiments with particles of high atomic number and energy. They are observed only when the nucleus moves fast enough to generate Cerenkov radiation.

  2. In vivo Cerenkov luminescence imaging: a new tool for molecular imaging.

    PubMed

    Mitchell, Gregory S; Gill, Ruby K; Boucher, David L; Li, Changqing; Cherry, Simon R

    2011-11-28

    Cerenkov radiation is a phenomenon where optical photons are emitted when a charged particle moves faster than the speed of light for the medium in which it travels. Recently, we and others have discovered that measurable visible light due to the Cerenkov effect is produced in vivo following the administration of β-emitting radionuclides to small animals. Furthermore, the amounts of injected activity required to produce a detectable signal are consistent with small-animal molecular imaging applications. This surprising observation has led to the development of a new hybrid molecular imaging modality known as Cerenkov luminescence imaging (CLI), which allows the spatial distribution of biomolecules labelled with β-emitting radionuclides to be imaged in vivo using sensitive charge-coupled device cameras. We review the physics of Cerenkov radiation as it relates to molecular imaging, present simulation results for light intensity and spatial distribution, and show an example of CLI in a mouse cancer model. CLI allows many common radiotracers to be imaged in widely available in vivo optical imaging systems, and, more importantly, provides a pathway for directly imaging β(-)-emitting radionuclides that are being developed for therapeutic applications in cancer and that are not readily imaged by existing methods.

  3. Cerenkov counter design for a high energy, high intensity secondary beam

    SciTech Connect

    Borcherding, F.O.

    1986-04-01

    A cerenkov counter design is given for operation in a 500 GeV/c secondary beam with 10/sup 9/ to 10/sup 11/ particles per 1 millisecond spill. The design allows the fractions of pions, kaons and protons to be determined. In particular the fraction of kaons should be measured with a relative accuracy of a few percent.

  4. Dealing with Cerenkov radiation generated in organic scintillator dosimeters by bremsstrahlung beams

    NASA Astrophysics Data System (ADS)

    Clift, M. A.; Sutton, R. A.; Webb, D. V.

    2000-05-01

    An organic scintillator detector system has been developed for radiotherapy bremsstrahlung dosimetry. The scintillators are connected to photodiodes by light pipes as the photodiodes must be removed and shielded from the incident radiation. The photodiodes see visible and near-visible light emissions from the scintillator as well as Cerenkov and fluorescence radiation that has been generated and trapped in the scintillator and light pipe. The Cerenkov and fluorescence radiation limits the accuracy of the dosimeter. This work examines a range of methods for diminishing the signal contribution of Cerenkov and fluorescence radiation while optimizing the scintillator signal. Three methods of achieving these goals have been used. They are: reflective coatings on the scintillator, long-wavelength-emitting scintillators used in conjunction with the photodiode, and absorptive filters placed between the light guide and photodiode. The contribution of the Cerenkov radiation to the light seen by the photodiode has been modelled and the model predictions have been tested using bremsstrahlung beams of peak energy between 13 and 20 MV, showing agreement with measurement.

  5. New catadioptric telescope

    NASA Astrophysics Data System (ADS)

    Richter, J. L.

    1981-01-01

    The Acme telescope is a compound telescope that resembles the familiar Cassegrain type except that the main mirror is spherical and the secondary is an achromatic doublet mangin mirror. Three 6-in. aperture f/15 telescope designs are described. With a cemented, all spherical surface achromangin mirror, there is a small amount of coma which can be eliminated by redesigning with an air space between the crown and flint elements of the achromangin mirror, or by cementing them with one of the concave external surfaces of achromangin figured to an hyperboloid. In the examples, the spherical aberration is nil and the chromatic residual is roughly half that of an achromatic objective of the same speed, aperture, and glass types. Readily available crown and flint glasses such as Schott BK-7 and F-2 are entirely satisfactory for the achromangin mirror. Also considered are two examples of Acme-like telescopes with paraboloidal instead of spherical main mirrors.

  6. Webb Telescope Backplane Arrives at NASA Goddard Space Flight Center

    NASA Video Gallery

    Webb Telescope's Backplane arrived at Joint Base Andrews on Monday, August 24, 2015 aboard a U.S. Air Force C-5 cargo plane. The Backplane, inside the Space Telescope Transporter for Air Road and S...

  7. Flying high-altitude balloon-borne telescopes 50 years ago

    NASA Astrophysics Data System (ADS)

    Fazio, Giovanni G.

    Based on theoretical predictions of cosmic gamma-ray fluxes by P. Morrison (1958) and M. Savedoff (1959), we started, at the University of Rochester, a program in high-energy gammaray astronomy to search for these sources using high-altitude balloon-borne telescopes. The first flight occurred in 1959 from Sioux Falls, SD, using scintillator/Cerenkov detectors. In 1962 I initiated a gamma-ray astronomy program at the Smithsonian Astrophysical Observatory (SAO) using vidicon spark chambers. Later Henry Helmken (SAO) developed a program in low-energy gamma-ray astronomy based on a gas Cerenkov detector. During the 1960's more flights followed from San Angelo, TX; Holloman AFB, NM; Hyderabad, India, and finally, Palestine, TX. All of these flights just produced upper limits to the cosmic gamma-ray flux. We also entered a collaboration with the Cornell Group (K. Greisen) to fly a large gas-Cerenkov telescope to search for ˜ 100 MeV gamma-rays. In the early 1970's, using this telescope, gammarays from the Crab Nebula pulsar were detected (McBreen et al. 1973). It soon became evident that gamma-ray astronomy, to be successful, had to be performed from space telescopes. In 1970, somewhat frustrated, I changed fields and started at SAO/Harvard the construction of a 1-meter balloon-borne telescope for far-infrared astronomy. This was a collaborative program with the University of Arizona (F. Low). This program was extremely successful, resulting in 19 flights over 20 years, and produced the first far-infrared high-resolution maps of many new galactic regions and detection of solar system sources. Experience gained from these programs later led to the development and flight of space gamma-ray and infrared telescopes and many of the participants were, and some still are, active in numerous space programs.

  8. Telescope Equipment

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Renaissance Telescope for high resolution and visual astronomy has five 82-degree Field Tele-Vue Nagler Eyepieces, some of the accessories that contribute to high image quality. Telescopes and eyepieces are representative of a family of optical equipment manufactured by Tele-Vue Optics, Inc.

  9. Air

    MedlinePlus

    ... do to protect yourself from dirty air . Indoor air pollution and outdoor air pollution Air can be polluted indoors and it can ... this chart to see what things cause indoor air pollution and what things cause outdoor air pollution! Indoor ...

  10. Thermal conditioning of the AEOS Telescope

    NASA Astrophysics Data System (ADS)

    Roberts, Lewis C., Jr.; Figgis, Peter D.

    2003-02-01

    The AEOS telescope facility was designed for high angular resolution imagery. Part of that design is the inclusion of several air handling systems to maximize dome seeing. Four air conditioning units chill the telescope and dome air to the predicted nighttime temperature. There is a mirror purge system, which prevents moisture from condensing on the mirror by blowing desiccated air into the mirror cell. A laminar air system counteracts the seeing degradation effects of a warm mirror by blowing air across the face of the primary. An hour before sunset the dome is partially opened and outside air is pulled through the telescope truss structure in an effort to remove any thermal differences caused by incorrect cooling. Finally a fan pulls air through the coude' tube in order to remove rising air cells. We present details of each system and the beginnings of our experiments to determine their efficacy. Finally, lessons learned from the systems on the AEOS telescope are presented.

  11. Measurement of Cerenkov radiation induced by the gamma-rays of Co-60 therapy units using wavelength shifting fiber.

    PubMed

    Jang, Kyoung Won; Shin, Sang Hun; Kim, Seon Geun; Kim, Jae Seok; Yoo, Wook Jae; Ji, Young Hoon; Lee, Bongsoo

    2014-04-21

    In this study, a wavelength shifting fiber that shifts ultra-violet and blue light to green light was employed as a sensor probe of a fiber-optic Cerenkov radiation sensor. In order to characterize Cerenkov radiation generated in the developed wavelength shifting fiber and a plastic optical fiber, spectra and intensities of Cerenkov radiation were measured with a spectrometer. The spectral peaks of light outputs from the wavelength shifting fiber and the plastic optical fiber were measured at wavelengths of 500 and 510 nm, respectively, and the intensity of transmitted light output of the wavelength shifting fiber was 22.2 times higher than that of the plastic optical fiber. Also, electron fluxes and total energy depositions of gamma-ray beams generated from a Co-60 therapy unit were calculated according to water depths using the Monte Carlo N-particle transport code. The relationship between the fluxes of electrons over the Cerenkov threshold energy and the energy depositions of gamma-ray beams from the Co-60 unit is a near-identity function. Finally, percentage depth doses for the gamma-ray beams were obtained using the fiber-optic Cerenkov radiation sensor, and the results were compared with those obtained by an ionization chamber. The average dose difference between the results of the fiber-optic Cerenkov radiation sensor and those of the ionization chamber was about 2.09%.

  12. Elimination of Cerenkov interference in a fibre-optic-coupled radiation dosemeter.

    PubMed

    Justus, Brian L; Falkenstein, Paul; Huston, Alan L; Plazas, Maria C; Ning, Holly; Miller, Robert W

    2006-01-01

    An optical fibre point dosemeter based on the gated detection of the luminescence from a Cu(1+)-doped fused quartz detector effectively eliminated errors due to Cerenkov radiation and native fibre fluorescence. The gated optical fibre dosemeter overcomes serious problems faced by scintillation and optically stimulated luminescence approaches to optical fibre point dosimetry. The dosemeter was tested using an external beam radiotherapy machine that provided pulses of 6 MV X rays. Gated detection was used to discriminate the signal collected during the radiation pulses, which included contributions from Cerenkov radiation and native fibre fluorescence, from the signal collected between the radiation pulses, which contained only the long-lived luminescence from the Cu(1+)-doped fused quartz detector. Gated detection of the luminescence provided accurate, real-time dose measurements that were linear with absorbed dose, independent of dose rate and that were accurate for all field sizes studied.

  13. Frequency of light-flashes induced by Cerenkov radiation from heavy cosmic-ray nuclei

    NASA Technical Reports Server (NTRS)

    Madey, R.; Mcnulty, P. J.

    1972-01-01

    The expected frequency was calculated for light flashes induced in the dark-adapted eye by Cerenkov radiation from the flux of heavy nuclei that exists in space beyond the geomagnetic field. The expected frequency of light flashes depends on the threshold number of photons that must be absorbed in a rod cluster. The results of the calculation are presented as a curve of the mean frequency of light flashes versus the threshold number of absorbed photons. The results are not sensitive to variations in the path length from 5 to 15 grams per square centimeter of water-equivalent before the nucleus reaches the retina. Calculations were based on the fluxes and energy spectra of galactic cosmic ray nuclei of helium to iron, measured at a time of minimum solar modulation. The expected light flash frequencies induced by Cerenkov radiation are consistent with the frequencies reported by the astronauts on Apollo missions 11 through 14.

  14. Quantitative assessment of Cerenkov luminescence for radioguided brain tumor resection surgery.

    PubMed

    Klein, Justin S; Mitchell, Gregory; Cherry, Simon

    2017-03-13

    Cerenkov luminescence imaging (CLI) is a developing imaging modality that detects radiolabeled molecules via visible light emitted during the radioactive decay process. We used a Monte Carlo based computer simulation to quantitatively investigate CLI compared to direct detection of the ionizing radiation itself as an intraoperative imaging tool for assessment of brain tumor margins. Our brain tumor model consisted of a 1 mm spherical tumor remnant embedded up to 5 mm in depth below the surface of normal brain tissue. Tumor to background contrast ranging from 2:1 to 10:1 were considered. We quantified all decay signals (e+/-, gamma photon, Cerenkov photons) reaching the brain volume surface. CLI proved to be the most sensitive method for detecting the tumor volume in both imaging and non-imaging strategies as assessed by contrast-to-noise ratio and by receiver operating characteristic output of a channelized Hotelling observer.

  15. SNAP Telescope

    NASA Astrophysics Data System (ADS)

    Lampton, Michael L.; Akerlof, Carl W.; Aldering, Greg; Amanullah, R.; Astier, Pierre; Barrelet, E.; Bebek, Christopher; Bergstrom, Lars; Bercovitz, John; Bernstein, G.; Bester, Manfred; Bonissent, Alain; Bower, C. R.; Carithers, William C., Jr.; Commins, Eugene D.; Day, C.; Deustua, Susana E.; DiGennaro, Richard S.; Ealet, Anne; Ellis, Richard S.; Eriksson, Mikael; Fruchter, Andrew; Genat, Jean-Francois; Goldhaber, Gerson; Goobar, Ariel; Groom, Donald E.; Harris, Stewart E.; Harvey, Peter R.; Heetderks, Henry D.; Holland, Steven E.; Huterer, Dragan; Karcher, Armin; Kim, Alex G.; Kolbe, William F.; Krieger, B.; Lafever, R.; Lamoureux, J.; Levi, Michael E.; Levin, Daniel S.; Linder, Eric V.; Loken, Stewart C.; Malina, Roger; Massey, R.; McKay, Timothy; McKee, Shawn P.; Miquel, Ramon; Mortsell, E.; Mostek, N.; Mufson, Stuart; Musser, J. A.; Nugent, Peter E.; Oluseyi, Hakeem M.; Pain, Reynald; Palaio, Nicholas P.; Pankow, David H.; Perlmutter, Saul; Pratt, R.; Prieto, Eric; Refregier, Alexandre; Rhodes, J.; Robinson, Kem E.; Roe, N.; Sholl, Michael; Schubnell, Michael S.; Smadja, G.; Smoot, George F.; Spadafora, A.; Tarle, Gregory; Tomasch, Andrew D.; von der Lippe, H.; Vincent, R.; Walder, J.-P.; Wang, Guobin

    2002-12-01

    The SuperNova/Acceleration Probe (SNAP) mission will require a two-meter class telescope delivering diffraction limited images spanning a one degree field in the visible and near infrared wavelength regime. This requirement, equivalent to nearly one billion pixel resolution, places stringent demands on its optical system in terms of field flatness, image quality, and freedom from chromatic aberration. We discuss the advantages of annular-field three-mirror anastigmat (TMA) telescopes for applications such as SNAP, and describe the features of the specific optical configuration that we have baselined for the SNAP mission. We discuss the mechanical design and choice of materials for the telescope. Then we present detailed ray traces and diffraction calculations for our baseline optical design. We briefly discuss stray light and tolerance issues, and present a preliminary wavefront error budget for the SNAP Telescope. We conclude by describing some of tasks to be carried out during the upcoming SNAP research and development phase.

  16. SNAP telescope

    SciTech Connect

    Lampton, Michael L.; Akerlof, C.W.; Aldering, G.; Amanullah, R.; Astier, P.; Barrelet, E.; Bebek, C.; Bergstrom, L.; Bercovitz, J.; Bernstein, G.; Bester, M.; Bonissent, A.; Bower, C.; Carithers Jr., W.C.; Commins, E.D.; Day, C.; Deustua, S.E.; DiGennaro, R.; Ealet, A.; Ellis,R.S.; Eriksson, M.; Fruchter, A.; Genat, J.-F.; Goldhaber, G.; Goobar,A.; Groom, D.; Harris, S.E.; Harvey, P.R.; Heetderks, H.D.; Holland,S.E.; Huterer, D.; Karcher, A.; Kim, A.G.; Kolbe, W.; Krieger, B.; Lafever, R.; Lamoureux, J.; Levi, M.E.; Levin, D.S.; Linder, E.V.; Loken,S.C.; Malina, R.; Massey, R.; McKay, T.; McKee, S.P.; Miquel, R.; Mortsell, E.; Mostek, N.; Mufson, S.; Musser, J.; Nugent, P.; Oluseyi,H.; Pain, R.; Palaio, N.; Pankow, D.; Perlmutter, S.; Pratt, R.; Prieto,E.; Refregier, A.; Rhodes, J.; Robinson, K.; Roe, N.; Sholl, M.; Schubnell, M.; Smadja, G.; Smoot, G.; Spadafora, A.; Tarle, G.; Tomasch,A.; von der Lippe, H.; Vincent, R.; Walder, J.-P.; Wang, G.; Wang, G.

    2002-07-29

    The SuperNova/Acceleration Probe (SNAP) mission will require a two-meter class telescope delivering diffraction limited images spanning a one degree field in the visible and near infrared wavelength regime. This requirement, equivalent to nearly one billion pixel resolution, places stringent demands on its optical system in terms of field flatness, image quality, and freedom from chromatic aberration. We discuss the advantages of annular-field three-mirror anastigmat (TMA) telescopes for applications such as SNAP, and describe the features of the specific optical configuration that we have baselined for the SNAP mission. We discuss the mechanical design and choice of materials for the telescope. Then we present detailed ray traces and diffraction calculations for our baseline optical design. We briefly discuss stray light and tolerance issues, and present a preliminary wavefront error budget for the SNAP Telescope. We conclude by describing some of tasks to be carried out during the upcoming SNAP research and development phase.

  17. Teaching Telescopes

    ERIC Educational Resources Information Center

    Reid, John S.

    1974-01-01

    Discusses experience of teaching optical experiments with emphasis upon the student's design and construction of refracting and reflecting telescopes. Concludes that the student's interest and acquired knowledge are greatly enhanced through the use of realistic experiments. (CC)

  18. Cerenkov luminescence endoscopy: Improved molecular sensitivity with β--emitting radiotracers

    DOE PAGES

    Carpenter, Colin M.; Ma, Xiaowei; Liu, Hongguang; ...

    2014-10-09

    Cerenkov luminescence endoscopy (CLE) is an optical technique that captures the Cerenkov photons emitted from highly energetic moving charged particles (β+ or β$-$) and can be used to monitor the distribution of many clinically available radioactive probes. A main limitation of CLE is its limited sensitivity to small concentrations of radiotracer, especially when used with a light guide. We investigated the improvement in the sensitivity of CLE brought about by using a β$-$ radiotracer that improved Cerenkov signal due to both higher β-particle energy and lower γ noise in the imaging optics because of the lack of positron annihilation. Here,more » the signal-to-noise ratio (SNR) of 90Y was compared with that of 18F in both phantoms and small-animal tumor models. Sensitivity and noise characteristics were demonstrated using vials of activity both at the surface and beneath 1 cm of tissue. Rodent U87MG glioma xenograft models were imaged with radiotracers bound to arginine-glycine-aspartate (RGD) peptides to determine the SNR. As a result, γ noise from 18F was demonstrated by both an observed blurring across the field of view and a more pronounced fall-off with distance. A decreased γ background and increased energy of the β particles resulted in a 207-fold improvement in the sensitivity of 90Y compared with 18F in phantoms. 90Y-bound RGD peptide produced a higher tumor-to-background SNR than 18F in a mouse model. In conclusion, the use of 90Y for Cerenkov endoscopic imaging enabled superior results compared with an 18F radiotracer.« less

  19. Cerenkov luminescence endoscopy: Improved molecular sensitivity with β--emitting radiotracers

    SciTech Connect

    Carpenter, Colin M.; Ma, Xiaowei; Liu, Hongguang; Sun, Conroy; Pratx, Guillem; Wang, Jing; Gambhir, Sanjiv S.; Xing, Lei; Cheng, Zhen

    2014-10-09

    Cerenkov luminescence endoscopy (CLE) is an optical technique that captures the Cerenkov photons emitted from highly energetic moving charged particles (β+ or β$-$) and can be used to monitor the distribution of many clinically available radioactive probes. A main limitation of CLE is its limited sensitivity to small concentrations of radiotracer, especially when used with a light guide. We investigated the improvement in the sensitivity of CLE brought about by using a β$-$ radiotracer that improved Cerenkov signal due to both higher β-particle energy and lower γ noise in the imaging optics because of the lack of positron annihilation. Here, the signal-to-noise ratio (SNR) of 90Y was compared with that of 18F in both phantoms and small-animal tumor models. Sensitivity and noise characteristics were demonstrated using vials of activity both at the surface and beneath 1 cm of tissue. Rodent U87MG glioma xenograft models were imaged with radiotracers bound to arginine-glycine-aspartate (RGD) peptides to determine the SNR. As a result, γ noise from 18F was demonstrated by both an observed blurring across the field of view and a more pronounced fall-off with distance. A decreased γ background and increased energy of the β particles resulted in a 207-fold improvement in the sensitivity of 90Y compared with 18F in phantoms. 90Y-bound RGD peptide produced a higher tumor-to-background SNR than 18F in a mouse model. In conclusion, the use of 90Y for Cerenkov endoscopic imaging enabled superior results compared with an 18F radiotracer.

  20. Experimental Evidence for Cerenkov Emission of Whistler Waves by Electron Holes Associated with Magnetic Reconnection

    NASA Astrophysics Data System (ADS)

    Eastwood, J. P.; Goldman, M. V.; Zhang, X.; Hietala, H.; Krupar, V.; Newman, D. L.; Angelopoulos, V.; Lapenta, G.

    2015-12-01

    Whistler waves are a ubiquitous plasma phenomenon, observed in a variety of space and laboratory plasma environments. They play a key role in many important and diverse processes, such as particle acceleration in the radiation belts and auroral acceleration region, the dissipation of plasma turbulence at small scales below the inertial range, collisionless shock physics, and magnetic reconnection. In reconnection they may modify the reconnection rate and also whistler physics is crucial to enabling fast reconnection in the Hall reconnection model. Consequently, understanding how whistler waves are generated and how they subsequently interact with the plasma is a problem of wide importance and application. It is well known that whistlers can arise as a result of kinetic instabilities, which grow exponentially from noise as a consequence of unstable electron distributions, for example temperature anisotropy. This is used ubiquitously to predict where and when whistler waves are likely to exist and therefore be of importance in many plasma phenomena. Recently it has been demonstrated theoretically and via computer simulations that whistler waves may also arise via Cerenkov emission from electron hole quasi-particles [Goldman et al., PRL, 2014]. Such wave emission can arise even when the temperature anisotropy leads to damping; in this case the system is analogous to a damped forced oscillator. Here we present novel experimental analysis from THEMIS showing for the first time evidence consistent with the generation of whistlers via Cerenkov emission during magnetotail reconnection. By considering the electromagnetic properties of the electron holes, the amplitude, phase speed and frequency of the associated whistlers, and also the available sub-spin observations of the electron distribution function, we find that the data are best explained by the Cerenkov emission theory rather than by kinetic instabilities due to the electron temperature anisotropy. Whilst the

  1. Cerenkov Luminescence Endoscopy: Improved Molecular Sensitivity with β−-Emitting Radiotracers

    PubMed Central

    Carpenter, Colin M.; Ma, Xiaowei; Liu, Hongguang; Sun, Conroy; Pratx, Guillem; Wang, Jing; Gambhir, Sanjiv S.; Xing, Lei; Cheng, Zhen

    2015-01-01

    Cerenkov luminescence endoscopy (CLE) is an optical technique that captures the Cerenkov photons emitted from highly energetic moving charged particles (β+ or β−) and can be used to monitor the distribution of many clinically available radioactive probes. A main limitation of CLE is its limited sensitivity to small concentrations of radiotracer, especially when used with a light guide. We investigated the improvement in the sensitivity of CLE brought about by using a β− radiotracer that improved Cerenkov signal due to both higher β-particle energy and lower γ noise in the imaging optics because of the lack of positron annihilation. Methods The signal-to-noise ratio (SNR) of 90Y was compared with that of 18F in both phantoms and small-animal tumor models. Sensitivity and noise characteristics were demonstrated using vials of activity both at the surface and beneath 1 cm of tissue. Rodent U87MG glioma xenograft models were imaged with radiotracers bound to arginine-glycine-aspartate (RGD) peptides to determine the SNR. Results γ noise from 18F was demonstrated by both an observed blurring across the field of view and a more pronounced fall-off with distance. A decreased γ background and increased energy of the β particles resulted in a 207-fold improvement in the sensitivity of 90Y compared with 18F in phantoms. 90Y-bound RGD peptide produced a higher tumor-to-background SNR than 18F in a mouse model. Conclusion The use of 90Y for Cerenkov endoscopic imaging enabled superior results compared with an 18F radiotracer. PMID:25300598

  2. Cerenkov Luminescence Imaging as a Modality to Evaluate Antibody-Based PET Radiotracers.

    PubMed

    D'Souza, Jimson W; Hensley, Harvey; Doss, Mohan; Beigarten, Charles; Torgov, Michael; Olafsen, Tove; Yu, Jian Q; Robinson, Matthew K

    2017-01-01

    Antibodies, and engineered antibody fragments, labeled with radioisotopes are being developed as radiotracers for the detection and phenotyping of diseases such as cancer. The development of antibody-based radiotracers requires extensive characterization of their in vitro and in vivo properties, including their ability to target tumors in an antigen-selective manner. In this study, we investigated the use of Cerenkov luminescence imaging (CLI) as compared with PET as a modality for evaluating the in vivo behavior of antibody-based radiotracers.

  3. Effect of beam self-rotation on a Cerenkov free-electron laser

    SciTech Connect

    Mishra, G.

    1989-04-15

    At large beam currents, the beam space charge produces a radial electric field causing E x B rotation of the beam. As the beam travels through a partially dielectric loaded waveguide, it emits coherent Cerenkov radiation at frequencies ..omega.. = ..beta..v/sub b/+l(..omega../sub ..cap alpha..//..gamma../sub 0/), where l is the azimuthal mode number, ..omega../sub ..cap alpha../ is the angular frequency of rotation, and ..beta.. is the propagation constant.

  4. Space Telescopes

    DTIC Science & Technology

    2010-01-01

    the Kirkpatrick–Baez type systems and the focussing colli- mator or ‘ lobster -eye’ systems. 1http://henke.lbl.gov/optical constants/ 176 9. Space...mirror requires a longer telescope. Focussing collimator or ‘ lobster -eye’ telescopes The Wolter and the Kirkpatrick–Baez systems have in common a...9.13: Flat-mirror two-dimensional focussing collimator or detached lobster - eye configuration (Schmidt 1975). within one tube but from adjacent walls a

  5. Ultra low fluence rate photodynamic therapy: simulation of light emitted by the Cerenkov effect

    NASA Astrophysics Data System (ADS)

    Gonzales, Jonathan; Wang, Fred; Zamora, Genesis; Trinidad, Anthony; Marcu, Laura; Cherry, Simon; Hirschberg, Henry

    2014-03-01

    PDT has been shown to be most effective at low fluence rates. Many radionuclides used for both diagnostic and therapeutic purposes produce measurable amounts of visible radiation when they decay via the Cerenkov effect which occurs when a charged particle travels faster in a dielectric medium than the speed of light in that medium. Cerenkov radiation from radiopharmaceuticals could serve as a source of extended duration, low level "internal" light, to mediate PDT, with the ultimate goals of overcoming some its current limitations. Using laser light, we are exploring the effects of fluence rates that could be generated by Cerenkov radiation on PDT efficacy. ALA or TPPS2a mediated PDT of rat gliomas monolayers or multicell spheroids ( F98, C6) was performed with 410 nm laser light exposure over an extended period of 24-96hrs. Photosensitizers were delivered either as a bolus or continuously with light exposure. At fluence rate of 20μW/cm2 effective PDT was obtained as measured by decrease in cell viability or inhibition of spheroid growth. PDT is effective at ultra low fluence rates if given over long time periods. No lower threshold has been ascertained. Since the half-life of 90Y, a radionuclide with a high Cherenkov yield is 64 hrs it is a good candidate to supply sufficient light activation for PDT. The combination of radionuclide and photodynamic therapies could improve the effectiveness of cancer treatment by exploiting synergies between these two modalities.

  6. High resolution Cerenkov and range detectors for balloon-borne cosmic-ray experiment

    NASA Technical Reports Server (NTRS)

    Ahlen, S. P.; Cartwright, B. G.; Tarle, G.

    1975-01-01

    A combination of an active Cerenkov detector and passive range detectors is proposed for the high resolution measurement of isotopic composition in the neighborhood of iron in the galactic cosmic rays. A large area (4,300 sq cm) Cerenkov counter and passive range detectors were tested. Tests with heavy ions (2.1 GeV/amu C-12, 289 MeV/amu Ar-40, and 594 MeV/amu Ne-20) revealed the spatial uniformity of response of the Cerenkov counter to be better than 1% peak-to-peak. Light collection efficiency is independent of projectile energy and incidence angle to within at least 0.5%. Passive Lexan track recorders to measure range in the presence of the nuclear interaction background which results from stopping particles through 0.9 interaction lengths of matter were also tested. It was found that nuclear interactions produce an effective range straggling distribution only approximately 75% wider than that expected from range straggling alone. The combination of these tested techniques makes possible high mass resolution in the neighborhood of iron.

  7. SU-E-J-17: A Study of Accelerator-Induced Cerenkov Radiation as a Beam Diagnostic and Dosimetry Tool

    SciTech Connect

    Bateman, F; Tosh, R

    2014-06-01

    Purpose: To investigate accelerator-induced Cerenkov radiation imaging as a possible beam diagnostic and medical dosimetry tool. Methods: Cerenkov emission produced by clinical accelerator beams in a water phantom was imaged using a camera system comprised of a high-sensitivity thermoelectrically-cooled CCD camera coupled to a large aperture (f/0.75) objective lens with 16:1 magnification. This large format lens allows a significant amount of the available Cerenkov light to be collected and focused onto the CCD camera to form the image. Preliminary images, obtained with 6 MV photon beams, used an unshielded camera mounted horizontally with the beam normal to the water surface, and confirmed the detection of Cerenkov radiation. Several improvements were subsequently made including the addition of radiation shielding around the camera, and altering of the beam and camera angles to give a more favorable geometry for Cerenkov light collection. A detailed study was then undertaken over a range of electron and photon beam energies and dose rates to investigate the possibility of using this technique for beam diagnostics and dosimetry. Results: A series of images were obtained at a fixed dose rate over a range of electron energies from 6 to 20 MeV. The location of maximum intensity was found to vary linearly with the energy of the beam. A linear relationship was also found between the light observed from a fixed point on the central axis and the dose rate for both photon and electron beams. Conclusion: We have found that the analysis of images of beam-induced Cerenkov light in a water phantom has potential for use as a beam diagnostic and medical dosimetry tool. Our future goals include the calibration of the light output in terms of radiation dose and development of a tomographic system for 3D Cerenkov imaging in water phantoms and other media.

  8. The detection of high charge cosmic ray nuclei. [by balloon-borne electronic particle telescope

    NASA Technical Reports Server (NTRS)

    Scarlett, W. R.; Freier, P. S.; Waddington, C. J.

    1975-01-01

    A large-area, light-weight electronic particle telescope was flown on a high altitude balloon in the summer of 1974 to study the heavy nuclei in the cosmic radiation. This telescope consisted of a double Cerenkov-double scintillator array composed of four 1.22 m diameter disk radiators mounted in light diffusion boxes, each looked at by multiple photomultipliers. The impact point of each particle on the scintillation radiators was determined by studying the relative signals observed by three equally spaced peripheral photomultipliers and one mounted at the center of the diffusion boxes. This telescope was flown in a configuration having a geometric factor of 0.45 sq m sr and observed some 5 x 10 to the 4 nuclei with Z exceeding 14 in a 11 hr exposure. The response and sensitivity of this telescope are discussed in detail.

  9. Telescopic hindsight

    NASA Astrophysics Data System (ADS)

    Cox, Laurence

    2014-08-01

    In reply to the physicsworld.com blog post "Cosmic blunders that have held back science" (2 June, http://ow.ly/xwC7C), about an essay by the astronomer Avi Loeb in which he criticized, among others, his Harvard University predecessor Edward Pickering, who claimed in 1909 that telescopes had reached their optimal size.

  10. Infrared telescope

    NASA Technical Reports Server (NTRS)

    Karr, G. R.; Hendricks, J. B.

    1985-01-01

    The development of the Infrared Telescope for Spacelab 2 is discussed. The design, development, and testing required to interface a stationary superfluid helium dewar with a scanning cryostate capable of operating in the zero-g environment in the space shuttle bay is described.

  11. Selecting Your First Telescope.

    ERIC Educational Resources Information Center

    Harrington, Sherwood

    1982-01-01

    Designed for first-time telescope purchasers, provides information on how a telescope works; major telescope types (refractors, reflectors, compound telescopes); tripod, pier, altazimuth, and equatorial mounts; selecting a telescope; visiting an astronomy club; applications/limitations of telescope use; and tips on buying a telescope. Includes a…

  12. Development of a wavelength-separated type scintillator with optical fiber (SOF) dosimeter to compensate for the Cerenkov radiation effect

    PubMed Central

    Ishikawa, Masayori; Nagase, Naomi; Matsuura, Taeko; Hiratsuka, Junichi; Suzuki, Ryusuke; Miyamoto, Naoki; Sutherland, Kenneth Lee; Fujita, Katsuhisa; Shirato, Hiroki

    2015-01-01

    The scintillator with optical fiber (SOF) dosimeter consists of a miniature scintillator mounted on the tip of an optical fiber. The scintillator of the current SOF dosimeter is a 1-mm diameter hemisphere. For a scintillation dosimeter coupled with an optical fiber, measurement accuracy is influenced by signals due to Cerenkov radiation in the optical fiber. We have implemented a spectral filtering technique for compensating for the Cerenkov radiation effect specifically for our plastic scintillator-based dosimeter, using a wavelength-separated counting method. A dichroic mirror was used for separating input light signals. Individual signal counting was performed for high- and low-wavelength light signals. To confirm the accuracy, measurements with various amounts of Cerenkov radiation were performed by changing the incident direction while keeping the Ir-192 source-to-dosimeter distance constant, resulting in a fluctuation of <5%. Optical fiber bending was also addressed; no bending effect was observed for our wavelength-separated SOF dosimeter. PMID:25618136

  13. Development of a wavelength-separated type scintillator with optical fiber (SOF) dosimeter to compensate for the Cerenkov radiation effect.

    PubMed

    Ishikawa, Masayori; Nagase, Naomi; Matsuura, Taeko; Hiratsuka, Junichi; Suzuki, Ryusuke; Miyamoto, Naoki; Sutherland, Kenneth Lee; Fujita, Katsuhisa; Shirato, Hiroki

    2015-03-01

    The scintillator with optical fiber (SOF) dosimeter consists of a miniature scintillator mounted on the tip of an optical fiber. The scintillator of the current SOF dosimeter is a 1-mm diameter hemisphere. For a scintillation dosimeter coupled with an optical fiber, measurement accuracy is influenced by signals due to Cerenkov radiation in the optical fiber. We have implemented a spectral filtering technique for compensating for the Cerenkov radiation effect specifically for our plastic scintillator-based dosimeter, using a wavelength-separated counting method. A dichroic mirror was used for separating input light signals. Individual signal counting was performed for high- and low-wavelength light signals. To confirm the accuracy, measurements with various amounts of Cerenkov radiation were performed by changing the incident direction while keeping the Ir-192 source-to-dosimeter distance constant, resulting in a fluctuation of <5%. Optical fiber bending was also addressed; no bending effect was observed for our wavelength-separated SOF dosimeter.

  14. Plasma density from Cerenkov radiation, betatron oscillations, and beam steering in a plasma wakefield experiment at 30 GeV

    SciTech Connect

    Catravas, P.; Chattopadhyay, S.; Esarey, E.; Leemans, W.P.; Assmann, R.; Decker, F.-J.; Hogan, M.J.; Iverson, R.; Siemann, R.H.; Walz, D.; Whittum, D.; Blue, B.; Clayton, C.; Joshi, C.; Marsh, K.; Mori, W.B.; Wang, S.; Katsouleas, T.; Lee, S.; Muggli, P.

    2001-01-01

    A method for using Cerenkov radiation near atomic spectral lines to measure plasma source properties for plasma wakefield applications has been discussed and experimentally verified. Because the radiation co-propagates with the electron beam, the radiation samples the source properties exactly along the path of interest with perfect temporal synchronization. Observation wavelengths were chosen with respect to the atomic resonances of the plasma source, where the relative change in the index of refraction strongly affects the Cerenkov cone angle, and permits flexible diagnostic design. The Cerenkov spatial profiles were systematically studied for a Lithium heat pipe oven as a function of oven temperature and observation wavelength. Neutral densities and plasma densities were extracted from the measurements.

  15. The modulation to Cerenkov second-harmonic in a LiTaO3 waveguide with annular poling domain

    NASA Astrophysics Data System (ADS)

    Chen, C. D.; Hu, X. P.

    2016-01-01

    We report the modulated Cerenkov up-conversion in a LiTaO3 waveguide with an annular domain structure. As a result of the continuous rotational symmetry of such a structure, the phase velocity of the nonlinear polarization wave has a wide modulation tolerance. The reciprocal vectors which could be involved in the interaction had a threshold range associated with the waveguide parameters. The experimental results and simulations demonstrated that the radiation intensity had a close relationship with the overlap between the pump and the radiated wave, which could be decreased by non-collinear reciprocal vectors. Our detailed discussions on the Cerenkov frequency-doubling process using such an annular-poling crystal may lay the groundwork for the further study of the modulation of other nonlinear Cerenkov processes.

  16. The Falcon Telescope Network

    NASA Astrophysics Data System (ADS)

    Chun, F.; Tippets, R.; Dearborn, M.; Gresham, K.; Freckleton, R.; Douglas, M.

    2014-09-01

    The Falcon Telescope Network (FTN) is a global network of small aperture telescopes developed by the Center for Space Situational Awareness Research in the Department of Physics at the United States Air Force Academy (USAFA). Consisting of commercially available equipment, the FTN is a collaborative effort between USAFA and other educational institutions ranging from two- and four-year colleges to major research universities. USAFA provides the equipment (e.g. telescope, mount, camera, filter wheel, dome, weather station, computers and storage devices) while the educational partners provide the building and infrastructure to support an observatory. The user base includes USAFA along with K-12 and higher education faculty and students. Since the FTN has a general use purpose, objects of interest include satellites, astronomical research, and STEM support images. The raw imagery, all in the public domain, will be accessible to FTN partners and will be archived at USAFA in the Cadet Space Operations Center. FTN users will be able to submit observational requests via a web interface. The requests will then be prioritized based on the type of user, the object of interest, and a user-defined priority. A network wide schedule will be developed every 24 hours and each FTN site will autonomously execute its portion of the schedule. After an observational request is completed, the FTN user will receive notification of collection and a link to the data. The Falcon Telescope Network is an ambitious endeavor, but demonstrates the cooperation that can be achieved by multiple educational institutions.

  17. The Role of Cerenkov Radiation in the Pressure Balance of Cool Core Clusters of Galaxies

    NASA Astrophysics Data System (ADS)

    Lieu, Richard

    2017-03-01

    Despite the substantial progress made recently in understanding the role of AGN feedback and associated non-thermal effects, the precise mechanism that prevents the core of some clusters of galaxies from collapsing catastrophically by radiative cooling remains unidentified. In this Letter, we demonstrate that the evolution of a cluster's cooling core, in terms of its density, temperature, and magnetic field strength, inevitably enables the plasma electrons there to quickly become Cerenkov loss dominated, with emission at the radio frequency of ≲350 Hz, and with a rate considerably exceeding free–free continuum and line emission. However, the same does not apply to the plasmas at the cluster's outskirts, which lacks such radiation. Owing to its low frequency, the radiation cannot escape, but because over the relevant scale size of a Cerenkov wavelength the energy of an electron in the gas cannot follow the Boltzmann distribution to the requisite precision to ensure reabsorption always occurs faster than stimulated emission, the emitting gas cools before it reheats. This leaves behind the radiation itself, trapped by the overlying reflective plasma, yet providing enough pressure to maintain quasi-hydrostatic equilibrium. The mass condensation then happens by Rayleigh–Taylor instability, at a rate determined by the outermost radius where Cerenkov radiation can occur. In this way, it is possible to estimate the rate at ≈2 M ⊙ year‑1, consistent with observational inference. Thus, the process appears to provide a natural solution to the longstanding problem of “cooling flow” in clusters; at least it offers another line of defense against cooling and collapse should gas heating by AGN feedback be inadequate in some clusters.

  18. Measurement accuracy and Cerenkov removal for high performance, high spatial resolution scintillation dosimetry

    SciTech Connect

    Archambault, Louis; Beddar, A. Sam; Gingras, Luc

    2006-01-15

    With highly conformal radiation therapy techniques such as intensity-modulated radiation therapy, radiosurgery, and tomotherapy becoming more common in clinical practice, the use of these narrow beams requires a higher level of precision in quality assurance and dosimetry. Plastic scintillators with their water equivalence, energy independence, and dose rate linearity have been shown to possess excellent qualities that suit the most complex and demanding radiation therapy treatment plans. The primary disadvantage of plastic scintillators is the presence of Cerenkov radiation generated in the light guide, which results in an undesired stem effect. Several techniques have been proposed to minimize this effect. In this study, we compared three such techniques--background subtraction, simple filtering, and chromatic removal--in terms of reproducibility and dose accuracy as gauges of their ability to remove the Cerenkov stem effect from the dose signal. The dosimeter used in this study comprised a 6-mm{sup 3} plastic scintillating fiber probe, an optical fiber, and a color charge-coupled device camera. The whole system was shown to be linear and the total light collected by the camera was reproducible to within 0.31% for 5-s integration time. Background subtraction and chromatic removal were both found to be suitable for precise dose evaluation, with average absolute dose discrepancies of 0.52% and 0.67%, respectively, from ion chamber values. Background subtraction required two optical fibers, but chromatic removal used only one, thereby preventing possible measurement artifacts when a strong dose gradient was perpendicular to the optical fiber. Our findings showed that a plastic scintillation dosimeter could be made free of the effect of Cerenkov radiation.

  19. Detection of solar cosmic rays by Cerenkov detectors at the Meteor satellites

    NASA Astrophysics Data System (ADS)

    Avdiushin, S. I.; Kulagin, Iu. M.; Nazarova, M. N.; Pereiaslova, N. K.; Petrenko, I. E.

    The general design and performance characteristics of the proton detector based on a Cerenkov counter included in the radiometric equipment of the Meteor satellites for the study of galactic and solar cosmic rays are briefly reviewed. To achieve reliable detection of weak light signals (100-120 photons per 1 cm of the proton path), the detector uses a photomultiplier with a high quantum output and high gain for a minimum dark current. Observations of solar proton events with energies in excess of 600 MeV are summarized.

  20. DETECTORS AND EXPERIMENTAL METHODS: Circulation model for water circulation and purification in a water Cerenkov detector

    NASA Astrophysics Data System (ADS)

    Lu, Hao-Qi; Yang, Chang-Gen; Wang, Ling-Yu; Xu, Ji-Lei; Wang, Rui-Guang; Wang, Zhi-Min; Wang, Yi-Fang

    2009-07-01

    Owing to its low cost and good transparency, highly purified water is widely used as a medium in large water Cerenkov detector experiments. The water circulation and purification system is usually needed to keep the water in good quality. In this work, a practical circulation model is built to describe the variation of the water resistivity in the circulation process and compared with the data obtained from a prototype experiment. The successful test of the model makes it useful in the future design and optimization of the circulation/purification system.

  1. Relativistic astrophysics. [design analysis and performance tests of Cerenkov counters for detection of iron isotopes

    NASA Technical Reports Server (NTRS)

    Price, P. B.

    1976-01-01

    The design, experimental testing, and calibration (error analysis) of a high resolution Cerenkov-scintillation detector is presented. The detector is capable of detecting iron isotopes and heavy ions of cosmic rays, and of performing direct measurements of individual neighboring isotopes at charge resolution 26. It utilizes Lexan (trademark) sheets, and has been used in flight packages of balloons and on the Skylab. The detector will be able to provide more information on violet astrophysical processes, such as thermonuclear reactions on neutron stars. Ground support and display equipment which are to be used in conjunction with the detector are also discussed.

  2. Three dimensional nonlinear analysis of a single-grating rectangular waveguide Cerenkov maser

    SciTech Connect

    Xie, Wenqiu; Wang, Zi-Cheng; Luo, Jirun; Zhao, Ding

    2015-04-15

    A three dimensional (3-D) nonlinear model for illustrating the beam-wave interaction in a single-grating rectangular waveguide sheet-beam Cerenkov maser is presented. The dynamical equations and the equations of motion are solved self-consistently to predict the device performance. Space-charge effects and Ohmic losses are considered in the model. A 1.03 THz backward wave oscillator and a 0.65 THz traveling wave tube are discussed as two illustrative examples.

  3. Survey of candidate gamma-ray sources at TeV energies using a high-resolution Cerenkov imaging system - 1988-1991

    NASA Technical Reports Server (NTRS)

    Reynolds, P. T.; Akerlof, C. W.; Cawley, M. F.; Chantell, M.; Fegan, D. J.; Hillas, A. M.; Lamb, R. C.; Lang, M. J.; Lawrence, M. A.; Lewis, D. A.

    1993-01-01

    The steady TeV gamma-ray emission from the Crab Nebula has been used to optimize the sensitivity of the Whipple Observatory atmospheric Cerenkov imaging telescope. Using this method, which is of order 20 times more sensitive than the standard method using a simple non-imaging detector, it is possible to detect the Crab Nebula at a significance level in excess of 6 standard deviations (6 sigma) in under 1 hr on source (with a corresponding time observing a background comparison region); a source one-tenth the strength of the Crab Nebula can be detected at the 4 sigma level after 40 hr on the source (and 40 hr on a background region). A variety of sources have been monitored using this technique over the period 1988-1991, but none were detected apart from the Crab Nebula. Upper limits are presented which in many instances are a factor of 10 below the flux of the Crab Nebula. These upper limits assume steady emission from the source and cannot rule out sporadic gamma-ray emission with short duty cycles.

  4. A simple model for deep tissue attenuation correction and large organ analysis of Cerenkov luminescence imaging

    NASA Astrophysics Data System (ADS)

    Habte, Frezghi; Natarajan, Arutselvan; Paik, David S.; Gambhir, Sanjiv S.

    2014-03-01

    Cerenkov luminescence imaging (CLI) is an emerging cost effective modality that uses conventional small animal optical imaging systems and clinically available radionuclide probes for light emission. CLI has shown good correlation with PET for organs of high uptake such as kidney, spleen, thymus and subcutaneous tumors in mouse models. However, CLI has limitations for deep tissue quantitative imaging since the blue-weighted spectral characteristics of Cerenkov radiation attenuates highly by mammalian tissue. Large organs such as the liver have also shown higher signal due to the contribution of emission of light from a greater thickness of tissue. In this study, we developed a simple model that estimates the effective tissue attenuation coefficient in order to correct the CLI signal intensity with a priori estimated depth and thickness of specific organs. We used several thin slices of ham to build a phantom with realistic attenuation. We placed radionuclide sources inside the phantom at different tissue depths and imaged it using an IVIS Spectrum (Perkin-Elmer, Waltham, MA, USA) and Inveon microPET (Preclinical Solutions Siemens, Knoxville, TN). We also performed CLI and PET of mouse models and applied the proposed attenuation model to correct CLI measurements. Using calibration factors obtained from phantom study that converts the corrected CLI measurements to %ID/g, we obtained an average difference of less that 10% for spleen and less than 35% for liver compared to conventional PET measurements. Hence, the proposed model has a capability of correcting the CLI signal to provide comparable measurements with PET data.

  5. Breaking the Depth Dependency of Phototherapy with Cerenkov Radiation and Low Radiance Responsive Nanophotosensitizers

    PubMed Central

    Kotagiri, Nalinikanth; Sudlow, Gail P.; Akers, Walter J.; Achilefu, Samuel

    2015-01-01

    The combination of light and photosensitizers for phototherapeutic interventions such as photodynamic therapy has transformed medicine and biology. However, the shallow penetration of light in tissues and the reliance on tissue oxygenation to generate cytotoxic radicals have limited the method to superficial or endoscope-accessible lesions. Here, we report a way to overcome these limitations by using Cerenkov radiation from radionuclides to activate an oxygen-independent nanophotosensitizer, titanium dioxide (TiO2). We show that administration of transferrin-coated TiO2 nanoparticles and clinical grade radionuclides in mice and co-localization in tumours resulted in either complete tumour remission or increased their median survival. Histological analysis of tumour sections showed selective destruction of cancerous cells and high numbers of tumour infiltrating lymphocytes, suggesting that both free radicals and the activation of the immune system mediated the destruction. Our results offer a way to harness low radiance-sensitive nanophotosensitizers to achieve depth-independent Cerenkov radiation-mediated therapy. PMID:25751304

  6. Preliminary Results from the UCLA/SLAC Ultra-High Gradient CerenkovWakefield Accelerator Experiment

    SciTech Connect

    Thompson, M.C.; Badakov, H.; Rosenzweig, J.B.; Travish, G.; Hogan, M.; Ischebeck, R.; Kirby, N.; Siemann, R.; Walz, D.; Muggli, P.; Scott, A.; Yoder, R.; /Manhattan Coll., Riverdale

    2008-02-06

    The first phase of an experiment to study the performance of dielectric Cerenkov wakefield accelerating structures at extremely high gradients in the GV/m range has been completed. This experiment takes advantage of the unique SLAC FFTB electron beam and its demonstrated ultra-short pulse lengths and high currents (e.g., {sigma}{sub z} = 20 {micro}m at Q = 3 nC). The FFTB electron beam has been successfully focused down and sent through varying lengths of fused silica capillary tubing with two different sizes: ID = 200 {micro}m/OD = 325 {micro}m and ID = 100 {micro}m/OD = 325 {micro}m. The pulse length of the electron beam was varied in the range 20 {micro}m < {sigma}{sub z} < 100 {micro}m which produced a range of electric fields between 2 and 20 GV/m at the inner surface of the dielectric tubes. We observed a sharp increase in optical emissions from the capillaries in the middle part of this surface field range which we believe indicates the transition between sustainable field levels and breakdown. If this initial interpretation is correct, the surfaced fields that were sustained equate to on axis accelerating field of several GV/m. In future experiments we plan to collect and measure coherent Cerenkov radiation emitted from the capillary tube to gain more information about the strength of the accelerating fields.

  7. Breaking the depth dependency of phototherapy with Cerenkov radiation and low-radiance-responsive nanophotosensitizers

    NASA Astrophysics Data System (ADS)

    Kotagiri, Nalinikanth; Sudlow, Gail P.; Akers, Walter J.; Achilefu, Samuel

    2015-05-01

    The combination of light and photosensitizers for phototherapeutic interventions, such as photodynamic therapy, has transformed medicine and biology. However, the shallow penetration of light into tissues and the reliance on tissue oxygenation to generate cytotoxic radicals have limited the method to superficial or endoscope-accessible lesions. Here we report a way to overcome these limitations by using Cerenkov radiation from radionuclides to activate an oxygen-independent nanophotosensitizer, titanium dioxide (TiO2). We show that the administration of transferrin-coated TiO2 nanoparticles and clinically used radionuclides in mice and colocalization in tumours results in either complete tumour remission or an increase in their median survival. Histological analysis of tumour sections showed the selective destruction of cancerous cells and high numbers of tumour-infiltrating lymphocytes, which suggests that both free radicals and the activation of the immune system mediated the destruction. Our results offer a way to harness low-radiance-sensitive nanophotosensitizers to achieve depth-independent Cerenkov-radiation-mediated therapy.

  8. Compliant Baffle for Large Telescope Daylight Imaging

    DTIC Science & Technology

    2014-09-01

    Compliant Baffle for Large Telescope Daylight Imaging Steven Griffin, Andrew Whiting, Shawn Haar The Boeing Company Stacie Williams Air Force...not impact wind loading induced jitter on the 3.6 m telescope . Analysis was performed to design a compliant baffle out of a synthetic fabric that...will be a comparison of angular rate sensors and accelerometers mounted on the telescope . 1.0 INTRODUCTION Unsteady wind loading is the largest

  9. Robotic Telescopes

    NASA Astrophysics Data System (ADS)

    Akerlof, C. W.

    2001-05-01

    Since the discovery of gamma-ray bursts, a number of groups have attempted to detect correlated optical transients from these elusive objects. Following the flight of the BATSE instrument on the Compton Gamma-Ray Observatory in 1991, a prompt burst coordinate alert service, BACODINE (now GCN) became available to ground-based telescopes. Several instruments were built to take advantage of this facility, culminating in the discovery of a bright optical flash associated with GRB990123. To date, that single observation remains unique - no other prompt flashes have been seen for a dozen or so other bursts observed with comparably short response times. Thus, GRB prompt optical luminosities may be considerably dimmer than observed for the GRB990123 event or even absent altogether. A new generation of instruments is prepared to explore these possibilties using burst coordinates provided by HETE-2, Swift, Ballerina, Agile and other satellite missions. These telescopes have response times as short as a few seconds and reach limiting magnitudes, m_v 20, guaranteeing a sensitivity sufficient to detect the afterglow many hours later. Results from these experiments should provide important new data about the dynamics and locale of GRBs.

  10. Development of a novel proton dosimetry system using an array of fiber-optic Cerenkov radiation sensors.

    PubMed

    Son, Jaeman; Kim, Meyoung; Shin, Dongho; Hwang, Uijung; Lee, Sebyeong; Lim, Youngkyung; Park, Jeonghoon; Park, Sung yong; Cho, Kwanho; Kim, Daeyong; Jang, Kyoung Won; Yoon, Myonggeun

    2015-12-01

    This study describes the development and evaluation of a new dosimetric system for proton therapy using an array of fiber-optic Cerenkov radiation sensors (AFCRS). The AFCRS was superior to a conventional, multi-layer ion chamber (MLIC) system in real-time data acquisition and cost effectiveness.

  11. Observation of Multi-TeV Gamma Rays from the Crab Nebula using the Tibet Air Shower Array.

    PubMed

    Amenomori; Ayabe; Cao; Danzengluobu; Ding; Feng; Fu; Guo; He; Hibino; Hotta; Huang; Huo; Izu; Jia; Kajino; Kasahara; Katayose; Labaciren; Li; Lu; Lu; Luo; Meng; Mizutani; Mu; Nanjo; Nishizawa; Ohnishi; Ohta; Ouchi; Ren; Saito; Sakata; Sasaki; Shi; Shibata; Shiomi; Shirai; Sugimoto; Taira; Tan; Tateyama; Torii; Utsugi; Wang; Wang; Xu; Yamamoto; Yu; Yuan; Yuda; Zhang; Zhang; Zhang; Zhang; Zhang; Zhaxisangzhu; Zhaxiciren; Zhou; Collaboration)

    1999-11-10

    The Tibet experiment, operating at Yangbajing (4300 m above sea level), is the lowest energy air shower array, and the new high-density array constructed in 1996 is sensitive to gamma-ray air showers at energies as low as 3 TeV. With this new array, the Crab Nebula was observed in multi-TeV gamma-rays and a signal was detected at the 5.5 sigma level. We also obtained the energy spectrum of gamma-rays in the energy region above 3 TeV which partially overlaps those observed with imaging atmospheric Cerenkov telescopes. The Crab spectrum observed in this energy region can be represented by the power-law fit dJ&parl0;E&parr0;&solm0;dE=&parl0;4.61+/-0.90&parr0;x10-12&parl0;E&solm0;3 TeV&parr0;-2.62+/-0.17 cm-2 s-1 TeV-1. This is the first observation of gamma-ray signals from point sources with a conventional air shower array using scintillation detectors.

  12. SYNCHROTRON RADIATION, FREE ELECTRON LASER, APPLICATION OF NUCLEAR TECHNOLOGY, ETC. Employing a Cerenkov detector for the thickness measurement of X-rays in a scattering background

    NASA Astrophysics Data System (ADS)

    Li, Shu-Wei; Kang, Ke-Jun; Wang, Yi; Li, Jin; Li, Yuan-Jing; Zhang, Qing-Jun

    2010-12-01

    The variation in environmental scattering background is a major source of systematic errors in X-ray inspection and measurement systems. As the energy of these photons consisting of environmental scattering background is much lower generally, the Cerenkov detectors having the detection threshold are likely insensitive to them and able to exclude their influence. A thickness measurement experiment is designed to verify the idea by employing a Cerenkov detector and an ionizing chamber for comparison. Furthermore, it is also found that the application of the Cerenkov detectors is helpful to exclude another systematic error from the variation of low energy components in the spectrum incident on the detector volume.

  13. Holographic telescope

    NASA Astrophysics Data System (ADS)

    Odhner, Jefferson E.

    2016-07-01

    Holographic optical elements (HOEs) work on the principal of diffraction and can in some cases replace conventional optical elements that work on the principal of refraction. An HOE can be thinner, lighter, can have more functionality, and can be lower cost than conventional optics. An HOE can serve as a beam splitter, spectral filter, mirror, and lens all at the same time. For a single wavelength system, an HOE can be an ideal solution but they have not been widely accepted for multispectral systems because they suffer from severe chromatic aberration. A refractive optical system also suffers from chromatic aberration but it is generally not as severe. To color correct a conventional refractive optical system, a flint glass and a crown glass are placed together such that the color dispersion of the flint and the crown cancel each other out making an achromatic lens (achromat) and the wavelengths all focus to the same point. The color dispersion of refractive lenses and holographic lenses are opposite from each other. In a diffractive optical system, long wavelengths focus closer (remember for HOEs: RBM "red bends more") than nominal focus while shorter wavelengths focus further out. In a refractive optical system, it is just the opposite. For this reason, diffractives can be incorporated into a refractive system to do the color correction and often cut down on the number of optical elements used [1.]. Color correction can also be achieved with an all-diffractive system by combining a holographic optical element with its conjugate. In this way the color dispersion of the first holographic optical element can be cancelled by the color dispersion of the second holographic optic. It is this technique that will be exploited in this paper to design a telescope made entirely of holographic optical elements. This telescope could be more portable (for field operations) the same technique could be used to make optics light enough for incorporation into a UAV.

  14. Registration of solar cosmic rays by Meteor-satellite Cerenkov counters

    NASA Astrophysics Data System (ADS)

    Avdiushin, S. I.; Kulagin, Iu. M.; Nazarova, M. N.; Pereiaslova, N. K.; Petrenko, I. E.; Svidskii, P. M.

    1984-11-01

    The Cerenkov proton counters installed as part of the radiometer instrumentation aboard the Meteor satellites are described, and measurements made with these counters during 1981 to 1984 in the range of energies from 10 MeV to greater than 600 MeV are analyzed. It is shown that the intensity of cosmic rays with an energy exceeding 600 MeV varies with the 11-year solar cycle, and that these variations occur in antiphase with variations of the solar-activity index. A constant south-north asymmetry of galactic proton fluxes with energies exceeding 600 MeV is reported for the first time. It is concluded that the data obtained can be used to develop an experimental model for predicting radiation effects on spacecraft.

  15. Development of CRID (Cerenkov Ring Imaging Detector) single electron wire detector

    SciTech Connect

    Aston, D.; Bean, A.; Bienz, T.; Bird, F.; Caldwell, D.; Cavalli-Sforza, M.; Coyle, P.; Coyne, D.; Dasu, S.; Dunwoodie, W.

    1989-02-01

    We describe the R and D effort to define the design parameters, method of construction and experimental results from the single electron wire detectors. These detectors will be used for particle identification using the Cerenkov Ring Imaging techniques in the SLD experiment at SLAC. We present measurements of pulse heights for several gases as a function of gas gain, charge division performance on a single electron signal using both 7 /mu/m and 33 /mu/m diameter carbon wires, photon feedback in TMAE laden gas, average pulse shape, and its comparison with the predicted shape and cross-talk. In addition, we present results of wire aging tests, and other tests associated with construction of this unusual type of wire chamber. 12 refs., 9 figs.

  16. A microwave inverse Cerenkov accelerator ({open_quotes}MICA{close_quotes})

    SciTech Connect

    Zhang, T.B.; Marshall, T.C.

    1995-12-31

    By {open_quotes}inverting{close_quotes} the stimulated Cerenkov effect to stimulated Cerenkov absorption, it is possible to build an electron accelerator device driven by high power microwaves that propagate in a slow-wave TM mode (axial E-field). An experiment now running at Brookhaven uses a powerful C02 laser and a 50MeV electron beam moving in a gas-loaded cell. Our approach is to use the 15MW available at 2.865GHz from a SLAC klystron to accelerate an electron beam provided from an rf gun ({approximately}6MeV, few psec pulses) to energy {approximately}20MeV. The use of microwaves permits a well defined group of electrons to be accelerated in a narrow window of phase. The waveguide is a cylinder, radius = 1.59cm, which contains an annular tube of alumina ({epsilon} = 9.4) having a hole about 1cm diameter, we show this will slow the waves to 0.9943c and permit electrons to be accelerated by a co-propagating field. This results in a relatively compact structure that has the advantage of a smooth-bore design and no need of magnetic focussing. We have solved for the wave dispersion in the structure, found the fields, and then used the Lorentz force equations to obtain the motion of a group of electrons distributed in radius and along the axis. We find the radial forces are focussing. Electrons in a well-defined filament (r < 0.5mm) remain collimated and do not strike the dielectric. Techniques for improving the dielectric breakdown of the surface should permit axial fields in the range of 100-200 kV/cm.

  17. Imaging phased telescope array study

    NASA Technical Reports Server (NTRS)

    Harvey, James E.

    1989-01-01

    The problems encountered in obtaining a wide field-of-view with large, space-based direct imaging phased telescope arrays were considered. After defining some of the critical systems issues, previous relevant work in the literature was reviewed and summarized. An extensive list was made of potential error sources and the error sources were categorized in the form of an error budget tree including optical design errors, optical fabrication errors, assembly and alignment errors, and environmental errors. After choosing a top level image quality requirment as a goal, a preliminary tops-down error budget allocation was performed; then, based upon engineering experience, detailed analysis, or data from the literature, a bottoms-up error budget reallocation was performed in an attempt to achieve an equitable distribution of difficulty in satisfying the various allocations. This exercise provided a realistic allocation for residual off-axis optical design errors in the presence of state-of-the-art optical fabrication and alignment errors. Three different computational techniques were developed for computing the image degradation of phased telescope arrays due to aberrations of the individual telescopes. Parametric studies and sensitivity analyses were then performed for a variety of subaperture configurations and telescope design parameters in an attempt to determine how the off-axis performance of a phased telescope array varies as the telescopes are scaled up in size. The Air Force Weapons Laboratory (AFWL) multipurpose telescope testbed (MMTT) configuration was analyzed in detail with regard to image degradation due to field curvature and distortion of the individual telescopes as they are scaled up in size.

  18. Optical aperture synthesis with electronically connected telescopes.

    PubMed

    Dravins, Dainis; Lagadec, Tiphaine; Nuñez, Paul D

    2015-04-16

    Highest resolution imaging in astronomy is achieved by interferometry, connecting telescopes over increasingly longer distances and at successively shorter wavelengths. Here, we present the first diffraction-limited images in visual light, produced by an array of independent optical telescopes, connected electronically only, with no optical links between them. With an array of small telescopes, second-order optical coherence of the sources is measured through intensity interferometry over 180 baselines between pairs of telescopes, and two-dimensional images reconstructed. The technique aims at diffraction-limited optical aperture synthesis over kilometre-long baselines to reach resolutions showing details on stellar surfaces and perhaps even the silhouettes of transiting exoplanets. Intensity interferometry circumvents problems of atmospheric turbulence that constrain ordinary interferometry. Since the electronic signal can be copied, many baselines can be built up between dispersed telescopes, and over long distances. Using arrays of air Cherenkov telescopes, this should enable the optical equivalent of interferometric arrays currently operating at radio wavelengths.

  19. Preliminary experimental investigation of an X-band Cerenkov-type high power microwave oscillator without guiding magnetic field

    NASA Astrophysics Data System (ADS)

    Guo, Liming; Shu, Ting; Li, Zhiqiang; Ju, Jinchuan; Fang, Xiaoting

    2017-02-01

    Among high power microwave (HPM) generators without guiding magnetic field, Cerenkov-type oscillator is expected to achieve a relatively high efficiency, which has already been realized in X-band in our previous simulation work. This paper presents the preliminary experimental investigations into an X-band Cerenkov-type HPM oscillator without guiding magnetic field. Based on the previous simulation structure, some modifications regarding diode structure were made. Different cathode structures and materials were tested in the experiments. By using a ring-shaped graphite cathode, microwave of about one hundred megawatt level was generated with a pure center frequency of 9.14 GHz, and an efficiency of about 1.3%. As analyzed in the paper, some practical issues reduce the efficiency in experiments, such as real features of the electron beam, probable breakdown regions on the cathode surface which can damage the diode, and so forth.

  20. TH-C-17A-02: New Radioluminescence Strategies Based On CRET (Cerenkov Radiation Energy Transfer) for Imaging and Therapy

    SciTech Connect

    Volotskova, O; Sun, C; Pratx, G; Xing, L

    2014-06-15

    Purpose: Cerenkov photons are produced when charged particles, emitted from radionuclides, travel through a media with a speed greater than that of the light in the media. Cerenkov radiation is mostly in the UV/Blue region and, thus, readily absorbed by biological tissue. Cerenkov Radiation Energy Transfer (CRET) is a wavelength-shifting phenomenon from blue Cerenkov light to more penetrating red wavelengths. We demonstrate the feasibility of in-depth imaging of CRET light originating from radionuclides realized by down conversion of gold nanoclusters (AuNCs, a novel particle composed of few atoms of gold coated with serum proteins) in vivo. Methods: Bovine Serum Albumin, Human Serum Albumin and Transferrin conjugated gold nanoclusters were synthesized, characterized and examined for CRET. Three different clinically used radiotracers: 18F-FDG, 90Y and 99mTc were used. Optical spectrum (440–750 nm) was recorded by sensitive bioluminescence imaging system at physiological temperature. Dose dependence (activity range from 0.5 up to 800uCi) and concentration dependence (0.01 to 1uM) studies were carried out. The compound was also imaged in a xenograft mouse model. Results: Only β+ and β--emitting radionuclides (18F-FDG, 90Y) are capable of CRET; no signal was found in 99mTc (γ-emitter). The emission peak of CRET by AuNCs was found to be ∼700 nm and was ∼3 fold times of background. In vitro studies showed a linear dependency between luminescence intensity and dose and concentration. CRET by gold nanoclusters was observed in xenografted mice injected with 100uCi of 18F-FDG. Conclusion: The unique optical, transport and chemical properties of AuNCs (gold nanoclusters) make them ideal candidates for in-vivo imaging applications. Development of new molecular imaging probes will allow us to achieve substantially improved spatiotemporal resolution, sensitivity and specificity for tumor imaging and detection.

  1. Light shift from ultraviolet to near infrared light: Cerenkov luminescence with gold nanocluster - near infrared (AuNc-NIR) conjugates

    NASA Astrophysics Data System (ADS)

    Yoo, Su Woong; Mun, Hyoyoung; Oh, Gyungseok; Ryu, Youngjae; Kim, Min-Gon; Chung, Euiheon

    2015-03-01

    Cerenkov luminescence (CL) is generated when a charged particle moves faster than the speed of light in dielectric media. Recently CL imaging becomes an emerging technique with the use of radioisotopes. However, due to relatively weak blue light production and massive tissue attenuation, CL has not been applied widely. Therefore, we attempted to shift the CL emission to more near infrared (NIR) spectrum for better tissue penetration by using Cerenkov Radiation Energy Transfer (CRET). Gold nanoclusters were conjugated with NIR dye molecules (AuNc-IR820 and AuNc-ICG) to be activated with ultraviolet light. We found optimal conjugate concentrations of AuNc-NIR conjugates by spectroscopy system to generate maximal photon emission. When exposed by ultraviolet light, the emission of NIR light from the conjugates were verified. In quantitative analysis, AuNc-NIR conjugates emit brighter light signal than pure AuNc. This result implies that NIR fluorescent dyes (both IR820 and ICG) can be excited by the emission from AuNc. Following the above baseline experiment, we mixed F-18 fluorodeoxyglucose (F-18 FDG) radioisotope to the AuNc- NIR conjugates, to confirm NIR emission induced from Cerenkov radiation. Long pass filter was used to block Cerenkov luminescence and to collect the emission from AuNc-NIR conjugates. Instead of one long exposure imaging with CCD, we used multiple frame scheme to eliminate gamma radiation strike in each frame prior to combination. In summary, we obtained NIR emission light from AuNc-NIR conjugated dyes that is induced from CL. We plan to perform in vivo small animal imaging with these conjugates to assess better tissue penetration.

  2. Does the Iron K and Alpha: Line of Active Galactic Nuclei Arise from the Cerenkov Line-like Radiation?

    NASA Technical Reports Server (NTRS)

    You, J. H.; Liu, D. B.; Chen, W. P.; Chen, L.; Zhang, S. N.

    2003-01-01

    When thermal relativistic electrons with isotropic distribution of velocities move in a gas region or impinge upon the surface of a cloud that consists of a dense gas or doped dusts, the Cerenkov effect produces peculiar atomic or ionic emission lines, which is known as the Cerenkov line - like radiation. This newly recognized emission mechanism may find wide applications in high-energy astrophysics. In this paper we tentatively adopt this new line emission mechanism to discuss the origin of the iron Kα feature of active galactic nuclei (AGNs). The motivation of this research is to attempt a solution to a problem encountered by the "disk fluorescence line" model, i.e. , the lack of temporal response of the observed iron Kα line flux to the changes of the X-ray continuum flux. If the Cerenkov line emission is indeed responsible significant ly for the iron Kα feature, the conventional scenario around the central supermassive black holes of AGNs would need to be modified to accomodate more energetic, more violent, and much denser environments than previously thought.

  3. Monte Carlo feasibility study for image guided surgery: from direct beta minus detection to Cerenkov luminescence imaging

    NASA Astrophysics Data System (ADS)

    Gigliotti, C. R.; Altabella, L.; Boschi, F.; Spinelli, A. E.

    2016-07-01

    The goal of this work is to compare the performances of different beta minus detection strategies for image guided surgery or ex vivo tissue analysis. In particular we investigated Cerenkov luminescence imaging (CLI) with and without the use of a radiator, direct and indirect beta detection and bremsstrahlung imaging using beta emitters commonly employed in Nuclear Medicine. Monte Carlo simulations were implemented using the GAMOS plug-in for GEANT4 considering a slab of muscle and a radioactive source (32P or 90Y) placed at 0.5 mm depth. We estimated the gain that can be obtained in terms of produced photons using different materials placed on the slab used as Cerenkov radiators, we then focused on the number of exiting photons and their spatial distribution for the different strategies. The use of radiator to enhance Cerenkov signal reduces the spatial resolution because of the increased optical spread. We found that direct beta detection and CLI are best approaches in term of resolution while the use of a thin scintillator increases the signal but the spatial resolution is degraded. Bremsstrahlung presents lower signal and it does not represent the best choice for image guided surgery. CLI represents a more flexible approach for image guided surgery using or ex vivo tissue analysis using beta-emitter imaging.

  4. Arrays vs. single telescopes

    NASA Astrophysics Data System (ADS)

    Johnson, H. L.

    The question of the relative efficiencies of telescope arrays versus an equivalent mirror-area very large telescope is re-examined and summarized. Four separate investigations by Bowen, Johnson and Richards, Code, and Disney all came to the same conclusion: that an array of telescopes is superior, both scientifically and economically, to a single very large telescope. The costs of recently completed telescopes are compared. The costs of arrays of telescopes are shown to be significantly lower than that of a single, very large telescope, with the further advantage that because existing, proven, designs can be used, no engineering 'break-throughs' are needed.

  5. RESEARCH NOTES FROM COLLABORATIONS: How to focus a Cherenkov telescope

    NASA Astrophysics Data System (ADS)

    Hofmann, W.

    2001-04-01

    Cherenkov telescopes image the Cherenkov emission from air showers. A priori, it is not obvious if the `best' images are achieved by measuring Cherenkov photon angles, i.e. focusing the telescope at infinity, or by considering the air shower as an object to be imaged, in which case one might focus the telescope on the central region of the shower. The issue is addressed using shower simulations.

  6. Upgrading and testing the 3D reconstruction of gamma-ray air showers as observed with an array of Cherenkov telescopes

    SciTech Connect

    Naumann-Godo, Melitta; Degrange, Bernard

    2008-12-24

    Stereoscopic arrays of Imaging Cherenkov Telescopes allow to reconstruct gamma-ray-induced showers in 3 dimensions. An analysis method based on a simple 3D-model of electromagnetic showers and implemented in the framework of the H.E.S.S. experiment was recently improved by an additional quality criterion which reduces the background contamination by a factor of about 2 in the case of extended sources, while hardly affecting gamma-ray selection efficiency. Moreover, the dramatic flares of PKS 2155-304 in July 2006, which provided H.E.S.S. data with an almost pure gamma-ray sample, offered the unique opportunity of a precision test of the 3D-reconstruction method as well as of the H.E.S.S. simulations used in its calibration. An agreement at a few percent level is found between data and simulations for the distributions of all 3D shower parameters.

  7. Linear permittivity tapering in a Cerenkov microwave source with a pre-bunched beam

    NASA Astrophysics Data System (ADS)

    Poole, B. R.; Harris, J. R.

    2013-04-01

    Cerenkov microwave sources use a dielectric-lined waveguide to reduce the velocity of the electromagnetic wave and provide efficient energy transfer between the wave and the driving electron beam. Tapering the permittivity of the dielectric to maintain synchronism between the beam and the wave as the beam loses energy can increase the efficiency of these devices. Here, we consider such a structure driven by an electron beam with a harmonic density perturbation. Particle-In-Cell (PIC) simulations and a macro-particle model based on the slowly varying envelope approximation are first used to examine an un-tapered baseline case. PIC simulations of the source with linear tapers over the entire amplifier length as well as over only a section of the amplifier where the beam executes synchrotron oscillations are examined. The efficiency for the baseline un-tapered source is 18%, while efficiencies up to approximately 48% are found using a taper in dielectric permittivity. Results of the best performing cases are presented. Detailed examination of longitudinal phase space, particle energy distributions, evolution of longitudinal wavenumber, and phase dynamics are presented from the PIC simulations.

  8. Cold test, spontaneous emission and gain in a rectangular Cerenkov amplifier

    SciTech Connect

    Scharer, J.E.; Joe, J.; Booske, J.H.; Basten, M.; Kirolous, H.

    1994-12-31

    The authors present experimental results for the rectangular Cerenkov grating amplifier. This research is being carried out to develop a Ka-band (35 GHz), low voltage (10 kV), moderate power (10 kW) source. They have constructed a Ku-band grating structure to study a scaled version of this source. The tapered grating consists of two tapered Ku-band smooth wave guide sections and two 3.5-inch sections of five-step-tapered gratings. Both tapered and untapered grating structures have been cold tested utilizing the network analyzer measurements. They find that their taper design reduced the reflection coefficient from {minus}5 dB to less than {minus}20 dB over a 12--15 GHz bandwidth. Spontaneous emission results resulting from passing the circular electron beam from a Litton thermionic gun over the grating structure will be presented. They have theoretically investigated the sheet beam interaction with hybrid modes in a deep groove rectangular grating waveguide. A complex dispersion relation, which includes a finite axial energy spread of the beam, describing the interaction has been solved. The authors find that the instability is always convective in the forward wave mode regime.

  9. Linear permittivity tapering in a Cerenkov microwave source with a pre-bunched beam

    SciTech Connect

    Poole, B. R.; Harris, J. R.

    2013-04-15

    Cerenkov microwave sources use a dielectric-lined waveguide to reduce the velocity of the electromagnetic wave and provide efficient energy transfer between the wave and the driving electron beam. Tapering the permittivity of the dielectric to maintain synchronism between the beam and the wave as the beam loses energy can increase the efficiency of these devices. Here, we consider such a structure driven by an electron beam with a harmonic density perturbation. Particle-In-Cell (PIC) simulations and a macro-particle model based on the slowly varying envelope approximation are first used to examine an un-tapered baseline case. PIC simulations of the source with linear tapers over the entire amplifier length as well as over only a section of the amplifier where the beam executes synchrotron oscillations are examined. The efficiency for the baseline un-tapered source is 18%, while efficiencies up to approximately 48% are found using a taper in dielectric permittivity. Results of the best performing cases are presented. Detailed examination of longitudinal phase space, particle energy distributions, evolution of longitudinal wavenumber, and phase dynamics are presented from the PIC simulations.

  10. Cerenkov radiation allows in vivo optical imaging of positron emitting radiotracers

    NASA Astrophysics Data System (ADS)

    Spinelli, Antonello E.; D'Ambrosio, Daniela; Calderan, Laura; Marengo, Mario; Sbarbati, Andrea; Boschi, Federico

    2010-01-01

    In this paper, we showed that Cerenkov radiation (CR) escaping from the surface of small living animals injected with 18F-FDG can be detected with optical imaging techniques. 18F decays by emitting positrons with a maximum energy of 0.635 MeV; such positrons, when travelling into tissues faster than the speed of light in the same medium, are responsible of CR emission. A detailed model of the CR spectrum considering the positron energy spectrum was developed in order to quantify the amount of light emission. The results presented in this work were obtained using a commercial optical imager equipped with charged coupled detectors (CCD). Our data open the door to optical imaging (OI) in vivo of the glucose metabolism, at least in pre-clinical research. We found that the heart and bladder can be clearly identified in the animal body reflecting the accumulation of the 18F-FDG. Moreover, we describe two different methods based on the spectral analysis of the CR that can be used to estimate the depth of the source inside the animal. We conclude that 18F-FDG can be employed as it is as a bimodal tracer for positron emission tomography (PET) and OI techniques. Our results are encouraging, suggesting that it could be possible to apply the proposed approach not only to β+ but also to pure β- emitters.

  11. Deep saturation of a Cerenkov wakefield amplified by an active medium

    NASA Astrophysics Data System (ADS)

    Toroker, Z.; Schächter, L.

    2015-07-01

    A trigger bunch of electrons traveling inside or in the vicinity of a dielectric medium generates a Cerenkov wake. If the dielectric medium is active, a small fraction of the spectrum of the wake is amplified and far behind the trigger bunch where the active medium is fully depleted, the amplitude and the phase of the wake are virtually constant. In this range, a second bunch of electrons trailing behind the trigger bunch can be accelerated. For optimal operation, the trigger bunch should be density modulated at the resonant frequency of the medium. However, we demonstrate that even if the bunch is uniform along many wavelengths we may still take advantage of the saturation characteristics to obtain conditions adequate for acceleration. Further we demonstrate that for large enough number of electrons it is possible to have a coherent amplified wake after a saturation length which is determined analytically and tested numerically. In addition, we show that almost 100% of the stored energy in the active medium can be transferred to the acceleration of the trailing bunch electrons. The relatively large energy spread due to the beam loading is well suited to a medical accelerator. When the beam loading is weak, the gradient is virtually constant but the acceleration efficiency drops to about 2% for typical parameters.

  12. Telescope performance at the Large Binocular Telescope

    NASA Astrophysics Data System (ADS)

    Hill, John M.; Rothberg, Barry; Christou, Julian C.; Summers, Kellee R.; Summers, Douglas M.

    2016-07-01

    The Large Binocular Telescope Observatory is a collaboration between institutions in Arizona, Germany, Italy, Indiana, Minnesota, Ohio and Virginia. The telescope uses two 8.4-m diameter primary mirrors mounted sideby- side on the same AZ-EL mount to produce a collecting area equivalent to an 11.8-meter aperture. Adaptive optics loops are routinely closed with natural stars on both sides for sided and combined beam observations. Rayleigh laser guide stars provide GLAO seeing improvement. With the telescope now in operation for 10 years, we report on various statistics of telescope performance and seeing-limited image quality. Statistics of telescope performance are reported in the areas of off-axis guiding, open-loop mount tracking, active optics and vibration. Delivered image quality is reported as measured by the DIMM and several guide cameras as a function of other parameters such as temperature and wind velocity. Projects to improve image quality and dome seeing are underway.

  13. The space telescope

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Papers concerning the development of the Space Telescope which were presented at the Twenty-first Annual Meeting of the American Astronautical Society in August, 1975 are included. Mission planning, telescope performance, optical detectors, mirror construction, pointing and control systems, data management, and maintenance of the telescope are discussed.

  14. Telescopes and space exploration

    NASA Technical Reports Server (NTRS)

    Brandt, J. C.; Maran, S. P.

    1976-01-01

    The necessity for different types of telescopes for astronomical investigations is discussed. Major findings in modern astronomy by ground-based and spaceborne telescopes are presented. Observations of the Crab Nebula, solar flares, interstellar gas, and the Black Hole are described. The theory of the oscillating universe is explored. Operating and planned telescopes are described.

  15. Enclosure of the Large Binocular Telescope

    NASA Astrophysics Data System (ADS)

    Salinari, Piero; Hill, John M.

    1994-06-01

    We describe the enclosure of the Large Binocular Telescope, now in a detailed design phase. The enclosure is co-rotating with the telescope, includes a service floor carrying all telescope utilities, and is characterized by two large portal shutters, which open laterally leaving the air flow at the front and at the back of the telescope essentially unobstructed. Large louvers on the side walls and wind shields with variable permeability at the front and back openings are used to control the air flow in different wind conditions. The inner and outer surfaces of the enclosure are designed to obtain short thermal time constant and close equilibrium with ambient air. Forced air circulation in the outer skin of the enclosure is used for better heat exchange and, with electrical heaters, for melting snow. The interaction of the whole building with the natural air flow in conditions representative of those encountered at the specific site on Mt. Graham was the subject of extensive water channel measurements on a model of the building and of the surrounding environment. The flow patterns obtained in the simulations show no mixing of lower air layers with those at the level of the primary mirrors or above. The handling scheme for large equipment, including the primary mirror cells and the bell-jar for aluminizing of the mirrors on board the telescope, is based on a large bridge crane that can transfer instruments and maintenance equipment to the telescope and to the service floor from the storage and maintenance area at ground level.

  16. EUSO-TA prototype telescope

    NASA Astrophysics Data System (ADS)

    Bisconti, Francesca

    2016-07-01

    EUSO-TA is one of the prototypes developed for the JEM-EUSO project, a space-based large field-of-view telescope to observe the fluorescence light emitted by cosmic ray air showers in the atmosphere. EUSO-TA is a ground-based prototype located at the Telescope Array (TA) site in Utah, USA, where an Electron Light Source and a Central Laser Facility are installed. The purpose of the EUSO-TA project is to calibrate the prototype with the TA fluorescence detector in presence of well-known light sources and cosmic ray air showers. In 2015, the detector started the first measurements and tests using the mentioned light sources have been performed successfully. A first cosmic ray candidate has been observed, as well as stars of different magnitude and color index. Since Silicon Photo-Multipliers (SiPMs) are very promising for fluorescence telescopes of next generation, they are under consideration for the realization of a new prototype of EUSO Photo Detector Module (PDM). The response of this sensor type is under investigation through simulations and laboratory experimentation.

  17. ATST telescope mount: telescope of machine tool

    NASA Astrophysics Data System (ADS)

    Jeffers, Paul; Stolz, Günter; Bonomi, Giovanni; Dreyer, Oliver; Kärcher, Hans

    2012-09-01

    The Advanced Technology Solar Telescope (ATST) will be the largest solar telescope in the world, and will be able to provide the sharpest views ever taken of the solar surface. The telescope has a 4m aperture primary mirror, however due to the off axis nature of the optical layout, the telescope mount has proportions similar to an 8 meter class telescope. The technology normally used in this class of telescope is well understood in the telescope community and has been successfully implemented in numerous projects. The world of large machine tools has developed in a separate realm with similar levels of performance requirement but different boundary conditions. In addition the competitive nature of private industry has encouraged development and usage of more cost effective solutions both in initial capital cost and thru-life operating cost. Telescope mounts move relatively slowly with requirements for high stability under external environmental influences such as wind buffeting. Large machine tools operate under high speed requirements coupled with high application of force through the machine but with little or no external environmental influences. The benefits of these parallel development paths and the ATST system requirements are being combined in the ATST Telescope Mount Assembly (TMA). The process of balancing the system requirements with new technologies is based on the experience of the ATST project team, Ingersoll Machine Tools who are the main contractor for the TMA and MT Mechatronics who are their design subcontractors. This paper highlights a number of these proven technologies from the commercially driven machine tool world that are being introduced to the TMA design. Also the challenges of integrating and ensuring that the differences in application requirements are accounted for in the design are discussed.

  18. Transient Self-Amplified Cerenkov Radiation with a Short Pulse Electron Beam

    SciTech Connect

    Poole, B R; Blackfield, D T; Camacho, J F

    2009-01-22

    An analytic and numerical examination of the slow wave Cerenkov free electron maser is presented. We consider the steady state amplifier configuration as well as operation in the selfamplified spontaneous emission (SASE) regime. The linear theory is extended to include electron beams that have a parabolic radial density inhomogeneity. Closed form solutions for the dispersion relation and modal structure of the electromagnetic field are determined in this inhomogeneous case. To determine the steady state response, a macro-particle approach is used to develop a set of coupled nonlinear ordinary differential equations for the amplitude and phase of the electromagnetic wave, which are solved in conjunction with the particle dynamical equations to determine the response when the system is driven as an amplifier with a time harmonic source. We then consider the case in which a fast rise time electron beam is injected into a dielectric loaded waveguide. In this case, radiation is generated by SASE, with the instability seeded by the leading edge of the electron beam. A pulse of radiation is produced, slipping behind the leading edge of the beam due to the disparity between the group velocity of the radiation and the beam velocity. Short pulses of microwave radiation are generated in the SASE regime and are investigated using particle-in-cell (PIC) simulations. The nonlinear dynamics are significantly more complicated in the transient SASE regime when compared with the steady state amplifier model due to the slippage of the radiation with respect to the beam. As strong self-bunching of the electron beam develops due to SASE, short pulses of superradiant emission develop with peak powers significantly larger than the predicted saturated power based on the steady state amplifier model. As these superradiant pulses grow, their pulse length decreases and forms a series of soliton-like pulses. Comparisons between the linear theory, macro-particle model, and PIC simulations are

  19. The Aerogel Cerenkov detector for the SHMS magnetic spectrometer in Hall C at Jefferson Lab

    SciTech Connect

    Horn, T.; Mkrtchyan, H.; Ali, S.; Asaturyan, A.; Carmignotto, M.; Dittmann, A.; Dutta, D.; Ent, R.; Hlavin, N.; Illieva, Y.; Mkrtchyan, A.; Nadel-Turonski, P.; Pegg, I.; Ramos, A.; Reinhold, J.; Sapkota, I.; Tadevosyan, V.; Zhamkochyan, S.; Wood, S. A.

    2017-01-01

    Hadronic reactions producing strange quarks such as exclusive or semi-inclusive kaon production, play an important role in studies of hadron structure and the dynamics that bind the most basic elements of nuclear physics. The small-angle capability of the new Super High Momentum Spectrometer (SHMS) in Hall C, coupled with its high momentum reach - up to the anticipated 11-GeV beam energy in Hall C - and coincidence capability with the well-understood High Momentum Spectrometer, will allow for probes of such hadron structure involving strangeness down to the smallest distance scales to date. To cleanly select the kaons, a threshold aerogel Cerenkov detector has been constructed for the SHMS. The detector consists of an aerogel tray followed by a diffusion box. Four trays for aerogel of nominal refractive indices of n=1.030, 1.020, 1.015 and 1.011 were constructed. The tray combination will allow for identification of kaons from 1 GeV/c up to 7.2 GeV/c, reaching 10-2 proton and 10-3 pion rejection, with kaon detection efficiency better than 95%. The diffusion box of the detector is equipped with 14 five-inch diameter photomultiplier tubes. Its interior walls are covered with Gore diffusive reflector, which is superior to the commonly used Millipore paper and improved the detector performance by 35%. The inner surface of the two aerogel trays with higher refractive index is covered with Millipore paper, however, those two trays with lower aerogel refractive index are again covered with Gore diffusive reflector for higher performance. The measured mean number of photoelectrons in saturation is ~12 for n=1.030, ~8 for n=1.020, ~10 for n=1.015, and ~5.5 for n=1.011. The design details, the results of component characterization, and initial performance tests and optimization of the detector are presented.

  20. The Aerogel Cerenkov detector for the SHMS magnetic spectrometer in Hall C at Jefferson Lab

    DOE PAGES

    Horn, T.; Mkrtchyan, H.; Ali, S.; ...

    2016-10-28

    Hadronic reactions producing strange quarks such as exclusive or semi-inclusive kaon production, play an important role in studies of hadron structure and the dynamics that bind the most basic elements of nuclear physics. The small-angle capability of the new Super High Momentum Spectrometer (SHMS) in Hall C, coupled with its high momentum reach - up to the anticipated 11-GeV beam energy in Hall C - and coincidence capability with the well-understood High Momentum Spectrometer, will allow for probes of such hadron structure involving strangeness down to the smallest distance scales to date. To cleanly select the kaons, a threshold aerogelmore » Cerenkov detector has been constructed for the SHMS. The detector consists of an aerogel tray followed by a diffusion box. Four trays for aerogel of nominal refractive indices of n=1.030, 1.020, 1.015 and 1.011 were constructed. The tray combination will allow for identification of kaons from 1 GeV/c up to 7.2 GeV/c, reaching 10-2 proton and 10-3 pion rejection, with kaon detection efficiency better than 95%. The diffusion box of the detector is equipped with 14 five-inch diameter photomultiplier tubes. Its interior walls are covered with Gore diffusive reflector, which is superior to the commonly used Millipore paper and improved the detector performance by 35%. The inner surface of the two aerogel trays with higher refractive index is covered with Millipore paper, however, those two trays with lower aerogel refractive index are again covered with Gore diffusive reflector for higher performance. The measured mean number of photoelectrons in saturation is ~12 for n=1.030, ~8 for n=1.020, ~10 for n=1.015, and ~5.5 for n=1.011. Here the design details, the results of component characterization, and initial performance tests and optimization of the detector are presented.« less

  1. Cerenkov ring imaging and spectroscopy of charged KSTAR interactions at 11 GeV/c

    SciTech Connect

    Bird, P.F.

    1988-11-01

    The physics and technology of this new Cerenkov detector are discussed, including materials studies, construction techniques, and resolution measurements. Sources of resolution error are individually identified and measured where possible. The results of all studied indicate that the measurement resolution is understood. This work has led to the adoption of a large scale ring imaging detector as part of a new high energy physics spectrometer, the SLD, at the Stanford Linear Accelerator Center. Results from an amplitude analysis of strange meson final states in K/sup /minus//p ..-->.. /ovr K/sub 0//..pi../sup /minus//p interactions are presented. The data derive from a 4 event/nb exposure of the LASS (large Aperture Superconducting Solenoid) spectrometer to an 11 GeV/c K/sup /minus// beam. The data sample consists of /approximately/100,000 vents distributed over the Dalitz plot of the channel. The process is observed to be dominated by the production and decay of natural spin-parity (J/sup P/ = 1/sup /minus//,2/sup +/,3/sup /minus//,/hor ellipsis/) strange meson states. The data can be understood in terms of a simple model in which the resonant /ovr K*/sup -// are produced predominantly via natural parity exchange in the t channel. The leading K*(890), K/sub 2/*(1430), and K*(1780) resonances are clearly observed and measured, and the underlying spectroscopy is also extracted. Indications of higher mass resonance production are also shown. The observed properties of these states are used to confront current models of quark spectroscopy in strange meson systems. 94 refs., 96 figs., 23 tabs.

  2. (68)Ga-labeled 3PRGD2 for dual PET and Cerenkov luminescence imaging of orthotopic human glioblastoma.

    PubMed

    Fan, Di; Zhang, Xin; Zhong, Lijun; Liu, Xujie; Sun, Yi; Zhao, Huiyun; Jia, Bing; Liu, Zhaofei; Zhu, Zhaohui; Shi, Jiyun; Wang, Fan

    2015-06-17

    β-Emitters can produce Cerenkov radiation that is detectable by Cerenkov luminescence imaging (CLI), allowing the combination of PET and CLI with one radiotracer for both tumor diagnosis and visual guidance during surgery. Recently, the clinical feasibility of CLI with the established therapeutic reagent Na(131)I and the PET tracer (18)F-FDG was demonstrated. (68)Ga possesses a higher Cerenkov light output than (18)F and (131)I, which would result in higher sensitivity for CLI and improve the outcome of CLI in clinical applications. However, the research on (68)Ga-based tumor-specific tracers for CLI is limited. In this study, we examined the use of (68)Ga-radiolabeled DOTA-3PRGD2 ((68)Ga-3PRGD2) for dual PET and CLI of orthotopic U87MG human glioblastoma. For this purpose, the Cerenkov efficiencies of (68)Ga and (18)F were measured with the IVIS Spectrum system (PerkinElmer, USA). The CLI signal intensity of (68)Ga was 15 times stronger than that of (18)F. PET and CLI of (68)Ga-3PRGD2 were performed in U87MG human glioblastoma xenografts. Both PET and CLI revealed a remarkable accumulation of (68)Ga-3PRGD2 in the U87MG human glioblastoma xenografts at 1 h p.i. with an extremely low background in the brain when compared with (18)F-FDG. Furthermore, (68)Ga-3PRGD2 was used for dual PET and CLI of orthotopic human glioblastoma. The orthotopic human glioblastoma was clearly visualized by both imaging modalities. In addition, the biodistribution of (68)Ga-3PRGD2 was assessed in normal mice to estimate the radiation dosimetry. The whole-body effective dose is 20.1 ± 3.3 μSv/MBq, which is equal to 3.7 mSv per whole-body PET scan with a 5 mCi injection dose. Thus, (68)Ga-3PRGD2 involves less radiation exposure in patients when compared with (18)F-FDG (7.0 mSv). The use of (68)Ga-3PRGD2 in dual PET and CLI shows great promise for tumor diagnosis and image-guided surgery.

  3. Space Infrared Telescope Facility (SIRTF) telescope overview

    NASA Technical Reports Server (NTRS)

    Schember, Helene; Manhart, Paul; Guiar, Cecilia; Stevens, James H.

    1991-01-01

    The Space Infrared Telescope Facility (SIRTF) will be the first true infrared observatory in space, building upon the technical and scientific experience gained through its two NASA survey-oriented predecessors: the Infrared Astronomical Satellite and the Cosmic Background Explorer. During its minimum five year lifetime, the SIRTF will perform pointed scientific observations at wavelengths from 1.8 to 1200 microns with an increase in sensitivity over previous missions of several orders of magnitude. This paper discusses a candidate design for the SIRTF telescope, encompassing optics, cryostat, and instrument accommodation, which has been undertaken to provide a fulcrum for the development of functional requirements, interface definition, risk assessment and cost. The telescope optics employ a baffled Ritchey-Chretien Cassegrain system with a 1-m class primary mirror, an active secondary mirror, and a stationary facetted tertiary mirror. The optics are embedded in a large superfluid He cryostat designed to maintain the entire telescope-instrument system at temperatures below 3 K.

  4. Hubble Space Telescope Optical Telescope Assembly

    NASA Technical Reports Server (NTRS)

    1986-01-01

    This image illustrates the Hubble Space Telescope's (HST's) Optical Telescope Assembly (OTA). One of the three major elements of the HST, the OTA consists of two mirrors (a primary mirror and a secondary mirror), support trusses, and the focal plane structure. The mirrors collect and focus light from selected celestial objects and are housed near the center of the telescope. The primary mirror captures light from objects in space and focuses it toward the secondary mirror. The secondary mirror redirects the light to a focal plane where the Scientific Instruments are located. The primary mirror is 94.5 inches (2.4 meters) in diameter and the secondary mirror is 12.2 inches (0.3 meters) in diameter. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth Orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The HST detects objects 25 times fainter than the dimmest objects seen from the Earth and provides astronomers with an observable universe 250 times larger than visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The spacecraft is 42.5 feet (13 meters) long and weighs 25,000 pounds (11,600 kilograms). The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Cornecticut, developed the optical system and guidance sensors. The Lockheed Missile and Space Company of Sunnyvale, California produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope.

  5. Liverpool Telescope and Liverpool Telescope 2

    NASA Astrophysics Data System (ADS)

    Copperwheat, C. M.; Steele, I. A.; Barnsley, R. M.; Bates, S. D.; Clay, N. R.; Jermak, H.; Marchant, J. M.; Mottram, C. J.; Piascik, A.; Smith, R. J.

    2016-12-01

    The Liverpool Telescope is a fully robotic optical/near-infrared telescope with a 2-metre clear aperture, located at the Observatorio del Roque de los Muchachos on the Canary Island of La Palma. The telescope is owned and operated by Liverpool John Moores University, with financial support from the UK's Science and Technology Facilities Council. The telescope began routine science operations in 2004 and is a common-user facility with time available through a variety of committees via an open, peer reviewed process. Seven simultaneously mounted instruments support a broad science programme, with a focus on transient follow-up and other time domain topics well suited to the characteristics of robotic observing. Development has also begun on a successor facility, with the working title `Liverpool Telescope 2', to capitalise on the new era of time domain astronomy which will be brought about by the next generation of survey facilities such as LSST. The fully robotic Liverpool Telescope 2 will have a 4-metre aperture and an improved response time. In this paper we provide an overview of the current status of both facilities.

  6. Measurement of the Li/B abundance ratio above 650 MeV/nucleon. [by balloon-borne cosmic ray telescope

    NASA Technical Reports Server (NTRS)

    Byrnak, B.; Lund, N.; Rasmussen, I. L.; Rotenberg, M.

    1978-01-01

    A balloon-borne cosmic-ray telescope containing 4 Cerenkov counters and a neon flash tube hodoscope was flown from Sioux City, Iowa in September 1974. The data have been reanalyzed, using information of flashed tubes to reject events due to proton and He interactions. The new event selection has reduced charge overlap between He and Li to an insignificant level, so that abundance ratios involving Li can now be measured with the instrument. Precise correction factors for events lost by inefficiency of the hodoscope have been derived from flight data; they lead to improved accuracy in measurements of light elements.

  7. Operations at the JPL OCTL Telescope

    NASA Technical Reports Server (NTRS)

    Wilson, Keith E.; Kovalik, Joseph M.; Biswas, Abhijit; Roberts, William T.

    2007-01-01

    The JPL Optical Communications Telescope Laboratory (OCTL) is a 200 sq-m located at 2.2.km altitude in Wrightwood California and houses a state-of-the-art 1-m telescope. The OCTL team is involved in the development of operational strategies for ground-to-space laser beam propagation for future NASA optical communications missions. Strategies include safe beam propagation through navigable air space, line of sight optical attenuation monitoring, adaptive optics, and multi-beam scintillation mitigation. This paper presents the results of recent operations at the OCTL facility including telescope characterization data and laser beam propagation experiments to Earth-orbiting retro-reflecting satellites; experiments that validate the telescope's tracking and blind-pointing performance and safe laser beam transmission procedures for propagating through navigable airspace.

  8. JWST Pathfinder Telescope Integration

    NASA Technical Reports Server (NTRS)

    Matthews, Gary W.; Kennard, Scott H.; Broccolo, Ronald T.; Ellis, James M.; Daly, Elizabeth A.; Hahn, Walter G.; Amon, John N.; Mt. Pleasant, Stephen M.; Texter, Scott; Atkinson, Charles B.; McKay, Andrew; Levi, Joshua; Keski-Kuha, Ritva; Feinberg, Lee

    2015-01-01

    The James Webb Space Telescope (JWST) is a 6.5m, segmented, IR telescope that will explore the first light of the universe after the big bang. In 2014, a major risk reduction effort related to the Alignment, Integration, and Test (AI&T) of the segmented telescope was completed. The Pathfinder telescope includes two Primary Mirror Segment Assemblies (PMSA's) and the Secondary Mirror Assembly (SMA) onto a flight-like composite telescope backplane. This pathfinder allowed the JWST team to assess the alignment process and to better understand the various error sources that need to be accommodated in the flight build. The successful completion of the Pathfinder Telescope provides a final integration roadmap for the flight operations that will start in August 2015.

  9. The Solar Telescope GREGOR

    NASA Astrophysics Data System (ADS)

    Volkmer, R.

    2008-09-01

    During the last years the new 1.5m solar telescope GREGOR was assembled at Izania on Tenerife, Spain. The telescope is designed for high-precision measurements of the magnetic field in the solar photosphere and chromosphere with a resolution of 70km on the Sun. The telescope concept offers also high resolution stellar spectroscopy. The telescope is build by a consortium of the Kiepenheuer-Institut für Sonnenphysik, the Astrophysikalische Institut Potsdam, the Institut für Astrophysik Göttingen, Max-Plank-Institut für Sonnensystemforschung and additional international Partners. The telescope is a complete open structure with active cooled main mirror. High performance post-focus instruments in the visible and near IR wavelength acquire high resolution spectra with 2 dimensional spatial resolution and polarimetric information. The commissioning of the telescope will start in 2008 to allow first science observations at the end of 2009.

  10. Automated telescope scheduling

    NASA Technical Reports Server (NTRS)

    Johnston, Mark D.

    1988-01-01

    With the ever increasing level of automation of astronomical telescopes the benefits and feasibility of automated planning and scheduling are becoming more apparent. Improved efficiency and increased overall telescope utilization are the most obvious goals. Automated scheduling at some level has been done for several satellite observatories, but the requirements on these systems were much less stringent than on modern ground or satellite observatories. The scheduling problem is particularly acute for Hubble Space Telescope: virtually all observations must be planned in excruciating detail weeks to months in advance. Space Telescope Science Institute has recently made significant progress on the scheduling problem by exploiting state-of-the-art artificial intelligence software technology. What is especially interesting is that this effort has already yielded software that is well suited to scheduling groundbased telescopes, including the problem of optimizing the coordinated scheduling of more than one telescope.

  11. Airborne Infrared Astronomical Telescopes

    NASA Astrophysics Data System (ADS)

    Erickson, Edwin F.

    2017-01-01

    A unique program of infrared astronomical observations from aircraft evolved at NASA’s Ames Research Center, beginning in the 1960s. Telescopes were flown on a Convair 990, a Lear Jet, and a Lockheed C-141 - the Kuiper Airborne Observatory (KAO) - leading to the planning and development of SOFIA: a 2.7 m telescope now flying on a Boeing 747SP. The poster describes these telescopes and highlights of some of the scientific results obtained from them.

  12. The Aerogel Cerenkov detector for the SHMS magnetic spectrometer in Hall C at Jefferson Lab

    SciTech Connect

    Horn, T.; Mkrtchyan, H.; Ali, S.; Asaturyan, A.; Carmignotto, M.; Dittmann, A.; Dutta, D.; Ent, R.; Hlavin, N.; Illieva, Y.; Mkrtchyan, A.; Nadel-Turonski, P.; Pegg, I.; Ramos, A.; Reinhold, J.; Sapkota, I.; Tadevosyan, V.; Zhamkochyan, S.; Wood, S. A.

    2016-10-28

    Hadronic reactions producing strange quarks such as exclusive or semi-inclusive kaon production, play an important role in studies of hadron structure and the dynamics that bind the most basic elements of nuclear physics. The small-angle capability of the new Super High Momentum Spectrometer (SHMS) in Hall C, coupled with its high momentum reach - up to the anticipated 11-GeV beam energy in Hall C - and coincidence capability with the well-understood High Momentum Spectrometer, will allow for probes of such hadron structure involving strangeness down to the smallest distance scales to date. To cleanly select the kaons, a threshold aerogel Cerenkov detector has been constructed for the SHMS. The detector consists of an aerogel tray followed by a diffusion box. Four trays for aerogel of nominal refractive indices of n=1.030, 1.020, 1.015 and 1.011 were constructed. The tray combination will allow for identification of kaons from 1 GeV/c up to 7.2 GeV/c, reaching 10-2 proton and 10-3 pion rejection, with kaon detection efficiency better than 95%. The diffusion box of the detector is equipped with 14 five-inch diameter photomultiplier tubes. Its interior walls are covered with Gore diffusive reflector, which is superior to the commonly used Millipore paper and improved the detector performance by 35%. The inner surface of the two aerogel trays with higher refractive index is covered with Millipore paper, however, those two trays with lower aerogel refractive index are again covered with Gore diffusive reflector for higher performance. The measured mean number of photoelectrons in saturation is ~12 for n=1.030, ~8 for n=1.020, ~10 for n=1.015, and ~5.5 for n=1.011. Here the design details, the results of component characterization, and initial performance tests and optimization of the detector are presented.

  13. Monte Carlo studies of medium-size telescope designs for the Cherenkov Telescope Array

    NASA Astrophysics Data System (ADS)

    Wood, M.; Jogler, T.; Dumm, J.; Funk, S.

    2016-01-01

    We present studies for optimizing the next generation of ground-based imaging atmospheric Cherenkov telescopes (IACTs). Results focus on mid-sized telescopes (MSTs) for CTA, detecting very high energy gamma rays in the energy range from a few hundred GeV to a few tens of TeV. We describe a novel, flexible detector Monte Carlo package, FAST (FAst Simulation for imaging air cherenkov Telescopes), that we use to simulate different array and telescope designs. The simulation is somewhat simplified to allow for efficient exploration over a large telescope design parameter space. We investigate a wide range of telescope performance parameters including optical resolution, camera pixel size, and light collection area. In order to ensure a comparison of the arrays at their maximum sensitivity, we analyze the simulations with the most sensitive techniques used in the field, such as maximum likelihood template reconstruction and boosted decision trees for background rejection. Choosing telescope design parameters representative of the proposed Davies-Cotton (DC) and Schwarzchild-Couder (SC) MST designs, we compare the performance of the arrays by examining the gamma-ray angular resolution and differential point-source sensitivity. We further investigate the array performance under a wide range of conditions, determining the impact of the number of telescopes, telescope separation, night sky background, and geomagnetic field. We find a 30-40% improvement in the gamma-ray angular resolution at all energies when comparing arrays with an equal number of SC and DC telescopes, significantly enhancing point-source sensitivity in the MST energy range. We attribute the increase in point-source sensitivity to the improved optical point-spread function and smaller pixel size of the SC telescope design.

  14. Monte Carlo studies of medium-size telescope designs for the Cherenkov Telescope Array

    DOE PAGES

    Wood, M. D.; Jogler, T.; Dumm, J.; ...

    2015-06-07

    In this paper, we present studies for optimizing the next generation of ground-based imaging atmospheric Cherenkov telescopes (IACTs). Results focus on mid-sized telescopes (MSTs) for CTA, detecting very high energy gamma rays in the energy range from a few hundred GeV to a few tens of TeV. We describe a novel, flexible detector Monte Carlo package, FAST (FAst Simulation for imaging air cherenkov Telescopes), that we use to simulate different array and telescope designs. The simulation is somewhat simplified to allow for efficient exploration over a large telescope design parameter space. We investigate a wide range of telescope performance parametersmore » including optical resolution, camera pixel size, and light collection area. In order to ensure a comparison of the arrays at their maximum sensitivity, we analyze the simulations with the most sensitive techniques used in the field, such as maximum likelihood template reconstruction and boosted decision trees for background rejection. Choosing telescope design parameters representative of the proposed Davies–Cotton (DC) and Schwarzchild–Couder (SC) MST designs, we compare the performance of the arrays by examining the gamma-ray angular resolution and differential point-source sensitivity. We further investigate the array performance under a wide range of conditions, determining the impact of the number of telescopes, telescope separation, night sky background, and geomagnetic field. We find a 30–40% improvement in the gamma-ray angular resolution at all energies when comparing arrays with an equal number of SC and DC telescopes, significantly enhancing point-source sensitivity in the MST energy range. Finally, we attribute the increase in point-source sensitivity to the improved optical point-spread function and smaller pixel size of the SC telescope design.« less

  15. Monte Carlo studies of medium-size telescope designs for the Cherenkov Telescope Array

    SciTech Connect

    Wood, M. D.; Jogler, T.; Dumm, J.; Funk, S.

    2015-06-07

    In this paper, we present studies for optimizing the next generation of ground-based imaging atmospheric Cherenkov telescopes (IACTs). Results focus on mid-sized telescopes (MSTs) for CTA, detecting very high energy gamma rays in the energy range from a few hundred GeV to a few tens of TeV. We describe a novel, flexible detector Monte Carlo package, FAST (FAst Simulation for imaging air cherenkov Telescopes), that we use to simulate different array and telescope designs. The simulation is somewhat simplified to allow for efficient exploration over a large telescope design parameter space. We investigate a wide range of telescope performance parameters including optical resolution, camera pixel size, and light collection area. In order to ensure a comparison of the arrays at their maximum sensitivity, we analyze the simulations with the most sensitive techniques used in the field, such as maximum likelihood template reconstruction and boosted decision trees for background rejection. Choosing telescope design parameters representative of the proposed Davies–Cotton (DC) and Schwarzchild–Couder (SC) MST designs, we compare the performance of the arrays by examining the gamma-ray angular resolution and differential point-source sensitivity. We further investigate the array performance under a wide range of conditions, determining the impact of the number of telescopes, telescope separation, night sky background, and geomagnetic field. We find a 30–40% improvement in the gamma-ray angular resolution at all energies when comparing arrays with an equal number of SC and DC telescopes, significantly enhancing point-source sensitivity in the MST energy range. Finally, we attribute the increase in point-source sensitivity to the improved optical point-spread function and smaller pixel size of the SC telescope design.

  16. Detail of front west entry showing telescoping pilasters and decorative ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail of front west entry showing telescoping pilasters and decorative crawl space vents, facing east. - Albrook Air Force Station, Dispensary, East side of Canfield Avenue, Balboa, Former Panama Canal Zone, CZ

  17. High resolution telescope

    DOEpatents

    Massie, Norbert A.; Oster, Yale

    1992-01-01

    A large effective-aperture, low-cost optical telescope with diffraction-limited resolution enables ground-based observation of near-earth space objects. The telescope has a non-redundant, thinned-aperture array in a center-mount, single-structure space frame. It employs speckle interferometric imaging to achieve diffraction-limited resolution. The signal-to-noise ratio problem is mitigated by moving the wavelength of operation to the near-IR, and the image is sensed by a Silicon CCD. The steerable, single-structure array presents a constant pupil. The center-mount, radar-like mount enables low-earth orbit space objects to be tracked as well as increases stiffness of the space frame. In the preferred embodiment, the array has elemental telescopes with subaperture of 2.1 m in a circle-of-nine configuration. The telescope array has an effective aperture of 12 m which provides a diffraction-limited resolution of 0.02 arc seconds. Pathlength matching of the telescope array is maintained by an electro-optical system employing laser metrology. Speckle imaging relaxes pathlength matching tolerance by one order of magnitude as compared to phased arrays. Many features of the telescope contribute to substantial reduction in costs. These include eliminating the conventional protective dome and reducing on-site construction activites. The cost of the telescope scales with the first power of the aperture rather than its third power as in conventional telescopes.

  18. Video Telescope Operating Microscopy.

    PubMed

    Divers, Stephen J

    2015-09-01

    Exotic pet veterinarians frequently have to operate on small animals, and magnification is commonly used. Existing endoscopy equipment can be used with a mechanical arm and telescope to enable video telescope operating microscopy. The additional equipment items and their specifics are described, and several case examples are provided.

  19. Goddard Robotic Telescope

    SciTech Connect

    Sakamoto, Takanori; Donato, Davide; Gehrels, Neil; Okajima, Takashi; Ukwatta, Tilan N.

    2009-05-25

    We are constructing the 14'' fully automated optical robotic telescope, Goddard Robotic Telescope (GRT), at the Goddard Geophysical and Astronomical Observatory. The aims of our robotic telescope are 1) to follow-up the Swift/Fermi Gamma-Ray Bursts (GRBs) and 2) to perform the coordinated optical observations of the Fermi/Large Area Telescope (LAT) Active Galactic Nuclei (AGN). Our telescope system consists of the 14'' Celestron Optical Telescope Assembly (OTA), the Astro-Physics 1200GTO mount, the Apogee U47 CCD camera, the JMI's electronic focuser, and the Finger Lake Instrumentation's color filter wheel with U, B, V, R and I filters. With the focal reducer, 20'x20' field of view has been achieved. The observatory dome is the Astro Haven's 7 ft clam-shell dome. We started the scientific observations on mid-November 2008. While not observing our primary targets (GRBs and AGNs), we are planning to open our telescope time to the public for having a wider use of our telescope in both a different research field and an educational purpose.

  20. Telescope Adaptive Optics Code

    SciTech Connect

    Phillion, D.

    2005-07-28

    The Telescope AO Code has general adaptive optics capabilities plus specialized models for three telescopes with either adaptive optics or active optics systems. It has the capability to generate either single-layer or distributed Kolmogorov turbulence phase screens using the FFT. Missing low order spatial frequencies are added using the Karhunen-Loeve expansion. The phase structure curve is extremely dose to the theoreUcal. Secondly, it has the capability to simulate an adaptive optics control systems. The default parameters are those of the Keck II adaptive optics system. Thirdly, it has a general wave optics capability to model the science camera halo due to scintillation from atmospheric turbulence and the telescope optics. Although this capability was implemented for the Gemini telescopes, the only default parameter specific to the Gemini telescopes is the primary mirror diameter. Finally, it has a model for the LSST active optics alignment strategy. This last model is highly specific to the LSST

  1. The solar optical telescope

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Objectives of the Solar Optical Telescope are to study the physics of the Sun on the scale at which many of the important physical processes occur and to attain a resolution of 73km on the Sun or 0.1 arc seconds of angular resolution. Topics discussed in this overview of the Solar Optical Telescope include: why is the Solar Optical Telescope needed; current picture of the Sun's atmosphere and convection zone; scientific problems for the Solar Optical Telescope; a description of the telescope; the facility - science management, contamination control, and accessibility to the instruments; the scientific instruments - a coordinated instrument package for unlocking the Sun's secrets; parameters of the coordinated instrument package; science operations from the Space Shuttle; and the dynamic solar atmosphere.

  2. Networked Automatic Optical Telescopes

    NASA Astrophysics Data System (ADS)

    Mattox, J. R.

    2000-05-01

    Many groups around the world are developing automated or robotic optical observatories. The coordinated operation of automated optical telescopes at diverse sites could provide observing prospects which are not otherwise available, e.g., continuous optical photometry without diurnal interruption. Computer control and scheduling also offers the prospect of effective response to transient events such as γ -ray bursts. These telescopes could also serve science education by providing high-quality CCD data for educators and students. The Automatic Telescope Network (ATN) project has been undertaken to promote networking of automated telescopes. A web site is maintained at http://gamma.bu.edu/atn/. The development of such networks will be facilitated by the existence of standards. A set of standard commands for instrument and telescope control systems will allow for the creation of software for an ``observatory control system'' which can be used at any facility which complies with the TCS and ICS standards. Also, there is a strong need for standards for the specification of observations to be done, and reports on the results and status of observations. A proposed standard for this is the Remote Telescope Markup Language (RTML), which is expected to be described in another poster in this session. It may thus be feasible for amateur-astronomers to soon buy all necessary equipment and software to field an automatic telescope. The owner/operator could make otherwise unused telescope time available to the network in exchange for the utilization of other telescopes in the network --- including occasional utilization of meter-class telescopes with research-grade CCD detectors at good sites.

  3. Optical aperture synthesis with electronically connected telescopes

    PubMed Central

    Dravins, Dainis; Lagadec, Tiphaine; Nuñez, Paul D.

    2015-01-01

    Highest resolution imaging in astronomy is achieved by interferometry, connecting telescopes over increasingly longer distances and at successively shorter wavelengths. Here, we present the first diffraction-limited images in visual light, produced by an array of independent optical telescopes, connected electronically only, with no optical links between them. With an array of small telescopes, second-order optical coherence of the sources is measured through intensity interferometry over 180 baselines between pairs of telescopes, and two-dimensional images reconstructed. The technique aims at diffraction-limited optical aperture synthesis over kilometre-long baselines to reach resolutions showing details on stellar surfaces and perhaps even the silhouettes of transiting exoplanets. Intensity interferometry circumvents problems of atmospheric turbulence that constrain ordinary interferometry. Since the electronic signal can be copied, many baselines can be built up between dispersed telescopes, and over long distances. Using arrays of air Cherenkov telescopes, this should enable the optical equivalent of interferometric arrays currently operating at radio wavelengths. PMID:25880705

  4. Two Easily Made Astronomical Telescopes.

    ERIC Educational Resources Information Center

    Hill, M.; Jacobs, D. J.

    1991-01-01

    The directions and diagrams for making a reflecting telescope and a refracting telescope are presented. These telescopes can be made by students out of plumbing parts and easily obtainable, inexpensive, optical components. (KR)

  5. The large binocular telescope.

    PubMed

    Hill, John M

    2010-06-01

    The Large Binocular Telescope (LBT) Observatory is a collaboration among institutions in Arizona, Germany, Italy, Indiana, Minnesota, Ohio, and Virginia. The telescope on Mount Graham in Southeastern Arizona uses two 8.4 m diameter primary mirrors mounted side by side. A unique feature of the LBT is that the light from the two Gregorian telescope sides can be combined to produce phased-array imaging of an extended field. This cophased imaging along with adaptive optics gives the telescope the diffraction-limited resolution of a 22.65 m aperture and a collecting area equivalent to an 11.8 m circular aperture. This paper describes the design, construction, and commissioning of this unique telescope. We report some sample astronomical results with the prime focus cameras. We comment on some of the technical challenges and solutions. The telescope uses two F/15 adaptive secondaries to correct atmospheric turbulence. The first of these adaptive mirrors has completed final system testing in Firenze, Italy, and is planned to be at the telescope by Spring 2010.

  6. The GREGOR Solar Telescope

    NASA Astrophysics Data System (ADS)

    Denker, C.; Lagg, A.; Puschmann, K. G.; Schmidt, D.; Schmidt, W.; Sobotka, M.; Soltau, D.; Strassmeier, K. G.; Volkmer, R.; von der Luehe, O.; Solanki, S. K.; Balthasar, H.; Bello Gonzalez, N.; Berkefeld, T.; Collados Vera, M.; Hofmann, A.; Kneer, F.

    2012-12-01

    The 1.5-meter GREGOR solar telescope is a new facility for high-resolution observations of the Sun. The telescope is located at the Spanish Observatorio del Teide on Tenerife. The telescope incorporates advanced designs for a foldable-tent dome, an open steel-truss telescope structure, and active and passive means to minimize telescope and mirror seeing. Solar fine structure can be observed with a dedicated suite of instruments: a broad-band imaging system, the "GREGOR Fabry-Perot Interferometer", and the "Grating Infrared Spectrograph". All post-focus instruments benefit from a high-order (multi-conjugate) adaptive optics system, which enables observations close to the diffraction limit of the telescope. The inclusion of a spectrograph for stellar activity studies and the search for solar twins expands the scientific usage of the GREGOR to the nighttime domain. We report on the successful commissioning of the telescope until the end of 2011 and the first steps towards science verification in 2012.

  7. Gemini telescope structure design

    NASA Astrophysics Data System (ADS)

    Raybould, Keith; Gillett, Paul E.; Hatton, Peter; Pentland, Gordon; Sheehan, Mike; Warner, Mark

    1994-06-01

    The Gemini project is an international collaboration to design, fabricate, and assemble two 8 M telescopes, one on Mauna Kea in Hawaii, the other on Cerro Pachon in Chile. The telescopes will be national facilities designed to meet the Gemini Science Requirements (GSR), a document developed by the Gemini Science Committee (GSC) and the national project scientists. The Gemini telescope group, based on Tucson, has developed a telescope structure to meet the GSR. This paper describes the science requirements that have technically driven the design, and the features that have been incorporated to meet these requirements. This is followed by a brief description of the telescope design. Finally, analyses that have been performed and development programs that have been undertaken are described briefly. Only the designs that have been performed by the Gemini Telescope Structure, Building and Enclosure Group are presented here; control, optical systems, acquisition and guiding, active and adaptive optics, Cassegrain rotator and instrumentation issues are designed and managed by others and will not be discussed here, except for a brief description of the telescope configurations to aid subsequent discussions.

  8. Simulation of a gigawatt level Ku-band overmoded Cerenkov type oscillator operated at low guiding magnetic field

    NASA Astrophysics Data System (ADS)

    Zhang, Hua; Shu, Ting; Ju, Jinchuan; Wu, Dapeng

    2014-03-01

    We present the simulation results of a Ku-band overmoded Cerenkov type high power microwave oscillator. A guiding magnetic field as low as 0.6 T has been operated in the device. Overmoded slow wave structures with gradually tapered vanes are used in order to increase power capacity and the efficiency of beam-wave interaction. The drift cavity is adopted to enhance the beam-wave interaction of the device. After numerical optimization, the designed generator with an output microwave power of 1.2 GW, a frequency of 13.8 GHz, and a power conversion efficiency as high as 38% can be achieved, when the diode voltage and current are, respectively, 540 kV and 5.8 kA. The power compositions of TM0n modes of the output microwave have been analyzed, the results of which show that TM01 mode takes over almost 95% of the power proportion.

  9. Sensitivity improvement of Cerenkov luminescence endoscope with terbium doped Gd{sub 2}O{sub 2}S nanoparticles

    SciTech Connect

    Cao, Xin; Chen, Xueli E-mail: jimleung@mail.xidian.edu.cn; Cao, Xu; Zhan, Yonghua; Liang, Jimin E-mail: jimleung@mail.xidian.edu.cn; Kang, Fei; Wang, Jing; Wu, Kaichun

    2015-05-25

    Our previous study showed a great attenuation for the Cerenkov luminescence endoscope (CLE), resulting in relatively low detection sensitivity of radiotracers. Here, a kind of radioluminescence nanoparticles (RLNPs), terbium doped Gd{sub 2}O{sub 2}S was mixed with the radionuclide {sup 68}Ga to enhance the intensity of emitted luminescence, which finally improved the detection sensitivity of the CLE by using the radioluminescence imaging technique. With the in vitro and in vivo pseudotumor experiments, we showed that the use of RLNPs mixed with the radionuclide {sup 68}Ga enabled superior sensitivity compared with the radionuclide {sup 68}Ga only, with 50-fold improvement on detection sensitivity, which guaranteed meeting the demands of the clinical diagnosis of gastrointestinal tract tumors.

  10. Open Principle for Large High-Resolution Solar Telescopes

    NASA Astrophysics Data System (ADS)

    Hammerschlag, Robert H.; Bettonvil, Felix C. M.; Jägers, Aswin P. L.; Sliepen, Guus

    2009-04-01

    Vacuum solar telescopes solve the problem of image deterioration inside the telescope due to refractive index fluctuations of the air heated by the solar light. However, such telescopes have a practical diameter limit somewhat over 1 m. The Dutch Open Telescope (DOT) was the pioneering demonstrator of the open-telescope technology without need of vacuum, now pursued in the German GREGOR. Important ingredients for this technology are primary beam completely open to natural wind flow, stiff but still open design by principal stiff overall geometries in combination with carefully designed joints and completely open-foldable dome constructions based on tensioned strong cloth. Further developments to large sizes are made within the framework of the design study for a European Solar Telescope (EST).

  11. Hubble Space Telescope

    NASA Technical Reports Server (NTRS)

    1990-01-01

    An overview of the mission of the Hubble Space Telescope, a joint project between NASA and the European Space Agency which will be used to study deep space, as well as our solar system is presented. The video contains animations depicting the Hubble Space Telescope in orbit, as well as footage of scientists at the Space Telescope Science Institute making real time observations. The images Hubble acquires will be downloaded into a database that contains images of over 19,000,000 celestial objects called the Star Catalog.

  12. Telescopic vision contact lens

    NASA Astrophysics Data System (ADS)

    Tremblay, Eric J.; Beer, R. Dirk; Arianpour, Ashkan; Ford, Joseph E.

    2011-03-01

    We present the concept, optical design, and first proof of principle experimental results for a telescopic contact lens intended to become a visual aid for age-related macular degeneration (AMD), providing magnification to the user without surgery or external head-mounted optics. Our contact lens optical system can provide a combination of telescopic and non-magnified vision through two independent optical paths through the contact lens. The magnified optical path incorporates a telescopic arrangement of positive and negative annular concentric reflectors to achieve 2.8x - 3x magnification on the eye, while light passing through a central clear aperture provides unmagnified vision.

  13. Multi-use lunar telescopes

    NASA Technical Reports Server (NTRS)

    Drummond, Mark; Hine, Butler; Genet, Russell; Genet, David; Talent, David; Boyd, Louis; Trueblood, Mark; Filippenko, Alexei V. (Editor)

    1991-01-01

    The objective of multi-use telescopes is to reduce the initial and operational costs of space telescopes to the point where a fair number of telescopes, a dozen or so, would be affordable. The basic approach is to develop a common telescope, control system, and power and communications subsystem that can be used with a wide variety of instrument payloads, i.e., imaging CCD cameras, photometers, spectrographs, etc. By having such a multi-use and multi-user telescope, a common practice for earth-based telescopes, development cost can be shared across many telescopes, and the telescopes can be produced in economical batches.

  14. Multi-use lunar telescopes

    NASA Technical Reports Server (NTRS)

    Genet, Russell M.; Genet, David R.; Talent, David L.; Drummond, Mark; Hine, Butler P.; Boyd, Louis J.; Trueblood, Mark

    1992-01-01

    The objective of multi-use telescopes is to reduce the initial and operational costs of space telescopes to the point where a fair number of telescopes, a dozen or so, would be affordable. The basic approach is to develop a common telescope, control system, and power and communications subsystem that can be used with a wide variety of instrument payloads, i.e., imaging CCD cameras, photometers, spectrographs, etc. By having such a multi-use and multi-user telescope, a common practice for earth-based telescopes, development cost can be shared across many telescopes, and the telescopes can be produced in economical batches.

  15. Webb Telescope: Planetary Evolution

    NASA Video Gallery

    Stars and planets form in the dark, inside vast, cold clouds of gas and dust. The James Webb Space Telescope's large mirror and infrared sensitivity will let astronomers peer inside dusty knots whe...

  16. Holographic telescope arrays.

    PubMed

    Lohmann, A W; Sauer, F

    1988-07-15

    A typical job in optical computing is to illuminate an array of small nonlinear optical components, separated by wide gaps to avoid crosstalk. We do this by letting a wide uniform beam fall onto a densely packed array of minifying telescopes. Each telescope produces a narrow bundle of parallel rays which illuminates one of the nonlinear optical components. The holographic telescopes can do more than change the width of the bundles of parallel rays. Their image forming capability allows the transmission of many pixels per channel in parallel. The pair of lenslets of a single holographic telescope (Kepler or Galilean) is produced in rigid coupling. The monolithic production avoids adjusting the two lenslets later on.

  17. Next Generation Space Telescope

    NASA Technical Reports Server (NTRS)

    Mather, John; Stockman, H. S.; Fisher, Richard R. (Technical Monitor)

    2000-01-01

    The Next Generation Space Telescope (NGST), planned for launch in 2009, will be an 8-m class radiatively cooled infrared telescope at the Lagrange point L2. It will cover the wavelength range from 0.6 to 28 microns with cameras and spectrometers, to observe the first luminous objects after the Big Bang, and the formation, growth, clustering, and evolution of galaxies, stars, and protoplanetary clouds, leading to better understanding of our own Origins. It will seek evidence of the cosmic dark matter through its gravitational effects. With an aperture three times greater than the Hubble Space Telescope, it will provide extraordinary advances in capabilities and enable the discovery of many new phenomena. It is a joint project of the NASA, ESA, and CSA, and scientific operations will be provided by the Space Telescope Science Institute.

  18. Telescopes and space exploration

    NASA Technical Reports Server (NTRS)

    Brandt, J. C.; Maran, S. P.

    1982-01-01

    Progress in contemporary astronomy and astrophysics is shown to depend on complementary investigations with sensitive telescopes operating in several wavelength regions, some of which can be on the Earth's surface and others of which must be in space.

  19. Hubble Space Telescope Assembly

    NASA Technical Reports Server (NTRS)

    1986-01-01

    This photograph shows the Hubble Space Telescope (HST) flight article assembly with multilayer insulation, high gain anterna, and solar arrays in a clean room of the Lockheed Missile and Space Company. The HST is the first of NASA's great observatories and the most complex and sensitive optical telescope ever made. The purpose of the HST is to study the cosmos from a low-Earth orbit by placing the telescope in space, enabling astronomers to collect data that is free of the Earth's atmosphere. The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had overall responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Connecticut, developed the optical system and guidance sensors. The Lockheed Missile and Space Company, Sunnyvale, California, produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope.

  20. Composite Space Telescope Truss

    NASA Video Gallery

    NASA engineers are recycling an idea for a lightweight, compact space telescope structure from the early 1990s. The 315 struts and 84 nodes were originally designed to enable spacewalking astronaut...

  1. Large Binocular Telescope Project

    NASA Astrophysics Data System (ADS)

    Hill, John M.

    1997-03-01

    The large binocular telescope (LBT) project have evolved from concepts first proposed in 1985. The present partners involved in the design and construction of this 2 by 8.4 meter binocular telescope are the University of Arizona, Italy represented by the Osservatorio Astrofisico di Arcetri and the Research Corporation based in Tucson, Arizona. These three partners have committed sufficient funds to build the enclosure and the telescope populated with a single 8.4 meter optical train -- approximately 40 million dollars (1989). Based on this commitment, design and construction activities are now moving forward. Additional partners are being sought. The next mirror to be cast at the Steward Observatory Mirror Lab in the fall of 1996 will be the first borosilicate honeycomb primary for LBT. The baseline optical configuration of LBT includes wide field Cassegrain secondaries with optical foci above the primaries to provide a corrected one degree field at F/4. The infrared F/15 secondaries are a Gregorian design to allow maximum flexibility for adaptive optics. The F/15 secondaries are undersized to provide a low thermal background focal plane which is unvignetted over a 4 arcminute diameter field-of-view. The interferometric focus combining the light from the two 8.4 meter primaries will reimage two folded Gregorian focal planes to a central location. The telescope elevation structure accommodates swing arms which allow rapid interchange of the various secondary and tertiary mirrors. Maximum stiffness and minimal thermal disturbance continue to be important drivers for the detailed design of the telescope. The telescope structure accommodates installation of a vacuum bell jar for aluminizing the primary mirrors in-situ on the telescope. The detailed design of the telescope structure will be completed in 1996 by ADS Italia (Lecco) and European Industrial Engineering (Mestre). The final enclosure design is now in progress at M3 Engineering (Tucson), EIE and ADS Italia

  2. Heinrich Hertz Telescope

    NASA Astrophysics Data System (ADS)

    Baars, Jacob W.; Martin, Robert N.

    1998-07-01

    The Heinrich Hertz Telescope is a radio telescope dedicated to the observation of submillimeter wavelength radiation from celestial sources. It is a Cassegrain telescope with a diameter of 10 m and a reflector accuracy of about 17 micrometer, yielding an excellent performance at 350 micrometer, the shortest wavelength transmitted through the atmosphere. The reflector panels and the backup structure employ carbon-fiber reinforced plastic as basic material to achieve a lightweight, stiff construction with a very small coefficient of thermal expansion. This enables us to maintain full performance of the telescope in day time under solar illumination of the structure. In this paper, we describe the structural and material characteristics of the telescope. We also describe the holographic method which enables a measurement and setting of the reflector panels to an accuracy of 10 micrometer. The telescope is located on Mt. Graham in Eastern Arizona at an altitude of 3250 m, providing good submillimeter observing conditions, especially in the winter months. This is a collaborative effort of the Max-Planck- Institut fur Radioastronomie, Bonn, Germany and Steward Observatory, University of Arizona, Tucson, AZ.

  3. NST: Thermal Modeling for a Large Aperture Solar Telescope

    NASA Astrophysics Data System (ADS)

    Coulter, Roy

    2011-05-01

    Late in the 1990s the Dutch Open Telescope demonstrated that internal seeing in open, large aperture solar telescopes can be controlled by flushing air across the primary mirror and other telescope structures exposed to sunlight. In that system natural wind provides a uniform air temperature throughout the imaging volume, while efficiently sweeping heated air away from the optics and mechanical structure. Big Bear Solar Observatory's New Solar Telescope (NST) was designed to realize that same performance in an enclosed system by using both natural wind through the dome and forced air circulation around the primary mirror to provide the uniform air temperatures required within the telescope volume. The NST is housed in a conventional, ventilated dome with a circular opening, in place of the standard dome slit, that allows sunlight to fall only on an aperture stop and the primary mirror. The primary mirror is housed deep inside a cylindrical cell with only minimal openings in the side at the level of the mirror. To date, the forced air and cooling systems designed for the NST primary mirror have not been implemented, yet the telescope regularly produces solar images indicative of the absence of mirror seeing. Computational Fluid Dynamics (CFD) analysis of the NST primary mirror system along with measurements of air flows within the dome, around the telescope structure, and internal to the mirror cell are used to explain the origin of this seemingly incongruent result. The CFD analysis is also extended to hypothetical systems of various scales. We will discuss the results of these investigations.

  4. The Multiple-Mirror Telescope

    ERIC Educational Resources Information Center

    Carleton, Nathaniel P.; Hoffmann, William F.

    1978-01-01

    Describes the basic design and principle of operating an optical-infrared telescope, the MMT. This third largest telescope in the world represents a new stage in telescope design; it uses a cluster of six reflecting telescopes, and relies on an automatic sensing and control system. (GA)

  5. Mechanical design of the solar telescope GREGOR

    NASA Astrophysics Data System (ADS)

    Volkmer, R.; Eisenträger, P.; Emde, P.; Fischer, A.; von der Lühe, O.; Nicklas, H.; Soltau, D.; Schmidt, W.; Weis, U.

    2012-11-01

    The mechanical structure of the GREGOR telescope was installed at the Observatorio del Teide, Tenerife, in 2004. New concepts for mounting and cooling of the 1.5-meter primary mirror were introduced. GREGOR is an open telescope, therefore the dome is completely open during observations to allow for air flushing through the open, but stiff telescope structure. Backside cooling system of the primary mirror keeps the mirror surface close to ambient temperature to prevent mirror seeing. The large collecting area of the primary mirror results in high energy density at the field stop at the prime focus of the primary which needs to be removed. The optical elements are supported by precision alignment systems and should provide a stable solar image at the optical lab. The coudé train can be evacuated and serves as a natural barrier between the outer environmental conditions and the air-conditioned optical laboratory with its sensitive scientific instrumentation. The telescope was successfully commissioned and will start its nominal operation during 2013.

  6. Antarctic radio Askaryan neutrino telescopes

    NASA Astrophysics Data System (ADS)

    Connolly, Amy

    2012-03-01

    There are strong motivations for a detectable flux of ultra-high energy (UHE) cosmic neutrinos above 10^17-18 eV. Neutrinos in this regime are expected from interactions between the highest energy cosmic rays and cosmic microwave background photons, and can also originate from the UHE sources themselves. Radio Cerenkov technique is the most promising technique for instrumenting a detection volume large enough to detect the low expected fluxes. The RICE experiment pioneered the radio Cerenkov technique with antennas deployed along strings of the AMANDA experiment deep in the South Pole ice. New radio arrays being deployed in the Antarctic ice are designed to measure dozens of these unique cosmic messengers to exploit the rich particle physics and astrophysical information that they carry. I will discuss the status and results from initial deployments of the Askaryan Radio Array (ARA) near the South Pole, and the ARIANNA array on the Ross Ice Shelf. I will also describe how these experiments could measure neutrino-nucleon cross sections at energies that exceed those probed by the LHC.

  7. Telescopes in education

    NASA Astrophysics Data System (ADS)

    Yessayian, Rick

    Imagine sitting in your classroom with your students and controlling a Research Grade 24 inch telescope. You control where it points, you control the duration of the exposure of a high grade CCD camera, and you control all of this within your school day, on a camera half way around the globe, in real time. You can hear the telescope moving, talk to the operator sitting atop historic Mt. Wilson Observatory in California. You might be looking at comets, asteroids, galaxies, nebulas or a host of other interesting celestial objects. Perhaps you have students that are up to a real challenge -- doing real science! Students in our program have contributed the discovery of a new variable star, to the Pluto Express project, to the search for supernovas, and the collection of images of intersecting galaxies. These are among the many possible projects you might choose from. The age and ability of your students are taken into account when you choose your project. Students from Kindergarten through Grade 12 have participated in this free program. A new robotic telescope was added at Mount Wilson in 1999. The telescope is a Celestron 14" SCT mounted on a Bisque Paramount GT-1100 with an Apogee AP-7 CCD camera (512X512 pixels). In the Spring of 2001, we duplicated the 14" robotic telescope configuration and placed it at the Las Campanas Observatory, Chile (operated by the Carnegie Observatories). I installed the system in late September, 2001, and we began testing. The system requires one more upgrade and some hardware adjustments, which I will complete in June, 2002. We duplicated another 14" robotic telescope, and sent it to Brisbane Australia in January, 2002. The grand opening of the telescope will be in August 2002.

  8. Monolithic afocal telescope

    NASA Technical Reports Server (NTRS)

    Roberts, William T. (Inventor)

    2010-01-01

    An afocal monolithic optical element formed of a shallow cylinder of optical material (glass, polymer, etc.) with fast aspheric surfaces, nominally confocal paraboloids, configured on the front and back surfaces. The front surface is substantially planar, and this lends itself to deposition of multi-layer stacks of thin dielectric and metal films to create a filter for rejecting out-of-band light. However, an aspheric section (for example, a paraboloid) can either be ground into a small area of this surface (for a Cassegrain-type telescope) or attached to the planar surface (for a Gregorian-type telescope). This aspheric section of the surface is then silvered to create the telescope's secondary mirror. The rear surface of the cylinder is figured into a steep, convex asphere (again, a paraboloid in the examples), and also made reflective to form the telescope's primary mirror. A small section of the rear surface (approximately the size of the secondary obscuration, depending on the required field of the telescope) is ground flat to provide an unpowered surface through which the collimated light beam can exit the optical element. This portion of the rear surface is made to transmit the light concentrated by the reflective surfaces, and can support the deposition of a spectral filter.

  9. Spectroradiometry with space telescopes

    NASA Astrophysics Data System (ADS)

    Pauluhn, Anuschka; Huber, Martin C. E.; Smith, Peter L.; Colina, Luis

    2015-12-01

    Radiometry, i.e. measuring the power of electromagnetic radiation—hitherto often referred to as "photometry"—is of fundamental importance in astronomy. We provide an overview of how to achieve a valid laboratory calibration of space telescopes and discuss ways to reliably extend this calibration to the spectroscopic telescope's performance in space. A lot of effort has been, and still is going into radiometric "calibration" of telescopes once they are in space; these methods use celestial primary and transfer standards and are based in part on stellar models. The history of the calibration of the Hubble Space Telescope serves as a platform to review these methods. However, we insist that a true calibration of spectroscopic space telescopes must directly be based on and traceable to laboratory standards, and thus be independent of the observations. This has recently become a well-supported aim, following the discovery of the acceleration of the cosmic expansion by use of type-Ia supernovae, and has led to plans for launching calibration rockets for the visible and infrared spectral range. This is timely, too, because an adequate exploitation of data from present space missions, such as Gaia, and from many current astronomical projects like Euclid and WFIRST demands higher radiometric accuracy than is generally available today. A survey of the calibration of instruments observing from the X-ray to the infrared spectral domains that include instrument- or mission-specific estimates of radiometric accuracies rounds off this review.

  10. Towers for Antarctic Telescopes

    NASA Astrophysics Data System (ADS)

    Hammerschlag, R. H.; Bettonvil, F. C. M.; Jägers, A. P. L.; Nielsen, G.

    To take advantage of the exceptional seeing above the boundary layer on Antarctic sites, a high-resolution telescope must be mounted on a support tower. An open transparent tower of framework minimizes the upward temperature-disturbed airflow. A typical minimum height is 30m. The tower platform has to be extremely stable against wind-induced rotational motions, which have to be less than fractions of an arc second, unusually small from a mechanical engineering viewpoint. In a traditional structure, structural deflections result in angular deflections of the telescope platform, which introduce tip and tilt motions in the telescope. However, a structure that is designed to deflect with parallel motion relative to the horizontal plane will undergo solely translation deflections in the telescope platform and thus will not degrade the image. The use of a parallel motion structure has been effectively demonstrated in the design of the 15-m tower for the Dutch Open Telescope (DOT) on La Palma. Special framework geometries are developed, which make it possible to construct high towers in stories having platforms with extreme stability against wind-induced tilt. These geometric solutions lead to constructions, being no more massive than a normal steel framework carrying the same load. Consequently, these lightweight towers are well suited to difficult sites as on Antarctica. A geometry with 4 stories has been worked out.

  11. The Travelling Telescope

    NASA Astrophysics Data System (ADS)

    Murabona Oduori, Susan

    2015-08-01

    The telescope has been around for more than 400 years, and through good use of it scientists have made many astonishing discoveries and begun to understand our place in the universe. Most people, however, have never looked through one. Yet it is a great tool for cool science and observation especially in a continent and country with beautifully dark skies. The Travelling Telescope project aims to invite people outside under the stars to learn about those curious lights in the sky.The Travelling Telescope aims to promote science learning to a wide range of Kenyan schools in various locations exchanging knowledge about the sky through direct observations of celestial bodies using state of the art telescopes. In addition to direct observing we also teach science using various hands-on activities and astronomy software, ideal for explaining concepts which are hard to understand, and for a better grasp of the sights visible through the telescope. We are dedicated to promoting science using astronomy especially in schools, targeting children from as young as 3 years to the youth, teachers, their parents and members of the public. Our presentation focuses on the OAD funded project in rural coastal Kenya.

  12. Robotic and Survey Telescopes

    NASA Astrophysics Data System (ADS)

    Woźniak, Przemysław

    Robotic telescopes are revolutionizing the way astronomers collect their dataand conduct sky surveys. This chapter begins with a discussion of principles thatguide the process of designing, constructing, and operating telescopes andobservatories that offer a varying degree of automation, from instruments remotelycontrolled by observers to fully autonomous systems requiring no humansupervision during their normal operations. Emphasis is placed on designtrade-offs involved in building end-to-end systems intended for a wide range ofscience applications. The second part of the chapter contains descriptions ofseveral projects and instruments, both existing and currently under development.It is an attempt to provide a representative selection of actual systems thatillustrates state of the art in technology, as well as important ideas and milestonesin the development of the field. The list of presented instruments spans the fullrange in size starting from small all-sky monitors, through midrange robotic andsurvey telescopes, and finishing with large robotic instruments and surveys.Explosive growth of telescope networking is enabling entirely new modesof interaction between the survey and follow-up observing. Increasingimportance of standardized communication protocols and software is stressed.These developments are driven by the fusion of robotic telescope hardware,massive storage and databases, real-time knowledge extraction, and datacross-correlation on a global scale. The chapter concludes with examplesof major science results enabled by these new technologies and futureprospects.

  13. The South Pole Telescope

    SciTech Connect

    Ruhl, J.E.; Ade, P.A.R.; Carlstrom, J.E.; Cho, H.M.; Crawford,T.; Dobbs, M.; Greer, C.H.; Halverson, N.W.; Holzapfel, W.L.; Lanting,T.M.; Lee, A.T.; Leitch, E.M.; Leong, J.; Lu, W.; Lueker, M.; Mehl, J.; Meyer, S.S.; Mohr, J.J.; Padin, S.; Plagge, T.; Pryke, C.; Runyan, M.C.; Schwan, D.; Sharp, M.K.; Spieler, H.; Staniszewski, Z.; Stark, A.A.

    2004-11-04

    A new 10 meter diameter telescope is being constructed for deployment at the NSF South Pole research station. The telescope is designed for conducting large-area millimeter and sub-millimeter wave surveys of faint, low contrast emission, as required to map primary and secondary anisotropies in the cosmic microwave background. To achieve the required sensitivity and resolution, the telescope design employs an off-axis primary with a 10 m diameter clear aperture. The full aperture and the associated optics will have a combined surface accuracy of better than 20 microns rms to allow precision operation in the submillimeter atmospheric windows. The telescope will be surrounded with a large reflecting ground screen to reduce sensitivity to thermal emission from the ground and local interference. The optics of the telescope will support a square degree field of view at 2mm wavelength and will feed a new 1000-element micro-lithographed planar bolometric array with superconducting transition-edge sensors and frequency-multiplexed readouts. The first key project will be to conduct a survey over 4000 degrees for galaxy clusters using the Sunyaev-Zeldovich Effect. This survey should find many thousands of clusters with a mass selection criteria that is remarkably uniform with redshift. Armed with redshifts obtained from optical and infrared follow-up observations, it is expected that the survey will enable significant constraints to be placed on the equation of state of the dark energy.

  14. The Nuclear Compton Telescope

    NASA Astrophysics Data System (ADS)

    Boggs, Steven E.; NCT Collaboration

    2011-09-01

    The Nuclear Compton Telescope (NCT) is a balloon-borne soft gamma-ray (0.2-10 MeV) telescope designed to perform wide-field imaging, high-resolution spectroscopy, and novel polarization analysis of astrophysical sources. NCT employs a novel Compton telescope design, utilizing 12 high spectral resolution germanium detectors, with the ability to localize photon interaction in three dimensions. NCT underwent its first science flight from Fort Sumner, NM in Spring 2009, and was partially destroyed during a second launch attempt from Alice Spring, Australia in Spring 2010. We will present an overview of the NCT program, including results from the Spring 2009 flight, as well as status and plans for the NCT program.

  15. Configurable Aperture Space Telescope

    NASA Technical Reports Server (NTRS)

    Ennico, Kimberly; Vassigh, Kenny; Bendek, Selman; Young, Zion W; Lynch, Dana H.

    2015-01-01

    In December 2014, we were awarded Center Innovation Fund to evaluate an optical and mechanical concept for a novel implementation of a segmented telescope based on modular, interconnected small sats (satlets). The concept is called CAST, a Configurable Aperture Space Telescope. With a current TRL is 2 we will aim to reach TLR 3 in Sept 2015 by demonstrating a 2x2 mirror system to validate our optical model and error budget, provide strawman mechanical architecture and structural damping analyses, and derive future satlet-based observatory performance requirements. CAST provides an alternative access to visible andor UV wavelength space telescope with 1-meter or larger aperture for NASA SMD Astrophysics and Planetary Science community after the retirement of HST.

  16. Configurable Aperture Space Telescope

    NASA Technical Reports Server (NTRS)

    Ennico, Kimberly; Bendek, Eduardo

    2015-01-01

    In December 2014, we were awarded Center Innovation Fund to evaluate an optical and mechanical concept for a novel implementation of a segmented telescope based on modular, interconnected small sats (satlets). The concept is called CAST, a Configurable Aperture Space Telescope. With a current TRL is 2 we will aim to reach TLR 3 in Sept 2015 by demonstrating a 2x2 mirror system to validate our optical model and error budget, provide straw man mechanical architecture and structural damping analyses, and derive future satlet-based observatory performance requirements. CAST provides an alternative access to visible and/or UV wavelength space telescope with 1-meter or larger aperture for NASA SMD Astrophysics and Planetary Science community after the retirement of HST

  17. LSST telescope modeling overview

    NASA Astrophysics Data System (ADS)

    Sebag, J.; Andrew, J.; Angeli, G.; Araujo, C.; Barr, J.; Callahan, S.; Cho, M.; Claver, C.; Daruich, F.; Gressler, W.; Hileman, E.; Liang, M.; Muller, G.; Neill, D.; Schoening, W.; Warner, M.; Wiecha, O.; Xin, B.; Orden Martinez, Alfredo; Perezagua Aguado, Manuel; García Marchena, Luis; Ruiz de Argandoña, Ismael

    2016-08-01

    During this early stage of construction of the Large Synoptic Survey Telescope (LSST), modeling has become a crucial system engineering process to ensure that the final detailed design of all the sub-systems that compose the telescope meet requirements and interfaces. Modeling includes multiple tools and types of analyses that are performed to address specific technical issues. Three-dimensional (3D) Computeraided Design (CAD) modeling has become central for controlling interfaces between subsystems and identifying potential interferences. The LSST Telescope dynamic requirements are challenging because of the nature of the LSST survey which requires a high cadence of rapid slews and short settling times. The combination of finite element methods (FEM), coupled with control system dynamic analysis, provides a method to validate these specifications. An overview of these modeling activities is reported in this paper including specific cases that illustrate its impact.

  18. Ultrathin zoom telescopic objective.

    PubMed

    Li, Lei; Wang, Di; Liu, Chao; Wang, Qiong-Hua

    2016-08-08

    We report an ultrathin zoom telescopic objective that can achieve continuous zoom change and has reduced compact volume. The objective consists of an annular folded lens and three electrowetting liquid lenses. The annular folded lens undertakes the main part of the focal power of the lens system. Due to a multiple-fold design, the optical path is folded in a lens with the thickness of ~1.98mm. The electrowetting liquid lenses constitute a zoom part. Based on the proposed objective, an ultrathin zoom telescopic camera is demonstrated. We analyze the properties of the proposed objective. The aperture of the proposed objective is ~15mm. The total length of the system is ~18mm with a tunable focal length ~48mm to ~65mm. Compared with the conventional zoom telescopic objective, the total length has been largely reduced.

  19. The Discovery Channel Telescope

    NASA Astrophysics Data System (ADS)

    Millis, R. L.; Dunham, E. W.; Sebring, T. A.; Smith, B. W.; de Kock, M.; Wiecha, O.

    2004-11-01

    The Discovery Channel Telescope (DCT) is a 4.2-m telescope to be built at a new site near Happy Jack, Arizona. The DCT features a large prime focus mosaic CCD camera with a 2-degree-diameter field of view especially designed for surveys of KBOs, Centaurs, NEAs and other moving or time-variable targets. The telescope can be switched quickly to a Ritchey-Chretien configuration for optical/IR spectroscopy or near-IR imaging. This flexibility allows timely follow-up physical studies of high priority objects discovered in survey mode. The ULE (ultra-low-expansion) meniscus primary and secondary mirror blanks for the telescope are currently in fabrication by Corning Glass. Goodrich Aerospace, Vertex RSI, M3 Engineering and Technology Corp., and e2v Technologies have recently completed in-depth conceptual design studies of the optics, mount, enclosure, and mosaic focal plane, respectively. The results of these studies were subjected to a formal design review in July, 2004. Site testing at the 7760-ft altitude Happy Jack site began in 2001. Differential image motion observations from 117 nights since January 1, 2003 gave median seeing of 0.84 arcsec FWHM, and the average of the first quartile was 0.62 arcsec. The National Environmental Policy Act (NEPA) process for securing long-term access to this site on the Coconino National Forest is nearing completion and ground breaking is expected in the spring of 2005. The Discovery Channel Telescope is a project of the Lowell Observatory with major financial support from Discovery Communications, Inc. (DCI). DCI plans ongoing television programming featuring the construction of the telescope and the research ultimately undertaken with the DCT. An additional partner can be accommodated in the project. Interested parties should contact the lead author.

  20. The ANTARES neutrino telescope

    NASA Astrophysics Data System (ADS)

    Distefano, Carla

    The ANTARES collaboration has completed in 2008 the construction of an underwater high-energy neutrino telescope in the Mediterranean Sea, located 40 km off the French coast at a depth of 2500 m. The detector consists of 885 optical modules, which are distributed in 12 detector lines, various calibration systems and devices for environmental measurements. With an instrumented volume of about 0.05 km3, ANTARES is the largest Cherenkov neutrino detector currently operating in the Northern hemisphere. A general overview on the ANTARES telescope is given. The preliminary results from the various physics analyses on the collected data will be presented.

  1. Present status of very high energy gamma ray astronomy and plans for an imaging gamma ray telescope in India

    NASA Astrophysics Data System (ADS)

    Bhat, C. L.

    1993-09-01

    The unequivocal detection of the Crab Nebula as the first-ever standard candle in the very high energy (VHE) bracket, made possible by the recently-developed Cerenkov Imaging Technique, marks a water-shed in the 20 year-old history of the TeV gamma-ray astronomy. It gives hope that, as with the Crab today, future detections in the field, too, will be on a firm statistical footing and the attendant investigations, more comprehensive in their content and range. The present mood in the field is one of cautious optimism. This paper gives an overview of the contemporary observational scene in the ground-based gamma-ray astronomy. It closes with an introduction to TACTIC, the first Indian Imaging gamma-ray telescope, presently under-development.

  2. SU-E-T-108: An Investigation of Cerenkov Light Production in the Exradin W1 Scintillator Under Various Measurement Conditions

    SciTech Connect

    Simiele, E; Culberson, W

    2015-06-15

    Purpose: To investigate the effects of depth, fiber-optic cable bends, and incident radiation angle on Cerenkov production in the Standard Imaging Exradin W1. Methods: Measurements were completed using a Varian Clinac 21EX linear accelerator with an Exradin W1 scintillator as well as a cable-only scintillator (no scintillation material) to isolate the Cerenkov signal. The effects of cable bend radius and location were investigated by bending the fiber-optic cable into a circle with radii ranging from 1.0 to 10.8 cm and positioning the center of the coil at distances ranging from 10.0 to 175.0 cm from the photodiode. The effects of depth and incident radiation angle were investigated by performing measurements in water at depths ranging from 1.0 cm to 25.0 cm and angles ranging from 0° to 80°. Eclipse treatment-planning software was utilized to ensure a consistent dose was delivered to the W1 regardless of depth or angle. Results: Measured signal in both channels of the cable-only scintillator decreased as the bend radius decreased and as the distance between the bend and photodiode increased. A fiber bend of 1.0 cm radius produced a 17.1% decrease in the green channel response in the cable-only scintillator. The effect of depth was less severe; a maximum increase of 6.6% in the green channel response was observed at a depth of 25.0 cm in the W1. In the angular dependence investigation, the signal in both channels of the W1 peaked at an angle of 40°; which is in agreement with the nominal Cerenkov emission angle of 45°. Conclusion: The green channel response in the W1 (mainly Cerenkov signal) varied with depth, fiber-optic cable bends, and incident radiation angle. Fully characterizing Cerenkov production is essential to ensure it is properly accounted for in scintillator measurements. Research funding and materials received by Standard Imaging, Inc. (Middleton WI)

  3. Apollo Telescope Mount Illustration

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The Apollo Telescope Mount (ATM) served as the first marned astronomical observatory in space. It was designed for solar research from Earth orbit aboard the Skylab. This image is a cutaway illustration of the ATM canister with callouts and characteristics. The ATM was designed and developed by the Marshall Space Flight Center.

  4. Apollo Telescope Mount Illustration

    NASA Technical Reports Server (NTRS)

    1971-01-01

    The Apollo Telescope Mount (ATM) served as the first marned astronomical observatory in space. It was designed for solar research from Earth orbit aboard the Skylab. This image is a cutaway illustration of the ATM canister. The ATM was designed and developed by the Marshall Space Flight Center.

  5. Apollo Telescope Mount Illustration

    NASA Technical Reports Server (NTRS)

    1971-01-01

    The Apollo Telescope Mount (ATM) served as the first marned astronomical observatory in space. It was designed for solar research from Earth orbit aboard the Skylab. This image is a cutaway illustration of the ATM canister with callouts. The ATM was designed and developed by the Marshall Space Flight Center.

  6. A Simple "Tubeless" Telescope

    ERIC Educational Resources Information Center

    Straulino, S.; Bonechi, L.

    2010-01-01

    Two lenses make it possible to create a simple telescope with quite large magnification. The set-up is very simple and can be reproduced in schools, provided the laboratory has a range of lenses with different focal lengths. In this article, the authors adopt the Keplerian configuration, which is composed of two converging lenses. This instrument,…

  7. Exploring Galileo's Telescope

    ERIC Educational Resources Information Center

    Straulino, Samuele; Terzuoli, Alessandra

    2010-01-01

    In the first months of 2009, the International Year of Astronomy, the authors developed an educational project for middle-level students connected with the first astronomical discoveries that Galileo Galilei (1564-1642) made 400 years ago. The project included the construction of a basic telescope and the observation of the Moon. The project, if…

  8. The Liverpool Telescope

    NASA Astrophysics Data System (ADS)

    Smith, Robert J.; Bates, S. D.; Clay, Neil R.; Fraser, Stephen N.; Marchant, J. M.; Mottram, C. J.; Steele, I. A.; Tomlinson, M. D.

    2011-03-01

    The Liverpool Telescope (LT) is a fully robotic 2m optical telescope at a world-class observatory site. It runs autonomously without direct human control either on site or remotely. It is not operated primarily for a single science project, but rather is a common-user facility, time allocated by an open, peer-review process and conducting a variety of optical and IR imaging, spectroscopic and polarimetric programs. This paper describes some of aspects of the site infrastructure and instrument suite designed specifically to support robust and reliable unsupervised operations. Aside from the telescope hardware, the other aspect of robotic operations is the mechanisms whereby users interact with the telescope and its automated scheduler. We describe how these have been implemented for the LT. Observing routinely since 2004, the LT has demonstrated it is possible to operate a large, common-user robotic observatory. Making the most of the flexibility afforded by fully robotic operations, development continues in collaboration with both observers and other observatories to develop observing modes to enable new science across the broad discipline of time-domain astrophysics.

  9. Wearable telescopic contact lens.

    PubMed

    Arianpour, Ashkan; Schuster, Glenn M; Tremblay, Eric J; Stamenov, Igor; Groisman, Alex; Legerton, Jerry; Meyers, William; Amigo, Goretty Alonso; Ford, Joseph E

    2015-08-20

    We describe the design, fabrication, and testing of a 1.6 mm thick scleral contact lens providing both 1× and 2.8× magnified vision paths, intended for use as a switchable eye-borne telescopic low-vision aid. The F/9.7 telescopic vision path uses an 8.2 mm diameter annular entrance pupil and 4 internal reflections in a polymethyl methacrylate precision optic. This gas-impermeable insert is contained inside a smooth outer casing of rigid gas-permeable polymer, which also provides achromatic correction for refraction at the curved lens face. The unmagnified F/4.1 vision path is through the central aperture of the lens, with additional transmission between the annular telescope rings to enable peripheral vision. We discuss potential solutions for providing oxygenation for an extended wear version of the lens. The prototype lenses were characterized using a scale-model human eye, and telescope functionality was confirmed in a small-scale clinical (nondispensed) demonstration.

  10. Hubble Space Telescope Assembly

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Engineers and technicians conduct a fit check of the Hubble Space Telescope (HST) Solar Array flight article in a clean room of the Lockheed Missile and Space Company. The Solar Array is 40- feet (12.1-meters) long and 8.2-feet (2.5-meters) wide, and provides power to the spacecraft. The HST is the first of NASA's great observatories and the most complex and sensitive optical telescope ever made. The purpose of the HST is to study the cosmos from a low-Earth orbit by placing the telescope in space, enabling astronomers to collect data that is free of the Earth's atmosphere. The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had overall responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Cornecticut, developed the optical system and guidance sensors. The Lockheed Missile and Space Company, Sunnyvale, California, produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope.

  11. Membrane photon sieve telescopes.

    PubMed

    Andersen, Geoff

    2010-11-20

    We present results of research into the design and construction of membrane photon sieves as primaries for next-generation lightweight space telescopes. We have created prototypes in electroformed nickel as well as diazo and CP-1 polymer films. In two such cases, diffraction-limited imaging performance was demonstrated over a narrow bandwidth.

  12. A Novel Dust Telescope

    NASA Astrophysics Data System (ADS)

    Grün, E.; Srama, R.; Krüger, H.; Kempf, S.; Harris, D.; Conlon, T.; Auer, S.

    2001-11-01

    Dust particles in space, like photons, are born at remote sites in space and time. From knowledge of the dust particles' birthplace and the particles' bulk properties, we can learn about the remote environment out of which the particles were formed. This approach is carried out by means of a dust telescope on a dust observatory in space. A dust telescope is a combination of a dust trajectory sensor together with a chemical composition analyzer for dust particles. A novel dust telescope is described. It consists of a highly sensitive dust trajectory sensor, and a large area chemical dust analyzer. It can provide valuable information about the particles' birthplace which may not be accessible by other techniques. Dust particles' trajectories are determined by the measurement of the electric signals that are induced when a charged grain flies through an appropriately configured electrode systems. After the successful identification of a few charged micron-sized dust grains in space by the Cassini Cosmic Dust Analyzer, this dust telescope has a ten fold increased sensitivity of charge detection (10-16 Coulombs) and will be able to obtain trajectories for sub-micron sized dust grains. State-of-the art dust chemical analyzers have sufficient mass resolution to resolve ions with atomic mass numbers above 100. However, since their impact areas are small they can analyze statistically meaningful numbers of grains only in the dust-rich environments of comets or ringed planets. Therefore, this dust telescope includes a large area (0.1 m2) chemical dust analyzer of mass resolution > 100 that will allow us to obtain statistically significant measurements of interplanetary and interstellar dust grains in space.

  13. Giant Magellan Telescope: overview

    NASA Astrophysics Data System (ADS)

    Johns, Matt; McCarthy, Patrick; Raybould, Keith; Bouchez, Antonin; Farahani, Arash; Filgueira, Jose; Jacoby, George; Shectman, Steve; Sheehan, Michael

    2012-09-01

    The Giant Magellan Telescope (GMT) is a 25-meter optical/infrared extremely large telescope that is being built by an international consortium of universities and research institutions. It will be located at the Las Campanas Observatory, Chile. The GMT primary mirror consists of seven 8.4-m borosilicate honeycomb mirror segments made at the Steward Observatory Mirror Lab (SOML). Six identical off-axis segments and one on-axis segment are arranged on a single nearly-paraboloidal parent surface having an overall focal ratio of f/0.7. The fabrication, testing and verification procedures required to produce the closely-matched off-axis mirror segments were developed during the production of the first mirror. Production of the second and third off-axis segments is underway. GMT incorporates a seven-segment Gregorian adaptive secondary to implement three modes of adaptive-optics operation: natural-guide star AO, laser-tomography AO, and ground-layer AO. A wide-field corrector/ADC is available for use in seeing-limited mode over a 20-arcmin diameter field of view. Up to seven instruments can be mounted simultaneously on the telescope in a large Gregorian Instrument Rotator. Conceptual design studies were completed for six AO and seeing-limited instruments, plus a multi-object fiber feed, and a roadmap for phased deployment of the GMT instrument suite is being developed. The partner institutions have made firm commitments for approximately 45% of the funds required to build the telescope. Project Office efforts are currently focused on advancing the telescope and enclosure design in preparation for subsystem- and system-level preliminary design reviews which are scheduled to be completed in the first half of 2013.

  14. The coherent Cerenkov radiated power from a group of field-aligned test particles in a magnetoplasma

    NASA Technical Reports Server (NTRS)

    Farrell, W. M.; Goertz, C. K.

    1990-01-01

    An expression is derived that describes the coherent Cerenkov radiated power from a group of test particles in a plasma medium moving parallel to a magnetic field. In this analysis, each particle has an arbitrary position and velocity along a field line and, as a consequence, both the spatial and temporal coherence of the radiation are considered. As an example, it is demonstrated that a monoenergetic electron beam consisting of small pulses can generate wave powers well above incoherent levels if the pulse spacing is comparable to an integer number of emission wavelengths. It is also shown that, if the beam particles have a velocity spread, Delta-V, the wave powers will decrease in time due to the reduced temporal coherence of the particle radiators, where this coherence scales as 1/Delta-V. This latter effect applies to any charged particle beam propagating in a magnetoplasma, because even an initially monoenergetic beam becomes thermalized by electrostatic wave-particle interactions reducing the radiated power.

  15. Simulation of a gigawatt level Ku-band overmoded Cerenkov type oscillator operated at low guiding magnetic field

    SciTech Connect

    Zhang, Hua; Shu, Ting Ju, Jinchuan; Wu, Dapeng

    2014-03-15

    We present the simulation results of a Ku-band overmoded Cerenkov type high power microwave oscillator. A guiding magnetic field as low as 0.6 T has been operated in the device. Overmoded slow wave structures with gradually tapered vanes are used in order to increase power capacity and the efficiency of beam-wave interaction. The drift cavity is adopted to enhance the beam-wave interaction of the device. After numerical optimization, the designed generator with an output microwave power of 1.2 GW, a frequency of 13.8 GHz, and a power conversion efficiency as high as 38% can be achieved, when the diode voltage and current are, respectively, 540 kV and 5.8 kA. The power compositions of TM{sub 0n} modes of the output microwave have been analyzed, the results of which show that TM{sub 01} mode takes over almost 95% of the power proportion.

  16. Wavefront Analysis of Adaptive Telescope

    NASA Technical Reports Server (NTRS)

    Hadaway, James B.; Hillman, Lloyd

    1997-01-01

    The motivation for this work came from a NASA Headquarters interest in investigating design concepts for a large space telescope employing active optics technology. The development of telescope optical requirements and potential optical design configurations is reported.

  17. Cosmology with liquid mirror telescopes

    NASA Technical Reports Server (NTRS)

    Hogg, David W.; Gibson, Brad K.; Hickson, Paul

    1993-01-01

    Liquid mirrors provide an exciting means to obtain large optical telescopes for substantially lower costs than conventional technologies. The liquid mirror concept has been demonstrated in the lab with the construction of a diffraction limited 1.5 m mirror. The mirror surface, using liquid mercury, forms a perfect parabolic shape when the mirror cell is rotated at a uniform velocity. A liquid mirror must be able to support a heavy mercury load with minimal flexure and have a fundamental resonant frequency that is as high as possible, to suppress the amplitude of surface waves caused by small vibrations transmitted to the mirror. To minimize the transmission of vibrations to the liquid surface, the entire mirror rests on an air bearing. This necessitates the mirror cell being lightweight, due to the limited load capabilities of the air bearing. The mirror components must also have physical characteristics which minimize the effects of thermal expansion with ambient temperature fluctuations in the observatory. In addition, the 2.7 m mirror construction is designed so that the techniques used may be readily extended to the construction of large mirrors. To attain the goals of a lightweight, rigid mirror, a composite laminant construction was used. The mirror consists of a foam core cut to the desired parabolic shape, with an accuracy of a few mm. An aluminum hub serves as an anchor for the foam and skin, and allows precise centering of the mirror on the air bearing and drive system. Several plys of Kevlar, covered in an epoxy matrix, are then applied to the foam. A final layer of pure epoxy is formed by spin casting. This final layer is parabolic to within a fraction of a mm. An aluminum ring bonded to the circumference of the mirror retains the mercury, and incorporates stainless-steel hard-points for the attachment of balance weights.

  18. Character of energy flow in air shower core

    NASA Technical Reports Server (NTRS)

    Mizushima, K.; Asakimori, K.; Maeda, T.; Kameda, T.; Misaki, Y.

    1985-01-01

    Energy per charged particle near the core of air showers was measured by 9 energy flow detectors, which were the combination of Cerenkov counters and scintillators. Energy per particle of each detector was normalized to energy at 2m from the core. The following results were obtained as to the energy flow: (1) integral frequency distribution of mean energy per particle (averaged over 9 detectors) is composed of two groups separated distinctly; and (2) showers contained in one group show an anisotropy of arrival direction.

  19. Uzaybimer Radio Telescope Control System

    NASA Astrophysics Data System (ADS)

    Balbay, R.; Öz, G. K.; Arslan, Ö.; Özeren, F. F.; Küçük, İ.

    2016-12-01

    A 13 meters former NATO radar is being converted into a radio telescope. The radio telescope is controlled by a system which has been developed at UZAYBİMER. The Telescope Control System(TCS) has been designed using modern industrial systems. TCS has been developed in LabView platform in which works Windows embedded OS. The position feedback used on radio telescopes is an industrial EtherCAT standard. ASCOM library is used for astronomical calculations.

  20. The Primeval Structure Telescope

    NASA Astrophysics Data System (ADS)

    Peterson, J. B.; Pen, U. L.; Wu, X. P.

    2004-12-01

    The Primeval Structure Telescope (PaST) will be used to study early ionization of the universe. The telescope will image and spectrally resolve hyperfine emission of neutral hydrogen at redshifts from about 6 to 20. Recently released data, obtained with the WMAP satellite, indicate that the universe was ionized very early, at around redshift 15. Right now, there is very little information on this ionization, since the WMAP data do not tell us the ionization history or the energy source. If the energy source was emission from collapsed objects, perhaps ultraviolet radiation from the first stars, the ionization did not occur homogenously. Earlier star formation in high-density regions causes these to be ionized first. Just when the ionization was half complete, the large-scale structure of the universe became visible in the ionization pattern. We will use redshifted 21 cm brightness to image the largest of the ionized bubbles in three dimensions, allowing us to determine the redshift of the early ionization. In addition, we will be able to study the evolution and merging of the ionized bubbles. PAST will be a sparse array telescope consisting of 10,000 log periodic antennas, providing over 50,000 square meters of effective collecting area. These antennas will be grouped into 80 phased arrays of 127 antennas. Current plans have these phased arrays fixed, pointed at the North Celestial Pole. Later, we can add electronic beam steering. Signals from the 80 phased arrays will be processed using a correlator built from a network of about 100 PC computers. The telescope will occupy ten square kilometers in the Ulastai Valley, Xin Jiang, China. The telescope will be built almost entirely of inexpensive commercially available off-the-shelf components. A series of tests of prototypes, made on-site, have allowed us to study the performance of the telescope and its components. We will present these results and show sky images obtained with the prototypes. We anticipate that one

  1. Lunar transit telescope lander design

    NASA Technical Reports Server (NTRS)

    Omar, Husam A.

    1991-01-01

    The Program Development group at NASA's Marshall Space Flight Center has been involved in studying the feasibility of placing a 16 meter telescope on the lunar surface to scan the skies using visible/ Ultraviolet/ Infrared light frequencies. The precursor telescope is now called the TRANSIT LUNAR TELESCOPE (LTT). The Program Development Group at Marshall Space Flight Center has been given the task of developing the basic concepts and providing a feasibility study on building such a telescope. The telescope should be simple with minimum weight and volume to fit into one of the available launch vehicles. The preliminary launch date is set for 2005. A study was done to determine the launch vehicle to be used to deliver the telescope to the lunar surface. The TITAN IV/Centaur system was chosen. The engineering challenge was to design the largest possible telescope to fit into the TITAN IV/Centaur launch system. The telescope will be comprised of the primary, secondary and tertiary mirrors and their supporting system in addition to the lander that will land the telescope on the lunar surface and will also serve as the telescope's base. The lunar lander should be designed integrally with the telescope in order to minimize its weight, thus allowing more weight for the telescope and its support components. The objective of this study were to design a lander that meets all the constraints of the launching system. The basic constraints of the TITAN IV/Centaur system are given.

  2. Lunar transit telescope lander design

    NASA Technical Reports Server (NTRS)

    Omar, Husam A.

    1992-01-01

    The Program Development group at NASA's Marshall Space Flight Center has been involved in studying the feasibility of placing a 16 meter telescope on the lunar surface to scan the skies using visible/ Ultraviolet/ Infrared light frequencies. The precursor telescope is now called the TRANSIT LUNAR TELESCOPE (LTT). The Program Development Group at Marshall Space Flight Center has been given the task of developing the basic concepts and providing a feasibility study on building such a telescope. The telescope should be simple with minimum weight and volume to fit into one of the available launch vehicles. The preliminary launch date is set for 2005. A study was done to determine the launch vehicle to be used to deliver the telescope to the lunar surface. The TITAN IV/Centaur system was chosen. The engineering challenge was to design the largest possible telescope to fit into the TITAN IV/Centaur launch system. The telescope will be comprised of the primary, secondary and tertiary mirrors and their supporting system in addition to the lander that will land the telescope on the lunar surface and will also serve as the telescope's base. The lunar lander should be designed integrally with the telescope in order to minimize its weight, thus allowing more weight for the telescope and its support components. The objective of this study were to design a lander that meets all the constraints of the launching system. The basic constraints of the TITAN IV/Centaur system are given.

  3. Science operations with Space Telescope

    NASA Technical Reports Server (NTRS)

    Giacconi, R.

    1982-01-01

    The operation, instrumentation, and expected contributions of the Space Telescope are discussed. Space Telescope capabilities are described. The organization and nature of the Space Telescope Science Institute are outlined, including the allocation of observing time and the data rights and data access policies of the institute.

  4. Lowell Observatory's Discovery Channel Telescope

    NASA Astrophysics Data System (ADS)

    Hall, Jeffrey C.

    2017-01-01

    Lowell Observatory broke ground on its 4.3-meter Discovery Channel Telescope (DCT) in July 2005 and celebrated first light for the telescope in July 2012. In this overview to this special session, I will discuss the origin and development of the project, the telescope's general specifications and performance, its current operating status, and the initial instrument suite.

  5. The Bionic Telescope

    NASA Astrophysics Data System (ADS)

    Woolf, Neville

    2009-05-01

    Four hundred years after children in a spectacle makers workshop accidentally discovered the telescope, the development of this device has been a continuous replacement of the ``natural'' by the deliberate. The human eye is gone. The lens is gone. The tube is gone. The dome is on the verge of going. The size of the optics are ceasing to be set by transportation limits. Adaptive optics are preferred to stable optics. We deliberately break the Lagrange invariant. We focus on lasers instead of stars, and natural observing environments are being replaced by adaptive environments. The goals for the new ground based telescope encompass the oldest and newest ideas, to find signs of life elsewhere, and to find how all the universe developed.

  6. Origins Space Telescope

    NASA Astrophysics Data System (ADS)

    Cooray, Asantha R.; Origins Space Telescope Study Team

    2017-01-01

    The Origins Space Telescope (OST) is the mission concept for the Far-Infrared Surveyor, a study in development by NASA in preparation for the 2020 Astronomy and Astrophysics Decadal Survey. Origins is planned to be a large aperture, actively-cooled telescope covering a wide span of the mid- to far-infrared spectrum. Its spectrographs will enable 3D surveys of the sky that will discover and characterize the most distant galaxies, Milky-Way, exoplanets, and the outer reaches of our Solar system. Origins will enable flagship-quality general observing programs led by the astronomical community in the 2030s. The Science and Technology Definition Team (STDT) would like to hear your science needs and ideas for this mission. The team can be contacted at firsurveyor_info@lists.ipac.caltech.edu. I will summarize the OST STDT, mission design and instruments, key science drivers, and the study plan over the next two years.

  7. Telescopic limiting magnitudes

    NASA Technical Reports Server (NTRS)

    Schaefer, Bradley E.

    1990-01-01

    The prediction of the magnitude of the faintest star visible through a telescope by a visual observer is a difficult problem in physiology. Many prediction formulas have been advanced over the years, but most do not even consider the magnification used. Here, the prediction algorithm problem is attacked with two complimentary approaches: (1) First, a theoretical algorithm was developed based on physiological data for the sensitivity of the eye. This algorithm also accounts for the transmission of the atmosphere and the telescope, the brightness of the sky, the color of the star, the age of the observer, the aperture, and the magnification. (2) Second, 314 observed values for the limiting magnitude were collected as a test of the formula. It is found that the formula does accurately predict the average observed limiting magnitudes under all conditions.

  8. Telescopes of galileo.

    PubMed

    Greco, V; Molesini, G; Quercioli, F

    1993-11-01

    The Florentine Istituto e Museo di Storia delta Scienza houses two complete telescopes and a single objective lens (reconstructed from several fragments) that can be attributed to Galileo. These optics have been partially dismantled and made available for optical testing with state-of-the-art equipment. The lenses were investigated individually; the focal length and the radii of curvature were measured, and the optical layout of the instruments was worked out. The optical quality of the surfaces and the overall performance of the two complete telescopes have been evaluated interferometrically at a wavelength of 633 nm (with a He-Ne laser source). It was found in particular that the optics of Galileo came close to attaining diffraction-limited operation.

  9. Galileo's wondrous telescope

    NASA Astrophysics Data System (ADS)

    Cartlidge, Edwin

    2008-06-01

    If you need reminding of just how wrong the great and the good can be, take a trip to the Museum of the History of Science in Florence, Italy. The museum is staging an exhibition entitled "Galileo's telescope - the instrument that changed the world" to mark the 400th anniversary this year of Galileo Galilei's revolutionary astronomical discoveries, which were made possible by the invention of the telescope. At the start of the 17th century, astronomers assumed that all the planets and the stars in the heavens had been identified and that there was nothing new for them to discover, as the exhibition's curator, Giorgio Strano, points out. "No-one could have imagined what wondrous new things were about to be revealed by an instrument created by inserting two eyeglass lenses into the ends of a tube," he adds.

  10. Telescopic horizon scanning.

    PubMed

    Koenderink, Jan

    2014-12-20

    The problem of "distortionless" viewing with terrestrial telescopic systems (mainly "binoculars") remains problematic. The so called "globe effect" is only partially counteracted in modern designs. Theories addressing the phenomenon have never reached definitive closure. In this paper, we show that exact distortionless viewing with terrestrial telescopic systems is not possible in general, but that it is in principle possible in-very frequent in battle field and marine applications-the case of horizon scanning. However, this involves cylindrical optical elements. For opto-electronic systems, a full solution is more readily feasible. The solution involves a novel interpretation of the relevant constraints and objectives. For final design decisions, it is not necessary to rely on a corpus of psychophysical (or ergonomic) data, although one has to decide whether the instrument is intended as an extension of the eye or as a "pictorial" device.

  11. Nonmechanical bifocal zoom telescope.

    PubMed

    Valley, Pouria; Reza Dodge, Mohammad; Schwiegerling, Jim; Peyman, Gholam; Peyghambarian, N

    2010-08-01

    We report on a novel zoom lens with no moving parts in the form of a switchable Galilean telescope. This zoom telescope consists of two flat liquid-crystal diffractive lenses with apertures of 10mm that can each take on the focal lengths of -50 and +100cm, with a spacing of 50cm and, hence, a zoom ratio of 4x. The lenses are driven using a low-voltage ac source with 1.6V and exhibit millisecond switching times. The spectral characteristic of this diffractive zoom system is evaluated for light sources of various bandwidths. Potential applications for this technology include a zoom lens with no moving parts for camera phones and medical imaging devices.

  12. TAUVEX - UV Space Telescope

    NASA Astrophysics Data System (ADS)

    Topaz, Jeremy; Braun, Ofer; Brosch, Noah

    1993-01-01

    The TAUVEX UV Space Telescope currently under construction by El-Op Ltd. in Israel is designed both for recording images of the sky in the UV region and to serve as the optical monitor for the SODART X-Ray Telescope being built by the Danish Space Research Institute. The two systems, together with several other experiments, will be flown on the S-R-G satellite to be launched by the CIS in 1995. TAUVEX will image a field of about 1 deg simultaneously in three spectral bands. In addition, it will record a selected object in a high-speed time-resolved mode in these bands. The concept and design of TAUVEX is described in this paper.

  13. The Neutrino Telescope ANTARES

    NASA Astrophysics Data System (ADS)

    Hernández, Juan José

    Neutrinos can reveal a brand new Universe at high energies. The ANTARES collaboration [1] , formed in 1996, works towards the building and deployment of a neutrino telescope. This detector could observe and study high energy astrophysical sources such as X-ray binary systems, young supernova remnants or Active Galactic Nuclei and help to discover or set exclusion limits on some of the elementary particles and objects that have been put forward as candidates to fill the Universe (WIMPS, neutralinos, topological deffects, Q-balls, etc). A neutrino telescope will certainly open a new observational window and can shed light on the most energetic phenomena of the Universe. A review of the progress made by the ANTARES collaboration to achieve this goal is presented

  14. ALMA telescope reaches new heights

    NASA Astrophysics Data System (ADS)

    2009-09-01

    The ALMA (Atacama Large Millimeter/submillimeter Array) astronomical observatory has taken another step forward - and upwards. One of its state-of-the-art antennas was carried for the first time to the 5000m plateau of Chajnantor, in the Chilean Andes, on the back of a custom-built giant transporter. The antenna, which weighs about 100 tons and has a diameter of 12 metres, was transported up to the high-altitude Array Operations Site, where the extremely dry and rarefied air is ideal for ALMA's observations of the Universe. The conditions at the Array Operations Site on Chajnantor, while excellent for astronomy, are also very harsh. Only half as much oxygen is available as at sea level, making it very difficult to work there. This is why ALMA's antennas are assembled and tested at the lower 2900 m altitude of the ALMA Operations Support Facility. It was from this relatively hospitable base camp that the ALMA antenna began its journey to the high Chajnantor site. "This is an important moment for ALMA. We are very happy that the first transport of an antenna to the high site went flawlessly. This achievement was only possible through contributions from all international ALMA partners: this particular antenna is provided by Japan, the heavy-lift transporter by Europe, and the receiving electronics inside the antenna by North America, Europe, and Asia", said Wolfgang Wild, European ALMA Project Manager. The trip began when one of the two ALMA transporters, named Otto, lifted the antenna onto its back. It then carried its heavy load along the 28 km road from the Operations Support Facility up to the Array Operations Site. While the transporter is capable of speeds of up to 12 km/hour when carrying an antenna, this first journey was made more slowly to ensure that everything worked as expected, taking about seven hours. The ALMA antennas are the most advanced submillimetre-wavelength antennas ever made. They are designed to operate fully exposed in the harsh conditions

  15. [Galileo and his telescope].

    PubMed

    Strebel, Christoph

    2006-01-01

    Galileo's publication of observations made with his newly reinvented telescope provoked a fierce debate. In April 1610 Martinus Horky, a young Bohemian astronomer, had an opportunity to make his own observations with Galileo's telescope in the presence of Antonio Magini and other astronomers. Horky and the other witnesses denied the adequacy of Galileo's telescope and therefore the bona fides of his discoveries. Kepler conjectured Horky as well as all his witnesses to be myopic. But Kepler's objection could not stop the publication of Horky's Peregrinatio contra nuncium sidereum (Modena, 1610), the first printed refutation of Galileo's Sidereus nuncius. In his treatise, Horky adresses four questions: 1) Do the four newly observed heavenly bodies actually exist? Horky denies their existence on various grounds: a) God, as every astronomer teaches, has created only seven moveable heavenly bodies and astronomical knowledge originates in God, too. b) Heavenly bodies are either stars or planets. Galileo's moveable heavenly bodies fit into neither category. c) If they do exist, why have they not already been observed by other scholars? Horky concludes that there are no such heavenly bodies. 2) What are these phenomena? They are purely artefactual, and produced by Galileo's telescope. 3) How are they like? Galileo's "stars" are so small as to be almost invisible. Galileo claims that he has measured their distances from each other. This however is impossible due to their diminutive size and other observational problems. Hence, Galileo's claim is a further proof that he is a fraud. 4) Why are they? For Galileo they are a chance to earn money but for astronomers like Horky they are a reason to offer thanks and honour to God. Horky's treatise was favourably received by the enemies of Galileo. But Kepler's critique was devastating. After calling on Kepler in Prague, Horky had to revoke the contents of his book.

  16. The Large Area Telescope

    SciTech Connect

    Michelson, Peter F.; /KIPAC, Menlo Park /Stanford U., HEPL

    2007-11-13

    The Large Area Telescope (LAT), one of two instruments on the Gamma-ray Large Area Space Telescope (GLAST) mission, is an imaging, wide field-of-view, high-energy pair-conversion telescope, covering the energy range from {approx}20 MeV to more than 300 GeV. The LAT is being built by an international collaboration with contributions from space agencies, high-energy particle physics institutes, and universities in France, Italy, Japan, Sweden, and the United States. The scientific objectives the LAT will address include resolving the high-energy gamma-ray sky and determining the nature of the unidentified gamma-ray sources and the origin of the apparently isotropic diffuse emission observed by EGRET; understanding the mechanisms of particle acceleration in celestial sources, including active galactic nuclei, pulsars, and supernovae remnants; studying the high-energy behavior of gamma-ray bursts and transients; using high-energy gamma-rays to probe the early universe to z {ge} 6; and probing the nature of dark matter. The components of the LAT include a precision silicon-strip detector tracker and a CsI(Tl) calorimeter, a segmented anticoincidence shield that covers the tracker array, and a programmable trigger and data acquisition system. The calorimeter's depth and segmentation enable the high-energy reach of the LAT and contribute significantly to background rejection. The aspect ratio of the tracker (height/width) is 0.4, allowing a large field-of-view and ensuring that nearly all pair-conversion showers initiated in the tracker will pass into the calorimeter for energy measurement. This paper includes a description of each of these LAT subsystems as well as a summary of the overall performance of the telescope.

  17. Casa-Blanca: A Large non-imaging Cerenkov Detector at Casa-Mia

    NASA Astrophysics Data System (ADS)

    Cassidy, M.; Fortson, L. F.; Fowler, J. W.; Jui, C. H.; Kieda, D. B.; Loh, E. C.; Ong, R. A.; Sommers, P.

    The lateral distribution of Cherenkov light at ground level records important information on the development of the cosmic ray air shower which produces it. We have constructed an array of 144 non-imaging Cherenkov detectors at the CASA-MIA experiment site in Dugway, Utah. The various arrays can sample simultaneously the lateral distributions of electrons, muons, and Cherenkov light at many locations. We describe the design and operation of the CASA-BLANCA experiment and its potential to address the composition of primary cosmic rays between 300 and 30,000 TeV.

  18. Hubble Space Telescope satellite

    NASA Technical Reports Server (NTRS)

    Mitchell, R. E.

    1985-01-01

    The Hubble Space Telescope, named for the American astronomer Edwin Powell Hubble, will be the largest and most powerful astronomical instrument ever orbited. Placed above the obscuring effects of the earth's atmosphere in a 600-km orbit, this remotely-controlled, free-flying satellite observatory will expand the terrestrial-equivalent resolution of the universe by a factor of seven, or a volumetric factor of 350. This telescope has a 2.4-m primary mirror and can accommodate five scientific instruments (cameras, spectrographs and photometers). The optics are suitable for a spectral range from 1100 angstrom to 1 mm wavelength. With a projected service life of fifteen years, the spacecraft can be serviced on-orbit for replacement of degraded systems, to insert advanced scientific instruments, and to reboost the telescope from decayed altitudes. The anticipated image quality will be a result of extremely precise lambda/20 optics, stringent cleanliness, and very stable pointing: jitter will be held to less than 0.01 arcsecond for indefinite observation periods, consistent with instrument apertures as small as 0.1 arcsecond.

  19. Cerenkov Maser and Cerenkov Laser Devices.

    DTIC Science & Technology

    1982-12-01

    Nauk. SSSR 3,253. 11. Coleman, P., and Enderby, C. (1960). J. Appl. Phys. 31, 1695. 12. Danos , M. ( 1953 ). J. Appl. Phys. 26,2. 13. Lashinsky, H. (1956...by Danos , by Lashinsky, 1 3 and by Ulrich. 14 In these experiments, no provision was made for feeding back the emitted radia- tion on subsequent...Ginzburg, Dok. Akad. Nauk SSSR 56,253 (1947). 4M. Abele, Nouvo Cimento 9, 207 (1952). In conclusion, the above experiments have demonstrat- ’M. Danos , S

  20. Camera Development for the Cherenkov Telescope Array

    NASA Astrophysics Data System (ADS)

    Moncada, Roberto Jose

    2017-01-01

    With the Cherenkov Telescope Array (CTA), the very-high-energy gamma-ray universe, between 30 GeV and 300 TeV, will be probed at an unprecedented resolution, allowing deeper studies of known gamma-ray emitters and the possible discovery of new ones. This exciting project could also confirm the particle nature of dark matter by looking for the gamma rays produced by self-annihilating weakly interacting massive particles (WIMPs). The telescopes will use the imaging atmospheric Cherenkov technique (IACT) to record Cherenkov photons that are produced by the gamma-ray induced extensive air shower. One telescope design features dual-mirror Schwarzschild-Couder (SC) optics that allows the light to be finely focused on the high-resolution silicon photomultipliers of the camera modules starting from a 9.5-meter primary mirror. Each camera module will consist of a focal plane module and front-end electronics, and will have four TeV Array Readout with GSa/s Sampling and Event Trigger (TARGET) chips, giving them 64 parallel input channels. The TARGET chip has a self-trigger functionality for readout that can be used in higher logic across camera modules as well as across individual telescopes, which will each have 177 camera modules. There will be two sites, one in the northern and the other in the southern hemisphere, for full sky coverage, each spanning at least one square kilometer. A prototype SC telescope is currently under construction at the Fred Lawrence Whipple Observatory in Arizona. This work was supported by the National Science Foundation's REU program through NSF award AST-1560016.

  1. The Aloha Telescope for K-12 STEM Education

    NASA Astrophysics Data System (ADS)

    Sowell, James R.

    2015-01-01

    How does one bring night-time astronomical observations into the classroom? How does a teacher - during the school day - show students the craters on the Moon, the rings of Saturn, or the four Galilean moons of Jupiter? One of the greatest drawbacks to teaching Astronomy is the lack of real-time telescopic observations during the school day, and yet this is a very exciting time for astronomical discoveries. The solution is to access a telescope in a substantially different time zone where it is still night. This facility - the Aloha Telescope - on Maui has already been established by a partnership between Georgia Tech and the Air Force Research Lab. This robotic telescope's sole purpose is for K-12 education, as it is equipped with a video-camera and is operated remotely via high-speed internet connections. This facility and its outreach program allow east-coast teachers and, in turn, students to have local daytime access to - and direct control of - the telescope. When observing the Moon, teachers and students will move the telescope wherever they wish across the highly-magnified lunar surface (~ 5 arcminute FOV). This telescope will enable night-time astronomical observations to come alive as day-time activities and will be an important tool for STEM education and activities. The use of the Aloha Telescope requires minimal training and is free after registering for a date and time.Dr. Sowell has written specific telescopic exercises and surface feature tours appropriate for K-12 and college-level users. These exercises, and other aspects of the Aloha Telescope and program, are posted on the website at http://aloha.gatech.edu

  2. Velocity distributions produced by a thermionic electron gun and the effect on the performance of a Cerenkov FEL

    SciTech Connect

    Van der Slot, P.J.M.; Voronin, V.S.

    1995-12-31

    For a normal thermionic electron gun, with a limited emission current density of the order of 10 A/cM{sup 2}, (magnetic) beam compression is required to obtain an electron beam with a current of up to 100 A with a small diameter. This method is used in an electron gun for a Cerenkov FEL (CFEL). When the electron beam is compressed from its initial dimensions at the cathode to its final dimensions in the interaction region of the CFEL, the electrons obtain a small transverse momentum and perform a Larmor motion around a centre given by the magnetic field fines. The amount of transverse momentum obtained depends on the field at the cathode B{sub c} and the field B{sub o} at the final compressed beam. By using a so called bump coil it becomes possible to tune the magnetic field to obtain zero transverse momentum for electrons emitted at a certain radius r{sub z} at the cathode. However it is not possible to have zero transverse momentum over the complete cathode surface since it is not possible to vary the magnetic field over the beam dimensions. Computation of single particle trajectories in the given electrostatic accelerating and magnetostatic compression fields show that the transverse momentum in the interaction region is nearly linear with the displacement from r{sub z} where the proportionality constant k{sub p} is a constant which depends on B{sub c} and B{sub o} but is almost independent of r{sub z} when the bump coil position and field strength are optimised for each value of r{sub z}. One thus finds that the longitudinal velocity distribution as a function of radial position is parabolic of shape and that the position of the maximum is determined by the position of r{sub z}. Using these type of velocity distributions nonlinear simulations of the CFEL have been performed.

  3. SU-E-T-111: Development of Proton Dosimetry System Using Fiber-Optic Cerenkov Radiation Sensor Array

    SciTech Connect

    Son, J; Kim, M; Shin, D; Lim, Y; Lee, S; Kim, J; Kim, J; Hwang, U; Yoon, M

    2014-06-01

    Purpose: We had developed and evaluated a new dosimetric system for proton therapy using array of fiber-optic Cerenkov radiation sensor (FOCRS) which can measure a percent depth dose (PDD) instantly. In this study, the Bragg peaks and spread out Bragg peak (SOBP) of the proton beams measured by FOCRS array were compared with those measured by an ion chamber. Methods and Method: We fabricated an optical fiber array of FOCRS in a handmade phantom which is composed of poly-methyl methacrylate (PMMA). There are 75 holes of 1mm diameter inside the phantom which is designed to be exposed in direction of beam when it is emerged in water phantom. The proton beam irradiation was carried out using IBA cyclotron PROTEUS 235 at national cancer center in Korea and a commercial data acquisition system was used to digitize the analog signal. Results: The measured Bragg peak and SOBP for the proton ranges of 7∼ 20 cm were well matched with the result from ion chamber. The comparison results show that the depth of proton beam ranges and the width of SOBP measured by array of FOCRS are comparable with the measurement from multi-layer ion chamber (MLIC) although there are some uncertainty in the measurement of FOCRS array for some specific beam ranges. Conclusion: The newly developed FOCRS array based dosimetric system for proton therapy can efficiently reduce the time and effort needed for proton beam range measurement compared to the conventional method and has the potential to be used for the proton pencil beam application.

  4. Portable instrument for inspecting irradiated nuclear-fuel assemblies in a water-filled storage pond by measurement of induced Cerenkov radiation

    DOEpatents

    Nicholson, N.; Dowdy, E.J.; Holt, D.M.; Stump, C.J. Jr.

    1982-05-13

    A portable instrument for measuring induced Cerenkov radiation associated with irradiated nuclear fuel assemblies in a water-filled storage pond is disclosed. The instrument includes a photomultiplier tube and an image intensifier which are operable in parallel and simultaneously by means of a field lens assembly and an associated beam splitter. The image intensifier permits an operator to aim and focus the apparatus on a submerged fuel assembly. Once the instrument is aimed and focused, an illumination reading can be obtained with the photomultiplier tube. The instrument includes a lens cap with a carbon-14/phosphor light source for calibrating the apparatus in the field.

  5. Comparing NEO Search Telescopes

    NASA Astrophysics Data System (ADS)

    Myhrvold, Nathan

    2016-04-01

    Multiple terrestrial and space-based telescopes have been proposed for detecting and tracking near-Earth objects (NEOs). Detailed simulations of the search performance of these systems have used complex computer codes that are not widely available, which hinders accurate cross-comparison of the proposals and obscures whether they have consistent assumptions. Moreover, some proposed instruments would survey infrared (IR) bands, whereas others would operate in the visible band, and differences among asteroid thermal and visible-light models used in the simulations further complicate like-to-like comparisons. I use simple physical principles to estimate basic performance metrics for the ground-based Large Synoptic Survey Telescope and three space-based instruments—Sentinel, NEOCam, and a Cubesat constellation. The performance is measured against two different NEO distributions, the Bottke et al. distribution of general NEOs, and the Veres et al. distribution of Earth-impacting NEO. The results of the comparison show simplified relative performance metrics, including the expected number of NEOs visible in the search volumes and the initial detection rates expected for each system. Although these simplified comparisons do not capture all of the details, they give considerable insight into the physical factors limiting performance. Multiple asteroid thermal models are considered, including FRM, NEATM, and a new generalized form of FRM. I describe issues with how IR albedo and emissivity have been estimated in previous studies, which may render them inaccurate. A thermal model for tumbling asteroids is also developed and suggests that tumbling asteroids may be surprisingly difficult for IR telescopes to observe.

  6. The Planck Telescope reflectors

    NASA Astrophysics Data System (ADS)

    Stute, Thomas

    2004-09-01

    The mechanical division of EADS-Astrium GmbH, Friedrichshafen is currently engaged with the development, manufacturing and testing of the advanced dimensionally stable composite reflectors for the ESA satellite borne telescope Planck. The objective of the ESA mission Planck is to analyse the first light that filled the universe, the cosmic microwave background radiation. Under contract of the Danish Space Research Institute and ESA EADS-Astrium GmbH is developing the all CFRP primary and secondary reflectors for the 1.5-metre telescope which is the main instrument of the Planck satellite. The operational frequency ranges from to 25 GHz to 1000 GHz. The demanding high contour accuracy and surface roughness requirements are met. The design provides the extreme dimensional stability required by the cryogenic operational environment at around 40 K. The elliptical off-axis reflectors display a classical lightweight sandwich design with CFRP core and facesheets. Isostatic mounts provide the interfaces to the telescope structure. Protected VDA provides the reflecting surface. The manufacturing is performed at the Friedrichshafen premises of EADS-Space Transportation GmbH, the former Dornier composite workshops. Advanced manufacturing technologies like true angle lay-up by CNC fibre placement and filament winding are utilized. The protected coating is applied at the CAHA facilities at the Calar Alto Observatory, Spain. The exhaustive environmental testing is performed at the facilities of IABG, Munich (mechanical testing) and for the cryo-optical tests at CSL Liege. The project is in advanced state with both Qualification Models being under environmental testing. The flight models will be delivered in 2004. The paper gives an overview over the requirements and the main structural features how these requirements are met. Special production aspects and available test results are reported.

  7. Is Your Telescope Tweeting?

    NASA Astrophysics Data System (ADS)

    Atkinson, Nancy

    2009-05-01

    Half of the world's population today was born after the Apollo Moon landings. The best way to reach this generation and get them excited about today's space exploration and astronomy news and events is through online social media, which are technologies that allow anyone to communicate with everyone. Twitter is a growing popular social media tool that uses short, 140 character "Tweets" to quickly and concisely convey updates on what you "are doing." With the right combination of information, personality and fun, telescopes and spacecraft are using Twitter for public outreach, providing important status updates while making the public feel like they are part of the mission.

  8. Fiber-linked telescope array: description and laboratory tests of a two-channel prototype.

    PubMed

    Alleman, J J; Reynaud, F; Connes, P

    1995-05-01

    We present a complete two-telescope version of a fiber-linked coherent array that is meant to be used for mounting on the dish of a radio telescope. This was built with 20-cm amateur telescopes and includes three different servo subsystems for guiding, nulling of the air path difference, and fiber length control. Laboratory tests of the fully integrated system in front of a star simulator are described.

  9. SST dual-mirror telescopes for the Cherenkov Telescope Array

    NASA Astrophysics Data System (ADS)

    Dumas, Delphine; Laporte, Philippe; Sol, Hélène; Pareschi, Giovanni; Canestrari, Rodolfo; Stringhetti, Luca; Catalano, Osvaldo; White, Richard; Greenshaw, Tim; Hinton, Jim; Blake, Simon

    2014-07-01

    The Cherenkov Telescope Array (CTA) is an international collaboration that aims to create the world's foremost very high energy gamma-ray observatory, composed of large, medium and small size telescopes (SST). The SSTs will be the most numerous telescopes on site and will focus on capturing the rarer highest energy photons. Three prototypes of SST are designed and currently under construction; two of them, ASTRI and SST-GATE, have been designed, based on a dual-mirror Schwarzschild-Couder (SC) design which has never been built before for any astronomical observation. The SC optical design allows for a small plate scale, a wide field of view and a lightweight cameras aiming to minimize the cost of SST telescopes in order to increase their number in the array. The aim of this article is to report the progress of the two telescope projects prototyping telescope structures and cameras for the Small Size Telescopes for CTA. After a discussion of the CTA project and its scientific objectives, the performance of the SC design is described, with focus on the specific designs of SST-GATE and ASTRI telescopes. The design of both prototypes and their progress is reported in the current prototyping phase. The designs of Cherenkov cameras, CHEC and ASTRI, to be mounted on these telescopes are discussed and progresses are reported.

  10. SNAP Telescope Latest Developments

    NASA Astrophysics Data System (ADS)

    Lampton, M.; SNAP Collaboration

    2004-12-01

    The coming era of precision cosmology imposes new demands on space telescopes with regard to spectrophotometric accuracy and image stability. To meet these requirements for SNAP we have developed an all reflecting two-meter-class space telescope of the three-mirror anastigmat type. Our design features a large flat annular field (1.5 degrees = 580mm diameter) and a telephoto advantage of 6, delivering a 22m focal length within an optical package length of only 3.5 meters. The use of highly stable materials (Corning ULE glass and carbon-fiber reinforced cyanate ester resin for the metering structure) combined with agressive distributed thermal control and an L2 orbit location will lead to unmatched figure stability. Owing to our choice of rigid structure with nondeployable solar panels, finite-element models show no structural resonances below 10Hz. An exhaustive stray light study has been completed. Beginning in 2005, two industry studies will develop plans for fabrication, integration and test, bringing SNAP to a highly realistic level of definition. SNAP is supported by the Office of Science, US DoE, under contract DE-AC03-76SF00098.

  11. The CCAT Telescope

    NASA Astrophysics Data System (ADS)

    Glenn, Jason; CCAT

    2013-01-01

    CCAT will be a 25 m diameter on-axis Gregory telescope operating in the 0.2 to 2.1 mm wavelength range. It will be located at an altitude of 5600 m on Cerro Chajnantor in northern Chile. CCAT will support cameras and spectrometers with up to 1 field of view at its f/6 Nasmyth foci. The key performance requirements for the telescope are a half wavefront error <12.5 μm rms and pointing error <0.35"/350 μm). CCAT will have an f/0.4 primary with an active surface to compensate gravitational and thermal deformations. The primary will be made of 2 m keystone-shaped segments, each with 16 machined aluminum tiles mounted on a carbon-fiber-reinforced-plastic (CFRP) subframe. The segments will be supported by a CFRP spaceframe truss on an elevation over azimuth mount made of steel. CCAT will be inside an enclosure to reduce wavefront and pointing errors due to wind forces and thermal deformation due to solar illumination.

  12. The Green Bank Telescope

    NASA Astrophysics Data System (ADS)

    Jewell, P. R.

    1999-12-01

    The Green Bank Telescope The 100-m NRAO Green Bank Telescope will be completed in early 2000. The GBT has a large number of unique design and performance features that will give it unprecedented scientific capability. This poster display will review those features, which include an offset feed (clear aperture) design, an active surface, a closed-loop laser metrology system for surface figure and pointing control, broad frequency coverage from 100 MHz to 115 GHz, a versatile receiver selection mechanism, and a new multi-input, 256k-channel autocorrelation spectrometer. The status of the project, the commissioning schedule, plans for early operations, the initial instrumentation suite, and plans for future instrumentation will be reviewed. Scientific areas for which the GBT will have a large impact will be discussed, including observations of young galaxies at extreme redshifts, pulsars, HI and molecular spectroscopy, VLBI work, and millimeter-wave spectroscopy and continuum studies. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

  13. Magellan Telescopes operations 2008

    NASA Astrophysics Data System (ADS)

    Osip, David J.; Phillips, Mark M.; Palunas, Povilas; Perez, Frank; Leroy, M.

    2008-07-01

    The twin 6.5m Magellan Telescopes have been in routine operations at the Las Campanas Observatory in the Chilean Andes since 2001 and 2002 respectively. The telescopes are owned and operated by Carnegie for the benefit of the Magellan consortium members (Carnegie Institution of Washington, Harvard University, the University of Arizona, Massachusetts Institute of Technology, and the University of Michigan). This paper provides an up to date review of the scientific, technical, and administrative structure of the 'Magellan Model' for observatory operations. With a modest operations budget and a reasonably small staff, the observatory is operated in the "classical" mode, wherein the visiting observer is a key member of the operations team. Under this model, all instrumentation is supplied entirely by the consortium members and the various instrument teams continue to play a critical support role beyond initial deployment and commissioning activities. Here, we present a critical analysis of the Magellan operations model and suggest lessons learned and changes implemented as we continue to evolve an organizational structure that can efficiently deliver a high scientific return for the investment of the partners.

  14. Near anastigmatic grazing incidence telescope

    NASA Technical Reports Server (NTRS)

    Korsch, D.

    1984-01-01

    A performance capability assessment is presently conducted for short versus long grazing incidence telescope designs, in view of the observation that the field curvature and astigmatism that are the primary residual aberrations of a Wolter-type incidence telescope can be substantially reduced through mirror length reduction. A major advantage of the short element telescope is that, if sufficiently short, both the paraboloid and hyperboloid surfaces may be fabricated as a single piece; this significantly facilitates the task of alignment.

  15. Cost Modeling for Space Telescope

    NASA Technical Reports Server (NTRS)

    Stahl, H. Philip

    2011-01-01

    Parametric cost models are an important tool for planning missions, compare concepts and justify technology investments. This paper presents on-going efforts to develop single variable and multi-variable cost models for space telescope optical telescope assembly (OTA). These models are based on data collected from historical space telescope missions. Standard statistical methods are used to derive CERs for OTA cost versus aperture diameter and mass. The results are compared with previously published models.

  16. TANGO ARRAY I: An Air Shower Experiment in Buenos Aires

    NASA Astrophysics Data System (ADS)

    Bauleo, P.; Bonifazi, C.; Filevich, A.; Reguera, A.

    The TANGO Array is an air shower experiment which has been recently constructed in Buenos Aires, Argentina. It became fully operational in September, 2000. The array consists of 4 water ˇCerenkov detector stations enclosing a geometrical area of ˜ 30.000 m2 and its design has been optimized for the observation of EAS produced by cosmic rays near the "knee" energy region. Three of the detectors have been constructed using 12000-liter stainless steel tanks, and the fourth has been mounted in a smaller, 400liter plastic container. The detectors are connected by cables to the data acquisition room, where a fully automatic system, which takes advantage of the features of a 4-channel digital oscilloscope, was set for data collection without the need of operator intervention. This automatic experiment control includes monitoring, data logging, and daily calibration of all stations. This paper describes the detectors and their associated electronics, and details are given on the data acquisition system, the triggering and calibration procedures, and the operation of the array. Examples of air shower traces, recorded by the array, are presented.

  17. Performance modeling of launch vehicle imaging telescopes

    NASA Astrophysics Data System (ADS)

    Harvey, James E.; Krywonos, Andrey; Houston, Joseph B., Jr.

    2005-09-01

    The implementation plan for the "return-to-flight" of the space shuttle after the spectacular Columbia disaster upon re-entering the earth's atmosphere on February 1, 2003 included significant upgrades to the Ground Camera Ascent Imagery assets at Kennedy Space Center (KSC) and Cape Canaveral Air Force Station. The accident was due to damage incurred when a piece if insulating foam debris from the external fuel tank struck the left wing during take-off. The Ground Camera Ascent Imagery Project encompasses a wide variety of launch vehicle tracking telescopes and cameras at the Eastern Range. Most of these launch vehicle imaging telescopes are manually tracked and fitted with video and 35 mm film cameras, and many of them are fixed-focus (i.e., focused at the hyperfocal distance for the duration of the launch). In this paper we describe a systems engineering analysis approach for obtaining performance predictions of these aging launch vehicle imaging telescopes. Recommendations for a continuing maintenance and refurbishment program that closes the loop around the KSC photo-interpreter are included.

  18. Large space telescope, phase A. Volume 3: Optical telescope assembly

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The development and characteristics of the optical telescope assembly for the Large Space Telescope are discussed. The systems considerations are based on mission-related parameters and optical equipment requirements. Information is included on: (1) structural design and analysis, (2) thermal design, (3) stabilization and control, (4) alignment, focus, and figure control, (5) electronic subsystem, and (6) scientific instrument design.

  19. Gamma-Ray Telescopes: 400 Years of Astronomical Telescopes

    NASA Technical Reports Server (NTRS)

    Gehrels, Neil; Cannizzo, John K.

    2010-01-01

    The last half-century has seen dramatic developments in gamma-ray telescopes, from their initial conception and development through to their blossoming into full maturity as a potent research tool in astronomy. Gamma-ray telescopes are leading research in diverse areas such as gamma-ray bursts, blazars, Galactic transients, and the Galactic distribution of Al-26.

  20. The Travelling Telescope

    NASA Astrophysics Data System (ADS)

    Owen, Daniel

    2015-08-01

    The telescope has been around for over 400 years, yet most people have never looked though one. We invite people outside under the stars to learn about those curious lights in the sky, and have a close encounter with the cosmos.Our main aim is to promote science, technology, engineering, and mathematics to the young minds by inspiring, empowering and engaging them using astronomy and astrophysics tools and concepts. We would like to see Africa compete with the rest of the world and we believe this can happen through having a scientifically literate society. We also work closely wit teachers, parents and the general public to further our objectives. We will present on our recently awarded project to work with schools in rural coastal Kenya, a very poor area of the country. We will also present on other work we continue to do with schools to make our project sustainable even after the OAD funding.

  1. Hubble Space Telescope Image

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Astronomers using the Hubble Space Telescope (HST) have identified what may be the most luminous star known; a celestial mammoth that releases up to 10-million times the power of the Sun and is big enough to fill the diameter of Earth's orbit. The star unleashes as much energy in six seconds as our Sun does in one year. The image, taken by a UCLA-led team with the recently installed Near-Infrared Camera and Multi-Object Spectrometer (NICMOS) aboard the HST, also reveals a bright nebula, created by extremely massive stellar eruptions. The UCLA astronomers estimate that the star, called the Pistol Star, (for the pistol shaped nebula surrounding it), is approximately 25,000 light-years from Earth, near the center of our Milky Way galaxy. The Pistol Star is not visible to the eye, but is located in the direction of the constellation Sagittarius, hidden behind the great dust clouds along the Milky Way

  2. Composite telescope technology

    NASA Astrophysics Data System (ADS)

    Chen, Peter C.; Rabin, Douglas

    2014-07-01

    We report the development of optical mirrors based on polymer matrix composite materials. Advantages of this technology are low cost and versatility. By using appropriate combinations of polymers and various metallic and nonmetallic particles and fibers, the properties of the materials can be tailored to suit a wide variety of applications. We report the fabrication and testing of flat and curved mirrors made with metal powders, multiple mirrors replicated with high degree of uniformity from the same mandrels, cryogenic testing, mirrors made of ferromagnetic materials that can be actively or adaptively controlled by non-contact actuation, optics with very smooth surfaces made by replication, and by spincasting. We discuss development of a new generation of ultra-compact, low power active optics and 3D printing of athermal telescopes.

  3. Actuated Hybrid Mirror Telescope

    NASA Technical Reports Server (NTRS)

    Hickey, Gregory; Redding, David; Lowman, Andrew; Cohen, David; Ohara, Catherine

    2005-01-01

    The figure depicts the planned Actuated Hybrid Mirror Telescope (AHMT), which is intended to demonstrate a new approach to the design and construction of wide-aperture spaceborne telescopes for astronomy and Earth science. This technology is also appropriate for Earth-based telescopes. The new approach can be broadly summarized as using advanced lightweight mirrors that can be manufactured rapidly at relatively low cost. More specifically, it is planned to use precise replicated metallic nanolaminate mirrors to obtain the required high-quality optical finishes. Lightweight, dimensionally stable silicon carbide (SiC) structures will support the nanolaminate mirrors in the required surface figures. To enable diffraction- limited telescope performance, errors in surface figures will be corrected by use of mirror-shape-control actuators that will be energized, as needed, by a wave-front-sensing and control system. The concepts of nanolaminate materials and mirrors made from nanolaminate materials were discussed in several previous NASA Tech Briefs articles. Nanolaminates constitute a relatively new class of materials that can approach theoretical limits of stiffness and strength. Nanolaminate mirrors are synthesized by magnetron sputter deposition of metallic alloys and/or compounds on optically precise master surfaces to obtain optical-quality reflector surfaces backed by thin shell structures. As an integral part of the deposition process, a layer of gold that will constitute the reflective surface layer is deposited first, eliminating the need for a subsequent and separate reflective-coating process. The crystallographic textures of the nanolaminate will be controlled to optimize the performance of the mirror. The entire deposition process for making a nanolaminate mirror takes less than 100 hours, regardless of the mirror diameter. Each nanolaminate mirror will be bonded to its lightweight SiC supporting structure. The lightweight nanolaminate mirrors and Si

  4. The Metagenomic Telescope

    PubMed Central

    Szalkai, Balázs; Scheer, Ildikó; Nagy, Kinga; Vértessy, Beáta G.; Grolmusz, Vince

    2014-01-01

    Next generation sequencing technologies led to the discovery of numerous new microbe species in diverse environmental samples. Some of the new species contain genes never encountered before. Some of these genes encode proteins with novel functions, and some of these genes encode proteins that perform some well-known function in a novel way. A tool, named the Metagenomic Telescope, is described here that applies artificial intelligence methods, and seems to be capable of identifying new protein functions even in the well-studied model organisms. As a proof-of-principle demonstration of the Metagenomic Telescope, we considered DNA repair enzymes in the present work. First we identified proteins in DNA repair in well–known organisms (i.e., proteins in base excision repair, nucleotide excision repair, mismatch repair and DNA break repair); next we applied multiple alignments and then built hidden Markov profiles for each protein separately, across well–researched organisms; next, using public depositories of metagenomes, originating from extreme environments, we identified DNA repair genes in the samples. While the phylogenetic classification of the metagenomic samples are not typically available, we hypothesized that some very special DNA repair strategies need to be applied in bacteria and Archaea living in those extreme circumstances. It is a difficult task to evaluate the results obtained from mostly unknown species; therefore we applied again the hidden Markov profiling: for the identified DNA repair genes in the extreme metagenomes, we prepared new hidden Markov profiles (for each genes separately, subsequent to a cluster analysis); and we searched for similarities to those profiles in model organisms. We have found well known DNA repair proteins, numerous proteins with unknown functions, and also proteins with known, but different functions in the model organisms. PMID:25054802

  5. The metagenomic telescope.

    PubMed

    Szalkai, Balázs; Scheer, Ildikó; Nagy, Kinga; Vértessy, Beáta G; Grolmusz, Vince

    2014-01-01

    Next generation sequencing technologies led to the discovery of numerous new microbe species in diverse environmental samples. Some of the new species contain genes never encountered before. Some of these genes encode proteins with novel functions, and some of these genes encode proteins that perform some well-known function in a novel way. A tool, named the Metagenomic Telescope, is described here that applies artificial intelligence methods, and seems to be capable of identifying new protein functions even in the well-studied model organisms. As a proof-of-principle demonstration of the Metagenomic Telescope, we considered DNA repair enzymes in the present work. First we identified proteins in DNA repair in well-known organisms (i.e., proteins in base excision repair, nucleotide excision repair, mismatch repair and DNA break repair); next we applied multiple alignments and then built hidden Markov profiles for each protein separately, across well-researched organisms; next, using public depositories of metagenomes, originating from extreme environments, we identified DNA repair genes in the samples. While the phylogenetic classification of the metagenomic samples are not typically available, we hypothesized that some very special DNA repair strategies need to be applied in bacteria and Archaea living in those extreme circumstances. It is a difficult task to evaluate the results obtained from mostly unknown species; therefore we applied again the hidden Markov profiling: for the identified DNA repair genes in the extreme metagenomes, we prepared new hidden Markov profiles (for each genes separately, subsequent to a cluster analysis); and we searched for similarities to those profiles in model organisms. We have found well known DNA repair proteins, numerous proteins with unknown functions, and also proteins with known, but different functions in the model organisms.

  6. Kashima 34-m Radio Telescope

    NASA Technical Reports Server (NTRS)

    Sekido, Mamoru; Kawai, Eiji

    2013-01-01

    The Kashima 34-m radio telescope has been continuously operated and maintained by the National Institute of Information and Communications Technology (NICT) as a facility of the Kashima Space Technology Center (KSTC) in Japan. This brief report summarizes the status of this telescope, the staff, and activities during 2012.

  7. Astrometry with Hubble Space Telescope

    NASA Astrophysics Data System (ADS)

    Benedict, G.; Murdin, P.

    2000-11-01

    In 1990 NASA launched the HUBBLE SPACE TELESCOPE. In addition to cameras and spectrographs usable from the far ultraviolet to the near-infrared, the observatory contains three white-light INTERFEROMETERS. As part of engineering and science support their primary task was telescope guiding; to position and hold science targets within the science instrument apertures with tolerances approaching 0.1'...

  8. Telescopes, Mounts and Control Systems

    NASA Astrophysics Data System (ADS)

    Mobberley, M.; Murdin, P.

    2003-04-01

    The amateur astronomer used to have a relatively basic choice of equipment: a refractor (see REFRACTING TELESCOPES), or a Newtonian reflector (see REFLECTING TELESCOPES); there were few other options. The refractor has always been the stereotype astronomer's instrument: a spy glass, with a lens at one end and an eyepiece at the other. However, in practice, the reflector has always been better aper...

  9. Daytime Use of Astronomical Telescopes for Deep-Space Optical Links

    NASA Technical Reports Server (NTRS)

    Roberts, W. Thomas; Ortiz, Gerard G.; Boyd, Tim A.

    2006-01-01

    Tests at the 200-inch Hale Telescope on Palomar Mountain have demonstrated this telescope's ability to withstand considerable thermal stress, and subsequently produce remarkably unaffected results. During the day of June 29,2005, the Hale telescope dome was left open, and the telescope was exposed to outside air and direct sunlight for 8 hours. During this time, portions of the telescope structure in the telescope's optical path experienced temperature elevations of 30 C, while the primary mirror experienced unprecedented heating of over 3 C. The telescope's measured blind pointing accuracy after this exposure was not noticeably degraded from the measurements taken before exposure. More remarkably, the telescope consistently produced stellar images which were significantly better after exposure of the telescope (1.2 arcsec) than before (1.6 arcsec), even though the conditions of observation were similar. This data is the first step in co-opting astronomical telescopes for daytime use as astronomical receivers, and supports the contention that deleterious effects from daytime exposure of the telescope can be held to an acceptable level for interleaved communications and astronomy.

  10. ALMA Telescope Reaches New Heights

    NASA Astrophysics Data System (ADS)

    2009-09-01

    The ALMA (Atacama Large Millimeter/submillimeter Array) astronomical observatory took another step forward and upward, as one of its state-of-the-art antennas was carried for the first time to Chile's 16,500-foot-high plateau of Chajnantor on the back of a giant, custom-built transporter. The 40-foot-diameter antenna, weighing about 100 tons, was moved to ALMA's high-altitude Array Operations Site, where the extremely dry and rarefied air is ideal for observing the Universe. The conditions at the Array Operations Site on Chajnantor, while excellent for astronomy, are also very harsh. Only about half as much oxygen is available as at sea level, making it very difficult to work there. This is why ALMA's antennas are assembled and tested at the lower 9,500-foot altitude of the ALMA Operations Support Facility (OSF). It was from this relatively hospitable base camp that the ALMA antenna began its journey to the high Chajnantor site. "The successful transport of the first ALMA Antenna to the high site marks the start of the next phase of the project. Now that we are starting to move the ALMA antennas to the high site, the real work begins and the exciting part is just beginning," said Adrian Russell, North American ALMA Project Manager. The antenna's trip began when one of the two ALMA transporters lifted the antenna onto its back, carrying its heavy load along the 17-mile road from the Operations Support Facility up to the Array Operations Site. While the transporter is capable of speeds of up to 8 miles per hour when carrying an antenna, this first journey was made more slowly to ensure that everything worked as expected, taking about seven hours. The ALMA antennas use state-of-the-art technology, and are the most advanced submillimeter-wavelength antennas ever made. They are designed to operate fully exposed in the harsh conditions of the Array Operations Site, to survive strong winds and extreme temperatures, to point precisely enough that they could pick out a golf

  11. The Advanced Technology Solar Telescope enclosure

    NASA Astrophysics Data System (ADS)

    Phelps, L.; Barr, J.; Dalrymple, N.; Fraser, M.; Hubbard, R.; Wagner, J.; Warner, M.

    2006-06-01

    Telescope enclosure design is based on an increasingly standard set of criteria. Enclosures must provide failsafe protection in a harsh environment for an irreplaceable piece of equipment; must allow effective air flushing to minimize local seeing while still attenuating wind-induced vibration of the telescope; must reliably operate so that the dome is never the reason for observatory down time; must provide access to utilities, lifting devices and support facilities; and they must be affordable within the overall project budget. The enclosure for the Advanced Technology Solar Telescope (ATST) has to satisfy all these challenging requirements plus one more. To eliminate so-called external dome seeing, the exterior surfaces of the enclosure must be maintained at or just below ambient air temperature while being subjected to the full solar loading of an observing day. Further complicating the design of the ATST enclosure and support facilities are the environmental sensitivities and high construction costs at the selected site - the summit of Haleakala on the island of Maui, Hawaii. Previous development work has determined an appropriate enclosure shape to minimize solar exposure while allowing effective interior flushing, and has demonstrated the feasibility of controlling the exterior skin temperature with an active cooling system. This paper presents the evolution of the design since site selection and how the enclosure and associated thermal systems have been tailored to the particular climatic and terrain conditions of the site. Also discussed are load-reduction strategies that have been identified through thermal modeling, CFD modeling, and other analyses to refine and economize the thermal control systems.

  12. Wind buffeting of large telescopes.

    PubMed

    MacMynowski, Douglas G; Andersen, Torben

    2010-02-01

    Unsteady wind loads due to turbulence within the telescope enclosure are one of the largest dynamic disturbances for ground-based optical telescopes. The desire to minimize the response to the wind influences the design of the telescope enclosure, structure, and control systems. There is now significant experience in detailed integrated modeling to predict image jitter due to wind. Based on this experience, a relatively simple model is proposed that is verified (from a more detailed model) to capture the relevant physics. In addition to illustrating the important elements of the telescope design that influence wind response, this model is used to understand the sensitivity of telescope image jitter to a wide range of design parameters.

  13. UKIRT Upgrades Program: control of the telescope thermal environment

    NASA Astrophysics Data System (ADS)

    Cavedoni, Charles P.; Hawarden, Timothy G.; Chuter, Timothy C.; Look, I. A.

    1997-03-01

    The control of the telescope thermal environment at the 3.8-m United Kingdom Infrared Telescope (UKIRT) is based on the requirements that dome seeing should not degrade the image quality by more than 0.05 arcsec (FWHM) and that mirror seeing should be reduced to negligible proportions. After quantifying steady state and transient heat flow around and through the building, we set out on a program to meet these requirements. Major telescope enclosure upgrades to address dome seeing include natural dome ventilation with 16 apertures in the base of the dome and for near still-air nights, forced-air ventilation via the plant room exhaust system. To address mirror seeing, we are in the process of installing a day-time mirror cooling system that can drive and/or keep the primary mirror between 0 degrees Celsius and 2.5 degrees Celsius colder than the predicted night-time local dome air temperature. Nevertheless, during the night, if the primary mirror is warmer than the local dome air, a flushing system is available to blow away warm convective air cells as they form. This paper describes design considerations of the natural dome ventilation system (DVS), the hardware of the primary mirror cooling and flushing system and the performance of the mirror flushing system on a dummy mirror segment.

  14. Development of a Low Cost Telescope System for VHE Astronomy

    NASA Astrophysics Data System (ADS)

    Querrard, Rodney; Perkins, Jeremy S.

    2017-01-01

    Ground based gamma-ray astronomy has progressed dramatically over the past 40 years. Currently there are 176 confirmed sources detected above 100 GeV ranging from Supernova Remnants (SNR) to Active Galaxies and other objects The next generation of Imaging Air Cherenkov Telescopes (IACT) is currently being developed. The CTA, or Cherenkov Telescope Array, will be a ground-breaking facility made up of a few dozen telescopes of multiple sizes with a sensitivity an order of magnitude greater than the current generation. Nevertheless, an opportunity will remain for smaller, less-expensive instruments to make important contributions to the field of Cherenkov Imaging astronomy.We are investigating an approach that will use an inexpensive array of ground based telescopes built from commercial-off-the-shelf (COTS) products. This array will be capable of studying supernova remnants, gamma-ray-burst afterglows, and active galactic nuclei as well as other sources above 2 TeV at a cost which is much lower than larger facilities like the CTA. We are developing a single prototype telescope that will be installed at the Goddard Geophysical and Astronomical Observatory in Greenbelt, MD. We discuss issues arising from and technical solutions to challenges of using COTS components whose primary purpose is not astronomy for this application. We detail progress in the telescope development and outline future work to complete the prototype and to duplicate it for creation of a low-cost Cherenkov array.

  15. Seismic Imager Space Telescope

    NASA Technical Reports Server (NTRS)

    Sidick, Erkin; Coste, Keith; Cunningham, J.; Sievers,Michael W.; Agnes, Gregory S.; Polanco, Otto R.; Green, Joseph J.; Cameron, Bruce A.; Redding, David C.; Avouac, Jean Philippe; Ampuero, Jean Paul; Leprince, Sebastien; Michel, Remi

    2012-01-01

    A concept has been developed for a geostationary seismic imager (GSI), a space telescope in geostationary orbit above the Pacific coast of the Americas that would provide movies of many large earthquakes occurring in the area from Southern Chile to Southern Alaska. The GSI movies would cover a field of view as long as 300 km, at a spatial resolution of 3 to 15 m and a temporal resolution of 1 to 2 Hz, which is sufficient for accurate measurement of surface displacements and photometric changes induced by seismic waves. Computer processing of the movie images would exploit these dynamic changes to accurately measure the rapidly evolving surface waves and surface ruptures as they happen. These measurements would provide key information to advance the understanding of the mechanisms governing earthquake ruptures, and the propagation and arrest of damaging seismic waves. GSI operational strategy is to react to earthquakes detected by ground seismometers, slewing the satellite to point at the epicenters of earthquakes above a certain magnitude. Some of these earthquakes will be foreshocks of larger earthquakes; these will be observed, as the spacecraft would have been pointed in the right direction. This strategy was tested against the historical record for the Pacific coast of the Americas, from 1973 until the present. Based on the seismicity recorded during this time period, a GSI mission with a lifetime of 10 years could have been in position to observe at least 13 (22 on average) earthquakes of magnitude larger than 6, and at least one (2 on average) earthquake of magnitude larger than 7. A GSI would provide data unprecedented in its extent and temporal and spatial resolution. It would provide this data for some of the world's most seismically active regions, and do so better and at a lower cost than could be done with ground-based instrumentation. A GSI would revolutionize the understanding of earthquake dynamics, perhaps leading ultimately to effective warning

  16. High resolution imaging with multilayer telescopes: resolution performance of the MSSTA II telescopes

    SciTech Connect

    Martinez-Galarce, Dennis S.; Walker, Arthur B. C. II; Gore, David B.; Kankelborg, Charles C.; Hoover, Richard B.; Barbee, T. W. Jr.; Boerner, P. F. X.

    2000-04-01

    The Multi-Spectral Solar Telescope Array (MSSTA) is a sounding rocket-borne observatory composed of a set of normal-incidence multilayer-coated telescopes that obtained selected bandpass spectroheliograms (44 to 1550 Aa) of the solar atmosphere. These spectroheliograms were recorded on specially fabricated XUV and FUV 70-mm Kodak film. Rocket launches of this instrument payload took place in 1991 (MSSTA I) and 1994 (MSSTA II) at the White Sands Missile Test Range in New Mexico, sponsored by the National Aeronautics and Space Administration (NASA) sounding rocket experiment program. Immediately prior to the 1994 launch, visible light focusing tests of each telescope were performed in situ using a 1951 standard Air Force high-resolution test target, to measure optical resolution performance. We determined that the MSSTA II telescopes performed at diffraction-limited resolutions down to 0.70 arcsec at visible wavelengths. Based on these measurements, we calculate an upper bound to the focusing errors that incorporate the sum of all uncorrelated system focus errors that affect resolution performance. Coupling these upper bound estimates with the in-band diffraction limits, surface scattering errors and payload pointing jitter, we demonstrate that 11 of 19 MSSTA II telescopes--having negligible figures of focus errors in comparison to the corresponding visible diffraction limits--performed at sub arcsecond resolution at their operational FUV/EUV/XUV wavelengths during flight. We estimate the in-band performance down to 0.14{+-}0.08 arcsec. (c) 2000 Society of Photo-Optical Instrumentation Engineers.

  17. SOFIA: Flying the Telescope

    NASA Technical Reports Server (NTRS)

    Asher, Troy; Cumming, Steve

    2012-01-01

    The Stratospheric Observatory For Infrared Astronomy (SOFIA) is an international cooperative development and operations program between the United States National Aeronautics and Space Administration (NASA) and the German Space Agency, DLR (Deutsches Zentrum fuer Luft-und Raumfahrt). SOFIA is a 2.5 meter, optical/infrared/sub-millimeter telescope mounted in a Boeing model 747SP-21 aircraft and will be used for many basic astronomical observations performed at stratospheric altitudes. It will accommodate installation of different focal plane instruments with in-flight accessibility provided by investigators selected from the international science community. The Facility operational lifetime is planned to be greater than 20 years. This presentation will present the results of developmental testing of SOFIA, including analysis, envelope expansion and the first operational mission. It will describe a brief history of open cavities in flight, how NASA designed and tested SOFIAs cavity, as well as flight test results. It will focus on how the test team achieved key milestones by systematically and efficiently reducing the number of test points to only those absolutely necessary to achieve mission requirements, thereby meeting all requirements and saving the potential loss of program funding. Finally, it will showcase examples of the observatory in action and the first operational mission of the observatory, illustrating the usefulness of the system to the international scientific community. Lessons learned on how to whittle a mountain of test points into a manageable sum will be presented at the conclusion.

  18. Astronomy with Small Telescopes

    NASA Astrophysics Data System (ADS)

    Paczyński, Bohdan

    2006-12-01

    The All Sky Automated Survey is monitoring the entire sky to about 14 mag with a cadence of about 1 day; it has discovered about 105 variable stars, most of them new. The instrument used for the survey had an aperture of 7 cm. A search for planetary transits has led to the discovery of about a dozen confirmed planets, so-called hot Jupiters, providing information on planetary masses and radii. Most discoveries were done with telescopes with apertures of 10 cm. We propose a search for optical transients covering the entire sky with a cadence of 10-30 minutes and a limit of 12-14 mag, with an instant verification of all candidate events. The search will be made with a large number of 10 cm instruments, and the verification will be done with 30 cm instruments. We also propose a system to be located at the L1 point of the Earth-Sun system to detect ``killer asteroids.'' With a limiting magnitude of about 18 mag, it could detect 10 m boulders several hours prior to their impact and provide warning against Tunguska-like events, as well as provide news about spectacular but more modest, harmless impacts.

  19. Astronomy with Small Telescopes

    NASA Astrophysics Data System (ADS)

    Paczynski, Bohdan

    2006-06-01

    While there are more than a dozen telescopes larger than 10 meters there is plenty of interesting astronomy which can be done with much smaller instruments. Notice that the existing SDSS, and the future PanSTARRS and LSST saturate at 15 mag. An example of interesting science is provided with ASAS (All Sky Automated Survey) which used aperture of 7 cm to discover over 50,000 variable stars brighter than 14 mag, covering almost 3/4 of the sky. Most of these are new discoveries.ASAS like instruments are most likely more efficient in a search for afterglows following gamma-ray bursts (GRB) than CFHT and its Megacam. In fact it should be possible to detect the afterglows without a GRB trigger by imaging all visible sky every 15 minutes down to 16 mag using a number of ASAS-like instruments.Another example of small instruments being essential, is their ability to detect 'killer asteroids' prior to their impact. It will take a number of small instruments, somewhat more powerful than ASAS, to detect boulders as small as 10 - 20 meters at a distance of several days prior to their impact. This will provide time to evacuate a region in case of Tunguska-like event, or to provide news of a spectacular but harmless event in case of a more modest impact.

  20. POST: Polar Stratospheric Telescope

    NASA Astrophysics Data System (ADS)

    Bely, Pierre Y.; Ford, Holland C.; Burg, Richard; Petro, Larry; White, Rick; Bally, John

    1995-10-01

    The tropopause, typically at 16 to 18 km altitude at the lower latitudes, dips to 8 km in the polar regions. This makes the cold, dry and nonturbulent lower stratosphere accessible to tethered aerostats. Tethered aerostats can fly as high as 12 km and are extremely reliable, lasting for many years. In contrast to free-flying balloons, they can stay on station for weeks at a time, and payloads can be safely recovered for maintenance and adjustment and relaunched in a matter of hours. We propose to use such a platform, located first in the Arctic (near Fairbanks, Alaska) and, potentially, later in the Antarctic, to operate a new technology 6-meter, diluted aperture telescope with diffraction-limited performance in the near infrared. Thanks to the low ambient temperature (220 K), thermal emission from the optics is of the same order as that of the zodiacal light in the 2 to 3 micron band. Since this wavelength interval is the darkest part of the zodiacal light spectrum from optical wavelengths to 100 microns, the combination of high resolution images and a very dark sky make it the spectral region of choice for observing the redshifted light from galaxies and clusters of galaxies at moderate to high redshifts.

  1. A new search for primordial black hole evaporations using the Whipple gamma-ray telescope

    NASA Astrophysics Data System (ADS)

    Linton, E. T.; Atkins, R. W.; Badran, H. M.; Blaylock, G.; Boyle, P. J.; Buckley, J. H.; Byrum, K. L.; Carter-Lewis, D. A.; Celik, O.; Chow, Y. C. K.; Cogan, P.; Daniel, M. K.; Dowdall, C.; Falcone, A. D.; Fegan, D. J.; Fegan, S. J.; Finley, J. P.; Fortin, P.; Guiterrez, K. J.; Hall, J.; Hanna, D.; Holder, J.; Horan, D.; Hughes, S. B.; Humensky, T. B.; Jung, I.; Kenny, G. E.; Kertzman, M.; Kieda, D. B.; Kildea, J.; Knapp, J.; Krawczynski, H.; Lang, M. J.; LeBohec, S.; Maier, G.; Moriarty, P.; Ong, R. A.; Perkins, J. S.; Pizlo, F.; Pohl, M.; Quinn, J.; Ragan, K.; Rebillot, P. F.; Reynolds, P. T.; Sembroski, G. H.; Steele, D.; Swordy, S. P.; Valcarcel, L.; Wakely, S. P.; Weekes, T. C.; White, R. J.

    2006-01-01

    Stephen Hawking's prediction that black holes should radiate like black bodies has several important consequences, including the possibility of the detection of small (~1015 g) black holes created in the very early universe. The detection of such primordial black holes (PBHs) would be an important discovery, not only confirming Hawking's theory, but also providing valuable insights into the history of the early universe. A search through 5.5 years of archival data from the Whipple Atmospheric Cerenkov Telescope is made for TeV gamma-ray bursts on 1, 3, and 5 s timescales. On the basis of a null result from this direct search for PBH evaporations, an upper limit of 1.08 × 106 pc-3 yr-1 (99% CL) is set on the PBH evaporation rate in the local region of the galaxy, assuming the Standard Model of particle physics. This is more than a factor of two better than the previous limit at this energy range and includes longer timescales than have previously been explored. Comparison of this result with previous limits on the fraction of the critical density comprised by PBHs, Ωpbh, depends strongly on assumptions made about PBH clustering; in models predicting strong PBH clustering, the limit in this work could be as many as ten orders of magnitude more stringently than those set by diffuse MeV gamma-ray observations.

  2. A stochastic model for photon noise induced by charged particles in multiplier phototubes of the space telescope fine guidance sensors

    NASA Technical Reports Server (NTRS)

    Howell, L. W.; Kennel, H. F.

    1984-01-01

    The Space Telescope (ST) is subjected to charged particle strikes in its space environment. ST's onboard fine guidance sensors utilize multiplier phototubes (PMT) for attitude determination. These tubes, when subjected to charged particle strikes, generate spurious photons in the form of Cerenkov radiation and fluorescence which give rise to unwanted disturbances in the pointing of the telescope. A stochastic model for the number of these spurious photons which strike the photocathode of the multiplier phototube which in turn produce the unwanted photon noise are presented. The model is applicable to both galactic cosmic rays and charged particles trapped in the Earth's radiation belts. The model which was programmed allows for easy adaption to a wide range of particles and different parameters for the phototube of the multiplier. The probability density functions for photons noise caused by protons, alpha particles, and carbon nuclei were using thousands of simulated strikes. These distributions are used as part of an overall ST dynamics simulation. The sensitivity of the density function to changes in the window parameters was also investigated.

  3. Stochastic model for photon noise induced by charged particles in multiplier phototubes of the Hubble Space Telescope fine guidance sensors

    NASA Technical Reports Server (NTRS)

    Howell, L. W.; Kennel, H. F.

    1986-01-01

    The Space Telescope (ST) is subjected to charged particle strikes in its space environment. ST's onboard fine guidance sensors utilize multiplier phototubes (PMT) for attitude determination. These tubes, when subjected to charged particle strikes, generate spurious photons in the form of Cerenkov radiation and fluorescence which give rise to unwanted disturbances in the pointing of the telescope. A stochastic model for the number of these spurious photons which strike the photocathodes of the multiplier phototube which in turn produce the unwanted photon noise are presented. The model is applicable to both galactic cosmic rays and charged particles trapped in the earth's radiation belts. The model which was programmed allows for easy adaption to a wide range of particles and different parameters for the phototube of the multiplier. The probability density functions for photons noise caused by protons, alpha particles, and carbon nuclei were using thousands of simulated strikes. These distributions are used as part of an overall ST dynamics simulation. The sensitivity of the density function to changes in the window parameters was also investigated.

  4. Operating a heterogeneous telescope network

    NASA Astrophysics Data System (ADS)

    Allan, Alasdair; Bischoff, Karsten; Burgdorf, Martin; Cavanagh, Brad; Christian, Damien; Clay, Neil; Dickens, Rob; Economou, Frossie; Fadavi, Mehri; Frazer, Stephen; Granzer, Thomas; Grosvenor, Sandy; Hessman, Frederic V.; Jenness, Tim; Koratkar, Anuradha; Lehner, Matthew; Mottram, Chris; Naylor, Tim; Saunders, Eric S.; Solomos, Nikolaos; Steele, Iain A.; Tuparev, Georg; Vestrand, W. Thomas; White, Robert R.; Yost, Sarah

    2006-06-01

    In the last few years the ubiquitous availability of high bandwidth networks has changed the way both robotic and non-robotic telescopes operate, with single isolated telescopes being integrated into expanding "smart" telescope networks that can span continents and respond to transient events in seconds. The Heterogeneous Telescope Networks (HTN)* Consortium represents a number of major research groups in the field of robotic telescopes, and together we are proposing a standards based approach to providing interoperability between the existing proprietary telescope networks. We further propose standards for interoperability, and integration with, the emerging Virtual Observatory. We present the results of the first interoperability meeting held last year and discuss the protocol and transport standards agreed at the meeting, which deals with the complex issue of how to optimally schedule observations on geographically distributed resources. We discuss a free market approach to this scheduling problem, which must initially be based on ad-hoc agreements between the participants in the network, but which may eventually expand into a electronic market for the exchange of telescope time.

  5. Space Telescope Systems Description Handbook

    NASA Technical Reports Server (NTRS)

    Carter, R. E.

    1985-01-01

    The objective of the Space Telescope Project is to orbit a high quality optical 2.4-meter telescope system by the Space Shuttle for use by the astronomical community in conjunction with NASA. The scientific objectives of the Space Telescope are to determine the constitution, physical characteristics, and dynamics of celestial bodies; the nature of processes which occur in the extreme physical conditions existing in stellar objects; the history and evolution of the universe; and whether the laws of nature are universal in the space-time continuum. Like ground-based telescopes, the Space Telescope was designed as a general-purpose instrument, capable of utilizing a wide variety of scientific instruments at its focal plane. This multi-purpose characteristic will allow the Space Telescope to be effectively used as a national facility, capable of supporting the astronomical needs for an international user community and hence making contributions to man's needs. By using the Space Shuttle to provide scientific instrument upgrading and subsystems maintenance, the useful and effective operational lifetime of the Space Telescope will be extended to a decade or more.

  6. Initial computational fluid dynamics modeling of the Giant Magellan Telescope site and enclosure

    NASA Astrophysics Data System (ADS)

    Danks, Ryan; Smeaton, William; Bigelow, Bruce; Burgett, William

    2016-08-01

    In the era of extremely large telescopes (ELTs), with telescope apertures growing in size and tighter image quality requirements, maintaining a controlled observation environment is critical. Image quality is directly influenced by thermal gradients, the level of turbulence in the incoming air flow and the wind forces acting on the telescope. Thus any ELT enclosure must be able to modulate the speed and direction of the incoming air and limit the inflow of disturbed ground-layer air. However, gaining an a priori understanding of the wind environment's impacts on a proposed telescope is complicated by the fact that telescopes are usually located in remote, mountainous areas, which often do not have high quality historic records of the wind conditions, and can be subjected to highly complex flow patterns that may not be well represented by the traditional analytic approaches used in typical building design. As part of the design process for the Giant Magellan Telescope at Cerro Las Campanas, Chile; the authors conducted a parametric design study using computational fluid dynamics which assessed how the telescope's position on the mesa, its ventilation configuration and the design of the enclosure and windscreens could be optimized to minimize the infiltration of ground-layer air. These simulations yielded an understanding of how the enclosure and the natural wind flows at the site could best work together to provide a consistent, well controlled observation environment. Future work will seek to quantify the aerothermal environment in terms of image quality.

  7. Why systems engineering on telescopes?

    NASA Astrophysics Data System (ADS)

    Swart, Gerhard P.; Meiring, Jacobus G.

    2003-02-01

    Although Systems Engineering has been widely applied to the defence industry, many other projects are unaware of its potential benefits when correctly applied, assuming that it is an expensive luxury. It seems that except in a few instances, telescope projects are no exception, prompting the writing of this paper. The authors postulate that classical Systems Engineering can and should be tailored, and then applied to telescope projects, leading to cost, schedule and technical benefits. This paper explores the essence of Systems Engineering and how it can be applied to any complex development project. The authors cite real-world Systems Engineering examples from the Southern African Large Telescope (SALT). The SALT project is the development and construction of a 10m-class telescope at the price of a 4m telescope. Although SALT resembles the groundbreaking Hobby-Eberly Telescope (HET) in Texas, the project team are attempting several challenging changes to the original design, requiring a focussed engineering approach and discernment in the definition of the telescope requirements. Following a tailored Systems Engineering approach on this project has already enhanced the quality of decisions made, improved the fidelity of contractual specifications for subsystems, and established criteria testing their performance. Systems Engineering, as applied on SALT, is a structured development process, where requirements are formally defined before the award of subsystem developmental contracts. During this process conceptual design, modeling and prototyping are performed to ensure that the requirements were realistic and accurate. Design reviews are held where the designs are checked for compliance with the requirements. Supplier factory and on-site testing are followed by integrated telescope testing, to verify system performance against the specifications. Although the SALT project is still far from completion, the authors are confident that the present benefits from

  8. Kees Zwaan, open principle, future of high-resolution solar telescopes

    NASA Astrophysics Data System (ADS)

    Hammerschlag, R. H.; Bettonvil, F. C. M.

    2013-01-01

    It was around the 1970s that during site-test campaigns masts were erected up till 30 m height with sensors at several heights for the measurement of temperature fluctuations. Kees Zwaan discovered that the fluctuations decrease drastically at heights from about 15 m and upward when there is some wind. The conclusion from this experience was the open telescope principle: a telescope completely free in the air 15 m or more above the ground. The Dutch Open Telescope (DOT) was the pioneering demonstrator of the open-telescope technology. Now that larger high-resolution telescopes come in view, it is time to analyze again the principle: the essentials for proper working of the open principle and the design consequences for the new generation of high-resolution solar telescopes.

  9. Cornelis Zwaan, open principle, and the future of high-resolution solar telescopes

    NASA Astrophysics Data System (ADS)

    Hammerschlag, Robert H.; Bettonvil, Felix C. M.; Jägers, Aswin P. L.; Sliepen, Guus

    2008-07-01

    It was in the years around 1970 that during site-test campaigns for JOSO masts were erected up till 30 m height with sensors at several heights for the measurement of temperature fluctuations. Cornelis (Kees) Zwaan discovered that the fluctuations decrease drastically at heights from about 15 m and upward when there is some wind. The conclusion from this experience was the open telescope principle: the telescope should be completely free in the air 15 m or more above the ground. The Dutch Open Telescope (DOT) was the pioneering demonstrator of the open-telescope technology. Now that larger high-resolution telescopes come in view, it is time to analyze again the principle: (i) the essentials for proper working of the open principle; (ii) the differences with nighttime observations particularly concerning the seeing; (iii) the design consequences for the new generation of high-resolution solar telescopes.

  10. Geodetic Observatory Wettzell - 20-m Radio Telescope and Twin Telescope

    NASA Technical Reports Server (NTRS)

    Neidhardt, Alexander; Kronschnabl, Gerhard; Schatz, Raimund

    2013-01-01

    In the year 2012, the 20-m radio telescope at the Geodetic Observatory Wettzell, Germany again contributed very successfully to the International VLBI Service for Geodesy and Astrometry observing program. Technical changes, developments, improvements, and upgrades were made to increase the reliability of the entire VLBI observing system. In parallel, the new Twin radio telescope Wettzell (TTW) got the first feedhorn, while the construction of the HF-receiving and the controlling system was continued.

  11. Lightweighted ZERODUR for telescopes

    NASA Astrophysics Data System (ADS)

    Westerhoff, T.; Davis, M.; Hartmann, P.; Hull, T.; Jedamzik, R.

    2014-07-01

    The glass ceramic ZERODUR® from SCHOTT has an excellent reputation as mirror blank material for earthbound and space telescope applications. It is known for its extremely low coefficient of thermal expansion (CTE) at room temperature and its excellent CTE homogeneity. Recent improvements in CNC machining at SCHOTT allow achieving extremely light weighted substrates up to 90% incorporating very thin ribs and face sheets. In 2012 new ZERODUR® grades EXPANSION CLASS 0 SPECIAL and EXTREME have been released that offer the tightest CTE grades ever. With ZERODUR® TAILORED it is even possible to offer ZERODUR® optimized for customer application temperature profiles. In 2013 SCHOTT started the development of a new dilatometer setup with the target to drive the industrial standard of high accuracy thermal expansion metrology to its limit. In recent years SCHOTT published several paper on improved bending strength of ZERODUR® and lifetime evaluation based on threshold values derived from 3 parameter Weibull distribution fitted to a multitude of stress data. ZERODUR® has been and is still being successfully used as mirror substrates for a large number of space missions. ZERODUR® was used for the secondary mirror in HST and for the Wolter mirrors in CHANDRA without any reported degradation of the optical image quality during the lifetime of the missions. Some years ago early studies on the compaction effects of electron radiation on ZERODUR® were re analyzed. Using a more relevant physical model based on a simplified bimetallic equation the expected deformation of samples exposed in laboratory and space could be predicted in a much more accurate way. The relevant ingredients for light weighted mirror substrates are discussed in this paper: substrate material with excellent homogeneity in its properties, sufficient bending strengths, space radiation hardness and CNC machining capabilities.

  12. Its Cerenkov Radiation

    DTIC Science & Technology

    1989-12-01

    apec.f ’ed as aoproprlate combinations of te .rev.ous’_y defined bodies. Such cm inat= Ions ay be as simple as ust a sin.-e body, or they may consist...use a correct ion run to insert the necessary logic at the proper place near the end of Subroutine JOGN. The proper Location is commented in the...ave the producton position and electron beam direction. KFD etermine the Index of refraction for current wavelength bin Lsthe Cersinkov condition

  13. A proposal for a precision test of the standard model by neutrino-electron scattering (Large /hacek C/erenkov Detector Project)

    SciTech Connect

    Allen, R.C.; Lu, X-Q.; Gollwitzer, K.; Igo, G.J.; Gulmez, E.; Whitten, C.; VanDalen, G.; Layter, J.; Fung, Sun Yui; Shen, B.C.

    1988-04-01

    A precision measurement of neutrino-electron elastic scattering from a beam stop neutrino source at LAMPF is proposed. The total error in sin/sup 2/theta/sub W/ is estimated to be +-0.89/percent/. The experiment also will be sensitive to neutrino oscillations and supernova-neutrino bursts, and should set improved limits on the neutrino-charge radius and magnetic-dipole moment. The detector consists of a 2.5-million-gallon tank of water with approximately 14,000 photomultiplier tubes lining the surfaces of the tank. Neutrino-electron scattering events will be observed from the /hacek C/erenkov radiation emitted by the electrons in the water. 19 refs.

  14. Prism beamswitch for radio telescopes.

    PubMed

    Payne, J M; Ulich, B L

    1978-12-01

    A dielectric prism and switching mechanism have been constructed for beamswitching a Cassegrain radio telescope. Spatially extended radio sources may be mapped without significant confusion utilizing the sensitivity and stability inherent in the conventional Dicke radiometer.

  15. Automated telescope for variability studies

    NASA Astrophysics Data System (ADS)

    Ganesh, S.; Baliyan, K. S.; Chandra, S.; Joshi, U. C.; Kalyaan, A.; Mathur, S. N.

    PRL has installed a 50 cm telescope at Mt Abu, Gurushikhar. The backend instrument consists of a 1K × 1K EMCCD camera with standard UBVRI filters and also has polarization measurement capability using a second filter wheel with polaroid sheets oriented at different position angles. This 50 cm telescope observatory is operated in a robotic mode with different methods of scheduling of the objects being observed. This includes batch mode, fully manual as well as fully autonomous mode of operation. Linux based command line as well as GUI software are used entirely in this observatory. This talk will present the details of the telescope and associated instruments and auxiliary facilities for weather monitoring that were developed in house to ensure the safe and reliable operation of the telescope. The facility has been in use for a couple of years now and various objects have been observed. Some of the interesting results will also be presented.

  16. Anastigmatic three-mirror telescope

    NASA Technical Reports Server (NTRS)

    Korsch, D. G. (Inventor)

    1978-01-01

    A three-mirror telescope for extraterrestrial observations is described. An ellipsoidal primary mirror, a hyperbolic secondary mirror, and an ellipsoidal tertiary mirror, produce an image in a conveniently located finite plane for viewing.

  17. Space Telescope moving target tracking

    NASA Technical Reports Server (NTRS)

    Strikwerda, T. E.; Strohbehn, K.; Fowler, K. R.; Skillman, D. R.

    1985-01-01

    This paper formulates a Space Telescope (ST) moving target tracking algorithm and evaluates a practical implementation. The algorithm is shown to be satisfactory for tracking such moving objects as the moons of Mars.

  18. Large aperture Fresnel telescopes/011

    SciTech Connect

    Hyde, R.A., LLNL

    1998-07-16

    At Livermore we`ve spent the last two years examining an alternative approach towards very large aperture (VLA) telescopes, one based upon transmissive Fresnel lenses rather than on mirrors. Fresnel lenses are attractive for VLA telescopes because they are launchable (lightweight, packagable, and deployable) and because they virtually eliminate the traditional, very tight, surface shape requirements faced by reflecting telescopes. Their (potentially severe) optical drawback, a very narrow spectral bandwidth, can be eliminated by use of a second (much smaller) chromatically-correcting Fresnel element. This enables Fresnel VLA telescopes to provide either single band ({Delta}{lambda}/{lambda} {approximately} 0.1), multiple band, or continuous spectral coverage. Building and fielding such large Fresnel lenses will present a significant challenge, but one which appears, with effort, to be solvable.

  19. Hubble Space Telescope-Illustration

    NASA Technical Reports Server (NTRS)

    1989-01-01

    This illustration depicts a side view of the Hubble Space Telescope (HST). The HST is the product of a partnership between NASA, European Space Agency Contractors, and the international community of astronomers. It is named after Edwin P. Hubble, an American Astronomer who discovered the expanding nature of the universe and was the first to realize the true nature of galaxies. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The HST detects objects 25 times fainter than the dimmest objects seen from Earth and provides astronomers with an observable universe 250 times larger than visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The major elements of the HST are the Optical Telescope Assembly (OTA), the Support System Module (SSM), and the Scientific Instruments (SI). The HST is approximately the size of a railroad car, with two cylinders joined together and wrapped in a silvery reflective heat shield blanket. Wing-like solar arrays extend horizontally from each side of these cylinders, and dish-shaped anternas extend above and below the body of the telescope. The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Connecticut, developed the optical system and guidance sensors. The Lockheed Missile and Space Company of Sunnyvale, California produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope.

  20. The Large Binocular Telescope Project

    NASA Astrophysics Data System (ADS)

    Hill, J. M.

    1994-12-01

    The Large Binocular Telescope (LBT) Project has evolved from concepts first proposed in 1985. The present partners involved in the design and construction of this 2 x 8.4 meter binocular telescope are the University of Arizona, Italy represented by the Osservatorio Astronomico di Arcetri and the Research Corporation based in Tucson. These three partners have committed sufficient funds to build the enclosure and the telescope populated with a single 8.4 meter optical train --- approximately 40 million dollars (1989). Based on this commitment, design and construction activities are now moving forward. Additional partners are being sought. The next mirror to be cast at the Steward Observatory Mirror Lab in late fall 1995 will be the first borosilicate honeycomb primary for LBT. The baseline optical configuration of LBT includes wide field Cassegrain secondaries with optical foci above the primaries to provide a corrected one degree field at F/4. The infrared F/15 secondaries are a Gregorian design to allow maximum flexibility for adaptive optics. The F/15 secondaries are undersized to provide a low thermal background focal plane which is unvignetted over a 4 arcminute diameter field-of-view. The interferometric focus combining the light from the two 8.4 meter primaries will reimage two folded Gregorian focal planes to a central location. The telescope elevation structure accommodates swing arms which allow rapid interchange of the various secondary and tertiary mirrors. Maximum stiffness and minimal thermal disturbance continue to be important drivers for the detailed design of the telescope. The telescope structure accommodates installation of a vacuum bell jar for aluminizing the primary mirrors in-situ on the telescope. The detailed design of the telescope structure will be completed in 1995 by ADS Italia (Lecco) and European Industrial Engineering (Mestre). The final enclosure design is now in progress at M3 Engineering (Tucson) and ADS Italia. Construction

  1. The Large Binocular Telescope Project

    NASA Astrophysics Data System (ADS)

    Hill, J. M.

    1995-05-01

    The Large Binocular Telescope (LBT) Project has evolved from concepts first proposed in 1985. The present partners involved in the design and construction of this 2 x 8.4 meter binocular telescope are the University of Arizona, Italy represented by the Osservatorio Astrofisico di Arcetri and the Research Corporation based in Tucson. These three partners have committed sufficient funds to build the enclosure and the telescope populated with a single 8.4 meter optical train --- approximately 40 million dollars (1989). Based on this commitment, design and construction activities are now moving forward. Additional partners are being sought. The next mirror to be cast at the Steward Observatory Mirror Lab in spring of 1996 will be the first borosilicate honeycomb primary for LBT. The baseline optical configuration of LBT includes wide field Cassegrain secondaries with optical foci above the primaries to provide a corrected one degree field at F/4. The infrared F/15 secondaries are a Gregorian design to allow maximicrons flexibility for adaptive optics. The F/15 secondaries are undersized to provide a low thermal background focal plane which is unvignetted over a 4 arcminute diameter field-of-view. The interferometric focus combining the light from the two 8.4 meter primaries will reimage two folded Gregorian focal planes to a central location. The telescope elevation structure accommodates swing arms which allow rapid interchange of the various secondary and tertiary mirrors. Maximicrons stiffness and minimal thermal disturbance continue to be important drivers for the detailed design of the telescope. The telescope structure accommodates installation of a vacuum bell jar for aluminizing the primary mirrors in-situ on the telescope. The detailed design of the telescope structure will be completed in 1995 by ADS Italia (Lecco) and European Industrial Engineering (Mestre). The final enclosure design is now in progress at M3 Engineering (Tucson) and ADS Italia

  2. Hubble Space Telescope-Illustration

    NASA Technical Reports Server (NTRS)

    1986-01-01

    This is a cutaway illustration of the Hubble Space Telescope (HST) with callouts. The HST is the product of a partnership between NASA, European Space Agency Contractors, and the international community of astronomers. It is named after Edwin P. Hubble, an American Astronomer who discovered the expanding nature of the universe and was the first to realize the true nature of galaxies. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able collect data that is free of the Earth's atmosphere. The HST detects objects 25 times fainter than the dimmest objects seen from Earth and provides astronomers with an observable universe 250 times larger than visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The major elements of the HST are the Optical Telescope Assembly (OTA), the Support System Module (SSM), and the Scientific Instruments (SI). The HST is approximately the size of a railroad car, with two cylinders joined together and wrapped in a silvery reflective heat shield blanket. Wing-like solar arrays extend horizontally from each side of these cylinders, and dish-shaped anternas extend above and below the body of the telescope. The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Connecticut, developed the optical system and guidance sensors. The Lockheed Missile and Space Company of Sunnyvale, California produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope.

  3. Hubble Space Telescope-Concept

    NASA Technical Reports Server (NTRS)

    1986-01-01

    This is an artist's concept of the Hubble Space Telescope (HST). The HST is the product of a partnership between NASA, European Space Agency Contractors, and the international community of astronomers. It is named after Edwin P. Hubble, an American Astronomer who discovered the expanding nature of the universe and was the first to realize the true nature of galaxies. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The HST detects objects 25 times fainter than the dimmest objects seen from Earth and provides astronomers with an observable universe 250 times larger than is visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The major elements of the HST are the Optical Telescope Assembly (OTA), the Support System Module (SSM), and the Scientific Instruments (SI). The HST is approximately the size of a railroad car, with two cylinders joined together and wrapped in a silvery reflective heat shield blanket. Wing-like solar arrays extend horizontally from each side of these cylinders, and dish-shaped anternas extend above and below the body of the telescope. The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Connecticut, developed the optical system and guidance sensors. The Lockheed Missile and Space Company of Sunnyvale, California produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope.

  4. BCK Network of Optical Telescopes

    NASA Astrophysics Data System (ADS)

    McGruder, Charles H.; Antoniuk, Krill; Carini, Michael T.; Gelderman, Richard; Hammond, Benjamin; Hicks, Stacy; Laney, David; Shakhovskoy, David; Strolger, Louis-Gregory; Williams, Joshua

    2015-01-01

    The BCK network consists of three research grade telescopes: 0.6m (B) at the Bell Observatory near Western Kentucky University (WKU), 1.3m (C) at the Crimean Astrophysical Observatory and a 1.3m (K) at Kitt Peak National Observatory. The Bell Telescope is operated remotely from WKU while the Robotically Controlled Telescope (RCT) at Kitt Peak possesses an autonomous scheduler. The BCK telescopes are distributed longitudinally over 145º and can be used to observe continuously up to 21.2 hours/day. The network will be chiefly employed to observe variable stars, blazars and unpredictable celestial events.Because celestial objects with ground-based telescopes cannot be observed optically during the daytime, continuous ground-based astronomical observations are only possible via a network of longitudinally distributed telescopes. When the sun rises in Crimea after it sets at Bell, continuous observations are possible. This occurs for about six and ½ months per year - mid September to early April. A network is highly desirable for events that are not predictable for instance the appearance of supernovae, gamma-ray bursts, or undiscovered exoplanetsVariable stars are really only known in significant numbers to about 14 mag. But, as the magnitude increases the number of stars in any field increases very sharply, so there are many variable stars to discover at faint magnitude (m > 14). Discovering new variables makes great undergraduate student projects, a major component of astronomical research at WKU. In addition, pinning down the periods of variable stars is greatly facilitated with a network of telescopes.The BCK telescope network will also be used for monitoring the optical variability of blazars. The network provides increased coverage on daily variability timescales by minimizing interruptions due to weather and or mechanical problems at any one observatory and is used for obtaining continuous (12+ hours) of observations of rapid variability in blazars which would

  5. FalconSAT-7: a membrane space solar telescope

    NASA Astrophysics Data System (ADS)

    Andersen, Geoff; Asmolova, Olha; McHarg, Matthew G.; Quiller, Trey; Maldonado, Carlos

    2016-07-01

    The US Air Force Academy of Physics has built FalconSAT-7, a membrane solar telescope to be deployed from a 3U CubeSat in LEO. The primary optic is a 0.2m photon sieve - a diffractive element consisting of billions of tiny circular dimples etched into a Kapton sheet. The membrane its support structure, secondary optics, two imaging cameras and associated control, recording electronics are packaged within half the CubeSat volume. Once in space the supporting pantograph structure is deployed, extending out and pulling the membrane flat under tension. The telescope will then be directed at the Sun to gather images at H-alpha for transmission to the ground. We will present details of the optical configuration, operation and performance of the flight telescope which has been made ready for launch in early 2017.

  6. Limits on Lyot coronagraphy with AEOS adaptive optics telescope

    NASA Astrophysics Data System (ADS)

    Sivaramakrishnan, A.; Makidon, R. B.; Lloyd, J. P.; Oppenheimer, B. R.; Graham, J. R.; Kalas, P. G.; Macintosh, B. A.; Max, C. E.; Baudoz, P.; Kuhn, J.; Potter, D.

    2001-05-01

    The 3.6m Air Force Electo-Optical System telescope is the most advanced adaptive optics (AO) system available to the astronomical community. Its 941-channel AO system feeds several stable instrument platforms at a very slow Cassegrain focus. Its small secondary obscuration makes it ideal for AO coronagraphy. We present estimates of current and theoretical limits on dynamic range using a diffraction-limited Lyot coronagraph optimized for the 3.6m AEOS telescope. We incorporate both the effects of imperfect AO correction of the wavefront and telescope guiding errors in our simulations. We calculate limits on faint companion detection (in the H-band) for this system at separations between 0.36 and 1.3 arcseconds.

  7. Demonstration Telescopes Using "Dollar Optics"

    NASA Astrophysics Data System (ADS)

    Ross, Paul

    2008-05-01

    I propose a poster that illustrates the use of "dollar optics” for experimentation and for the creation of demonstration telescopes. Handling a variety of lenses and mirrors provides an opportunity for discovering practical optics. Some part of this path of exploration must have been traveled by Galileo as he experimented with spectacle lenses. "Dollar optics” include reading glasses (positive meniscus lenses), convex and concave mirrors, Fresnel sheets, magnifying lenses, and eye loupes. Unwanted distance spectacles (negative meniscus lenses) are available at second-hand stores. Galileo telescopes, "long” 17th century telescopes, and useful demonstration models of Newtonian reflectors can be made with "dollar” optics. The poster will illustrate practical information about "dollar optics” and telescopes: magnification, focal length, and "diopters” disassembling spectacles; creating cheap mounts for spectacle lenses; the importance of optical axes and alignment; eyepieces; and focusing. (A table would be useful with the poster to set out a hands-on display of "dollar optic” telescopes.) Educators, experimenters, and those concerned with astronomy outreach might be interested in this poster. Working with "dollar optics” requires facility with simple tools, interest in planning projects, patience, imagination, and the willingness to invest some time and effort. "Dollar optics” may help to foster creativity and hands-on enthusiasm - as did Galileo's work with simple lenses 400 years ago. "Oh! When will there be an end put to the new observations and discoveries of this admirable instrument?” - Galileo Galilei as quoted by Henry C. King, The History of the Telescope.

  8. SLAS Library Telescope Program (Abstract)

    NASA Astrophysics Data System (ADS)

    Small, J. S.

    2016-12-01

    (Abstract only) In the fall of 2014, I submitted to the members of the St. Louis Astronomical Society to take the $1,000 profit we had from a convention we had hosted and use it to purchase three telescopes to modify for a Library Telescope program that was invented by Mark Stowbridge and promoted by the New Hampshire Astronomical Society. I had met Mark at NEAF in 2012 when he was walking the floor demonstrating the telescope. We held meetings with three libraries, the St. Louis County Library system, the St. Louis Public Library system and an independent library in Kirkwood, Missouri. The response was overwhelming! SLCL responded with a request for ten telescopes and SLPL asked for five. We did our first build in October, 2014 and placed a total of eighteen telescopes. Since that time, SLAS has placed a total of eighty-eight telescopes in library systems around the St. Louis Metro area, expanding into neighboring counties and across the river in Illinois. In this talk, I will discuss how to approach this project and put it in place in your libraries!

  9. Concept Design for SOAR Telescope

    NASA Astrophysics Data System (ADS)

    Sebring, T.; Cecil, G.; Krabbendam, V.; Moretto, G.

    1998-12-01

    The Southern Astrophysical Research (SOAR) telescope is a \\$28M collaboration between Brazil, NOAO, Michigan State University, and the University of North Carolina at Chapel Hill. NOAO will operate the telescope for 20 years in exchange for 30 astronomers.) The project is now fully funded. This f/16 telescope is optimized for high-quality images across the isokinetic field (0."17 FWHM degradation from the telescope+facility over a field of 7.5' diameter.) It is being designed to take up to 2 Gemini-class (2100 kg) instruments, or a combination of lighter instruments at 7 Nasmyth and bent Cassegrain foci. The facility is now under construction atop Cerro Pachon, 400m from Gemini-S. First light is currently scheduled for early 2002. Corning Inc. is preparing to fabricate the 4.2m-diameter, 7.5-10 cm thick primary mirror from ULE glass. In early 1999 contacts will be awarded for 2 major subsystems: active optics (which includes optics polishing), and the alt.-az. telescope mount. We will outline the novel strategies that are being used to control project costs while optimizing telescope performance. Instrumentation plans will also be summarized.

  10. Education and outreach using the falcon telescope network

    NASA Astrophysics Data System (ADS)

    Gresham, Kimberlee C.; Palma, Christopher; Polsgrove, Daniel E.; Chun, Francis K.; Della-Rose, Devin J.; Tippets, Roger D.

    2016-12-01

    The Falcon Telescope Network (FTN) is a global network of small aperture telescopes developed by the Center for Space Situational Awareness Research in the Department of Physics at the United States Air Force Academy (USAFA). Consisting of commercially available equipment, the FTN is a collaborative effort between USAFA and other educational institutions ranging from two- and four-year colleges to major research universities. USAFA provides the equipment (e.g. telescope, mount, camera, filter wheel, dome, weather station, computers and storage devices) while the educational partners provide the building and infrastructure to support an observatory. The user base includes USAFA along with K-12 and higher education faculty and students. The diversity of the users implies a wide variety of observing interests, and thus the FTN collects images on diverse objects, including satellites, galactic and extragalactic objects, and objects popular for education and public outreach. The raw imagery, all in the public domain, will be accessible to FTN partners and will be archived at USAFA. Currently, there are five Falcon telescopes installed, two in Colorado and one each in Pennsylvania, Chile, and Australia. These five telescopes are in various stages of operational capability but all are remotely operable via a remote desktop application. The FTN team has conducted STEM First Light Projects for three of the U.S. observatories, soliciting proposals from middle and high school students and teachers that suggest and then become what is observed as official STEM first-light objects. Students and teachers learn how to write and submit a proposal as well as how telescopes operate and take data, while university-level students at the U.S. Air Force Academy and The Pennsylvania State University learn how to evaluate proposals and provide feedback to the middle and high school students and teachers. In this paper, we present the current status of the FTN, details of and lessons

  11. SOFIA: Flying the Telescope

    NASA Technical Reports Server (NTRS)

    Asher, Troy A.; Cumming, Stephen B.

    2012-01-01

    and a proof of concept mission for which SOFIA was opportunely positioned is showcased. Success on this time-critical mission to observe a rare astronomical event proved the usefulness of an airborne observatory and the value in waiting for the capability provided by SOFIA. Finally, lessons learned in the test program are presented with emphasis on how lessons from previous aircraft and successful test programs were applied to SOFIA. Effective application of these lessons was crucial to the success of the SOFIA flight test program. SOFIA is an international cooperative program between NASA and the German Space Agency, DLR. It is a 2.5 meter (100-inch) telescope mounted in a Boeing 747SP aircraft used for astronomical observations at altitudes above 35,000 feet. SOFIA will accommodate a host of scientific instruments from the international science community and has a planned operational lifespan of more than 20 years.

  12. Interferometers Sharpen Measurements for Better Telescopes

    NASA Technical Reports Server (NTRS)

    2013-01-01

    Over the last decade, there have been a number of innovations that have made possible the largest and most powerful telescope of its time: the James Webb Space Telescope (JWST). Scheduled to launch in 2018, JWST will provide insight into what the oldest, most distant galaxies look like. When engineers build a first-of-its-kind instrument like the JWST, they often must make new tools to construct the new technology. Throughout the decades of planning, development, and construction of the JWST, NASA has worked with numerous partners to spur innovations that have enabled the telescope s creation. Though the JWST s launch date is still several years away, a number of these innovations are spinning off to provide benefits here on Earth. One of these spinoffs has emerged from the extensive testing the JWST must undergo to ensure it will function in the extreme environment of space. In order to test the JWST instruments in conditions that closely resemble those in space, NASA uses a cryogenic vacuum chamber. By dropping the temperatures down to -400 F and employing powerful pumps to remove air from the chamber, engineers can test whether the JWST instruments will function once the spacecraft leaves Earth. Traditionally, a phase-shifting interferometer is used to measure optics like the JWST s mirrors to verify their precise shape, down to tens of nanometers, during manufacturing. However, the large size of the mirrors, coupled with vibration induced by the cryo-pumps, prohibits the use of traditional phase-shifting interferometers to measure the mirrors within the chamber environment. Because the JWST will be located in deep space, far from any possible manned service mission, it was essential to find a robust solution to guarantee the performance of the mirrors.

  13. The Carlsberg Meridian Telescope: an astrometric robotic telescope

    NASA Astrophysics Data System (ADS)

    Evans, D. W.

    2001-12-01

    An overview is given of the Carlsberg Meridian Telescope on La Palma, which is one of the oldest robotic telescopes, having started observing on La Palma in 1984. In the spring of 1997, a further stage of automation was made when we converted the telescope to remote operation. Since then, the telescope has been operated over the Internet from Britain, Denmark or Spain. In 1997, a CCD camera, operating in a drift-scan mode, was installed. A year later the telescope underwent a major upgrade and a larger 2k×2k CCD camera was installed, with a Sloan r' filter. With the new system, the magnitude limit is r'=17 and the positional accuracy is in the range 0.03'' to 0.05''. The main task of the project is to map the sky in the declination range -3o to +50o, with the aim of providing an astrometric and photometric catalogue that can accurately transfer the Hipparcos/Tycho reference frame to Schmidt plates. We will release the first data by the end of 2001. Using the photometric information, extinction data for La Palma is also provided.

  14. The Carlsberg Meridian Telescope: An Astrometric Robotic Telescope

    NASA Astrophysics Data System (ADS)

    Evans, Dafydd Wyn

    An overview is given of the Carlsberg Meridian Telescope on La Palma, which is one of the oldest robotic telescopes, having started observing in 1984. In the spring of 1997, a further stage of automation was made when we converted the telescope to remote operation. Since then, the telescope has been operated over the Internet from Britain, Denmark or Spain. Two years ago, the telescope underwent a major upgrade and a 2k×2k CCD camera was installed, with a Sloan r' filter, operating in a drift scan mode. With the new system, the magnitude limit is r'=17 and the positional accuracy is in the range 0.03'' to 0.05''. The main task of the project is to map the sky in the declination range -3o to +50o, with the aim of providing an astrometric and photometric catalogue that can accurately transfer the Hipparcos/Tycho reference frame to Schmidt plates. We will release the first data by the end of the year.

  15. James Webb Space Telescope: large deployable cryogenic telescope in space

    NASA Astrophysics Data System (ADS)

    Lightsey, Paul A.; Atkinson, Charles; Clampin, Mark; Feinberg, Lee D.

    2012-01-01

    The James Webb Space Telescope (JWST) is an infrared space telescope designed to explore four major science themes: first light and reionization, the assembly of galaxies, the birth of stars and protoplanetary systems, and planetary systems and origins of life. JWST is a segmented architecture telescope with an aperture of 6.6 m. It will operate at cryogenic temperature (40 K), achieved via passive cooling, in an orbit about the Earth-Sun second Lagrange point (L2). Passive cooling is facilitated by means of a large sunshield that provides thermal isolation and protection from direct illumination from the Sun. The large size of the telescope and spacecraft systems require that they are stowed for launch in a configuration that fits the Ariane 5 fairing, and then deployed after launch. Routine wavefront sensing and control measurements are used to achieve phasing of the segmented primary mirror and initial alignment of the telescope. A suite of instruments will provide the capability to observe over a spectral range from 0.6- to 27-μm wavelengths with imaging and spectroscopic configurations. An overview is presented of the architecture and selected optical design features of JWST are described.

  16. Site testing for the Discovery Channel Telescope

    NASA Astrophysics Data System (ADS)

    Bida, Thomas A.; Dunham, Edward W.; Bright, Leonard P.; Corson, Charles

    2004-10-01

    We present results of an extended campaign to test astronomical and environmental qualities of the intended site for the Discovery Channel Telescope, located at 2361m elevation near Happy Jack, AZ. A semi-permanent test station has been in operation since January 2003, consisting of a Differential Image Motion Measurement (DIMM) system and a weather station. Median seeing derived from DIMM measurements for January 2003 - May 2004 on 117 separate nights was 0.84 arcsec, with a first-quartile average of 0.62 arcsec. A wind sensor array deployed on a 12.2m tower is used to characterize air flow over the site. We find that ground induced turbulence becomes more prevalent below the 7.3m level. The Lowell DIMM system has also been run adjacent to the WIYN telescope for simultaneous comparative seeing measurements. Absolute correlations of DIMM seeing with WIYN image quality were good over two nights' observing under a range of environmental conditions.

  17. Large-Aperture, Three Mirror Telescopes for Near-Earth

    NASA Astrophysics Data System (ADS)

    Ackermann, M.; McGraw, J.

    In this era when Space Situational Awareness (SSA) is a national priority and optical-infrared telescopic sensor development is underway, cost-benefit analyses of competing approaches are necessary and appropriate. The DOD is presently investing in a new three-mirror telescope for SSA. At the same time, the Air Force, various universities and private research organizations are either studying or building wide-field telescopes with similar capabilities, but in most cases, at a significantly lower cost. Much of the expense for the DOD system appears driven by certain design choices which were advertised as necessary to fulfill the mission. Design details which would allow an independent analysis have not been published and no public comparison with other approaches is known to exist. Most telescope designs however, can be closely approximated from their optical configuration and imaging performance specifications. An optical designer will tell you that field curvature is one of the five monochromatic aberrations which they try to eliminate. The fact that one DOD development effort considers field curvature a design feature immediately draws attention to the project. This coupled with the paucity of published information and the very high development cost makes this program irresistible for comparison with competing approaches. This paper examines the likely design and performance of a proxy telescope intended to find NEOs, compares and contrasts that telescope with similar, but lower cost on-going projects, and examines the predictable impacts of reproducing such a telescope and placing multiple copies around the globe. The study primarily concentrates on performance measured in terms of search rate in square degrees per hour vs. object visual magnitude. Other considerations such as cost, transportability, availability of replacement components and ease of installation are also considered.

  18. LISA Telescope Spacer Design Issues

    NASA Technical Reports Server (NTRS)

    Livas, Jeff; Arsenovic, P.; Catelluci, K.; Generie, J.; Howard, J.; Stebbins, Howard R.; Preston, A.; Sanjuan, J.; Williams, L.; Mueller, G.

    2010-01-01

    The LISA mission observes gravitational waves by measuring the separations between freely floating proof masses located 5 million kilometers apart with an accuracy of - 10 picometers. The separations are measured interferometrically. The telescope is an afocal Cassegrain style design with a magnification of 80x. The entrance pupil has a 40 cm diameter and will either be centered on-axis or de-centered off-axis to avoid obscurations. Its two main purposes are to transform the small diameter beam used on the optical bench to a diffraction limited collimated beam to efficiently transfer the metrology laser between spacecraft, and to receive the incoming light from the far spacecraft. It transmits and receives simultaneously. The basic optical design and requirements are well understood for a conventional telescope design for imaging applications, but the LISA design is complicated by the additional requirement that the total optical path through the telescope must remain stable at the picometer level over the measurement band during the mission to meet the measurement accuracy. We describe the mechanical requirements for the telescope and the preliminary work that has been done to understand the materials and mechanical issues associated with the design of a passive metering structure to support the telescope and to maintain the spacing between the primary and secondary mirrors in the LISA on-orbit environment. This includes the requirements flowdown from the science goals, thermal modeling of the spacecraft and telescope to determine the expected temperature distribution, layout options for the telescope including an on- and off-axis design. Plans for fabrication and testing will be outlined.

  19. Preliminary LISA Telescope Spacer Design

    NASA Technical Reports Server (NTRS)

    Livas, J.; Arsenovic, P.; Catellucci, K.; Generie, J.; Howard, J.; Stebbins, R. T.

    2010-01-01

    The Laser Interferometric Space Antenna (LISA) mission observes gravitational waves by measuring the separations between freely floating proof masses located 5 million kilometers apart with an accuracy of approximately 10 picometers. The separations are measured interferometrically. The telescope is an afocal Cassegrain style design with a magnification of 80x. The entrance pupil has a 40 cm diameter and will either be centered on-axis or de-centered off-axis to avoid obscurations. Its two main purposes are to transform the small diameter beam used on the optical bench to a diffraction limited collimated beam to efficiently transfer the metrology laser between spacecraft, and to receive the incoming light from the far spacecraft. It transmits and receives simultaneously. The basic optical design and requirements are well understood for a conventional telescope design for imaging applications, but the LISA design is complicated by the additional requirement that the total optical path through the telescope must remain stable at the picometer level over the measurement band during the mission to meet the measurement accuracy. This poster describes the requirements for the telescope and the preliminary work that has been done to understand the materials and mechanical issues associated with the design of a passive metering structure to support the telescope and to maintain the spacing between the primary and secondary mirrors in the LISA on-orbit environment. This includes the requirements flowdown from the science goals, thermal modeling of the spacecraft and telescope to determine the expected temperature distribution,layout options for the telescope including an on- and off-axis design, and plans for fabrication and testing.

  20. A new ultra high energy gamma ray telescope at Ohya mine

    NASA Technical Reports Server (NTRS)

    Aoki, T.; Higashi, S.; Kamiya, Y.; Kitamura, T.; Matsuno, S.; Mizutani, K.; Mitsui, K.; Muraki, Y.; Okada, A.; Ohashi, Y.

    1985-01-01

    The search for ultra high energy gamma rays coming from point sources is one of the main experimental aims. A fast air shower timing system was constructed at ICRR for the study of the angular resolution of the system and operated approximately half a year. The characteristics of the surface array of Ohya air shower telescope is described.

  1. James Webb Space Telescope Optical Telescope Element Mirror Coatings

    NASA Technical Reports Server (NTRS)

    Keski-Kuha, Ritva A.; Bowers, Charles W.; Quijada, Manuel A.; Heaney, James B.; Gallagher, Benjamin; McKay, Andrew; Stevenson, Ian

    2012-01-01

    James Webb Space Telescope (JWST) Optical Telescope Element (OTE) mirror coating program has been completed. The science goals of the JWST mission require a uniform, low stress, durable optical coating with high reflectivity over the JWST spectral region. The coating has to be environmentally stable, radiation resistant and compatible with the cryogenic operating environment. The large size, 1.52 m point to point, light weight, beryllium primary mirror (PM) segments and flawless coating process during the flight mirror coating program that consisted coating of 21 flight mirrors were among many technical challenges. This paper provides an overview of the JWST telescope mirror coating program. The paper summarizes the coating development program and performance of the flight mirrors.

  2. Large aperture millimeter/submillimeter telescope: which is more cost-effective, aperture synthesis telescope versus large single dish telescope?

    NASA Astrophysics Data System (ADS)

    Iguchi, Satoru; Saito, Masao

    2016-07-01

    The Atacama Large Millimeter/submillimeter Array (ALMA) consists of 66 antennas with the aperture equivalent to a 91-m diameter antenna. The Green Bank Telescope (GBT) is the world's largest, 100-m diameter telescope in the wavelength range of 3 mm to 30 cm. The Large Millimeter Telescope (LMT) will be the world's largest, 50-m diameter, steerable millimeter-wavelength telescope. The Cerro Chajnantor Atacama Telescope (CCAT) will be the world's largest, 25-m diameter, submillimeter-wavelength telescope. We will investigate advantages and disadvantages of both the aperture synthesis telescope and the large single-dish telescope taking the cost effectiveness into consideration, and will propose the design of antenna structure for a future telescope project at millimeter and submillimeter wavelengths.

  3. The Spitzer Space Telescope Mission

    NASA Technical Reports Server (NTRS)

    Werner, M. W.

    2005-01-01

    The Spitzer Space Telescope, NASA's Great Observatory for infrared astronomy, was launched 2003 August 25 and is returning excellent scientific data from its Earth-trailing solar orbit. Spitzer combines the intrinsic sensitivity achievable with a cryogenic telescope in space with the great imaging and spectroscopic power of modern detector arrays to provide the user community with huge gains in capability for exploration of the cosmos in the infrared. The observatory systems are largely performing as expected, and the projected cryogenic lifetime is about five years. Spitzer is thus both a scientific and a technical precursor to the infrared astronomy missions of the future. This very brief paper refers interested readers to several sets of recent publications which describe both the scientific and the technical features of Spitzer in detail. Note that, until 2003 December, Spitzer was known as the Space Infrared Telescope Facility (SIRTF).

  4. Quantum telescope: feasibility and constraints.

    PubMed

    Kurek, A R; Pięta, T; Stebel, T; Pollo, A; Popowicz, A

    2016-03-15

    The quantum telescope is a recent idea aimed at beating the diffraction limit of spaceborne telescopes and possibly other distant target imaging systems. There is no agreement yet on the best setup of such devices, but some configurations have already been proposed. In this Letter we characterize the predicted performance of quantum telescopes and their possible limitations. Our extensive simulations confirm that the presented model of such instruments is feasible and the device can provide considerable gains in the angular resolution of imaging in the UV, optical, and infrared bands. We argue that it is generally possible to construct and manufacture such instruments using the latest or soon to be available technology. We refer to the latest literature to discuss the feasibility of the proposed QT system design.

  5. Double Compton scatter telescope calibration

    NASA Technical Reports Server (NTRS)

    Dayton, B.; Simone, J.; Green, M.; Long, J.; Zanrosso, E.; Zych, A. D.; White, R. S.

    1981-01-01

    Calibration techniques for a medium energy gamma ray telescope are described. Gain calibration using Compton edge spectra involves comparisons of pulse height spectra with spectra simulated by a Monte Carlo computer code which includes Compton scattering and pair production, plural scattering and variable energy resolution, and cell size. The telescope considered comprises 56 cells of liquid scintillator in four size groups, with a total liquid volume of 325 l; each cell has its own photomultiplier tube. Energy and angular resolutions and the PMT gain calibration procedure are verified with double scatter data for monoenergetic gamma rays at a known location. Detection probabilities for any cell combination in the two telescope arrays are calculated per steradian as a function of the scattering for a number of different energies with a Van de Graaff accelerator.

  6. Feature-based telescope scheduler

    NASA Astrophysics Data System (ADS)

    Naghib, Elahesadat; Vanderbei, Robert J.; Stubbs, Christopher

    2016-07-01

    Feature-based Scheduler offers a sequencing strategy for ground-based telescopes. This scheduler is designed in the framework of Markovian Decision Process (MDP), and consists of a sub-linear online controller, and an offline supervisory control-optimizer. Online control law is computed at the moment of decision for the next visit, and the supervisory optimizer trains the controller by simulation data. Choice of the Differential Evolution (DE) optimizer, and introducing a reduced state space of the telescope system, offer an efficient and parallelizable optimization algorithm. In this study, we applied the proposed scheduler to the problem of Large Synoptic Survey Telescope (LSST). Preliminary results for a simplified model of LSST is promising in terms of both optimality, and computational cost.

  7. LSST telescope and site status

    NASA Astrophysics Data System (ADS)

    Gressler, William J.

    2016-07-01

    The Large Synoptic Survey Telescope (LSST) Project1 received its construction authorization from the National Science Foundation in August 2014. The Telescope and Site (T and S) group has made considerable progress towards completion in subsystems required to support the scope of the LSST science mission. The LSST goal is to conduct a wide, fast, deep survey via a 3-mirror wide field of view optical design, a 3.2-Gpixel camera, and an automated data processing system. The summit facility is currently under construction on Cerro Pachón in Chile, with major vendor subsystem deliveries and integration planned over the next several years. This paper summarizes the status of the activities of the T and S group, tasked with design, analysis, and construction of the summit and base facilities and infrastructure necessary to control the survey, capture the light, and calibrate the data. All major telescope work package procurements have been awarded to vendors and are in varying stages of design and fabrication maturity and completion. The unique M1M3 primary/tertiary mirror polishing effort is completed and the mirror now resides in storage waiting future testing. Significant progress has been achieved on all the major telescope subsystems including the summit facility, telescope mount assembly, dome, hexapod and rotator systems, coating plant, base facility, and the calibration telescope. In parallel, in-house efforts including the software needed to control the observatory such as the scheduler and the active optics control, have also seen substantial advancement. The progress and status of these subsystems and future LSST plans during this construction phase are presented.

  8. EST: The European Solar Telescope

    NASA Astrophysics Data System (ADS)

    Collados, M.

    2008-09-01

    The European Solar Telescope (EST) is a project for a 4 meter-class ground-based telescope, to be located in the Canary Islands. The project is promoted by the European Association for Solar Telescopes (EAST), a consortium formed by research organizations from 15 European countries. EST will be optimized for studies of magnetic coupling between the deep photosphere and upper chromosphere. The project has been approved for funds by the European Union, within the FP-7 framework, to produce the design of all systems and subsystems of the telescope during the next three years. This includes the optical and optomechanical design of the telescope itself and of the instruments and their control. MCAO will be included in the optical path in a natural way to compensate for atmospheric disturbances in an optimum way. The design of EST will strongly emphasize the use of a large number of visible and near-infrared instruments simultaneously which will influence the telescope design from the very beginning. This communication will center mainly on the scientific objectives that EST will address. Generally speaking, they involve understanding how the magnetic field emerges through the solar surface, interacts with the plasma dynamics to transfer energy between different regions, and finally releases it in the form of heat or as violent events in the solar chromosphere and corona. Among the many topics of interest, one may cite, as described in the EST Science Requirements Document: small-scale flux emergence in quiet sun regions, large-scale magnetic structures, magnetic flux cancellation processes, polar magnetic fields, magnetic topology of the photosphere and chromosphere, conversion of mechanical to magnetic energy in the photosphere, wave propagation from photosphere to chromosphere, energy dissipation in the chromosphere at small and large scales, etc. The present status and future perspectives of the project will also be outlined.

  9. The James Webb Space Telescope

    NASA Technical Reports Server (NTRS)

    Greenhouse, Matthew

    2008-01-01

    The James Webb Space Telescope is being developed by NASA in partnership with the European and Canadian space agencies for launch during 2013. This mission is expected to carry the legacy of discovery of the Hubble Space Telescope through the next decade, and is designed with unique capability to address key questions about formation of the first galaxies after the Big Bang, their subsequelet volution, and the formation of stars and planets within our own galaxy. This talk will present an overview of the mission science objectives and the status of the mission development.

  10. Superconductor lunar telescopes --Abstract only

    NASA Technical Reports Server (NTRS)

    Chen, P. C.; Pitts, R.; Shore, S.; Oliversen, R.; Stolarik, J.; Segal, K.; Hojaji, H.

    1994-01-01

    We propose a new type of telescope designed specifically for the lunar environment of high vacuum and low temperature. Large area UV-Visible-IR telescope arrays can be built with ultra-light-weight replica optics. High T(sub c) superconductors provide support, steering, and positioning. Advantages of this approach are light-weight payload compatible with existing launch vehicles, configurable large area optical arrays, no excavation or heavy construction, and frictionless electronically controlled mechanisms. We have built a prototype and will be demonstarting some of its working characteristics.

  11. Apollo Telescope Mount Spar Assembly

    NASA Technical Reports Server (NTRS)

    1969-01-01

    The Apollo Telescope Mount (ATM), designed and developed by the Marshall Space Flight Center, served as the primary scientific instrument unit aboard the Skylab. The ATM contained eight complex astronomical instruments designed to observe the Sun over a wide spectrum from visible light to x-rays. This image shows the ATM spar assembly. All solar telescopes, the fine Sun sensors, and some auxiliary systems are mounted on the spar, a cruciform lightweight perforated metal mounting panel that divides the 10-foot long canister lengthwise into four equal compartments. The spar assembly was nested inside a cylindrical canister that fit into the rack, a complex frame, and was protected by the solar shield.

  12. Wide field of view telescope

    DOEpatents

    Ackermann, Mark R.; McGraw, John T.; Zimmer, Peter C.

    2008-01-15

    A wide field of view telescope having two concave and two convex reflective surfaces, each with an aspheric surface contour, has a flat focal plane array. Each of the primary, secondary, tertiary, and quaternary reflective surfaces are rotationally symmetric about the optical axis. The combination of the reflective surfaces results in a wide field of view in the range of approximately 3.8.degree. to approximately 6.5.degree.. The length of the telescope along the optical axis is approximately equal to or less than the diameter of the largest of the reflective surfaces.

  13. The network of INTA telescopes

    NASA Astrophysics Data System (ADS)

    Cuesta, L.

    2008-06-01

    The Spanish Instituto Nacional de Técnica Aeroespacial has a network of three telescopes located at some of the best places for astronomy in mainland Spain. The first is at the Observatorio de Calar Alto in Almeria, at an altitude of more than 2100 m. The second is near Calatayud in Zaragoza, at the summit of a 1400-m high mountain. The last is on the campus of the Instituto Nacional de Técnica Aerospatial (INTA), in Madrid. The three telescopes are either 40 or 50 cm in diameter and will be available for communications and educational projects.

  14. Artificial Intelligence in Autonomous Telescopes

    NASA Astrophysics Data System (ADS)

    Mahoney, William; Thanjavur, Karun

    2011-03-01

    Artificial Intelligence (AI) is key to the natural evolution of today's automated telescopes to fully autonomous systems. Based on its rapid development over the past five decades, AI offers numerous, well-tested techniques for knowledge based decision making essential for real-time telescope monitoring and control, with minimal - and eventually no - human intervention. We present three applications of AI developed at CFHT for monitoring instantaneous sky conditions, assessing quality of imaging data, and a prototype for scheduling observations in real-time. Closely complementing the current remote operations at CFHT, we foresee further development of these methods and full integration in the near future.

  15. LISA telescope spacer design investigations

    NASA Astrophysics Data System (ADS)

    Sanjuan, Josep; Mueller, Guido; Livas, Jeffrey; Preston, Alix; Arsenovic, Petar; Castellucci, Kevin; Generie, Joseph; Howard, Joseph; Stebbins, Robin

    The Laser Interferometer Space Antenna (LISA) is a space-based gravitational wave observa-tory with the goal of observing Gravitational Waves (GWs) from astronomical sources in a frequency range from 30 µHz to 0.1 Hz. The detection of GWs at such low frequency requires measurements of distances at the pico-meter level between bodies separated by 5 million kilo-meters. The LISA mission consists of three identical spacecraft (SC) separated by 5 × 106 km forming an equilateral triangle. Each SC contains two optical assemblies and two vacuum en-closures housing one proof mass (PM) in geodesic (free fall) motion each. The two assemblies on one SC are each pointing towards an identical assembly on each of the other two SC to form a non-equal arm interferometer. The measurement of the GW strain is done by measuring the change in the length of the optical path between the PMs of one arm relative to the other arms caused by the pass of a GW. An important element of the Interferometric Measurement System (IMS) is the telescope which, on one hand, gathers the light coming from the far SC (˜100 pW) and, on the other hand, expands and collimates the small outgoing beam ( 1 W) and sends it to the far SC. Due to the very demanding sensitivity requirements care must be taken in the design and validation of the telescope not to degrade the IMS performance. For instance, the diameter of the telescope sets the the shot noise of the IMS and depends critically on the diameter of the primary and the divergence angle of the outgoing beam. As the telescope is rather fast telescope, the divergence angle is a critical function of the overall separation between the primary and secondary. Any long term changes of the distance of more than a a few micro-meter would be detrimental to the LISA mission. Similarly challenging are the requirements on the in-band path-length noise for the telescope which has to be kept below 1 pm Hz-1/2 in the LISA band. Different configurations (on-axis/off axis

  16. New Information about Old Telescopes

    NASA Astrophysics Data System (ADS)

    Van Helden, Albert

    2016-01-01

    It has long been known that the earliest telescopes were primitive, suffering from a number of defects such as spherical and chromatic aberrations, grinding and polishing errors, and poor quality glass. In the last two decades, much new information has been uncovered by the cooperation between historians and scientists. As a result, we now have a much better, and more complete, history of early telescopes, from spectacle lenses and the invention of the instrument to the demise of long-focus non-achromatic refractors and their replacement by reflectors in the eighteenth century. We can begin to quantify the properties of these early instruments, and the results are often surprising.

  17. Cherenkov telescopes as optical telescopes for bright sources: today's specialized 30-m telescopes?

    NASA Astrophysics Data System (ADS)

    Lacki, Brian C.

    2011-10-01

    Imaging Atmospheric Cherenkov Telescopes (IACTs) use large-aperture (3-30 m) optical telescopes with arcminute angular resolution to detect TeV gamma-rays in the atmosphere. I show that IACTs are well suited for optical observations of bright sources (V≲ 8-10), because these sources are brighter than the sky background. Their advantages are especially great on rapid time-scales. Thus, IACTs might study many phenomena optically, including transiting exoplanets and the brightest gamma-ray bursts. In principle, an IACT could achieve millimagnitude photometry of these objects with second-long exposures. I also consider the potential for optical spectroscopy with IACTs, finding that their poor angular resolution limits their usefulness for high spectral resolutions, unless complex instruments are developed. The high photon collection rate of IACTs is potentially useful for precise polarimetry. Finally, I briefly discuss the broader possibilities of extremely large, low-resolution telescopes, including a 10 arcsec resolution telescope and space-borne telescopes.

  18. The MIDAS telescope for microwave detection of ultra-high energy cosmic rays

    NASA Astrophysics Data System (ADS)

    Alvarez-Muñiz, J.; Amaral Soares, E.; Berlin, A.; Bogdan, M.; Boháčová, M.; Bonifazi, C.; Carvalho, W. R.; de Mello Neto, J. R. T.; Facal San Luis, P.; Genat, J. F.; Hollon, N.; Mills, E.; Monasor, M.; Privitera, P.; Ramos de Castro, A.; Reyes, L. C.; Richardson, M.; Rouille d'Orfeuil, B.; Santos, E. M.; Wayne, S.; Williams, C.; Zas, E.; Zhou, J.

    2013-08-01

    We present the design, implementation and data taking performance of the MIcrowave Detection of Air Showers (MIDAS) experiment, a large field of view imaging telescope designed to detect microwave radiation from extensive air showers induced by ultra-high energy cosmic rays. This novel technique may bring a tenfold increase in detector duty cycle when compared to the standard fluorescence technique based on detection of ultraviolet photons. The MIDAS telescope consists of a 4.5 m diameter dish with a 53-pixel receiver camera, instrumented with feed horns operating in the commercial extended C-Band (3.4-4.2 GHz). A self-trigger capability is implemented in the digital electronics. The main objectives of this first prototype of the MIDAS telescope - to validate the telescope design, and to demonstrate a large detector duty cycle - were successfully accomplished in a dedicated data taking run at the University of Chicago campus prior to installation at the Pierre Auger Observatory.

  19. LSST Telescope and Site Overview

    NASA Astrophysics Data System (ADS)

    Krabbendam, Victor; Claver, C. F.; Andrew, J.; Barr, J.; Gressler, W.; Kingsley, J.; Neill, D. R.; Olivier, S.; Sebag, J.; LSST Collaboration

    2007-12-01

    The LSST Telescope and Site has been designed to meet the stringent goals of the survey in terms of image quality and throughput. The telescope system delivers 0.25 arc sec FWHM seeing to the overall system image quality error budget. An active optics control system has been identified to measure wavefront quality in the focal plane and use this to reconstruct the figure and alignment errors in the optics. The primary-tertiary monolithic mirror is being fabricated at the Steward Observatory Mirror Lab using their structured borosilicate spin casting technology. Fabrication of the mold is underway, with "high fire” scheduled for spring 2008, and final delivery in late 2011. Baseline designs for active mirror support and optical testing for the monolith and conventional secondary mirror systems have been developed. The telescope is compact, stiff, and agile to maximize observing efficiency. The 300 ton structure can make 3.5 degree moves (at a 30 degree zenith angle) on the sky in less than 5 seconds. The dome will track and slew to follow the telescope pointing with minimal power. The summit facility has been designed to support operations and maintenance for minimal down time

  20. Neutrino telescopes in the World

    SciTech Connect

    Ernenwein, J.-P.

    2007-01-12

    Neutrino astronomy has rapidly developed these last years, being the only way to get specific and reliable information about astrophysical objects still poorly understood.Currently two neutrino telescopes are operational in the World: BAIKAL, in the lake of the same name in Siberia, and AMANDA, in the ices of the South Pole. Two telescopes of the same type are under construction in the Mediterranean Sea: ANTARES and NESTOR. All these telescopes belong to a first generation, with an instrumented volume smaller or equal to 0.02 km3. Also in the Mediterranean Sea, the NEMO project is just in its stag phase, within the framework of a cubic kilometer size neutrino telescope study. Lastly, the ICECUBE detector, with a volume reaching about 1 km3, is under construction on the site of AMANDA experiment, while an extension of the BAIKAL detector toward km3 is under study. We will present here the characteristics of these experiments, as well as the results of their observations.

  1. Hubble Space Telescope prescription retrieval.

    PubMed

    Redding, D; Dumont, P; Yu, J

    1993-04-01

    Prescription retrieval is a technique for directly estimating optical prescription parameters from images. We apply it to estimate the value of the Hubble Space Telescope primary mirror conic constant. Our results agree with other studies that examined primary-mirror test fixtures and results. In addition they show that small aberrations exist on the planetary-camera repeater optics.

  2. Fermi's Large Area Telescope (LAT)

    NASA Video Gallery

    Fermi’s Large Area Telescope (LAT) is the spacecraft’s main scientificinstrument. This animation shows a gamma ray (purple) entering the LAT,where it is converted into an electron (red) and a...

  3. Push-To Telescope Mathematics

    ERIC Educational Resources Information Center

    Teets, Donald

    2012-01-01

    Two coordinate systems are related here, one defined by the earth's equator and north pole, the other by the orientation of a telescope at some location on the surface of the earth. Applying an interesting though somewhat obscure property of orthogonal matrices and using the cross-product simplifies this relationship, revealing that a surprisingly…

  4. POST: a polar stratospheric telescope

    NASA Astrophysics Data System (ADS)

    Ford, Holland C.; Bely, Pierre Y.; Bally, John; Crocker, James H.; Dopita, Mike; Tilley, James N.; Allen, Ronald; Bartko, Frank; White, Richard L.; Burg, Richard; Burrows, Christopher J.; Clampin, Mark; Harper, Doyal A.; Illingworth, Garth; McCray, Richard; Meyer, Stephan; Mould, Jeremy; Norman, Colin

    1994-06-01

    The lower stratosphere in the polar regions offers conditions for observation in the near-infrared comparable to those obtained from space. We describe a concept for a 6-meter, diluted aperture, near-infrared telescope carried by a tethered aerostat flying at 12 km altitude, to serve as a testbed for future space astronomical observatories while producing frontier science.

  5. GISOT: a giant solar telescope

    NASA Astrophysics Data System (ADS)

    Hammerschlag, Robert H.; von der Lühe, Oskar F.; Bettonvil, Felix C.; Jägers, Aswin P.; Snik, Frans

    2004-10-01

    A concept is presented for an extremely large high-resolution solar telescope with an aperture of 11 m and diffraction limited for visual wavelengths. The structure of GISOT will be transparent to wind and placed on a transparent stiff tower. For efficient wind flushing, all optics, including the primary mirror, will be located above the elevation axis. The aperture will be of the order of 11 m, not rotatively symmetrical, but of an elongated shape with dimensions 11 x 4 m. It consists of a central on-axis 4 m mirror with on both sides 3 pieces of 2 m mirrors. The optical layout will be kept simple to guarantee quality and minimize stray light. A Coudé room for instruments is planned below the telescope. The telescope will not be housed in a dome-like construction, which interferes with the open principle. Instead the telescope will be protected by a foldable tent construction with a diameter of the order of 30 m, which doesn"t form any obstruction during observations, but can withstand the severe weather circumstances on mountain sites. Because of the nature of the solar scene, extremely high resolution in only one dimension is sufficient to solve many exciting problems in solar physics and in this respect the concept of GISOT is very promising.

  6. The New Robotic Telescope at Oklahoma State University

    NASA Astrophysics Data System (ADS)

    Shull, Peter, Jr.

    2007-12-01

    A new, 0.6-m robotic telescope of Ritchey-Chrétien design was recently installed at the H. S. Mendenhall Observatory (HSMO) of Oklahoma State University (OSU), and is now undergoing operational tests. Funded by the Air Force Office of Scientific Research through the Defense University Research Instrumentation Program, it replaces HSMO's original 0.35-m Schmidt-Cassegrain telescope. Research programs will include the characterization of near-Earth objects and collaborative searches for transiting exoplanets, programs which will also open up new research opportunities for students in the Oklahoma-Arkansas region. Ideally, these opportunities will attract more undergraduate and graduate students to major in physics and astronomy, and foster the creation of degree programs in astronomy at OSU. Optical Guidance Systems was the contractor for both the telescope and dome automation. The telescope's ceramic 602-mm f/3 primary and 220-mm secondary mirrors yield an effective focal ratio of f/8 that can be changed to f/5.3 with a focal reducer / field flattener. Fields of view range from 0.75° at f/5.3 to 1.2° at f/8. The Strehl ratio is 0.954. The telescope's carbon-fiber Serrurier truss is supported by an equatorial fork mount equipped with friction drives. Telescope equipment includes a 35-mm-format CCD camera with UBVRI filters, field rotator, off-axis guider, and flip-mirror unit for quick switches to eyepiece observing. HSMO itself is conveniently located under reasonably dark skies at an elevation of 340 m about 15 km southwest of the city of Stillwater, whose population, including OSU, is approaching 50,000. HSMO's dome was completed in 2002, and funding is being raised for a control building near the dome. The observatory's URL is www.physics.okstate.edu/observatory.

  7. Laser Truss Sensor for Segmented Telescope Phasing

    NASA Technical Reports Server (NTRS)

    Liu, Duncan T.; Lay, Oliver P.; Azizi, Alireza; Erlig, Herman; Dorsky, Leonard I.; Asbury, Cheryl G.; Zhao, Feng

    2011-01-01

    A paper describes the laser truss sensor (LTS) for detecting piston motion between two adjacent telescope segment edges. LTS is formed by two point-to-point laser metrology gauges in a crossed geometry. A high-resolution (<30 nm) LTS can be implemented with existing laser metrology gauges. The distance change between the reference plane and the target plane is measured as a function of the phase change between the reference and target beams. To ease the bandwidth requirements for phase detection electronics (or phase meter), homodyne or heterodyne detection techniques have been used. The phase of the target beam also changes with the refractive index of air, which changes with the air pressure, temperature, and humidity. This error can be minimized by enclosing the metrology beams in baffles. For longer-term (weeks) tracking at the micron level accuracy, the same gauge can be operated in the absolute metrology mode with an accuracy of microns; to implement absolute metrology, two laser frequencies will be used on the same gauge. Absolute metrology using heterodyne laser gauges is a demonstrated technology. Complexity of laser source fiber distribution can be optimized using the range-gated metrology (RGM) approach.

  8. A Cerenkov-delta E-Cerenkov detector for high energy cosmic ray isotopes and an accelerator study of Ar-40 and Fe-56 fragmentation. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Lau, K. H.

    1985-01-01

    A high energy cosmic ray detector--the High Energy Isotope Spectrometer Telescope (HEIST) is described. It is a large area (0.25 m(swp 2) SR) balloon borne isotope spectrometer designed to make high resolution measurements of isotopes in the element range from neon to nickel (10 Z 28) at energies of about 2 GeV/nucleon. HEIST determines the mass of individual nuclei by measuring both the change in the Lorentz factor (delta gamma) that results from traversing the NaI stack, and the energy loss (delta E) in the stack. Since the total energy of an isotope is given by E = (gamma M), the mass M can be determined by M = delta E/delta, gamma. The instrument is designed to achieve a typical mass resolution of 0.2 amu. The isotopic composition of the fragments from the breakup of high energy An-40 and Fe-56 nuclei are measured experimentally. Isotope yields are compared with calculated yields based on semi-empirical cross-section formulae.

  9. FORCAST Camera Installed on SOFIA Telescope

    NASA Video Gallery

    Cornell University's Faint Object Infrared Camera for the SOFIA Telescope, or FORCAST, being installed on the Stratospheric Observatory for Infrared Astronomy's 2.5-meter telescope in preparation f...

  10. Rangefinder Metrology for the Green Bank Telescope

    NASA Astrophysics Data System (ADS)

    Goldman, M. A.; Creager, R. E.; Parker, D. H.; Payne, J. A.

    A scanning laser rangefinder metrology system for the 100 meter Green Bank Telescope is described. Use of this system for correction of the primary reflector's shape and pointing of the telescope is described.

  11. Eclipse Photographs Through a Small Telescope

    NASA Astrophysics Data System (ADS)

    Kramer, Bill

    1999-08-01

    Results of previous eclipse photography using a small telescope (Questar 90mm x 1200mm EFL) and camera. During the presentation of images, tips and ideas for getting good pictures through a telescope will be discussed.

  12. Galileo, telescopic astronomy, and the Copernican system.

    NASA Astrophysics Data System (ADS)

    van Helden, A.

    Contents: 1. Introduction. 2. Telescopic discoveries. 3. Sunspots, Copernicanism, and theology. 4. The decree of 1616. 5. The Dialogue. 6. The trial of Galileo. 7. The aftermath of the trial. 8. Telescopic astronomy after Galileo.

  13. Novel Usage for a Cosmic Ray Detector: Study of Lightning at Telescope Array

    NASA Astrophysics Data System (ADS)

    Belz, John; Okuda, Takeshi

    We describe observations performed at the Telescope Array Observatory in which "bursts" of air shower triggers of the surface detector occur in close temporal and spatial coincidence with lighting. These events appear to be consistent with other observations of high-energy particle showers produced by lightning. Telescope Array has the ability to reconstruct these showers using modified UHECR air shower reconstruction techniques, and thus determine the source of particles in the atmospheric breakdown. We describe new efforts to deploy lightning mapping detectors at the Telescope Array site which will enable further study of this phenomenon, along with enabling us to search for evidence of lightning strikes being "seeded" under certain atmospheric conditions by the passage of a UHECR air shower.

  14. Origins Space Telescope: Telescope Design and Instrument Specifications

    NASA Astrophysics Data System (ADS)

    Meixner, Margaret; Carter, Ruth; Leisawitz, David; Dipirro, Mike; Flores, Anel; Staguhn, Johannes; Kellog, James; Roellig, Thomas L.; Melnick, Gary J.; Bradford, Charles; Wright, Edward L.; Zmuidzinas, Jonas; Origins Space Telescope Study Team

    2017-01-01

    The Origins Space Telescope (OST) is the mission concept for the Far-Infrared Surveyor, one of the four science and technology definition studies of NASA Headquarters for the 2020 Astronomy and Astrophysics Decadal survey. The renaming of the mission reflects Origins science goals that will discover and characterize the most distant galaxies, nearby galaxies and the Milky Way, exoplanets, and the outer reaches of our Solar system. This poster will show the preliminary telescope design that will be a large aperture (>8 m in diameter), cryogenically cooled telescope. We will also present the specifications for the spectrographs and imagers over a potential wavelength range of ~10 microns to 1 millimeter. We look forward to community input into this mission definition over the coming year as we work on the concept design for the mission. Origins will enable flagship-quality general observing programs led by the astronomical community in the 2030s. We welcome you to contact the Science and Technology Definition Team (STDT) with your science needs and ideas by emailing us at firsurveyor_info@lists.ipac.caltech.edu.

  15. A 2.5m astronomical telescope project

    NASA Astrophysics Data System (ADS)

    Phaichith, Oudomsanith

    2008-07-01

    The paper reports a recently started project for a 2,5 meter diameter robotic telescope dedicated to astronomy and education for the University of Moscow's Sternberg Institute. As a prime contractor Sagem Defense Securite's REOSC department will take on the program design as well as the production of the optical components. The project includes the Alt-Az mount, the dome and its cooling and air stabilization system, the weather station, the high-resolution camera and realization, transport and installation on-site at the Kislovodsk solar station located in the Caucasus mountains as well as the initial training for the operators. The telescope will provide a wide field of view of 40 arcmin at the Cassegrain F/8 focus. An escapable and rotating tertiary mirror will allow to direct the light to the two Nasmyth foci and two student ports located at 90° from the Nasmyth foci. A 4k x 4k CCD camera cryogenically cooled to 140 K will be provided as a first light camera. All will be delivered by end 2009. Remotely controlled via the internet, the telescope will allow Russia to train doctors in astronomy, participate in international research projects and draw up the future specifications of a larger and more advanced telescope.

  16. The Next Generation Space Telescope

    NASA Technical Reports Server (NTRS)

    Bely, Pierre-Yves (Editor); Burrows,, Christopher J. (Editor); Illingworth,, Garth D.

    1989-01-01

    In Space Science in the Twenty-First Century, the Space Science Board of the National Research Council identified high-resolution-interferometry and high-throughput instruments as the imperative new initiatives for NASA in astronomy for the two decades spanning 1995 to 2015. In the optical range, the study recommended an 8 to 16-meter space telescope, destined to be the successor of the Hubble Space Telescope (HST), and to complement the ground-based 8 to 10-meter-class telescopes presently under construction. It might seem too early to start planning for a successor to HST. In fact, we are late. The lead time for such major missions is typically 25 years, and HST has been in the making even longer with its inception dating back to the early 1960s. The maturity of space technology and a more substantial technological base may lead to a shorter time scale for the development of the Next Generation Space Telescope (NGST). Optimistically, one could therefore anticipate that NGST be flown as early as 2010. On the other hand, the planned lifetime of HST is 15 years. So, even under the best circumstances, there will be a five year gap between the end of HST and the start of NGST. The purpose of this first workshop dedicated to NGST was to survey its scientific potential and technical challenges. The three-day meeting brought together 130 astronomers and engineers from government, industry and universities. Participants explored the technologies needed for building and operating the observatory, reviewed the current status and future prospects for astronomical instrumentation, and discussed the launch and space support capabilities likely to be available in the next decade. To focus discussion, the invited speakers were asked to base their presentations on two nominal concepts, a 10-meter telescope in space in high earth orbit, and a 16-meter telescope on the moon. The workshop closed with a panel discussion focused mainly on the scientific case, siting, and the

  17. The Hubble Space Telescope: Problems and Solutions.

    ERIC Educational Resources Information Center

    Villard, Ray

    1990-01-01

    Presented is the best understanding of the flaw discovered in the optics of the Hubble Space Telescope and the possible solutions to the problems. The spherical aberration in the telescope's mirror and its effect on the quality of the telescope's imaging ability is discussed. (CW)

  18. World atlas of large optical telescopes

    NASA Technical Reports Server (NTRS)

    Meszaros, S. P.

    1979-01-01

    By 1980 there will be approximately 100 large optical telescopes in the world with mirror or lens diameters of one meter (39 inches) and larger. This atlas gives information on these telescopes and shows their locations on continent-sized maps. Observatory locations considered suitable for the construction of future large telescopes are also shown.

  19. 2m class telescope project at Lijiang

    NASA Astrophysics Data System (ADS)

    Chen, Dong; Wang, Jian-Cheng; Xu, Jun; Zhang, Bai-Rong; Luo, Guo-Quan; Liu, Zhong; Tan, Hui-Song

    Supported by the ministry of science and technology, government of Yunnan Province and Chinese Academy of Sciences, a 2m class telescope project was granted. In this paper, we will first review the site, Gaomeigu, briefly, then give the details of 2m class telescope project, and finally discuss the future plans of this new telescope.

  20. The Baker Observatory Robotic Autonomous Telescope

    NASA Astrophysics Data System (ADS)

    Hicks, L. L.; Reed, M. D.; Thompson, M. A.; Gilker, J. T.

    We describe the Baker Observatory Robotic Autonomous Telescope project. The hardware includes a 16 inch Meade LX-200 telescope, an AstroHaven 7 feet dome, an Apogee U47 CCD camera and filter wheel, a Boltwood Cloud Sensor II, and various other minor hardware. We are implementing RTS2 for the Telescope Control System and incorporating custom drivers for ancillary systems.

  1. The National Large Solar Telescope (NLST) of India

    NASA Astrophysics Data System (ADS)

    Hasan, S. S.

    2012-12-01

    The Indian National Large Solar Telescope (NLST) will be a state-of-the-art 2-m class telescope for carrying out high-resolution studies in the solar atmosphere. Recent numerical simulations suggest that crucial physical processes like vortex flow, dissipation of magnetic fields and the generation of MHD waves can occur efficiently over length scales of tens of kilometers. Current telescopes are unable to resolve solar feature to this level at visible wavelengths. NLST will not only achieve good spatial resolution, but will also have a high photon throughput in order to carry out spectropolarimetric observations to accurately measure vector magnetic fields in the solar atmosphere with a good signal to noise ratio. The main science goals of NLST include: a) Magnetic field generation and the solar cycle; b) Dynamics of magnetized regions; c) Helioseismology; d) Long term variability; e) Energetic phenomena and Activity; and f) Night time astronomy. The optical design of the telescope is optimized for high optical throughput and uses a minimum number of optical elements. A high order adaptive optics system is integrated as part of the design that works with a modest Fried's parameter of 7-cm to give diffraction limited performance. The telescope will be equipped with a suite of post-focus instruments including a high resolution spectrograph and a polarimeter. NLST will also be used for carrying out stellar observations during the night. The mechanical design of the telescope, building, and the innovative dome takes advantage of the natural air flush which will help to keep the open telescope in temperature equilibrium. Critical to the successful implementation of NLST is the selection of a site with optimum atmospheric properties, such as the number of sunshine hours and good "seeing" over long periods. A site characterization programme carried over several years has established the existence of suitable sites in the Ladakh region. After its completion, currently

  2. Spitzer Space Telescope mission design

    NASA Technical Reports Server (NTRS)

    Kwok, Johnny H.; Garcia, Mark D.; Bonfiglio, Eugene; Long, Stacia M.

    2004-01-01

    This paper gives a description of the mission design, launch, orbit, and navigation results for the Spitzer space telescope mission. The Spitzer telescope was launched by the Delta II Heavy launch vehicle into a heliocentric Earth trailing orbit. This orbit is flown for the first time and will be used by several future astronomical missions such as Kepler, SIM, and LISA. This paper describes the launch strategy for a winter versus a summer launch and how it affects communications. It also describes how the solar orbit affects the design and operations of the Observatory. It describes the actual launch timeline, launch vehicle flight performance, and the long term behavior of the as flown orbit. It also provides the orbit knowledge from in-flight navigation data.

  3. Focusing X-Ray Telescopes

    NASA Technical Reports Server (NTRS)

    O'Dell, Stephen; Brissenden, Roger; Davis, William; Elsner, Ronald; Elvis, Martin; Freeman, Mark; Gaetz, Terrance; Gorenstein, Paul; Gubarev, Mikhall; Jerlus, Diab; Juda, Michael; Kolodziejczak, Jeffrey; Murray, Stephen; Petre, Robert; Podgorski, William; Ramsey, Brian; Reid, Paul; Saha, Timo; Wolk, Scott; Troller-McKinstry, Susan; Weisskopf, Martin; Wilke, Rudeger; Zhang, William

    2010-01-01

    During the half-century history of x-ray astronomy, focusing x-ray telescopes, through increased effective area and finer angular resolution, have improved sensitivity by 8 orders of magnitude. Here, we review previous and current x-ray-telescope missions. Next, we describe the planned next-generation x-ray-astronomy facility, the International X-ray Observatory (IXO). We conclude with an overview of a concept for the next next-generation facility, Generation X. Its scientific objectives will require very large areas (about 10,000 sq m) of highly-nested, lightweight grazing-incidence mirrors, with exceptional (about 0.1-arcsec) resolution. Achieving this angular resolution with lightweight mirrors will likely require on-orbit adjustment of alignment and figure.

  4. Kunlun Dark Universe Survey Telescope

    NASA Astrophysics Data System (ADS)

    Zhu, Yongtian; Wang, Lifan; Yuan, Xiangyan; Gu, Bozhong; Li, Xinnan; Yang, Shihai; Gong, Xuefei; Du, Fujia; Qi, Yongjun; Xu, Lingzhe

    2014-07-01

    Chinese Antarctic Observatory has been listed as National large research infrastructure during twelfth five-year plan. Kunlun Dark Universe Survey Telescope, one of two major facility of Chinese Antarctic Observatory, is a 2.5-meter optic/infrared telescope and will be built at the Chinese Antarctic Kunlun Station. It is intended to take advantage of the exceptional seeing conditions, as well as the low temperature reducing background for infrared observations. KDUST will adopt an innovative optical system, which can deliver very good image quality over a 2 square degree flat field of view. All of parts of it have been designed carefully to endure the extremely harsh environment. KDUST will be perched on a 14.5-meter-high tower to lift it above the turbulence layer. In this paper, preliminary design and key technology pre-research of KDUST will be introduced.

  5. Hubble Space Telescope Servicing begins.

    NASA Astrophysics Data System (ADS)

    1993-12-01

    The day's work began when astronauts Story Musgrave and Jeff Hoffman stepped out into the cargo bay at 9h41 pm CST, Saturday (4h41 am CET, Sunday). They immediately set to work replacing two gyroscope assemblies, known as the Rate Sensor Units, two associated electronics boxes, called Electronic Control Units, and eight electrical fuse plugs. The work was completed ahead of schedule, but the astronauts had trouble closing the doors of the compartment housing the gyros and took over an hour to get them shut. The astronauts also prepared equipment for the replacement of the solar arrays. "The feeling down here is one of great satisfaction for a tremendous job today" said spacecraft communicator Greg Harbaugh in mission control. "We are very proud of the work that you all did and we are very confident in the continued success of the mission. Everything is going great and tomorrow is going to be another great day". ESA astronaut Claude Nicollier played a vital role during the spacewalk moving the astronauts and their equipment around the cargo bay with the shuttle's robot arm. The Hubble Space Telescope servicing mission features more robot arm operations than any other shuttle flight. The telescope's left-hand solar array was rolled up successfully at 6h24 am CST (1h24 pm CET). The 11-tonne observatory was rotated 180 degrees on its turntable before commands were sent to retract the second array at 8h23 am CST (3h23 pm CET). The crew stopped the retraction when it appeared the system may have jammed. Mission control instructed the crew to jettison the array, a procedure that they have trained for. Tomorrow astronauts Kathy Thornton and Tom Akers will make a six-hour spacewalk to jettison the troublesome wing, store the other in the cargo bay, and install two new panels supplied by ESA. The second set of arrays feature thermal shields and a modified thermal compensation system to prevent the flexing that affected the first pair. The Hubble Space Telescope was plucked

  6. THE OPTIMAL GRAVITATIONAL LENS TELESCOPE

    SciTech Connect

    Surdej, J.; Hanot, C.; Sadibekova, T.; Delacroix, C.; Habraken, S.; Coleman, P.; Dominik, M.; Le Coroller, H.; Mawet, D.; Quintana, H.; Sluse, D.

    2010-05-15

    Given an observed gravitational lens mirage produced by a foreground deflector (cf. galaxy, quasar, cluster, ...), it is possible via numerical lens inversion to retrieve the real source image, taking full advantage of the magnifying power of the cosmic lens. This has been achieved in the past for several remarkable gravitational lens systems. Instead, we propose here to invert an observed multiply imaged source directly at the telescope using an ad hoc optical instrument which is described in the present paper. Compared to the previous method, this should allow one to detect fainter source features as well as to use such an optimal gravitational lens telescope to explore even fainter objects located behind and near the lens. Laboratory and numerical experiments illustrate this new approach.

  7. Telescoping Space-Station Modules

    NASA Technical Reports Server (NTRS)

    Witcofski, R. D.

    1986-01-01

    New telescoping-space-station design involves module within a module. After being carried to orbit within payload bay of Space Shuttle orbiter, outer module telescopically deployed to achieve nearly twice as much usable space-station volume per Space Shuttle launch. Closed-loop or "race-track" space-station configurations possible with this concept and provide additional benefits. One benefit involves making one of modules double-walled haven safe from debris, radiation, and like. Module accessible from either end, and readily available to all positions in space station. Concept also provides flexibility in methods in which Space Shuttle orbiter docked or berthed with space station and decrease chances of damage.

  8. The Ortega Telescope Andor CCD

    NASA Astrophysics Data System (ADS)

    Tucker, M.; Batcheldor, D.

    2012-07-01

    We present a preliminary instrument report for an Andor iKon-L 936 charge-couple device (CCD) being operated at Florida Tech's 0.8 m Ortega Telescope. This camera will replace the current Finger Lakes Instrumentation (FLI) Proline CCD. Details of the custom mount produced for this camera are presented, as is a quantitative and qualitative comparison of the new and old cameras. We find that the Andor camera has 50 times less noise than the FLI, has no significant dark current over 30 seconds, and has a smooth, regular flat field. The Andor camera will provide significantly better sensitivity for direct imaging programs and, once it can be satisfactorily tested on-sky, will become the standard imaging device on the Ortega Telescope.

  9. Workshop on Mars Telescopic Observations

    NASA Technical Reports Server (NTRS)

    Bell, J. F., III (Editor); Moersch, J. E. (Editor)

    1995-01-01

    The Mars Telescopic Observations Workshop, held August 14-15, 1995, at Cornell University in Ithaca, New York, was organized and planned with two primary goals in mind: The first goal was to facilitate discussions among and between amateur and professional observers and to create a workshop environment fostering collaborations and comparisons within the Mars observing community. The second goal was to explore the role of continuing telescopic observations of Mars in the upcoming era of increased spacecraft exploration. The 24 papers presented at the workshop described the current NASA plans for Mars exploration over the next decade, current and recent Mars research being performed by professional astronomers, and current and past Mars observations being performed by amateur observers and observing associations. The workshop was divided into short topical sessions concentrating on programmatic overviews, groundbased support of upcoming spacecraft experiments, atmospheric observations, surface observations, modeling and numerical studies, and contributions from amateur astronomers.

  10. The Space Surveillance Telescope: Focus and Alignment of a Three Mirror Telescope

    NASA Astrophysics Data System (ADS)

    Woods, D.; Shah, R.; Johnson, J.; Szabo, A.; Pearce, E.; Lambour, R.; Faccenda, W.

    2012-09-01

    The Space Surveillance Telescope (SST) is a DARPA-funded technology initiative to dramatically increase sensitivity to microsatellites at the geosynchronous belt and to improve cataloging of the deep space resident space object (RSO) population. The SST achieves increased sensitivity to faint objects and rapid search capabilities by combining a large 3.5-meter aperture Mersenne-Schmidt telescope design and a highly sensitive curved mosaic focal surface CCD camera. While the unique system design is advantageous for space surveillance capabilities, it presents a challenge to alignment due to an inherently small depth of focus and the additional degrees of freedom introduced with a powered tertiary mirror. This paper will provide a brief overview of the SST, discuss the methodology for achieving and maintaining focus and alignment of the system across a range of temperature and elevation conditions, and present recent results of the system alignment performance. This work is sponsored by the Defense Advanced Research Projects Agency under Air Force Contract #FA8721-05-C-0002. Opinions, interpretations, conclusions and recommendations are those of the author and are not necessarily endorsed by the United States Government. Distribution Statement A: Distribution is Unlimited

  11. The James Webb Space Telescope

    NASA Technical Reports Server (NTRS)

    Gardner, Jonathan P.

    2011-01-01

    The James Webb Space Telescope is the scientific successor to the Hubble and Spitzer Space Telescopes, and is currently the largest scientific project under construction in the United States. It will be a large (6.6m) cold (50K) telescope launched in about 5 years into orbit around the second Earth-Sun Lagrange point. It is a partnership of NASA with the European and Canadian Space Agencies. Science with the James Webb Space Telescope falls into four themes. The End of the Dark Ages: First Light and Reionization theme seeks to identify the first luminous sources to form and to determine the ionization history of the universe. The Assembly of Galaxies theme seeks to determine how galaxies and the dark matter, gas, stars, metals, morphological structures, and black holes within them evolved from the epoch of reionization to the present. The Birth of Stars and Protoplanetary Systems theme seeks to unravel the birth and early evolution of stars, from infall onto dust-enshrouded protostars, to the genesis of planetary systems. The Planetary Systems and the Origins of Life theme seeks to determine the physical and chemical properties of planetary systems around nearby stars and of our own, and investigate the potential for life in those systems. Webb will have four instruments: The Near-Infrared Camera, the Near-Infrared multi-object Spectrograph, and the Tunable Filter Imager will cover the wavelength range 0.6 to 5 microns, while the Mid-Infrared Instrument will do both imaging and spectroscopy from 5 to 28.5 microns. I will conclude the talk with a description of recent technical progress in the construction of the observatory.

  12. The James Webb Space Telescope

    NASA Technical Reports Server (NTRS)

    Gardner, Jonathan P.

    2011-01-01

    The James Webb Space Telescope is the scientific successor to the Hubble and Spitzer Space Telescopes, and is currently the largest scientific project under construction in the United States. It will be a large (6.6m) cold (50K) telescope launched into orbit around the second Earth-Sun Lagrange point. It is a partnership of NASA with the European and Canadian Space Agencies. Science with the James Webb Space Telescope falls into four themes. The End of the Dark Ages: First Light and Reionization theme seeks to identify the first luminous sources to form and to determine the ionization history of the universe. The Assembly of Galaxies theme seeks to determine how galaxies and the dark matter, gas, stars, metals, morphological structures, and black holes within them evolved from the epoch of reionization to the present. The Birth of Stars and Protoplanetary Systems theme seeks to unravel the birth and early evolution of stars, from infall onto dust-enshrouded protostars, to the genesis of planetary systems. The Planetary Systems and the Origins of Life theme seeks to determine the physical and chemical properties of planetary systems around nearby stars and of our own, and investigate the potential for life in those systems. Webb will have four instruments: The Near-Infrared Camera, the Near-Infrared multi-object Spectrograph, and the Tunable Filter Imager will cover the wavelength range 0.6 to 5 microns, while the Mid-Infrared Instrument will do both imaging and spectroscopy from 5 to 28.5 microns. I will conclude the talk with a description of recent technical progress in the construction of the observatory.

  13. Opening the Dutch Open Telescope

    NASA Astrophysics Data System (ADS)

    Rutten, R. J.; de Wijn, A. G.; Sütterlin, P.; Bettonvil, F. C. M.; Hammerschlag, R. H.

    2002-10-01

    We hope to "open the DOT" to the international solar physics community as a facility for high-resolution tomography of the solar atmosphere. Our aim is to do so combining peer-review time allocation with service-mode operation in a "hands-on-telescope" education program bringing students to La Palma to assist in the observing and processing. The largest step needed is considerable speedup of the DOT speckle processing.

  14. The James Webb Space Telescope

    NASA Technical Reports Server (NTRS)

    Gardner, Jonathan P.

    2011-01-01

    The James Webb Space Telescope is the scientific successor to the Hubble and Spitzer Space Telescopes, and is currently the largest scientific project under construction in the United States. It will be a large (6.6m) cold (50K) telescope launched in about 5 years into orbit around the second Earth-Sun Lagrange point. It is a partnership of NASA with the European and Canadian Space Agencies. Science with the James Webb Space Telescope falls into four themes. The End of the Dark Ages: First Light and Reionization theme seeks to identify the first luminous sources to form and to determine the ionization history of the universe. The Assembly of Galaxies theme seeks to determine how galaxies and the dark matter, gas, stars, metals, morphological structures, and black holes within them evolved from the epoch of reionization to the present. The Birth of Stars and Proto planetary Systems theme seeks to unravel the birth and early evolution of stars, from infall onto dust-enshrouded protostars, to the genesis of planetary systems. The Planetary Systems and the Origins of Life theme seeks to determine the physical and chemical properties of planetary systems around nearby stars and of our own, and investigate the potential for life in those systems. Webb will have four instruments: The Near-Infrared Camera, the Near-Infrared multi-object Spectrograph, and the Tunable Filter Imager will cover the wavelength range 0.6 to 5 microns, while the Mid-Infrared Instrument will do both imaging and spectroscopy from 5 to 28.5 microns. I will conclude the talk with a description of recent technical progress in the construction of the observatory.

  15. Building the Green Bank Telescope

    NASA Astrophysics Data System (ADS)

    Kellermann, Kenneth I.

    2017-01-01

    In a previous presentation, I reported on how the freak collapse of the NRAO 300-ft transit radio telescope led to the inclusion of $75 million for a new radio telescope in the 1989 Congressional Emergency Supplemental Appropriations Act. But, this was only the beginning. NRAO was faced with challenging specifications and an unworkable schedule, but there was no design and no project team. Only one bid was even close to the Congressional appropriation. In an attempt to meet the unrealistic antenna delivery date, the contractor started construction of the foundation and fabrication of antenna members before the design was finished, leading to retrofits, redesign, and multiple delays. The antenna contractor was twice sold to other companies leading to further delays and cost escalation. In order to recoup their mounting losses, the new owners sued NRAO for $29 million for claimed design changes, and NRAO countersued demanding to be reimbursed for added project management costs and lost scientific data resulting from the seven-year delay in the completion of the telescope. Legal fees and a small net award in favor of the contractor left NRAO and the NSF with a nine million dollar bill which NSF handled by an innovative accounting adjustment.

  16. The James Webb Space Telescope

    NASA Technical Reports Server (NTRS)

    Nowak, Maria; Eichorn, William; Hill, Michael; Hylan, Jason; Marsh, James; Ohl, Raymond; Sampler, Henry; Wright, Geraldine; Crane, Allen; Herrera, Acey; Quigley, Robert; Jetten, Mark; Young, Philip

    2007-01-01

    The James Webb Space Telescope (JWST) is a 6.6m diameter, segmented, deployable telescope for cryogenic IR space astronomy (approx.40K). The JWST Observatory architecture includes the Optical Telescope Element and the Integrated Science Instrument Module (ISIM) element that contains four science instruments (SI) including a Guider. The ISIM optical metering structure is a roughly 2.2x1.7x2.2mY, asymmetric frame that is composed of carbon fiber and resin tubes bonded to invar end fittings and composite gussets and clips. The structure supports the SIs, isolates the SIs from the OTE, and supports thermal and electrical subsystems. The structure is attached to the OTE structure via strut-like kinematic mounts. The ISM structure must meet its requirements at the approx.40K cryogenic operating temperature. The SIs are aligned to the structure s coordinate system under ambient, clean room conditions using laser tracker and theodolite metrology. The ISM structure is thermally cycled for stress relief and in order to measure temperature-induced mechanical, structural changes. These ambient-to-cryogenic changes in the alignment of SI and OTE-related interfaces are an important component in the JWST Observatory alignment plan and must be verified.

  17. The James Webb Space Telescope

    NASA Technical Reports Server (NTRS)

    Gardner, Jonathan P.

    2012-01-01

    The James Webb Space Telescope is the scientific successor to the Hubble and Spitzer Space Telescopes. It will be a large (6.6m) cold (SDK) telescope launched into orbit around the second Earth-Sun Lagrange point. It is a partnership of NASA with the European and Canadian Space Agencies. The science goals for JWST include the formation of the first stars and galaxies in the early universe; the chemical, morphological and dynamical buildup of galaxies and the formation of stars and planetary systems. Recently, the goals have expanded to include studies of dark energy, dark matter, active galactic nuclei, exoplanets and Solar System objects. Webb will have four instruments: The Near-Infrared Camera, the Near-Infrared multi-object Spectrograph, and the Near-Infrared Imager and Slitless Spectrograph will cover the wavelength range 0.6 to S microns, while the Mid-Infrared Instrument will do both imaging and spectroscopy from 5 to 28.5 microns. The observatory is confirmed for launch in 2018; the design is complete and it is in its construction phase. Recent progress includes the completion of the mirrors, the delivery of the first flight instruments and the start of the integration and test phase.

  18. Sensitivity of coded mask telescopes

    SciTech Connect

    Skinner, Gerald K

    2008-05-20

    Simple formulas are often used to estimate the sensitivity of coded mask x-ray or gamma-ray telescopes, but these are strictly applicable only if a number of basic assumptions are met. Complications arise, for example, if a grid structure is used to support the mask elements, if the detector spatial resolution is not good enough to completely resolve all the detail in the shadow of the mask, or if any of a number of other simplifying conditions are not fulfilled. We derive more general expressions for the Poisson-noise-limited sensitivity of astronomical telescopes using the coded mask technique, noting explicitly in what circumstances they are applicable. The emphasis is on using nomenclature and techniques that result in simple and revealing results. Where no convenient expression is available a procedure is given that allows the calculation of the sensitivity. We consider certain aspects of the optimization of the design of a coded mask telescope and show that when the detector spatial resolution and the mask to detector separation are fixed, the best source location accuracy is obtained when the mask elements are equal in size to the detector pixels.

  19. QUIJOTE telescope design and fabrication

    NASA Astrophysics Data System (ADS)

    Gomez, Alberto; Murga, Gaizka; Etxeita, Borja; Sanquirce, Rubén; Rebolo, Rafael; Rubiño-Martin, Jose Alberto; Herreros, José-Miguel; Hoyland, Roger; Gomez, Francisca; Génova-Santos, Ricardo T.; Piccirillo, Lucio; Maffei, Bruno; Watson, Robert

    2010-07-01

    The QUIJOTE CMB experiment aims to characterize the polarization of the CMB in the frequency range 10-30 GHz and large angular scales. It will be installed in the Teide Observatory, following the projects that the Anisotropy of the Cosmic Microwave Background group has developed in the past (Tenerife experiment, IAC-Bartol experiment...) and is running at the present time (VSA, Cosmosomas). The QUIJOTE CMB experiment will consist of two telescopes which will be installed inside a unique enclosure, which is already constructed. The layout of both telescopes is based on an altazimuth mount supporting a primary and a secondary mirror disposed in a offset Gregorian Dragon scheme. The use of industrial-like fabrication techniques, such as sand-mould casting, CNC machining, and laser tracker measuring for alignment, provided the required performances for microwave observation. A fast-track construction scheme, altogether with the use of these fabrication techniques allowed designing and manufacturing the opto-mechanics of the telescope in 14 months prior to delivery for final start-up in December 2008.

  20. CMB Telescopes and Optical Systems

    NASA Astrophysics Data System (ADS)

    Hanany, Shaul; Niemack, Michael D.; Page, Lyman

    The cosmic microwave background radiation (CMB) is now firmly establishedas a fundamental and essential probe of the geometry, constituents, and birth ofthe observable universe. The CMB is a potent observable because it can bemeasured with precision and accuracy. Just as importantly, theoretical models ofthe universe can predict the characteristics of the CMB to high accuracy, andthose predictions can be directly compared to observations. There are multipleaspects associated with making a precise measurement. In this chapter, we focuson optical components for the instrumentation used to measure the CMBpolarization and temperature anisotropy. We begin with an overview of generalconsiderations for CMB observations and discuss common concepts used inthe community. We next consider a variety of alternatives available for adesigner of a CMB telescope. Our discussion is guided by the ground- andballoon-based instruments that have been implemented over the years. In thesame vein, we compare the arc-minute resolution Atacama CosmologyTelescope (ACT) and the South Pole Telescope (SPT). CMB interferometersare presented briefly. We conclude with a comparison of the four CMBsatellites, Relikt, COBE, WMAP, and Planck, to demonstrate a remarkableevolution in design, sensitivity, resolution, and complexity over the past30 years.

  1. The NASA Spitzer Space Telescope.

    PubMed

    Gehrz, R D; Roellig, T L; Werner, M W; Fazio, G G; Houck, J R; Low, F J; Rieke, G H; Soifer, B T; Levine, D A; Romana, E A

    2007-01-01

    The National Aeronautics and Space Administration's Spitzer Space Telescope (formerly the Space Infrared Telescope Facility) is the fourth and final facility in the Great Observatories Program, joining Hubble Space Telescope (1990), the Compton Gamma-Ray Observatory (1991-2000), and the Chandra X-Ray Observatory (1999). Spitzer, with a sensitivity that is almost three orders of magnitude greater than that of any previous ground-based and space-based infrared observatory, is expected to revolutionize our understanding of the creation of the universe, the formation and evolution of primitive galaxies, the origin of stars and planets, and the chemical evolution of the universe. This review presents a brief overview of the scientific objectives and history of infrared astronomy. We discuss Spitzer's expected role in infrared astronomy for the new millennium. We describe pertinent details of the design, construction, launch, in-orbit checkout, and operations of the observatory and summarize some science highlights from the first two and a half years of Spitzer operations. More information about Spitzer can be found at http://spitzer.caltech.edu/.

  2. Sensitivity of coded mask telescopes.

    PubMed

    Skinner, Gerald K

    2008-05-20

    Simple formulas are often used to estimate the sensitivity of coded mask x-ray or gamma-ray telescopes, but these are strictly applicable only if a number of basic assumptions are met. Complications arise, for example, if a grid structure is used to support the mask elements, if the detector spatial resolution is not good enough to completely resolve all the detail in the shadow of the mask, or if any of a number of other simplifying conditions are not fulfilled. We derive more general expressions for the Poisson-noise-limited sensitivity of astronomical telescopes using the coded mask technique, noting explicitly in what circumstances they are applicable. The emphasis is on using nomenclature and techniques that result in simple and revealing results. Where no convenient expression is available a procedure is given that allows the calculation of the sensitivity. We consider certain aspects of the optimization of the design of a coded mask telescope and show that when the detector spatial resolution and the mask to detector separation are fixed, the best source location accuracy is obtained when the mask elements are equal in size to the detector pixels.

  3. Equal-Curvature X-Ray Telescopes

    NASA Technical Reports Server (NTRS)

    Saha, Timo T.; Zhang, William

    2002-01-01

    We introduce a new type of x-ray telescope design; an Equal-Curvature telescope. We simply add a second order axial sag to the base grazing incidence cone-cone telescope. The radius of curvature of the sag terms is the same on the primary surface and on the secondary surface. The design is optimized so that the on-axis image spot at the focal plane is minimized. The on-axis RMS (root mean square) spot diameter of two studied telescopes is less than 0.2 arc-seconds. The off-axis performance is comparable to equivalent Wolter type 1 telescopes.

  4. Cost Modeling for Space Optical Telescope Assemblies

    NASA Technical Reports Server (NTRS)

    Stahl, H. Philip; Henrichs, Todd; Luedtke, Alexander; West, Miranda

    2011-01-01

    Parametric cost models are used to plan missions, compare concepts and justify technology investments. This paper reviews an on-going effort to develop cost modes for space telescopes. This paper summarizes the methodology used to develop cost models and documents how changes to the database have changed previously published preliminary cost models. While the cost models are evolving, the previously published findings remain valid: it costs less per square meter of collecting aperture to build a large telescope than a small telescope; technology development as a function of time reduces cost; and lower areal density telescopes cost more than more massive telescopes.

  5. Wavefront Analysis of Adaptive Telescope

    NASA Technical Reports Server (NTRS)

    Hadaway, James B.; Hillman, Lloyd

    1997-01-01

    The motivation for this work came from a NASA Headquarters interest in investigating design concepts for a large space telescope employing active optics technology. Current and foreseeable launch vehicles will be limited to carrying around 4-5 meter diameter objects. Thus, if a large, filled-aperture telescope (6-20 meters in diameter) is to be placed in space, it will be required to have a deployable primary mirror. Such a mirror may be an inflatable membrane or a segmented mirror consisting of many smaller pieces. In any case, it is expected that the deployed primary will not be of sufficient quality to achieve diffraction-limited performance for its aperture size. Thus, an active optics system will be needed to correct for initial as well as environmentally-produced primary figure errors. Marshall Space Flight Center has developed considerable expertise in the area of active optics with the PAMELA test-bed. The combination of this experience along with the Marshall optical shop's work in mirror fabrication made MSFC the logical choice to lead NASA's effort to develop active optics technology for large, space-based, astronomical telescopes. Furthermore, UAH's support of MSFC in the areas of optical design, fabrication, and testing of space-based optical systems placed us in a key position to play a major role in the development of this future-generation telescope. A careful study of the active optics components had to be carried out in order to determine control segment size, segment quality, and segment controllability required to achieve diffraction-limited resolution with a given primary mirror. With this in mind, UAH undertook the following effort to provide NASA/MSFC with optical design and analysis support for the large telescope study. All of the work performed under this contract has already been reported, as a team member with MSFC, to NASA Headquarters in a series of presentations given between May and December of 1995. As specified on the delivery

  6. Twin-Telescope Wettzell (TTW)

    NASA Astrophysics Data System (ADS)

    Hase, H.; Dassing, R.; Kronschnabl, G.; Schlüter, W.; Schwarz, W.; Lauber, P.; Kilger, R.

    2007-07-01

    Following the recommendations made by the VLBI2010 vision report of the IVS, a proposal has been made to construct a Twin Telescope for the Fundamental Station Wettzell in order to meet the future requirements of the next VLBI generation. The Twin Telescope consists of two identical radiotelescopes. It is a project of the Federal Agency for Cartography and Geodesy (BKG). This article summarizes the project and some design ideas for the Twin-Telescope. %ZALMA (2005). Technical Specification for Design, Manufacturing, Transport and Integration on Site of the ALMA ANTENNAS, Doc. ALMA-34.00.00.00.006-BSPE. Behrend, D. (2006). VLBI2010 Antenna Specs, Data sheet. DeBoer, D. (2001). The ATA Offset Gregorian Antenna, ATA Memo #16, February 10. Imbriale, W.A. (2006). Design of a Wideband Radio Telescope, Jet Propulsion Laboratory and S. Weinreb and H. Mandi, California Institute of Technology. Kilger, R. (2007). TWIN-Design studies, Presentation for the IVS board members (internal document),Wettzell. Kronschnabl, G. (2006). Subject: Memo from Bill Petrachenko, E-mail to the Twin-Working Group (in German), July. Lindgren, ETS-Lindgren (2005). The Model 3164-05 Open Boundary Quadridge Horn, Data Sheet. Niell, A., A. Whitney, W. Petrachenko, W. Schlüter, N. Vandenberg, H.Hase, Y. Koyama, C. Ma, H. Schuh, G. Tucari (2006). in: IVS Annual Report 2005, pg. 13-40, NASA/TP-2006-214136, April. Olsson, R., Kildal, P.-S., and Weinreb, S. (2006). IEEE Transactions on Antennas and Propagation, Vol. 54, No. 2, February. Petrachenko, B. (2006). The Case For and Against Multiple Antennas at a Site, IVS Memorandum, 2006-019v01. Petrachenko, B. (2006). IVS Memorandum, 2006-016v01. RFSpin (2004). Double Ridged Waveguide Horn-Model DRH20, Antenna Specifications, Data Sheet. Rohde&Schwarz (2004). SHF Antennas Crossed Log- Periodic Antennas HL024A1/S1, Data Sheet. Rohde&Schwarz (2004). SHF Antennas Log-Periodic Antennas HL050/HL050S1, Data Sheet. Rogers, A.E.E. (2006). Simulations of broadband

  7. M Dwarf Exoplanet Survey by the Falcon Telescope Network

    NASA Astrophysics Data System (ADS)

    Carlson, Randall E.

    2016-10-01

    The Falcon Telescope Network (FTN) consists of twelve automated 20-inch telescopes located around the globe. We control it at the US Air Force Academy in Colorado Springs, Colorado from the Cadet Space Operations Center. We have installed 10 of the 12 sites and anticipate full operational capability by the beginning of 2017. The network's worldwide geographic distribution provides advantages. The primary mission of the FTN is Space Situational Awareness and studying Near Earth Objects. However, we are employing the FTN with its 11' x 11' field-of-view for a five-year, M dwarf exoplanet survey. Specifically, we are searching for Earth-radius exoplanets. We describe the FTN, design considerations going into the FTN's M dwarf exoplanet survey including automated operations, and initial results of the survey.

  8. Infiltration of supermicron aerosols into a simulated space telescope

    NASA Astrophysics Data System (ADS)

    Liu, De-Ling; Luey, Kenneth T.

    2010-08-01

    Purging is a common scheme to protect sensitive surfaces of payloads and spacecraft from airborne contaminant intrusion during ground assembly, integration, and launch vehicle encapsulation. However, the purge for space volumes must be occasionally interrupted. Thus it is important to gain insights into the transport of ambient particles penetrating through vent holes and entering the interior of a confined space system, such as a space telescope, during a purge outage. This study presents experimental work performed to measure time-dependent aerosol concentration changes during a purge outage. The laboratory results from the aerosol experiments were compared with a mass balance based mechanistic model which had been experimentally validated for aerosols ranging from 0.5 to 2 μm. The experimental data show that the steady-state aerosol concentration inside a simulated space telescope (SST) is governed by the surrounding particle concentration, SST air exchange rate, and the particle deposition rate.

  9. Hubble Space Telescope: The Telescope, the Observations & the Servicing Mission

    NASA Astrophysics Data System (ADS)

    1999-11-01

    Today the HST Archives contain more than 260 000 astronomical observations. More than 13 000 astronomical objects have been observed by hundreds of different groups of scientists. Direct proof of the scientific significance of this project is the record-breaking number of papers published : over 2400 to date. Some of HST's most memorable achievements are: * the discovery of myriads of very faint galaxies in the early Universe, * unprecedented, accurate measurements of distances to the farthest galaxies, * significant improvement in the determination of the Hubble constant and thus the age of the Universe, * confirmation of the existence of blacks holes, * a far better understanding of the birth, life and death of stars, * a very detailed look at the secrets of the process by which planets are created. Europe and HST ESA's contribution to HST represents a nominal investment of 15%. ESA provided one of the two imaging instruments - the Faint Object Camera (FOC) - and the solar panels. It also has 15 scientists and computer staff working at the Space Telescope Science Institute in Baltimore (Maryland). In Europe the astronomical community receives observational assistance from the Space Telescope European Coordinating Facility (ST-ECF) located in Garching, Munich. In return for ESA's investment, European astronomers have access to approximately 15% of the observing time. In reality the actual observing time competitively allocated to European astronomers is closer to 20%. Looking back at almost ten years of operation, the head of ST-ECF, European HST Project Scientist Piero Benvenuti states: "Hubble has been of paramount importance to European astronomy, much more than the mere 20% of observing time. It has given the opportunity for European scientists to use a top class instrument that Europe alone would not be able to build and operate. In specific areas of research they have now, mainly due to HST, achieved international leadership." One of the major reasons for

  10. Aligning Astronomical Telescopes via Identification of Stars

    NASA Technical Reports Server (NTRS)

    Whorton, Mark

    2010-01-01

    A proposed method of automated, precise alignment of a ground-based astronomical telescope would eliminate the need for initial manual alignment. The method, based on automated identification of known stars and other celestial objects in the telescope field of view, would also eliminate the need for an initial estimate of the aiming direction. The method does not require any equipment other than a digital imaging device such as a charge-coupled-device digital imaging camera and control computers of the telescope and camera, all of which are standard components in professional astronomical telescope systems and in high-end amateur astronomical telescope systems. The method could be implemented in software running in the telescope or camera control computer or in an external computer communicating with the telescope pointing mount and camera control computers.

  11. Physics and astrophysics with gamma-ray telescopes

    NASA Astrophysics Data System (ADS)

    Vandenbroucke, J.; Fermi LAT Collaboration

    2012-08-01

    In the past few years gamma-ray astronomy has entered a golden age. A modern suite of telescopes is now scanning the sky over both hemispheres and over six orders of magnitude in energy. At ˜TeV energies, only a handful of sources were known a decade ago, but the current generation of ground-based imaging atmospheric Cherenkov telescopes (H.E.S.S., MAGIC, and VERITAS) has increased this number to nearly one hundred. With a large field of view and duty cycle, the Tibet and Milagro air shower detectors have demonstrated the promise of the direct particle detection technique for TeV gamma rays. At ˜GeV energies, the Fermi Gamma-ray Space Telescope has increased the number of known sources by nearly an order of magnitude in its first year of operation. New classes of sources that were previously theorized to be gamma-ray emitters have now been confirmed observationally. Moreover, there have been surprise discoveries of GeV gamma-ray emission from source classes for which no theory predicted it was possible. In addition to elucidating the processes of high-energy astrophysics, gamma-ray telescopes are making essential contributions to fundamental physics topics including quantum gravity, gravitational waves, and dark matter. I summarize the current census of astrophysical gamma-ray sources, highlight some recent discoveries relevant to fundamental physics, and describe the synergetic connections between gamma-ray and neutrino astronomy. This is a brief overview intended in particular for particle physicists and neutrino astronomers, based on a presentation at the Neutrino 2010 conference in Athens, Greece. I focus in particular on results from Fermi (which was launched soon after Neutrino 2008), and conclude with a description of the next generation of instruments, namely HAWC and the Cherenkov Telescope Array.

  12. Telescope Array UHECR composition measurement via stereoscopic fluorescence observation

    NASA Astrophysics Data System (ADS)

    Stroman, Thomas; Bergman, Douglas; Telescope Array Collaboration

    2016-03-01

    When entering Earth's atmosphere at ultra-high energies, cosmic rays (UHECRs) produce extensive air showers whose longitudinal development is influenced by the incident primary particle's mass. Each longitudinal shower profile reaches its maximum particle count at an atmospheric slant depth Xmax, and the distributions of observed Xmax values can be compared to those predicted by detailed simulations of the air-shower physics and the detector; accurately simulated compositions that most closely resemble that found in nature will produce the best agreement between predicted and observed Xmax distributions. This is the basis of composition measurement at the Telescope Array experiment, the largest and most sensitive UHECR detector in the northern hemisphere. At the perimeter of a large surface-detector array are three fluorescence telescope stations, whose overlapping apertures enable high-precision reconstruction of Xmax from stereoscopic observation of air-shower longitudinal profiles. We present the distribution of Xmax observed during eight years of operation, and from comparisons with several simulated combinations of composition and high-energy hadronic physics, we show that a low primary mass is favored at E >10 18 . 2 eV.

  13. Lightning Detection at the Telescope Array Cosmic Ray Observatory

    NASA Astrophysics Data System (ADS)

    Takai, Helio; Belz, John; Thomson, Gordon; Hanlon, William; Rison, Bill; Thomas, Ron; Krehbiel, Paul; Okuda, Takeshi

    2014-03-01

    It is known that the electric fields measured in lightning clouds are an order of magnitude too small than the critical electric field required for dielectric breakdown of air, there are therefore unknown mechanisms at work which initiate lightning. One theory is that cosmic ray air showers can initiate lightning via a runaway breakdown process. To study this problem, 10 VHF lightning monitoring stations built by New Mexico Tech were deployed at the Telescope Array site on September 2013. If cosmic rays act as lightning initiators, then the TA surface detectors may be able to detect high energy particles from the associated air shower while the NMT lightning detectors simultaneously measure VHF radio pulses of the lightning discharges themselves. The Telescope Array is the largest cosmic ray observatory in the Northern hemisphere. Located in Millard County, Utah, it covers an area of 750 km2. The VHF monitoring stations can be used to produce 3D images of the lightning strikes. Using both setups we hope to be able to investigate in detail the role of cosmic rays in lightning, or if there is any gamma ray production from lightning activity. We will discuss how a collaboration between TA, NMT and BNL can help in understanding of a long standing mysteries about lightning formation. Results of data analysis for events that were observed in coincidence between our detectors will be presented.

  14. The Northwest Indiana Robotic Telescope

    NASA Astrophysics Data System (ADS)

    Slavin, Shawn D.; Rengstorf, A. W.; Aros, J. C.; Segally, W. B.

    2011-01-01

    The Northwest Indiana Robotic (NIRo) Telescope is a remote, automated observing facility recently built by Purdue University Calumet (PUC) at a site in Lowell, IN, approximately 30 miles from the PUC campus. The recently dedicated observatory will be used for broadband and narrowband optical observations by PUC students and faculty, as well as pre-college students through the implementation of standards-based, middle-school modules developed by PUC astronomers and education faculty. The NIRo observatory and its web portal are the central technical elements of a project to improve astronomy education at Purdue Calumet and, more broadly, to improve science education in middle schools of the surrounding region. The NIRo Telescope is a 0.5-meter (20-inch) Ritchey-Chrétien design on a Paramount ME robotic mount, featuring a seven-position filter wheel (UBVRI, Hα, Clear), Peltier (thermoelectrically) cooled CCD camera with 3056 x 3056, square, 12 μm pixels, and off-axis guiding. It provides a coma-free imaging field of 0.5 degrees square, with a plate scale of 0.6 arcseconds per pixel. The observatory has a wireless internet connection, local weather station which publishes data to an internet weather site, and a suite of CCTV security cameras on an IP-based, networked video server. Control of power to every piece of instrumentation is maintained via internet-accessible power distribution units. The telescope can be controlled on-site, or off-site in an attended fashion via an internet connection, but will be used primarily in an unattended mode of automated observation, where queued observations will be scheduled daily from a database of requests. Completed observational data from queued operation will be stored on a campus-based server, which also runs the web portal and observation database. Partial support for this work was provided by the National Science Foundation's Course, Curriculum, and Laboratory Improvement (CCLI) program under Award No. 0736592.

  15. The James Webb Space Telescope

    NASA Technical Reports Server (NTRS)

    Gardner, Jonathan P.

    2007-01-01

    The scientific capabilities of the James Webb Space Telescope (JWST) fall into four themes. The End of the Dark Ages: First Light and Reionization theme seeks to identify the first luminous sources to form and to determine the ionization history of the universe. The Assembly of Galaxies theme seeks to determine how galaxies and the dark matter, gas, stars, metals, morphological structures, and active nuclei within them evolved from the epoch of reionization to the present. The Birth of Stars and Protoplanetary Systems theme seeks to unravel the birth and early evolution of stars, from infall onto dust-enshrouded protostars, to the genesis of planetary systems. The Planetary Systems and the Origins of Life theme seeks to determine the physical and chemical properties of planetary systems around nearby stars and of our own, and investigate the potential for life in those systems. To enable these four science themes, JWST will be a large (6.6m) cold (50K) telescope launched to the second Earth-Sun Lagrange point early in the next decade. It is the successor to the Hubble Space Telescope, and is a partnership of NASA, ESA and CSA. JWST will have four instruments: The Near-Infrared Camera, the Near-Infrared multi-object Spectrograph, and the Tunable Filter Imager will cover the wavelength range 0.6 to 5 microns, while the Mid-Infrared Instrument will do both imaging and spectroscopy from 5 to 28.5 microns. In this paper, the status and capabilities of the observatory and instruments in the context of the major scientific goals are reviewed.

  16. Air Research

    EPA Pesticide Factsheets

    EPA's air research provides the critical science to develop and implement outdoor air regulations under the Clean Air Act and puts new tools and information in the hands of air quality managers and regulators to protect the air we breathe.

  17. Space Telescope precision pointing control system

    NASA Technical Reports Server (NTRS)

    Beals, G. A.; Crum, R. C.; Dougherty, H. J.; Hegel, D. K.; Kelley, J. L.

    1986-01-01

    The Hubble Space Telescope has the most stringent pointing requirements imposed on any spacecraft to date. The overall HST stability shall not exceed 0.007 arc-seconds rms. The Pointing Control System utilizes fine guidance sensors and rate gyros for attitude reference and rate information. Control torques are provided by reaction wheels. A digital computer collects the sensor data, performs the control law computations, and sends torque commands to the reaction wheels. To attain this precision pointing, improvements were made to the rate gyros to lower their noise characteristics and to the reaction wheels to reduce their emitted vibration levels. The control system design was validated in a test sequence which progressed from model verification tests on an air-bearing to operations-oriented, closed loop testing on the assembled vehicle. A test system is described which allowed the simultaneous production of test case command loads for the flight computer and plots of predicted profiles to assist in test data analysis. Workarounds were required during system test to accommodate gyro biases and noise introduced into the closed loop system. Testing and analysis indicate that the HST will provide the capability to meet the requirements for precision pointing.

  18. Hubble Space Telescope battery background

    NASA Technical Reports Server (NTRS)

    Standlee, Dan

    1991-01-01

    The following topics are presented in viewgraph form and include the following: the MSFC Hubble Space Telescope (HST) Nickel-Hydrogen Battery Contract; HST battery design requirements; HST nickel-hydrogen battery development; HST nickel-hydrogen battery module; HST NiH2 battery module hardware; pressure vessel design; HST NiH2 cell design; offset non-opposing vs. rabbit ear cell; HST NiH2 specified capacity; HST NiH2 battery design; and HST NiH2 module design.

  19. The 1.3-m Robotically Controlled Telescope (RCT) at Kitt Peak - A Fifty year old dream Realized: Telescope Characteristics, Current Research and Education Progr

    NASA Astrophysics Data System (ADS)

    Guinan, Edward; Gelderman, Richard; Strolger, Louis-Gregory; Carini, Michael T.; McGruder, Charles, III; Campbell, Rachel; Walter, Donald K.; Davis, Donald R.; Tedesco, Edward F.; Engle, Scott G.

    2011-03-01

    The 1.3 m Robotically Controlled Telescope (RCT) on Kitt Peak has a rich history, including its role as a prototype for remotely controlled telescopes during the 1960s. As such, the RCT could be considered one of the first - Telescopes from Afar. The telescope, originally called the Remotely Controlled Telescope, has been renamed the Robotically Controlled Telescope to reflect the change in operational control and mode of use. The RCT was a conceptual precursor of today's robotic telescopes, but the actual operation of a remotely controlled telescope was technologically premature for its time, and was subsequently manually operated primarily to conduct optical and infrared observations as well being used as a test bed for new spectroscopic and photometric instruments. In 1995 budget constraints forced the closing of the telescope as part of the Kitt Peak National Observatory (KPNO), following nearly 30 years of distinguished service to KPNO. A request for proposals to operate this telescope was issued to the science community. The RCT consortium, lead by Western Kentucky University, was the successful proposer for operation of the telescope. After several difficult years of retrofitting, refurbishing, and automating the telecope and observatory dome, the telescope has returned to routine science operations in November 2009. The RCT has operated smoothly since that time, with no major interruptions. Observations of objects of interest to the consortium partners (including: comets & asteroids, variable & binary stars, exoplanets, supernovae, quasars & blazars) are being routinely obtained and evaluated. One of the distinguishing features of the RCT is that it is an autonomous observatory designed to handle diverse optical imaging and photometry programs. These include being able to automatically deal with a wide range of observing parameters such as -integration time, sky conditions, repetitions, return visits, filters, air mass, non-sidereal objects, transients etc

  20. Broad Band X-Ray Telescope (BBXRT) Work Station in the Spacelab Payload Operations Control Center

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The primary objective of the STS-35 mission was round the clock observation of the celestial sphere in ultraviolet and X-Ray astronomy with the Astro-1 observatory which consisted of four telescopes: the Hopkins Ultraviolet Telescope (HUT); the Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE); the Ultraviolet Imaging Telescope (UIT); and the Broad Band X-Ray Telescope (BBXRT). The Huntsville Operations Support Center (HOSC) Spacelab Payload Operations Control Center (SL POCC) at the Marshall Space Flight Center (MSFC) was the air/ground communication channel used between the astronauts and ground control teams during the Spacelab missions. Teams of controllers and researchers directed on-orbit science operations, sent commands to the spacecraft, received data from experiments aboard the Space Shuttle, adjusted mission schedules to take advantage of unexpected science opportunities or unexpected results, and worked with crew members to resolve problems with their experiments. Due to loss of data used for pointing and operating the ultraviolet telescopes, MSFC ground teams were forced to aim the telescopes with fine tuning by the flight crew. This photo captures the activity of WUPPE (Wisconsin Ultraviolet Photo-Polarimeter Experiment) data review at the Science Operations Area during the mission. This image shows mission activities at the Broad Band X-Ray Telescope (BBXRT) Work Station in the Science Operations Area (SOA).

  1. Extremely large telescope: a twenty-five meter aperture for the twenty-first century

    NASA Astrophysics Data System (ADS)

    Bash, Frank N.; Sebring, Thomas A.; Ray, Frank B.; Ramsey, Lawrence W.

    1997-03-01

    The 10-meter class Hobby-Eberly telescope (HET), now nearing completion, provides technology for optical Arecibo-type telescopes which can be extrapolated to even larger apertures. Utilizing a fixed elevation angle and a spherical segmented primary mirror provides cost effective and pragmatic solutions to mirror mounting and fabrication. Arecibo-type tracking implies a greatly reduced tracking mass and no change to the gravity vector for the primary mirror. Such a telescope can address 70 percent of the available sky and exhibit optical quality easily sufficient for effective spectroscopy and photometry. The extremely large telescope takes advantage of several key engineering approaches demonstrated by the HET project to achieve a cost comparable to similarly-sized radio rather than optical telescopes. These engineering approaches include: bolted pre-manufactured primary mirror truss, factory manufactured geodesic enclosure dome, air bearing rotation of primary mirror, tracker, and dome systems directly on concrete piers, and tracking via a hexapod system. Current estimates put the cost of the ELT at $200 million for a 25-meter aperture utilizing a 33-meter primary mirror array. Construction of the ELT would provide the astronomy community with an optical telescope nearly an order of magnitude larger than even the largest telescopes in operation or under construction today.

  2. Correlation between positron emission tomography and Cerenkov luminescence imaging in vivo and ex vivo using 64Cu-labeled antibodies in a neuroblastoma mouse model

    PubMed Central

    Maier, Florian C.; Schmitt, Julia; Maurer, Andreas; Ehrlichmann, Walter; Reischl, Gerald; Nikolaou, Konstantin; Handgretinger, Rupert; Pichler, Bernd J.; Thaiss, Wolfgang M.

    2016-01-01

    Antibody-based therapies gain momentum in clinical therapy, thus the need for accurate imaging modalities with respect to target identification and therapy monitoring are of increasing relevance. Cerenkov luminescence imaging (CLI) are a novel method detecting charged particles emitted during radioactive decay with optical imaging. Here, we compare Position Emission Tomography (PET) with CLI in a multimodal imaging study aiming at the fast and efficient screening of monoclonal antibodies (mAb) designated for targeting of the neuroblastoma-characteristic epitope disialoganglioside GD2. Neuroblastoma-bearing SHO mice were injected with a 64Cu-labeled GD2-specific mAb. The tumor uptake was imaged 3 h, 24 h and 48 h after tracer injection with both, PET and CLI, and was compared to the accumulation in GD2-negative control tumors (human embryonic kidney, HEK-293). In addition to an in vivo PET/CLI-correlation over time, we also demonstrate linear correlations of CLI- and γ-counter-based biodistribution analysis. CLI with its comparably short acquisition time can thus be used as an attractive one-stop-shop modality for the longitudinal monitoring of antibody-based tumor targeting and ex vivo biodistribution. These findings suggest CLI as a reliable alternative for PET and biodistribution studies with respect to fast and high-throughput screenings in subcutaneous tumors traced with radiolabeled antibodies. However, in contrast to PET, CLI is not limited to positron-emitting isotopes and can therefore also be used for the visualization of mAb labeled with therapeutic isotopes like electron emitters. PMID:27602580

  3. Combined Cerenkov luminescence and nuclear imaging of radioiodine in the thyroid gland and thyroid cancer cells expressing sodium iodide symporter: initial feasibility study.

    PubMed

    Jeong, Shin Young; Hwang, Mi-Hye; Kim, Jung Eun; Kang, Sungmin; Park, Jeong Chan; Yoo, Jeongsoo; Ha, Jeoung-Hee; Lee, Sang-Woo; Ahn, Byeong-Cheol; Lee, Jaetae

    2011-01-01

    Radioiodine (RI) such as (131)I or (124)I, can generate luminescent emission and be detected with an optical imaging (OI) device. To evaluate the possibility of a novel Cerenkov luminescence imaging (CLI) for application in thyroid research, we performed feasibility studies of CLI by RI in the thyroid gland and human anaplastic thyroid carcinoma cells expressing sodium iodide symporter gene (ARO-NIS). For in vitro study, FRTL-5 and ARO-NIS were incubated with RI, and the luminometric and CLI intensity was measured with luminometer and OI device. Luminescence intensity was compared with the radioactivity measured with γ-counter. In vivo CLI of the thyroid gland was performed in mice after intravenous injection of RI with and without thyroid blocking. Mice were implanted with ARO-NIS subcutaneously, and CLI was performed with injection of (124)I. Small animal PET or γ-camera imaging was also performed. CLI intensities of thyroid gland and ARO-NIS were quantified, and compared with the radioactivities measured from nuclear images (NI). Luminometric assay and OI confirmed RI uptake in the cells in a dose-dependent manner, and luminescence intensity was well correlated with radioactivity of the cells. CLI clearly demonstrated RI uptake in thyroid gland and xenografted ARO-NIS cells in mice, which was further confirmed by NI. A strong positive correlation was observed between CLI intensity and radioactivity assessed by NI. We successfully demonstrated dual molecular imaging of CLI and NI using RI both in vitro and in vivo. CLI can provide a new OI strategy in preclinical thyroid studies.

  4. Preliminary research on overmoded high-power millimeter-wave Cerenkov generator with dual-cavity reflector in low guiding magnetic field

    SciTech Connect

    Ye, Hu; Wu, Ping; Chen, Changhua; Ning, Hui; Tan, Weibing; Teng, Yan; Shi, Yanchao; Song, Zhimin; Cao, Yibing; Du, Zhaoyu

    2015-12-15

    This paper presents preliminary research on a V-band overmoded Cerenkov generator with dual-cavity reflector operating in a low guiding magnetic field. It is found that the fluctuation of the electron envelope in the low guiding magnetic field can be predicted using an equivalent coaxial model of a foilless diode, and a dual-cavity reflector based on the model matching method can provide strong reflection at the front end of the overmoded structures so that any microwave power that leaks into the diode region can be effectively suppressed. Numerical simulations indicate that the control of the beam envelope and the use of the dual-cavity reflector ease generator operation in the low guiding magnetic field. In the experimental research, the fluctuation of the annular electron beam with the outer radius of 7.5 mm measures approximately 0.7 mm, which is in good agreement with the theoretical results. The disturbance caused by power leaking from the overmoded slow wave structure is eliminated by the dual-cavity reflector. With accurate fabrication and assembly processes, an operating frequency of 61.6 GHz is attained by the fifth harmonic heterodyne method, and the output power is measured to be approximately 123 MW by the far-field measurement method at a diode voltage of 445 kV, a beam current of 4.45 kA, and under a guiding magnetic field of 1.45 T. The output mode is measured using an array of neon flash bulbs, and the pulse shortening phenomenon is both observed and analyzed.

  5. Wide-angle Optical Telescope for the EUSO Experiments

    NASA Technical Reports Server (NTRS)

    Hillman, L. W.; Takahaski, Y.; Zuccaro, A.; Lamb, D.; Pitalo, K.; Lopado, A.; Keys, A.

    2003-01-01

    Future spacebased air shower experiments, including the planned Extreme Universe Space Observatory (EUSO) mission, require a wide-angle telescope in the near-UV wavelengths 330 - 400 nm. Widest possible target aperture of earth's atmosphere, such as greater than 10(exp 5) square kilometers sr, can be viewed within the field-of-view of 30 degrees from space. EUSO's optical design is required to be compact, being constrained by the allocated mass and diameter for use in space. Two doublesided Fresnel lenses with 2.5-m diameter are chosen for the baseline design. It satisfies the imaging resolution of 0.1 degree over the 30-degree field of view.

  6. Large aperture diffractive space telescope

    DOEpatents

    Hyde, Roderick A.

    2001-01-01

    A large (10's of meters) aperture space telescope including two separate spacecraft--an optical primary objective lens functioning as a magnifying glass and an optical secondary functioning as an eyepiece. The spacecraft are spaced up to several kilometers apart with the eyepiece directly behind the magnifying glass "aiming" at an intended target with their relative orientation determining the optical axis of the telescope and hence the targets being observed. The objective lens includes a very large-aperture, very-thin-membrane, diffractive lens, e.g., a Fresnel lens, which intercepts incoming light over its full aperture and focuses it towards the eyepiece. The eyepiece has a much smaller, meter-scale aperture and is designed to move along the focal surface of the objective lens, gathering up the incoming light and converting it to high quality images. The positions of the two space craft are controlled both to maintain a good optical focus and to point at desired targets which may be either earth bound or celestial.

  7. TMT telescope structure thermal model

    NASA Astrophysics Data System (ADS)

    Vogiatzis, Konstantinos; Sadjadpour, Amir; Roberts, Scott

    2014-08-01

    The thermal behavior of the Thirty Meter Telescope (TMT) Telescope Structure (STR) and the STR mounted subsystems depends on the heat load of the System, the thermal properties of component materials and the environment as well as their interactions through convection, conduction and radiation. In this paper the thermal environment is described and the latest three-dimensional Computational Solid Dynamics (CSD) model is presented. The model tracks the diurnal temperature variation of the STR and the corresponding deformations. The resulting displacements are fed into the TMT Merit Function Routine (MFR), which converts them into translations and rotations of the optical surfaces. They, in turn, are multiplied by the TMT optical sensitivity matrix that delivers the corresponding pointing error. Thus the thermal performance of the structure can be assessed for requirement compliance, thermal drift correction strategies and look-up tables can be developed and design guidance can be provided. Results for a representative diurnal cycle based on measured temperature data from the TMT site on Mauna Kea and CFD simulations are presented and conclusions are drawn.

  8. Far Ultraviolot Space Telescope (FAUST)

    NASA Technical Reports Server (NTRS)

    Bowyer, S.

    1988-01-01

    The Far Ultraviolet Space Telescope is a compact, wide field-of-view, far ultraviolet instrument designed for observations of extended and point sources of astronomical interest. It was originally used in sounding rocket work by both French and American investigators. The instrument was modified for flight on the space shuttle and flew on the Spacelab 1 mission as a joint effort between the Laboratoire d'Astronomie Spatiale and the University of California, Berkeley. The prime experiment objective of this telescope on the Atmospheric Laboratory Applications and Science (ATLAS 1) NASA mission is to observe faint astronomical sources in the far ultraviolet with sensitivities far higher than previously available. The experiment will cover the 1300 to 1800 A band, which is inaccessible to observers on earth. The observing program during the mission consists of obtaining deep sky images during spacecraft nighttime. The targets will include hot stars and nebulae in our own galaxy, faint diffuse galactic features similar to the cirrus clouds seen by the Infrared Astronomical Satellite (IRAS), large nearby galaxies, nearby clusters of galaxies, and objects of cosmological interest such as quasars and the diffuse far ultraviolet background.

  9. Origins Space Telescope: Community Participation

    NASA Astrophysics Data System (ADS)

    Carey, Sean J.; Origins Space Telescope Study Team

    2017-01-01

    The Origins Space Telescope (OST) is the mission concept for the Far-Infrared Surveyor, a study in development by NASA in preparation for the 2020 Astronomy and Astrophysics Decadal Survey. Origins is planned to be a large aperture, actively-cooled telescope covering a wide span of the mid- to far-infrared spectrum. Its imagers and spectrographs will enable a variety of surveys of the sky that will discover and characterize the most distant galaxies, Milky-Way, exoplanets, and the outer reaches of our Solar system. Origins will enable flagship-quality general observing programs led by the astronomical community in the 2030s. This poster will outline the ways in which the astronomical community can participate in the STDT activities and a summary of tools that are currently available or are planned for the community during the study. The Science and Technology Definition Team (STDT) would like to hear your science needs and ideas for this mission. The team can be contacted at firsurveyor_info@lists.ipac.caltech.edu.

  10. Space Telescopes and Orbital Debris

    NASA Astrophysics Data System (ADS)

    Seitzer, Patrick

    2009-01-01

    Almost 12,000 artificial objects orbiting the Earth are currently in the public catalog of orbital elements maintained by the USAF. Only a small fraction of them are operational satellites. The remainder is satellites whose missions have ended, rocket bodies, and parts and debris from larger parent objects. And the catalog only contains the biggest and brightest of the objects in orbit. The Low Earth Orbit (LEO) regime where most of this population concentrates is also a regime of incredible interest to astronomers, since it is where flagship missions such as the Hubble Space Telescope and other Great Observatories operate. I'll review the current state of knowledge of the orbital debris population, how it has grown with time, and how this environment could affect current and future space telescopes. There are mitigation measures which many spacecraft operators have adopted which can control the growth of the debris population. Orbital debris research at the University of Michigan is funded by NASA's Orbital Debris Program Office, Johnson Space Center, Houston, Texas.

  11. Mars Telescopic Observations Workshop II

    NASA Technical Reports Server (NTRS)

    Sprague, A. L. (Editor); Bell, J. F., III (Editor)

    1997-01-01

    Mars Telescopic Observations Workshop E convened in Tucson, Arizona, in October 1997 by popular demand slightly over two years following the first successful Mars Telescopic Observations Workshop, held in Ithaca, New York, in August 1995. Experts on Mars from the United Kingdom, Japan, Germany, and the United States were present. Twenty-eight oral presentations were made and generous time allotted for useful discussions among participants. The goals of the workshop were to (1) summarize active groundbased observing programs and evaluate them in the context of current and future space missions to Mars, (2) discuss new technologies and instrumentation in the context of changing emphasis of observations and theory useful for groundbased observing, and (3) more fully understand capabilities of current and planned Mars missions to better judge which groundbased observations are and will continue to be of importance to our overall Mars program. In addition, the exciting new discoveries presented from the Pathfinder experiments and the progress report from the Mars Global Surveyor infused the participants with satisfaction for the successes achieved in the early stages of these missions. Just as exciting was the enthusiasm for new groundbased programs designed to address new challenges resulting from mission science results. We would like to thank the National Aeronautics and Space Administration as well as Dr. David Black, director of the Lunar and Planetary Institute, and the staff of the Institute's Publications and Program Services Department for providing logistical, administrative, and publication support services for this workshop.

  12. Origins Space Telescope: Study Plan

    NASA Astrophysics Data System (ADS)

    Cooray, Asantha R.; Origins Space Telescope Study Team

    2017-01-01

    The Origins Space Telescope (OST) is the mission concept for the Far-Infrared Surveyor, a study in development by NASA in preparation for the 2020 Astronomy and Astrophysics Decadal Survey. Origins is planned to be a large aperture, actively-cooled telescope covering a wide span of the mid- to far-infrared spectrum. Its spectrographs will enable 3D surveys of the sky that will discover and characterize the most distant galaxies, Milky-Way, exoplanets, and the outer reaches of our Solar system. Origins will enable flagship-quality general observing programs led by the astronomical community in the 2030s. The Science and Technology Definition Team (STDT) would like to hear your science needs and ideas for this mission. The team can be contacted at firsurveyor_info@lists.ipac.caltech.edu. This presentation will provide a summary of the OST STDT, the OST Study Team based at NASA Goddard Space Flight Center, study partners, and the advisory panel to the study. This presentation will also summarize recent activities, including the process used to reach a decision on the mission architecture, the identification of key science drivers, and the key study milestones between 2017 and 2020.

  13. JWST Telescope Integration and Test Progress

    NASA Technical Reports Server (NTRS)

    Matthews, Gary W.; Whitman, Tony L.; Feinberg, Lee D.; Voyton, Mark F.; Lander, Juli A.; Keski-Kuha, Ritva

    2016-01-01

    The James Webb Space Telescope (JWST) is a 6.5m, segmented, IR telescope that will explore the first light of the universe after the big bang. The JWST Optical Telescope Element (Telescope) integration and test program is well underway. The telescope was completed in the spring of 2016 and the cryogenic test equipment has been through two optical test programs leading up to the final flight verification program. The details of the telescope mirror integration will be provided along with the current status of the flight observatory. In addition, the results of the two optical ground support equipment cryo tests will be shown and how these plans fold into the flight verification program.

  14. JWST telescope integration and test progress

    NASA Astrophysics Data System (ADS)

    Matthews, Gary W.; Whitman, Tony L.; Feinberg, Lee D.; Voyton, Mark F.; Lander, Juli A.; Keski-Kuha, Ritva

    2016-07-01

    The James Webb Space Telescope (JWST) is a 6.5m, segmented, IR telescope that will explore the first light of the universe after the big bang. The JWST Optical Telescope Element (Telescope) integration and test program is well underway. The telescope was completed in the spring of 2016 and the cryogenic test equipment has been through two optical test programs leading up to the final flight verification program. The details of the telescope mirror integration will be provided along with the current status of the flight observatory. In addition, the results of the two optical ground support equipment cryo tests will be shown and how these plans fold into the flight verification program.

  15. JWST telescope integration and test status

    NASA Astrophysics Data System (ADS)

    Matthews, Gary; Scorse, Thomas; Kennard, Scott; Spina, John; Whitman, Tony; Texter, Scott; Atkinson, Charles; Young, Greg; Keski-Kuha, Ritva; Marsh, James; Lander, Juli; Feinberg, Lee

    2014-08-01

    The James Webb Space Telescope (JWST) is a 6.5m, segmented, IR telescope that will explore the first light of the universe after the big bang. 2014 is an incredible year for the Telescope Alignment, Integration, and Test portion of the program. Long awaited and planned, the two segment Pathfinder telescope will be built and the Optical Ground Support Equipment (OGSE) will be integrated into the large cryo-vacuum chamber at the Johnson Spaceflight Center. The current status of the integration equipment and the demonstrations leading up to the flight-like Pathfinder telescope will be provided as the first step to the final verification of the complex cryo test equipment. The plans and status of bringing the OGSE on-line and ready for a series of risk reduction cryo tests starting in 2015 on the Pathfinder Telescope will also be presented.

  16. Telescope Systems for Balloon-Borne Research

    NASA Technical Reports Server (NTRS)

    Swift, C. (Editor); Witteborn, F. C. (Editor); Shipley, A. (Editor)

    1974-01-01

    The proceedings of a conference on the use of balloons for scientific research are presented. The subjects discussed include the following: (1) astronomical observations with balloon-borne telescopes, (2) orientable, stabilized balloon-borne gondola for around-the-world flights, (3) ultraviolet stellar spectrophotometry from a balloon platform, (4) infrared telescope for balloon-borne infrared astronomy, and (5) stabilization, pointing, and command control of balloon-borne telescopes.

  17. Segmented Mirror Telescope Model and Simulation

    DTIC Science & Technology

    2011-06-01

    NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS SEGMENTED MIRROR TELESCOPE MODEL AND SIMULATION by Travis W. Axtell June 2011 Thesis Co...Mirror Telescope Model and Simulation Travis W. Axtell Naval Postgraduate School Monterey, CA 93943 Department of the Navy Approved for public release...Department of Defense or the U.S. Government. IRB Protocol Number: N/A The Segmented Mirror Telescope (SMT) housed at the Naval Postgraduate School is a

  18. ANTARES: The first undersea neutrino telescope

    NASA Astrophysics Data System (ADS)

    Ageron, M.; Aguilar, J. A.; Al Samarai, I.; Albert, A.; Ameli, F.; André, M.; Anghinolfi, M.; Anton, G.; Anvar, S.; Ardid, M.; Arnaud, K.; Aslanides, E.; Assis Jesus, A. C.; Astraatmadja, T.; Aubert, J.-J.; Auer, R.; Barbarito, E.; Baret, B.; Basa, S.; Bazzotti, M.; Becherini, Y.; Beltramelli, J.; Bersani, A.; Bertin, V.; Beurthey, S.; Biagi, S.; Bigongiari, C.; Billault, M.; Blaes, R.; Bogazzi, C.; de Botton, N.; Bou-Cabo, M.; Boudahef, B.; Bouwhuis, M. C.; Brown, A. M.; Brunner, J.; Busto, J.; Caillat, L.; Calzas, A.; Camarena, F.; Capone, A.; Caponetto, L.; Cârloganu, C.; Carminati, G.; Carmona, E.; Carr, J.; Carton, P. H.; Cassano, B.; Castorina, E.; Cecchini, S.; Ceres, A.; Chaleil, Th.; Charvis, Ph.; Chauchot, P.; Chiarusi, T.; Circella, M.; Compère, C.; Coniglione, R.; Coppolani, X.; Cosquer, A.; Costantini, H.; Cottini, N.; Coyle, P.; Cuneo, S.; Curtil, C.; D'Amato, C.; Damy, G.; van Dantzig, R.; de Bonis, G.; Decock, G.; Decowski, M. P.; Dekeyser, I.; Delagnes, E.; Desages-Ardellier, F.; Deschamps, A.; Destelle, J.-J.; di Maria, F.; Dinkespiler, B.; Distefano, C.; Dominique, J.-L.; Donzaud, C.; Dornic, D.; Dorosti, Q.; Drogou, J.-F.; Drouhin, D.; Druillole, F.; Durand, D.; Durand, R.; Eberl, T.; Emanuele, U.; Engelen, J. J.; Ernenwein, J.-P.; Escoffier, S.; Falchini, E.; Favard, S.; Fehr, F.; Feinstein, F.; Ferri, M.; Ferry, S.; Fiorello, C.; Flaminio, V.; Folger, F.; Fritsch, U.; Fuda, J.-L.; Galatá, S.; Galeotti, S.; Gay, P.; Gensolen, F.; Giacomelli, G.; Gojak, C.; Gómez-González, J. P.; Goret, Ph.; Graf, K.; Guillard, G.; Halladjian, G.; Hallewell, G.; van Haren, H.; Hartmann, B.; Heijboer, A. J.; Heine, E.; Hello, Y.; Henry, S.; Hernández-Rey, J. J.; Herold, B.; Hößl, J.; Hogenbirk, J.; Hsu, C. C.; Hubbard, J. R.; Jaquet, M.; Jaspers, M.; de Jong, M.; Jourde, D.; Kadler, M.; Kalantar-Nayestanaki, N.; Kalekin, O.; Kappes, A.; Karg, T.; Karkar, S.; Karolak, M.; Katz, U.; Keller, P.; Kestener, P.; Kok, E.; Kok, H.; Kooijman, P.; Kopper, C.; Kouchner, A.; Kretschmer, W.; Kruijer, A.; Kuch, S.; Kulikovskiy, V.; Lachartre, D.; Lafoux, H.; Lagier, P.; Lahmann, R.; Lahonde-Hamdoun, C.; Lamare, P.; Lambard, G.; Languillat, J.-C.; Larosa, G.; Lavalle, J.; Le Guen, Y.; Le Provost, H.; Levansuu, A.; Lefèvre, D.; Legou, T.; Lelaizant, G.; Lévéque, C.; Lim, G.; Lo Presti, D.; Loehner, H.; Loucatos, S.; Louis, F.; Lucarelli, F.; Lyashuk, V.; Magnier, P.; Mangano, S.; Marcel, A.; Marcelin, M.; Margiotta, A.; Martinez-Mora, J. A.; Masullo, R.; Mazéas, F.; Mazure, A.; Meli, A.; Melissas, M.; Migneco, E.; Mongelli, M.; Montaruli, T.; Morganti, M.; Moscoso, L.; Motz, H.; Musumeci, M.; Naumann, C.; Naumann-Godo, M.; Neff, M.; Niess, V.; Nooren, G. J. L.; Oberski, J. E. J.; Olivetto, C.; Palanque-Delabrouille, N.; Palioselitis, D.; Papaleo, R.; Păvălaş, G. E.; Payet, K.; Payre, P.; Peek, H.; Petrovic, J.; Piattelli, P.; Picot-Clemente, N.; Picq, C.; Piret, Y.; Poinsignon, J.; Popa, V.; Pradier, T.; Presani, E.; Prono, G.; Racca, C.; Raia, G.; van Randwijk, J.; Real, D.; Reed, C.; Réthoré, F.; Rewiersma, P.; Riccobene, G.; Richardt, C.; Richter, R.; Ricol, J. S.; Rigaud, V.; Roca, V.; Roensch, K.; Rolin, J.-F.; Rostovtsev, A.; Rottura, A.; Roux, J.; Rujoiu, M.; Ruppi, M.; Russo, G. V.; Salesa, F.; Salomon, K.; Sapienza, P.; Schmitt, F.; Schöck, F.; Schuller, J.-P.; Schüssler, F.; Sciliberto, D.; Shanidze, R.; Shirokov, E.; Simeone, F.; Sottoriva, A.; Spies, A.; Spona, T.; Spurio, M.; Steijger, J. J. M.; Stolarczyk, Th.; Streeb, K.; Sulak, L.; Taiuti, M.; Tamburini, C.; Tao, C.; Tasca, L.; Terreni, G.; Tezier, D.; Toscano, S.; Urbano, F.; Valdy, P.; Vallage, B.; van Elewyck, V.; Vannoni, G.; Vecchi, M.; Venekamp, G.; Verlaat, B.; Vernin, P.; Virique, E.; de Vries, G.; van Wijk, R.; Wijnker, G.; Wobbe, G.; de Wolf, E.; Yakovenko, Y.; Yepes, H.; Zaborov, D.; Zaccone, H.; Zornoza, J. D.; Zúñiga, J.

    2011-11-01

    The ANTARES Neutrino Telescope was completed in May 2008 and is the first operational Neutrino Telescope in the Mediterranean Sea. The main purpose of the detector is to perform neutrino astronomy and the apparatus also offers facilities for marine and Earth sciences. This paper describes the design, the construction and the installation of the telescope in the deep sea, offshore from Toulon in France. An illustration of the detector performance is given.

  19. Laser Metrology Sensing and Control for Large Segmented-Mirror Telescopes

    NASA Technical Reports Server (NTRS)

    Zhao, Feng; Rao, Shanti; Ksendzov, Alex; Kadogawa, Hiroshi

    2006-01-01

    Described an optical hexapod metrology concept: a) Can work together with edge sensors; b) Can measure M1 - M2 distance and M1 global curvature. Swept-frequency laser metrology system: a) Absolute optical path length measurement (approx.1 micron); b) Relative optical path length measurement (approx.nm) Air turbulence is a concern for ground-based telescopes and needs further study.

  20. Preliminary Cost Model for Space Telescopes

    NASA Technical Reports Server (NTRS)

    Stahl, H. Philip; Prince, F. Andrew; Smart, Christian; Stephens, Kyle; Henrichs, Todd

    2009-01-01

    Parametric cost models are routinely used to plan missions, compare concepts and justify technology investments. However, great care is required. Some space telescope cost models, such as those based only on mass, lack sufficient detail to support such analysis and may lead to inaccurate conclusions. Similarly, using ground based telescope models which include the dome cost will also lead to inaccurate conclusions. This paper reviews current and historical models. Then, based on data from 22 different NASA space telescopes, this paper tests those models and presents preliminary analysis of single and multi-variable space telescope cost models.

  1. Robotic telescope observing with the BAA

    NASA Astrophysics Data System (ADS)

    Meadows, P.

    2010-06-01

    Have you ever wished you had access to a telescope that can image down to magnitude 20 from the comfort of your own home? This is now made possible by using the growing number of robotic telescopes around the world that are available for amateur astronomers to acquire such CCD imagery. In 2008, using income derived from the legacy of renowned BAA observer Harold Ridley, the Robotic Telescope Project was started to encourage members to contribute to the various BAA Observing Sections using robotic telescopes, by providing a 50% subsidy on commercial rates (up to a limit per member).

  2. The Dutch Open Telescope on La Palma

    NASA Astrophysics Data System (ADS)

    Rutten, R. J.; Bettonvil, F. C. M.; Hammerschlag, R. H.; Jägers, A. P. L.; Leenaarts, J.; Snik, F.; Sütterlin, P.; Tziotziou, K.; de Wijn, A. G.

    The Dutch Open Telescope (DOT) on La Palma is an innovative solar telescope combining open telescope structure and an open support tower with a multi-wavelength imaging assembly and with synchronous speckle cameras to generate high-resolution movies which sample different layers of the solar atmosphere simultaneously and co-spatially at high resolution over long durations. The DOT test and development phase is nearly concluded. The installation of an advanced speckle processor enables full science utilization including "Open-DOT" time allocation to the international community. Co-pointing with spectropolarimeters at other Canary Island telescopes and with TRACE furnishes valuable Solar-B precursor capabilities.

  3. A New 800 mm Automatic Telescope

    NASA Astrophysics Data System (ADS)

    Andrievsky, S. M.; Molotov, I. E.; Fashchevsky, N. N.; Podlesnyak, S. V.; Zhukov, V. V.; Kouprianov, V. V.; Kashuba, S. G.; Kashuba, V. I.; Mel'nichenko, V. F.; Gorbanev, Yu. M.

    A new automatic telescope, a 800-millimeter main mirror catadioptric anastigmatic aplanat, was constructed by specialists of Odessa National University Astronomical observatory (Ukraine) in cooperation with their colleagues from the ISON project (Russia), and was recently put into operation. The telescope is mounted at Mayaki station in suburb of Odessa. It is equipped with a focal corrector and a professional CCD camera. The telescope is used now for observations of geostationary objects, asteroids, and comets. In addition, this telescope can be used for the high precision photometric observations of faint objects up to 20m.

  4. European Extremely Large Telescope: progress report

    NASA Astrophysics Data System (ADS)

    Tamai, R.; Spyromilio, J.

    2014-07-01

    The European Extremely Large Telescope is a project of the European Southern Observatory to build and operate a 40-m class optical near-infrared telescope. The telescope design effort is largely concluded and construction contracts are being placed with industry and academic/research institutes for the various components. The siting of the telescope in Northern Chile close to the Paranal site allows for an integrated operation of the facility providing significant economies. The progress of the project in various areas is presented in this paper and references to other papers at this SPIE meeting are made.

  5. Design and construction of the Discovery Channel Telescope enclosure

    NASA Astrophysics Data System (ADS)

    Marshall, Heather K.; Teran, Jose U.; Bond, Kevin

    2010-07-01

    The Discovery Channel Telescope (DCT) is a project of Lowell Observatory, undertaken with support from Discovery Communications, Inc., to design and construct a 4-meter class telescope and support facility on a site approximately 40 miles southeast of Flagstaff, Arizona. The Discovery Channel Telescope Enclosure was completed in November, 2009. The DCT Enclosure is an octagonal steel structure with insulated composite panel skin. The structure rotates on sixteen compliant bogie assemblies attached to the stationary facility. The shutter is composed of two independently actuated, bi-parting structures that provide a viewing aperture. To improve seeing, the skin is covered with adhesive aluminum foil tape and the enclosed observing area is passively ventilated via rollup doors. The observing area can also be actively ventilated using a downdraft fan, and there are provisions for upgrades to active air conditioning. The enclosure also includes operational equipment such as a bridge crane, personnel lift, and access platforms. This paper discusses some of the design trades as well as the construction challenges and lessons learned by the DCT Project, its designer M3 Engineering and Technology Corporation (M3), and its general contractor, Building and Engineering Contractors, Southwest (BEC Southwest).

  6. Asteroid Detection Results Using the Space Surveillance Telescope

    NASA Astrophysics Data System (ADS)

    Ruprecht, Jessica D.; Ushomirsky, Gregory; Woods, Deborah F.; Viggh, Herbert E. M.; Varey, Jacob; Cornell, Mark E.; Stokes, Grant

    2015-11-01

    From 1998-2013, MIT Lincoln Laboratory operated a highly successful near-Earth asteroid search program using two 1-m optical telescopes located at the MIT Lincoln Laboratory Experimental Test Site (ETS) in Socorro, N.M. In 2014, the Lincoln Near-Earth Asteroid Research (LINEAR) program successfully transitioned operations from the two 1-m telescopes to the 3.5-m Space Surveillance Telescope (SST) located at Atom Site on White Sands Missile Range, N.M. This paper provides a summary of first-year performance and results for the LINEAR program with SST and provides an update on recent improvements to the moving-object pipeline architecture that increase utility of SST data for NEO discovery and improve sensitivity to fast-moving objects. Ruprecht et al. (2014) made predictions for SST NEO search productivity as a function of population model. This paper assesses the NEO search performance of SST in the first 1.5 years of operation and compares results to model predictions.This work is sponsored by the Defense Advanced Research Projects Agency and the National Aeronautics and Space Administration under Air Force Contract #FA8721-05-C-0002. The views, opinions, and/or findings contained in this article/presentation are those of the authors / presenters and should not be interpreted as representing the official views or policies of the Department of Defense or the U.S. Government. Distribution Statement A: Approved for public release, distribution unlimited.

  7. Asteroid Detection Results Using the Space Surveillance Telescope

    NASA Astrophysics Data System (ADS)

    Ruprecht, J.; Ushomirsky, G.; Woods, D.; Viggh, H.; Varey, J.; Cornell, M.; Stokes, G.

    From 1998-2013, MIT Lincoln Laboratory operated a highly successful near-Earth asteroid search program using two 1-m optical telescopes located at the MIT Lincoln Laboratory Experimental Test Site (ETS) in Socorro, N.M. In 2014, the Lincoln Near-Earth Asteroid Research (LINEAR) program successfully transitioned operations from the two 1-m telescopes to the 3.5-m Space Surveillance Telescope (SST) located at Atom Site on White Sands Missile Range, N.M. This paper provides a summary of first-year performance and results for the LINEAR program with SST and provides an update on recent improvements to the moving-object pipeline architecture that increase utility of SST data for NEO discovery and improve sensitivity to fast-moving objects. Ruprecht et al. (2014) made predictions for SST NEO search productivity as a function of population model. This paper assesses the NEO search performance of SST in the first 1.5 years of operation and compares results to model predictions. This work is sponsored by the Defense Advanced Research Projects Agency and the National Aeronautics and Space Administration under Air Force Contract #FA8721-05-C-0002. The views, opinions, and/or findings contained in this article/presentation are those of the authors / presenters and should not be interpreted as representing the official views or policies of the Department of Defense or the U.S. Government. Distribution Statement A: Approved for public release, distribution unlimited.

  8. Developing a Telescope Simulator Towards a Global Autonomous Robotic Telescope Network

    NASA Astrophysics Data System (ADS)

    Giakoumidis, N.; Ioannou, Z.; Dong, H.; Mavridis, N.

    2013-05-01

    A robotic telescope network is a system that integrates a number of telescopes to observe a variety of astronomical targets without being operated by a human. This system autonomously selects and observes targets in accordance to an optimized target. It dynamically allocates telescope resources depending on the observation requests, specifications of the telescopes, target visibility, meteorological conditions, daylight, location restrictions and availability and many other factors. In this paper, we introduce a telescope simulator, which can control a telescope to a desired position in order to observe a specific object. The system includes a Client Module, a Server Module, and a Dynamic Scheduler module. We make use and integrate a number of open source software to simulate the movement of a robotic telescope, the telescope characteristics, the observational data and weather conditions in order to test and optimize our system.

  9. The EEE Project: a sparse array of telescopes for the measurement of cosmic ray muons

    NASA Astrophysics Data System (ADS)

    La Rocca, P.; Abbrescia, M.; Avanzini, C.; Baldini, L.; Baldini Ferroli, R.; Batignani, G.; Bencivenni, G.; Bossini, E.; Chiavassa, A.; Cicalò, C.; Cifarelli, L.; Coccetti, F.; Coccia, E.; Corvaglia, A.; De Gruttola, D.; De Pasquale, S.; Di Giovanni, A.; D'Incecco, M.; Dreucci, M.; Fabbri, F. L.; Fattibene, E.; Ferraro, A.; Frolov, V.; Galeotti, P.; Garbini, M.; Gemme, G.; Gnesi, I.; Grazzi, S.; Gustavino, C.; Hatzifotiadou, D.; Liciulli, F.; Maggiora, A.; Maragoto Rodriguez, O.; Maron, G.; Martelli, B.; Mazziotta, M. N.; Miozzi, S.; Nania, R.; Noferini, F.; Nozzoli, F.; Panareo, M.; Panetta, M.; Paoletti, R.; Park, W.; Perasso, L.; Pilo, F.; Piragino, G.; Riggi, F.; Righini, G. C.; Rizzi, M.; Sartorelli, G.; Scapparone, E.; Schioppa, M.; Scribano, A.; Selvi, M.; Serci, S.; Siddi, E.; Squarcia, S.; Stori, L.; Taiuti, M.; Terreni, G.; Visnyei, O. B.; Vistoli, M. C.; Votano, L.; Williams, M. C. S.; Zani, S.; Zichichi, A.; Zuyeuski, R.

    2016-12-01

    The Extreme Energy Events (EEE) Project is meant to be the most extensive experiment to detect secondary cosmic particles in Italy. To this aim, more than 50 telescopes have been built at CERN and installed in high schools distributed all over the Italian territory. Each EEE telescope comprises three large area Multigap Resistive Plate Chambers (MRPCs) and is capable of reconstructing the trajectories of the charged particles traversing it with a good angular resolution. The excellent performance of the EEE telescopes allows a large variety of studies, from measuring the local muon flux in a single telescope, to detecting extensive air showers producing time correlations in the same metropolitan area, to searching for large-scale correlations between showers detected in telescopes tens, hundreds or thousands of kilometers apart. In addition to its scientific goal, the EEE Project also has an educational and outreach objective, its aim being to motivate young people by involving them directly in a real experiment. High school students and teachers are involved in the construction, testing and start-up of the EEE telescope in their school, then in its maintenance and data-acquisition, and later in the analysis of the data. During the last couple of years a great boost has been given to the EEE Project through the organization of simultaneous and centralized data taking with the whole telescope array. The raw data from all telescopes are transferred to CNAF (Bologna), where they are reconstructed and stored. The data are currently being analyzed, looking at various topics: variation of the rate of cosmic muons with time, upward going muons, muon lifetime, search for anisotropies in the muon angular distribution and for time coincidences between stations. In this paper an overall description of the experiment is given, including the design, construction and performance of the telescopes. The operation of the whole array is also presented by showing the most recent

  10. A versatile digital camera trigger for telescopes in the Cherenkov Telescope Array

    NASA Astrophysics Data System (ADS)

    Schwanke, U.; Shayduk, M.; Sulanke, K.-H.; Vorobiov, S.; Wischnewski, R.

    2015-05-01

    This paper describes the concept of an FPGA-based digital camera trigger for imaging atmospheric Cherenkov telescopes, developed for the future Cherenkov Telescope Array (CTA). The proposed camera trigger is designed to select images initiated by the Cherenkov emission of extended air showers from very-high energy (VHE, E > 20 GeV) photons and charged particles while suppressing signatures from background light. The trigger comprises three stages. A first stage employs programmable discriminators to digitize the signals arriving from the camera channels (pixels). At the second stage, a grid of low-cost FPGAs is used to process the digitized signals for camera regions with 37 pixels. At the third stage, trigger conditions found independently in any of the overlapping 37-pixel regions are combined into a global camera trigger by few central FPGAs. Trigger prototype boards based on Xilinx FPGAs have been designed, built and tested and were shown to function properly. Using these components a full camera trigger with a power consumption and price per channel of about 0.5 W and 19 €, respectively, can be built. With the described design the camera trigger algorithm can take advantage of pixel information in both the space and the time domain allowing, for example, the creation of triggers sensitive to the time-gradient of a shower image; the time information could also be exploited to online adjust the time window of the acquisition system for pixel data. Combining the results of the parallel execution of different trigger algorithms (optimized, for example, for the lowest and highest energies, respectively) on each FPGA can result in a better response over all photons energies (as demonstrated by Monte Carlo simulation in this work).

  11. SkyView Virtual Telescope:

    NASA Astrophysics Data System (ADS)

    McGlynn, Thomas A.; McDonald, Laura M.; Scollick, Keith A.

    2015-11-01

    The SkyView Virtual telescope provides access to survey datasets ranging from radio through the gamma-ray regimes. Over 100 survey datasets are currently available. The SkyView library referenced here is used as the basis for the SkyView web site (at http://skvyiew.gsfc.nasa.gov) but is designed for individual use by researchers as well. SkyView's approach to access surveys is distinct from most other toolkits. Rather than providing links to the original data, SkyView attempts to immediately re-render the source data in the user-requested reference frame, projection, scaling, orientation, etc. The library includes a set of geometry transformation and mosaicking tools that may be integrated into other applications independent of SkyView.

  12. Diffractive X-Ray Telescopes

    NASA Technical Reports Server (NTRS)

    Skinner, Gerald K.

    2010-01-01

    Diffractive X-ray telescopes, using zone plates, phase Fresnel lenses, or related optical elements have the potential to provide astronomers with true imaging capability with resolution many orders of magnitude better than available in any other waveband. Lenses that would be relatively easy to fabricate could have an angular resolution of the order of micro-arc-seconds or even better, that would allow, for example, imaging of the distorted spacetime in the immediate vicinity of the super-massive black holes in the center of active galaxies. What then is precluding their immediate adoption? Extremely long focal lengths, very limited bandwidth, and difficulty stabilizing the image are the main problems. The history, and status of the development of such lenses is reviewed here and the prospects for managing the challenges that they present are discussed.

  13. SLAC Cosmic Ray Telescope Facility

    SciTech Connect

    Va'vra, J.

    2010-02-15

    SLAC does not have a test beam for the HEP detector development at present. We have therefore created a cosmic ray telescope (CRT) facility, which is presently being used to test the FDIRC prototype. We have used it in the past to debug this prototype with the original SLAC electronics before going to the ESA test beam. Presently, it is used to test a new waveform digitizing electronics developed by the University of Hawaii, and we are also planning to incorporate the new Orsay TDC/ADC electronics. As a next step, we plan to put in a full size DIRC bar box with a new focusing optics, and test it together with a final SuberB electronics. The CRT is located in building 121 at SLAC. We anticipate more users to join in the future. This purpose of this note is to provide an introductory manual for newcomers.

  14. Adaptive Optics for Large Telescopes

    SciTech Connect

    Olivier, S

    2008-06-27

    The use of adaptive optics was originally conceived by astronomers seeking to correct the blurring of images made with large telescopes due to the effects of atmospheric turbulence. The basic idea is to use a device, a wave front corrector, to adjust the phase of light passing through an optical system, based on some measurement of the spatial variation of the phase transverse to the light propagation direction, using a wave front sensor. Although the original concept was intended for application to astronomical imaging, the technique can be more generally applied. For instance, adaptive optics systems have been used for several decades to correct for aberrations in high-power laser systems. At Lawrence Livermore National Laboratory (LLNL), the world's largest laser system, the National Ignition Facility, uses adaptive optics to correct for aberrations in each of the 192 beams, all of which must be precisely focused on a millimeter scale target in order to perform nuclear physics experiments.

  15. Compact telescope for free-space communications

    NASA Astrophysics Data System (ADS)

    Draganov, Vladimir; James, Daryl G.

    2002-10-01

    Several types of telescopes are used for free space telecommunications. The most common are Cassegrain and Gregorian telescopes. The main difference between Cassegrain and Gregorian optical systems is that Gregorian telescopes employ a concave secondary mirror located beyond the focus of the primary mirror. This results in longer tube lengths, as the distance between mirrors is slightly more than the sum of their focal lengths, which is the reason Cassegrain systems are the most common. In addition, Gregorian telescopes produce an upright image, while Cassegrain telescopes produce an inverted image. FSONA is presenting a new compact optical system, which can be described as a modified Gregorian telescope. This telescope is ideally suited for free space optical communications but also has many other applications. The compact telescope is created from a standard Gregorian system by flipping the secondary mirror over a folding mirror installed approximately in the middle of the optical path between primary and secondary mirrors. In this manner, the primary mirror is constructed with a concentric "double curved" geometry, and a central obscuring folding mirror which matches the diameter of the smaller curve of the primary is mounted a short distance in front. This "double curved" geometry is easily produced using diamond turning technology, and the result is a compact telescope approximately 1/2 the length of a regular Gregorian telescope and roughly 2/3 the length of a Cassegrain telescope. There are several advantages to using this type of telescope: 1. The system is very compact. Telescope can be as short as 1/7 of the focal length of the system. 2. For Cassegrain and Gregorian systems it is very critical to keep tight tolerances on the centration between primary and secondary mirrors. The modified Gregorian telescope will always have perfect centration because both curved surfaces are machined at the same time on a diamond turning lathe. The folding mirror is flat

  16. Advanced Technology Solar Telescope lower enclosure thermal system

    NASA Astrophysics Data System (ADS)

    Phelps, L.; Warner, M.

    2008-07-01

    The exterior of the Advanced Technology Solar Telescope enclosure requires cooling to eliminate so-called external dome seeing caused by solar loading during the observing day. This is achieved by way of coolant circulation through external plate coil panels, thereby maintaining the exterior surfaces of the enclosure at or just below ambient air temperature. As the distance from the optical path increases (e.g., on the surface of the lower enclosure), the stringency of the temperature requirement is diminished, thereby allowing a greater difference between the surface temperature and the ambient air temperature. This paper presents a comparison of the modeled performance of an active thermal control strategy on the lower enclosure to a passive strategy that employs concrete panels. A life-cycle cost analysis of each option is also presented.

  17. The Onsala Twin Telescope Project

    NASA Astrophysics Data System (ADS)

    Haas, R.

    2013-08-01

    This paper described the Onsala Twin Telescope project. The project aims at the construction of two new radio telescopes at the Onsala Space Observatory, following the VLBI2010 concept. The project starts in 2013 and is expected to be finalized within 4 years. Z% O. Rydbeck. Chalmers Tekniska Högskola, Göteborg, ISBN 91-7032-621-5, 407-823, 1991. B. Petrachenko, A. Niell, D. Behrend, B. Corey, J. Böhm, P. Charlot, A. Collioud, J. Gipson, R. Haas, Th. Hobiger, Y. Koyama, D. MacMillan, Z. Malkin, T. Nilsson, A. Pany, G. Tuccari, A. Whitney, and J. Wresnik. Design Aspects of the VLBI2010 System. NASA/TM-2009-214180, 58 pp., 2009. R. Haas, G. Elgered, J. Löfgren, T. Ning, and H.-G. Scherneck. Onsala Space Observatory - IVS Network Station. In K. D. Baver and D. Behrend, editors, International VLBI Service for Geodesy and Astrometry 2011 Annual Report, NASA/TP-2012-217505, 88-91, 2012. H.-G. Scherneck, G. Elgered, J. M. Johansson, and B. O. Rönnäng. Phys. Chem. Earth, Vol. 23, No. 7-8, 811-823, 1998. A. R. Whitney. Ph.D. thesis, Dept. of Electrical engineering, MIT Cambridge, MA., 1974. B. A. Harper, J. D. Kepert, and J. D. Ginger. Guidelines for converting between various wind averaging periods in tropical cyclone conditions. WMO/TD-No. 1555, 64 pp., 2010 (available at \\url{http://www.wmo.int/pages/prog/www/tcp/documents/WMO_TD_1555_en.pdf})

  18. Space Infrared Telescope Facility science instruments overview

    NASA Technical Reports Server (NTRS)

    Bothwell, Mary

    1991-01-01

    The Space Infrared Telescope Facility (SIRTF) will contain three cryogenically cooled infrared instruments: the Infrared Array Camera (IRAC), the Infrared Spectrograph (IRS), and the Multiband Infrared Photometer for SIRTF (MIPS). These instruments are sensitive to infrared radiation in the 1.8-1,200 micrometer range. This paper will discuss the three instruments' functional requirements and their accommodation in the SIRTF telescope system.

  19. The development of the Schmidt telescope

    NASA Astrophysics Data System (ADS)

    Wolfschmidt, G.

    2009-06-01

    % Bernhard Schmidt (1879-1935) was born in Estonia. After a few years of studying engineering he ran an optical workshop in Mittweida, Saxonia, between 1901 and 1927. Astronomers appreciated the quality of his telescopes. Starting in 1925, on behalf of the Hamburg Observatory, he developed a short focal length optical system with a large field of view. For this purpose, Schmidt moved his workshop to the observatory. He succeeded in inventing the ``Schmidt telescope'' which allows the imaging of a large field of the sky without any distortions. Schmidt's first telescope (spherical mirror diameter 0.44 m, correction plate 0.36 m diameter, aperture ratio 1:1.75, and focal length 0.625 m) has been used since 1962 at the Boyden Observatory in Bloemfontein/South Africa. Apart from his 0.36 m telescope, Schmidt produced a second larger one of 0.60 m aperture. Shortly after Schmidt's death, the director of the observatory published details on the invention and production of the Schmidt telescope. After World War II, Schmidt telescopes have been widely used. The first large Schmidt telescope, the ``Big Schmidt'' (1.26 m), Mount Palomar, USA, was completed in 1948. The 0.80 m Schmidt telescope of Hamburg Observatory, planned since 1936, finished in 1954, is now on Calar Alto/Spain.

  20. Proposed Integrated Radio-Telescope Network

    NASA Technical Reports Server (NTRS)

    Cohen, M. H.; Ewing, M. S.; Levy, G. S.; Mallis, R. K.; Readhead, A. C. S.; Smith, J. R.; Backer, D. C.

    1982-01-01

    Proposed network of radio telescopes, controlled by a central computer and managed by a single organization, offer potential for research on a scale that could not be matched by present privately and publicly-owned radio telescopes. With 10 antenna sites, network would establish base lines thousands of miles long. Antennas will be linked to computer center by telephone circuits.

  1. A Mechanical Analogue of the Refracting Telescope

    ERIC Educational Resources Information Center

    Vannoni, Maurizio; Molesini, Giuseppe; Sordini, Andrea; Straulino, Samuele

    2011-01-01

    The recent celebration of the discoveries made by Galileo four centuries ago has attracted new attention to the refracting telescope and to its use as an instrument for the observation of the night sky. This has offered the opportunity for addressing in the classroom the basic principles explaining the operation of the telescope. When doing so, a…

  2. Longer-baseline telescopes using quantum repeaters.

    PubMed

    Gottesman, Daniel; Jennewein, Thomas; Croke, Sarah

    2012-08-17

    We present an approach to building interferometric telescopes using ideas of quantum information. Current optical interferometers have limited baseline lengths, and thus limited resolution, because of noise and loss of signal due to the transmission of photons between the telescopes. The technology of quantum repeaters has the potential to eliminate this limit, allowing in principle interferometers with arbitrarily long baselines.

  3. Air Pollution

    MedlinePlus

    Air pollution is a mixture of solid particles and gases in the air. Car emissions, chemicals from factories, ... Ozone, a gas, is a major part of air pollution in cities. When ozone forms air pollution, it's ...

  4. The Status and Recent Results of the Telescope Array Experiment

    NASA Astrophysics Data System (ADS)

    Yamazaki, Katsuya

    The Telescope Array (TA) is a cosmic ray observatory of the largest aperture in the northern hemisphere, located in a desert in the western part of Utah, U.S.A., to explore the origin of ultrahigh energy cosmic rays, photons, and neutrinos. The TA employs two types of detectors to observe air showers generated by cosmic rays in the atmosphere: the first is a "surface detector (SD)" of scintillation counters to measure shower particles on the ground, and the second is a "fluorescence detector (FD)" of telescopes installed in three stations to observe fluorescence light, caused by air shower particles, from the atmosphere above the SD array. The TA detectors have been in routine operation since May 2008. We measured the energy spectrum of cosmic rays with energy greater than 1018 eV from our first 4-year data. We found a clear suppression of comic ray intensity above 5 × 1019 eV. This feature is consistent with a theoretical prediction that cosmic rays lose energies due to interaction with cosmic microwave background photons during propagation in the intergalactic space. In this talk, We will present the status of the TA experiment and the recent results, including the energy spectrum, study of the primary mass composition, and searches for anisotropies in the arrival directions. We also briefly describe plans for further extensions.

  5. Southern Fireworks above ESO Telescopes

    NASA Astrophysics Data System (ADS)

    1999-05-01

    New Insights from Observations of Mysterious Gamma-Ray Burst International teams of astronomers are now busy working on new and exciting data obtained during the last week with telescopes at the European Southern Observatory (ESO). Their object of study is the remnant of a mysterious cosmic explosion far out in space, first detected as a gigantic outburst of gamma rays on May 10. Gamma-Ray Bursters (GRBs) are brief flashes of very energetic radiation - they represent by far the most powerful type of explosion known in the Universe and their afterglow in optical light can be 10 million times brighter than the brightest supernovae [1]. The May 10 event ranks among the brightest one hundred of the over 2500 GRB's detected in the last decade. The new observations include detailed images and spectra from the VLT 8.2-m ANTU (UT1) telescope at Paranal, obtained at short notice during a special Target of Opportunity programme. This happened just over one month after that powerful telescope entered into regular service and demonstrates its great potential for exciting science. In particular, in an observational first, the VLT measured linear polarization of the light from the optical counterpart, indicating for the first time that synchrotron radiation is involved . It also determined a staggering distance of more than 7,000 million light-years to this GRB . The astronomers are optimistic that the extensive observations will help them to better understand the true nature of such a dramatic event and thus to bring them nearer to the solution of one of the greatest riddles of modern astrophysics. A prime example of international collaboration The present story is about important new results at the front-line of current research. At the same time, it is also a fine illustration of a successful collaboration among several international teams of astronomers and the very effective way modern science functions. It began on May 10, at 08:49 hrs Universal Time (UT), when the Burst

  6. Remote secure observing for the Faulkes Telescopes

    NASA Astrophysics Data System (ADS)

    Smith, Robert J.; Steele, Iain A.; Marchant, Jonathan M.; Fraser, Stephen N.; Mucke-Herzberg, Dorothea

    2004-09-01

    Since the Faulkes Telescopes are to be used by a wide variety of audiences, both powerful engineering level and simple graphical interfaces exist giving complete remote and robotic control of the telescope over the internet. Security is extremely important to protect the health of both humans and equipment. Data integrity must also be carefully guarded for images being delivered directly into the classroom. The adopted network architecture is described along with the variety of security and intrusion detection software. We use a combination of SSL, proxies, IPSec, and both Linux iptables and Cisco IOS firewalls to ensure only authenticated and safe commands are sent to the telescopes. With an eye to a possible future global network of robotic telescopes, the system implemented is capable of scaling linearly to any moderate (of order ten) number of telescopes.

  7. Monitoring LMXBs with the Faulkes Telescope

    NASA Astrophysics Data System (ADS)

    Lewis, Fraser; Russell, D. M.; Fender, R. P.; Roche, P.

    The Faulkes Telescope Project is the educational arm of the Las Cumbres Observatory Global Telescope Network (LCOGT). It currently has two 2-metre robotic telescopes, located at Haleakala on Maui (FT North) and Siding Spring in Australia (FT South). It is planned to increase this to six 2-metre telescopes in the future, complemented by a network of 30-40 smaller (0.4 - 1 metre) telescopes providing 24 hour coverage of both northern and southern hemispheres. We are undertaking a monitoring project of 10 low-mass X-ray binaries (LMXBs) using FT North to study the optical continuum behaviour of X-ray transients in quiescence. The introduction of FT South in September 2006 allows us to extend this monitoring to include 17 southern hemisphere LMXBs. With new instrumentation, we also intend to expand this monitoring to include both infrared wavelengths and spectroscopy.

  8. University of California ten meter telescope project

    NASA Astrophysics Data System (ADS)

    Nelson, J. E.

    1982-10-01

    A discussion is presented of the prospective design features of the segmented, 10-m diameter optical-IR range telescope which the University of California is planning to build on Mauna Kea, Hawaii, with attention to the performance levels obtained from prototypes. The telescope primary mirror will be formed by 36 actively controlled mirror segments, which will be polished to their desired shape by stressed mirror polishing. The active control system employs displacement sensors at the edges of the mirror segments to determine their positions, which are then adjusted by three displacement actuators/segment. The telescope overall design is described as a Ritchley-Cretien f/1.75-f/15 system. The telescope's dome is highly compact, and rotates on a stationary building in the manner of conventional telescope domes.

  9. James Webb Space Telescope Project (JWST) Overview

    NASA Technical Reports Server (NTRS)

    Dutta, Mitra

    2008-01-01

    This presentation provides an overview of the James Webb Space Telescope (JWST) Project. The JWST is an infrared telescope designed to collect data in the cosmic dark zone. Specifically, the mission of the JWST is to study the origin and evolution of galaxies, stars and planetary systems. It is a deployable telescope with a 6.5 m diameter, segmented, adjustable primary mirror. outfitted with cryogenic temperature telescope and instruments for infrared performance. The JWST is several times more sensitive than previous telescope and other photographic and electronic detection methods. It hosts a near infrared camera, near infrared spectrometer, mid-infrared instrument and a fine guidance sensor. The JWST mission objection and architecture, integrated science payload, instrument overview, and operational orbit are described.

  10. The Hexa-Pod-Telescope (HPT).

    NASA Astrophysics Data System (ADS)

    Schnur, G. F. O.; Stenvers, K.-H.; Pausch, K.

    The recently completed Hexa-Pod-Telescope (HPT) presents revolutionary new ideas on astronomical telescope design. Six mechanical struts support the HPT. The length of the six struts can be varied to permit the pointing and tracking of the HPT. Supporting the optical structure of the HPT from below allows to avoid superfluous balancing weights of normal telescopes. Compared to a classical telescope of the same mirror diameter the HPT realizes a weight reduction by a factor of 15! The HPT's primary mirror is realized as a hybrid structure consisting of a light-weight Carbon-Fibre-Reinforced Plastic (CFRP) structure permanently fixed to a 55 mm thin Zerodur faceplate, that forms the reflecting surface. Piezoelectrical ceramic positioners serve as active interface between the CFRP-structure and the optical surface. The low weight and extremely good optical quality of the HPT makes it an ideal candidate for larger telescopes in space, the moon and the stratosphere.

  11. Eyeglass. 1. Very large aperture diffractive telescopes.

    PubMed

    Hyde, R A

    1999-07-01

    The Eyeglass is a very large aperture (25-100-m) space telescope consisting of two distinct spacecraft, separated in space by several kilometers. A diffractive lens provides the telescope s large aperture, and a separate, much smaller, space telescope serves as its mobile eyepiece. Use of a transmissive diffractive lens solves two basic problems associated with very large aperture space telescopes; it is inherently launchable (lightweight, packagable, and deployable) it and virtually eliminates the traditional, very tight surface shape tolerances faced by reflecting apertures. The potential drawback to use of a diffractive primary (very narrow spectral bandwidth) is eliminated by corrective optics in the telescope s eyepiece; the Eyeglass can provide diffraction-limited imaging with either single-band (Deltalambda/lambda approximately 0.1), multiband, or continuous spectral coverage.

  12. Eyeglass. 1. Very large aperture diffractive telescopes

    SciTech Connect

    Hyde, R.A.

    1999-07-01

    The Eyeglass is a very large aperture (25{endash}100-m) space telescope consisting of two distinct spacecraft, separated in space by several kilometers. A diffractive lens provides the telescope{close_quote}s large aperture, and a separate, much smaller, space telescope serves as its mobile eyepiece. Use of a transmissive diffractive lens solves two basic problems associated with very large aperture space telescopes; it is inherently launchable (lightweight, packagable, and deployable) it and virtually eliminates the traditional, very tight surface shape tolerances faced by reflecting apertures. The potential drawback to use of a diffractive primary (very narrow spectral bandwidth) is eliminated by corrective optics in the telescope{close_quote}s eyepiece; the Eyeglass can provide diffraction-limited imaging with either single-band ({Delta}{lambda}/{lambda}{approximately}0.1), multiband, or continuous spectral coverage. {copyright} 1999 Optical Society of America

  13. A telescope with augmented reality functions

    NASA Astrophysics Data System (ADS)

    Hou, Qichao; Cheng, Dewen; Wang, Qiwei; Wang, Yongtian

    2016-10-01

    This study introduces a telescope with virtual reality (VR) and augmented reality (AR) functions. In this telescope, information on the micro-display screen is integrated to the reticule of telescope through a beam splitter and is then received by the observer. The design and analysis of telescope optical system with AR and VR ability is accomplished and the opto-mechanical structure is designed. Finally, a proof-of-concept prototype is fabricated and demonstrated. The telescope has an exit pupil diameter of 6 mm at an eye relief of 19 mm, 6° field of view, 5 to 8 times visual magnification , and a 30° field of view of the virtual image.

  14. VLTI First Fringes with Two Auxiliary Telescopes at Paranal

    NASA Astrophysics Data System (ADS)

    2005-03-01

    [Preview - JPEG: 537 x 400 pix - 31k] [Normal - JPEG: 1074 x 800 pix - 555k] [HiRes - JPEG: 3000 x 2235 pix - 6.0M] ESO PR Photo 07d/05 ESO PR Photo 07d/05 [Preview - JPEG: 400 x 550 pix - 60k] [Normal - JPEG: 800 x 1099 pix - 946k] [HiRes - JPEG: 2414 x 3316 pix - 11.0M] Captions: ESO PR Photo 07b/05 shows VLTI Auxiliary Telescopes 1 and 2 (AT1 and AT2) in the early evening light, with the spherical domes opened and ready for observations. In ESO PR Photo 07c/05, the same scene is repeated later in the evening, with three of the large telescope enclosures in the background. This photo and ESO PR Photo 07c/05 which is a time-exposure with AT1 and AT2 under the beautiful night sky with the southern Milky Way band were obtained by ESO staff member Frédéric Gomté. However, most of the time the large telescopes are used for other research purposes. They are therefore only available for interferometric observations during a limited number of nights every year. Thus, in order to exploit the VLTI each night and to achieve the full potential of this unique setup, some other (smaller), dedicated telescopes were included into the overall VLT concept. These telescopes, known as the VLTI Auxiliary Telescopes (ATs), are mounted on tracks and can be placed at precisely defined "parking" observing positions on the observatory platform. From these positions, their light beams are fed into the same common focal point via a complex system of reflecting mirrors mounted in an underground system of tunnels. The Auxiliary Telescopes are real technological jewels. They are placed in ultra-compact enclosures, complete with all necessary electronics, an air conditioning system and cooling liquid for thermal control, compressed air for enclosure seals, a hydraulic plant for opening the dome shells, etc. Each AT is also fitted with a transporter that lifts the telescope and relocates it from one station to another. It moves around with its own housing on the top of Paranal, almost like a snail

  15. High-precision robotic equatorial C-ring telescope mounts: design, fabrication, and performance

    NASA Astrophysics Data System (ADS)

    Dubberley, Matthew A.

    2010-07-01

    The performance of the C-ring telescope mount rivals other designs in stiffness, tracking, simplicity, lack of field rotation, mechanical size and operating envelope. Issues relating to cost, fabrication, and complexity have suppressed the prevalence of the C-ring mount. The Las Cumbres Observatory Global Telescope (LCOGT) robotic C-ring telescope mounts, built for its network of 1.0m and 0.4m telescopes, solve many of these issues. The design yields a scalable mount with performance capabilities well suited for telescopes located at the best astronomical sites in the world at a low cost. Pointing has been demonstrated to be under 7 arc-sec RMS. Unguided tracking performance is 0.6 arc-sec for 1 minute and 2 arc-sec for 15 minutes. Slew speeds of 10deg/sec are reliably used with sub-second settling times. The mount coupled with the 1.0m telescope yields a well damped 16 Hz system. Axes are driven with zero backlash direct drive motors with a 0.01 arc-sec resolution. High system bandwidth yields superb disturbance rejection making it ideal for open air operation. Drive and bearings are maintenance free and feature a novel "bug cover" to seal them from wear and damage. Low costs are achieved with the drive/feedback configuration, structure design, and fabrication techniques, as well minimizing operating and maintenance.

  16. System Design and Implementation of the Virginia Tech Optical Satellite Tracking Telescope

    NASA Astrophysics Data System (ADS)

    Luciani, D.; Black, J.

    2016-09-01

    The Virginia Tech Optical Satellite Tracking Telescope (VTOST) aims to test the feasibility of a commercial off-the-shelf (COTS) designed tracking system for Space Situational Awareness (SSA) data contribution. A novel approach is considered, combining two COTS systems, a high-powered telescope, built for astronomy purposes, and a larger field of view (FOV) camera. Using only publicly available two-line element sets (TLEs), orbital propagation accuracy degrades quickly with time from epoch and is often not accurate enough to task a high-powered, small FOV telescope. Under this experimental approach, the larger FOV camera is used to acquire and track the resident space object (RSO) and provide a real-time pointing update to allow the high-powered telescope to track the RSO and provide possible resolved imagery. VTOST is designed as a remotely taskable sensor, based on current network architecture, capable of serving as a platform for further SSA studies, including unresolved and resolved imagery analysis, network tasking, and orbit determination. Initial design considerations are based on the latest Raven class and other COTS based telescope research, including research by the Air Force Research Lab (AFRL), ExoAnalytic Solutions, and other university level telescope projects. A holistic system design, including astronomy, image processing, and tracking methods, in a low-budget environment is considered. Method comparisons and results of the system design process are presented.

  17. Beyond the Hubble Space Telescope: Early Development of the Next Generation Space Telescope

    NASA Astrophysics Data System (ADS)

    Smith, Robert W.; Patrick McCray, W.

    In this paper we investigate the early history of what was at first called the Next Generation Space Telescope, later to be renamed the James Webb Space Telescope. We argue that the initial ideas for such a Next Generation Space Telescope were developed in the context of the planning for a successor to the Hubble Space Telescope. Much the most important group of astronomers and engineers examining such a successor was based at the Space Telescope Science Institute in Baltimore. By the late 1980s, they had fashioned concepts for a successor that would work in optical, ultraviolet and infrared wavelengths, concepts that would later be regarded as politically unrealistic given the costs associated with them. We also explore how the fortunes of the planned Next Generation Space Telescope were intimately linked to that of its "parent," the Hubble Space Telescope.

  18. The Central Trigger System of the H.E.S.S. Telescope Array

    SciTech Connect

    Funk, S.; Hinton, J.; Hermann, G.; Berge, D.; Bernloehr, K.; Hofmann, W.; Nayman, P.; Toussenel, F.; Vincent, P.

    2005-02-21

    The High Energy Stereoscopic System (H.E.S.S.) is a new system of large atmospheric Cherenkov telescopes for GeV/TeV {gamma}-ray astronomy. This paper describes the array level trigger system of H.E.S.S. The system trigger requires the simultaneous detection of air-showers by several telescopes at the hardware level. This requirement allows a suppression of background events which in turn leads to a lower system energy threshold for the detection of gamma-rays.

  19. Development of the NASA MCAT Auxiliary Telescope for Orbital Debris Research

    NASA Technical Reports Server (NTRS)

    Frith, James; Lederer, Susan; Cowardin, Heather; Buckalew, Brent; Hickson, Paul; Anz-Meador, Phillip

    2016-01-01

    The National Aeronautical and Space Administration (NASA) has recently deployed the Meter Class Autonomous Telescope (MCAT) to Ascension Island. MCAT will provide NASA with a dedicated optical sensor for observations of orbital debris with the goal of statistically sampling the orbital and photometric characteristics of the population from low Earth to Geosynchronous orbits. Additionally, a small auxiliary telescope, co-located with MCAT, is being deployed to augment its observations by providing near-simultaneous photometry and astrometry, as well as offloading low priority targets from MCAT's observing queue. It will also be available to provide observational measurements to the Space Surveillance Network for the United States Air Force.

  20. Infrastructure for large space telescopes

    NASA Astrophysics Data System (ADS)

    MacEwen, Howard A.; Lillie, Charles F.

    2016-10-01

    It is generally recognized (e.g., in the National Aeronautics and Space Administration response to recent congressional appropriations) that future space observatories must be serviceable, even if they are orbiting in deep space (e.g., around the Sun-Earth libration point, SEL2). On the basis of this legislation, we believe that budgetary considerations throughout the foreseeable future will require that large, long-lived astrophysics missions must be designed as evolvable semipermanent observatories that will be serviced using an operational, in-space infrastructure. We believe that the development of this infrastructure will include the design and development of a small to mid-sized servicing vehicle (MiniServ) as a key element of an affordable infrastructure for in-space assembly and servicing of future space vehicles. This can be accomplished by the adaptation of technology developed over the past half-century into a vehicle approximately the size of the ascent stage of the Apollo Lunar Module to provide some of the servicing capabilities that will be needed by very large telescopes located in deep space in the near future (2020s and 2030s). We specifically address the need for a detailed study of these servicing requirements and the current proposals for using presently available technologies to provide the appropriate infrastructure.