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Sample records for multi-pixel photon counters

  1. Characterization and simulation of the response of Multi-Pixel Photon Counters to low light levels

    Energy Technology Data Exchange (ETDEWEB)

    Vacheret, A. [Department of Physics, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom); Barker, G.J. [Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL (United Kingdom); Dziewiecki, M. [Institute of Radioelectronics, Warsaw University of Technology, 15/19 Nowowiejska St., 00-665 Warsaw (Poland); Guzowski, P. [Department of Physics, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom); Haigh, M.D. [Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL (United Kingdom); Hartfiel, B. [Department of Physics and Astronomy, Louisiana State University, 202 Nicholson Hall, Tower Drive, Baton Rouge, LA 70803 (United States); Izmaylov, A. [Institute for Nuclear Research RAS, 60 October Revolution Pr. 7A, 117312 Moscow (Russian Federation); Johnston, W. [Department of Physics, Colorado State University, Fort Collins, CO 80523 (United States); Khabibullin, M.; Khotjantsev, A.; Kudenko, Yu. [Institute for Nuclear Research RAS, 60 October Revolution Pr. 7A, 117312 Moscow (Russian Federation); Kurjata, R. [Institute of Radioelectronics, Warsaw University of Technology, 15/19 Nowowiejska St., 00-665 Warsaw (Poland); Kutter, T. [Department of Physics and Astronomy, Louisiana State University, 202 Nicholson Hall, Tower Drive, Baton Rouge, LA 70803 (United States); Lindner, T. [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, Canada, BC V6T 1Z1 (Canada); Masliah, P. [Department of Physics, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom); Marzec, J. [Institute of Radioelectronics, Warsaw University of Technology, 15/19 Nowowiejska St., 00-665 Warsaw (Poland); Mineev, O.; Musienko, Yu. [Institute for Nuclear Research RAS, 60 October Revolution Pr. 7A, 117312 Moscow (Russian Federation); and others

    2011-11-11

    The calorimeter, range detector and active target elements of the T2K near detectors rely on the Hamamatsu Photonics Multi-Pixel Photon Counters (MPPCs) to detect scintillation light produced by charged particles. Detailed measurements of the MPPC gain, afterpulsing, crosstalk, dark noise, and photon detection efficiency for low light levels are reported. In order to account for the impact of the MPPC behavior on T2K physics observables, a simulation program has been developed based on these measurements. The simulation is used to predict the energy resolution of the detector.

  2. Characterization and simulation of the response of Multi-Pixel Photon Counters to low light levels

    International Nuclear Information System (INIS)

    Vacheret, A.; Barker, G.J.; Dziewiecki, M.; Guzowski, P.; Haigh, M.D.; Hartfiel, B.; Izmaylov, A.; Johnston, W.; Khabibullin, M.; Khotjantsev, A.; Kudenko, Yu.; Kurjata, R.; Kutter, T.; Lindner, T.; Masliah, P.; Marzec, J.; Mineev, O.; Musienko, Yu.

    2011-01-01

    The calorimeter, range detector and active target elements of the T2K near detectors rely on the Hamamatsu Photonics Multi-Pixel Photon Counters (MPPCs) to detect scintillation light produced by charged particles. Detailed measurements of the MPPC gain, afterpulsing, crosstalk, dark noise, and photon detection efficiency for low light levels are reported. In order to account for the impact of the MPPC behavior on T2K physics observables, a simulation program has been developed based on these measurements. The simulation is used to predict the energy resolution of the detector.

  3. Ultrafast photon number resolving detector with a temperature stabilized si multi pixel photon counter

    Energy Technology Data Exchange (ETDEWEB)

    Song, Minsoo; Hong, Eugene; Won, Eunil; Yoon, Tai Hyun [Korea Univ., Seoul (Korea, Republic of)

    2008-11-15

    Quantum information science has been rapidly progressed and matured and matured thanks to the recent developments of the single photon detection technologies. Single photon detectors such as a Si avalanche photo diode(APD)in the infrared, an InGaAs/InP APD in the telecommunication band, and a super conducting transient edge sensor(TES)in the broad region of the spectrum have been widely used. Single photon detectors, however, operating at the ultraviolet to visible (370nm∼800nm)regions has not been actively investigated partly due to the lack of single photon and/or entangled photon sources and the lack of solid state single photon detectors. In this paper, we investigate the single photon detection characteristics of a Si multi pixel photon counter(MPPC), which has a high spectral responsivity between 300nm to 800nm, as a photon number resolving solid state detector. Figure 1 shows the schematic diagram of the single photon detection set up at 399nm by using a temperature stabilized Si MPPC. The output beam of the laser being properly attenuated is directed to the MPPC module, at which fixed number of photo electrons corresponding to incident individual photon are generated at Geiger mode of the Si APD pixels. The detected photo current is converted into a digital signal by using a fast analog to digital converter and a digital oscilloscope stores the time sequence of the photo currents. Figure 2 shows the accumulated charges collected by MPPC at∼10.deg.C showing a clear single photon and two photons peaks, respectively, separated by ∼5 sigma of the coincidence counts at the two output ports of a Mach Zender interferometer as a function of optical path length difference. The research was supported by Seoul R and BD program(NT070127)and by the KRISS.

  4. Ultrafast photon number resolving detector with a temperature stabilized si multi pixel photon counter

    International Nuclear Information System (INIS)

    Song, Minsoo; Hong, Eugene; Won, Eunil; Yoon, Tai Hyun

    2008-01-01

    Quantum information science has been rapidly progressed and matured and matured thanks to the recent developments of the single photon detection technologies. Single photon detectors such as a Si avalanche photo diode(APD)in the infrared, an InGaAs/InP APD in the telecommunication band, and a super conducting transient edge sensor(TES)in the broad region of the spectrum have been widely used. Single photon detectors, however, operating at the ultraviolet to visible (370nm∼800nm)regions has not been actively investigated partly due to the lack of single photon and/or entangled photon sources and the lack of solid state single photon detectors. In this paper, we investigate the single photon detection characteristics of a Si multi pixel photon counter(MPPC), which has a high spectral responsivity between 300nm to 800nm, as a photon number resolving solid state detector. Figure 1 shows the schematic diagram of the single photon detection set up at 399nm by using a temperature stabilized Si MPPC. The output beam of the laser being properly attenuated is directed to the MPPC module, at which fixed number of photo electrons corresponding to incident individual photon are generated at Geiger mode of the Si APD pixels. The detected photo current is converted into a digital signal by using a fast analog to digital converter and a digital oscilloscope stores the time sequence of the photo currents. Figure 2 shows the accumulated charges collected by MPPC at∼10.deg.C showing a clear single photon and two photons peaks, respectively, separated by ∼5 sigma of the coincidence counts at the two output ports of a Mach Zender interferometer as a function of optical path length difference. The research was supported by Seoul R and BD program(NT070127)and by the KRISS

  5. Cryogenic readout for multiple VUV4 Multi-Pixel Photon Counters in liquid xenon

    Science.gov (United States)

    Di Giovanni, A.

    2018-03-01

    This work concerned the preliminary tests and characterization of a cryogenic preamplifier board for an array made of 16 S13370-3050CN (VUV4 family) Multi-Pixel Photon Counters manufactured by Hamamatsu and operated at liquid xenon temperature. The proposed prototype is based on the use of the Analog Devices AD8011 current feedback operational amplifier. The detector allows for single photon detection, making this device a promising choice for the future generation of neutrino and dark matter detectors based on liquid xenon targets.

  6. Cryogenic readout for multiple VUV4 Multi-Pixel Photon Counters in liquid xenon

    Science.gov (United States)

    Arneodo, F.; Benabderrahmane, M. L.; Bruno, G.; Conicella, V.; Di Giovanni, A.; Fawwaz, O.; Messina, M.; Candela, A.; Franchi, G.

    2018-06-01

    We present the performances and characterization of an array made of S13370-3050CN (VUV4 generation) Multi-Pixel Photon Counters manufactured by Hamamatsu and equipped with a low power consumption preamplifier operating at liquid xenon temperature (∼ 175 K). The electronics is designed for the readout of a matrix of maximum dimension of 8 × 8 individual photosensors and it is based on a single operational amplifier. The detector prototype presented in this paper utilizes the Analog Devices AD8011 current feedback operational amplifier, but other models can be used depending on the application. A biasing correction circuit has been implemented for the gain equalization of photosensors operating at different voltages. The results show single photon detection capability making this device a promising choice for future generation of large scale dark matter detectors based on liquid xenon, such as DARWIN.

  7. Advances in Multi-Pixel Photon Counter technology: First characterization results

    Energy Technology Data Exchange (ETDEWEB)

    Bonanno, G., E-mail: gbonanno@oact.inaf.it [INAF, Osservatorio Astrofisico di Catania, Via S. Sofia 78, I-95123 Catania (Italy); Marano, D.; Romeo, G.; Garozzo, S.; Grillo, A.; Timpanaro, M.C. [INAF, Osservatorio Astrofisico di Catania, Via S. Sofia 78, I-95123 Catania (Italy); Catalano, O.; Giarrusso, S.; Impiombato, D.; La Rosa, G.; Sottile, G. [INAF, Istituto di Astrofisica Spaziale e Fisica cosmica di Palermo, Via U. La Malfa 153, I-90146 Palermo Italy (Italy)

    2016-01-11

    Due to the recent advances in silicon photomultiplier technology, new types of Silicon Photomultiplier (SiPM), also named Multi-Pixel Photon Counter (MPPC) detectors have become recently available, demonstrating superior performance in terms of their most important electrical and optical parameters. This paper presents the latest characterization results of the novel Low Cross-Talk (LCT) MPPC families from Hamamatsu, where a noticeable fill-factor enhancement and cross-talk reduction is achieved. In addition, the newly adopted resin coating has been proven to yield improved photon detection capabilities in the 280–320 nm spectral range, making the new LCT MPPCs particularly suitable for emerging applications like Cherenkov Telescope Array, and Astroparticle Physics.

  8. Multi-Pixel Photon Counters for Optofluidic Characterization of Particles and Microalgae

    Directory of Open Access Journals (Sweden)

    Pouya Asrar

    2015-06-01

    Full Text Available We have developed an optofluidic biosensor to study microscale particles and different species of microalgae. The system is comprised of a microchannel with a set of chevron-shaped grooves. The chevrons allows for hydrodynamic focusing of the core stream in the center using a sheath fluid. The device is equipped with a new generation of highly sensitive photodetectors, multi-pixel photon counter (MPPC, with high gain values and an extremely small footprint. Two different sizes of high intensity fluorescent microspheres and three different species of algae (Chlamydomonas reinhardtii strain 21 gr, Chlamydomonas suppressor, and Chlorella sorokiniana were studied. The forward scattering emissions generated by samples passing through the interrogation region were carried through a multimode fiber, located in 135 degree with respect to the excitation fiber, and detected by a MPPC. The signal outputs obtained from each sample were collected using a data acquisition system and utilized for further statistical analysis. Larger particles or cells demonstrated larger peak height and width, and consequently larger peak area. The average signal output (integral of the peak for Chlamydomonas reinhardtii strain 21 gr, Chlamydomonas suppressor, and Chlorella sorokiniana falls between the values found for the 3.2 and 10.2 μm beads. Different types of algae were also successfully characterized.

  9. A sub-millimeter resolution PET detector module using a multi-pixel photon counter array

    International Nuclear Information System (INIS)

    Song, Tae Yong; Wu Heyu; Komarov, Sergey; Tai, Yuan-Chuan; Siegel, Stefan B

    2010-01-01

    A PET block detector module using an array of sub-millimeter lutetium oxyorthosilicate (LSO) crystals read out by an array of surface-mount, semiconductor photosensors has been developed. The detector consists of a LSO array, a custom acrylic light guide, a 3 x 3 multi-pixel photon counter (MPPC) array (S10362-11-050P, Hamamatsu Photonics, Japan) and a readout board with a charge division resistor network. The LSO array consists of 100 crystals, each measuring 0.8 x 0.8 x 3 mm 3 and arranged in 0.86 mm pitches. A Monte Carlo simulation was used to aid the design and fabrication of a custom light guide to control distribution of scintillation light over the surface of the MPPC array. The output signals of the nine MPPC are multiplexed by a charge division resistor network to generate four position-encoded analog outputs. Flood image, energy resolution and timing resolution measurements were performed using standard NIM electronics. The linearity of the detector response was investigated using gamma-ray sources of different energies. The 10 x 10 array of 0.8 mm LSO crystals was clearly resolved in the flood image. The average energy resolution and standard deviation were 20.0% full-width at half-maximum (FWHM) and ±5.0%, respectively, at 511 keV. The timing resolution of a single MPPC coupled to a LSO crystal was found to be 857 ps FWHM, and the value for the central region of detector module was 1182 ps FWHM when ±10% energy window was applied. The nonlinear response of a single MPPC when used to read out a single LSO was observed among the corner crystals of the proposed detector module. However, the central region of the detector module exhibits significantly less nonlinearity (6.5% for 511 keV). These results demonstrate that (1) a charge-sharing resistor network can effectively multiplex MPPC signals and reduce the number of output signals without significantly degrading the performance of a PET detector and (2) a custom light guide to permit light sharing

  10. Four-layer DOI PET detectors using a multi-pixel photon counter array and the light sharing method

    International Nuclear Information System (INIS)

    Nishikido, Fumihiko; Inadama, Naoko; Yoshida, Eiji; Murayama, Hideo; Yamaya, Taiga

    2013-01-01

    Silicon photomultipliers (SiPMs) provide many advantages for PET detectors, such as their high internal gain, high photon detection efficiency and insensitivity to magnetic fields. The number of detectable scintillation photons of SiPMs, however, is limited by the number of microcells. Therefore, pulse height of PET detectors using SiPMs is saturated when large numbers of scintillation photons enter the SiPM pixels. On the other hand, we previously presented a depth-of-interaction (DOI) encoding method that is based on the light sharing method. Since our encoding method detects scintillation photons with multiple readout pixels, the saturation effect can be suppressed. We constructed two prototype four-layer DOI detectors using a SiPM array and evaluated their performances. The two prototype detectors consisted of four layers of a 6×6 array of Lu 2(1−x) Y 2x SiO 5 (LYSO) crystals and a SiPM (multi-pixel photon detector, MPPC, Hamamatsu Photonics K.K.) array of 4×4 pixels. The size of each LYSO crystal element was 1.46 mm×1.46 mm×4.5 mm and all surfaces of the crystal elements were chemically etched. We used two types of MPPCs. The first one had 3600 microcells and high photon detection efficiency (PDE). The other one had 14,400 microcells and lower PDE. In the evaluation experiment, all the crystals of the detector using the MPPC which had the high PDE were clearly identified. The respective energy and timing resolutions of lower than 15% and 1.0 ns were achieved for each crystal element. No saturation of output signals was observed in the 511 keV energy region due to suppression of the saturation effect by detecting scintillation photons with several MPPC pixels by the light sharing method. -- Highlights: •We constructed and evaluated four-layer DOI detectors by the light sharing method using a MPPC array. •The detectors using two types of the MPPC array were compared. •The energy and timing resolutions of lower than 15% and 1.0 ns were achieved for

  11. Four-layer DOI PET detectors using a multi-pixel photon counter array and the light sharing method

    Energy Technology Data Exchange (ETDEWEB)

    Nishikido, Fumihiko, E-mail: funis@nirs.go.jp; Inadama, Naoko; Yoshida, Eiji; Murayama, Hideo; Yamaya, Taiga

    2013-11-21

    Silicon photomultipliers (SiPMs) provide many advantages for PET detectors, such as their high internal gain, high photon detection efficiency and insensitivity to magnetic fields. The number of detectable scintillation photons of SiPMs, however, is limited by the number of microcells. Therefore, pulse height of PET detectors using SiPMs is saturated when large numbers of scintillation photons enter the SiPM pixels. On the other hand, we previously presented a depth-of-interaction (DOI) encoding method that is based on the light sharing method. Since our encoding method detects scintillation photons with multiple readout pixels, the saturation effect can be suppressed. We constructed two prototype four-layer DOI detectors using a SiPM array and evaluated their performances. The two prototype detectors consisted of four layers of a 6×6 array of Lu{sub 2(1−x)}Y{sub 2x}SiO{sub 5} (LYSO) crystals and a SiPM (multi-pixel photon detector, MPPC, Hamamatsu Photonics K.K.) array of 4×4 pixels. The size of each LYSO crystal element was 1.46 mm×1.46 mm×4.5 mm and all surfaces of the crystal elements were chemically etched. We used two types of MPPCs. The first one had 3600 microcells and high photon detection efficiency (PDE). The other one had 14,400 microcells and lower PDE. In the evaluation experiment, all the crystals of the detector using the MPPC which had the high PDE were clearly identified. The respective energy and timing resolutions of lower than 15% and 1.0 ns were achieved for each crystal element. No saturation of output signals was observed in the 511 keV energy region due to suppression of the saturation effect by detecting scintillation photons with several MPPC pixels by the light sharing method. -- Highlights: •We constructed and evaluated four-layer DOI detectors by the light sharing method using a MPPC array. •The detectors using two types of the MPPC array were compared. •The energy and timing resolutions of lower than 15% and 1.0 ns were

  12. Scintillator counters with multi-pixel avalanche photodiode readout for the ND280 detector of the T2K experiment

    International Nuclear Information System (INIS)

    Mineev, O.; Afanasjev, A.; Bondarenko, G.; Golovin, V.; Gushchin, E.; Izmailov, A.; Khabibullin, M.; Khotjantsev, A.; Kudenko, Yu.; Kurimoto, Y.; Kutter, T.; Lubsandorzhiev, B.; Mayatski, V.; Musienko, Yu.; Nakaya, T.; Nobuhara, T.; Shaibonov, B.A.J.; Shaikhiev, A.; Taguchi, M.; Yershov, N.; Yokoyama, M.

    2007-01-01

    The Tokai-to-Kamioka (T2K) experiment is a second generation long baseline neutrino oscillation experiment which aims at a sensitive search for ν e appearance. The main design features of the T2K near neutrino detectors located at 280m from the target are presented, and the scintillator counters are described. The counters are readout via WLS fibers embedded into S-shaped grooves in the scintillator from both ends by multi-pixel avalanche photodiodes operating in a limited Geiger mode. Operating principles and results of tests of photosensors with a sensitive area of 1mm 2 are presented. A time resolution of 1.75ns, a spatial resolution of 9.9-12.4cm, and a detection efficiency for minimum ionizing particles of more than 99% were obtained for scintillator detectors in a beam test

  13. Investigation of Avalanche Photodiodes and Multipixel Photon Counters as Light Detectors for Cosmic Rays

    Science.gov (United States)

    Vasquez, Jaime; Saavedra, Arthur; Ramos, Roxana; Tavares, Pablo; Wade, Marcus; Fan, Sewan; Haag, Brooke

    2013-04-01

    Through the Research Scholars Institute, students of Hartnell Community College experimented with the application of avalanche photodiodes (APDs) as cosmic ray detectors during the summer of 2012. An APD detector was coupled with a 10 meter long wavelength shifting fiber (WSF) wrapped around a cylindrical plastic scintillator to maximize signal detection. A photomultiplier tube (PMT) was used in conjunction to detect the same scintillation light caused by incoming cosmic rays. Two APD detectors were evaluated to confirm the viability of the setup. In addition, a similar setup was recently utilized to implement multi-pixel photon counters (MPPCs) as readout detectors. Under this configuration, a high gain preamplifier was used to amplify the signals for both the MPPC and APD detectors. We report on our results characterizing the MPPC and discuss its overall performance. Compared to the APD, our findings suggest that the MPPC detector has greater sensitivity in detecting weak light signals, and can be used in place of the PMT for certain counting applications.

  14. Photon detection in ring imaging Cherenkov counters

    International Nuclear Information System (INIS)

    Jansen, H.

    1988-01-01

    One of the parts of DELPHI (a detector at the CERN LEP) is the barrel-RICH which uses Cherenkov radiation to determine the velocity of charged particles; together with the measured momentum this information yields the mass of each particle. The performance of the photon detector, which determines to a large extent the analyzing power of the barrel-RICH, is studied. 98 refs.; 40 figs.; 6 tabs

  15. Selective photon counter for digital x-ray mammography tomosynthesis

    Science.gov (United States)

    Goldan, Amir H.; Karim, Karim S.; Rowlands, J. A.

    2006-03-01

    Photon counting is an emerging detection technique that is promising for mammography tomosynthesis imagers. In photon counting systems, the value of each image pixel is equal to the number of photons that interact with the detector. In this research, we introduce the design and implementation of a low noise, novel selective photon counting pixel for digital mammography tomosynthesis in crystalline silicon CMOS (complementary metal oxide semiconductor) 0.18 micron technology. The design comprises of a low noise charge amplifier (CA), two low offset voltage comparators, a decision-making unit (DMU), a mode selector, and a pseudo-random counter. Theoretical calculations and simulation results of linearity, gain, and noise of the photon counting pixel are presented.

  16. Blocking Losses With a Photon Counter

    Science.gov (United States)

    Moision, Burce E.; Piazzolla, Sabino

    2012-01-01

    It was not known how to assess accurately losses in a communications link due to photodetector blocking, a phenomenon wherein a detector is rendered inactive for a short time after the detection of a photon. When used to detect a communications signal, blocking leads to losses relative to an ideal detector, which may be measured as a reduction in the communications rate for a given received signal power, or an increase in the signal power required to support the same communications rate. This work involved characterizing blocking losses for single detectors and arrays of detectors. Blocking may be mitigated by spreading the signal intensity over an array of detectors, reducing the count rate on any one detector. A simple approximation was made to the blocking loss as a function of the probability that a detector is unblocked at a given time, essentially treating the blocking probability as a scaling of the detection efficiency. An exact statistical characterization was derived for a single detector, and an approximation for multiple detectors. This allowed derivation of several accurate approximations to the loss. Methods were also derived to account for a rise time in recovery, and non-uniform illumination due to diffraction and atmospheric distortion of the phase front. It was assumed that the communications signal is intensity modulated and received by an array of photon-counting photodetectors. For the purpose of this analysis, it was assumed that the detectors are ideal, in that they produce a signal that allows one to reproduce the arrival times of electrons, produced either as photoelectrons or from dark noise, exactly. For single detectors, the performance of the maximum-likelihood (ML) receiver in blocking is illustrated, as well as a maximum-count (MC) receiver, that, when receiving a pulse-position-modulated (PPM) signal, selects the symbol corresponding to the slot with the largest electron count. Whereas the MC receiver saturates at high count rates

  17. SiPM as photon counter for Cherenkov detectors

    International Nuclear Information System (INIS)

    Roy, B.J.; Orth, H.; Schwarz, C.; Wilms, A.; Peters, K.

    2009-01-01

    Silicon photomultipliers (SiPMs) are very new type of photon counting devices that show great promise to be used as detection device in combination with scintillators/ Cherenkov radiators. SiPM is essentially an avalanche photo-diode operated in limited Geiger mode. They have been considered as potential readout devices for DIRC counter of the PANDA detector which is one of the large experiment at FAIR- the new international facility to be built at GSI, Darmstadt. In addition, the potential use of SiPM includes medical diagnosis, fluorescence measurement and high energy physics experiments. The SiPM module is a photon counting device capable of low light level detection. It is essentially an opto-semiconductor device with excellent photon counting capability and possesses great advantages over the conventional PMTs because of low voltage operation and insensitivity to magnetic fields. In many of the high energy physics experiments, the photon sensors are required to operate in high magnetic fields precluding the use of conventional PMTs. This problem can be over come with the use of SiPMs. With this motivation in mind, we have developed a SiPM test facility and have tested several commercially available SiPM for their performance study and comparison with other photon counting devices

  18. Visible light photon counters (VLPCs) for high rate tracking medical imaging and particle astrophysics

    International Nuclear Information System (INIS)

    Atac, M.

    1998-02-01

    This paper is on the operation principles of the Visible Light Photon Counters (VLPCs), application to high luminosity-high multiplicity tracking for High Energy Charged Particle Physics, and application to Medical Imaging and Particle Astrophysics. The VLPCs as Solid State Photomultipliers (SSPMS) with high quantum efficiency can detect down to single photons very efficiently with excellent time resolution and high avalanche gains

  19. Photon veto counters at KTeV/KAMI with blue WLS fibers

    International Nuclear Information System (INIS)

    Hanagaki, Kazunori

    1998-01-01

    The photon veto detectors used in KTeV experiment were required to have high detection efficiency with high speed response. To satisfy the requirements, we used scintillation counters with blue wave length shifter fibers for their readout. This document describes the design and performance of the photon veto detectors and a possible improvement for future experiments

  20. Compact Gaussian quantum computation by multi-pixel homodyne detection

    International Nuclear Information System (INIS)

    Ferrini, G; Fabre, C; Treps, N; Gazeau, J P; Coudreau, T

    2013-01-01

    We study the possibility of producing and detecting continuous variable cluster states in an extremely compact optical setup. This method is based on a multi-pixel homodyne detection system recently demonstrated experimentally, which includes classical data post-processing. It allows the incorporation of the linear optics network, usually employed in standard experiments for the production of cluster states, in the stage of the measurement. After giving an example of cluster state generation by this method, we further study how this procedure can be generalized to perform Gaussian quantum computation. (paper)

  1. Frequency-tuned microwave photon counter based on a superconductive quantum interferometer

    Science.gov (United States)

    Shnyrkov, V. I.; Yangcao, Wu; Soroka, A. A.; Turutanov, O. G.; Lyakhno, V. Yu.

    2018-03-01

    Various types of single-photon counters operating in infrared, ultraviolet, and optical wavelength ranges are successfully used to study electromagnetic fields, analyze radiation sources, and solve problems in quantum informatics. However, their operating principles become ineffective at millimeter band, S-band, and ultra-high frequency bands of wavelengths due to the decrease in quantum energy by 4-5 orders of magnitude. Josephson circuits with discrete Hamiltonians and qubits are a good foundation for the construction of single-photon counters at these frequencies. This paper presents a frequency-tuned microwave photon counter based on a single-junction superconducting quantum interferometer and flux qutrit. The control pulse converts the interferometer into a two-level system for resonance absorption of photons. Decay of the photon-induced excited state changes the magnetic flux in the interferometer, which is measured by a SQUID magnetometer. Schemes for recording the magnetic flux using a DC SQUID or ideal parametric detector, based on a qutrit with high-frequency excitation, are discussed. It is shown that the counter consisting of an interferometer with a Josephson junction and a parametric detector demonstrates high performance and is capable of detecting single photons in a microwave band.

  2. Integrated Lens Antennas for Multi-Pixel Receivers

    Science.gov (United States)

    Lee, Choonsup; Chattopadhyay, Goutam

    2011-01-01

    Future astrophysics and planetary experiments are expected to require large focal plane arrays with thousands of detectors. Feedhorns have excellent performance, but their mass, size, fabrication challenges, and expense become prohibitive for very large focal plane arrays. Most planar antenna designs produce broad beam patterns, and therefore require additional elements for efficient coupling to the telescope optics, such as substrate lenses or micromachined horns. An antenna array with integrated silicon microlenses that can be fabricated photolithographically effectively addresses these issues. This approach eliminates manual assembly of arrays of lenses and reduces assembly errors and tolerances. Moreover, an antenna array without metallic horns will reduce mass of any planetary instrument significantly. The design has a monolithic array of lens-coupled, leaky-wave antennas operating in the millimeter- and submillimeter-wave frequencies. Electromagnetic simulations show that the electromagnetic fields in such lens-coupled antennas are mostly confined in approximately 12 15 . This means that one needs to design a small-angle sector lens that is much easier to fabricate using standard lithographic techniques, instead of a full hyper-hemispherical lens. Moreover, this small-angle sector lens can be easily integrated with the antennas in an array for multi-pixel imager and receiver implementation. The leaky antenna is designed using double-slot irises and fed with TE10 waveguide mode. The lens implementation starts with a silicon substrate. Photoresist with appropriate thickness (optimized for the lens size) is spun on the substrate and then reflowed to get the desired lens structure. An antenna array integrated with individual lenses for higher directivity and excellent beam profile will go a long way in realizing multi-pixel arrays and imagers. This technology will enable a new generation of compact, low-mass, and highly efficient antenna arrays for use in multi-pixel

  3. A compact readout system for multi-pixel hybrid photodiodes

    International Nuclear Information System (INIS)

    Datema, C.P.; Meng, L.J.; Ramsden, D.

    1999-01-01

    Although the first Multi-pixel Hybrid Photodiode (M-HPD) was developed in the early 1990s by Delft Electronic Products, the main obstacle to its application has been the lack of availability of a compact read-out system. A fast, parallel readout system has been constructed for use with the earlier 25-pixel tube with High-energy Physics applications in mind. The excellent properties of the recently developed multi-pixel hybrid photodiodes (M-HPD) will be easier to exploit following the development of the new hybrid read-out circuits described in this paper. This system will enable all of the required read-out functions to be accommodate on a single board into which the M-HPD is plugged. The design and performance of a versatile system is described in which a trigger-signal, derived from the common-side of the silicon anode in the M-HPD, is used to trigger the readout of the 60-anode pixels in the M-HPD. The multi-channel amplifier section is based on the use of a new, commercial VLSI chip, whilst the read-out sequencer uses a chip of its own design. The common anode signal is processed by a fast amplifier and discriminator to provide a trigger signal when a single event is detected. In the prototype version, the serial analogue output data-stream is processed using a PC-mounted, high speed ADC. Results obtained using the new read-out system in a compact gamma-camera and with a small muon tracking-chamber demonstrate the low-noise performance of the system. The application of this read-out system in other position-sensitive or multi-anode photomultiplier tube applications are also described

  4. Polarimetric analysis of a CdZnTe spectro-imager under multi-pixel irradiation conditions

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, M. [LIP-Laboratório de Instrumentação e Física Experimental de Partículas (Portugal); Physics Department, University of Coimbra, Coimbra (Portugal); Curado da Silva, R.M., E-mail: rui.silva@coimbra.lip.pt [LIP-Laboratório de Instrumentação e Física Experimental de Partículas (Portugal); Physics Department, University of Coimbra, Coimbra (Portugal); Maia, J.M. [LIP-Laboratório de Instrumentação e Física Experimental de Partículas (Portugal); Physics Department, University of Beira-Interior, Covilhã (Portugal); Simões, N. [LIP-Laboratório de Instrumentação e Física Experimental de Partículas (Portugal); Physics Department, University of Coimbra, Coimbra (Portugal); Marques, J. [LIP-Laboratório de Instrumentação e Física Experimental de Partículas (Portugal); Centro de Astrofísica, Universidade do Porto, Porto (Portugal); Pereira, L.; Trindade, A.M.F. [LIP-Laboratório de Instrumentação e Física Experimental de Partículas (Portugal); and others

    2016-12-21

    So far, polarimetry in high-energy astrophysics has been insufficiently explored due to the complexity of the required detection, electronic and signal processing systems. However, its importance is today largely recognized by the astrophysical community, therefore the next generation of high-energy space instruments will certainly provide polarimetric observations, contemporaneously with spectroscopy and imaging. We have been participating in high-energy observatory proposals submitted to ESA Cosmic Vision calls, such as GRI (Gamma-Ray Imager), DUAL and ASTROGAM, where the main instrument was a spectro-imager with polarimetric capabilities. More recently, the H2020 AHEAD project was launched with the objective to promote more coherent and mature future high-energy space mission proposals. In this context of high-energy proposal development, we have tested a CdZnTe detection plane prototype polarimeter under a partially polarized gamma-ray beam generated from an aluminum target irradiated by a {sup 22}Na (511 keV) radioactive source. The polarized beam cross section was 1 cm{sup 2}, allowing the irradiation of a wide multi-pixelated area where all the pixels operate simultaneously as a scatterer and as an absorber. The methods implemented to analyze such multi-pixel irradiation are similar to those required to analyze a spectro-imager polarimeter operating in space, since celestial source photons should irradiate its full pixilated area. Correction methods to mitigate systematic errors inherent to CdZnTe and to the experimental conditions were also implemented. The polarization level (~40%) and the polarization angle (precision of ±5° up to ±9°) obtained under multi-pixel irradiation conditions are presented and compared with simulated data.

  5. Scintillating fiber tracking at high luminosities using Visible Light Photon counter readout

    International Nuclear Information System (INIS)

    Atac, M.

    1995-11-01

    This paper reviews the research work on the Visible Light Photon Counters (VLPC) that have been developed for the scintillating fiber tracking at high luminosity colliders and high rate fixed target experiments. The devices originated from the joint work between UCLA and Rockwell International Science Center. The VLPCs are capable of counting photons very efficiently down to a single photon level with high avalanche gain, producing pulses at very high rates with very short rise times. Due to small gain dispersions they can be used in counting photons with high quantum efficiencies, therefore they are excellent devices for charged particle tracking using small diameter scintillating plastic fibers. In this paper, fiber tracking for the CDF and D0 upgrades and a possible usage of the VLPC readout for the experiment E803 at Fermilab will be discussed

  6. Search for ultra-high energy photons with AMIGA muon counters

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Nicolas Martin [Instituto de Tecnologias en Deteccion y Astroparticulas, Buenos Aires (Argentina); Institut fuer Kernphysik, Karlsruher Institut fuer Technologie. (Germany); Collaboration: Pierre-Auger-Collaboration

    2016-07-01

    The study of the composition of ultra-high energy (UHE) cosmic rays (CR) is one of the topical problems of astroparticle physics. The discovery of UHE photons, i.e. photons with energies around 1 EeV, in primary cosmic rays could be of particular interest for the field of astroparticle physics, and also for fundamental physics, since they are tracers of the highest-energy processes in the Universe. For the search for UHE photons at the Pierre Auger Observatory (PAO), several parameters have been proposed to distinguish between primary hadrons and photons. One of the most promising approaches to search for primary gamma rays is the study of the muon component in extensive air showers (EAS) produced in the interaction between the CR and the nuclei in the atmosphere. The number of muons in showers induced by gamma primaries is an order of magnitude lower than the hadronic primaries counterpart. The AMIGA extension of the PAO, consisting of an array of buried scintillators counters, allows the study of the muons produced during the EAS development. In this talk, the sensitivity of the muon counters to photon-initiated EAS and the possible discrimination procedures are discussed using dedicated EAS simulations with software package CORSIKA, including the detector response using the Offline package developed by the Pierre Auger Collaboration.

  7. The multichannel amplifier/discriminator CMOS ASIC for visual light photon counters

    International Nuclear Information System (INIS)

    Baturitsky, M.A.; Yurenya, Yu.P.Yu.P.

    2002-01-01

    The 18-channel CMOS custom monolithic amplifier/discriminator ASIC was designed as a front-end electronics chip for Visual Light Photon Counters which convert photons from scintillation fibre/strip detectors to electrical signals. One ASICs channel contains a charge-sensitive preamplifier, a discriminator to mark the arrival time of signals, and a charge divider to provide analog outputs for analog-to-digital conversion being performed by SVX2. The ASIC is proposed as one of the variants for possible future front-end electronics upgrading the D0 Central Fibre Tracker, Central and Forward Pre-Showers (Fermilab, Batavia, USA)

  8. Study of micro pixel photon counters for a high granularity scintillator-based hadron calorimeter

    International Nuclear Information System (INIS)

    D'Ascenzo, N.; Eggemann, A.; Garutti, E.

    2007-11-01

    A new Geiger mode avalanche photodiode, the Micro Pixel Photon Counter (MPPC), was recently released by Hamamatsu. It has a high photo-detection efficiency in the 420 nm spectral region. This product can represent an elegant candidate for the design of a high granularity scintillator based hadron calorimeter for the International Linear Collider. In fact, the direct readout of the blue scintillation photons with a MPPC is a feasible techological solution. The readout of a plastic scintillator by a MPPC, both mediated by the traditional wavelength shifting fiber, and directly coupled, has been systematically studied. (orig.)

  9. High-throughput gated photon counter with two detection windows programmable down to 70 ps width

    Energy Technology Data Exchange (ETDEWEB)

    Boso, Gianluca; Tosi, Alberto, E-mail: alberto.tosi@polimi.it; Zappa, Franco [Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Piazza Leonardo Da Vinci 32, 20133 Milano (Italy); Mora, Alberto Dalla [Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo Da Vinci 32, 20133 Milano (Italy)

    2014-01-15

    We present the design and characterization of a high-throughput gated photon counter able to count electrical pulses occurring within two well-defined and programmable detection windows. We extensively characterized and validated this instrument up to 100 Mcounts/s and with detection window width down to 70 ps. This instrument is suitable for many applications and proves to be a cost-effective and compact alternative to time-correlated single-photon counting equipment, thanks to its easy configurability, user-friendly interface, and fully adjustable settings via a Universal Serial Bus (USB) link to a remote computer.

  10. Quality Assurance of Pixel Hybrid Photon Detectors for the LHCb Ring Imaging Cherenkov Counters

    CERN Document Server

    Carson, Laurence

    Pion/kaon discrimination in the LHCb experiment will be provided by two Ring Imaging Cherenkov (RICH) counters. These use arrays of 484 Hybrid Photon Detectors (HPDs) to detect the Cherenkov photons emitted by charged particles traversing the RICH. The results from comprehensive quality assurance tests on the 550 HPDs manufactured for LHCb are described. Leakage currents, dead channel probabilities, dark count rates and ion feedback rates are reported. Furthermore, measurements carried out on a sample of tubes to determine the efficiency of the HPD pixel chip by measuring the summed analogue response from the backplane of the silicon sensor are described.

  11. High-throughput gated photon counter with two detection windows programmable down to 70 ps width

    International Nuclear Information System (INIS)

    Boso, Gianluca; Tosi, Alberto; Zappa, Franco; Mora, Alberto Dalla

    2014-01-01

    We present the design and characterization of a high-throughput gated photon counter able to count electrical pulses occurring within two well-defined and programmable detection windows. We extensively characterized and validated this instrument up to 100 Mcounts/s and with detection window width down to 70 ps. This instrument is suitable for many applications and proves to be a cost-effective and compact alternative to time-correlated single-photon counting equipment, thanks to its easy configurability, user-friendly interface, and fully adjustable settings via a Universal Serial Bus (USB) link to a remote computer

  12. Design and Optimization of Multi-Pixel Transition-Edge Sensors for X-Ray Astronomy Applications

    Science.gov (United States)

    Smith, Stephen J.; Adams, Joseph S.; Bandler, Simon R.; Chervenak, James A.; Datesman, Aaron Michael; Eckart, Megan E.; Ewin, Audrey J.; Finkbeiner, Fred M.; Kelley, Richard L.; Kilbourne, Caroline A.; hide

    2017-01-01

    Multi-pixel transition-edge sensors (TESs), commonly referred to as 'hydras', are a type of position sensitive micro-calorimeter that enables very large format arrays to be designed without commensurate increase in the number of readout channels and associated wiring. In the hydra design, a single TES is coupled to discrete absorbers via varied thermal links. The links act as low pass thermal filters that are tuned to give a different characteristic pulse shape for x-ray photons absorbed in each of the hydra sub pixels. In this contribution we report on the experimental results from hydras consisting of up to 20 pixels per TES. We discuss the design trade-offs between energy resolution, position discrimination and number of pixels and investigate future design optimizations specifically targeted at meeting the readout technology considered for Lynx.

  13. Performance Studies of Pixel Hybrid Photon Detectors for the LHCb RICH Counters

    CERN Document Server

    Aglieri Rinella, G; Piedigrossi, D; Van Lysebetten, A

    2004-01-01

    The Pixel Hybrid Photon Detector is a vacuum tube with a multi-alkali photo cathode, high voltage cross-focused electron optics and an anode consisting of a silicon pixel detector bump-bonded to a readout CMOS electronic chip fully encapsulated in the device. The Pixel HPD fulfils the requirements of the Ring Imaging Cherenkov counters of the LHCb experiment at LHC. The performances of the Pixel HPD will be discussed with reference to laboratory measurements, Cherenkov light imaging in recent beam tests, image distortions due to a magnetic field.

  14. On a Search for Hidden Photon CDM by a Multicathode Counter

    International Nuclear Information System (INIS)

    Petukhov, V. V.; Kopylov, A. V.; Orekhov, I. V.

    2016-01-01

    We report a new technique of a multicathode counter (MCC) developed to search for hidden photon (HP) cold dark matter (CDM) with a mass from 5 to 500 eV. The method is suggested in the assumption that HP-photon mixing causes emission of single electrons from a metal cathode if the mass of hidden photon m_γ_"′ is greater than a work function of the metal φ_W. The measured effect from HP should be dependent on φ_W and on the structure of electronic shells of the metal used as a cathode. Potentially this can be used for a verification of the results obtained. Some preliminary results for the upper limit for mixing parameter χ have been obtained for HP with a mass from 5 eV to 10 keV as a pure illustration of the potential of this technique. The efforts are continued to refine the procedure of data treatment and to improve the work of MCC. A new detector with a more developed design is under construction.

  15. Background simulation for the Spherical Proportional Counter and its use for the detection of optical photons

    International Nuclear Information System (INIS)

    Bougamont, E; Colas, P; Dastgheibi-Fard, A; Derre, J; Giomataris, I; Gerbier, G; Gros, M; Magnier, P; Navick, X F; Tsiledakis, G; Salin, P; Savvidis, I; Vergados, J D

    2013-01-01

    The recently developed Spherical Proportional Counter [1] allows to instrument large target masses with good energy resolution and sub-keV energy threshold. The moderate cost of this detector, its simplicity and robustness, makes this technology a promising approach for many domains of physics and applications, like dark matter detection and low energy neutrino searches. Detailed Monte Carlo simulations are essential to evaluate the background level expected at the sub-keV energy regime. The simulated background here, it refers to the contribution of the construction material of the detector and the effect of the environmental gamma radiation. This detector due to its spherical shape could be also served as an optical photon detector provided it is equipped with PMTs, for Double Beta decay and Dark Matter searches. All calculations shown here are obtained using the FLUKA Monte Carlo code

  16. Performance of multiclad scintillating and clear waveguide fibers read out with visible light photon counters

    Energy Technology Data Exchange (ETDEWEB)

    Baumbaugh, B. (Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States)); Erdman, J. (Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States)); Gaskell, D. (Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States)); Lu, Q. (Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States)); Marchant, J. (Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States)); Ruchti, R. (Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States)); Wayne, M. (Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States)); Cooper, C. (Department of Physics, Purdue University, West Lafayette, IN 47907 (United States)); Hinson, J. (Department of Physics, Purdue University, West Lafayette, IN 47907 (United States)); Koltick, D.S. (Department of Physics, Purdue University, West Lafayette, IN 47907 (United State

    1994-06-15

    Measurements have been made of the performance of scintillating fibers read out with visible light photon counters (VLPCs). The light yields of single-clad and multiclad scintillating fibers have been compared. The experiment consisted of 3 m long scintillating fibers of 830 [mu]m diameter optically coupled to 8 m long waveguide fibers of 965 [mu]m diameter read out with HISTE-IV VLPCs. For the case of multiclad scintillating fiber and waveguide, an average of 6.2 photoelectrons was detected from the far end of the scintillating fiber if the fiber end was unmirrored, and 10.2 photoelectrons if the fiber end was mirrored. With this substantial photoelectron yield, minimum-ionizing tracks can be easily detected in fiber arrays, and excellent performance characteristics are expected for the fiber trackers designed for the D0 experiment at the Fermilab Tevatron Collider and the SDC experiment at the SSC Laboratory. ((orig.))

  17. TOPAS 1 - construction and test of a scintillation counter hodoscope for the tagging of bremsstrahlung photons for the SAPHIR detector

    International Nuclear Information System (INIS)

    Merkel, R.

    1989-09-01

    The development of a tagging-hodoscope for the SAPHIR-detector at the stretcher ring ELSA in Bonn is described. The hodoscope covers the energy range 2.175 GeV γ 0 =3.500 GeV. 24 scintillation counters are used for the determination of the photon energy, giving a resolution of ΔE γ =25 MeV. The tagging method requires a good coincidence timing resoluting τ between the tagging hodoscope and the detector for the photon-induced reactions in order to keep the accidental coincidences low. The timing information is given by 8 fast timing counters (40 mm thick), covering 5 up to 7 energy channels each. Fluctuations of the timing signal which result from different impact-locations on the timing counter, due to different light travelling distances, are corrected by the energy defining counters. The timing-component (8 timing counters) is commpleted and tested. The results of first mesurements show an upper limit of σ=250 psec for the resolution of 7 coincidences out of 45 possible channels in the tagging hodscope. These results are obtained with a preliminary adjustment of the SAPHIR beam-line and with a not yet optimized signal to noize ratio in the extracted beam. We hope to obtain a σ<200 psec under optimized conditions. (orig.)

  18. Scanning confocal slit photon counter measurements of post-PRK haze in two-year study

    Science.gov (United States)

    Taboada, John; Gaines, David; Perez, Mary A.; Waller, Steve G.; Ivan, Douglas J.; Baldwin, J. Bruce; LoRusso, Frank; Tutt, Ronald C.; Thompson, B.; Perez, Jose; Tredici, Thomas; Johnson, Dan A.

    2001-06-01

    In our study, a group of 80 United States Air Force, non- flying personnel will undergo photorefractive corneal surgery for moderate levels of myopia (< 6 diopters) and 20 will serve as controls. As of this report, approximately 56 have had the treatment. Of these, only about 59% of the treated eyes showed even a trace (.5) level of clinically assessed haze at any time. We report on the use of a recently developed instrument designed for the objective measurement of these low levels of haze in treated corneas. The sensitivity of the instrument is derived from the use of a scanning confocal slit photon counter. The use of a physical standard for calibration secures accuracy and reproducibility over an extensive period of time. Our haze measurements in this study revealed a very low level increase from baseline values for these patients. The typical increase over baseline was of the same magnitude as the variability in the observations, although the inherent variability in the measurements was approximately 0.25 times the value of the patient's haze variability.

  19. Photon and neutron dose discrimination using low pressure proportional counters with graphite and A150 walls

    International Nuclear Information System (INIS)

    Kylloenen, J.; Lindborg, L.

    2005-01-01

    Full text: The determination of both the low- and high-LET components of ambient dose equivalent in mixed fields is possible with microdosimetric methods. With the multiple-event microdosimetric variance covariance method the sum of those components are directly obtained also in pulsed beams. However, if the value of each dose component is needed a more extended analysis is required. The use of a graphite walled proportional detector in combination with a tissue-equivalent proportional counter in combination with the variance covariance method was here investigated. MCNP simulations were carried out for relevant energies to investigate the photon and neutron responses of the two detectors. The combined graphite and TEPC system, the Sievert instrument, was used for measurements at IRSN, Cadarache, in the workplace calibration fields of CANEL+, SIGMA, a Cf-252 and a moderated Cf(D 2 O,Cd) radiation field. The response of the instrument in various monoenergetic neutron fields is also known from measurements at PTB. The instrument took part in the measurement campaigns in workplace fields in the nuclear industry organized within the EVIDOS contract. The results are analyzed and the method of using a graphite detector compared with alternative methods of analysis is discussed. (author)

  20. On the basic mechanism of Pixelized Photon Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Otono, H. [Department of Physics, School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)], E-mail: otono@icepp.s.u-tokyo.ac.jp; Oide, H. [Department of Physics, School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Yamashita, S. [International Center for Elementary Particle Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Yoshioka, T. [Neutron Science Laboratory, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan)

    2009-10-21

    A Pixelized Photon Detector (PPD) is a generic name for the semiconductor devices operated in the Geiger-mode, such as Silicon PhotoMultiplier and Multi-Pixel Photon Counter, which has high photon counting capability. While the internal mechanisms of the PPD have been intensively studied in recent years, the existing models do not include the avalanche process. We have simulated the multiplication and quenching of the avalanche process and have succeeded in reproducing the output waveform of the PPD. Furthermore our model predicts the existence of dead-time in the PPD which has never been numerically predicted. For searching the dead-time, we also have developed waveform analysis method using deconvolution which has the potential to distinguish neighboring pulses precisely. In this paper, we discuss our improved model and waveform analysis method.

  1. A 30 ps Timing Resolution for Single Photons with Multi-pixel Burle MCP-PMT

    Energy Technology Data Exchange (ETDEWEB)

    Va' vra, J.; Benitez, J.; Coleman, J.; Leith, D.W.G.S.; Mazaheri, G.; Ratcliff, B.; Schwiening, J.; /SLAC

    2006-07-05

    We have achieved {approx}30 psec single-photoelectron and {approx}12ps for multi-photoelectron timing resolution with a new 64 pixel Burle MCP-PMT with 10 micron microchannel holes. We have also demonstrated that this detector works in a magnetic field of 15kG, and achieved a single-photoelectron timing resolution of better than 60 psec. The study is relevant for a new focusing DIRC RICH detector for particle identification at future Colliders such as the super B-factory or ILC, and for future TOF techniques. This study shows that a highly pixilated MCP-PMT can deliver excellent timing resolution.

  2. Photon-number discrimination without a photon counter and its application to reconstructing non-Gaussian states

    Energy Technology Data Exchange (ETDEWEB)

    Chrzanowski, H. M.; Bernu, J.; Sparkes, B. M.; Hage, B.; Lam, P. K.; Symul, T. [Centre for Quantum Computation and Communication Technology, Quantum Optics group, Department of Quantum Science, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia); Lund, A. P. [Centre for Quantum Computation and Communication Technology, Centre for Quantum Dynamics, Griffith University, Nathan QLD 4111 (Australia); Ralph, T. C. [Centre for Quantum Computation and Communication Technology, Department of Physics, University of Queensland, St. Lucia QLD 4072 (Australia)

    2011-11-15

    The nonlinearity of a conditional photon-counting measurement can be used to ''de-Gaussify'' a Gaussian state of light. Here we present and experimentally demonstrate a technique for photon-number resolution using only homodyne detection. We then apply this technique to inform a conditional measurement, unambiguously reconstructing the statistics of the non-Gaussian one- and two-photon-subtracted squeezed vacuum states. Although our photon-number measurement relies on ensemble averages and cannot be used to prepare non-Gaussian states of light, its high efficiency, photon-number-resolving capabilities, and compatibility with the telecommunications band make it suitable for quantum-information tasks relying on the outcomes of mean values.

  3. Photon-number discrimination without a photon counter and its application to reconstructing non-Gaussian states

    International Nuclear Information System (INIS)

    Chrzanowski, H. M.; Bernu, J.; Sparkes, B. M.; Hage, B.; Lam, P. K.; Symul, T.; Lund, A. P.; Ralph, T. C.

    2011-01-01

    The nonlinearity of a conditional photon-counting measurement can be used to ''de-Gaussify'' a Gaussian state of light. Here we present and experimentally demonstrate a technique for photon-number resolution using only homodyne detection. We then apply this technique to inform a conditional measurement, unambiguously reconstructing the statistics of the non-Gaussian one- and two-photon-subtracted squeezed vacuum states. Although our photon-number measurement relies on ensemble averages and cannot be used to prepare non-Gaussian states of light, its high efficiency, photon-number-resolving capabilities, and compatibility with the telecommunications band make it suitable for quantum-information tasks relying on the outcomes of mean values.

  4. Observing pure effects of counter-rotating terms without ultrastrong coupling: A single photon can simultaneously excite two qubits

    Science.gov (United States)

    Wang, Xin; Miranowicz, Adam; Li, Hong-Rong; Nori, Franco

    2017-12-01

    The coherent process that a single photon simultaneously excites two qubits has recently been theoretically predicted by Garziano et al. [L. Garziano, V. Macrì, R. Stassi, O. Di Stefano, F. Nori, and S. Savasta, One Photon Can Simultaneously Excite two or More Atoms, Phys. Rev. Lett. 117, 043601 (2016), 10.1103/PhysRevLett.117.043601]. We propose a different approach to observe a similar dynamical process based on a superconducting quantum circuit, where two coupled flux qubits longitudinally interact with the same resonator. We show that this simultaneous excitation of two qubits (assuming that the sum of their transition frequencies is close to the cavity frequency) is related to the counter-rotating terms in the dipole-dipole coupling between two qubits, and the standard rotating-wave approximation is not valid here. By numerically simulating the adiabatic Landau-Zener transition and Rabi-oscillation effects, we clearly verify that the energy of a single photon can excite two qubits via higher-order transitions induced by the longitudinal couplings and the counter-rotating terms. Compared with previous studies, the coherent dynamics in our system only involves one intermediate state and, thus, exhibits a much faster rate. We also find transition paths which can interfere. Finally, by discussing how to control the two longitudinal-coupling strengths, we find a method to observe both constructive and destructive interference phenomena in our system.

  5. First in situ TOF-PET study using digital photon counters for proton range verification.

    Science.gov (United States)

    Cambraia Lopes, P; Bauer, J; Salomon, A; Rinaldi, I; Tabacchini, V; Tessonnier, T; Crespo, P; Parodi, K; Schaart, D R

    2016-08-21

    Positron emission tomography (PET) is the imaging modality most extensively tested for treatment monitoring in particle therapy. Optimal use of PET in proton therapy requires in situ acquisition of the relatively strong (15)O signal due to its relatively short half-life (~2 min) and high oxygen content in biological tissues, enabling shorter scans that are less sensitive to biological washout. This paper presents the first performance tests of a scaled-down in situ time-of-flight (TOF) PET system based on digital photon counters (DPCs) coupled to Cerium-doped Lutetium Yttrium Silicate (LYSO:Ce) crystals, providing quantitative results representative of a dual-head tomograph that complies with spatial constraints typically encountered in clinical practice (2  ×  50°, of 360°, transaxial angular acceptance). The proton-induced activity inside polymethylmethacrylate (PMMA) and polyethylene (PE) phantoms was acquired within beam pauses (in-beam) and immediately after irradiation by an actively-delivered synchrotron pencil-beam, with clinically relevant 125.67 MeV/u, 4.6  ×  10(8) protons s(-1), and 10(10) total protons. 3D activity maps reconstructed with and without TOF information are compared to FLUKA simulations, demonstrating the benefit of TOF-PET to reduce limited-angle artefacts using a 382 ps full width at half maximum coincidence resolving time. The time-dependent contributions from different radionuclides to the total count-rate are investigated. We furthermore study the impact of the acquisition time window on the laterally integrated activity depth-profiles, with emphasis on 2 min acquisitions starting at different time points. The results depend on phantom composition and reflect the differences in relative contributions from the radionuclides originating from carbon and oxygen. We observe very good agreement between the shapes of the simulated and measured activity depth-profiles for post-beam protocols. However, our results

  6. Experimental study of photon fast detector with a cathodic lecture in check pattern for annular focusing Cherenkov counters

    International Nuclear Information System (INIS)

    Arnold, R.; Guyonnet, J.L.; Giomataris, Y.; Seguinot, J.; Ypsilantis, T.

    1990-01-01

    It's about the experimental study of a photodetector for Cherenkov counters, able to separate events of a high multiplicity belonging to two successive collisions of beams (Interaction rate - 100 MHz for a luminosity of 10 33 cm -2 sec -1 at SSC). The detailed tests of the photodetector have been made to know its answer. (detection efficiency, rapidity, geometric resolution, reconstruction), to optimalize its geometry but also to elaborate and to test a Monte Carlo simulation program which can predict the comportment and the reconstruction resolution of a detector for several granularities of lecture for different devices of photon-electron converters or operation gases [fr

  7. Fluctuation mechanisms in superconductors nanowire single-photon counters, enabled by effective top-down manufacturing

    CERN Document Server

    Bartolf, Holger

    2016-01-01

    Holger Bartolf discusses state-of-the-art detection concepts based on superconducting nanotechnology as well as sophisticated analytical formulæ that model dissipative fluctuation-phenomena in superconducting nanowire single-photon detectors. Such knowledge is desirable for the development of advanced devices which are designed to possess an intrinsic robustness against vortex-fluctuations and it provides the perspective for honorable fundamental science in condensed matter physics. Especially the nanowire detector allows for ultra-low noise detection of signals with single-photon sensitivity and GHz repetition rates. Such devices have a huge potential for future technological impact and might enable unique applications (e.g. high rate interplanetary deep-space data links from Mars to Earth). Contents Superconducting Single-Photon Detectors Nanotechnological Manufacturing; Scale: 10 Nanometer Berezinskii-Kosterlitz Thouless (BKT) Transition, Edge-Barrier, Phase Slips Target Groups Researchers and students of...

  8. MPGD-based counters of single photons developed for COMPASS RICH-1

    Czech Academy of Sciences Publication Activity Database

    Alexeev, M.; Birsa, R.; Bodlak, M.; Bradamante, F.; Bressan, A.; Büchele, M.; Chiosso, M.; Ciliberti, P.; Dalla Torre, S.; Dasgupta, S.; Denisov, O.; Duic, V.; Finger, M.; Finger jr., M.; Fischer, H.; Giorgi, M.; Gobbo, B.; Gregori, M.; Herrmann, F.; Königsmann, K.; Levorato, S.; Maggiora, A.; Martin, A.; Menon, G.; Nováková, Kateřina; Nový, J.; Panzieri, D.; Pereira, F.A.; Santos, C.A.; Sbrizzai, G.; Schiavon, P.; Schorb, S.; Slunečka, M.; Sozzi, F.; Steiger, Lukáš; Sulc, M.; Tessarotto, F.; Veloso, J.F.C.A.

    2014-01-01

    Roč. 9, č. 9 (2014), C09017-C09017 ISSN 1748-0221. [International Conference on Instrumentation for Colliding Beam Physics. Budker Inst Nucl Phys, Novosibirsk, 24.02.2014-01.03.2014] Institutional support: RVO:61389021 Keywords : Hybrid detectors * Micropattern gaseous detectors (MSGC, GEM, THGEM, RETHGEM, MHSP, MICROPIC, MICROMEGAS, InGrid, etc) * Electron multipliers (gas) * visible and IR photons (gas) (gas-photocathodes, solid-photocathodes) * Photon detectors for UV Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.399, year: 2014 http://iopscience.iop.org/1748-0221/9/09/C09017/pdf/1748-0221_9_09_C09017.pdf

  9. TH-D-BRC-00: Educational Point Counter/Point: Has Photon RT Hit the Limits?

    International Nuclear Information System (INIS)

    2016-01-01

    Interest in proton therapy has increased dramatically in the past couple of years, especially in the United States. There certainly is an important place for proton therapy in the arsenal of cancer treatments. Its dosimetric advantage and potential for low toxicity makes it the perfect partner for photons and other cancer treatment modalities. Often there is a belief that the new technology ought to be better but many believe that they should be widely adopted in the clinic only after evidence has shown that they are at least as safe and efficacious as existing technologies, which are often less expensive. This is the case for proton radiotherapy. This session being both educational and debate will provide a good review of basics and technological advancement as well as a comprehensive clinical update for both proton and photon therapy. Future technology developments and how they will impact the potential dosimetric advantage of proton therapy will be discussed. Particularly the debate will focus on whether these developments will close or widen the gap between photon and proton therapy. Learning Objectives: To review challenges, limitations, and recent and future developments in proton therapy. To review challenges, limitations, recent and future developments in photon radiotherapy. To review current clinical trials and challenging clinical cases. C. Yu, No company or organization that my presentation mentions provided me with financial support. I am the Founder and CEO of Xcision Medical Systems, LLC. However, my presentation will not mention any product or technology developed by Xcision.

  10. TH-D-BRC-00: Educational Point Counter/Point: Has Photon RT Hit the Limits?

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2016-06-15

    Interest in proton therapy has increased dramatically in the past couple of years, especially in the United States. There certainly is an important place for proton therapy in the arsenal of cancer treatments. Its dosimetric advantage and potential for low toxicity makes it the perfect partner for photons and other cancer treatment modalities. Often there is a belief that the new technology ought to be better but many believe that they should be widely adopted in the clinic only after evidence has shown that they are at least as safe and efficacious as existing technologies, which are often less expensive. This is the case for proton radiotherapy. This session being both educational and debate will provide a good review of basics and technological advancement as well as a comprehensive clinical update for both proton and photon therapy. Future technology developments and how they will impact the potential dosimetric advantage of proton therapy will be discussed. Particularly the debate will focus on whether these developments will close or widen the gap between photon and proton therapy. Learning Objectives: To review challenges, limitations, and recent and future developments in proton therapy. To review challenges, limitations, recent and future developments in photon radiotherapy. To review current clinical trials and challenging clinical cases. C. Yu, No company or organization that my presentation mentions provided me with financial support. I am the Founder and CEO of Xcision Medical Systems, LLC. However, my presentation will not mention any product or technology developed by Xcision.

  11. Investigation of photon detection probability dependence of SPADnet-I digital photon counter as a function of angle of incidence, wavelength and polarization

    Energy Technology Data Exchange (ETDEWEB)

    Játékos, Balázs, E-mail: jatekosb@eik.bme.hu; Ujhelyi, Ferenc; Lőrincz, Emőke; Erdei, Gábor

    2015-01-01

    SPADnet-I is a prototype, fully digital, high spatial and temporal resolution silicon photon counter, based on standard CMOS imaging technology, developed by the SPADnet consortium. Being a novel device, the exact dependence of photon detection probability (PDP) of SPADnet-I was not known as a function of angle of incidence, wavelength and polarization of the incident light. Our targeted application area of this sensor is next generation PET detector modules, where they will be used along with LYSO:Ce scintillators. Hence, we performed an extended investigation of PDP in a wide range of angle of incidence (0° to 80°), concentrating onto a 60 nm broad wavelength interval around the characteristic emission peak (λ=420 nm) of the scintillator. In the case where the sensor was optically coupled to a scintillator, our experiments showed a notable dependence of PDP on angle, polarization and wavelength. The sensor has an average PDP of approximately 30% from 0° to 60° angle of incidence, where it starts to drop rapidly. The PDP turned out not to be polarization dependent below 30°. If the sensor is used without a scintillator (i.e. the light source is in air), the polarization dependence is much less expressed, it begins only from 50°.

  12. Cherenkov light imaging tests with state-of-the-art solid state photon counter for the CLAS12 RICH detector

    Science.gov (United States)

    Balossino, Ilaria; Barion, L.; Contalbrigo, M.; Lenisa, P.; Lucherini, V.; Malaguti, R.; Mirazita, M.; Movsisyan, A.; Squerzanti, S.; Turisini, M.

    2017-12-01

    A large area ring-imaging Cherenkov detector will be operated for hadron identification in the 3 GeV / c to 8 GeV / c momentum range at the CLAS12 experiment at the upgraded continuous electron beam accelerator facility of Jefferson Lab. The detector, consisting of aerogel radiator, composite mirrors and photon counters, will be built with a hybrid optics design to allow the detection of Cherenkov light for both forward and large angle hadron tracks. The active area has to be densely packed and highly segmented, covering about 1m2 with pixels of 6mm2 , and to allow a time resolution of 1 ns. A technology that can offer a cost-effective solution and low material budget could be Silicon Photomultipliers (SiPM) thanks to their high gain at low bias voltage, fast timing, good single-photoelectron resolution and insensitivity to magnetic fields. An investigation is ongoing on samples of 3 × 3mm2 SiPM of different micro-cell size to assess the single photon detection capability in the presence of high dark count rate due to thermal generation effects, after-pulses or optical cross-talk and to study the response to the moderate radiation damage expected at CLAS12. In this work, a brief review of the latest and most interesting results from these studies will be shown.

  13. Study of multi-pixel Geiger-mode avalanche photodiodes as a read-out for PET

    CERN Document Server

    Musienko, Yuri; Lecoq, Paul; Reucroft, Stephen; Swain, John; Trummer, Julia

    2007-01-01

    We have studied the performance of two multi-pixel Geiger-mode APDs (recently developed by the Centre of Perspective Technologies and Apparatus (CPTA) in Moscow) with 1×1 mm2 and 3×3 mm2 sensitive area as a readout for LSO and LYSO scintillator crystals. Energy and timing spectra were measured using a 22Na γ-source. The results of this study allow us to conclude that this photodetector is a very promising candidate for PET applications.

  14. Performance of hybrid photon detector prototypes with 80% active area for the rich counters of LHCB

    International Nuclear Information System (INIS)

    Albrecht, E.; Alemi, M.; Barber, G.; Bibby, J.; Campbell, M.; Duane, A.; Gys, T.; Montenegro, J.; Piedigrossi, D.; Schomaker, R.; Snoeys, W.; Wotton, S.; Wyllie, K.

    2000-01-01

    We report on the ongoing work towards a hybrid photon detector with integrated silicon pixel readout for the ring imaging Cherenkov detectors of the LHCb experiment at the Large Hadron Collider at CERN. The photon detector is based on an electrostatically focussed image intensifier tube geometry where the image is de-magnified by a factor of ∼5. The anode consists of a silicon pixel array, bump-bonded to a binary readout chip with matching pixel electronics. The performance of full-scale prototypes equipped with 61-pixel anodes and external analogue readout is presented. The average signal-to-noise ratio is ∼11 with a peaking time of 1.2 μs. The tube active-to-total surface ratio is 81.7%, which meets the LHCb requirements. The spatial precision is measured to be better than 90 μm. A cluster of three such tubes has been installed in the LHCb RICH 1 prototype where Cherenkov gas rings have been successfully detected. Progress towards the encapsulation of new pixel electronics into a tube is also reported. In particular, the status of the development of a binary readout chip with a peaking time of 25 ns and a low and uniform detection threshold is summarized

  15. Performance of hybrid photon detector prototypes with 80% active area for the rich counters of LHCB

    Energy Technology Data Exchange (ETDEWEB)

    Albrecht, E.; Alemi, M.; Barber, G.; Bibby, J.; Campbell, M.; Duane, A.; Gys, T. E-mail: thierry.gys@cern.ch; Montenegro, J.; Piedigrossi, D.; Schomaker, R.; Snoeys, W.; Wotton, S.; Wyllie, K

    2000-03-11

    We report on the ongoing work towards a hybrid photon detector with integrated silicon pixel readout for the ring imaging Cherenkov detectors of the LHCb experiment at the Large Hadron Collider at CERN. The photon detector is based on an electrostatically focussed image intensifier tube geometry where the image is de-magnified by a factor of {approx}5. The anode consists of a silicon pixel array, bump-bonded to a binary readout chip with matching pixel electronics. The performance of full-scale prototypes equipped with 61-pixel anodes and external analogue readout is presented. The average signal-to-noise ratio is {approx}11 with a peaking time of 1.2 {mu}s. The tube active-to-total surface ratio is 81.7%, which meets the LHCb requirements. The spatial precision is measured to be better than 90 {mu}m. A cluster of three such tubes has been installed in the LHCb RICH 1 prototype where Cherenkov gas rings have been successfully detected. Progress towards the encapsulation of new pixel electronics into a tube is also reported. In particular, the status of the development of a binary readout chip with a peaking time of 25 ns and a low and uniform detection threshold is summarized.

  16. Feasibility study of multi-pixel retrieval of optical thickness and droplet effective radius of inhomogeneous clouds using deep learning

    Science.gov (United States)

    Okamura, Rintaro; Iwabuchi, Hironobu; Schmidt, K. Sebastian

    2017-12-01

    Three-dimensional (3-D) radiative-transfer effects are a major source of retrieval errors in satellite-based optical remote sensing of clouds. The challenge is that 3-D effects manifest themselves across multiple satellite pixels, which traditional single-pixel approaches cannot capture. In this study, we present two multi-pixel retrieval approaches based on deep learning, a technique that is becoming increasingly successful for complex problems in engineering and other areas. Specifically, we use deep neural networks (DNNs) to obtain multi-pixel estimates of cloud optical thickness and column-mean cloud droplet effective radius from multispectral, multi-pixel radiances. The first DNN method corrects traditional bispectral retrievals based on the plane-parallel homogeneous cloud assumption using the reflectances at the same two wavelengths. The other DNN method uses so-called convolutional layers and retrieves cloud properties directly from the reflectances at four wavelengths. The DNN methods are trained and tested on cloud fields from large-eddy simulations used as input to a 3-D radiative-transfer model to simulate upward radiances. The second DNN-based retrieval, sidestepping the bispectral retrieval step through convolutional layers, is shown to be more accurate. It reduces 3-D radiative-transfer effects that would otherwise affect the radiance values and estimates cloud properties robustly even for optically thick clouds.

  17. Limits on Achievable Dimensional and Photon Efficiencies with Intensity-Modulation and Photon-Counting Due to Non-Ideal Photon-Counter Behavior

    Science.gov (United States)

    Moision, Bruce; Erkmen, Baris I.; Farr, William; Dolinar, Samuel J.; Birnbaum, Kevin M.

    2012-01-01

    An ideal intensity-modulated photon-counting channel can achieve unbounded photon information efficiencies (PIEs). However, a number of limitations of a physical system limit the practically achievable PIE. In this paper, we discuss several of these limitations and illustrate their impact on the channel. We show that, for the Poisson channel, noise does not strictly bound PIE, although there is an effective limit, as the dimensional information efficiency goes as e[overline] e PIE beyond a threshold PIE. Since the Holevo limit is bounded in the presence of noise, this illustrates that the Poisson approximation is invalid at large PIE for any number of noise modes. We show that a finite transmitter extinction ratio bounds the achievable PIE to a maximum that is logarithmic in the extinction ratio. We show how detector jitter limits the ability to mitigate noise in the PPM signaling framework. We illustrate a method to model detector blocking when the number of detectors is large, and illustrate mitigation of blocking with spatial spreading and altering. Finally, we illustrate the design of a high photon efficiency system using state-of-the-art photo-detectors and taking all these effects into account.

  18. Experimental characterization of the 192 channel Clear-PEM frontend ASIC coupled to a multi-pixel APD readout of LYSO:Ce crystals

    International Nuclear Information System (INIS)

    Albuquerque, Edgar; Bexiga, Vasco; Bugalho, Ricardo; Carrico, Bruno; Ferreira, Claudia S.; Ferreira, Miguel; Godinho, Joaquim; Goncalves, Fernando; Leong, Carlos; Lousa, Pedro; Machado, Pedro; Moura, Rui; Neves, Pedro; Ortigao, Catarina; Piedade, Fernando; Pinheiro, Joao F.; Rego, Joel; Rivetti, Angelo; Rodrigues, Pedro; Silva, Jose C.

    2009-01-01

    In the framework of the Clear-PEM project for the construction of a high-resolution scanner for breast cancer imaging, a very compact and dense frontend electronics system has been developed for readout of multi-pixel S8550 Hamamatsu APDs. The frontend electronics are instrumented with a mixed-signal Application-Specific Integrated Circuit (ASIC), which incorporates 192 low-noise charge pre-amplifiers, shapers, analog memory cells and digital control blocks. Pulses are continuously stored in memory cells at clock frequency. Channels above a common threshold voltage are readout for digitization by off-chip free-sampling ADCs. The ASIC has a size of 7.3x9.8mm 2 and was implemented in a AMS 0.35μm CMOS technology. In this paper the experimental characterization of the Clear-PEM frontend ASIC, reading out multi-pixel APDs coupled to LYSO:Ce crystal matrices, is presented. The chips were mounted on a custom test board connected to six APD arrays and to the data acquisition system. Six 32-pixel LYSO:Ce crystal matrices coupled on both sides to APD arrays were readout by two test boards. All 384 channels were operational. The chip power consumption is 660 mW (3.4 mW per channel). A very stable behavior of the chip was observed, with an estimated ENC of 1200-1300e - at APD gain 100. The inter-channel noise dispersion and mean baseline variation is less than 8% and 0.5%, respectively. The spread in the gain between different channels is found to be 1.5%. Energy resolution of 16.5% at 511 keV and 12.8% at 662 keV has been measured. Timing measurements between the two APDs that readout the same crystal is extracted and compared with detailed Monte Carlo simulations. At 511 keV the measured single photon time RMS resolution is 1.30 ns, in very good agreement with the expected value of 1.34 ns.

  19. Volumetric CT with sparse detector arrays (and application to Si-strip photon counters).

    Science.gov (United States)

    Sisniega, A; Zbijewski, W; Stayman, J W; Xu, J; Taguchi, K; Fredenberg, E; Lundqvist, Mats; Siewerdsen, J H

    2016-01-07

    Novel x-ray medical imaging sensors, such as photon counting detectors (PCDs) and large area CCD and CMOS cameras can involve irregular and/or sparse sampling of the detector plane. Application of such detectors to CT involves undersampling that is markedly different from the commonly considered case of sparse angular sampling. This work investigates volumetric sampling in CT systems incorporating sparsely sampled detectors with axial and helical scan orbits and evaluates performance of model-based image reconstruction (MBIR) with spatially varying regularization in mitigating artifacts due to sparse detector sampling. Volumetric metrics of sampling density and uniformity were introduced. Penalized-likelihood MBIR with a spatially varying penalty that homogenized resolution by accounting for variations in local sampling density (i.e. detector gaps) was evaluated. The proposed methodology was tested in simulations and on an imaging bench based on a Si-strip PCD (total area 5 cm  ×  25 cm) consisting of an arrangement of line sensors separated by gaps of up to 2.5 mm. The bench was equipped with translation/rotation stages allowing a variety of scanning trajectories, ranging from a simple axial acquisition to helical scans with variable pitch. Statistical (spherical clutter) and anthropomorphic (hand) phantoms were considered. Image quality was compared to that obtained with a conventional uniform penalty in terms of structural similarity index (SSIM), image uniformity, spatial resolution, contrast, and noise. Scan trajectories with intermediate helical width (~10 mm longitudinal distance per 360° rotation) demonstrated optimal tradeoff between the average sampling density and the homogeneity of sampling throughout the volume. For a scan trajectory with 10.8 mm helical width, the spatially varying penalty resulted in significant visual reduction of sampling artifacts, confirmed by a 10% reduction in minimum SSIM (from 0.88 to 0.8) and a 40

  20. 3D Cloud Tomography, Followed by Mean Optical and Microphysical Properties, with Multi-Angle/Multi-Pixel Data

    Science.gov (United States)

    Davis, A. B.; von Allmen, P. A.; Marshak, A.; Bal, G.

    2010-12-01

    The geometrical assumption in all operational cloud remote sensing algorithms is that clouds are plane-parallel slabs, which applies relatively well to the most uniform stratus layers. Its benefit is to justify using classic 1D radiative transfer (RT) theory, where angular details (solar, viewing, azimuthal) are fully accounted for and precise phase functions can be used, to generate the look-up tables used in the retrievals. Unsurprisingly, these algorithms catastrophically fail when applied to cumulus-type clouds, which are highly 3D. This is unfortunate for the cloud-process modeling community that may thrive on in situ airborne data, but would very much like to use satellite data for more than illustrations in their presentations and publications. So, how can we obtain quantitative information from space-based observations of finite aspect ratio clouds? Cloud base/top heights, vertically projected area, mean liquid water content (LWC), and volume-averaged droplet size would be a good start. Motivated by this science need, we present a new approach suitable for sparse cumulus fields where we turn the tables on the standard procedure in cloud remote sensing. We make no a priori assumption about cloud shape, save an approximately flat base, but use brutal approximations about the RT that is necessarily 3D. Indeed, the first order of business is to roughly determine the cloud's outer shape in one of two ways, which we will frame as competing initial guesses for the next phase of shape refinement and volume-averaged microphysical parameter estimation. Both steps use multi-pixel/multi-angle techniques amenable to MISR data, the latter adding a bi-spectral dimension using collocated MODIS data. One approach to rough cloud shape determination is to fit the multi-pixel/multi-angle data with a geometric primitive such as a scalene hemi-ellipsoid with 7 parameters (translation in 3D space, 3 semi-axes, 1 azimuthal orientation); for the radiometry, a simple radiosity

  1. Note: Large active area solid state photon counter with 20 ps timing resolution and 60 fs detection delay stability

    Science.gov (United States)

    Prochazka, Ivan; Kodet, Jan; Eckl, Johann; Blazej, Josef

    2017-10-01

    We are reporting on the design, construction, and performance of a photon counting detector system, which is based on single photon avalanche diode detector technology. This photon counting device has been optimized for very high timing resolution and stability of its detection delay. The foreseen application of this detector is laser ranging of space objects, laser time transfer ground to space and fundamental metrology. The single photon avalanche diode structure, manufactured on silicon using K14 technology, is used as a sensor. The active area of the sensor is circular with 200 μm diameter. Its photon detection probability exceeds 40% in the wavelength range spanning from 500 to 800 nm. The sensor is operated in active quenching and gating mode. A new control circuit was optimized to maintain high timing resolution and detection delay stability. In connection to this circuit, timing resolution of the detector is reaching 20 ps FWHM. In addition, the temperature change of the detection delay is as low as 70 fs/K. As a result, the detection delay stability of the device is exceptional: expressed in the form of time deviation, detection delay stability of better than 60 fs has been achieved. Considering the large active area aperture of the detector, this is, to our knowledge, the best timing performance reported for a solid state photon counting detector so far.

  2. Photonics

    CERN Document Server

    Andrews, David L

    2015-01-01

    Discusses the basic physical principles underlying Biomedical Photonics, spectroscopy and microscopy This volume discusses biomedical photonics, spectroscopy and microscopy, the basic physical principles underlying the technology and its applications. The topics discussed in this volume are: Biophotonics; Fluorescence and Phosphorescence; Medical Photonics; Microscopy; Nonlinear Optics; Ophthalmic Technology; Optical Tomography; Optofluidics; Photodynamic Therapy; Image Processing; Imaging Systems; Sensors; Single Molecule Detection; Futurology in Photonics. Comprehensive and accessible cov

  3. Photonics

    CERN Document Server

    Andrews, David L

    2015-01-01

    Discusses the basic physical principles underlying the technology instrumentation of photonics This volume discusses photonics technology and instrumentation. The topics discussed in this volume are: Communication Networks; Data Buffers; Defense and Security Applications; Detectors; Fiber Optics and Amplifiers; Green Photonics; Instrumentation and Metrology; Interferometers; Light-Harvesting Materials; Logic Devices; Optical Communications; Remote Sensing; Solar Energy; Solid-State Lighting; Wavelength Conversion Comprehensive and accessible coverage of the whole of modern photonics Emphas

  4. Photonics

    CERN Document Server

    Andrews, David L

    2015-01-01

    Discusses the basic physical principles underlying thescience and technology of nanophotonics, its materials andstructures This volume presents nanophotonic structures and Materials.Nanophotonics is photonic science and technology that utilizeslight/matter interactions on the nanoscale where researchers arediscovering new phenomena and developing techniques that go wellbeyond what is possible with conventional photonics andelectronics.The topics discussed in this volume are: CavityPhotonics; Cold Atoms and Bose-Einstein Condensates; Displays;E-paper; Graphene; Integrated Photonics; Liquid Cry

  5. Photonics

    CERN Document Server

    Andrews, David L

    2015-01-01

    This book covers modern photonics accessibly and discusses the basic physical principles underlying all the applications and technology of photonicsThis volume covers the basic physical principles underlying the technology and all applications of photonics from statistical optics to quantum optics. The topics discussed in this volume are: Photons in perspective; Coherence and Statistical Optics; Complex Light and Singular Optics; Electrodynamics of Dielectric Media; Fast and slow Light; Holography; Multiphoton Processes; Optical Angular Momentum; Optical Forces, Trapping and Manipulation; Pol

  6. Performance of hybrid photon detector prototypes with encapsulated silicon pixel detector and readout for the RICH counters of LHCb

    International Nuclear Information System (INIS)

    Campbell, M.; George, K.A.; Girone, M.; Gys, T.; Jolly, S.; Piedigrossi, D.; Riedler, P.; Rozema, P.; Snoeys, W.; Wyllie, K.

    2003-01-01

    These proceedings report on the performance of the latest prototype pixel hybrid photon detector in preparation for the LHCb Ring Imaging Cherenkov detectors. The prototype encapsulates a silicon pixel detector bump-bonded to a binary read-out chip with short (25 ns) peaking time and low ( - ) detection threshold. A brief description of the prototype is given, followed by the preliminary results of the characterisation of the prototype behaviour when tested using a low intensity pulsed light emitting diode. The results obtained are in good agreement with those obtained using previous prototypes. The proceedings conclude with a summary of the current status and future plans

  7. Development of a cylindrical tracking detector with multichannel scintillation fibers and pixelated photon detector readout

    Energy Technology Data Exchange (ETDEWEB)

    Akazawa, Y.; Miwa, K.; Honda, R.; Shiozaki, T.; Chiga, N.

    2015-07-01

    We are developing a cylindrical tracking detector for a Σp scattering experiment in J-PARC with scintillation fibers and the Pixelated Photon Detector (PPD) readout, which is called as cylindrical fiber tracker (CFT), in order to reconstruct trajectories of charged particles emitted inside CFT. CFT works not only as a tracking detector but also a particle identification detector from energy deposits. A prototype CFT consisting of two straight layers and one spiral layer was constructed. About 1100 scintillation fibers with a diameter of 0.75 mm (Kuraray SCSF-78 M) were used. Each fiber signal was read by Multi-Pixel Photon Counter (MPPC, HPK S10362-11-050P, 1×1 mm{sup 2}, 400 pixels) fiber by fiber. MPPCs were handled with Extended Analogue Silicon Photomultipliers Integrated ReadOut Chip (EASIROC) boards, which were developed for the readout of a large number of MPPCs. The energy resolution of one layer was 28% for a 70 MeV proton where the energy deposit in fibers was 0.7 MeV.

  8. Needle counter

    International Nuclear Information System (INIS)

    Fujita, Yuzo

    1977-01-01

    Needle counter had been devised by Geiger about 60 years ago before the present GM counter appeared. It is suitable for the detection of weak radiation because it is limited in effective volume, if the background due to mainly cosmic ray is proportional to the effective volume of the counter. Recently the very low β detector having a needle counter as the main detector has been developed. It showed highly excellent performance in the measurements of small area samples, about ten times sensitive as compared with other detectors. The counter is installed in the very low radiation measuring well at Nokogiriyama, Chiba Prefecture, using a NaI scintillator as its guard counter. D. H. Wilkinson first treated a gas amplification counter theoretically and quantitatively. The authors have obtained good results in the comparison with the experiments of the counter using a generalized form of Wilkinson theory. The findings obtained through this study seem to be applicable to the electrode arrangement which is important for the counter design. It was found that the excellent rise time of induced pulses in a gas amplification counter was achieved in larger amplification factor and smaller convolution effect. In the detection of charged particles with small obstructing capability such as γ ray, faster rise time and higher pulses can be obtained with needle counters than wire counters. (Wakatsuki, Y.)

  9. Time-resolved imaging of prompt-gamma rays for proton range verification using a knife-edge slit camera based on digital photon counters

    Science.gov (United States)

    Cambraia Lopes, Patricia; Clementel, Enrico; Crespo, Paulo; Henrotin, Sebastien; Huizenga, Jan; Janssens, Guillaume; Parodi, Katia; Prieels, Damien; Roellinghoff, Frauke; Smeets, Julien; Stichelbaut, Frederic; Schaart, Dennis R.

    2015-08-01

    Proton range monitoring may facilitate online adaptive proton therapy and improve treatment outcomes. Imaging of proton-induced prompt gamma (PG) rays using a knife-edge slit collimator is currently under investigation as a potential tool for real-time proton range monitoring. A major challenge in collimated PG imaging is the suppression of neutron-induced background counts. In this work, we present an initial performance test of two knife-edge slit camera prototypes based on arrays of digital photon counters (DPCs). PG profiles emitted from a PMMA target upon irradiation with a 160 MeV proton pencil beams (about 6.5   ×   109 protons delivered in total) were measured using detector modules equipped with four DPC arrays coupled to BGO or LYSO : Ce crystal matrices. The knife-edge slit collimator and detector module were placed at 15 cm and 30 cm from the beam axis, respectively, in all cases. The use of LYSO : Ce enabled time-of-flight (TOF) rejection of background events, by synchronizing the DPC readout electronics with the 106 MHz radiofrequency signal of the cyclotron. The signal-to-background (S/B) ratio of 1.6 obtained with a 1.5 ns TOF window and a 3 MeV-7 MeV energy window was about 3 times higher than that obtained with the same detector module without TOF discrimination and 2 times higher than the S/B ratio obtained with the BGO module. Even 1 mm shifts of the Bragg peak position translated into clear and consistent shifts of the PG profile if TOF discrimination was applied, for a total number of protons as low as about 6.5   ×   108 and a detector surface of 6.6 cm  ×  6.6 cm.

  10. Adjoint Methods for Adjusting Three-Dimensional Atmosphere and Surface Properties to Fit Multi-Angle Multi-Pixel Polarimetric Measurements

    Science.gov (United States)

    Martin, William G.; Cairns, Brian; Bal, Guillaume

    2014-01-01

    This paper derives an efficient procedure for using the three-dimensional (3D) vector radiative transfer equation (VRTE) to adjust atmosphere and surface properties and improve their fit with multi-angle/multi-pixel radiometric and polarimetric measurements of scattered sunlight. The proposed adjoint method uses the 3D VRTE to compute the measurement misfit function and the adjoint 3D VRTE to compute its gradient with respect to all unknown parameters. In the remote sensing problems of interest, the scalar-valued misfit function quantifies agreement with data as a function of atmosphere and surface properties, and its gradient guides the search through this parameter space. Remote sensing of the atmosphere and surface in a three-dimensional region may require thousands of unknown parameters and millions of data points. Many approaches would require calls to the 3D VRTE solver in proportion to the number of unknown parameters or measurements. To avoid this issue of scale, we focus on computing the gradient of the misfit function as an alternative to the Jacobian of the measurement operator. The resulting adjoint method provides a way to adjust 3D atmosphere and surface properties with only two calls to the 3D VRTE solver for each spectral channel, regardless of the number of retrieval parameters, measurement view angles or pixels. This gives a procedure for adjusting atmosphere and surface parameters that will scale to the large problems of 3D remote sensing. For certain types of multi-angle/multi-pixel polarimetric measurements, this encourages the development of a new class of three-dimensional retrieval algorithms with more flexible parametrizations of spatial heterogeneity, less reliance on data screening procedures, and improved coverage in terms of the resolved physical processes in the Earth?s atmosphere.

  11. A fast photo-counter with multi-level buffers

    International Nuclear Information System (INIS)

    Peng Hu; Zhou Peiling; Yao Kun; Guo Guangcan

    1992-01-01

    Digital Photon Correlator (DPC) is composed of a Photo-counter and a data processing unit. The performance of Photo-counter in data acquisition system has a direct influence on data processing. The Photo-counter with fast carry designed here has multi-level buffers. Photon pulses can be correctly and dynamically recorded by the Photo-counter and processed by a single chip computer

  12. Adaptation of an aerosol retrieval algorithm using multi-wavelength and multi-pixel information of satellites (MWPM) to GOSAT/TANSO-CAI

    Science.gov (United States)

    Hashimoto, M.; Takenaka, H.; Higurashi, A.; Nakajima, T.

    2017-12-01

    Aerosol in the atmosphere is an important constituent for determining the earth's radiation budget, so the accurate aerosol retrievals from satellite is useful. We have developed a satellite remote sensing algorithm to retrieve the aerosol optical properties using multi-wavelength and multi-pixel information of satellite imagers (MWPM). The method simultaneously derives aerosol optical properties, such as aerosol optical thickness (AOT), single scattering albedo (SSA) and aerosol size information, by using spatial difference of wavelegths (multi-wavelength) and surface reflectances (multi-pixel). The method is useful for aerosol retrieval over spatially heterogeneous surface like an urban region. In this algorithm, the inversion method is a combination of an optimal method and smoothing constraint for the state vector. Furthermore, this method has been combined with the direct radiation transfer calculation (RTM) numerically solved by each iteration step of the non-linear inverse problem, without using look up table (LUT) with several constraints. However, it takes too much computation time. To accelerate the calculation time, we replaced the RTM with an accelerated RTM solver learned by neural network-based method, EXAM (Takenaka et al., 2011), using Rster code. And then, the calculation time was shorternd to about one thouthandth. We applyed MWPM combined with EXAM to GOSAT/TANSO-CAI (Cloud and Aerosol Imager). CAI is a supplement sensor of TANSO-FTS, dedicated to measure cloud and aerosol properties. CAI has four bands, 380, 674, 870 and 1600 nm, and observes in 500 meters resolution for band1, band2 and band3, and 1.5 km for band4. Retrieved parameters are aerosol optical properties, such as aerosol optical thickness (AOT) of fine and coarse mode particles at a wavelenth of 500nm, a volume soot fraction in fine mode particles, and ground surface albedo of each observed wavelength by combining a minimum reflectance method and Fukuda et al. (2013). We will show

  13. Real-time imaging systems for superconducting nanowire single-photon detector arrays

    Energy Technology Data Exchange (ETDEWEB)

    Hofherr, Matthias

    2014-07-01

    Superconducting nanowire singe-photon detectors (SNSPD) are promising detectors in the field of applications, where single-photon resolution is required like in quantum optics, spectroscopy or astronomy. These cryogenic detectors gain from a broad spectrum in the optical and infrared range and deliver low dark counts and low jitter. This work provides a piece of deeper physical understanding of detector functionality in combination with highly engineered readout development. A detailed analysis focuses on the intrinsic detection mechanism of SNSPDs related to the detection in the infrared regime and the evolution of dark counts. With this fundamental knowledge, the next step is the development of a multi-pixel readout at cryogenic conditions. It is demonstrated, how two auspicious multi-pixel readout concepts can be realized, which enables statistical framing like in imaging applications using RSFQ electronics with fast framing rates and the readout of a detector array with continuous real-time single-photon resolution.

  14. Silicon photomultipliers in AMIGA muon counters

    Energy Technology Data Exchange (ETDEWEB)

    Botti, Ana Martina [Institut fuer Kernphysik, Karlsruher Institut fuer Technologie (Germany); Instituto de Tecnologias en Deteccion y Astroparticulas (ITeDA) (Argentina); Collaboration: Pierre-Auger-Collaboration

    2016-07-01

    The project AMIGA (Auger Muons and Infill for the Ground Array) aims to extend the energy range at the Pierre Auger Observatory to observe cosmic rays of lower energies (down to ∝10{sup 17} eV) and to study the transition from extragalactic to galactic cosmic rays. AMIGA is compounded by an infill of surface detectors (employing Cherenkov radiation detection in water) and muon counters. The AMIGA muon counters consist of an array of buried modules composed of 64 scintillator bars, a multi-pixel Photo Multiplier Tube (PMT) and the corresponding electronic of acquisition which works along with the surface detector. Currently, ITeDA is evaluating the feasibility of replacing PMTs with silicon photomultipliers (SiPM) without performing any substantial modification in the digital readout nor in the mechanical design. I present calibration results of a prototype module associated to the surface detector Toune of the Pierre Auger Observatory using a SiPM Hamamatsu S1257-100C plugged to the standard AMIGA front-end electronics. In addition, a study concerning gain stability and temperature variation has also been performed and is reported. I finally discuss a comparison between traces measured by both photodetectors (PMT and SiPM) for modules associated to the surface detector Toune.

  15. Four-layer depth-of-interaction PET detector for high resolution PET using a multi-pixel S8550 avalanche photodiode

    International Nuclear Information System (INIS)

    Nishikido, Fumihiko; Inadama, Naoko; Oda, Ichiro; Shibuya, Kengo; Yoshida, Eiji; Yamaya, Taiga; Kitamura, Keishi; Murayama, Hideo

    2010-01-01

    Avalanche photodiodes (APDs) are being used as photodetectors in positron emission tomography (PET) because they have many advantages over photomultipliers (PMTs) typically used in PET detectors. We have developed a PET detector that consists of a multi-pixel APD and a 6x6x4 array of 1.46x1.46 mm 2 x4.5 m LYSO crystals for a small animal PET scanner. The detector can identify four-layer depth of interaction (DOI) with a position-sensitive APD coupled to the backside of a crystal array by just an optimized reflector arrangement. Since scintillation lights are shared among many pixels by the method, weaker signals in APD pixels far from the interacting crystals are affected by noise. To evaluate the performance of the four-layer DOI detector with the APD and the influence of electrical noise on our method, we constructed a prototype DOI detector and tested its performance. We found, except for crystal elements on the edge of the crystal array, all crystal elements could be identified from the 2D position histogram. An energy resolution of 16.9% was obtained for the whole crystal array of the APD detector. The results of noise dependence of detector performances indicated that the DOI detector using the APD could achieve sufficient performance even when using application-specific integrated circuits.

  16. Four-layer depth-of-interaction PET detector for high resolution PET using a multi-pixel S8550 avalanche photodiode

    Energy Technology Data Exchange (ETDEWEB)

    Nishikido, Fumihiko, E-mail: funis@nirs.go.j [Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Inadama, Naoko [Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Oda, Ichiro [Shimadzu Corporation, Nishinokyo Kuwabaracho 1 Nakagyo-ku, Kyoto-shi, Kyoto 604-8511 (Japan); Shibuya, Kengo; Yoshida, Eiji; Yamaya, Taiga [Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Kitamura, Keishi [Shimadzu Corporation, Nishinokyo Kuwabaracho 1 Nakagyo-ku, Kyoto-shi, Kyoto 604-8511 (Japan); Murayama, Hideo [Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan)

    2010-09-21

    Avalanche photodiodes (APDs) are being used as photodetectors in positron emission tomography (PET) because they have many advantages over photomultipliers (PMTs) typically used in PET detectors. We have developed a PET detector that consists of a multi-pixel APD and a 6x6x4 array of 1.46x1.46 mm{sup 2}x4.5 m LYSO crystals for a small animal PET scanner. The detector can identify four-layer depth of interaction (DOI) with a position-sensitive APD coupled to the backside of a crystal array by just an optimized reflector arrangement. Since scintillation lights are shared among many pixels by the method, weaker signals in APD pixels far from the interacting crystals are affected by noise. To evaluate the performance of the four-layer DOI detector with the APD and the influence of electrical noise on our method, we constructed a prototype DOI detector and tested its performance. We found, except for crystal elements on the edge of the crystal array, all crystal elements could be identified from the 2D position histogram. An energy resolution of 16.9% was obtained for the whole crystal array of the APD detector. The results of noise dependence of detector performances indicated that the DOI detector using the APD could achieve sufficient performance even when using application-specific integrated circuits.

  17. Development of photocathodes for gas counters

    International Nuclear Information System (INIS)

    Chalot, J.F.

    1982-03-01

    A lot of ways of physics needs the development of high sensibility imaging devices with large sensitive surface. The problems brought by the building of such devices may be solved by the use of gaz counters. But we must sensitize these counters to low energy photons ( [fr

  18. Electromagnetic shower counter

    CERN Multimedia

    CERN PhotoLab

    1974-01-01

    The octogonal block of lead glass is observed by eight photomultiplier tubes. Four or five such counters, arranged in succession, are used on each arm of the bispectrometer in order to detect heavy particles of the same family as those recently observed at Brookhaven and SLAC. They provide a means of identifying electrons. The arrangement of eight lateral photomultiplier tubes offers an efficient means of collecting the photons produced in the showers and determining, with a high resolution, the energy of the incident electrons. The total width at half-height is less than 6.9% for electrons having an energy of 1 GeV.

  19. Generation of photon number states

    International Nuclear Information System (INIS)

    Waks, Edo; Diamanti, Eleni; Yamamoto, Yoshihisa

    2006-01-01

    The visible light photon counter (VLPC) has the capability to discriminate photon number states, in contrast to conventional photon counters which can only detect the presence or absence of photons. We use this capability, along with the process of parametric down-conversion, to generate photon number states. We experimentally demonstrate generation of states containing 1, 2, 3 and 4 photons with high fidelity. We then explore the effect the detection efficiency of the VLPC has on the generation rate and fidelity of the created states

  20. The Physics of Imaging with Remote Sensors : Photon State Space & Radiative Transfer

    Science.gov (United States)

    Davis, Anthony B.

    2012-01-01

    Standard (mono-pixel/steady-source) retrieval methodology is reaching its fundamental limit with access to multi-angle/multi-spectral photo- polarimetry. Next... Two emerging new classes of retrieval algorithm worth nurturing: multi-pixel time-domain Wave-radiometry transition regimes, and more... Cross-fertilization with bio-medical imaging. Physics-based remote sensing: - What is "photon state space?" - What is "radiative transfer?" - Is "the end" in sight? Two wide-open frontiers! center dot Examples (with variations.

  1. Body counter

    International Nuclear Information System (INIS)

    Koeppe, P.

    1975-01-01

    The paper gives a survey on some applications of the whole body counter in clinical practice and a critical study of its application as a routine testing method. Remarks on the necessary precautions are followed by a more detailed discussion of the determination of the natural potassium content, the iron metabolism, the vitamin B12 test, investigations of the metabolism of the bone using 47 Ca and 85 Sr, investigations with iodine and iodine-labelled substances, clearance investigations (in particular the 51 Cr EDTA clearance test), as well as the possibilities of neutron activation in vivo. (ORU/AK) [de

  2. Scintillation counter, segmented shield

    International Nuclear Information System (INIS)

    Olson, R.E.; Thumim, A.D.

    1975-01-01

    A scintillation counter, particularly for counting gamma ray photons, includes a massive lead radiation shield surrounding a sample-receiving zone. The shield is disassembleable into a plurality of segments to allow facile installation and removal of a photomultiplier tube assembly, the segments being so constructed as to prevent straight-line access of external radiation through the shield into radiation-responsive areas. Provisions are made for accurately aligning the photomultiplier tube with respect to one or more sample-transmitting bores extending through the shield to the sample receiving zone. A sample elevator, used in transporting samples into the zone, is designed to provide a maximum gamma-receiving aspect to maximize the gamma detecting efficiency. (U.S.)

  3. Performance of the latest MPPCs with reduced dark counts and improved photon detection efficiency

    International Nuclear Information System (INIS)

    Tsujikawa, T.; Funamoto, H.; Kataoka, J.; Fujita, T.; Nishiyama, T.; Kurei, Y.; Sato, K.; Yamamura, K.; Nakamura, S.

    2014-01-01

    We have tested the performance of two types of the latest Multi-Pixel Photon Counters (MPPCs; measuring 3×3 mm 2 in size) developed by Hamamatsu Photonics K.K. The new S12572-050C is a successor to the S10362-33-050C (i.e., conventional 3×3-mm 2 pixel MPPC of 50 μm pitch), comprises 3600 Geiger mode avalanche photodiodes (APDs), and also features high gain (up to 1.25×10 6 ), a low dark count (up to 10 6 cps), and improved photon detection efficiency (PDE) by up to 30%. The S12572-015C is a new type of fine-pitch (15 μm) MPPC featuring a wide dynamic range and fast timing response. This paper first presents the detailed performance of these latest MPPCs as photon counting devices. It then describes our fabrication of a prototype detector consisting of a MPPC optically coupled with a Ce:GAGG scintillator. We obtained average FWHM energy resolutions of 7.3% (15 μm) and 6.7% (new-50 μm), as compared to 6.9% (old-50 μm) for 662-keV gamma rays from the 137 Cs source, as measured at 20 °C. Moreover, the number of fired pixels for 662-keV gamma rays increased by 30% for the new-50 μm (as compared to the old-50 μm). We confirmed that the low energy threshold improved from 10 keV to 4 keV, when using the latest MPPC device (new-50 μm). We also confirmed that the timing resolution of the new MPPC is 50 ps or even better, as compared to 89 ps of the old MPPC. The results thus confirm that these new types of MPPCs are promising for various applications as scintillation detectors. - Highlights: • We tested the performance of the latest MPPC. • We confirmed that the new MPPC is superior to the old MPPC. • We plan to apply the new MPPC for a next-generation PET and a handy Compton camera

  4. Performance of the latest MPPCs with reduced dark counts and improved photon detection efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Tsujikawa, T., E-mail: takayuki-t.w@asagi.waseda.jp [Research Institute for Science and Engineering, Waseda University, 3-4-1, Ohkubo, Shinjuku, Tokyo (Japan); Funamoto, H.; Kataoka, J.; Fujita, T.; Nishiyama, T.; Kurei, Y. [Research Institute for Science and Engineering, Waseda University, 3-4-1, Ohkubo, Shinjuku, Tokyo (Japan); Sato, K.; Yamamura, K.; Nakamura, S. [Solid State Division, Hamamatsu Photonics K. K., 1126-1, Ichino-cho, Hamamatsu, Shizuoka (Japan)

    2014-11-21

    We have tested the performance of two types of the latest Multi-Pixel Photon Counters (MPPCs; measuring 3×3 mm{sup 2} in size) developed by Hamamatsu Photonics K.K. The new S12572-050C is a successor to the S10362-33-050C (i.e., conventional 3×3-mm{sup 2} pixel MPPC of 50 μm pitch), comprises 3600 Geiger mode avalanche photodiodes (APDs), and also features high gain (up to 1.25×10{sup 6}), a low dark count (up to 10{sup 6} cps), and improved photon detection efficiency (PDE) by up to 30%. The S12572-015C is a new type of fine-pitch (15 μm) MPPC featuring a wide dynamic range and fast timing response. This paper first presents the detailed performance of these latest MPPCs as photon counting devices. It then describes our fabrication of a prototype detector consisting of a MPPC optically coupled with a Ce:GAGG scintillator. We obtained average FWHM energy resolutions of 7.3% (15 μm) and 6.7% (new-50 μm), as compared to 6.9% (old-50 μm) for 662-keV gamma rays from the {sup 137}Cs source, as measured at 20 °C. Moreover, the number of fired pixels for 662-keV gamma rays increased by 30% for the new-50 μm (as compared to the old-50 μm). We confirmed that the low energy threshold improved from 10 keV to 4 keV, when using the latest MPPC device (new-50 μm). We also confirmed that the timing resolution of the new MPPC is 50 ps or even better, as compared to 89 ps of the old MPPC. The results thus confirm that these new types of MPPCs are promising for various applications as scintillation detectors. - Highlights: • We tested the performance of the latest MPPC. • We confirmed that the new MPPC is superior to the old MPPC. • We plan to apply the new MPPC for a next-generation PET and a handy Compton camera.

  5. Almost real photons

    International Nuclear Information System (INIS)

    Fujii, H.

    1977-01-01

    High energy photon-proton scattering is expected to bring an important information on strong and electromagnetic interaction, and is discussed in this paper. When the ''mass'' of the photon is less than that of the lightest hadron, it is said ''the photon is almost real''. The photon energy is sufficiently high to check the energy dependence of the gamma-proton total cross section, even in the first stage of TRISTAN. The tagging system consists of four multi-wire proportional chambers (MWPC) and a lead glass Cerenkov counter. The energy of scattered electrons is determined with the Cerenkov counter. The equivalent-photon approximation is a useful method to obtain the counting rates. The estimation of the counting rate was made under the expected value of the total cross section. The estimated counting rate is strong enough for the experiment of the gamma-proton total cross section measurement. (Kato, T.)

  6. Distributed performance counters

    Science.gov (United States)

    Davis, Kristan D; Evans, Kahn C; Gara, Alan; Satterfield, David L

    2013-11-26

    A plurality of first performance counter modules is coupled to a plurality of processing cores. The plurality of first performance counter modules is operable to collect performance data associated with the plurality of processing cores respectively. A plurality of second performance counter modules are coupled to a plurality of L2 cache units, and the plurality of second performance counter modules are operable to collect performance data associated with the plurality of L2 cache units respectively. A central performance counter module may be operable to coordinate counter data from the plurality of first performance counter modules and the plurality of second performance modules, the a central performance counter module, the plurality of first performance counter modules, and the plurality of second performance counter modules connected by a daisy chain connection.

  7. Cerenkov counters at ISABELLE

    International Nuclear Information System (INIS)

    Etkin, A.; Kostoulas, I.; Leith, D.W.G.S.; Thun, R.

    1977-01-01

    The Cherenkov counter described for use at Isabelle is a threshold counter in which light is focussed on phototubes. The counter is applicable in large-angle, small-aperture magnetic spectrometers for measurement of particle yields at large p/sub T/. Three of these counters will provide complete π-K-p separation in the range of 7-20 GeV/c. Other Cherenkov counters are discussed and a bibliography of relevant literature on the counters utilizing photoionization is included

  8. CEDAR counter (internal part)

    CERN Multimedia

    CERN PhotoLab

    1976-01-01

    Here on the mounting bench. The counter is a differential Cerenkov, corrected for chromaticity, able to differentiate pions from kaons up to 350 GeV. Counters of this type were used in all SPS hadron beams.

  9. Whole Body Counters (rev.)

    Energy Technology Data Exchange (ETDEWEB)

    Woodburn, John H. [Walter Johnson High School, Rockville, MD; Lengemann, Frederick W. [Cornell University

    1967-01-01

    Whole body counters are radiation detecting and measuring instruments that provide information about the human body. This booklet describes different whole body counters, scientific principles that are applied to their design, and ways they are used.

  10. Multimode pulse counter

    International Nuclear Information System (INIS)

    Natanzon, D.D.

    1982-01-01

    A pulse counter with code conversion is described. The counter is based on the integrated circuits of direct-counting devices of medium integration. The counter ensures various modes of pulse counting depending on the logical control signals: reversible, two-channel summing, one-channel summing binary, summing with ''storage'' signal code fixation without interrupting pulse counting. Arrangement of the suggested structure as a microcircuit of medium integration might contribute to reduction in the counter type nomenclature in digital families of widely used integrated circuits

  11. Fast differential pulse discriminator-counter

    International Nuclear Information System (INIS)

    Shelevoj, K.D.

    1985-01-01

    The flowsheet of a differential pulse discriminator counter is described; the result of discrimination here is independent from the shape of the input pulse. Rate of the analysis of input pulses with minimum amplitude up to 0.3 mV coming out from the photomultiplier makes up 220 MHz. The flowsheet of the discriminator used in the system of photon counting for atmosphere probing is presented

  12. The first CEDAR counter

    CERN Multimedia

    CERN PhotoLab

    1976-01-01

    The first differential Cerenkov counter with chromatic corrections (called CEDAR) successfully tested at the PS in July 75. These counters were used in the SPS hadronic beams for particle identification. Some of the eight photomultipliers can be seen: they receive the light reflected back through the annular diaphragm. René Maleyran stands on the left.

  13. Scintillation counter: photomultiplier tube alignment

    International Nuclear Information System (INIS)

    Olson, R.E.

    1975-01-01

    A scintillation counter, particularly for counting gamma ray photons, includes a massive lead radiation shield surrounding a sample-receiving zone. The shield is disassembleable into a plurality of segments to allow facile installation and removal of a photomultiplier tube assembly, the segments being so constructed as to prevent straight-line access of external radiation through the shield into the sample receiving zone. Provisions are made for accurately aligning the photomultiplier tube with respect to one or more sample-transmitting bores extending through the shield to the sample receiving zone. A sample elevator, used in transporting samples into the zone, is designed to provide a maximum gamma-receiving aspect to maximize the gamma detecting efficiency. (auth)

  14. Scintillation counter, maximum gamma aspect

    International Nuclear Information System (INIS)

    Thumim, A.D.

    1975-01-01

    A scintillation counter, particularly for counting gamma ray photons, includes a massive lead radiation shield surrounding a sample-receiving zone. The shield is disassembleable into a plurality of segments to allow facile installation and removal of a photomultiplier tube assembly, the segments being so constructed as to prevent straight-line access of external radiation through the shield into radiation-responsive areas. Provisions are made for accurately aligning the photomultiplier tube with respect to one or more sample-transmitting bores extending through the shield to the sample receiving zone. A sample elevator, used in transporting samples into the zone, is designed to provide a maximum gamma-receiving aspect to maximize the gamma detecting efficiency. (U.S.)

  15. Photon-photon interactions

    International Nuclear Information System (INIS)

    Gilman, F.J.

    1980-01-01

    A brief summary of the present status of photon-photon interactions is presented. Stress is placed on the use of two-photon collisions to test present ideas on the quark constituents of hadrons and on the theory of strong interactions

  16. Multi-element proportional counter for radiation protection measurements

    International Nuclear Information System (INIS)

    Kliauga, P.; Rossi, H.H.; Johnson, G.

    1988-01-01

    This article discusses design modifications of a multi-element proportional counter. The original counter exhibited poor resolution, as measured by the width of the event-size spectrum for low-energy photons. It was also suspected that the field inside each volume was not sufficiently symmetric. Results of the modifications showed that a dramatic improvement in resolution could be obtained in the chamber with tissue-equivalent septa if their potentials were adjusted to obtain optimal resolution. The full width at half maximum then approached, although it did not equal, that of a standard spherical counter

  17. Scintillation counter based radiation dosimeter

    International Nuclear Information System (INIS)

    Shin, Jeong Hyun

    2009-02-01

    environmental radiation. The operation mechanism is quite simple. First step is scintillation in scintillator. Second step is conversion from photon to charge in photodiode. Third step is signal amplification in charge amplifier. Fourth step is pulse shaping for discrimination in shaping amp. Fifth step is reduction of noise pulse in discriminator. Final step is pulse counting in counter. This new radiation detection system can give reliable radiation dose data as low cost. So we can supply this new radiation dosimeter to the area near radiation and nuclear facilities. I will hope this new radiation dosimeter can contribute to the public acceptance on radiation use and nuclear facilities

  18. Counter-cryptanalysis

    NARCIS (Netherlands)

    M.M.J. Stevens (Marc); R. Canetti; J.A. Garay

    2013-01-01

    textabstractWe introduce \\emph{counter-cryptanalysis} as a new paradigm for strengthening weak cryptographic primitives against cryptanalytic attacks. Redesigning a weak primitive to more strongly resist cryptanalytic techniques will unavoidably break backwards compatibility. Instead,

  19. A Neutron Rem Counter

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, I Oe; Braun, J

    1964-01-15

    A neutron detector is described which measures the neutron dose rate in rem/h independently of the energy of the neutrons from thermal to 15 MeV. The detector consists of a BF{sub 3} proportional counter surrounded by a shield made of polyethylene and boron plastic that gives the appropriate amount of moderation and absorption to the impinging neutrons to obtain rem response. Two different versions have been developed. One model can utilize standard BF{sub 3} counters and is suitable for use in installed monitors around reactors and accelerators and the other model is specially designed for use in a portable survey instrument. The neutron rem counter for portable instruments has a sensitivity of 2.4 cps/mrem/h and is essentially nondirectional in response. With correct bias setting the counter is insensitive to gamma exposure up to 200 r/h from Co-60.

  20. Photon-photon collisions

    International Nuclear Information System (INIS)

    Burke, D.L.

    1982-10-01

    Studies of photon-photon collisions are reviewed with particular emphasis on new results reported to this conference. These include results on light meson spectroscopy and deep inelastic e#betta# scattering. Considerable work has now been accumulated on resonance production by #betta##betta# collisions. Preliminary high statistics studies of the photon structure function F 2 /sup #betta#/(x,Q 2 ) are given and comments are made on the problems that remain to be solved

  1. Photon-photon collisions

    International Nuclear Information System (INIS)

    Haissinski, J.

    1986-06-01

    The discussions presented in this paper deal with the following points: distinctive features of gamma-gamma collisions; related processes; photon-photon elastic scattering in the continuum and γγ →gg; total cross section; γγ → V 1 V 2 (V=vector meson); radiative width measurements and light meson spectroscopy; exclusive channels at large /t/; jets and inclusive particle distribution in γγ collisions; and, the photon structure function F γ 2

  2. Photon-photon colliders

    International Nuclear Information System (INIS)

    Sessler, A.M.

    1995-04-01

    Since the seminal work by Ginsburg, et at., the subject of giving the Next Linear Collider photon-photon capability, as well as electron-positron capability, has drawn much attention. A 1990 article by V.I. Teinov describes the situation at that time. In March 1994, the first workshop on this subject was held. This report briefly reviews the physics that can be achieved through the photon-photon channel and then focuses on the means of achieving such a collider. Also reviewed is the spectrum of backscattered Compton photons -- the best way of obtaining photons. We emphasize the spectrum actually obtained in a collider with both polarized electrons and photons (peaked at high energy and very different from a Compton spectrum). Luminosity is estimated for the presently considered colliders, and interaction and conversion-point geometries are described. Also specified are laser requirements (such as wavelength, peak power, and average power) and the lasers that might be employed. These include conventional and free-electron lasers. Finally, we describe the R ampersand D necessary to make either of these approaches viable and explore the use of the SLC as a test bed for a photon-photon collider of very high energy

  3. Single photons on demand

    International Nuclear Information System (INIS)

    Grangier, P.; Abram, I.

    2004-01-01

    Quantum cryptography and information processing are set to benefit from developments in novel light sources that can emit photons one by one. Quantum mechanics has gained a reputation for making counter-intuitive predictions. But we rarely get the chance to witness these effects directly because, being humans, we are simply too big. Take light, for example. The light sources that are familiar to us, such as those used in lighting and imaging or in CD and DVD players, are so huge that they emit billions and billions of photons. But what if there was a light source that emitted just one photon at a time? Over the past few years, new types of light source that are able to emit photons one by one have been emerging from laboratories around the world. Pulses of light composed of a single photon correspond to power flows in the femtowatt range - a million billion times less than that of a table lamp. The driving force behind the development of these single-photon sources is a range of novel applications that take advantage of the quantum nature of light. Quantum states of superposed and entangled photons could lead the way to guaranteed-secure communication, to information processing with unprecedented speed and efficiency, and to new schemes for quantum teleportation. (U.K.)

  4. Nuclear timer/counter

    International Nuclear Information System (INIS)

    Wuthayavanich, S.

    1978-01-01

    This thesis represents the development of a Timer/COUNTER compatible to the standard Nuclear Instrument Module Specifications. The unit exhibits high accuracy, light weight and ease of maintenance. The unit also has a built-in precision discriminator to discriminate unwanted signals that may cause interference in counting. With line frequency time base the timer can be preset in steps from 0.1 sec. to 9 x 10 5 min. The counter with six digits miniature display and an overflow output has a maximum counting rate of 10 MHz. The accumulated counting data can be transferred to a teletype or printer for hard copy printout with the aid of ORTEC 777 Line Printer or 432 A Print-out Control or any print out interface with input compatible to the print output of the Timer/Counter. Owing to its NIM compatibility the unit is directly powered by the NIM power supply

  5. Test of a large size acrylic scintillation counter

    International Nuclear Information System (INIS)

    Bertino, M.; De Zorzi, G.; Zanello, D.

    1984-01-01

    We have tested the behaviour of an acrylic scintillator measuring the attenuation length and the time resolution of a 7.8 m long counter. On a small sample the photon yield relative to the NE 110 plastic has been measured. (orig.)

  6. An efficient anticoincidence counter

    CERN Multimedia

    1977-01-01

    This scintillation counter (about 25 cm diameter) was prepared at CERN for an experiment at the Saclay 600 MeV electron linac studying molecular processes originated in liquid hydrogen by muons. The counter is meant to surround the target and detect charged particles emerging from the hydrogen. The experiment was a CERN-Saclay collaboration which used the linac so as to take advantage of the time structure of the electron beam(see CERN Courier Sep 1977 and J. Bardin et al. Phys. Lett. B104 (1981) 320)

  7. TOP counter for particle identification at the Belle II experiment

    Energy Technology Data Exchange (ETDEWEB)

    Inami, Kenji

    2014-12-01

    Ring imaging Cherenkov counter, named TOP counter, utilizing precise photon detection timing has been developed as a particle identification detector for the Belle II experiment. The real size prototype has been produced and tested with 2 GeV positrons at Spring-8 LEPS beam line. The quartz radiator production and assembling with microchannel plate photomultipliers was successfully carried out. The beam test data shows good agreement with full Monte-Carlo simulation results in the ring image and the distribution of number of detected photons and timing information. - Highlights: • TOP counter was developed as a particle identification detector for the Belle II experiment. • The real size prototype was produced and tested with 2 GeV positrons. • The quartz radiator production and assembling with MCP-PMT was successfully carried out. • The beam test data shows good agreement with full Monte-Carlo simulation results.

  8. Irradiated fuel bundle counter

    International Nuclear Information System (INIS)

    Campbell, J.W.; Todd, J.L.

    1975-01-01

    The design of a prototype safeguards instrument for determining the number of irradiated fuel assemblies leaving an on-power refueled reactor is described. Design details include radiation detection techniques, data processing and display, unattended operation capabilities and data security methods. Development and operating history of the bundle counter is reported. (U.S.)

  9. Irradiated fuel bundle counter

    International Nuclear Information System (INIS)

    Campbell, J.W.; Todd, J.L.

    1975-01-01

    The design of a prototype safeguards instrument for determining the number of irradiated fuel assemblies leaving an on-power refueled reactor is described. Design details include radiation detection techniques, data processing and display, unattended operation capabilities and data security methods. Development and operating history of the bundle counter is reported

  10. Counter radicalization development assistance

    OpenAIRE

    van Hippel, Karin

    2006-01-01

    The paper reviews current research and practice and recommends strategies for development agencies working in the Arab and Muslim world. It builds on the basic assumption that the realization of the Millennium Development Goals will be vital to reduce support for terrorism in the long term. Within this overall framework, emphasis is placed on particular programs that could be specifically applied to counter radicalization.

  11. Whole-body counter

    Energy Technology Data Exchange (ETDEWEB)

    Fedorov, G A; Kosterev, V V

    1975-01-24

    A counter for detecting radiation of a man (CRM) is described, which consists of two measuring converters and a recording device. In order to obtain data on spatial distribution of a gamma-radiating nuclide studied, a fixed collimator and a mobile coder made of separate slit elements are placed between the measuring converters and an object investigated.

  12. Electromagnetically Operated Counter

    Science.gov (United States)

    Goldberg, H D; Goldberg, M I

    1951-12-18

    An electromagnetically operated counter wherein signals to be counted are applied to cause stepwise rotation of a rotatable element which is connected to a suitable register. The mechanism involved consists of a rotatable armature having three spaced cores of magnetic material and a pair of diametrically opposed electromagnets with a suitable pulsing circuit to actuate the magnets.

  13. Microchip Coulter particle counter

    DEFF Research Database (Denmark)

    Larsen, Ulrik Darling; Blankenstein, Gert; Branebjerg, J.

    1997-01-01

    This paper presents a micro device employing the Coulter principle for counting and sizing of living cells and particles in liquid suspension. The microchip Coulter particle counter (μCPC) has been employed in a planar silicon structure covered with glass, which enables detailed observation during...

  14. Calibration and Monte Carlo modelling of neutron long counters

    CERN Document Server

    Tagziria, H

    2000-01-01

    The Monte Carlo technique has become a very powerful tool in radiation transport as full advantage is taken of enhanced cross-section data, more powerful computers and statistical techniques, together with better characterisation of neutron and photon source spectra. At the National Physical Laboratory, calculations using the Monte Carlo radiation transport code MCNP-4B have been combined with accurate measurements to characterise two long counters routinely used to standardise monoenergetic neutron fields. New and more accurate response function curves have been produced for both long counters. A novel approach using Monte Carlo methods has been developed, validated and used to model the response function of the counters and determine more accurately their effective centres, which have always been difficult to establish experimentally. Calculations and measurements agree well, especially for the De Pangher long counter for which details of the design and constructional material are well known. The sensitivit...

  15. The scintillation counter system at the SAPHIR detector

    International Nuclear Information System (INIS)

    Bour, D.

    1989-10-01

    The scintillation-counters system of the SAPHIR-detector at the stretcher accelerator ELSA in Bonn consists of 64 counters. It supplies a fast hadronic trigger and is utilizised for the particle identification by time of flight measurements. Prototypes of the counters (340x21.25 x 6.0 cm 3 ) had been tested. The contribution to the resolution of the time of flight measurement was measured to σ=125 ps, the effective light velocity to 17.5 ns/cm and the attenuation length of 7.8 m. A pion kaon separation is possible up to a momentum of 1 GeV/c with time of flight measurement. With the first photon-beam at SAPHIR the counters were tested, first triggers were obtained and evaluated. (orig.) [de

  16. Proportional counter end effects eliminator

    International Nuclear Information System (INIS)

    Meekins, J.F.

    1976-01-01

    An improved gas-filled proportional counter which includes a resistor network connected between the anode and cathode at the ends of the counter in order to eliminate ''end effects'' is described. 3 Claims, 2 Drawing Figures

  17. Over-the-Counter Medicines

    Science.gov (United States)

    Over-the-counter (OTC) medicines are drugs you can buy without a prescription. Some OTC medicines relieve aches, pains and itches. ... medicine is safe enough to sell over-the-counter. Taking OTC medicines still has risks. Some interact ...

  18. Photon-photon collisions

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, S.J.

    1985-01-01

    The study of photon-photon collisions has progressed enormously, stimulated by new data and new calculational tools for QCD. In the future we can expect precise determinations of ..cap alpha../sub s/ and ..lambda../sup ms/ from the ..gamma..*..gamma.. ..-->.. ..pi../sup 0/ form factor and the photon structure function, as well as detailed checks of QCD, determination of the shape of the hadron distribution amplitudes from ..gamma gamma.. ..-->.. H anti H, reconstruction of sigma/sub ..gamma gamma../ from exclusive channels at low W/sub ..gamma gamma../, definitive studies of high p/sub T/ hadron and jet production, and studies of threshold production of charmed systems. Photon-photon collisions, along with radiative decays of the psi and UPSILON, are ideal for the study of multiquark and gluonic resonances. We have emphasized the potential for resonance formation near threshold in virtually every hadronic exclusive channel, including heavy quark states c anti c c anti c, c anti c u anti u, etc. At higher energies SLC, LEP, ...) parity-violating electroweak effects and Higgs production due to equivalent Z/sup 0/ and W/sup + -/ beams from e ..-->.. eZ/sup 0/ and e ..-->.. nu W will become important. 44 references.

  19. Photon-photon collisions

    International Nuclear Information System (INIS)

    Brodsky, S.J.

    1985-01-01

    The study of photon-photon collisions has progressed enormously, stimulated by new data and new calculational tools for QCD. In the future we can expect precise determinations of α/sub s/ and Λ/sup ms/ from the γ*γ → π 0 form factor and the photon structure function, as well as detailed checks of QCD, determination of the shape of the hadron distribution amplitudes from γγ → H anti H, reconstruction of sigma/sub γγ/ from exclusive channels at low W/sub γγ/, definitive studies of high p/sub T/ hadron and jet production, and studies of threshold production of charmed systems. Photon-photon collisions, along with radiative decays of the psi and UPSILON, are ideal for the study of multiquark and gluonic resonances. We have emphasized the potential for resonance formation near threshold in virtually every hadronic exclusive channel, including heavy quark states c anti c c anti c, c anti c u anti u, etc. At higher energies SLC, LEP, ...) parity-violating electroweak effects and Higgs production due to equivalent Z 0 and W +- beams from e → eZ 0 and e → nu W will become important. 44 references

  20. Photon-photon collisions

    International Nuclear Information System (INIS)

    Field, J.H.

    1984-01-01

    The current status, both theoretical and experimental, of two photon collision physics is reviewed with special emphasis on recent experimental results from e + e - storage rings. After a complete presentation of the helicity amplitude formalism for the general process e + e - → Xe + e - , various approximations (transverse photon, Weisaecker Williams) are discussed. Beam polarisation effects and radiative corrections are also briefly considered. A number of specific processes, for which experimental results are now available, are then described. In each case existing theoretical prediction are confronted with experimental results. The processes described include single resonance production, lepton and hadron pair production, the structure functions of the photon, the production of high Psub(T) jets and the total photon photon cross section. In the last part of the review the current status of the subject is summarised and some comments are made on future prospects. These include both extrapolations of current research to higher energy machines (LEP, HERA) as well as a brief mention of both the technical realisation and the physics interest of the real γγ and eγ collisions which may be possible using linear electron colliders in the 1 TeV energy range

  1. Update on photon-photon collisions

    International Nuclear Information System (INIS)

    Arteaga-Romero, N.; Cochard, G.; Ong, S.; Amiens Univ., 80; Carimalo, C.; Kessler, P.; Nicolaidis, A.; Parisi, J.; Courau, A.

    1980-03-01

    This report is the continuation of the 'Update' of last year (L.P.C. 79-03, March 1979, in French). In Part I, the structure functions of the photon in QCD are examined. It is shown that, while large psub(T) hadron production is similar to some extent in γγ collisions and in hadron-hadron collisions, the point-like nature of the photon introduces new terms which are entirely calculable, providing new means to test the dynamics of strong interactions. In Part II, problems of analysis in γγ experiments are discussed. The pros and cons of various options with regard to the measurement of outgoing electrons (non-tagging, finite-angle tagging, tagging at 0 0 ) are compared. It is shown that (a) non-tagging may be applied to the study of a limited number of processes only; (b) finite-angle tagging counters allow for various possibilities (double-tagging, single-tagging, double anti-tagging), but none of them is entirely satisfactory; (c) the ideal measurement is double tagging at 0 0 , provided the problem of bremsstrahlung saturation of the tagging counters can be solved

  2. Fundamentals of gas counters

    International Nuclear Information System (INIS)

    Bateman, J.E.

    1994-01-01

    The operation of gas counters used for detecting radiation is explained in terms of the four fundamental physical processes which govern their operation. These are 1) conversion of neutral radiation into charged particles, 2) ionization of the host gas by a fast charge particle 3) transport of the gas ions to the electrodes and 4) amplification of the electrons in a region of enhanced electric field. Practical implications of these are illustrated. (UK)

  3. CONFERENCE: Photon-photon collisions

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    Despite being difficult to observe, photon-photon collisions have opened up a range of physics difficult, or even impossible, to access by other methods. The progress which has been made in this field was evident at the fifth international workshop on photon-photon collisions, held in Aachen from 13-16 April and attended by some 120 physicists

  4. Photon technology. Hard photon technology; Photon technology. Hard photon gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    Research results of hard photon technology have been summarized as a part of novel technology development highly utilizing the quantum nature of photon. Hard photon technology refers to photon beam technologies which use photon in the 0.1 to 200 nm wavelength region. Hard photon has not been used in industry due to the lack of suitable photon sources and optical devices. However, hard photon in this wavelength region is expected to bring about innovations in such areas as ultrafine processing and material synthesis due to its atom selective reaction, inner shell excitation reaction, and spatially high resolution. Then, technological themes and possibility have been surveyed. Although there are principle proposes and their verification of individual technologies for the technologies of hard photon generation, regulation and utilization, they are still far from the practical applications. For the photon source technology, the laser diode pumped driver laser technology, laser plasma photon source technology, synchrotron radiation photon source technology, and vacuum ultraviolet photon source technology are presented. For the optical device technology, the multi-layer film technology for beam mirrors and the non-spherical lens processing technology are introduced. Also are described the reduction lithography technology, hard photon excitation process, and methods of analysis and measurement. 430 refs., 165 figs., 23 tabs.

  5. Systematic studies of small scintillators for new sampling calorimeter

    Indian Academy of Sciences (India)

    A new sampling calorimeter using very thin scintillators and the multi-pixel photon counter (MPPC) has been proposed to produce better position resolution for the international linear collider (ILC) experiment. As part of this R & D study, small plastic scintillators of different sizes, thickness and wrapping reflectors are ...

  6. A nuclear proportional counter

    International Nuclear Information System (INIS)

    1973-01-01

    The invention relates to a nuclear proportional counter comprising in a bulb filled with a low-pressure gas, a wire forming an anode and a cathode, characterized in that said cathode is constituted by two plane plates parallel to each other and to the anode wire, and in that two branches of a circuit are connected to the anode wire end-portions, each branch comprising a pre-amplifier, a measuring circuit consisting of a differentiator-integrator-differentiator amplifier and a zero detector, one of the branches comprising an adjustable delay circuit, both branches jointly attacking a conversion circuit for converting the pulse duration into amplitudes said conversion circuit being followed by a multi-channel analyzer, contingently provided with a recorder [fr

  7. Silica aerogel Cerenkov counter

    International Nuclear Information System (INIS)

    Yasumi, S.; Masaike, A.; Yamamoto, A.; Yoshimura, Y.; Kawai, H.

    1984-03-01

    In order to obtain silica aerogel radiators of good quality, the prescription used by Saclay group has been developed. We have done several experiments using beams from KEK.PS to test the performance of a Cerenkov counter with aerogel modules produced in KEK. It turned out that these modules had excellent quality. The production rate of silica aerogel in KEK is 15 -- 20 litres a week. Silica aerogel modules of 20 x 10 x 3 cm 3 having the refractive index of 1.058 are successfully being used by Kyoto University group in the KEK experiment E92 (Σ). Methodes to produce silica aerogel with higher refractive index than 1.06 has been investigated both by heating an module with the refractive index of 1.06 and by hydrolyzing tetraethyl silicate. (author)

  8. Polychromatic photons

    DEFF Research Database (Denmark)

    Keller, Ole

    2002-01-01

    train quantum electrodynamics. A brief description of particle (photon) position operators is given, and it is shown that photons usually are only algebraically confined in an emission process. Finally, it is demonstrated that the profile of the birth domain of a radio-frequency photon emitted...

  9. Space and power efficient hybrid counters array

    Science.gov (United States)

    Gara, Alan G [Mount Kisco, NY; Salapura, Valentina [Chappaqua, NY

    2009-05-12

    A hybrid counter array device for counting events. The hybrid counter array includes a first counter portion comprising N counter devices, each counter device for receiving signals representing occurrences of events from an event source and providing a first count value corresponding to a lower order bits of the hybrid counter array. The hybrid counter array includes a second counter portion comprising a memory array device having N addressable memory locations in correspondence with the N counter devices, each addressable memory location for storing a second count value representing higher order bits of the hybrid counter array. A control device monitors each of the N counter devices of the first counter portion and initiates updating a value of a corresponding second count value stored at the corresponding addressable memory location in the second counter portion. Thus, a combination of the first and second count values provide an instantaneous measure of number of events received.

  10. Permanently calibrated interpolating time counter

    International Nuclear Information System (INIS)

    Jachna, Z; Szplet, R; Kwiatkowski, P; Różyc, K

    2015-01-01

    We propose a new architecture of an integrated time interval counter that provides its permanent calibration in the background. Time interval measurement and the calibration procedure are based on the use of a two-stage interpolation method and parallel processing of measurement and calibration data. The parallel processing is achieved by a doubling of two-stage interpolators in measurement channels of the counter, and by an appropriate extension of control logic. Such modification allows the updating of transfer characteristics of interpolators without the need to break a theoretically infinite measurement session. We describe the principle of permanent calibration, its implementation and influence on the quality of the counter. The precision of the presented counter is kept at a constant level (below 20 ps) despite significant changes in the ambient temperature (from −10 to 60 °C), which can cause a sevenfold decrease in the precision of the counter with a traditional calibration procedure. (paper)

  11. 300-MHz optical discriminator-counter

    International Nuclear Information System (INIS)

    Turko, B.; Lo, C.C.

    1981-07-01

    The prediction of future CO 2 content in the atmosphere is not completely credible because the oceanographers and terrestrial ecologists do not agree on the global CO 2 balance. Very precise measurements of O 2 /N 2 ratio using Raman scattering over a few years' period could provide important information and lead to the explanation of the disparity in the atmospheric CO 2 balance. An optical discriminator-counter has been developed to count closely spaced optical events in the few photon level. Simulated optical events as close as 2.5 ns apart had been positively detected by using selected photomultipliers and optimized discriminators. Testing of the optical discriminator-counter was done by using an electrical pulse pair spaced 3 ns apart and also by a similar optical pulse pair generated by fast light-emitting diode. The photomultiplier is capable of counting an average single photoelectron pulse frequency of 50 MHz and has a sensitive detecting area of 50 mm in diameter. The discriminator performance is discussed

  12. A portable neutron coincidence counter

    Energy Technology Data Exchange (ETDEWEB)

    Peurrung, A.J.; Bowyer, S.M.; Craig, R.A.; Dudder, G.B.; Knopf, M.A.; Panisko, M.E.; Reeder, P.L.; Stromswold, D.C.; Sunberg, D.S.

    1996-11-01

    Pacific Northwest National Laboratory has designed and constructed a prototype portable neutron coincidence counter intended for use in a variety of applications, such as the verification and inspection of weapons components, safety measurements for novel and challenging situations, portable portal deployment to prevent the transportation of fissile materials, uranium enrichment measurements in hard-to-reach locations, waste assays for objects that cannot be measured by existing measurement systems, and decontamination and decommissioning. The counting system weighs less than 40 kg and is composed of parts each weighing no more than 5 kg. In addition, the counter`s design is sufficiently flexible to allow rapid, reliable assembly around containers of nearly arbitrary size and shape. The counter is able to discern the presence of 1 kg of weapons-grade plutonium within an ALR-8 (30-gal drum) in roughly 100 seconds and 10 g in roughly 1000 seconds. The counter`s electronics are also designed for maximum adaptability, allowing operation under a wide variety of circumstances, including exposure to gamma-ray fields of 1 R/h. This report provides a detailed review of the design and construction process. Finally, preliminary experimental measurements that confirm the performance capabilities of this counter are discussed. 6 refs., 18 figs., 3 tabs.

  13. Multiple channel programmable coincidence counter

    Science.gov (United States)

    Arnone, Gaetano J.

    1990-01-01

    A programmable digital coincidence counter having multiple channels and featuring minimal dead time. Neutron detectors supply electrical pulses to a synchronizing circuit which in turn inputs derandomized pulses to an adding circuit. A random access memory circuit connected as a programmable length shift register receives and shifts the sum of the pulses, and outputs to a serializer. A counter is input by the adding circuit and downcounted by the seralizer, one pulse at a time. The decoded contents of the counter after each decrement is output to scalers.

  14. What is Counter-Enlightenment?

    OpenAIRE

    Darrin M. McMahon

    2017-01-01

    This article counters recent suggestions that there was no such thing as a “Counter-Enlightenment” or “Counter-Enlightenments,” and that such terms ought thus to be abandoned.   While acknowledging inevitable difficulties with the terms, the article argues that there can be no doubting the reality.   European countries faced a variety of vehement and self-conscious movements that defined themselves precisely through their opposition to what they took to be the corrosive effects of the Enlight...

  15. X-ray diffraction analysis device with electronic photon counter

    International Nuclear Information System (INIS)

    Fillit, R.Y.; Bruyas, H.; Patay, F.

    1985-01-01

    The means provided to control the movements around the three axes are composed of step-by-step motors related to exits control logic which is connected to the calculation and monitored by a clock. The clock monitors also the calculator so as that the calculator controls, together with the programmable clock and control logic, the coordination of the whole rotation movements, along the three rotation axes, their velocity, their duration and the acquisition of the measured intensities of the diffracted X-ray beam [fr

  16. Photonic Hypercrystals

    Directory of Open Access Journals (Sweden)

    Evgenii E. Narimanov

    2014-10-01

    Full Text Available We introduce a new “universality class” of artificial optical media—photonic hypercrystals. These hyperbolic metamaterials, with periodic spatial variation of dielectric permittivity on subwavelength scale, combine the features of optical metamaterials and photonic crystals. In particular, surface waves supported by a hypercrystal possess the properties of both the optical Tamm states in photonic crystals and surface-plasmon polaritons at the metal-dielectric interface.

  17. Microwave photonics

    CERN Document Server

    Lee, Chi H

    2006-01-01

    Wireless, optical, and electronic networks continue to converge, prompting heavy research into the interface between microwave electronics, ultrafast optics, and photonic technologies. New developments arrive nearly as fast as the photons under investigation, and their commercial impact depends on the ability to stay abreast of new findings, techniques, and technologies. Presenting a broad yet in-depth survey, Microwave Photonics examines the major advances that are affecting new applications in this rapidly expanding field.This book reviews important achievements made in microwave photonics o

  18. Photon detector composed of metal and semiconductor nanoparticles

    International Nuclear Information System (INIS)

    Takahashi, Atsuo; Minoura, Norihiko; Karube, Isao

    2005-01-01

    Applying the function of the single electron transistor, a novel photon detector consisting of a self-assembled structure of metal and semiconductor nanoparticles and an organic insulating layer was developed. It showed coulomb blockade behavior under dark conditions and remarkable increase in current corresponding to light intensity under light irradiation. Ultraweak photon emission of about 600 counts per second in the ultraviolet region could be detected at room temperature by this photon counter

  19. In-vivo radiation counter

    International Nuclear Information System (INIS)

    Pollard, D.E.

    1983-01-01

    This patent specification describes a radiation counter utilizing at least one detector for sensing radiation from a living body. The radiation counter also includes an aperture for forming a corridor between the body and the detector. A shield outside the corridor prevents passage of background radiation through the corridor and gaining access to the detector. The counter also includes a device for isolating a selected portion of the body from the corridor such that radiation counting is restricted to a region of the body through a separate detector. The corridor formation permits a user to stand in an upright position while the detector and detectors are able to separately monitor different sections of the body. The radiation counter overcomes the problem of obtaining accurate and quick measurements or radiation doses sustained by a large group of persons. (author)

  20. High-speed parallel counter

    International Nuclear Information System (INIS)

    Gus'kov, B.N.; Kalinnikov, V.A.; Krastev, V.R.; Maksimov, A.N.; Nikityuk, N.M.

    1985-01-01

    This paper describes a high-speed parallel counter that contains 31 inputs and 15 outputs and is implemented by integrated circuits of series 500. The counter is designed for fast sampling of events according to the number of particles that pass simultaneously through the hodoscopic plane of the detector. The minimum delay of the output signals relative to the input is 43 nsec. The duration of the output signals can be varied from 75 to 120 nsec

  1. Channel coincidence counter: version 1

    International Nuclear Information System (INIS)

    Krick, M.S.; Menlove, H.O.

    1980-06-01

    A thermal neutron coincidence counter has been designed for the assay of fast critical assembly fuel drawers and plutonium-bearing fuel rods. The principal feature of the detector is a 7-cm by 7-cm by 97-cm detector channel, which provides a uniform neutron detection efficiency of 16% along the central 40 cm of the channel. The electronics system is identical to that used for the High-Level Neutron Coincidence Counter

  2. Single-photon detector operating under extremely high background photon flux conditions

    International Nuclear Information System (INIS)

    Prochazka, Ivan; Sopko, Bruno; Blazej, Josef

    2009-01-01

    We are reporting our results in research and development in the field of avalanche semiconductor single-photon detectors and their application. Our goal was a development of a solid-state photon-counting detector capable of high-precision photon arrival time tagging in extremely harsh operating conditions. The background photon flux exceeding 10 9 photons per second hitting the detector active area should not avoid the useful signal detection and recognition on the signal level of units of photons per second. This is background photon flux about two orders of magnitude higher than what the conventional solid-state photon counters accept. The detection timing resolution should be better than 100 ps and the delay stability should be on picosecond level. We have developed and tested the active quenched and gated avalanche structure on silicon providing the required features in connection with the K14 detection chips. The detector is capable of gated operation under the conditions of background photon flux of 5x10 9 photons per second. The operational detector tolerates long term exposures to the input photon flux exceeding 10 15 photons (>1 mW) per second without damage.

  3. Portable microcomputer controlled radiation counter

    International Nuclear Information System (INIS)

    Mason, E.W.; Weber, J.M.

    1984-01-01

    A portable microcomputer controlled counter for use as a radiation counter is described. The counter uses digital processing of input pulses from a radiation detector. The number of counts received by the microcomputer per unit time is used to calculate a value for display using a calibration factor obtained during physical calibration of the instrument with a radiation source or with a pulse generator. The keyboard is used to enter calibration points. The number of calibration points which may be entered depends on the degree of accuracy desired by the user. The high voltage generator which drives the detector is triggered by pulses from the microcomputer in relation to the count rate. After processing the count, the resulting count rate or dose rate is displayed on the liquid crystal display. The counter is autoranging in which the decimal point is shifted as necessary by the microcomputer. The units displayed are determined by the user by means of a multiposition switch. Low battery and an overrange condition are displayed. An interface is provided via a connector to allow parallel transmission of data to peripheral devices. Low battery power consumption is featured. The counter is capable of providing more accurate readings than currently available counters

  4. Photon technology. Hard photon technology; Photon technology. Hard photon gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    For the application of photon to industrial technologies, in particular, a hard photon technology was surveyed which uses photon beams of 0.1-200nm in wavelength. Its features such as selective atom reaction, dense inner shell excitation and spacial high resolution by quantum energy are expected to provide innovative techniques for various field such as fine machining, material synthesis and advanced inspection technology. This wavelength region has been hardly utilized for industrial fields because of poor development of suitable photon sources and optical devices. The developmental meaning, usable time and issue of a hard photon reduction lithography were surveyed as lithography in ultra-fine region below 0.1{mu}m. On hard photon analysis/evaluation technology, the industrial use of analysis, measurement and evaluation technologies by micro-beam was viewed, and optimum photon sources and optical systems were surveyed. Prediction of surface and surface layer modification by inner shell excitation, the future trend of this process and development of a vacuum ultraviolet light source were also surveyed. 383 refs., 153 figs., 17 tabs.

  5. Inverse photon-photon processes

    International Nuclear Information System (INIS)

    Carimalo, C.; Crozon, M.; Kesler, P.; Parisi, J.

    1981-12-01

    We here consider inverse photon-photon processes, i.e. AB → γγX (where A, B are hadrons, in particular protons or antiprotons), at high energies. As regards the production of a γγ continuum, we show that, under specific conditions the study of such processes might provide some information on the subprocess gg γγ, involving a quark box. It is also suggested to use those processes in order to systematically look for heavy C = + structures (quarkonium states, gluonia, etc.) showing up in the γγ channel. Inverse photon-photon processes might thus become a new and fertile area of investigation in high-energy physics, provided the difficult problem of discriminating between direct photons and indirect ones can be handled in a satisfactory way

  6. The suppression of destructive sparks in parallel plate proportional counters

    Energy Technology Data Exchange (ETDEWEB)

    Cockshott, R.A.; Mason, I.M.

    1984-02-01

    The authors find that high energy background events produce localised sparks in parallel plate counters when operated in the proportional mode. These sparks increase dead-time and lead to degradation ranging from electrode damage to spurious pulsing and continuous breakdown. The problem is particularly serious in low energy photon detectors for X-ray astronomy which are required to have lifetimes of several years in the high radiation environment of space. For the parallel plate imaging detector developed for the European X-ray Observatory Satellite (EXOSAT) they investigate quantitatively the spark thresholds, spark rates and degradation processes. They discuss the spark mechanism, pointing out differences from the situation in spark chambers and counters. They show that the time profile of the sparks allows them to devise a spark suppression system which reduces the degradation rate by a factor of ''200.

  7. The design of the DUPIC spent fuel bundle counter

    International Nuclear Information System (INIS)

    Menlove, H.O.; Rinard, P.M.; Kroncke, K.E.; Lee, Y.G.

    1997-05-01

    A neutron coincidence detector had been designed to measure the amount of curium in the fuel bundles and associated process samples used in the direct use of plutonium in Canadian deuterium-uranium (CANDU) fuel cycle. All of the sample categories are highly radioactive from the fission products contained in the pressurized water reactor (PWR) spent fuel feed stock. Substantial shielding is required to protect the He-3 detectors from the intense gamma rays. The Monte Carlo neutron and photon calculational code has been used to design the counter with a uniform response profile along the length of the CANDU-type fuel bundle. Other samples, including cut PWR rods, process powder, waste, and finished rods, can be measured in the system. This report describes the performance characteristics of the counter and support electronics. 3 refs., 23 figs., 6 tabs

  8. What is Counter-Enlightenment?

    Directory of Open Access Journals (Sweden)

    Darrin M. McMahon

    2017-02-01

    Full Text Available This article counters recent suggestions that there was no such thing as a “Counter-Enlightenment” or “Counter-Enlightenments,” and that such terms ought thus to be abandoned.   While acknowledging inevitable difficulties with the terms, the article argues that there can be no doubting the reality.   European countries faced a variety of vehement and self-conscious movements that defined themselves precisely through their opposition to what they took to be the corrosive effects of the Enlightenment.  In the process, they defined the main terms of an enduring vision of the world that we now associate with the Right.

  9. Plea and counter-plea

    International Nuclear Information System (INIS)

    1979-06-01

    The bulk of papers written during the hearing 'Plea and counter-plea', the so-called 'Gorleben hearing', which was held from 28th March until 3rd April 1979, comprises ca. 4,200 pages. It consists of the written comments put forward by the critics of nuclear energy, the minutes of the hearing as well as the supplementary statements of the counter-critics. This report is trying to confront those essential objections made by the critics which put in doubt the feasibility of a fuel-cycle centre with regard to safety engineering with the facts which are considered correct from the view of the DWK. The oral and written explanations of the counter-critics are particularly referred to in this debate. (orig./HP) [de

  10. Portable counter for geological research

    Energy Technology Data Exchange (ETDEWEB)

    Russell, O J

    1949-05-01

    A portable counter which has been developed for prospecting for radio-active uranium and thorium minerals, for general geological investigations, and as an ultra-sensitive detector of lost or mislaid radium, is described. The aforementioned general usage includes the identification of changes in strata by means of the investigation of the slight amount of residual activity pressent in most minerals. The apparatus, which consists essentially of a scaled-down version of a standard laboratory Geiger-Muller counter, is highly sensitive since a variation equivalent to 4% of the cosmic ray background can be detected by a three-minute count.

  11. ''Conventional'' Cerenkov counters at ISABELLE

    International Nuclear Information System (INIS)

    Foley, K.J.

    1977-01-01

    Cherenkov counters to be used with ISABELLE are described. The three counters used in the Hadron Spectrometer can be used to identify particles in the range 10 to 40 GeV/c with pions separated from heavier particles down to approximately 3 GeV/c. A longer spectrometer for 400 x 400 GeV operation should also be used. The spectrometers may be used with CO 2 and H 2 . The range of particle identification of 8 to 60 GeV/c with pions separated from heavier particles down to approximately 5 GeV/c is possible

  12. Silica aerogel threshold Cherenkov counters for the JLab Hall A spectrometers: improvements and proposed modifications

    CERN Document Server

    Lagamba, L; Colilli, S; Crateri, R; De Leo, R; Frullani, S; Garibaldi, F; Giuliani, F; Gricia, M; Iodice, M; Iommi, R; Leone, A; Lucentini, M; Mostarda, A; Nappi, E; Perrino, R; Pierangeli, L; Santavenere, F; Urciuoli, G M

    2001-01-01

    Recently approved experiments at Jefferson Lab Hall A require a clean kaon identification in a large electron, pion, and proton background environment. To this end, improved performance is required of the silica aerogel threshold Cherenkov counters installed in the focal plane of the two Hall A spectrometers. In this paper we propose two strategies to improve the performance of the Cherenkov counters which presently use a hydrophilic aerogel radiator, and convey Cherenkov photons towards the photomultipliers by means of mirrors with a parabolic shape in one direction and flat in the other. The first strategy is aerogel baking. In the second strategy we propose a modification of the counter geometry by replacing the mirrors with a planar diffusing surface and by displacing in a different way the photomultipliers. Tests at CERN with a 5 GeV/c multiparticle beam revealed that both the strategies are able to increase significantly the number of the detected Cherenkov photons and, therefore, the detector performan...

  13. Position-sensitive proportional counters using resistance-capacitance position encoding

    International Nuclear Information System (INIS)

    Kopp, M.K.; Borkowski, C.J.

    1975-12-01

    A new method was developed for encoding the position of individual photons, neutrons, or charged particles in proportional counters by using the distributed RC line characteristics of these counters. The signal processing is described and guidelines for the design and operation of these position sensitive proportional counters (PSPCs) are given. Using these guidelines, several prototypic PSPCs were constructed to improve the spatial resolution and shorten the signal processing time; for example, the intrinsic spatial uncertainty was reduced to 28 μ fwhm for alpha particles and 100 μ fwhm for low-energy x rays (2 to 6 keV). Also, the signal processing time was reduced to 0.6 μsec without seriously degrading the spatial resolution. These results have opened new fields of application of the RC position encoding method in imaging distributions of photons, charged particles, or neutrons in nuclear medicine, physics, and radiography

  14. Photon generator

    Science.gov (United States)

    Srinivasan-Rao, Triveni

    2002-01-01

    A photon generator includes an electron gun for emitting an electron beam, a laser for emitting a laser beam, and an interaction ring wherein the laser beam repetitively collides with the electron beam for emitting a high energy photon beam therefrom in the exemplary form of x-rays. The interaction ring is a closed loop, sized and configured for circulating the electron beam with a period substantially equal to the period of the laser beam pulses for effecting repetitive collisions.

  15. Space charge effect in SQS transition in a gas counter

    International Nuclear Information System (INIS)

    Ohgaki, Hideaki; Kametani, Hitoshi; Fujita, Yasuyuki; Uozumi, Yuusuke; Ijiri, Hidenobu; Matoba, Masaru; Sakae, Takeji; Koori, Norihiko

    1990-01-01

    Systematic investigation of the gas multiplication characteristics in the transition region from proportional to SQS mode in a cylindrical proportional counter has been performed. The property of saturation of the gas multiplication factor can be reproduced using the effective electric field which is corrected for the space charge related to the positive ion density in the avalanche. Photon-mediated gas multiplication can explain the large jump phenomenon of the SQS transition. It is shown that the effective electric field in the avalanche becomes almost zero near the anode surface (Meek's streamer condition) at the 50% transition voltage and the region of its maximum moves slightly away from the anode surface. (orig.)

  16. The Eros of Counter Education

    Science.gov (United States)

    Luzon, Pinhas

    2016-01-01

    Erotic Counter Education (ECE) is the educational position of the late Ilan Gur-Ze'ev. In ECE Gur-Ze'ev combines two opposing positions in the philosophy of education, one teleological and anti-utopian, the other teleological and utopian. In light of this unique combination, I ask what mediates between these two poles and suggest that the answer…

  17. Dimensions of Counter-Narratives

    DEFF Research Database (Denmark)

    2019-01-01

    The book welcomes proposals for chapter contributions on a wide array of topics related to the narratological notion of counter-narratives. By way of example, the topic has hitherto been treated by disciplines and subjects such as literature studies, organization studies, corporate communication...

  18. Countering 21st Century Threats

    DEFF Research Database (Denmark)

    Scharling Pedersen, Peter; Pillai, Chad M.; Hun, Lee Jae

    2015-01-01

    ), Counter-Terrorism (CT), and Security and Stability Operations (SSO). • Establishing a construct that allows a strategic Whole-of-Government capacity for operations coordinated by joint interagency task forces. • Continue to developing the Global SOF network. • Increased intelligence sharing in areas...

  19. The Micro Trench Gas Counter

    International Nuclear Information System (INIS)

    Schmitz, J.

    1991-07-01

    A novel design is presented for a gas avalanche chamber with micro-strip gas readout. While existing gaseous microstrip detectors (Micro-strip Gas Counters, Knife edge chambers) have a minimum anode pitch of the order of 100 μm, the pitch of the discussed Micro Trench Gas Counter goes down to 30-50 μm. This leads to a better position resolution and two track separation, and a higher radiation resistivity. Its efficiency and signal speed are expected to be the same as the Microstrip Gas Counter. The energy resolution of the device is expected to be equal to or better than 10 percent for the 55 Fe peak. Since the anode strip dimensions are larger than those in a MSGC, the device may be not as sensitive to discharges and mechanical damage. In this report production of the device is briefly described, and predictions on its operation are made based on electric field calculations and experience with the Microstrip Gas Counter. The authors restrict themselves to the application in High Energy Physics. (author). 10 refs.; 9 figs

  20. Development of a drift tissue equivalent proportional counter for radiation protection personnel dosimetry

    International Nuclear Information System (INIS)

    Bordy, J.M.

    1992-04-01

    A new multicellular geometry for proportional counter has been developed. It is made of several drift regions which are some holes drilled in the cathode in front of anodes wires. The present work is made of 3 parts: 1) A theoretical evaluation of the multicellular counter characteristics: the sensitivity increases by a factor 15 vs the Tinelli Merlin-Gerin counter; the chord length distribution study shows the possibility to use a Dirac function for the dosimetry calculations; a tissue equivalent gas mixture based on argon and propane is designed. 2) The production of a monocellular prototype made of a hole and a needle shaped anode. 3) An experimental study of the prototype electrical characteristics and a computation of the electrical field in the counter. The focalization and the electron drift into the hole, the proportional operating mode are shown. Irradiations in front of photon and neutron sources verify these results

  1. The ARGUS electron/photon calorimeter. Pt. 2

    International Nuclear Information System (INIS)

    Drescher, A.; Graf, H.J.; Graewe, B.; Hofmann, W.; Markees, A.; Matthiesen, U.; Spengler, J.; Wegener, D.

    1983-03-01

    A detailed investigation is described of the photon production and transport in lead scintillator shower counters with wave-length shifter readout built for the ARGUS detector. Experimental data and Monte Carlo calculations are in good agreement. The most prominent effects due to the light collection system are small nonlinearities in the relation between deposited energy and pulse height and an energy dependent decrease of the energy resolution of the counters. (orig.)

  2. Determination of dose equivalent with tissue-equivalent proportional counters

    International Nuclear Information System (INIS)

    Dietze, G.; Schuhmacher, H.; Menzel, H.G.

    1989-01-01

    Low pressure tissue-equivalent proportional counters (TEPC) are instruments based on the cavity chamber principle and provide spectral information on the energy loss of single charged particles crossing the cavity. Hence such detectors measure absorbed dose or kerma and are able to provide estimates on radiation quality. During recent years TEPC based instruments have been developed for radiation protection applications in photon and neutron fields. This was mainly based on the expectation that the energy dependence of their dose equivalent response is smaller than that of other instruments in use. Recently, such instruments have been investigated by intercomparison measurements in various neutron and photon fields. Although their principles of measurements are more closely related to the definition of dose equivalent quantities than those of other existing dosemeters, there are distinct differences and limitations with respect to the irradiation geometry and the determination of the quality factor. The application of such instruments for measuring ambient dose equivalent is discussed. (author)

  3. Basic Research Needs for Countering Terrorism

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, W.; Michalske, T.; Trewhella, J.; Makowski, L.; Swanson, B.; Colson, S.; Hazen, T.; Roberto, F.; Franz, D.; Resnick, G.; Jacobson, S.; Valdez, J.; Gourley, P.; Tadros, M.; Sigman, M.; Sailor, M.; Ramsey, M.; Smith, B.; Shea, K.; Hrbek, J.; Rodacy, P.; Tevault, D.; Edelstein, N.; Beitz, J.; Burns, C.; Choppin, G.; Clark, S.; Dietz, M.; Rogers, R.; Traina, S.; Baldwin, D.; Thurnauer, M.; Hall, G.; Newman, L.; Miller, D.; Kung, H.; Parkin, D.; Shuh, D.; Shaw, H.; Terminello, L.; Meisel, D.; Blake, D.; Buchanan, M.; Roberto, J.; Colson, S.; Carling, R.; Samara, G.; Sasaki, D.; Pianetta, P.; Faison, B.; Thomassen, D.; Fryberger, T.; Kiernan, G.; Kreisler, M.; Morgan, L.; Hicks, J.; Dehmer, J.; Kerr, L.; Smith, B.; Mays, J.; Clark, S.

    2002-03-01

    To identify connections between technology needs for countering terrorism and underlying science issues and to recommend investment strategies to increase the impact of basic research on efforts to counter terrorism.

  4. Quantum photonics

    CERN Document Server

    Pearsall, Thomas P

    2017-01-01

    This textbook employs a pedagogical approach that facilitates access to the fundamentals of Quantum Photonics. It contains an introductory description of the quantum properties of photons through the second quantization of the electromagnetic field, introducing stimulated and spontaneous emission of photons at the quantum level. Schrödinger’s equation is used to describe the behavior of electrons in a one-dimensional potential. Tunneling through a barrier is used to introduce the concept of non­locality of an electron at the quantum level, which is closely-related to quantum confinement tunneling, resonant tunneling, and the origin of energy bands in both periodic (crystalline) and aperiodic (non-crystalline) materials. Introducing the concepts of reciprocal space, Brillouin zones, and Bloch’s theorem, the determination of electronic band structure using the pseudopotential method is presented, allowing direct computation of the band structures of most group IV, group III-V, and group II-VI semiconducto...

  5. Green photonics

    International Nuclear Information System (INIS)

    Quan, Frederic

    2012-01-01

    Photonics, the broad merger of electronics with the optical sciences, encompasses such a wide swath of technology that its impact is almost universal in our everyday lives. This is a broad overview of some aspects of the industry and their contribution to the ‘green’ or environmental movement. The rationale for energy conservation is briefly discussed and the impact of photonics on our everyday lives and certain industries is described. Some opinions from industry are presented along with market estimates. References are provided to some of the most recent research in these areas. (review article)

  6. An introduction to automatic radioactive sample counters

    International Nuclear Information System (INIS)

    1980-01-01

    The subject is covered in chapters, entitled; the detection of radiation in sample counters; nucleonic equipment; liquid scintillation counting; basic features of automatic sample counters; statistics of counting; data analysis; purchase, installation, calibration and maintenance of automatic sample counters. (U.K.)

  7. Counter-discourse in Zimbabwean literature

    NARCIS (Netherlands)

    Mangena, Tendai

    2015-01-01

    Counter-Discourse in Zimbabwean Literature is a study of specific aspects of counter-discursive Zimbabwean narratives in English. In discussing the selected texts, my thesis is based on Terdiman’s (1989) the postcolonial concept of counter-discourse. In Zimbabwean literature challenges to a dominant

  8. Recent results from the DELPHI barrel ring imaging Cherenkov counter

    International Nuclear Information System (INIS)

    Anassontzis, E.G.; Ioannou, P.; Kalkanis, G.; Katsanevas, S.; Kontaxis, I.; Kourkoumelis, C.; Nounos, S.; Preve, P.; Resvanis, L.K.; Brunet, J.M.; Dolbeau, J.; Guglielmo, L.; Ledroit, F.; Poutot, D.; Tristram, G.

    1991-01-01

    The DELPHI detector, installed at LEP, is equipped with RICH (Ring Imaging Cherenkov) counters. The Barrel part incorporates a liquid (C 6 F 14 ) and a gaseous (C 5 F 12 ) radiator providing particle identification up to 20GeV/c. The Cherenkov protons of both radiators are detected by TPC-like photon detectors. The drift gas (75% CH 4 + 25% C 2 H 6 ) is doped with TMAE, but which the UV Cherenkov photons are converted into single free photo-electrons. These are drifted towards MWPC's at the end of the drift tubes and the space coordinates of the conversion point are determined. One half of the Barrel RICH is now equipped with drift tubes and has provided results from the liquid radiator since spring 1990. The gas radiator has been tested with C 2 F 6 as a preliminary filling since August 1990. The data obtained demonstrate the good particle identification potential. For the liquid radiator the number of detected photons per ring in hadron jets is N=8, whereas for muon pairs (single tracks) N=10 has been obtained. For the gas radiator 2.1 photons per track were observed, which demonstrates the good functioning of the focussing mirrors, as the C 2 F 6 this is close to the expected value

  9. Discharge quenching circuit for counters

    International Nuclear Information System (INIS)

    Karasik, A.S.

    1982-01-01

    A circuit for quenching discharges in gas-discharge detectors with working voltage of 3-5 kV based on transistors operating in the avalanche mode is described. The quenching circuit consists of a coordinating emitter follower, amplifier-shaper for avalanche key cascade control which changes potential on the counter electrodes and a shaper of discharge quenching duration. The emitter follower is assembled according to a widely used flowsheet with two transistors. The circuit permits to obtain a rectangular quenching pulse with front of 100 ns and an amplitude of up to 3.2 kV at duration of 500 μm-8 ms. Application of the quenching circuit described permits to obtain countering characteristics with the slope less than or equal to 0.02%/V and plateau extent greater than or equal to 300 V [ru

  10. Counter support for WA35

    CERN Multimedia

    CERN PhotoLab

    1977-01-01

    This assembly was equipped with 78 counters, each consisting of a lucite cone, to produce Cerenkov light, and a CsI scintillator plate of 3 mm thickness glued on the face of the cone. The experiment WA35 was set-up in the s1 beam (West Hall) by the Darmstadt-Heidelberg-Virginia-Warsaw Collaboration to measure angular distributions and multiplicities of pions and recoil protons produced by hadrons interacting in nuclei. (See Annual Report 1976 p. 39)

  11. Photon Differentials

    DEFF Research Database (Denmark)

    Schjøth, Lars; Frisvad, Jeppe Revall; Erleben, Kenny

    2007-01-01

    illumination features. This is often not desirable as these may lose clarity or vanish altogether. We present an accurate method for reconstruction of indirect illumination with photon mapping. Instead of reconstructing illumination using classic density estimation on finite points, we use the correlation...

  12. Photon Rao

    Indian Academy of Sciences (India)

    Volume 2 Issue 5 May 1997 pp 69-72 Feature Article. Molecule of the Month Molecular–Chameleon: Solvatochromism at its Iridescent Best! Photon Rao · More Details Fulltext PDF. Volume 16 Issue 12 December 2011 pp 1303-1306. Molecule of the Month - Molecular-Chameleon: Solvatochromism at its Iridescent Best!

  13. INTRODUCING OVER THE COUNTER COUNSELING

    Directory of Open Access Journals (Sweden)

    Nataša Bakić-Mirić

    2009-01-01

    Full Text Available A pharmacist in today’s world has a great responsibility – to help and educate patients about diverse ways for effective self-treatment. Whereas self-care is becoming increasingly popular among patients today the availability of over-the-counter medications makes it possible for patients to treat numerous conditions on their own but still under the supervision of a healthcare provider. During the pharmacist-patient encounter, the pharmacist’s obligation is to evaluate the patient’s medical condition, provide proper advice and counsel the patient on the proper course of treatment to be taken. Also by employing effective over the counter (OTC counseling as the most proper means in a pharmacist/patient communication process and, accordingly, rapport building in the OTC area, the pharmacist needs to demonstrate high energy, enthusiasm, respect, empathy, know-how of sensitive intercultural issues alongside personal appearance, body language, eye contact that all together make his/her personal “signature”. Accordingly, apart from patient education, the primary objective of OTC counseling becomes to educate pharmacists on basic principles used in assisting patients in the selection of over-the-counter (OTC products, provide examples of proper communication techniques for effective patient counseling concerning the OTC products (i.e. dosage, administration technique, storage, food and beverage interaction, monitoring etc where the pharmacist plays the key role in helping patients maximize their pharmaceutical care.

  14. Position-sensitive proportional counter

    International Nuclear Information System (INIS)

    Kopp, M.K.

    1980-01-01

    A position-sensitive proportional counter circuit uses a conventional (low-resistance, metal-wire anode) counter for spatial resolution of an ionizing event along the anode, which functions as an RC line. A pair of preamplifiers at the anode ends act as stabilized active-capacitance loads, each comprising a series-feedback, low-noise amplifier and a unity-gain, shunt-feedback amplifier whose output is connected through a feedback capacitor to the series-feedback amplifier input. The stabilized capacitance loading of the anode allows distributed RC-line position encoding and subsequent time difference decoding by sensing the difference in rise times of pulses at the anode ends where the difference is primarily in response to the distributed capacitance along the anode. This allows the use of lower resistance wire anodes for spatial radiation detection which simplifies the counter construction of handling of the anodes, and stabilizes the anode resistivity at high count rates (>10 6 counts/sec). (author)

  15. The bremsstrahlung tagged photon beam in Hall B at JLab

    CERN Document Server

    Sober, D I; Longhi, A; Matthews, S K; O'Brien, J T; Berman, B L; Briscoe, W J; Cole, P L; Connelly, J P; Dodge, W R; Murphy, L Y; Philips, S A; Dugger, M K; Lawrence, D; Ritchie, B G; Smith, E S; Lambert, J M; Anciant, E; Audit, G; Auger, T; Marchand, C; Klusman, M; Napolitano, J; Khandaker, M A; Salgado, C W; Sarty, A J

    2000-01-01

    We describe the design and commissioning of the photon tagging beamline installed in experimental Hall B at the Thomas Jefferson National Accelerator Facility (JLab). This system can tag photon energies over a range from 20% to 95% of the incident electron energy, and is capable of operation with beam energies up to 6.1 GeV. A single dipole magnet is combined with a hodoscope containing two planar arrays of plastic scintillators to detect energy-degraded electrons from a thin bremsstrahlung radiator. The first layer of 384 partially overlapping small scintillators provides photon energy resolution, while the second layer of 61 larger scintillators provides the timing resolution necessary to form a coincidence with the corresponding nuclear interaction triggered by the tagged photon. The definitions of overlap channels in the first counter plane and of geometric correlation between the two planes are determined using digitized time information from the individual counters. Auxiliary beamline devices are briefl...

  16. Intercalibration of CDTN and IRD whole body counters

    International Nuclear Information System (INIS)

    Dantas, B.M.; Dantas, A.L.A.; Alonso, T.C.

    2008-01-01

    Full text: Intercalibration exercises are designed to harmonize analytical techniques and ensure reliability of measurement results performed in a laboratory network. Such strategy helps to improve laboratory performance among participants in future intercomparison exercises, when it is verified the metrological capacity, by determining accuracy, precision and reproducibility of data produced by each laboratory. In Brazil, there are currently four in vivo monitoring systems, located in IRD, in Rio de Janeiro, CDTN, in Belo Horizonte, IPEN, in Sao Paulo and CNAAA, in Angra dos Reis. Such systems, generically referred as whole body counters, aim to detect and quantify radionuclides in organs and tissues for radiological protection purposes and to provide useful information for studies on biokinetic behavior of radionuclides in humans and animals. The objective of this work is to establish a methodology to be applied for intercalibration of whole body counters. The IRD whole body counter is installed in a 15 cm steel shielded room where two NaI(Tl) and four HPGe detectors are calibrated for the determination of radionuclides in the energy range from 10 to 3000 keV. The CDTN whole body counter has one NaI detector set up in a shadow shield configuration, and is able to determine radionuclides emitting photons from 100 to 2000 keV. The intercalibration exercise described in this work was planed for whole body geometry using the scintillation detectors available in both laboratories. It was used a thin glass vial containing 2,6615 g of a solution of four gamma emitters ( 57 Co, 137 Cs, 54 Mn, 65 Zn), supplied by the National Laboratory for Metrology of Ionizing Radiation (LNMRI-IRD). The glass vial was measured in the same geometry in both IRD and CDTN whole body counters, being positioned at 31,5 cm distance from the NaI(Tl) detector of each laboratory. The calibration curves (photo peak channel and Efficiency vs Energy) of each detection system were compared. The

  17. Proportional counter system for radiation measurement

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, M; Okudera, S

    1970-11-21

    A gas such as Xe or Kr employed in counter tubes is charged into the counter tube of a gas-flow type proportional counter for radiation measurement and into a vessel having a volume larger than that of the counter tube. The vessel communicates with the counter tube to circulate the gas via a pump through both the vessel and tube during measurement. An organic film such as a polyester synthetic resin film is used for the window of the counter tube to measure X-rays in the long wavelength range. Accordingly, a wide range of X-rays can be measured including both long and short wavelengths ranges by utilizing only one counter tube, thus permitting the gases employed to be effectively used.

  18. Photon Collider Physics with Real Photon Beams

    International Nuclear Information System (INIS)

    Gronberg, J; Asztalos, S

    2005-01-01

    Photon-photon interactions have been an important probe into fundamental particle physics. Until recently, the only way to produce photon-photon collisions was parasitically in the collision of charged particles. Recent advances in short-pulse laser technology have made it possible to consider producing high intensity, tightly focused beams of real photons through Compton scattering. A linear e + e - collider could thus be transformed into a photon-photon collider with the addition of high power lasers. In this paper they show that it is possible to make a competitive photon-photon collider experiment using the currently mothballed Stanford Linear Collider. This would produce photon-photon collisions in the GeV energy range which would allow the discovery and study of exotic heavy mesons with spin states of zero and two

  19. Novel determination of protein, fat, and lactose of milk by liquid scintillation counter

    International Nuclear Information System (INIS)

    Noble, R.C.; Shand, J.H.; West, I.G.

    1981-01-01

    A method for routine determination of protein, fat, and lactose contents of milk is based on the ability of a scintillation counter to measure coloration or opalescence through attenuation of photons emitted from sealed miniature carbon-14 and hydrogen-3 radioactive standards. A series of simplified and accurate analytical procedures enable full advantage to be taken of the automatic facilities on the modern liquid scintillation counter. The methods provide several advantages over existing procedures. Accuracy of quantification was high as assessed by comparing the results with those derived by recommended Kjeldahl, Gerber, and colorimetric procedures for protein, fat, and lactose determinations, respectively

  20. Improvements to well scintillation counters

    International Nuclear Information System (INIS)

    Farukhi, M.R.; Mataraza, G.A.; Wimer, O.D.

    1977-01-01

    This invention relates to the field of ionising radiation detection. It concerns in particular scintillation detectors of the type that is commonly used in conjunction with a photomultiplier tube and that is used for monitoring radiation, for instance in the clinical measurements of isotopes. This invention enables well scintillation counters to be made, characterised by a high efficiency in measuring the thindown rate of radio-pharmaceutical solutions and to resolve the distribution of energy emanating from the radioactive source. It particularly consists in improving the uniformity of the luminous efficiency, the quality of the resolution and the efficiency whilst improving the reception of light [fr

  1. Programmable spark counter of tracks

    International Nuclear Information System (INIS)

    Denisov, A.E.; Nikolaev, V.A.; Vorobjev, I.B.

    2005-01-01

    For the purpose, a new set-the programmable all-automatic spark counter AIST-4-has been developed and manufactured. Compared to our previous automated spark counter ISTRA, which was operated by the integrated fixed program, the new set is operated completely by a personal computer. The mechanism for pressing and pulling the aluminized foil is put into action by a step motor operated by a microcontroller. The step motor turns an axle. The axle has two eccentrics. One of them moves a pressing plate up and down. The second eccentric moves the aluminized foil by steps of ∼15mm after the end of each pulse counting. One turnover of the axle corresponds to one pulse count cycle. The step motor, the high-voltage block and the pulse count block are operated by the microcontroller PIC 16C84 (Microstar). The set can be operated either manually by keys on the front panel or by a PC using dialogue windows for radon or neutron measurements (for counting of alpha or fission fragment tracks). A number of algorithms are developed: the general procedures, the automatic stopping of the pulse counting, the calibration curve, determination of the count characteristics and elimination of the short circuit in a track

  2. A low-level needle counter

    International Nuclear Information System (INIS)

    Fujita, Y.; Taguchi, Y.; Imamura, M.; Inoue, T.; Tanaka, S.

    1977-01-01

    A small end-window type gas-flow counter which has a sharpened needle (anode) against the end-window plane (cathode) was developed for low-level counting of β particles to the amount of less than one count per hour in solid sources of relatively high specific activity. The advantage of the needle counter for low-level work is that being of a conical shape the active volume as against the window area is small. The background count rate of 0.0092+-0.0005 cpm was obtained for a 10 mm dia needle counter operating in GM mode and in anticoincidence with a well-type NaI(Tl) guard crystal with massive shields. The counter design and the counter characteristics are presented in detail. The needle counter is simple in design, low-cost and stable in long time operation. (author)

  3. Counter Traction Makes Endoscopic Submucosal Dissection Easier

    OpenAIRE

    Oyama, Tsuneo

    2012-01-01

    Poor counter traction and poor field of vision make endoscopic submucosal dissection (ESD) difficult. Good counter traction allows dissections to be performed more quickly and safely. Position change, which utilizes gravity, is the simplest method to create a clear field of vision. It is useful especially for esophageal and colon ESD. The second easiest method is clip with line method. Counter traction made by clip with line accomplishes the creation of a clear field of vision and suitable co...

  4. Crate counter for normal operating loss

    International Nuclear Information System (INIS)

    Harlan, R.A.

    A lithium-loaded zinc sulfide scintillation counter to closely assay plutonium in waste packaged in 1.3 by 1.3 by 2.13m crates was built. In addition to assays for normal operating loss accounting, the counter will allow safeguards verification immediately before shipment of the crates for burial. The counter should detect approximately 10 g of plutonium in 1000 kg of waste

  5. Photon absorptiometry

    International Nuclear Information System (INIS)

    Valkema, R.; Blokland, J.A.K.; Papapoulos, S.E.; Bijvoet, O.L.M.; Pauwels, E.K.J.

    1989-01-01

    Osteoporosis is a significant health problem in the western world, with important medical, social and economical consequences. Prevention and treatment require reliable methods for in vivo monitoring of the bone mineral content (BMC) and its change in time. This paper presents an overview of currently used radiological methods, based on photon absorptiometry, and their clinical applications. With recent methods based on dual energy X-ray absorptiometry accurate and precise measurements of axial BMC can be obtained. Whether this improvements allows reliable detection of small changes in BMC remains to be investigated. (Author). 95 refs.; 1 tab

  6. The 'miniskirt' counter array at CDF II

    International Nuclear Information System (INIS)

    Artikov, A.; Budagov, Yu.; Bellettini, G.

    2002-01-01

    Muon detection is fundamental to many of the interesting analyses at CDF II. For more efficient muon registration in Run II it was decided to increase geometrical coverage. The so-called 'miniskirt' counters are part of this upgrade. The original design parameters of the 'miniskirt' and mixed 'miniskirt' scintillation counters for the CDF Muon System are presented. The modifications, testing and installation of these counters within the CDF Upgrade Project are described in detail. The timing characteristics of mixed 'miniskirt' counters are also investigated using cosmic muons. The measurements show that the time resolution does not exceed 2.2 ns

  7. Prototype of IGZO-TFT preamplifier and analog counter for pixel detector

    International Nuclear Information System (INIS)

    Shimazoe, K.; Koyama, A.; Takahashi, H.; Shindoh, T.; Miyoshi, H.

    2017-01-01

    IGZO-TFT (Indium Galium Zinc Oxide-Thin Film Transistor) is a promising technology for controlling large display areas and large area sensors because of its very low leakage current in the off state and relatively low cost. IGZO has been used as a switching gate for a large area flat-panel detector. The photon counting capability for X-ray medical imaging has been investigated and expected for low-dose exposure and material determination. Here the design and fabrication of a charge sensitive preamplifier and analog counter using IGZO-TFT processes and its performance are reported for the first time to be used for radiation photon counting applications.

  8. X-ray polarimetry with a conventional gas proportional counter through rise-time analysis

    CERN Document Server

    Hayashida, K; Tsunemi, H; Torii, K; Murakami, H; Ohno, Y; Tamura, K

    1999-01-01

    We have performed an experiment on the signal rise time of a Xe gas proportional counter using a polarized X-ray beam of synchrotron orbital radiation with energies from 10 to 40 keV. When the counter anode is perpendicular to the electric vector of the incident X-ray photons, the average rise time becomes significantly longer than that for the parallel case. This indicates that the conventional gas proportional counters are useful for X-ray polarimetry. The moderate modulation contrast of this rise-time polarimeter (M=0.1 for 10 keV X-rays and M=0.35 for 40 keV X-rays), with capability of the simultaneous measuring X-ray energies and the timing, would be useful for applications in X-ray astronomy and in other fields.

  9. Quantum non-demolition phonon counter with a hybrid optomechnical system

    Science.gov (United States)

    Song, Qiao; Zhang, KeYe; Dong, Ying; Zhang, WeiPing

    2018-05-01

    A phonon counting scheme based on the control of polaritons in an optomechanical system is proposed. This approach permits us to measure the number of phonons in a quantum non-demolition (QND) manner for arbitrary modes not limited by the frequency matching condition as in usual photon-phonon scattering detections. The performance on phonon number transfer and quantum state transfer of the counter are analyzed and simulated numerically by taking into account all relevant sources of noise.

  10. Numerical model of thyroid counter

    Directory of Open Access Journals (Sweden)

    Szuchta Maciej

    2016-03-01

    Full Text Available The aim of this study was to develop a numerical model of spectrometric thyroid counter, which is used for the measurements of internal contamination by in vivo method. The modeled detector is used for a routine internal exposure monitoring procedure in the Radiation Protection Measurements Laboratory of National Centre for Nuclear Research (NCBJ. This procedure may also be used for monitoring of occupationally exposed nuclear medicine personnel. The developed model was prepared using Monte Carlo code FLUKA 2011 ver. 2b.6 Apr-14 and FLAIR ver. 1.2-5 interface. It contains a scintillation NaI(Tl detector, the collimator and the thyroid water phantom with a reference source of iodine 131I. The geometry of the model was designed and a gamma energy spectrum of iodine 131I deposited in the detector was calculated.

  11. Evaluation of waste crate counter

    International Nuclear Information System (INIS)

    Wachter, J.R.; Shaw, S.W.

    1994-01-01

    A novel nondestructive measurement system has been developed to perform combined gamma-ray, passive neutron, and active neutron analyses of radioactive waste packaged in large crates. The system will be used to examine low level and transuranic waste at the Waste Receiving and Processing facility at Westinghouse-Hanford Corp. Prior to delivery of the system, an extensive evaluation of its performance characteristics will be conducted. The evaluation is to include an assessment of the mechanical properties of the system, gamma-ray attenuation correction algorithms, instrument response as a function of source positions, performance of the high resolution gamma-ray detector for ''hot spot'' and isotopic analyses, active and passive neutron counter response, instrument sensitivity, matrix effects, and packaging effects. This report will discuss the findings of the evaluation program, to date, and indicate future directions for the program

  12. Characterization of Sphinx1 ASIC X-ray detector using photon counting and charge integration

    Science.gov (United States)

    Habib, A.; Arques, M.; Moro, J.-L.; Accensi, M.; Stanchina, S.; Dupont, B.; Rohr, P.; Sicard, G.; Tchagaspanian, M.; Verger, L.

    2018-01-01

    Sphinx1 is a novel pixel architecture adapted for X-ray imaging, it detects radiation by photon counting and charge integration. In photon counting mode, each photon is compensated by one or more counter-charges typically consisting of 100 electrons (e-) each. The number of counter-charges required gives a measure of the incoming photon energy, thus allowing spectrometric detection. Pixels can also detect radiation by integrating the charges deposited by all incoming photons during one image frame and converting this analog value into a digital response with a 100 electrons least significant bit (LSB), based on the counter-charge concept. A proof of concept test chip measuring 5 mm × 5 mm, with 200 μm × 200 μm pixels has been produced and characterized. This paper provides details on the architecture and the counter-charge design; it also describes the two modes of operation: photon counting and charge integration. The first performance measurements for this test chip are presented. Noise was found to be ~80 e-rms in photon counting mode with a power consumption of only 0.9 μW/pixel for the static analog part and 0.3 μW/pixel for the static digital part.

  13. The GlueX Start Counter and Beam Asymmetry$\\Sigma$ in Single $\\pi^{0}$ Photoproduction

    Energy Technology Data Exchange (ETDEWEB)

    Pooser, Eric [Florida Intl Univ., Miami, FL (United States)

    2016-03-26

    The GlueX experiment aims to study meson photoproduction while utilizing the coherent bremsstrahlung technique to produce a 9 GeV linearly polarized photon beam incident on a liquid H2 target. A Start Counter detector was fabricated to properly identify the accelerator electron beam buckets and to provide accurate timing information. The Start Counter detector was designed to operate at photon intensities of up to 108 γ/s in the coherent peak and provides a timing resolution ~300 ps so as to provide successful identification of the electron beam buckets to within 99% accuracy. Furthermore, the Start Counter detector provides excellent solid angle coverage, ~ 90% of 4π hermeticity, and a high degree of segmentation for background rejection. It consists of a cylindrical array of 30 scintillators with pointed ends that bend towards the beam at the downstream end. Magnetic field insensitive silicon photomultiplier detectors were selected as the readout system. An initial measurement of the beam asymmetry Sigma in the exclusive reaction γ$\\vec{p}$→ π0p, where π0 → γ has been carried out utilizing the GlueX spectrometer during the Spring 2015 commissioning run. The tagged photon energies ranged from 2.5≤ Eγ ≤ 3.0 GeV in the coherent peak. These measurements were then compared to the world data set and show remarkable agreement with only two hours of physics production running.

  14. On generating counter-rotating streamwise vortices

    KAUST Repository

    Winoto, S H

    2015-09-23

    Counter-rotating streamwise vortices are known to enhance the heat transfer rate from a surface and also to improve the aerodynamic performance of an aerofoil. In this paper, some methods to generate such counter-rotating vortices using different methods or physical conditions will be briefly considered and discussed.

  15. Charged particle identification: Cherenkov counters at ISABELLE

    International Nuclear Information System (INIS)

    Etkin, A.; Kostoulas, I.; Leith, D.W.G.S.; Thun, R.

    1977-01-01

    A brief summary is given of a study of Cherenkov counters for ISABELLE. The study was certainy not exhaustive and was meant primarily to suggest future detector development. A substantial research effort is needed in order to insure that Cherenkov counters utilizing photoionization are fully exploited

  16. On generating counter-rotating streamwise vortices

    KAUST Repository

    Winoto, S H; Mitsudharmadi, Hatsari; Budiman, A C; Hasheminejad, S M; Nadesan, T; Tandiono; Low, H T; Lee, T S

    2015-01-01

    Counter-rotating streamwise vortices are known to enhance the heat transfer rate from a surface and also to improve the aerodynamic performance of an aerofoil. In this paper, some methods to generate such counter-rotating vortices using different methods or physical conditions will be briefly considered and discussed.

  17. Physics at high energy photon photon colliders

    International Nuclear Information System (INIS)

    Chanowitz, M.S.

    1994-06-01

    I review the physic prospects for high energy photon photon colliders, emphasizing results presented at the LBL Gamma Gamma Collider Workshop. Advantages and difficulties are reported for studies of QCD, the electroweak gauge sector, supersymmetry, and electroweak symmetry breaking

  18. Resonance formation in photon-photon collisions

    International Nuclear Information System (INIS)

    Gidal, G.

    1988-08-01

    Recent experimental progress on resonance formation in photon-photon collisions is reviewed with particular emphasis on the pseudoscalar and tensor nonents and on the γγ* production of spin-one resonances. 37 refs., 17 figs., 5 tabs

  19. Direct Characterization of Ultrafast Energy-Time Entangled Photon Pairs.

    Science.gov (United States)

    MacLean, Jean-Philippe W; Donohue, John M; Resch, Kevin J

    2018-02-02

    Energy-time entangled photons are critical in many quantum optical phenomena and have emerged as important elements in quantum information protocols. Entanglement in this degree of freedom often manifests itself on ultrafast time scales, making it very difficult to detect, whether one employs direct or interferometric techniques, as photon-counting detectors have insufficient time resolution. Here, we implement ultrafast photon counters based on nonlinear interactions and strong femtosecond laser pulses to probe energy-time entanglement in this important regime. Using this technique and single-photon spectrometers, we characterize all the spectral and temporal correlations of two entangled photons with femtosecond resolution. This enables the witnessing of energy-time entanglement using uncertainty relations and the direct observation of nonlocal dispersion cancellation on ultrafast time scales. These techniques are essential to understand and control the energy-time degree of freedom of light for ultrafast quantum optics.

  20. Silicon photomultiplier as a detector of Cherenkov photons

    International Nuclear Information System (INIS)

    Korpar, S.; Dolenec, R.; Hara, K.; Iijima, T.; Krizan, P.; Mazuka, Y.; Pestotnik, R.; Stanovnik, A.; Yamaoka, M.

    2008-01-01

    A novel photon detector-i.e. the silicon photomultiplier-whose main advantage over conventional photomultiplier tubes is the operation in high magnetic fields, has been tested as a photon detector in a proximity focusing RICH with aerogel radiator. This type of RICH counter is proposed for the upgrade of the Belle detector at the KEK B-factory. Recently produced silicon photomultipliers show less noise and have larger size, which are important issues for a large area photon detector. We measured the single photon pulse height distribution, the timing resolution and the position sensitivity for different silicon photomultipliers (Hamamatsu MPPC HC025, HC050, and HC100). The silicon photomultipliers were then used to detect Cherenkov photons emitted by cosmic ray particles in a proximity focusing aerogel RICH. Various light guides were investigated in order to increase the detection efficiency

  1. Counter traction makes endoscopic submucosal dissection easier.

    Science.gov (United States)

    Oyama, Tsuneo

    2012-11-01

    Poor counter traction and poor field of vision make endoscopic submucosal dissection (ESD) difficult. Good counter traction allows dissections to be performed more quickly and safely. Position change, which utilizes gravity, is the simplest method to create a clear field of vision. It is useful especially for esophageal and colon ESD. The second easiest method is clip with line method. Counter traction made by clip with line accomplishes the creation of a clear field of vision and suitable counter traction thereby making ESD more efficient and safe. The author published this method in 2002. The name ESD was not established in those days; the name cutting endoscopic mucosal resection (EMR) or EMR with hook knife was used. The other traction methods such as external grasping forceps, internal traction, double channel scope, and double scopes method are introduced in this paper. A good strategy for creating counter traction makes ESD easier.

  2. Aerogel Cherenkov Counters of the KEDR Detector

    CERN Document Server

    Ovtin, I V; Barnyakov, M Y; Bobrovnikov, V S; Buzykaev, A R; Danilyuk, A F; Katcin, A A; Kononov, S A; Kravchenko, E A; Kuyanov, I A; Onuchin, A P; Rodiakin, V A

    2017-01-01

    The particle identification system of the KEDR detector is based on aerogel threshold Cherenkov counters called ASHIPH counters. The system consists of 160 counters arranged in two layers. An event reconstruction program for the ASHIPH system was developed. The position of each counter relative to the tracking system was determined using cosmic muons and Bhabha events. The geometric efficiency of the ASHIPH system was verified with Bhabha events. The efficiency of relativistic particle detection was measured with cosmic muons. A π/K separation of 4δ in the momentum range 0.95 −1.45 GeV/c was confirmed. A simulation program for the ASHIPH counters has been developed.

  3. Non-Imaging Detectors and Counters. Chapter 10

    Energy Technology Data Exchange (ETDEWEB)

    Zanzonico, P. B. [Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York (United States)

    2014-12-15

    Historically, nuclear medicine has been largely an imaging based specialty, employing such diverse and increasingly sophisticated modalities as rectilinear scanning, (planar) gamma camera imaging, single photon emission computed tomography (SPECT) and positron emission tomography (PET). Non-imaging radiation detection, however, remains an essential component of nuclear medicine. This chapter reviews the operating principles, performance, applications and quality control (QC) of the various non-imaging radiation detection and measurement devices used in nuclear medicine, including survey meters, dose calibrators, well counters, intra-operative probes and organ uptake probes. Related topics, including the basics of radiation detection, statistics of nuclear counting, electronics, generic instrumentation performance parameters and nuclear medicine imaging devices, are reviewed in depth in other chapters of this book.

  4. The performance of photon counting imaging with a Geiger mode silicon avalanche photodiode

    International Nuclear Information System (INIS)

    Qu, Hui-Ming; Zhang, Yi-Fan; Ji, Zhong-Jie; Chen, Qian

    2013-01-01

    In principle, photon counting imaging can detect a photon. With the development of low-level-light image intensifier techniques and low-level-light detection devices, photon counting imaging can now detect photon images under extremely low illumination. Based on a Geiger mode silicon avalanche photodiode single photon counter, an experimental system for photon counting imaging was built through two-dimensional scanning of a SPAD (single photon avalanche diode) detector. The feasibility of the imaging platform was validated experimentally. Two images with different characteristics, namely, the USAF 1951 resolution test panel and the image of Lena, were chosen to evaluate the imaging performance of the experimental system. The results were compared and analysed. The imaging properties under various illumination and scanning steps were studied. The lowest illumination limit of the SPAD photon counting imaging was determined. (letter)

  5. Hadron production in photon-photon collisions

    International Nuclear Information System (INIS)

    Pandita, P.N.; Singh, Y.

    1976-01-01

    We analyze deep-inelastic photon-photon collisions via the two-photon mechanism in electron-positron (-electron) colliding beams in a form especially suitable for experimental analysis. It is shown that by a helicity analysis similar to that used in electroproduction experiments, we can separate five of the eight structure functions describing the process γ* + γ* → hadrons. The helicity cross sections for this process and for the process with one real photon (inelastic electron-photon scattering) are related to structure functions, and are evaluated using quark light-cone algebra. There are anomalous contributions to the structure functions for the inelastic electron-photon scattering which arise both in parton as well as generalized vector-meson-dominance models. This suggests a connection between these two types of models for photon-photon scattering. Further, we use vector-meson dominance to construct a sum rule for sigma/sub gamma//sub gamma/ /sub arrow-right/ from which it is estimated that roughly 20% of the cross section should be built up from higher-mass vector states. Using a spectral representation for the total transverse cross section, and the ''aligned-jet'' vector-dominance model we achieve a connection, via a ''correspondence principle,'' with the parton model for the hadron multiplicities in photon-photon collisions. We also comment on inclusive pion multiplicities and the approach to scaling for photon-photon processes in the light-cone algebra

  6. Propagation velocity of an avalanche along the anode wire in a Geiger-Mueller counter filled with Q-gas at 1 ATM

    International Nuclear Information System (INIS)

    Matsuda, Kazunori; Sanada, Junpei

    1990-01-01

    Simple methods were applied to investigate the characteristics of a Geiger-Mueller counter with Q-gas flowing at 1 atm. The propagation velocity of the photon-aided avalanche along the anode wire depends linearly on the strength of the electric field in the counter. Its fluctuation (FWHM) as a function of distance between the source position and the end point is discussed. (orig.)

  7. Secured Optical Communications Using Quantum Entangled Two-Photon Transparency Modulation

    Science.gov (United States)

    Kojima, Jun (Inventor); Nguyen, Quang-Viet (Inventor); Lekki, John (Inventor)

    2015-01-01

    A system and method is disclosed wherein optical signals are coded in a transmitter by tuning or modulating the interbeam delay time (which modulates the fourth-order coherence) between pairs of entangled photons. The photon pairs are either absorbed or not absorbed (transparent) by an atomic or molecular fluorescer in a receiver, depending on the inter-beam delay that is introduced in the entangled photon pairs. Upon the absorption, corresponding fluorescent optical emissions follow at a certain wavelength, which are then detected by a photon detector. The advantage of the disclosed system is that it eliminates a need of a coincidence counter to realize the entanglement-based secure optical communications because the absorber acts as a coincidence counter for entangled photon pairs.

  8. Aerogel Cerenkov counters at DESY

    International Nuclear Information System (INIS)

    Poelz, G.

    1984-11-01

    In high energy physics it is common to identify a charged particle and its kinematical parameters by the measurement of its momentum and its velocity. Cerenkov detectors have developed into a standard tool because they operate in the γ = (1-β 2 )sup(-1/2) range from about 1 to 100 which is not easily accessible by other devices. Pions, kaons and protons in present high energy experiments reach energies of several GeV. Threshold Cerenkov detectors for these particles need indices of refraction below 1.1 which are often produced with gases under high pressure. The design for chambers operating in this region was drasticly simplified when porous materials serving as Cerenkov radiators were invented. These chambers complement the time-of-flight counters, which cover the low energy region. Aerogel of silica is up to now the only porous substance with sufficient optical transparency. Its quality has been improved substantially in recent times so that large size detectors can be constructed. (orig.)

  9. Counter-diabatic driving for Dirac dynamics

    Science.gov (United States)

    Fan, Qi-Zhen; Cheng, Xiao-Hang; Chen, Xi

    2018-03-01

    In this paper, we investigate the fast quantum control of Dirac equation dynamics by counter-diabatic driving, sharing the concept of shortcut to adiabaticity. We systematically calculate the counter-diabatic terms in different Dirac systems, like graphene and trapped ions. Specially, the fast and robust population inversion processes are achieved in Dirac system, taking into account the quantum simulation with trapped ions. In addition, the population transfer between two bands can be suppressed by counter-diabatic driving in graphene system, which might have potential applications in opt-electric devices.

  10. 21 CFR 866.2170 - Automated colony counter.

    Science.gov (United States)

    2010-04-01

    ...) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2170 Automated colony counter. (a) Identification. An automated colony counter is a mechanical device intended for medical...

  11. Photonic time crystals.

    Science.gov (United States)

    Zeng, Lunwu; Xu, Jin; Wang, Chengen; Zhang, Jianhua; Zhao, Yuting; Zeng, Jing; Song, Runxia

    2017-12-07

    When space (time) translation symmetry is spontaneously broken, the space crystal (time crystal) forms; when permittivity and permeability periodically vary with space (time), the photonic crystal (photonic time crystal) forms. We proposed the concept of photonic time crystal and rewritten the Maxwell's equations. Utilizing Finite Difference Time Domain (FDTD) method, we simulated electromagnetic wave propagation in photonic time crystal and photonic space-time crystal, the simulation results show that more intensive scatter fields can obtained in photonic time crystal and photonic space-time crystal.

  12. Anomalous transparency in photonic crystals and its application to point-by-point grating inscription in photonic crystal fibers.

    Science.gov (United States)

    Baghdasaryan, Tigran; Geernaert, Thomas; Chah, Karima; Caucheteur, Christophe; Schuster, Kay; Kobelke, Jens; Thienpont, Hugo; Berghmans, Francis

    2018-04-03

    It is common belief that photonic crystals behave similarly to isotropic and transparent media only when their feature sizes are much smaller than the wavelength of light. Here, we counter that belief and we report on photonic crystals that are transparent for anomalously high normalized frequencies up to 0.9, where the crystal's feature sizes are comparable with the free space wavelength. Using traditional photonic band theory, we demonstrate that the isofrequency curves can be circular in the region above the first stop band for triangular lattice photonic crystals. In addition, by simulating how efficiently a tightly focused Gaussian beam propagates through the photonic crystal slab, we judge on the photonic crystal's transparency rather than on isotropy only. Using this approach, we identified a wide range of photonic crystal parameters that provide anomalous transparency. Our findings indicate the possibility to scale up the features of photonic crystals and to extend their operational wavelength range for applications including optical cloaking and graded index guiding. We applied our result in the domain of femtosecond laser micromachining, by demonstrating what we believe to be the first point-by-point grating inscribed in a multi-ring photonic crystal fiber.

  13. Development of DIRC counters for the PANDA experiment at FAIR

    International Nuclear Information System (INIS)

    Seitz, B.; Bettoni, D.; Branford, D.; Britting, A.; Carassiti, V.; Cecchi, A.; Cowie, E.; Dodokhof, V.Kh.; Dueren, M.; Eyrich, W.; Foehl, K.; Hayrapetyan, A.; Hill, G.; Hoek, M.; Hohler, R.; Kaiser, R.; Keri, T.; Lehmann, A.; Lehmann, D.; Marton, J.

    2011-01-01

    The PANDA experiment at the planned FAIR facility at GSI, Darmstadt, aims at measuring hadronic final states with unprecedented precision and luminosity. Superior particle identification of charged and neutral particles is mandatory to fulfil PANDA's physics aims. DIRC (Detection of Internally Reflected Cherenkov light) counters are foreseen for charged particle identification. A barrel DIRC will cover the central region while a disc DIRC will provide particle identification in the forward region. Three DIRC concepts differing in the radiator geometry and method for dispersion correction are studied. The barrel DIRC uses a novel imaging system and aims at exploiting a 3D reconstruction to mitigate dispersion effects. Two concepts are investigated for the forward disc DIRC. One concept employs passive dispersion correction and focussing light guides for image reconstruction. Alternatively, time-of-propagation measurements and a wave-length dependent photon detection system are investigated. The three detector designs share common developments such as investigating radiator properties and photon detection systems, and use the same test beam facilities.

  14. Photon-Photon Collisions -- Past and Future

    International Nuclear Information System (INIS)

    Brodsky, Stanley J.

    2005-01-01

    I give a brief review of the history of photon-photon physics and a survey of its potential at future electron-positron colliders. Exclusive hadron production processes in photon-photon and electron-photon collisions provide important tests of QCD at the amplitude level, particularly as measures of hadron distribution amplitudes. There are also important high energy γγ and eγ tests of quantum chromodynamics, including the production of jets in photon-photon collisions, deeply virtual Compton scattering on a photon target, and leading-twist single-spin asymmetries for a photon polarized normal to a production plane. Since photons couple directly to all fundamental fields carrying the electromagnetic current including leptons, quarks, W's and supersymmetric particles, high energy γγ collisions will provide a comprehensive laboratory for Higgs production and exploring virtually every aspect of the Standard Model and its extensions. High energy back-scattered laser beams will thus greatly extend the range of physics of the International Linear Collider

  15. The counter ion: expanding excipient functionality

    Directory of Open Access Journals (Sweden)

    Shireesh Apte

    2011-06-01

    Full Text Available Excipients have increasingly become 'enablers' of drug delivery and efficacy rather than passive bystanders. Advances in pharmaceutical technology have enabled the ability to deliver specific counter ions (in the form of the counter ion containing excipient and the API simultaneously to preselected targets in the body. This, coupled with a near universal mechanism of columbic interactions that determine the [API- counter ion] efficacy, can be harnessed to exploit this hitherto unavailable or unrecognized enabling mechanism. New excipients may be assembled by a near inexhaustible supply of different permutations of counter ions and their judicious use in specific situations could potentially drive a renaissance in excipient innovation (and drug delivery and efficacy despite regulatory stagnation.

  16. Geometric covers, graph orientations, counter games

    DEFF Research Database (Denmark)

    Berglin, Edvin

    -directed graph is dynamic (can be altered by some outside actor), some orientations may need to be reversed in order to maintain the low out-degree. We present a new algorithm that is simpler than earlier work, yet matches or outperforms the efficiency of these results with very few exceptions. Counter games...... example is Line Cover, also known as Point-Line Cover, where a set of points in a geometric space are to be covered by placing a restricted number of lines. We present new FPT algorithms for the sub-family Curve Cover (which includes Line Cover), as well as for Hyperplane Cover restricted to R 3 (i...... are a type of abstract game played over a set of counters holding values, and these values may be moved between counters according to some set of rules. Typically they are played between two players: the adversary who tries to concentrate the greatest value possible in a single counter, and the benevolent...

  17. Count rate effect in proportional counters

    International Nuclear Information System (INIS)

    Bednarek, B.

    1980-01-01

    A critical evaluaton is presented of the actual state of investigations and explanations of the resolution and pulse height changes resulted in proportional counters from radiation intensity variations. (author)

  18. Counter-Leadership Targeting and Conflict Termination

    National Research Council Canada - National Science Library

    Taylor, Bradly

    1999-01-01

    .... Can the leader be found? And, is it legal and ethical to attack the leader? Analysis rarely has been conducted to determine whether the targeted organization is vulnerable to Counter Leadership Targeting (CLT...

  19. Countering North Korean Special Purpose Forces

    National Research Council Canada - National Science Library

    Krause, Troy

    1999-01-01

    As United States and Republic of Korea forces stand to defend against a DPRK attack, one of the most formidable tasks is how to counter a second front in the Joint Rear Security Area of the Republic of Korea...

  20. Tests of BF3 counters with getter

    International Nuclear Information System (INIS)

    Comte, R.; Dauphin, G.

    1968-01-01

    BF 3 counters with addition of a getter have been developed to improve operation characteristics of these detectors in presence of strong gamma flows. The getter is made of an active coal deposit on the cathode. As noticed by other studies, the degradation of these counters is related to the exposure to strong neutron flows and to gamma radiations. The authors report tests performed on these counters with a brief presentation of the counters, and a presentation of the test installation. A threshold curve and an amplitude spectrum are obtained, and counting is performed for a fixed threshold before and after the exposure of detectors to variable doses of γ radiation. The results after a first 2 hour long irradiation, a 230 hour long second irradiation, and a third irradiation under high voltage (2100 V) are discussed. Thermal tests are then performed and commented

  1. Real-time {sup 90}Sr Counter

    Energy Technology Data Exchange (ETDEWEB)

    Kaneko, Naomi; Kawai, Hideyuki; Kodama, Satoshi; Kobayashi, Atsushi; Tabata, Makoto; Ito, Hiroshi [Graduate School of Science, Chiba University, Chiba, (Japan); Han, Soorim [Graduate School of Science, Chiba University, Chiba, (Japan); National Institute of Radiological Science, Chiba, (Japan)

    2015-07-01

    Radioisotopes have been emitted around Japan due to a nuclear accident at the Fukushima Daiichi nuclear power station in March 2011. A problem is the contaminated water including the atomic nucleus which relatively has a long half- life time and soluble such as {sup 90}Sr, {sup 137}Cs. Internal exposures by {sup 90}Sr are more dangerous than {sup 137}Cs's because Sr has effective half-life time of 18 years and property of accumulation in a born. We have developed real-time {sup 90}Sr counter which is sensitive beta-ray of maximum kinematic energy of 2.28 MeV from {sup 90}Sr and insensitive of beta-ray of maximum kinematic energy of 1.17 MeV and gamma-ray from {sup 90}Sr by Cherenkov detection. This counter composes of Cerenkov counter, trigger scintillation counter and veto counter. Silica aerogel for Cherenkov counter can obtain refractive index between 1.017 and 1.049 easily. And wavelength shifting fiber (WLSF) is used as a light guide for extending effective area and producing lower cost. A mechanism of the identification of {sup 90}Sr is explained in following. In case of {sup 90}Sr, when the trigger counter reacts on the beta-ray from {sup 90}Sr, aerogel emits the Cherenkov light and WLSF reacts and read the Cherenkov light. On the other hand, in case of {sup 137}Cs, the trigger counter reacts on the beta-ray, aerogel stops the beta- ray and Cherenkov light is not emitted. Therefore, aerogel has a function as a radiator and shielding material. the gamma-ray is not reacted on the lower density detector. Cosmic rays would be also reacted by the veto counter. A prototype counter whose the effective area is 30 cm x 10 cm was obtained (2.0±1.2){sup 3} of mis-identification as {sup 137}Cs/{sup 90}Sr. Detection limit in the surface contamination inspection depends on measurement time and effective area mainly. The sensitivity of wide range, 10{sup -2} - 10{sup 4} Bq/cm{sup 2}, is obtained by adjustment of detection level in circuit of this counter. A lower

  2. Counter - Drug: Mandate for the Army.

    Science.gov (United States)

    1991-03-01

    this comprehensive review will provide a basis for responding to new missions assigned...observations for determining the short-, mid-, and long-term direction of Army support to the national counter-drug effort. Also, this comprehensive review will provide...and long-term direction of Army support to the national counter-drug effort. Also, this comprehensive review will provide a basis for responding

  3. Lifetime characteristics of Gaiger-Muller counters

    Directory of Open Access Journals (Sweden)

    Kartalović Nenad M.

    2016-01-01

    Full Text Available This paper discusses the process of functional aging of Geiger-Muller counters. Two types of Geiger-Muller counter chambers were characterized in an experiment using a combined constant voltage. Chamber A had a coaxial geometry and chamber B had a plan-parallel geometry. The experimental results indicate that the aging process was faster in the case of chambers with a coaxial geometry. The results are explained based on the process of electrical discharges in gasses.

  4. Quality control and the multicrystal counter

    International Nuclear Information System (INIS)

    Hart, G.C.; Davis, K.M.

    1983-01-01

    The reliability of multicrystal counters for use in counting large numbers of radioimmunoassay samples is studied. In particular, the dependencies of the outputs from the array of detectors, and hence their degree of matching, on the count rate and volume of the samples being counted are investigated. Quality control procedures are described to assist in the assurance of consistent performance of the counter in the clinical situation. (U.K.)

  5. Pulse formation of gas-filled counter

    International Nuclear Information System (INIS)

    Iwatani, Kazuo; Teshima, Kazunori; Shizuma, Kiyoshi; Hasai, Hiromi

    1991-01-01

    The pulse formation of gas-filled counter has been calculated by simple models for the proportional and self-quenching streamer (SQS) modes. Calculated pulse shapes of counter output have accurately reproduced the observed ones for both modes. As a result, it is shown that the special density distribution of ion pairs in a streamer can be estimated with the rising part of observed pulse shape, using the model. (author)

  6. Development of a Mobile Ice Nucleus Counter

    Energy Technology Data Exchange (ETDEWEB)

    Kok, Gregory [Droplet Measurement Technologies, Boulder, CO (United States); Kulkarni, Gourihar [Droplet Measurement Technologies, Boulder, CO (United States)

    2014-07-10

    An ice nucleus counter has been constructed. The instrument uses built-in refrigeration systems for wall cooling. A cascade refrigeration system will allow the cold wall to operate as low as -70°C, and a single stage system can operate the warm wall at -45C. A unique optical particle counter has been constructed using polarization detection of the scattered light. This allows differentiation of the particles exiting the chamber to determine if they are ice or liquid.

  7. Single photon detection in the SQS mode

    International Nuclear Information System (INIS)

    Alves, M.A.; Fraga, M.M.; Lima, E.P. de; Marques, R.F.; Neves, F.; Policarpo, A.

    1997-01-01

    Results are presented concerning the detection of single UV photons in self quenching streamer detectors by photoionization of one of the gas mixture components, in this case TEA (tri ethyl-amine), whose molecules have low photoionization potential and large absorption cross section. As a UV light source, a gas scintillation counter filled with krypton was used, whose emission light spectrum, centered at approximately 150 nm, overlaps well the photoionization spectrum of TEA. The mixtures studied were argon/ethane/TEA, argon/isobutane/TEA, argon/ethane/methylal/TEA and argon/isobutane/methylal/ TEA. (author). 4 refs., 4 figs

  8. Photon-photon collisions and photon structure functions at LEP

    CERN Document Server

    Patt, J

    2000-01-01

    The present knowledge of the structure of the photon based on measurements of photon structure functions is discussed. This review covers recent results on QED structure functions and on the hadronic structure function F/sub 2//sup gamma /. (13 refs).

  9. Excitation of accelerating plasma waves by counter-propagating laser beams

    International Nuclear Information System (INIS)

    Shvets, Gennady; Fisch, Nathaniel J.; Pukhov, Alexander

    2002-01-01

    The conventional approach to exciting high phase velocity waves in plasmas is to employ a laser pulse moving in the direction of the desired particle acceleration. Photon downshifting then causes momentum transfer to the plasma and wave excitation. Novel approaches to plasma wake excitation, colliding-beam accelerator (CBA), which involve photon exchange between the long and short counter-propagating laser beams, are described. Depending on the frequency detuning Δω between beams and duration τ L of the short pulse, there are two approaches to CBA. First approach assumes (τ L ≅2/ω p ). Photons exchanged between the beams deposit their recoil momentum in the plasma driving the plasma wake. Frequency detuning between the beams determines the direction of the photon exchange, thereby controlling the phase of the plasma wake. This phase control can be used for reversing the slippage of the accelerated particles with respect to the wake. A variation on the same theme, super-beatwave accelerator, is also described. In the second approach, a short pulse with τ L >>ω p -1 detuned by Δω∼2ω p from the counter-propagating beam is employed. While parametric excitation of plasma waves by the electromagnetic beatwave at 2ω p of two co-propagating lasers was first predicted by Rosenbluth and Liu [M. N. Rosenbluth and C. S. Liu, Phys. Rev. Lett. 29, 701 (1972)], it is demonstrated that the two excitation beams can be counter-propagating. The advantages of using this geometry (higher instability growth rate, insensitivity to plasma inhomogeneity) are explained, and supporting numerical simulations presented

  10. Photonic Crystals Towards Nanoscale Photonic Devices

    CERN Document Server

    Lourtioz, Jean-Michel; Berger, Vincent; Gérard, Jean-Michel; Maystre, Daniel; Tchelnokov, Alexei; Pagnoux, Dominique

    2008-01-01

    Just like the periodical crystalline potential in solid state crystals determines their properties for the conduction of electrons, the periodical structuring of photonic crystals leads to envisioning the possibility of achieving a control of the photon flux in dielectric and metallic materials. The use of photonic crystals as cages for storing, filtering or guiding light at the wavelength scale paves the way to the realization of optical and optoelectronic devices with ultimate properties and dimensions. This will contribute towards meeting the demands for greater miniaturization imposed by the processing of an ever increasing number of data. Photonic Crystals will provide students and researchers from different fields with the theoretical background required for modelling photonic crystals and their optical properties, while at the same time presenting the large variety of devices, ranging from optics to microwaves, where photonic crystals have found application. As such, it aims at building bridges between...

  11. Photonic Crystals Towards Nanoscale Photonic Devices

    CERN Document Server

    Lourtioz, Jean-Michel; Berger, Vincent; Gérard, Jean-Michel; Maystre, Daniel; Tchelnokov, Alexis

    2005-01-01

    Just like the periodical crystalline potential in solid-state crystals determines their properties for the conduction of electrons, the periodical structuring of photonic crystals leads to envisioning the possibility of achieving a control of the photon flux in dielectric and metallic materials. The use of photonic crystals as a cage for storing, filtering or guiding light at the wavelength scale thus paves the way to the realisation of optical and optoelectronic devices with ultimate properties and dimensions. This should contribute toward meeting the demands for a greater miniaturisation that the processing of an ever increasing number of data requires. Photonic Crystals intends at providing students and researchers from different fields with the theoretical background needed for modelling photonic crystals and their optical properties, while at the same time presenting the large variety of devices, from optics to microwaves, where photonic crystals have found applications. As such, it aims at building brid...

  12. Photon and photon reactions: elementary theoretical introduction

    International Nuclear Information System (INIS)

    Diu, B.

    The electromagnetic field and associated quanta, the photons, are simply and briefly studied. The conventional electromagnetism laws are recalled. Fundamental concepts such as gauge invariance, the electromagnetic current conservation, and photon behavior against the internal symmetries of strong interactions are simply introduced. Results and notations are applied to analysis of reactions where photons intervene in initial or final states (photoproduction) within the limits of amplitude properties in the conventional space-time. The helicity and invariant amplitude formalisms are compared [fr

  13. Upper limit for the emission of monoenergetic photons in Y(1S)- and Y(2S)-meson decays

    International Nuclear Information System (INIS)

    Albrecht, H.; Binder, U.; Harder, G.; Lembke-Koppitz, I.; Philipp, A.; Schmidt-Parzefall, W.; Schroeder, H.; Schulz, H.D.; Wurth, R.; Drescher, H.; Graewe, B.; Matthiesen, U.; Scheck, H.; Spengler, J.; Wegener, D.; Edwards, K.W.; Kapitza, H.; Yun, J.C.; Frisken, W.R.; Fukunaga, C.; Goddard, M.; Gilkinson, D.J.; Gingrich, D.M.; Kim, P.C.H.; Kutschke, R.; MacFarlane, D.B.; McKenna, J.A.; Orr, R.S.; Padley, P.; Prentice, J.D.; Seywerd, H.C.J.; Stacey, B.J.; Yoon, T.S.; Ammar, R.; Coppage, D.; Davis, R.; Kanekal, S.; Kwak, N.; Kernel, G.; Plesko, M.; Childers, R.; Darden, C.W.; Gennow, H.

    1985-08-01

    We report the results of a search for monoenergetic photons in the decay of both the Y(1S)- and the Y(2S)-meson. Photons converted in the beam tube or the drift chamber inner wall, and photons detected with the barrel shower counters of the ARGUS detector, respectively, have been used in the analysis. No narrow peak is observed in the energy interval 0.5 GeV<=Esub(γ)<=4.0 GeV. (orig.)

  14. Photon-Counting Arrays for Time-Resolved Imaging

    Directory of Open Access Journals (Sweden)

    I. Michel Antolovic

    2016-06-01

    Full Text Available The paper presents a camera comprising 512 × 128 pixels capable of single-photon detection and gating with a maximum frame rate of 156 kfps. The photon capture is performed through a gated single-photon avalanche diode that generates a digital pulse upon photon detection and through a digital one-bit counter. Gray levels are obtained through multiple counting and accumulation, while time-resolved imaging is achieved through a 4-ns gating window controlled with subnanosecond accuracy by a field-programmable gate array. The sensor, which is equipped with microlenses to enhance its effective fill factor, was electro-optically characterized in terms of sensitivity and uniformity. Several examples of capture of fast events are shown to demonstrate the suitability of the approach.

  15. Active Photonic Crystal Waveguides

    DEFF Research Database (Denmark)

    Ek, Sara

    This thesis deals with the fabrication and characterization of active photonic crystal waveguides, realized in III-V semiconductor material with embedded active layers. The platform offering active photonic crystal waveguides has many potential applications. One of these is a compact photonic...... due to photonic crystal dispersion. The observations are explained by the enhancement of net gain by light slow down. Another application based on active photonic crystal waveguides is micro lasers. Measurements on quantum dot micro laser cavities with different mirror configurations and photonic...

  16. THGEM based photon detector for Cherenkov imaging applications

    CERN Document Server

    Alexeev, M; Bradamante, F; Bressan, A; Chiosso, M; Ciliberti, P; Croci, G; Colantoni, M L; Dalla Torre, S; Duarte Pinto, S; Denisov, O; Diaz, V; Ferrero, A; Finger, M; Finger, M Jr; Fischer, H; Giacomini, G; Giorgi, M; Gobbo, B; Heinsius, F H; Herrmann, F; Jahodova, V; Königsmann, K; Lauser, L; Levorato, S; Maggiora, A; Martin, A; Menon, G; Nerling, F; Panzieri, D; Pesaro, G; Polak, J; Rocco, E; Ropelewski, L; Sauli, F; Sbrizzai, G; Schiavon, P; Schill, C; Schopferer, S; Slunecka, M; Sozzi, F; Steiger, L; Sulc, M; Takekawa, S; Tessarotto, F; Wollny, H

    2010-01-01

    We are developing a single photon detector for Cherenkov imaging counters. This detector is based on the use of THGEM electron multipliers in a multilayer design. The major goals of our project are ion feedback suppression down to a few per cent, large gain, fast response, insensitivity to magnetic fields, and a large detector size. We report about the project status and perspectives. In particular, we present a systematic study of the THGEM response as a function of geometrical parameters, production techniques and the gas mixture composition. The first figures obtained from measuring the response of a CsI coated THGEM to single photons are presented.

  17. Photonic crystals: towards nanoscale photonic devices

    National Research Council Canada - National Science Library

    Lourtioz, J.-M

    2005-01-01

    .... From this point of view, the emergence of photonic bandgap materials and photonic crystals at the end of the 1980s can be seen as a revenge to the benefit this time of optics and electromagnetism. In the same way as the periodicity of solid state crystals determines the energy bands and the conduction properties of electrons, the periodical structur...

  18. Quantum Biometrics with Retinal Photon Counting

    Science.gov (United States)

    Loulakis, M.; Blatsios, G.; Vrettou, C. S.; Kominis, I. K.

    2017-10-01

    It is known that the eye's scotopic photodetectors, rhodopsin molecules, and their associated phototransduction mechanism leading to light perception, are efficient single-photon counters. We here use the photon-counting principles of human rod vision to propose a secure quantum biometric identification based on the quantum-statistical properties of retinal photon detection. The photon path along the human eye until its detection by rod cells is modeled as a filter having a specific transmission coefficient. Precisely determining its value from the photodetection statistics registered by the conscious observer is a quantum parameter estimation problem that leads to a quantum secure identification method. The probabilities for false-positive and false-negative identification of this biometric technique can readily approach 10-10 and 10-4, respectively. The security of the biometric method can be further quantified by the physics of quantum measurements. An impostor must be able to perform quantum thermometry and quantum magnetometry with energy resolution better than 10-9ℏ , in order to foil the device by noninvasively monitoring the biometric activity of a user.

  19. Jet and hadron production in photon-photon collisions

    OpenAIRE

    Soldner-Rembold, Stefan

    1999-01-01

    Di-jet and inclusive charged hadron production cross-sections measured in photon-photon collisions by OPAL are compared to NLO pQCD calculations. Jet shapes measured in photon-photon scattering by OPAL, in deep-inelastic ep scattering by H1 and in photon-proton scattering by ZEUS are shown to be consistent in similar kinematic ranges. New results from TOPAZ on prompt photon production in photon-photon interactions are presented.

  20. Photonic crystal pioneer

    Science.gov (United States)

    Anscombe, Nadya

    2011-08-01

    Over the past ten years, Crystal Fiber, now part of NKT Photonics, has been busy commercializing photonic crystal fibre. Nadya Anscombe finds out about the evolution of the technology and its applications.

  1. Photonic Design for Photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Kosten, E.; Callahan, D.; Horowitz, K.; Pala, R.; Atwater, H.

    2014-08-28

    We describe photonic design approaches for silicon photovoltaics including i) trapezoidal broadband light trapping structures ii) broadband light trapping with photonic crystal superlattices iii) III-V/Si nanowire arrays designed for broadband light trapping.

  2. Photonic crystal light source

    Science.gov (United States)

    Fleming, James G [Albuquerque, NM; Lin, Shawn-Yu [Albuquerque, NM; Bur, James A [Corrales, NM

    2004-07-27

    A light source is provided by a photonic crystal having an enhanced photonic density-of-states over a band of frequencies and wherein at least one of the dielectric materials of the photonic crystal has a complex dielectric constant, thereby producing enhanced light emission at the band of frequencies when the photonic crystal is heated. The dielectric material can be a metal, such as tungsten. The spectral properties of the light source can be easily tuned by modification of the photonic crystal structure and materials. The photonic crystal light source can be heated electrically or other heating means. The light source can further include additional photonic crystals that exhibit enhanced light emission at a different band of frequencies to provide for color mixing. The photonic crystal light source may have applications in optical telecommunications, information displays, energy conversion, sensors, and other optical applications.

  3. Photon structure function - theory

    International Nuclear Information System (INIS)

    Bardeen, W.A.

    1984-12-01

    The theoretical status of the photon structure function is reviewed. Particular attention is paid to the hadronic mixing problem and the ability of perturbative QCD to make definitive predictions for the photon structure function. 11 references

  4. Photon wave function

    OpenAIRE

    Bialynicki-Birula, Iwo

    2005-01-01

    Photon wave function is a controversial concept. Controversies stem from the fact that photon wave functions can not have all the properties of the Schroedinger wave functions of nonrelativistic wave mechanics. Insistence on those properties that, owing to peculiarities of photon dynamics, cannot be rendered, led some physicists to the extreme opinion that the photon wave function does not exist. I reject such a fundamentalist point of view in favor of a more pragmatic approach. In my view, t...

  5. Functionalized 2PP structures for the BioPhotonics Workstation

    DEFF Research Database (Denmark)

    Matsuoka, Tomoyo; Nishi, Masayuki; Sakakura, Masaaki

    2011-01-01

    In its standard version, our BioPhotonics Workstation (BWS) can generate multiple controllable counter-propagating beams to create real-time user-programmable optical traps for stable three-dimensional control and manipulation of a plurality of particles. The combination of the platform with micr...... on the BWS platform by functionalizing them with silica-based sol-gel materials inside which dyes can be entrapped....

  6. Quantum state propagation in linear photonic bandgap structures

    International Nuclear Information System (INIS)

    Severini, S; Tricca, D; Sibilia, C; Bertolotti, M; Perina, Jan

    2004-01-01

    In this paper we investigate the propagation of a generic quantum state in a corrugated waveguide, which reproduces a photonic bandgap structure. We find the conditions that assure the outcoming state to preserve the quantum properties of the incoming state. Then, focusing on a particular quantum state (realized by two counter-propagating coherent states), we study the possibility of preserving the quantum properties of this particular double coherent state even in the presence of absorption phenomena during propagation in the structure

  7. Calibration of the whole body counter at PSI

    International Nuclear Information System (INIS)

    Mayer, Sabine; Boschung, Markus; Fiechtner, Annette; Habegger, Ruedi; Meier, Kilian; Wernli, Christian

    2008-01-01

    At the Paul Scherrer Institut (PSI), measurements with the whole body counter are routinely carried out for occupationally exposed persons and occasionally for individuals of the population suspected of radioactive intake. In total about 400 measurements are performed per year. The whole body counter is based on a p-type high purity germanium (HPGe) coaxial detector mounted above a canvas chair in a shielded small room. The detector is used to detect the presence of radionuclides that emit photons with energies between 50 keV and 2 MeV. The room itself is made of iron from old railway rails to reduce the natural background radiation to 24 n Sv/h. The present paper describes the calibration of the system with the IGOR phantom. Different body sizes are realized by different standardized configurations of polyethylene bricks, in which small tubes of calibration sources can be introduced. The efficiency of the detector was determined for four phantom geometries (P1, P2, P4 and P6 simulating human bodies in sitting position of 12 kg, 24 kg, 70 kg and 110 kg, respectively. The measurements were performed serially using five different radionuclide sources ( 40 K, 60 Co, 133 Ba, 137 Cs, 152 Eu) within the phantom bricks. Based on results of the experiment, an efficiency curve for each configuration and the detection limits for relevant radionuclides were determined. For routine measurements, the efficiency curve obtained with the phantom geometry P4 was chosen. The detection limits range from 40 Bq to 1000 Bq for selected radionuclides applying a measurement time of 7 min. The proper calibration of the system, on one hand, is essential for the routine measurements at PSI. On the other hand, it serves as a benchmark for the already initiated characterisation of the system with Monte Carlo simulations. (author)

  8. A CZT-based blood counter for quantitative molecular imaging.

    Science.gov (United States)

    Espagnet, Romain; Frezza, Andrea; Martin, Jean-Pierre; Hamel, Louis-André; Lechippey, Laëtitia; Beauregard, Jean-Mathieu; Després, Philippe

    2017-12-01

    Robust quantitative analysis in positron emission tomography (PET) and in single-photon emission computed tomography (SPECT) typically requires the time-activity curve as an input function for the pharmacokinetic modeling of tracer uptake. For this purpose, a new automated tool for the determination of blood activity as a function of time is presented. The device, compact enough to be used on the patient bed, relies on a peristaltic pump for continuous blood withdrawal at user-defined rates. Gamma detection is based on a 20 × 20 × 15 mm 3 cadmium zinc telluride (CZT) detector, read by custom-made electronics and a field-programmable gate array-based signal processing unit. A graphical user interface (GUI) allows users to select parameters and easily perform acquisitions. This paper presents the overall design of the device as well as the results related to the detector performance in terms of stability, sensitivity and energy resolution. Results from a patient study are also reported. The device achieved a sensitivity of 7.1 cps/(kBq/mL) and a minimum detectable activity of 2.5 kBq/ml for 18 F. The gamma counter also demonstrated an excellent stability with a deviation in count rates inferior to 0.05% over 6 h. An energy resolution of 8% was achieved at 662 keV. The patient study was conclusive and demonstrated that the compact gamma blood counter developed has the sensitivity and the stability required to conduct quantitative molecular imaging studies in PET and SPECT.

  9. Diffusion Based Photon Mapping

    DEFF Research Database (Denmark)

    Schjøth, Lars; Fogh Olsen, Ole; Sporring, Jon

    2007-01-01

    . To address this problem we introduce a novel photon mapping algorithm based on nonlinear anisotropic diffusion. Our algorithm adapts according to the structure of the photon map such that smoothing occurs along edges and structures and not across. In this way we preserve the important illumination features......, while eliminating noise. We call our method diffusion based photon mapping....

  10. Diffusion Based Photon Mapping

    DEFF Research Database (Denmark)

    Schjøth, Lars; Olsen, Ole Fogh; Sporring, Jon

    2006-01-01

    . To address this problem we introduce a novel photon mapping algorithm based on nonlinear anisotropic diffusion. Our algorithm adapts according to the structure of the photon map such that smoothing occurs along edges and structures and not across. In this way we preserve the important illumination features......, while eliminating noise. We call our method diffusion based photon mapping....

  11. Photonic crystal fibers

    DEFF Research Database (Denmark)

    Lægsgaard, Jesper; Hansen, K P; Nielsen, M D

    2003-01-01

    Photonic crystal fibers having a complex microstructure in the transverse plane constitute a new and promising class of optical fibers. Such fibers can either guide light through total internal reflection or the photonic bandgap effect, In this paper, we review the different types and applications...... of photonic crystal fibers with particular emphasis on recent advances in the field....

  12. The Banking Counter-Guarantee. Juridical Regime

    Directory of Open Access Journals (Sweden)

    Postolache Rada

    2009-06-01

    Full Text Available Not so much studied by the specialised literature, the banking counter-guarantee may beconfounded with the other types of guarantee which frequently go with the guaranteed obligation –simple guarantee, collateral guarantee, the confirmation of the guarantee. The counter-guarantee may bean independent or accessory obligation, as the case may be, exclusively governed by its text, accordingto the parties’ will. At the same time, it is a complex juridical act, a contract whose contents cannot beset apart from the contracts connected form an “economic” point of view. The counter-guarantee is theresult of the banking practice and is generated by the need to make amends for the flaws generated bythe direct guarantee. The present research is focused on the analysis of the banking practice, normativeacts, jurisprudence and banking juridical literature.

  13. CORNELL: CLEO's counters

    International Nuclear Information System (INIS)

    Anon.

    1982-01-01

    Particle identification by measuring ionization is complicated by the fact that the energy lost to ionization in passing through matter has large fluctuations, first calculated by Landau. These large fluctuations imply that many measurements must be made in order to determine the most probable ionization value that is characteristic of the particle type. The JADE chamber at PETRA and the TPC chamber at PEP measure both the ionization and the momenta of tracks in the same device. In the CLEO experiment at Cornell's CESR ring, ionization is measured in dedicated energy loss counters contained in each of the eight octants surrounding the drift chamber and superconducting coil. The last of these were installed in the summer of 1981, replacing Cherenkov counters that were used while the energy loss counters were being developed and built

  14. An extended range neutron rem counter

    International Nuclear Information System (INIS)

    Birattari, C.; Nuccetelli, C.; Pelliccioni, M.; Silari, M.

    1990-01-01

    Extensive Monte Carlo calculations have been carried out to assess the possibility of extending the sensitivity of a neutron rem counter of the Andersson-Braun type up to several hundred MeV. The validity of the model adopted has first been checked by comparing with experimental data the calculated response curve and the angular dependence of the sensitivity for a well known commercial rem counter. Next, a number of modifications to the configuration of the moderator-attenuator have been investigated. The response functions and angular distributions produced by two simple solutions yielding an instrument with a sensitivity extended up to 400 MeV are presented. The response of the original rem counter and of its two modified versions to nine test spectra has also been calculated. The resulting instrument is transportable rather than portable, but the availability of an extended range neutron survey meter would be of great advantage at medium and high energy particle accelerator facilities. (orig.)

  15. Count rate effect in proportional counters

    International Nuclear Information System (INIS)

    Bednarek, B.

    1980-01-01

    A new concept is presented explaining changes in spectrometric parameters of proportional counters which occur due to varying count rate. The basic feature of this concept is that the gas gain of the counter remains constant in a wide range of count rate and that the decrease in the pulse amplitude and the detorioration of the energy resolution observed are the results of changes in the shape of original current pulses generated in the active volume of the counter. In order to confirm the validity of this statement, measurements of the gas amplification factor have been made in a wide count rate range. It is shown that above a certain critical value the gas gain depends on both the operating voltage and the count rate. (author)

  16. Calibration of nuclear medicine gamma counters

    International Nuclear Information System (INIS)

    Orlic, M.; Spasic-Jokic, V.; Jovanovic, M.; Vranjes, S. . E-mail address of corresponding author: morlic@vin.bg.ac.yu; Orlic, M.)

    2005-01-01

    In this paper the practical problem of nuclear medicine gamma counters calibration has been solved by using dose calibrators CRC-15R with standard error ±5%. The samples from technetium generators have been measured both by dose calibrators CRC-15R and gamma counter ICN Gamma 3.33 taking into account decay correction. Only the linear part of the curve has practical meaning. The advantage of this procedure satisfies the requirements from international standards: the calibration of sources used for medical exposure be traceable to a standard dosimetry laboratory and radiopharmaceuticals for nuclear medicine procedures be calibrated in terms of activity of the radiopharmaceutical to be administered. (author)

  17. Analysis of counter-rotating wind turbines

    DEFF Research Database (Denmark)

    Shen, Wen Zhong; Zakkam, Vinod Arun Kumar; Sørensen, Jens Nørkær

    2007-01-01

    This paper presents a study on the performance of a wind turbine with two counter-rotating (CRWT) rotors. The characteristics of the two counter-rotating rotors are on a 3-bladed Nordtank 500 kW rotor. The analysis has been carried out by using an Actuator Line technique implemented in the Navier......-Stokes code EllipSys3D. The analysis shows that the Annual Energy Production can be increased to about 43.5 %, as compared to a wind turbine with a single rotor. In order to determine the optimal settings of the CRWT turbine, parameters such as distance between two rotors and rotational speed have been...

  18. Development of DUPIC safeguards neutron counter

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Young Gil; Cha, Hong Ryul; Kim, Ho Dong; Hong, Jong Sook; Kang, Hee Young

    1999-08-01

    KAERI, in cooperation with LANL, developed DSNC (DUPIC Safeguards Neutron Counter) for safeguards implementing on DUPIC process which is under development by KAERI for direct use of spent PWR fuel in CANDU reactors. DSNC is a well-type neutron coincidence counter with substantial shielding to protect system from high gamma radiation of spent fuel. General development procedures in terms of design, manufacturing, fabrication, cold and hot test, performance test for DSNC authentication by KAERI-IAEA-LANL are described in this report. It is expected that the techniques related DSNC development and associated neutron detection and evaluation method could be applied for safeguards improvement. (Author). 20 refs., 16 tabs. 98 figs.

  19. Counter of radiation in body parts

    International Nuclear Information System (INIS)

    Pollard, D.E.

    1983-01-01

    A new radiation counter for the determination of radiocontaminated body parts has been designed. Composed of several movable detectors, shielded from background radiation and focused on different parts of the human body by narrow apertures in the lead enclosure, the invention provides a quick tool for quantitative and qualitative part-by-part analysis of the body with respect to radiocontamination. The counter can be handled easily by the tested person himself and consequently, it is suitable for mass controls etc. (G.J.P.)

  20. Whole body counters: types, performance and uses

    International Nuclear Information System (INIS)

    Jales, R.L.C.

    1983-01-01

    The present monograph deals with Whole Counters, since its definition, evolution, performance, clinical indications and results. Scintillation crystals detection systems were described as well as scintillant solutions, plastic scintillations, and gaseous detectors, including its interplay forms and basal characteristics. Geometric arrangements of standard chair, arc and hammock, arrangements with scintillant solutions and plastic scintillations, as well as special geometric arrangements were equally commented. Clinic and experimental studies were also dealt with Whole Body Counters, giving examples with potassium, iron vitamin B 12 and albumin. (author)

  1. Silicon Microspheres Photonics

    International Nuclear Information System (INIS)

    Serpenguzel, A.

    2008-01-01

    Electrophotonic integrated circuits (EPICs), or alternatively, optoelectronic integrated circuit (OEICs) are the natural evolution of the microelectronic integrated circuit (IC) with the addition of photonic capabilities. Traditionally, the IC industry has been based on group IV silicon, whereas the photonics industry on group III-V semiconductors. However, silicon based photonic microdevices have been making strands in siliconizing photonics. Silicon microspheres with their high quality factor whispering gallery modes (WGMs), are ideal candidates for wavelength division multiplexing (WDM) applications in the standard near-infrared communication bands. In this work, we will discuss the possibility of using silicon microspheres for photonics applications in the near-infrared

  2. Photon correlation holography.

    Science.gov (United States)

    Naik, Dinesh N; Singh, Rakesh Kumar; Ezawa, Takahiro; Miyamoto, Yoko; Takeda, Mitsuo

    2011-01-17

    Unconventional holography called photon correlation holography is proposed and experimentally demonstrated. Using photon correlation, i.e. intensity correlation or fourth order correlation of optical field, a 3-D image of the object recorded in a hologram is reconstructed stochastically with illumination through a random phase screen. Two different schemes for realizing photon correlation holography are examined by numerical simulations, and the experiment was performed for one of the reconstruction schemes suitable for the experimental proof of the principle. The technique of photon correlation holography provides a new insight into how the information is embedded in the spatial as well as temporal correlation of photons in the stochastic pseudo thermal light.

  3. Cross-talk of a multi-anode PMT and attainment of a σ∼10ps TOF counter

    International Nuclear Information System (INIS)

    Enari, Y.; Hayasaka, K.; Hokuue, T.; Inami, K.; Ohshima, T.; Sato, N.; Akatsu, M.; Kawakami, S.; Miyabayashi, Y.; Tokuda, H.; Yanase, H.; Shimoi, H.; Fujimori, T.

    2005-01-01

    We extensively studied a cross-talk phenomenon that seriously deteriorates the high time-resolution of a multi-anode 16-channel linear array photo-multiplier tube (PMT); the dynode structures were modified to eliminate the cross-talk effect and to recover a time resolution of σ=70-80ps for single photons. The use of 16 anode signals of the modified PMT enabled us to attain σ=12ps for a small TOF counter of Cherenkov radiation

  4. Electron and Photon ID

    CERN Document Server

    Hryn'ova, Tetiana; The ATLAS collaboration

    2017-01-01

    The identification of prompt photons and the rejection of background coming mostly from photons from hadron decays relies on the high granularity of the ATLAS calorimeter. The electron identification used in ATLAS for run 2 is based on a likelihood discrimination to separate isolated electron candidates from candidates originating from photon conversions, hadron misidentification and heavy flavor decays. In addition, isolation variables are used as further handles to separate signal and background. Several methods are used to measure with data the efficiency of the photon identification requirements, to cover a broad energy spectrum. At low energy, photons from radiative Z decays are used. In the medium energy range, similarities between electrons and photon showers are exploited using Z->ee decays. At high energy, inclusive photon samples are used. The measurement of the efficiencies of the electron identification and isolation cuts are performed with the data using tag and probe techniques with large statis...

  5. Inclusive hard processes in photon-photon and photon-proton interactions

    OpenAIRE

    Glasman, Claudia

    1999-01-01

    Measurements of jet, prompt photon, high-pT hadron and heavy quark production in photon-induced processes provide tests of QCD and are sensitive to the photon parton densities. A review of the latest experimental results in photon-photon and photon-proton interactions is presented. Next-to-leading-order QCD calculations for these measurements are discussed.

  6. Semi-portable whole body counter deployable during post-radiological accident

    International Nuclear Information System (INIS)

    Panchal, C.G.; Bansode, P.Y.; Vinod, M.; Sarade, Bhagyashree; Jain, R.K.; Jakati, R.K.; Pithawa, C.K.

    2012-01-01

    A versatile whole body counter with the state of art electronics has been indigenously designed and developed which can be readily deployed for use during nuclear emergency. This instrument is designed to quickly identify and quantify the activity of high energy photon emitters accumulated particularly in vital organs like thyroid, lungs besides the body of the victims of the radiological incident or accident. Special features of the instruments are swivel type detectors assembly mountable on a wall or table top and detachable collimator configurable to assess the internal contamination selectively to meet protective measures of the radiological accidents, mechanically rugged and functionally reliable to perform in contaminated environmental field conditions. (author)

  7. 'Miniskirt' counter array at CDF II

    International Nuclear Information System (INIS)

    Artikov, A.; Artikov, A.

    2006-01-01

    Full text: Muon detection is fundamental for the most of the interesting analyses at CDF. At the course of Run II, the collaboration expects to collect hundreds of t t-bar decays yielding a muon as well as several million B-hadron events involving J/ψ → μ + μ - decays. Muon detection is also of fundamental importance in the study of W-boson properties and in the search for Higgs production associated with W or Z bosons. Considerable effort therefore went into extending the muon detector coverage for Run II, which started in March 2001. The CDF II muon detector system consists of multiple layers of drift chambers and scintillation counters, which span the pseudorapidity (|η|) range between 0 and 1.5. Detectors spanning different ranges have different geometries, and the muon scintillation counter system includes subsystems in the regions that have come to be known as the 'central' (0 pe for WLS fiber readout is smaller than for conventional readout, we can also expect an increase in the statistical contribution to the overall uncertainty. Our first concern, before adopting this solution, was therefore to ascertain that the mean timing resolution obtained under these conditions was adequate. The modifications, testing and installation of these counters within the CDF Upgrade Project are described in detail. The timing characteristics of MSX' counters are also investigated using cosmic muons. The measurements show that the time resolution does not exceed 2.2 ns. (author)

  8. Cerenkov counters at the Omega Facility

    CERN Multimedia

    1975-01-01

    P. Petroff on the left. Here one sees both the gas Cerenkov counters sitting in front of the magnet to select forward emitted particles. The smaller one, working at high pressure, sits nearest to the Omega magnet (see photo 7505073X), the other (see photo 7505071X) works at atmospheric pressure.

  9. A gridded air counter for measuring exoelectrons

    International Nuclear Information System (INIS)

    Nagase, Makoto; Chiba, Yoshiya; Kirihata, Humiaki.

    1980-01-01

    A gridded air counter with a quenching circuit is described, which serves to detect low-energy electrons such as thermionic electrons, photoelectrons and exoelectrons emitted into the atmospheric air. The air counter consists of a loop-shaped anode and two grids provided for quenching the gas discharge and for protecting the electron emitter from the positive ion bombardment. The quenching circuit with a high input sensitivity of 5 mV detects the initiation gas discharge caused by an incident electron and immediately supplies a rectangular wave pulse of 300 V in amplitude and of more than 3 msec in width to the quenching grid near the anode. Simultaneously, the voltage of the suppressor grid is brought down and kept at -30 V against the earthed sample for the same period of time. Performance of the gridded air counter was examined by use of photoelectrons emitted from an abraded aluminum plate. The quenching action was successfully accomplished in the anode voltage range from 3.65 to 3.95 kV. The photoelectrons emitted into the atmosphere could be counted stably by use of this counter. (author)

  10. Platelet counting using the Coulter electronic counter.

    Science.gov (United States)

    Eggleton, M J; Sharp, A A

    1963-03-01

    A method for counting platelets in dilutions of platelet-rich plasm using the Coulter electronic counter is described.(1) The results obtained show that such platelet counts are at least as accurate as the best methods of visual counting. The various technical difficulties encountered are discussed.

  11. Counter Trafficking System Development "Analysis Training Program"

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, Dennis C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2010-12-01

    This document will detail the training curriculum for the Counter-Trafficking System Development (CTSD) Analysis Modules and Lesson Plans are derived from the United States Military, Department of Energy doctrine and Lawrence Livermore National Laboratory (LLNL), Global Security (GS) S Program.

  12. Micropipette as Coulter counter for submicron particles

    Science.gov (United States)

    Rudzevich, Yauheni; Ordonez, Tony; Evans, Grant; Chow, Lee

    2011-03-01

    Coulter counter based on micropipette has been around for several decades. Typical commercial Coulter counter has a pore size of 20 μ m, and is designed to detect micron-size blood cells. In recent years, there are a lot of interests in using nanometer pore size Coulter counter to detect single molecule and to sequence DNA. Here we describe a simple nanoparticle counter based on pulled micropipettes with a diameter of 50 -- 500 nm. Borosilicate micropipettes with an initial outer diameter of 1.00 mm and inner diameter of 0.5 mm are used. After pulling, the micropipettes are fire polished and ultrasound cleaned. Chlorinated Ag/AgCl electrodes and 0.1 M of KCl solution are used. The ionic currents are measured using an Axopatch 200B amplifier in the voltage-clamp mode. Several types and sizes of nanoparticles are measured, including plain silica and polystyrene nanospheres. The results will be discussed in terms of pH values of the solution and concentrations of the nanoparticles. Financial support from National Science Foundation (NSF-0901361) is acknowledged.

  13. Sealed drift tube cosmic ray veto counters

    International Nuclear Information System (INIS)

    Rios, R.; Tatar, E.; Bacon, J.D.; Bowles, T.J.; Hill, R.; Green, J.A.; Hogan, G.E.; Ito, T.M.; Makela, M.; Morris, C.L.; Mortenson, R.; Pasukanics, F.E.; Ramsey, J.; Saunders, A.; Seestrom, S.J.; Sondheim, W.E.; Teasdale, W.; Saltus, M.; Back, H.O.; Cottrell, C.R.

    2011-01-01

    We describe a simple drift tube counter that has been used as a cosmic ray veto for the UCNA experiment, a first-ever measurement of the neutron beta-asymmetry using ultra-cold neutrons. These detectors provide an inexpensive alternative to more conventional scintillation detectors for large area cosmic ray anticoincidence detectors.

  14. COUNTER-ROTATION IN RELATIVISTIC MAGNETOHYDRODYNAMIC JETS

    Energy Technology Data Exchange (ETDEWEB)

    Cayatte, V.; Sauty, C. [Laboratoire Univers et Théories, Observatoire de Paris, UMR 8102 du CNRS, Université Paris Diderot, F-92190 Meudon (France); Vlahakis, N.; Tsinganos, K. [Department of Astrophysics, Astronomy and Mechanics, Faculty of Physics, University of Athens, 15784 Zografos, Athens (Greece); Matsakos, T. [Department of Astronomy and Astrophysics, The University of Chicago, Chicago, IL 60637 (United States); Lima, J. J. G., E-mail: veronique.cayatte@obspm.fr [Centro de Astrofísica, Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal)

    2014-06-10

    Young stellar object observations suggest that some jets rotate in the opposite direction with respect to their disk. In a recent study, Sauty et al. showed that this does not contradict the magnetocentrifugal mechanism that is believed to launch such outflows. Motion signatures that are transverse to the jet axis, in two opposite directions, have recently been measured in M87. One possible interpretation of this motion is that of counter-rotating knots. Here, we extend our previous analytical derivation of counter-rotation to relativistic jets, demonstrating that counter-rotation can indeed take place under rather general conditions. We show that both the magnetic field and a non-negligible enthalpy are necessary at the origin of counter-rotating outflows, and that the effect is associated with a transfer of energy flux from the matter to the electromagnetic field. This can be realized in three cases: if a decreasing enthalpy causes an increase of the Poynting flux, if the flow decelerates, or if strong gradients of the magnetic field are present. An illustration of the involved mechanism is given by an example of a relativistic magnetohydrodynamic jet simulation.

  15. Townsend coefficients of gases in avalanche counters

    International Nuclear Information System (INIS)

    Brunner, G.

    1978-01-01

    Though much work has been done by many authors in the last few years in the development and application of avalanche counters for ion radiation, it is based upon values of the Townsend coefficients as the essential gas parameter, which were determined many years ago for much lower reduced field strengths F/p than prevail in such counters. Therefore absolute determinations of α in vapours of methyl alcohol, cyclohexane, acetone, and n-heptene were performed under original conditions of avalanche counters. The values obtained do not differ by more than 30%-50% from the former values indeed, extrapolated over F/p for the first three mentioned substances, but the amounts of A and B in the usual representation α/p=A exp(-B(F/p)) are much greater for the stronger reduced fields. This is of importance for such counter properties as the dependence of pulse heights on pressure, voltage, electrode distance etc., which are governed by other combinations of A and B than α/p itself. A comparison of results for different ionic radiations shows a marked influence of the primary ionization density along the particle tracks which is hard to explain. (Auth.)

  16. Can counter-stereotypes boost flexible thinking?

    NARCIS (Netherlands)

    Goclowska, M.A.; Crisp, R.J.; Labuschagne, K.

    2013-01-01

    To reduce prejudice psychologists design interventions requiring people to think of counter-stereotypes (i.e., people who defy stereotypic expectations—a strong woman, a Black President). Grounded in the idea that stereotypes constrain the ability to think flexibly, we propose that thinking of

  17. Calibration of proportional counters in microdosimetry

    International Nuclear Information System (INIS)

    Varma, M.N.

    1982-01-01

    Many microdosimetric spectra for low LET as well as high LET radiations are measured using commercially available (similar to EG and G) Rossi proportional counters. This paper discusses the corrections to be applied to data when calibration of the counter is made using one type of radiation, and then the counter is used in a different radiation field. The principal correction factor is due to differences in W-value of the radiation used for calibration and the radiation for which microdosimetric measurements are made. Both propane and methane base tissue-equivalent (TE) gases are used in these counters. When calibrating the detectors, it is important to use the correct stopping power value for that gas. Deviations in y-bar/sub F/ and y-bar/sub D/ are calculated for 60 Co using different extrapolation procedures from 0.15 keV/μm to zero event size. These deviations can be as large as 30%. Advantages of reporting microdosimetric parameters such as y-bar/sub F/ and y-bar/sub D/ above a certain minimum cut-off are discussed

  18. E143 experiment. Shower counter calibration

    International Nuclear Information System (INIS)

    Fonvieille, H.; Grenier, P.

    1994-01-01

    The calibration procedure for the shower counters used in the E143 experiment is described. It has been developed during january 1994 in view of being used for the quick analysis. The method is explained and the results obtained on a given run are presented. (author)

  19. Programmable Quantum Photonic Processor Using Silicon Photonics

    Science.gov (United States)

    2017-04-01

    8 Figure 6: (a) Proposed on-demand single photon source based on dynamic cavity storage . (b) Example of a gate implementation...electronic architectures tuned to implement artificial neural networks that improve upon both computational speed and energy efficiency. 3.6 All...states are in the dual- rail logic representation. Approved for Public Release; Distribution Unlimited. 6 Figure 3: Schematic of two-photon

  20. Nonlinear silicon photonics

    Science.gov (United States)

    Borghi, M.; Castellan, C.; Signorini, S.; Trenti, A.; Pavesi, L.

    2017-09-01

    Silicon photonics is a technology based on fabricating integrated optical circuits by using the same paradigms as the dominant electronics industry. After twenty years of fervid development, silicon photonics is entering the market with low cost, high performance and mass-manufacturable optical devices. Until now, most silicon photonic devices have been based on linear optical effects, despite the many phenomenologies associated with nonlinear optics in both bulk materials and integrated waveguides. Silicon and silicon-based materials have strong optical nonlinearities which are enhanced in integrated devices by the small cross-section of the high-index contrast silicon waveguides or photonic crystals. Here the photons are made to strongly interact with the medium where they propagate. This is the central argument of nonlinear silicon photonics. It is the aim of this review to describe the state-of-the-art in the field. Starting from the basic nonlinearities in a silicon waveguide or in optical resonator geometries, many phenomena and applications are described—including frequency generation, frequency conversion, frequency-comb generation, supercontinuum generation, soliton formation, temporal imaging and time lensing, Raman lasing, and comb spectroscopy. Emerging quantum photonics applications, such as entangled photon sources, heralded single-photon sources and integrated quantum photonic circuits are also addressed at the end of this review.

  1. Single-photon sources

    International Nuclear Information System (INIS)

    Lounis, Brahim; Orrit, Michel

    2005-01-01

    The concept of the photon, central to Einstein's explanation of the photoelectric effect, is exactly 100 years old. Yet, while photons have been detected individually for more than 50 years, devices producing individual photons on demand have only appeared in the last few years. New concepts for single-photon sources, or 'photon guns', have originated from recent progress in the optical detection, characterization and manipulation of single quantum objects. Single emitters usually deliver photons one at a time. This so-called antibunching of emitted photons can arise from various mechanisms, but ensures that the probability of obtaining two or more photons at the same time remains negligible. We briefly recall basic concepts in quantum optics and discuss potential applications of single-photon states to optical processing of quantum information: cryptography, computing and communication. A photon gun's properties are significantly improved by coupling it to a resonant cavity mode, either in the Purcell or strong-coupling regimes. We briefly recall early production of single photons with atomic beams, and the operation principles of macroscopic parametric sources, which are used in an overwhelming majority of quantum-optical experiments. We then review the photophysical and spectroscopic properties and compare the advantages and weaknesses of various single nanometre-scale objects used as single-photon sources: atoms or ions in the gas phase and, in condensed matter, organic molecules, defect centres, semiconductor nanocrystals and heterostructures. As new generations of sources are developed, coupling to cavities and nano-fabrication techniques lead to improved characteristics, delivery rates and spectral ranges. Judging from the brisk pace of recent progress, we expect single photons to soon proceed from demonstrations to applications and to bring with them the first practical uses of quantum information

  2. Extensive tests of Hybrid Photon Detectors (HPD) used to collect Cherenkov light

    International Nuclear Information System (INIS)

    Borsato, E.; Buccheri, A.; DalCorso, F.; Ferroni, F.; Iacovella, F.; Mazzoni, M.A.; Morandin, M.; Morganti, S.; Piredda, G.; Posocco, M.; Santacesaria, R.; Stroili, R.; Torassa, E.; Voci, C.

    1997-01-01

    The principle of operation of a newly developed proximity focused Hybrid Photon Detector is described. The HPD characteristics, performance and calibration are reported. Results from beam tests of aerogel threshold counters read out by HPD and the particle identification performance are presented. (orig.)

  3. Israel's Counter-Terrorism Strategy and its Effectiveness

    National Research Council Canada - National Science Library

    Smith, Jerry D

    2005-01-01

    This thesis analyzes Israeli counter-terrorism strategy and its effectiveness. Because of ongoing suicide attacks from Palestinian and other terrorist organizations, Israel will continue to have an aggressive counter-terrorism strategy...

  4. 21 CFR 866.2180 - Manual colony counter.

    Science.gov (United States)

    2010-04-01

    ...) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2180 Manual colony counter. (a) Identification. A manual colony counter is a device intended for medical purposes that consists...

  5. Single-photon imaging

    CERN Document Server

    Seitz, Peter

    2011-01-01

    The acquisition and interpretation of images is a central capability in almost all scientific and technological domains. In particular, the acquisition of electromagnetic radiation, in the form of visible light, UV, infrared, X-ray, etc. is of enormous practical importance. The ultimate sensitivity in electronic imaging is the detection of individual photons. With this book, the first comprehensive review of all aspects of single-photon electronic imaging has been created. Topics include theoretical basics, semiconductor fabrication, single-photon detection principles, imager design and applications of different spectral domains. Today, the solid-state fabrication capabilities for several types of image sensors has advanced to a point, where uncoooled single-photon electronic imaging will soon become a consumer product. This book is giving a specialist´s view from different domains to the forthcoming “single-photon imaging” revolution. The various aspects of single-photon imaging are treated by internati...

  6. Heavy quark pair production in polarized photon-photon collisions

    International Nuclear Information System (INIS)

    Jikia, G.; Tkabladze, A.

    2000-04-01

    We present the cross sections of the heavy quark-antiquark pair production in polarized photon photon collision for the general case of photon polarizations. The numerical results for top-antitop production cross sections together with production asymmetries are obtained for linearly polarized photon-photon collisions, including QCD radiative corrections. (orig.)

  7. Photonics in South Africa

    CSIR Research Space (South Africa)

    Bollig, C

    2007-12-01

    Full Text Available : photonics, ultrafast and ultra- intense laser science (Heinrich Schwoerer, University of Stellenbosch); quantum information processing and communication (Francesco Petruccione, University of KwaZulu-Natal); medicinal chemistry and nanotechnology... of experience in diamond research, where scientists are now turning their attention to diamond for photonic devices. �ere is an active community in South Africa studying the potential of diamond as a single-photon source for applications in quantum...

  8. Integrated Microwave Photonics

    OpenAIRE

    Marpaung, David; Roeloffzen, Chris; Heideman, René; Leinse, Arne; Sales Maicas, Salvador; Capmany Francoy, José

    2013-01-01

    Microwave photonics (MWP) is an emerging field in which radio frequency (RF) signals are generated, distributed, processed and analyzed using the strength of photonic techniques. It is a technology that enables various functionalities which are not feasible to achieve only in the microwave domain. A particular aspect that recently gains significant interests is the use of photonic integrated circuit (PIC) technology in the MWP field for enhanced functionalities and robustness as well as the r...

  9. Two-photon physics

    International Nuclear Information System (INIS)

    Bardeen, W.A.

    1981-10-01

    A new experimental frontier has recently been opened to the study of two photon processes. The first results of many aspects of these reactions are being presented at this conference. In contrast, the theoretical development of research ito two photon processes has a much longer history. This talk reviews the many different theoretical ideas which provide a detailed framework for our understanding of two photon processes

  10. Photon detector for high energy measurements in the SELEX spectrometer (Fermilab experiment E781)

    International Nuclear Information System (INIS)

    Goncharenko, Yu.M.; Grachov, O.A.; Kurshetsov, V.F.; Landsberg, L.G.; Nurushev, S.B.; Vasil'ev, A.N.

    1995-01-01

    A possibility to use one- or two-photon lead glass detectors for high energy measurements in the SELEX spectrometer with E γ up to 500 GeV is studied. It is shown that a single photon detector equipped with radiation-resistant lead glass counters is applicable for the experiment discussed. It is concluded that for the best energy resolution in the case of Primakoff effect like π - = γ * → π - + γ the combined method would be used with weighted combination of direct E γ measurement in the Photon-3 detector and the π - beam energy precise measurement. 11 refs., 4 tabs., 17 figs

  11. Efficiency calibration of solid track spark auto counter

    International Nuclear Information System (INIS)

    Wang Mei; Wen Zhongwei; Lin Jufang; Liu Rong; Jiang Li; Lu Xinxin; Zhu Tonghua

    2008-01-01

    The factors influencing detection efficiency of solid track spark auto counter were analyzed, and the best etch condition and parameters of charge were also reconfirmed. With small plate fission ionization chamber, the efficiency of solid track spark auto counter at various experiment assemblies was re-calibrated. The efficiency of solid track spark auto counter at various experimental conditions was obtained. (authors)

  12. Counter-responses as organizers in adolescent analysis and therapy.

    Science.gov (United States)

    Richmond, M Barrie

    2004-01-01

    The author introduces Counter-response as a phenomological term to replace theory-burdened terms like counter-transference, counter-identification, and counter-resistance. He discusses the analyst's use of self (drawing on the comparison with Winnicott's use of the object) in processing the expectable destabilizing counter-reactions that occur in working therapeutically with disturbed adolescents and their parents. Further; he discusses the counter-reaction to the patient's narrative, acting-out, and how re-enactments can serve as an organizer for understanding the patient's inner life when the analyst formulates his/her counter-response. Emphasis is placed on the therapist forming his or her own narrative with the adolescent that takes into account the evoked counter-reaction. For this purpose, the author recommends the use of a combined counter-response and metaphor-orienting perspective to acknowledge and work with the denial, illusions, reversal of perspective, and catastrophic anxieties experienced with these adolescents. The counter-response perspective permits the emergence of the disturbed adolescent's novel narrative; however, since these experiences can be destabilizing or disruptive, the author also recommends the use of a personal metaphor to anticipate the reluctance to examining, processing, and formulating the analyst's dysphoric counter-reaction. With the use of the counter-response, the analyst's therapeutic ideal is to achieve a more optimal balance between using accepted narrative theories and exploring novel enactment experiences. His swimming metaphor stratagem is designed to keep the analyst in these difficult encounters.

  13. Generalization of the development of liquid-sparkling counter

    International Nuclear Information System (INIS)

    Bian Zhengzhu; Zhang Jue; Zhang Jinwei

    2006-01-01

    This paper includes five parts. It not only reviews the development history of liquid-sparkling counter but refers that the appearance of coincident circuit is its milestone. The paper summarizes the resembled hard ware and soft ware and soft ware of liquid-sparkling counter of indoor and overseas, and prospects the development of liquid-sparkling counter in our country. (authors)

  14. Review on Dark Photon

    Directory of Open Access Journals (Sweden)

    Curciarello Francesca

    2016-01-01

    Full Text Available e+e− collider experiments at the intensity frontier are naturally suited to probe the existence of a force beyond the Standard Model between WIMPs, the most viable dark matter candidates. The mediator of this new force, known as dark photon, should be a new vector gauge boson very weakly coupled to the Standard Model photon. No significant signal has been observed so far. I will report on current limits set on the coupling factor ε2 between the photon and the dark photon by e+e− collider experiments.

  15. Towards THz integrated photonics

    OpenAIRE

    Hübers, Heinz-Wilhelm

    2010-01-01

    The demonstration of an integrated terahertz transceiver featuring a quantum cascade laser and a Schottky diode mixer promises new applications for compact and convenient terahertz photonic instrumentation.

  16. Tale of two photons

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    A very profitable spinoff from electron- positron collisions is two-photon physics. Rather than the electron and positron interacting directly via an exchanged photon, two virtual (transient) photons, one from each particle, get tangled up. With new electron-positron colliders appearing on the scene, a topical meeting on two-photon physics - 'From DAPHNE to LEP 200 and beyond' - held from 2-4 February in Paris, in the premises of the Ministry of Higher Education and Research, was particularly timely. Some 60 physicists, both experimentalists and theorists, participated, with some thirty speakers

  17. Advanced Photon Source (APS)

    Data.gov (United States)

    Federal Laboratory Consortium — The Advanced Photon Source (APS) at the U.S. Department of Energy's Argonne National Laboratoryprovides this nation's (in fact, this hemisphere's) brightest storage...

  18. Photonic Integrated Circuits

    Science.gov (United States)

    Krainak, Michael; Merritt, Scott

    2016-01-01

    Integrated photonics generally is the integration of multiple lithographically defined photonic and electronic components and devices (e.g. lasers, detectors, waveguides passive structures, modulators, electronic control and optical interconnects) on a single platform with nanometer-scale feature sizes. The development of photonic integrated circuits permits size, weight, power and cost reductions for spacecraft microprocessors, optical communication, processor buses, advanced data processing, and integrated optic science instrument optical systems, subsystems and components. This is particularly critical for small spacecraft platforms. We will give an overview of some NASA applications for integrated photonics.

  19. Single photon emission tomography

    International Nuclear Information System (INIS)

    Buvat, Irene

    2011-09-01

    The objective of this lecture is to present the single photon emission computed tomography (SPECT) imaging technique. Content: 1 - Introduction: anatomic, functional and molecular imaging; Principle and role of functional or molecular imaging; 2 - Radiotracers: chemical and physical constraints, main emitters, radioisotopes production, emitters type and imaging techniques; 3 - Single photon emission computed tomography: gamma cameras and their components, gamma camera specifications, planar single photon imaging characteristics, gamma camera and tomography; 4 - Quantification in single photon emission tomography: attenuation, scattering, un-stationary spatial resolution, partial volume effect, movements, others; 5 - Synthesis and conclusion

  20. Photon virtual bound state

    International Nuclear Information System (INIS)

    Inoue, J.; Ohtaka, K.

    2004-01-01

    We study virtual bound states in photonics, which are a vectorial extension of electron virtual bound states. The condition for these states is derived. It is found that the Mie resonant state which satisfies the condition that the size parameter is less than the angular momentum should be interpreted as a photon virtual bound state. In order to confirm the validity of the concept, we compare the photonic density of states, the width of which represents the lifetime of the photon virtual bound states, with numerical results

  1. Biomedical photonics handbook

    CERN Document Server

    Vo-Dinh, Tuan

    2003-01-01

    1.Biomedical Photonics: A Revolution at the Interface of Science and Technology, T. Vo-DinhPHOTONICS AND TISSUE OPTICS2.Optical Properties of Tissues, J. Mobley and T. Vo-Dinh3.Light-Tissue Interactions, V.V. Tuchin 4.Theoretical Models and Algorithms in Optical Diffusion Tomography, S.J. Norton and T. Vo-DinhPHOTONIC DEVICES5.Laser Light in Biomedicine and the Life Sciences: From the Present to the Future, V.S. Letokhov6.Basic Instrumentation in Photonics, T. Vo-Dinh7.Optical Fibers and Waveguides for Medical Applications, I. Gannot and

  2. A new neutron counter for fission research

    Energy Technology Data Exchange (ETDEWEB)

    Laurent, B., E-mail: benoit.laurent@cea.fr [CEA, DAM, DIF, F-91297 Arpajon (France); Granier, T.; Bélier, G.; Chatillon, A.; Martin, J.-F.; Taieb, J. [CEA, DAM, DIF, F-91297 Arpajon (France); Hambsch, F.-J. [EC-JRC Institute for Reference Materials and Measurements (IRMM), Retieseweg, 2440 Geel (Belgium); Tovesson, F.; Laptev, A.B.; Haight, R.C.; Nelson, R.O.; O' Donnell, J.M. [Los Alamos Neutron Science Center, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2014-05-01

    A new neutron counter for research experiments on nuclear fission has been developed. This instrument is designed for the detection of prompt fission neutrons within relatively high levels of gamma and neutron background. It is composed of a set of {sup 3}He proportional counters arranged within a block of polyethylene which serves as moderator. The detection properties have been studied by means of Monte Carlo simulations and experiments with radioactive sources. These properties are confirmed by an experiment on neutron-induced fission of {sup 238}U at the WNR facility of the Los Alamos Neutron Science Center during which the mean prompt fission neutron multiplicity, or ν{sup ¯} has been measured from 1 to 20 MeV of incident neutron energy.

  3. Dead zone characteristics of a gas counter

    International Nuclear Information System (INIS)

    Nohtomi, Akihiro; Sakae, Takeji; Matoba, Masaru; Koori, Norihiko.

    1990-01-01

    The dead zone was recently defined as the product of dead length and dead time in order to describe the characteristics of the self-quenching streamer (SQS) mode of a gas counter. Investigation of the dead zone characteristics has been extended for the proportional and GM modes, and the measured dead zone has been compared with that of the SQS mode. Accurate values for the dead zone could be determined by means of a newly developed method with a pulse interval time to amplitude converter. Each operation mode indicates distinct dead zone characteristics. Properties of gas counters for high counting rates may be improved on the basis of measurements of the dead zone. (author)

  4. Pulse triggering mechanism of air proportional counters

    International Nuclear Information System (INIS)

    Aoyama, T.; Mori, T.; Watanabe, T.

    1983-01-01

    This paper describes the pulse triggering mechanism of a cylindrical proportional counter filled with air at atmospheric pressure for the incidence of β-rays. Experimental results indicate that primary electrons created distantly from the anode wire by a β-ray are transformed into negative ions, which then detach electrons close to the anode wire and generate electron avalanches thus triggering pulses, while electrons created near the anode wire by a β-ray directly trigger a pulse. Since a negative ion pulse is triggered by a single electron detached from a negative ion, multiple pulses are generated by a large number of ions produced by the incidence of a single β-ray. It is therefore necessary not to count pulses triggered by negative ions but to count those by primary electrons alone when use is made of air proportional counters for the detection of β-rays. (orig.)

  5. Sources of Brazil's Counter-Hegemony

    Directory of Open Access Journals (Sweden)

    Marcos Aurelio Guedes de Oliveira

    2010-01-01

    Full Text Available There have been two key initiatives taken in the last two decades in Brazil to create a counter-hegemonic project for the country. One initiative resulted from Brazil's business community and high-level State bureaucracy and aimed at forming a regional economic and political bloc that would guarantee and enlarge a relative independence from the hegemonic powers. The other resulted from the emergence of the new unionist movement in São Paulo and from the formation of Partido dos Trabalhadores and aimed at promoting radical democratization and reducing social exclusion. Both initiatives have created policies and changes that have converged to enhance Brazil's counter-hegemonic position as a regional and emerging power.

  6. Very large area multiwire spectroscopic proportional counters

    International Nuclear Information System (INIS)

    Ubertini, P.; Bazzano, A.; Boccaccini, L.; Mastropietro, M.; La Padula, C.D.; Patriarca, R.; Polcaro, V.F.

    1981-01-01

    As a result of a five year development program, a final prototype of a Very Large Area Spectroscopic Proportional Counter (VLASPC), to be employed in space borne payloads, was produced at the Istituto di Astrofisica Spaziale, Frascati. The instrument is the last version of a new generation of Multiwire Spectroscopic Proportional Counters (MWSPC) succesfully employed in many balloon borne flights, devoted to hard X-ray astronomy. The sensitive area of this standard unit is 2700 cm 2 with an efficiency higher than 10% in the range 15-180 keV (80% at 60 keV). The low cost and weight make this new type of VLASPC competitive with Nal arrays, phoswich and GSPC detectors in terms of achievable scientific results. (orig.)

  7. Very large area multiwire spectroscopic proportional counters

    Energy Technology Data Exchange (ETDEWEB)

    Ubertini, P.; Bazzano, A.; Boccaccini, L.; Mastropietro, M.; La Padula, C.D.; Patriarca, R.; Polcaro, V.F. (Istituto di Astrofisica Spaziale, Frascati (Italy))

    1981-07-01

    As a result of a five year development program, a final prototype of a Very Large Area Spectroscopic Proportional Counter (VLASPC), to be employed in space borne payloads, was produced at the Istituto di Astrofisica Spaziale, Frascati. The instrument is the last version of a new generation of Multiwire Spectroscopic Proportional Counters (MWSPC) successfully employed in many balloon borne flights, devoted to hard X-ray astronomy. The sensitive area of this standard unit is 2700 cm/sup 2/ with an efficiency higher than 10% in the range 15-180 keV (80% at 60 keV). The low cost and weight make this new type of VLASPC competitive with Nal arrays, phoswich and GSPC detectors in terms of achievable scientific results.

  8. Calibration of the neutron scintillation counter threshold

    International Nuclear Information System (INIS)

    Noga, V.I.; Ranyuk, Yu.N.; Telegin, Yu.N.

    1978-01-01

    A method for calibrating the threshold of a neutron counter in the form of a 10x10x40 cm plastic scintillator is described. The method is based on the evaluation of the Compton boundary of γ-spectrum from the discrimination curve of counter loading. The results of calibration using 60 Co and 24 Na γ-sources are given. In order to eValuate the Compton edge rapidly, linear extrapolation of the linear part of the discrimination curve towards its intersection with the X axis is recommended. Special measurements have shown that the calibration results do not practically depend on the distance between the cathode of a photomultiplier and the place where collimated γ-radiation of the calibration source reaches the scintillator

  9. Engaging Civil Society in Countering Violent Extremism

    Directory of Open Access Journals (Sweden)

    Bibi van Ginkel

    2012-08-01

    Full Text Available In this Research Paper Dr. Bibi van Ginkel takes an in depth look at how multi-lateral institutions, engage with civil society to counter violent extremism. Dr. van Ginkel argues that civil society can play a crucial role in preventing and countering violent extremism in numerous ways – by working on development programs, through their work in conflict transformation, in providing a platform to raise political grievances and to facilitate dialogue, or through their work in empowering victims and survivors of terrorism. The Paper finds that over the last decade there has been a more intensive coordination of activities between the UN and other multi-lateral organisations and civil society but the question remains whether the implementation as well as the drafting of these policies will live up to their potential effectiveness. This Paper gauges how effective these measures have been and what more there is to do. The final section concludes with a series of policy recommendations.

  10. A position sensitive parallel plate avalanche counter

    International Nuclear Information System (INIS)

    Lombardi, M.; Tan Jilian; Potenza, R.; D'amico, V.

    1986-01-01

    A position sensitive parallel plate avalanche counter with a distributed constant delay-line-cathode (PSAC) is described. The strips formed on the printed board were served as the cathode and the delay line for readout of signals. The detector (PSAC) was operated in isobutane gas at the pressure range from 10 to 20 torr. The position resolution is better than 1 mm and the time resolution is about 350 ps, for 252 Cf fission-spectrum source

  11. Evaluating the US Counter-ISIL Strategy

    Science.gov (United States)

    2017-05-25

    strategy is actually addressing those critical capabilities and vulnerabilities. Finally, it explores alternative, whole-of-government strategies that...Counterterrorism Strategies as an Illustration. Santa Monica, CA: RAND Corporation , 2009. Enduring Leadership in a Dynamic World. Quadrennial Diplomacy...Evaluating the US Counter-ISIL Strategy A Monograph by LTC Jason A. Curl U.S. Army School of Advanced Military Studies United States Army

  12. Universal Fast Breeder Reactor Subassembly Counter manual

    International Nuclear Information System (INIS)

    Menlove, H.O.; Eccleston, G.W.; Swansen, J.E.; Goris, P.; Abedin-Zadeh, R.; Ramalho, A.

    1984-08-01

    A neutron coincidence counter has been designed for the measurement of fast breeder reactor fuel assemblies. This assay system can accommodate the full range of geometries and masses found in fast breeder subassemblies under IAEA safeguards. The system's high-performance capability accommodates high plutonium loadings of up to 16 kg. This manual describes the system and its operation and gives performance and calibration parameters for typical applications

  13. Universal Fast Breeder Reactor Subassembly Counter manual

    Energy Technology Data Exchange (ETDEWEB)

    Menlove, H.O.; Eccleston, G.W.; Swansen, J.E.; Goris, P.; Abedin-Zadeh, R.; Ramalho, A.

    1984-08-01

    A neutron coincidence counter has been designed for the measurement of fast breeder reactor fuel assemblies. This assay system can accommodate the full range of geometries and masses found in fast breeder subassemblies under IAEA safeguards. The system's high-performance capability accommodates high plutonium loadings of up to 16 kg. This manual describes the system and its operation and gives performance and calibration parameters for typical applications.

  14. Photon-phonon interaction in photonic crystals

    International Nuclear Information System (INIS)

    Ueta, T

    2010-01-01

    Photon-phonon interaction on the analogy of electron-phonon interaction is considered in one-dimensional photonic crystal. When lattice vibration is artificially introduced to the photonic crystal, a governing equation of electromagnetic field is derived. A simple model is numerically analysed and the following novel phenomena are found out. The lattice vibration generates the light of frequency which added the integral multiple of the vibration frequency to that of the incident wave and also amplifies the incident wave resonantly. On a resonance, the amplification factor increases very rapidly with the number of layers increases. Resonance frequencies change with the phases of lattice vibration. The amplification phenomenon is analytically discussed for low frequency of the lattice vibration.

  15. Development of aerogel Cherenkov counters at Novosibirsk

    International Nuclear Information System (INIS)

    Barnyakov, A.Yu.; Barnyakov, M.Yu.; Baehr, J.; Bellunato, T.; Beloborodov, K.I.; Bobrovnikov, V.S.; Buzykaev, A.R.; Calvi, M.; Danilyuk, A.F.; Djordjadze, V.; Golubev, V.B.; Kononov, S.A.; Kravchenko, E.A.; Lipka, D.; Matteuzzi, C.; Musy, M.; Onuchin, A.P.; Perego, D.; Rodiakin, V.A.; Savinov, G.A.; Serednyakov, S.I.; Shamov, A.G.; Stephan, F.; Tayursky, V.A.; Vorobiov, A.I.

    2006-01-01

    The work on aerogel Cherenkov counters was started in Novosibirsk in 1986. Production of aerogels with refractive indices of 1.006-1.13 and thicknesses of blocks up to 50mm was developed. The light absorption length at 400nm is 5-7m, the scattering length is 4-5cm. By these parameters, the Novosibirsk aerogel is one of the best in the world. The ASHIPH Cherenkov counters with light collection on wavelength shifters have been developed. The ASHIPH system of the KEDR detector contains 1000l of aerogel. The π/K separation is 4.5σ. A project of ASHIPH counters for the SND detector has been developed. Aerogel RICH for LHCb gives a possibility to identify hadrons in the momentum range of 2-10GeV/c. The Novosibirsk group is developing an aerogel RICH for the endcap for the SuperBaBar project. Calculations performed by a group of physicists from Novosibirsk and DESY-Zeuthen have shown that aerogel radiators enable to achieve time resolution up to 20fs

  16. Which future for nuclear counter-proliferation?

    International Nuclear Information System (INIS)

    Duval, M.

    2010-01-01

    Dealing with the case of nuclear weapons possessed by nuclear states (but not eventually by terrorists), the author first identifies the constants of counter-proliferation: it is linked to interest conflicts between those who try to preserve their monopoly and those who try to acquire a new weapon either because of a threat or for reasons of regional prestige, the evolution from use to deterrence, the appearance of new actors after the USA and Russia, the role of nuclear tactical weapons, and the future of Russian weapons and know-how. He presents the international counter-proliferation context: the Non Proliferation Treaty (NPT), the IAEA and its controls, the Nuclear Supplier Group (NSG), the nuclear-free zones, the Comprehensive Test Ban Treaty (CTBT), the Missile Technology Control Regime (MTCR). He describes how and why proliferation occurs: uranium enrichment and plutonium technology, political reasons in different parts of the world. Then, he gives an overview of the proliferation status by commenting the cases of Israel, Iraq, India, Pakistan, North Korea, and Iran. He discusses the future of proliferation (involved countries, existence of a nuclear black market) and of counter-proliferation as far as Middle-East and North Korea are concerned. He tries finally to anticipate the consequences for nuclear deterrence strategy, and more particularly for Europe and France

  17. A neutron calibration technique for detectors with low neutron/high photon sensitivity

    International Nuclear Information System (INIS)

    Jahr, R.; Guldbakke, S.; Cosack, M.; Dietze, G.; Klein, H.

    1978-03-01

    The neutron response of a detector with low neutron-/high photon sensitivity is given by the difference of two terms: the response to the mixed neutron-photon field, measured directly, and the response to the photons, deduced from additional measurements with a photon spectrometer. The technique is particularly suited for use in connection with targets which consist of a thick backing and thin layer of neutron producing material such as T, D, Li nuclei. Then the photon component of the mixed field is very nearly the same as the pure photon field from a 'phantom target', being identical with the neutron producing target except for the missing neutron producing material. Using this technique in connection with a T target (Ti-T-layer on silver backing) and the corresponding phantom target (Ti-layer on silver backing), a GM counter was calibrated at a neutron energy of 2.5 MeV. Possibilities are discussed to subsequently calibrate the GM counter at other neutron energies without the use of the photon spectrometer. (orig./HP) [de

  18. A novel high-performance counter electrode for dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Wang Guiqiang; Lin Ruifeng; Lin Yuan; Li Xueping; Zhou Xiaowen; Xiao Xurui

    2005-01-01

    A novel Pt counter electrode for dye-sensitized solar cells (DSC) was prepared by thermal decomposition of H 2 PtCl 6 on NiP-plated glass substrate. The charge-transfer kinetic properties of the platinized NiP-plated glass electrode (Pt/NiP electrode) for triiodide reduction were studied by electrochemical impedance spectroscopy. Pt/NiP electrode has the advantage over the platinized FTO conducting glass electrode (Pt/FTO electrode) in increasing the light reflectance and reducing the sheet resistance leading to improve the light harvest efficiency and the fill factor of the dye-sensitized solar cells effectively. The photon-to-current efficiency and the overall conversion efficiency of DSC using Pt/NiP counter electrode is increased by 20% and 33%, respectively, compared to that of using Pt/FTO counter electrode. Examination of the anodic dissolution and the long-term test on the variation of charge-transfer resistance indicates the good stability of the Pt/NiP electrode in the electrolyte containing iodide/triiodide

  19. Photon blockade in optomechanical systems with a position-modulated Kerr-type nonlinear coupling

    Science.gov (United States)

    Zhang, X. Y.; Zhou, Y. H.; Guo, Y. Q.; Yi, X. X.

    2018-03-01

    We explore the photon blockade in optomechanical systems with a position-modulated Kerr-type nonlinear coupling, i.e. H_int˜\\hat{a}\\dagger2\\hat{a}^2(\\hat{b}_1^\\dagger+\\hat{b}_1) . We find that the Kerr-type nonlinear coupling can enhance the photon blockade greatly. We evaluate the equal-time second-order correlation function of the cavity photons and find that the optimal photon blockade does not happen at the single photon resonance. By working within the few-photon subspace, we get an approximate analytical expression for the correlation function and the condition for the optimal photon blockade. We also find that the photon blockade effect is not always enhanced as the Kerr-type nonlinear coupling strength g 2 increases. At some values of g 2, the photon blockade is even weakened. For the system we considered here, the second-order correlation function can be smaller than 1 even in the unresolved sideband regime. By numerically simulating the master equation of the system, we also find that the thermal noise of the mechanical environment can enhance the photon blockade. We give out an explanation for this counter-intuitive phenomenon qualitatively.

  20. ALICE Photon Multiplicity Detector

    CERN Multimedia

    Nayak, T

    2013-01-01

    Photon Multiplicity Detector (PMD) measures the multiplicity and spatial distribution of photons in the forward region of ALICE on a event-by-event basis. PMD is a pre-shower detector having fine granularity and full azimuthal coverage in the pseudo-rapidity region 2.3 < η < 3.9.

  1. Diffusion Based Photon Mapping

    DEFF Research Database (Denmark)

    Schjøth, Lars; Sporring, Jon; Fogh Olsen, Ole

    2008-01-01

    . To address this problem, we introduce a photon mapping algorithm based on nonlinear anisotropic diffusion. Our algorithm adapts according to the structure of the photon map such that smoothing occurs along edges and structures and not across. In this way, we preserve important illumination features, while...

  2. Integrated microwave photonics

    NARCIS (Netherlands)

    Marpaung, D.A.I.; Roeloffzen, C.G.H.; Heideman, Rene; Leinse, Arne; Sales, S.; Capmany, J.

    2013-01-01

    Microwave photonics (MWP) is an emerging field in which radio frequency (RF) signals are generated, distributed, processed and analyzed using the strength of photonic techniques. It is a technology that enables various functionalities which are not feasible to achieve only in the microwave domain. A

  3. Two Photon Distribution Amplitudes

    International Nuclear Information System (INIS)

    El Beiyad, M.; Pire, B.; Szymanowski, L.; Wallon, S.

    2008-01-01

    The factorization of the amplitude of the process γ*γ→γγ in the low energy and high photon virtuality region is demonstrated at the Born order and in the leading logarithmic approximation. The leading order two photon (generalized) distribution amplitudes exhibit a characteristic ln Q 2 behaviour and obey new inhomogeneous evolution equations

  4. Agile Photonic Crystals

    Science.gov (United States)

    2011-01-03

    75, pp. 3253-3256, Oct. 1995. [24] F. Benabid, J. C. Knight, and P. S. J. Russell, “Particle levitation and guidance in hollow-core photonic crystal...B. Mizaikoff, “Midinfrared sensors meet nanotechnology: Trace gas sensing with quantum cascade lasers inside photonic band-gap hollow waveguides

  5. Photon beam position monitor

    Science.gov (United States)

    Kuzay, Tuncer M.; Shu, Deming

    1995-01-01

    A photon beam position monitor for use in the front end of a beamline of a high heat flux and high energy photon source such as a synchrotron radiation storage ring detects and measures the position and, when a pair of such monitors are used in tandem, the slope of a photon beam emanating from an insertion device such as a wiggler or an undulator inserted in the straight sections of the ring. The photon beam position monitor includes a plurality of spaced blades for precisely locating the photon beam, with each blade comprised of chemical vapor deposition (CVD) diamond with an outer metal coating of a photon sensitive metal such as tungsten, molybdenum, etc., which combination emits electrons when a high energy photon beam is incident upon the blade. Two such monitors are contemplated for use in the front end of the beamline, with the two monitors having vertically and horizontally offset detector blades to avoid blade "shadowing". Provision is made for aligning the detector blades with the photon beam and limiting detector blade temperature during operation.

  6. Superconducting Single Photon Detectors

    NARCIS (Netherlands)

    Dorenbos, S.N.

    2011-01-01

    This thesis is about the development of a detector for single photons, particles of light. New techniques are being developed that require high performance single photon detection, such as quantum cryptography, single molecule detection, optical radar, ballistic imaging, circuit testing and

  7. Hardware support for software controlled fast multiplexing of performance counters

    Science.gov (United States)

    Salapura, Valentina; Wisniewski, Robert W.

    2013-01-01

    Performance counters may be operable to collect one or more counts of one or more selected activities, and registers may be operable to store a set of performance counter configurations. A state machine may be operable to automatically select a register from the registers for reconfiguring the one or more performance counters in response to receiving a first signal. The state machine may be further operable to reconfigure the one or more performance counters based on a configuration specified in the selected register. The state machine yet further may be operable to copy data in selected one or more of the performance counters to a memory location, or to copy data from the memory location to the counters, in response to receiving a second signal. The state machine may be operable to store or restore the counter values and state machine configuration in response to a context switch event.

  8. Photonics in wireless transceivers

    International Nuclear Information System (INIS)

    Bogani, A.; Ghelfi, P.

    2013-01-01

    During the last few years, the cross-fertilization between photonics and radio systems has been helping to overcome some major limitations of the classical radio technologies, setting new paradigms, and promising improved performance and new applications with strong benefits for public communications and safety. In particular, photonics-based wireless systems, albeit still at research level, are moving toward a new generation of multifunctional systems able to manage the wireless communication with several different frequencies and protocols, even simultaneously while also realizing surveillance operations. Photonics matches the new requirements of flexibility for software-defined architectures, thanks to its ultra-wide bandwidths and ease of tunability, and guarantees low footprint and weight, thanks to integrated photonic technologies. Moreover, photonics also allows increased resolution and sensitivity by means of the inherent low phase noise of lasers. (author)

  9. Nonlinear Photonics 2014: introduction.

    Science.gov (United States)

    Akhmediev, N; Kartashov, Yaroslav

    2015-01-12

    International Conference "Nonlinear Photonics-2014" took place in Barcelona, Spain on July 27-31, 2014. It was a part of the "Advanced Photonics Congress" which is becoming a traditional notable event in the world of photonics. The current focus issue of Optics Express contains contributions from the participants of the Conference and the Congress. The articles in this focus issue by no means represent the total number of the congress contributions (around 400). However, it demonstrates wide range of topics covered at the event. The next conference of this series is to be held in 2016 in Australia, which is the home of many researchers working in the field of photonics in general and nonlinear photonics in particular.

  10. A high energy photon detector system in compact form

    International Nuclear Information System (INIS)

    Kato, Sadayuki; Sugano, Katsuhito; Yoshioka, Masakazu.

    1975-01-01

    The development of a high energy photon detector system in compact form for use in experiments of high energy physics is described, and the results of its characteristics calibrated using converted electron beams and a pair spectrometer are reported. This system consists of a total absorption lead glass Cerenkov counter, twenty hodoscope arrays for the vertical and the horizontal directions respectively, a lead plate for the conversion of γ-rays into electron-positron pairs, veto counters, photon hardener, and lead blocks for shieldings and collimation. The spatial resolution of the hodoscope is 15 mm for each direction, covering 301 x 301 mm 2 area. The energy resolution of the total absorption lead glass Cerenkov counter, whose volume is 30 x 30 x 30 cm 3 , is typically 18 % (FWHM) for the incident electron energy of 500 MeV, and it can be expressed with a relation of ΔE/E = 3.94 Esup(-1/2). (E in MeV). (auth.)

  11. Photon response of silicon diode neutron detectors

    International Nuclear Information System (INIS)

    McCall, R.C.; Jenkins, T.M.; Oliver, G.D. Jr.

    1976-07-01

    The photon response of silicon diode neutron detectors was studied to solve the problem on detecting neutrons in the presence of high energy photons at accelerator neutron sources. For the experiment Si diodes, Si discs, and moderated activation foil detectors were used. The moderated activation foil detector consisted of a commercial moderator and indium foils 2'' in diameter and approximately 2.7 grams each. The moderator is a cylinder of low-density polyethylene 6 1 / 4 '' in diameter by 6 1 / 16 '' long covered with 0.020'' of cadmium. Neutrons are detected by the reaction 115 In (n,γ) 116 In(T/sub 1 / 2 / = 54 min). Photons cannot be detected directly but photoneutrons produced in the moderator assembly can cause a photon response. The Si discs were thin slices of single-crystal Si about 1.4 mils thick and 1'' in diameter which were used as activation detectors, subsequently being counted on a thin-window pancake G.M. counter. The Si diode fast neutron dosimeter 5422, manufactured by AB Atomenergi in Studsvik, Sweden, consists of a superdoped silicon wafer with a base width of 0.050 inches between two silver contacts coated with 2 mm of epoxy. For this experiment, the technique of measuring the percent change of voltage versus dose was used. Good precision was obtained using both unirradiated and preirradiated diodes. All diodes, calibrated against 252 CF in air,were read out 48 hours after irradiation to account for any room temperature annealing. Results are presented and discussed

  12. Consumer Preferences for High Welfare Meat in Germany: Self-service Counter or Service Counter?

    Directory of Open Access Journals (Sweden)

    Ramona Weinrich

    2015-01-01

    Full Text Available Many people view animal welfare standards in the agricultural industry as critical and some consumers would prefer to buy high welfare meat. In order to successfully introduce high welfare meat products onto the market, some important marketing decisions must be made. Due to limited shelf space in retail outlets, niche products like high welfare meat cannot be placed both at the self-service counter and at the service counter. In order to analyze where to place it best an online survey of 642 German consumers was conducted. By means of factor and cluster analyses, consumers’ animal welfare attitudes and their preference for a point of purchase were combined. The different target groups were joint using cross tabulation analysis. The results reveal that consumers in the target group show a more positive attitude to the service counter.

  13. Counter-Narratives and the Unrehearsed Stories Counter-Terrorists Unwittingly Produce

    Directory of Open Access Journals (Sweden)

    Beatrice de Graaf

    2010-11-01

    Full Text Available Governments produce both deliberate and involuntary (and less conscious narratives when countering terrorism. The thesis of this article is that such unintended messages can be much more powerful and consequential than is realized; in fact, they can completely contradict the intended official 'counter-narrative'. To substantiate this hypothesis, the author looks at the experience of the German Federal Republic in the 1970s and beyond when state and society were confronted with the Red Army Faction (RAF and similar left-wing "revolutionaries" like those of the 2nd of June Movement or the Red Zora.

  14. Progress in neuromorphic photonics

    Science.gov (United States)

    Ferreira de Lima, Thomas; Shastri, Bhavin J.; Tait, Alexander N.; Nahmias, Mitchell A.; Prucnal, Paul R.

    2017-03-01

    As society's appetite for information continues to grow, so does our need to process this information with increasing speed and versatility. Many believe that the one-size-fits-all solution of digital electronics is becoming a limiting factor in certain areas such as data links, cognitive radio, and ultrafast control. Analog photonic devices have found relatively simple signal processing niches where electronics can no longer provide sufficient speed and reconfigurability. Recently, the landscape for commercially manufacturable photonic chips has been changing rapidly and now promises to achieve economies of scale previously enjoyed solely by microelectronics. By bridging the mathematical prowess of artificial neural networks to the underlying physics of optoelectronic devices, neuromorphic photonics could breach new domains of information processing demanding significant complexity, low cost, and unmatched speed. In this article, we review the progress in neuromorphic photonics, focusing on photonic integrated devices. The challenges and design rules for optoelectronic instantiation of artificial neurons are presented. The proposed photonic architecture revolves around the processing network node composed of two parts: a nonlinear element and a network interface. We then survey excitable lasers in the recent literature as candidates for the nonlinear node and microring-resonator weight banks as the network interface. Finally, we compare metrics between neuromorphic electronics and neuromorphic photonics and discuss potential applications.

  15. Beam Cherenkov counter conception for in line identification of 270 GeV/c Σ- Ξ- and Ω-

    International Nuclear Information System (INIS)

    Touillon, R.

    1991-06-01

    The purpose of this thesis is to design a beam Cerenkov counter. This counter will provide an on line identification of the Σ - , Ξ - and Ω - hyperons (270 GeV/c) in the experiment WA89 at CERN. The acceptance of the detector should allow tagging these hyperons in a large momentum range (± 25%) and for a beam divergence up to 250 microrad. The first part of this report is devoted to the physical goals such as the study of charmed baryons, the search of multiquark states, and the determination of hadronic and electromagnetic hyperon radii. The experimental WA89 setup is also presented. The major part deals with the design of the Cerenkov counter. The dimension of the detector, the Cerenkov angle value, the focal length of the spherical mirror, etc... are derived from a Monte-Carlo simulation. Various methods of simple photon detection (gaz detector: TEA, TMAE; solid detectors: PM and Image Intensifier) are investigated. The most performing solution uses two conical mirrors in order to reduce the size of the Cerenkov circles and an image intensifier (which detects the single photon) followed by an optical fiber matrix transmitting the luminous signal to 160 photomultipliers. The on line procedure for calculating the radius of each circle (identification of the particle) is studied in detail. Finally, the optimization of the optical system to achromatize the Cerenkov light is discussed [fr

  16. Total photon absorption

    International Nuclear Information System (INIS)

    Carlos, P.

    1985-06-01

    The present discussion is limited to a presentation of the most recent total photonuclear absorption experiments performed with real photons at intermediate energy, and more precisely in the region of nucleon resonances. The main sources of real photons are briefly reviewed and the experimental procedures used for total photonuclear absorption cross section measurements. The main results obtained below 140 MeV photon energy as well as above 2 GeV are recalled. The experimental study of total photonuclear absorption in the nuclear resonance region (140 MeV< E<2 GeV) is still at its beginning and some results are presented

  17. Photonics: Technology project summary

    Science.gov (United States)

    Depaula, Ramon P.

    1991-01-01

    Photonics involves the use of light (photons) in conjunction with electronics for applications in communications, computing, control, and sensing. Components used in photonic systems include lasers, optical detectors, optical wave guide devices, fiber optics, and traditional electronic devices. The goal of this program is to develop hybrid optoelectronic devices and systems for sensing, information processing, communications, and control. It is hoped that these new devices will yield at least an order of magnitude improvement in performance over existing technology. The objective of the program is to conduct research and development in the following areas: (1) materials and devices; (2) networking and computing; (3) optical processing/advanced pattern recognition; and (4) sensing.

  18. Physics of photonic devices

    CERN Document Server

    Chuang, Shun Lien

    2009-01-01

    The most up-to-date book available on the physics of photonic devices This new edition of Physics of Photonic Devices incorporates significant advancements in the field of photonics that have occurred since publication of the first edition (Physics of Optoelectronic Devices). New topics covered include a brief history of the invention of semiconductor lasers, the Lorentz dipole method and metal plasmas, matrix optics, surface plasma waveguides, optical ring resonators, integrated electroabsorption modulator-lasers, and solar cells. It also introduces exciting new fields of research such as:

  19. Single photon ECT

    International Nuclear Information System (INIS)

    Maeda, Toshio; Matsuda, Hiroshi; Tada, Akira; Bunko, Hisashi; Koizumi, Kiyoshi

    1982-01-01

    The detectability of lesions located deep in a body or overlapped with a physiologically increased activity improve with the help of single photon ECT. In some cases, the ECT is superior to the conventional gamma camera images and X-ray CT scans in the evaluation of the location and size of lesion. The single photon ECT of the brain compares favorably with the contrast enhansed X-ray CT scans. The most important adaptation of the single photon ECT are the detection of recurrent brain tumors after craniotomy and the evaluation of ischemic heart diseases. (author)

  20. Strained Silicon Photonics

    Directory of Open Access Journals (Sweden)

    Ralf B. Wehrspohn

    2012-05-01

    Full Text Available A review of recent progress in the field of strained silicon photonics is presented. The application of strain to waveguide and photonic crystal structures can be used to alter the linear and nonlinear optical properties of these devices. Here, methods for the fabrication of strained devices are summarized and recent examples of linear and nonlinear optical devices are discussed. Furthermore, the relation between strain and the enhancement of the second order nonlinear susceptibility is investigated, which may enable the construction of optically active photonic devices made of silicon.

  1. Photonic Crystal Fibres

    DEFF Research Database (Denmark)

    Bjarklev, Anders Overgaard; Broeng, Jes; Sanchez Bjarklev, Araceli

    Photonic crystal fibres represent one of the most active research areas today in the field of optics. The diversity of applications that may be addressed by these fibres and their fundamental appeal, by opening up the possibility of guiding light in a radically new way compared to conventional...... optical fibres, have spun an interest from almost all areas of optics and photonics. The aim of this book is to provide an understanding of the different types of photonic crystal fibres and to outline some of the many new and exciting applications that these fibres offer. The book is intended for both...

  2. Fundamentals of photonics

    CERN Document Server

    Saleh, Bahaa E A

    2007-01-01

    Now in a new full-color edition, Fundamentals of Photonics, Second Edition is a self-contained and up-to-date introductory-level textbook that thoroughly surveys this rapidly expanding area of engineering and applied physics. Featuring a logical blend of theory and applications, coverage includes detailed accounts of the primary theories of light, including ray optics, wave optics, electromagnetic optics, and photon optics, as well as the interaction of photons and atoms, and semiconductor optics. Presented at increasing levels of complexity, preliminary sections build toward more advan

  3. Taxing Junk Food to Counter Obesity

    Science.gov (United States)

    Franck, Caroline; Grandi, Sonia M.

    2013-01-01

    We examined the advantages and disadvantages of implementing a junk food tax as an intervention to counter increasing obesity in North America. Small excise taxes are likely to yield substantial revenue but are unlikely to affect obesity rates. High excise taxes are likely to have a direct impact on weight in at-risk populations but are less likely to be politically palatable or sustainable. Ultimately, the effectiveness of earmarked health programs and subsidies is likely to be a key determinant of tax success in the fight against obesity. PMID:24028245

  4. Rate dependent image distortions in proportional counters

    International Nuclear Information System (INIS)

    Trow, M.W.; Bento, A.C.; Smith, A.

    1994-01-01

    The positional linearity of imaging proportional counters is affected by the intensity distribution of the incident radiation. A mechanism for this effect is described, in which drifting positive ions in the gas produce a distorting electric field which perturbs the trajectories of the primary electrons. In certain cases, the phenomenon causes an apparent improvement of the position resolution. We demonstrate the effect in a detector filled with a xenon-argon-CO 2 mixture. The images obtained are compared with the results of a simulation. If quantitative predictions for a particular detector are required, accurate values of the absolute detector gain, ion mobility and electron drift velocity are needed. ((orig.))

  5. Industrial espionage and technical surveillance counter measurers

    CERN Document Server

    Androulidakis, Iosif

    2016-01-01

    This book examines technical aspects of industrial espionage and its impact in modern companies, organizations, and individuals while emphasizing the importance of intellectual property in the information era. The authors discuss the problem itself and then provide statistics and real world cases. The main contribution provides a detailed discussion of the actual equipment, tools and techniques concerning technical surveillance in the framework of espionage. Moreover, they present the best practices and methods of detection (technical surveillance counter measures) as well as means of intellectual property protection.

  6. Taxing junk food to counter obesity.

    Science.gov (United States)

    Franck, Caroline; Grandi, Sonia M; Eisenberg, Mark J

    2013-11-01

    We examined the advantages and disadvantages of implementing a junk food tax as an intervention to counter increasing obesity in North America. Small excise taxes are likely to yield substantial revenue but are unlikely to affect obesity rates. High excise taxes are likely to have a direct impact on weight in at-risk populations but are less likely to be politically palatable or sustainable. Ultimately, the effectiveness of earmarked health programs and subsidies is likely to be a key determinant of tax success in the fight against obesity.

  7. Cerenkov counter for the experiment NA3

    CERN Multimedia

    1978-01-01

    The program of the NA3 experiment included the study of hadronic interactions with a large transverse momentum pT, thus the inclusion in the set-up of three gas threshold Cerenkov counters of large acceptance. The photo shows the downstream part of the second Cerenkov (located at the output of the magnet). The yellow membrane is a temporary protection for the optics (shown in photo 7810540X) to be taken away when fixing this part to the gas tank (entering the magnet and not shown). The photomultipliers all around are heavily shielded.

  8. Use of parallel counters for triggering

    International Nuclear Information System (INIS)

    Nikityuk, N.M.

    1991-01-01

    Results of investigation of using parallel counters, majority coincidence schemes, parallel compressors for triggering in multichannel high energy spectrometers are described. Concrete examples of methods of constructing fast and economic new devices used to determine multiplicity hits t>900 registered in a hodoscopic plane and a pixel detector are given. For this purpose the author uses the syndrome coding method and cellular arrays. In addition, an effective coding matrix has been created which can be used for light signal coding. For example, such signals are supplied from scintillators to photomultipliers. 23 refs.; 21 figs

  9. Tomography of photon-added and photon-subtracted states

    NARCIS (Netherlands)

    Bazrafkan, MR; Man'ko, [No Value

    The purpose of this paper is to introduce symplectic and optical tomograms of photon-added and photon-subtracted quantum states. Explicit relations for the tomograms of photon-added and photon-subtracted squeezed coherent states and squeezed number states are obtained. Generating functions for the

  10. Hadronic photon-photon interactions at high energies

    International Nuclear Information System (INIS)

    Engel, R.; Siegen Univ.; Ranft, J.

    1996-01-01

    Photon-photon collisions are investigated in the framework of the two-component Dual Parton Model. The model contains contributions from direct, resolved soft and resolved hard interactions. All free parameters of the model are determined in fits to hadron-hadron and photon-hadron cross section data. The model is shown to agree well to hadron production data from hadron-hadron and photon-hadron collisions. The multiparticle production in hadron-hadron, photon-hadron and photon-photon collisions as predicted by the model is compared. Strong differences are only found as function of the transverse momentum variable. (author)

  11. Microwave background constraints on mixing of photons with hidden photons

    International Nuclear Information System (INIS)

    Mirizzi, Alessandro; Redondo, Javier; Sigl, Guenter

    2008-12-01

    Various extensions of the Standard Model predict the existence of hidden photons kinetically mixing with the ordinary photon. This mixing leads to oscillations between photons and hidden photons, analogous to the observed oscillations between different neutrino flavors. In this context, we derive new bounds on the photon-hidden photon mixing parameters using the high precision cosmic microwave background spectral data collected by the Far Infrared Absolute Spectrophotometer instrument on board of the Cosmic Background Explorer. Requiring the distortions of the CMB induced by the photon-hidden photon mixing to be smaller than experimental upper limits, this leads to a bound on the mixing angle χ 0 -7 - 10 -5 for hidden photon masses between 10 -14 eV and 10 -7 eV. This low-mass and low-mixing region of the hidden photon parameter space was previously unconstrained. (orig.)

  12. Microwave background constraints on mixing of photons with hidden photons

    Energy Technology Data Exchange (ETDEWEB)

    Mirizzi, Alessandro [Max-Planck-Institut fuer Physik, Muenchen (Germany); Redondo, Javier [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Sigl, Guenter [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

    2008-12-15

    Various extensions of the Standard Model predict the existence of hidden photons kinetically mixing with the ordinary photon. This mixing leads to oscillations between photons and hidden photons, analogous to the observed oscillations between different neutrino flavors. In this context, we derive new bounds on the photon-hidden photon mixing parameters using the high precision cosmic microwave background spectral data collected by the Far Infrared Absolute Spectrophotometer instrument on board of the Cosmic Background Explorer. Requiring the distortions of the CMB induced by the photon-hidden photon mixing to be smaller than experimental upper limits, this leads to a bound on the mixing angle {chi}{sub 0}

  13. Microwave photonics shines

    Science.gov (United States)

    Won, Rachel

    2011-12-01

    The combination of microwave photonics and optics has advanced many applications in defence, wireless communications, imaging and network infrastructure. Rachel Won talks to Jianping Yao from the University of Ottawa in Canada about the importance of this growing field.

  14. Photon induced reactions

    International Nuclear Information System (INIS)

    Mecking, B.A.

    1982-04-01

    Various aspects of medium energy nuclear reactions induced by real photons are reviewed. Special emphasis is put on high accuracy experiments that will become possible with the next generation of electron accelerators. (orig.)

  15. Photons and magnetization

    Czech Academy of Sciences Publication Activity Database

    Pile, P.; Němec, P.; Jungwirth, Tomáš

    2013-01-01

    Roč. 7, č. 6 (2013), s. 500 ISSN 1749-4885 Institutional support: RVO:68378271 Keywords : spintronics * photonics * magneto-optics Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 29.958, year: 2013

  16. Photonic Crystal Nanocavity Arrays

    National Research Council Canada - National Science Library

    Altug, Hatice; Vuckovic, Jelena

    2006-01-01

    We recently proposed two-dimensional coupled photonic crystal nanocavity arrays as a route to achieve a slow-group velocity of light in all crystal directions, thereby enabling numerous applications...

  17. Photonic Crystal Fibers

    National Research Council Canada - National Science Library

    Kristiansen, Rene E

    2005-01-01

    This report results from a contract tasking Crystal Fibre A/S as follows: Crystal Fibre will conduct research and development of large mode area, dual clad multi-core Yb-doped photonic crystal fiber...

  18. Principles of photonics

    CERN Document Server

    Liu, Jia-Ming

    2016-01-01

    With this self-contained and comprehensive text, students will gain a detailed understanding of the fundamental concepts and major principles of photonics. Assuming only a basic background in optics, readers are guided through key topics such as the nature of optical fields, the properties of optical materials, and the principles of major photonic functions regarding the generation, propagation, coupling, interference, amplification, modulation, and detection of optical waves or signals. Numerous examples and problems are provided throughout to enhance understanding, and a solutions manual containing detailed solutions and explanations is available online for instructors. This is the ideal resource for electrical engineering and physics undergraduates taking introductory, single-semester or single-quarter courses in photonics, providing them with the knowledge and skills needed to progress to more advanced courses on photonic devices, systems and applications.

  19. Photonic Quantum Information Processing

    International Nuclear Information System (INIS)

    Walther, P.

    2012-01-01

    The advantage of the photon's mobility makes optical quantum system ideally suited for delegated quantum computation. I will present results for the realization for a measurement-based quantum network in a client-server environment, where quantum information is securely communicated and computed. Related to measurement-based quantum computing I will discuss a recent experiment showing that quantum discord can be used as resource for the remote state preparation, which might shine new light on the requirements for quantum-enhanced information processing. Finally, I will briefly review recent photonic quantum simulation experiments of four frustrated Heisenberg-interactions spins and present an outlook of feasible simulation experiments with more complex interactions or random walk structures. As outlook I will discuss the current status of new quantum technology for improving the scalability of photonic quantum systems by using superconducting single-photon detectors and tailored light-matter interactions. (author)

  20. Investigations of X-ray response of single wire anode Ar-N2 flow type gas scintillation proportional counters

    International Nuclear Information System (INIS)

    Garg, S.P.; Sharma, R.C.

    1984-01-01

    The X-ray response of single wire anode gas scintillation proportional counters of two different geometries operated with argon+nitrogen gases in continuous flow has been investigated with wire anodes of diameters 25 μm to 1.7 mm. An energy resolution of 19% is obtained for 5.9 keV X-rays entering the counter perpendicular to the anode in pill-box geometry with 25 μm diameter anode. With cylindrical geometry counters energy obtained at 5.9 keV are 18%, 24% and 33% for 50 μm, 0.5 mm and 1.7 mm diameter anodes respectively. An analysis of the observed resolution shows that the contribution from photon counting statistics to the relative variance of scintillation pulses even for X-rays in Ar-N 2 single wire anode gas scintillation proportional counters is small and is not a limiting factor. The energy resolution with thicker anodes, where the contribution from the variance of the charge multiplication factor also has been minimised, is found to deteriorate mainly by the interaction in the scintillation production region. Comments are made on the possibility of improvement in energy resolution by suppression of pulses due to such interactions with the help of the pulse risetime discrimination technique. (orig.)

  1. Governmentality, Counter-conduct and Prefigurative Demonstrations

    DEFF Research Database (Denmark)

    McIlvenny, Paul

    2016-01-01

    This chapter attends to the micro-ethnographic detail of actual practices, procedures and technologies – the techne – of governance, especially those practices that manifest as what Foucault called ‘counter-conducts’. The interactional and categorial practices of a prefigurative protest demonstra......This chapter attends to the micro-ethnographic detail of actual practices, procedures and technologies – the techne – of governance, especially those practices that manifest as what Foucault called ‘counter-conducts’. The interactional and categorial practices of a prefigurative protest...... demonstration are examined using video recordings that were made of a theatrical protest event called “United Nathans weapons inspections” in February 2003. The chapter draws upon Mitchell Dean’s analytics of government and Carl Death’s analytics of protest. A first step in an analytics of protest is to uncover...... how fields of visibility, forms of knowledge, technologies and apparatuses, and subjectivities and identities are negotiated and accomplished collaboratively. Specific tools and methods that are well suited to investigating the situated practices, procedures and technologies of governmentality...

  2. Possible nonvanishing mass of photon

    International Nuclear Information System (INIS)

    Nakazato, Hiromichi; Namiki, Mikio; Yamanaka, Yoshiya; Yokoyama, Kan-ichi.

    1985-05-01

    From phenomenological and field-theoretical considerations on photon mass, we first show that photon is not limitted to being massless at the present stage. Next we illustrate a possibility of formulating a local field theory for massive photons coupled with nonconserved currents, while we cannot do for massless photons. (author)

  3. The photon collider at TESLA

    Czech Academy of Sciences Publication Activity Database

    Badelek, B.; Bloechinger, C.; Blümlein, J.; Boos, E.; Brinkman, R.; Burkhardt, H.; Bussey, P.; Carimalo, C.; Chýla, Jiří; Ciftci, A.K.

    2004-01-01

    Roč. 19, č. 30 (2004), s. 5097-5186 ISSN 0217-751X Institutional research plan: CEZ:AV0Z1010920 Keywords : photon collider * linear collider * gamma-gamma * photon-photon * photon electron * Compton scattering Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 1.054, year: 2004

  4. ALICE photon spectrometer crystals

    CERN Multimedia

    Maximilien Brice

    2006-01-01

    Members of the mechanical assembly team insert the last few crystals into the first module of ALICE's photon spectrometer. These crystals are made from lead-tungstate, a crystal as clear as glass but with nearly four times the density. When a high-energy particle passes through one of these crystals it will scintillate, emitting a flash of light allowing the energy of photons, electrons and positrons to be measured.

  5. Photon structure function

    International Nuclear Information System (INIS)

    Bardeen, W.A.

    1980-11-01

    Theoretical understanding of the photon structure function is reviewed. As an illustration of the pointlike component, the parton model is briefly discussed. However, the systematic study of the photon structure function is presented through the framework of the operator product expansion. Perturbative QCD is used as the theoretical basis for the calculation of leading contributions to the operator product expansion. The influence of higher order QCD effects on these results is discussed. Recent results for the polarized structure functions are discussed

  6. Hard processes in photon-photon interactions

    International Nuclear Information System (INIS)

    Duchovni, E.

    1985-03-01

    In this thesis, the existence of hard component in two-photon collisions is investigated. Due to the relative simplicity of the photon, such processes can be exactly calculated in QCD. Untagged (low Q 2 ) two-photon events are used. This leads to relatively high statistics, but to severe background problem due mainly to e + e - annihilation. The background contamination is reduced to a tolerable level using a special set of cuts. Moreover, the remaining contamination is shown to be calculable with a small systematic error. A large number of events of the hard ''γγ'' type is found. An attempt to explain these events using the simplest QCD diagram (the Born term) is done. This process is found to be capable of explaining only a 1/4 of the data. Other options like the constituent intercharge model, integer charged quarks, and higher order diagrams are therefore also discussed. The large cross-section for the production of ρ 0 ρ 0 pairs in ''γγ'' collisions has not been understood yet. Inorder to look at closely related processes, a search for φρ 0 and φφ was initiated. The cross-section for θπ + π - was found to be sizeable. Only upper limits for the production of φρ 0 and φφ are obtained

  7. Post-PRK corneal scatter measurements with a scanning confocal slit photon counter

    Science.gov (United States)

    Taboada, John; Gaines, David; Perez, Mary A.; Waller, Steve G.; Ivan, Douglas J.; Baldwin, J. Bruce; LoRusso, Frank; Tutt, Ronald C.; Perez, Jose; Tredici, Thomas; Johnson, Dan A.

    2000-06-01

    Increased corneal light scatter or 'haze' has been associated with excimer laser photorefractive surgery of the cornea. The increased scatter can affect visual performance; however, topical steroid treatment post surgery substantially reduces the post PRK scatter. For the treatment and monitoring of the scattering characteristics of the cornea, various methods have been developed to objectively measure the magnitude of the scatter. These methods generally can measure scatter associated with clinically observable levels of haze. For patients with moderate to low PRK corrections receiving steroid treatment, measurement becomes fairly difficult as the haze clinical rating is non observable. The goal of this development was to realize an objective, non-invasive physical measurement that could produce a significant reading for any level including the background present in a normal cornea. As back-scatter is the only readily accessible observable, the instrument is based on this measurement. To achieve this end required the use of a confocal method to bias out the background light that would normally confound conventional methods. A number of subjects with nominal refractive errors in an Air Force study have undergone PRK surgery. A measurable increase in corneal scatter has been observed in these subjects whereas clinical ratings of the haze were noted as level zero. Other favorable aspects of this back-scatter based instrument include an optical capability to perform what is equivalent to an optical A-scan of the anterior chamber. Lens scatter can also be measured.

  8. First in situ TOF-PET study using digital photon counters for proton range verification

    NARCIS (Netherlands)

    Cambraia Lopes Ferreira da Silva, P.; Bauer, J.; Salomon, A.; Rinaldi, I; Tabacchini, V.; Tessonnier, T.; Crespo, P; Parodi, K; Schaart, D.R.

    2016-01-01

    Positron emission tomography (PET) is the imaging modality most extensively tested for treatment monitoring in particle therapy. Optimal use of PET in proton therapy requires in situ acquisition of the relatively strong 15O signal due to its relatively short half-life (∼2 min) and high

  9. Single-photon imaging

    International Nuclear Information System (INIS)

    Seitz, Peter; Theuwissen, Albert J.P.

    2011-01-01

    The acquisition and interpretation of images is a central capability in almost all scientific and technological domains. In particular, the acquisition of electromagnetic radiation, in the form of visible light, UV, infrared, X-ray, etc. is of enormous practical importance. The ultimate sensitivity in electronic imaging is the detection of individual photons. With this book, the first comprehensive review of all aspects of single-photon electronic imaging has been created. Topics include theoretical basics, semiconductor fabrication, single-photon detection principles, imager design and applications of different spectral domains. Today, the solid-state fabrication capabilities for several types of image sensors has advanced to a point, where uncooled single-photon electronic imaging will soon become a consumer product. This book is giving a specialist's view from different domains to the forthcoming ''single-photon imaging'' revolution. The various aspects of single-photon imaging are treated by internationally renowned, leading scientists and technologists who have all pioneered their respective fields. (orig.)

  10. Reduction of degraded events in miniaturized proportional counters

    Energy Technology Data Exchange (ETDEWEB)

    Plaga, R.; Kirsten, T. (Max Planck Inst. fuer Kernphysik, Heidelberg (Germany))

    1991-11-15

    A method to reduce the number of degraded events in miniaturized proportional counters is described. A shaping of the outer cathode leads to a more uniform gas gain along the counter axis. The method is useful in situations in which the total number of decay events is very low. The effects leading to degraded events are studied theoretically and experimentally. The usefulness of the method is demonstrated by using it for the proportional counter of the GALLEX solar neutrino experiment. (orig.).

  11. Construction and calibration studies of the SAPHIR scintillation counters

    International Nuclear Information System (INIS)

    Kostrewa, D.

    1988-03-01

    For the scintillation counter system of the SAPHIR detector at the stretcher ring ELSA in Bonn 50 time of flight counters and 12 trigger counters have been built. Each of them has two photomultipliers, one at each side. A laser calibration system with a pulsed nitrogen laser as central light source to monitor these photomultipliers has been optimized. It was used to adjust the photomultipliers and to test their long and short time instabilities. (orig.)

  12. Criticism and Counter-Criticism of Public Management: Strategy Models

    OpenAIRE

    Luis C. Ortigueira

    2007-01-01

    Critical control is very important in scientific management. This paper presents models of critical and counter-critical public-management strategies, focusing on the types of criticism and counter-criticism manifested in parliamentary political debates. The paper includes: (i) a normative model showing how rational criticism can be carried out; (ii) a normative model for oral critical intervention; and (iii) a general motivational strategy model for criticisms and counter-criticisms. The pap...

  13. Electronics system for transuranic waste assays using a photon interrogation technique

    International Nuclear Information System (INIS)

    Johnson, L.O.; Lawrence, R.S.

    1979-12-01

    This report documents the development of electronics for a neutron detection system used in experiments to demonstrate the feasibility of a photon interrogation technique for transuranic (TRU) waste assays. The system consists of the neutron detection and signal conditioning circuits, variable time-gate generators, and a data acquisition system. The data acquisition system is configured using commercially available scalers, timers, teletype, and control components. The remainder of the system, with the exception of the neutron detectors, uses components designed in-house. The neutron detection system consists of 3 He proportional counters installed in a polyethylene moderator assembly. The counters are direct-coupled to a high-count-rate, current-sensitive preamplifier. The preamplifier and an additional two-stage amplifier are also installed in the moderator assembly. Signal conditioning includes baseline restoration and fast discrimination. A variable time-gate generator with logic gates allows for separation of prompt and delayed neutron counts, and generation of prompt and delayed deadtimes. The 3 He proportional counters will detect not only the neutrons from the TRU waste sample, but also the high-energy photons used to induce fission in the sample. The burst of photons (gamma flash) tends to overload and paralyze the electronics. This system has been designed to recover from a worst-case gamma flash overload within 10 microseconds. The system has met all the requirements generated for the photon interrogation experiments

  14. Hardware support for software controlled fast reconfiguration of performance counters

    Science.gov (United States)

    Salapura, Valentina; Wisniewski, Robert W.

    2013-06-18

    Hardware support for software controlled reconfiguration of performance counters may include a plurality of performance counters collecting one or more counts of one or more selected activities. A storage element stores data value representing a time interval, and a timer element reads the data value and detects expiration of the time interval based on the data value and generates a signal. A plurality of configuration registers stores a set of performance counter configurations. A state machine receives the signal and selects a configuration register from the plurality of configuration registers for reconfiguring the one or more performance counters.

  15. Neutron dosimetry using proportional counters with tissue equivalent walls

    International Nuclear Information System (INIS)

    Kerviller, H. de

    1965-01-01

    The author reminds the calculation method of the neutron absorbed dose in a material and deduce of it the conditions what this material have to fill to be equivalent to biological tissues. Various proportional counters are mode with walls in new tissue equivalent material and filled with various gases. The multiplication factor and neutron energy response of these counters are investigated and compared with those obtained with ethylene lined polyethylene counters. The conditions of working of such proportional counters for neutron dosimetry in energy range 10 -2 to 15 MeV are specified. (author) [fr

  16. Cosmic Ray Background Analysis For A Cargo Container Counter

    International Nuclear Information System (INIS)

    Ensslin, Norbert; Geist, W.H.; Lestone, J.P.; Mayo, D.R.; Menlove, Howard O.

    2001-01-01

    We have developed a new model for calculating the expected yield of cosmic-ray spallation neutrons in a Cargo Container Counter, and we have benchmarked the model against measurements made with several existing large neutron counters. We also developed two versions of a new measurement uncertainty prediction code based on Microsoft Excel spreadsheets. The codes calculate the minimum detectability limit for the Cargo Container Counter for either neutron singles or doubles counting, and also propagate the uncertainties associated with efficiency normalization flux monitors and cosmic ray flux monitors. This paper will describe the physics basis for this analysis, and the results obtained for several different counter designs.

  17. Experimental demonstration of robust entanglement distribution over reciprocal noisy channels assisted by a counter-propagating classical reference light.

    Science.gov (United States)

    Ikuta, Rikizo; Nozaki, Shota; Yamamoto, Takashi; Koashi, Masato; Imoto, Nobuyuki

    2017-07-06

    Embedding a quantum state in a decoherence-free subspace (DFS) formed by multiple photons is one of the promising methods for robust entanglement distribution of photonic states over collective noisy channels. In practice, however, such a scheme suffers from a low efficiency proportional to transmittance of the channel to the power of the number of photons forming the DFS. The use of a counter-propagating coherent pulse can improve the efficiency to scale linearly in the channel transmission, but it achieves only protection against phase noises. Recently, it was theoretically proposed [Phys. Rev. A 87, 052325(2013)] that the protection against bit-flip noises can also be achieved if the channel has a reciprocal property. Here we experimentally demonstrate the proposed scheme to distribute polarization-entangled photon pairs against a general collective noise including the bit flip noise and the phase noise. We observed an efficient sharing rate scaling while keeping a high quality of the distributed entangled state. Furthermore, we show that the method is applicable not only to the entanglement distribution but also to the transmission of arbitrary polarization states of a single photon.

  18. Development of a 144-channel Hybrid Avalanche Photo-Detector for Belle II ring-imaging Cherenkov counter with an aerogel radiator

    Energy Technology Data Exchange (ETDEWEB)

    Nishida, S., E-mail: shohei.nishida@kek.jp [High Energy Accelerator Research Organization (KEK), Tsukuba (Japan); Adachi, I. [High Energy Accelerator Research Organization (KEK), Tsukuba (Japan); Hamada, N. [Toho University, Funabashi (Japan); Hara, K. [High Energy Accelerator Research Organization (KEK), Tsukuba (Japan); Iijima, T. [Nagoya University, Nagoya (Japan); Iwata, S.; Kakuno, H. [Tokyo Metropolitan University, Hachioji (Japan); Kawai, H. [Chiba University, Chiba (Japan); Korpar, S.; Krizan, P. [Jozef Stefan Institute, Ljubljana (Slovenia); Ogawa, S. [Toho University, Funabashi (Japan); Pestotnik, R.; Ŝantelj, L.; Seljak, A. [Jozef Stefan Institute, Ljubljana (Slovenia); Sumiyoshi, T. [Tokyo Metropolitan University, Hachioji (Japan); Tabata, M. [Chiba University, Chiba (Japan); Tahirovic, E. [Jozef Stefan Institute, Ljubljana (Slovenia); Yoshida, K. [Tokyo Metropolitan University, Hachioji (Japan); Yusa, Y. [Niigata University, Niigata (Japan)

    2015-07-01

    The Belle II detector, a follow up of the very successful Belle experiment, is under construction at the SuperKEKB electron–positron collider at KEK in Japan. For the PID system in the forward region of the spectrometer, a proximity-focusing ring-imaging Cherenkov counter with an aerogel radiator is being developed. For the position sensitive photon sensor, a 144-channel Hybrid Avalanche Photo-Detector has been developed with Hamamatsu Photonics K.K. In this report, we describe the specification of the Hybrid Avalanche Photo-Detector and the status of the mass production.

  19. Multi-photon absorption limits to heralded single photon sources

    Science.gov (United States)

    Husko, Chad A.; Clark, Alex S.; Collins, Matthew J.; De Rossi, Alfredo; Combrié, Sylvain; Lehoucq, Gaëlle; Rey, Isabella H.; Krauss, Thomas F.; Xiong, Chunle; Eggleton, Benjamin J.

    2013-01-01

    Single photons are of paramount importance to future quantum technologies, including quantum communication and computation. Nonlinear photonic devices using parametric processes offer a straightforward route to generating photons, however additional nonlinear processes may come into play and interfere with these sources. Here we analyse spontaneous four-wave mixing (SFWM) sources in the presence of multi-photon processes. We conduct experiments in silicon and gallium indium phosphide photonic crystal waveguides which display inherently different nonlinear absorption processes, namely two-photon (TPA) and three-photon absorption (ThPA), respectively. We develop a novel model capturing these diverse effects which is in excellent quantitative agreement with measurements of brightness, coincidence-to-accidental ratio (CAR) and second-order correlation function g(2)(0), showing that TPA imposes an intrinsic limit on heralded single photon sources. We build on these observations to devise a new metric, the quantum utility (QMU), enabling further optimisation of single photon sources. PMID:24186400

  20. Non-Poissonian photon statistics from macroscopic photon cutting materials.

    Science.gov (United States)

    de Jong, Mathijs; Meijerink, Andries; Rabouw, Freddy T

    2017-05-24

    In optical materials energy is usually extracted only from the lowest excited state, resulting in fundamental energy-efficiency limits such as the Shockley-Queisser limit for single-junction solar cells. Photon-cutting materials provide a way around such limits by absorbing high-energy photons and 'cutting' them into multiple low-energy excitations that can subsequently be extracted. The occurrence of photon cutting or quantum cutting has been demonstrated in a variety of materials, including semiconductor quantum dots, lanthanides and organic dyes. Here we show that photon cutting results in bunched photon emission on the timescale of the excited-state lifetime, even when observing a macroscopic number of optical centres. Our theoretical derivation matches well with experimental data on NaLaF 4 :Pr 3+ , a material that can cut deep-ultraviolet photons into two visible photons. This signature of photon cutting can be used to identify and characterize new photon-cutting materials unambiguously.

  1. Fiber-Optic Monitoring System of Particle Counters

    Directory of Open Access Journals (Sweden)

    A. A. Titov

    2016-01-01

    Full Text Available The article considers development of a fiber-optic system to monitor the counters of particles. Presently, optical counters of particles, which are often arranged at considerable distance from each other, are used to study the saltation phenomenon. For monitoring the counters, can be used electric communication lines.However, it complicates and raises the price of system Therefore, we offered a fiber-optic system and the counter of particles, free from these shortcomings. The difference between the offered counter of particles and the known one is that the input of radiation to the counter and the output of radiation scattering on particles are made by the optical fibers, and direct radiation is entered the optical fiber rather than is delayed by a light trap and can be used for lighting the other counters thereby allowing to use their connection in series.The work involved a choice of the quartz multimode optical fiber for communication, defining the optical fiber and lenses parameters of the counter of particles, and a selection of the radiation source and the photo-detector.Using the theory of light diffraction on a particle, a measuring range of the particle sizes has been determined. The system speed has been estimated, and it has been shown that a range of communication can reach 200km.It should be noted that modulation noise of counters of particles connected in series have the impact on the useful signal. To assess the extent of this influence we have developed a calculation procedure to illustrate that with ten counters connected in series this influence on the signal-to-noise ratio will be insignificant.Thus, it has been shown that the offered fiber-optic system can be used for monitoring the counters of particles across the desertified territories. 

  2. Mass transfer in counter current flows

    Energy Technology Data Exchange (ETDEWEB)

    Doichinova, Maria D.; Popova, Petya G.; Boyadjiev, Christo B. [Bulgarian Academy of Science, Institute of Chemical Engineering, Sofia (Bulgaria)

    2011-07-01

    A theoretical analysis of gas-liquid counter-current flow in laminar boundary layers with flat phase boundary based on similarity variables method has been done. The obtained numerical results for the energy dissipation, mass transfer rate and their ratio are compared with analogous results for concurrent flows. A diffusion type of model is proposed for modeling of the mass transfer with chemical reaction in the column apparatuses in the cases of circulation zones. The presence of rising and descending flows (the change of the velocity direction) leads to using three coordinate systems. An iterative algorithm for the concentration distribution calculation is proposed. The influence of the zones breadths on the mass transfer efficiency in the column is investigated. Key words: efficiency, mass transfer, velocity distribution, column apparatuses, circulation zones.

  3. Absolute calibration of TFTR helium proportional counters

    International Nuclear Information System (INIS)

    Strachan, J.D.; Diesso, M.; Jassby, D.; Johnson, L.; McCauley, S.; Munsat, T.; Roquemore, A.L.; Loughlin, M.

    1995-06-01

    The TFTR helium proportional counters are located in the central five (5) channels of the TFTR multichannel neutron collimator. These detectors were absolutely calibrated using a 14 MeV neutron generator positioned at the horizontal midplane of the TFTR vacuum vessel. The neutron generator position was scanned in centimeter steps to determine the collimator aperture width to 14 MeV neutrons and the absolute sensitivity of each channel. Neutron profiles were measured for TFTR plasmas with time resolution between 5 msec and 50 msec depending upon count rates. The He detectors were used to measure the burnup of 1 MeV tritons in deuterium plasmas, the transport of tritium in trace tritium experiments, and the residual tritium levels in plasmas following 50:50 DT experiments

  4. CWRU multiwire proportional counter readout system

    International Nuclear Information System (INIS)

    Bevington, P.R.; Leskovec, R.A.

    1977-01-01

    An electronic system is described which translates pulses from individual wires of multiwire proportional counters into binary addresses indicating the location of the wires in the chambers. The system combines a fast (<100 ns) serial scan of an event buffer with parallel encoding to provide fast transfer of addresses (250 ns per hit). The buffer has provision for disabling the input less than 40 ns after detection of an event to suppress recording of multiple hits caused by individual events. The encoder can digitize the address of every hit encountered or just the first addresses of contiguous hits. The system includes a coincidence trigger for determining whether timing criteria have been satisfied between chambers and with external devices. Events which do not meet the coincidence criteria are typically reset within 400 ns. The addresses are transferred to a computer interface through CAMAC modules. Multiple buffering permits further data acquisition during CAMAC transfer cycles. (Auth.)

  5. Fabrication of preamplifier for proportional counter

    International Nuclear Information System (INIS)

    Lotfi, Y.; Yazdanpanah, M.; Talebi, B.; Mohammadi, A.; Etaati, Gh.

    2002-01-01

    We have tried to describe techniques of preamplifier fabrication for proportional counter. At first electronic circuit of preamplifier has been analyzed by means of Or cad 9.1. Then we assembled the circuit. Thereafter essential and standard parameters of preamplifier has been measured and compared with foreign made one, according to IEEE standard method. (IEEE Std 301-1988) Specification for our preamplifier is: 1. Rise time of output plus: 25 nsec. 2. Fall time of output pulse: 50μ sec. 3. Charge sensitive: 46.3 mV/pc. 4. Average noise: 500 ion pair (rms) 5. Count R ate L imit: 9.14*10 10 Count/sec. 6. Resolution: %1.3 7. Spectrum of Bf3 detector to 300μ Ci Am-Be source for this preamplifier is the same as foreign one. On the Whole comparison of this preamplifier with the foreign one shows that their parameters similarity is about %95

  6. Efficiency simulation of long neutron counter

    International Nuclear Information System (INIS)

    Hu Qingyuan; Li Bojun; Zhang De; Guo Hongsheng; Wang Dong; Yang Gaozhao; Si Fenni; Liu Jian

    2008-01-01

    In order to achieve the high efficiency and uniform sensitivity for neutrons with widely different energies, the efficiency of long boron trifluoride proportional counter imbedded in polyethylene moderator was simulated by MCNP code. The result shows that detective efficiency would increase with increasing moderator radius and response curve at higher energy would be ameliorated through adjusting the thickness of front moderator. Also we calculated the relative efficiencies for different energy of a detector whose efficiencies were calibrated on an accelerator. The simulated efficiency for D-D neutrons (2.4 MeV) is 75% of the efficiency for D-T neutrons (14.1 MeV), which is approximately agreed with experimental data, 61%. The validity of the simulated model was proved by the consistent results between calculation and experiment data. (authors)

  7. Fast-neutron coincidence-counter manual

    International Nuclear Information System (INIS)

    Ensslin, N.; Atwell, T.L.; Lee, D.M.; Erkkila, B.; Marshall, R.S.; Morgan, A.; Shonrock, C.; Tippens, B.; Van Lyssel, T.

    1982-03-01

    The fast neutron counter (FNC) described in this report is a computer-based assay system employing fast-pulse counting instrumentation. It is installed below a glove box in the metal electrorefining area of the Los Alamos National Laboratory Plutonium Processing Facility. The instrument was designed to assay plutonium salts and residues from this process and to verify the mass of electrorefined metal. Los Alamos National Laboratory Groups Q-1, Q-3, and CMB-11 carried out a joint test and evaluation plan of this instrument between May 1978 and May 1979. The results of that evaluation, a description of the FNC, and operating instructions for further use are given in this report

  8. The multimodal argumentation of persuasive counter discourses

    DEFF Research Database (Denmark)

    Maier, Carmen Daniela

    The continuous interest in and concern with business communication can be detected in the way critical aspects of this kind of communication are represented and debated in a wide range of discourses in a wide range of contexts. Drawing upon a social semiotic perspective, this paper explores...... the persuasive counter discourse of Media Bites videos: http://griid.org/category/media-bites/. The videos are a part of GRIID organization’s efforts directed at revealing misleading communicative strategies employed in various business contexts. In these instructive videos, the viewers are made familiar...... the misleading strategies employed. The viewers are also instructed where else they can find information about these strategies and the consequences of misleading advertising discourse. The argumentation framework of the Media Bites videos is also persuasively articulated for engaging the viewers as active...

  9. CAMAC differential pulse discriminator-counter

    International Nuclear Information System (INIS)

    Tselikov, N.V.

    1987-01-01

    Differential pulse discriminator-counter for Moessbauer spectrometer is described. Input pulse setting into the channel is performed according to the following algorithm: the pulse is transmitted to the channel depending on the fact whether the preceding pulse has got to the discrimination window or not. The circuit does not contain delay lines, taking into account the delay of a signal from the upper level discriminator in relation to the lower level discriminator signal, which is connected with input pulse rise finite time, which in turn allows one to reduce the discriminator dead time up to the operation time of threshold circuits. The pulse counting rate is 150 MHz, input signal amplitude is ±3 V, dead time is 6 ns, delay time from input to output is 14 ns. The unit is made in CAMAC system

  10. Quality measurement by proportional counter with B

    International Nuclear Information System (INIS)

    Onizuka, Yoshihiko; Endo, Satoru; Tanaka, Kenichi

    2005-01-01

    The dosimetry of air and the tissue-equivalent phantom made of acryl are carried out by the tissue-equivalent proportional counter (TEPC) and TEPC with wall contained B, and both results were compared. The changes of quality with distance from the beam center are determined by the frequency mean renewal energy y F (y)and the dose mean renewal energy y D (y) as indicators of quality. Both y F (y)and y D (y) of tissue-equivalent phantom are larger than air, but very large change was not observed in all distance. The dose rate is determined by y D (y), the number of events and measurement time. Change of dose rate was larger than the change of quality. The maximum value of dose rate depended on γray and neutron beam showed at the point 2 cm away from the center. (S.Y.)

  11. China's Cyber Initiatives Counter International Pressure

    Directory of Open Access Journals (Sweden)

    Emilio Iasiello

    2017-03-01

    Full Text Available Prior to its historic 2015 “no hack” pact for commercial advantage with the United States, Beijing has been engaged drafting and passing legislation, most with specific cyber components, to enhance its security posture while protecting its economic interests. This approach is in stark contrast to United States efforts that have demonstrated a focus on “acting globally, thinking locally” philosophy wherein most of its cyber efforts have been outwardly facing and are distinct from other security considerations. This paper suggests that by strengthening its domestic front with a legal framework, Beijing is preparing itself to counter any foreign initiative contrary to Beijing’s plans (e.g., cyber norms of behavior, cyber sanctions, etc. by being able to exert legal measures against foreign interests in country, thereby preserving its cyber sovereignty.

  12. CMOS-compatible photonic devices for single-photon generation

    Directory of Open Access Journals (Sweden)

    Xiong Chunle

    2016-09-01

    Full Text Available Sources of single photons are one of the key building blocks for quantum photonic technologies such as quantum secure communication and powerful quantum computing. To bring the proof-of-principle demonstration of these technologies from the laboratory to the real world, complementary metal–oxide–semiconductor (CMOS-compatible photonic chips are highly desirable for photon generation, manipulation, processing and even detection because of their compactness, scalability, robustness, and the potential for integration with electronics. In this paper, we review the development of photonic devices made from materials (e.g., silicon and processes that are compatible with CMOS fabrication facilities for the generation of single photons.

  13. Counter current decantation washing of HLW sludge

    International Nuclear Information System (INIS)

    Brooke, J.N.; Peterson, R.A.

    1997-01-01

    The Savannah River Site (SRS) has 51 High Level Waste (HLW) tanks with typical dimensions 25.9 meters (85 feet) diameter and 10 meters (33 feet) high. Nearly 114 million liters (30 M gallons) of HLW waste is stored in these tanks in the form of insoluble solids called sludge, crystallized salt called salt cake, and salt solutions. This waste is being converted to waste forms stable for long term storage. In one of the processes, soluble salts are washed from HLW sludge in preparation for vitrification. At present, sludge is batch washed in a waste tank with one or no reuse of the wash water. Sodium hydroxide and sodium nitrite are added to the wash water for tank corrosion protection; the large volumes of spent wash water are recycled to the evaporator system; additional salt cake is produced; and sodium carbonate is formed in the washed sludge during storage by reaction with CO 2 from the air. High costs and operational concerns with the current washing process prompts DOE and WSRC to seek an improved washing method. A new method should take full advantage of the physical/chemical properties of sludge, experience from other technical disciplines, processing rate requirements, inherent process safety, and use of proven processes and equipment. Counter current solids washing is a common process in the minerals processing and chemical industries. Washing circuits can be designed using thickeners, filters or centrifuges. Realizing the special needs of nuclear work and the low processing rates required, a Counter Current Decantation (CCD) circuit is proposed using small thickeners and fluidic pumps

  14. Axion mediated photon to dark photon mixing

    Energy Technology Data Exchange (ETDEWEB)

    Ejlli, Damian [Novosibirsk State University, Department of Physics, Novosibirsk (Russian Federation); Laboratori Nazionali del Gran Sasso, Theory Group, Assergi, L' Aquila (Italy)

    2018-01-15

    The interaction between the dark/mirror sector and the ordinary sector is considered, where the two sectors interact with each other by sharing the same QCD axion field. This feature makes the mixing between ordinary and dark/mirror photons in ordinary and dark electromagnetic fields possible. Perturbative solutions of the equations of motion describing the evolution of fields in ordinary and dark external magnetic fields are found. User-friendly quantities such as transition probability rates and Stokes parameters are derived. Possible astrophysical and cosmological applications of this model are suggested. (orig.)

  15. The irreducible photon

    Science.gov (United States)

    Andrews, David L.

    2009-08-01

    In recent years it has become evident that the primary concept of the photon has multiple interpretations, with widely differing secondary connotations. Despite the all-pervasive nature of this concept in science, some of the ancillary properties with which the photon is attributed in certain areas of application sit uneasily alongside those invoked in other areas. Certainly the range of applications extends far beyond what was envisaged in the original conception, now entering subjects extending from elementary particle physics and cosmology through to spectroscopy, statistical mechanics and photochemistry. Addressing this diverse context invites the question: What is there, that it is possible to assert as incontrovertibly true about the photon? Which properties are non-controversial, if others are the subject of debate? This paper describes an attempt to answer these questions, establishing as far as possible an irreducible core of what can rightly be asserted about the photon, and setting aside some of what often is, but should never be so asserted. Some of the more bewildering difficulties and differences of interpretation owe their origin to careless descriptions, highlighting a need to guard semantic precision; although simplifications are frequently and naturally expedient for didactic purposes, they carry the risk of becoming indelible. Focusing on such issues, the aim is to identify how much or how little about the photon can be regarded as truly non-controversial.

  16. Nonlinear silicon photonics

    Science.gov (United States)

    Tsia, Kevin K.; Jalali, Bahram

    2010-05-01

    An intriguing optical property of silicon is that it exhibits a large third-order optical nonlinearity, with orders-ofmagnitude larger than that of silica glass in the telecommunication band. This allows efficient nonlinear optical interaction at relatively low power levels in a small footprint. Indeed, we have witnessed a stunning progress in harnessing the Raman and Kerr effects in silicon as the mechanisms for enabling chip-scale optical amplification, lasing, and wavelength conversion - functions that until recently were perceived to be beyond the reach of silicon. With all the continuous efforts developing novel techniques, nonlinear silicon photonics is expected to be able to reach even beyond the prior achievements. Instead of providing a comprehensive overview of this field, this manuscript highlights a number of new branches of nonlinear silicon photonics, which have not been fully recognized in the past. In particular, they are two-photon photovoltaic effect, mid-wave infrared (MWIR) silicon photonics, broadband Raman effects, inverse Raman scattering, and periodically-poled silicon (PePSi). These novel effects and techniques could create a new paradigm for silicon photonics and extend its utility beyond the traditionally anticipated applications.

  17. Fuel Effective Photonic Propulsion

    Science.gov (United States)

    Rajalakshmi, N.; Srivarshini, S.

    2017-09-01

    With the entry of miniaturization in electronics and ultra-small light-weight materials, energy efficient propulsion techniques for space travel can soon be possible. We need to go for such high speeds so that the generation’s time long interstellar missions can be done in incredibly short time. Also renewable energy like sunlight, nuclear energy can be used for propulsion instead of fuel. These propulsion techniques are being worked on currently. The recently proposed photon propulsion concepts are reviewed, that utilize momentum of photons generated by sunlight or onboard photon generators, such as blackbody radiation or lasers, powered by nuclear or solar power. With the understanding of nuclear photonic propulsion, in this paper, a rough estimate of nuclear fuel required to achieve the escape velocity of Earth is done. An overview of the IKAROS space mission for interplanetary travel by JAXA, that was successful in demonstrating that photonic propulsion works and also generated additional solar power on board, is provided; which can be used as a case study. An extension of this idea for interstellar travel, termed as ‘Star Shot’, aims to send a nanocraft to an exoplanet in the nearest star system, which could be potentially habitable. A brief overview of the idea is presented.

  18. Photonics for life.

    Science.gov (United States)

    Cubeddu, Rinaldo; Bassi, Andrea; Comelli, Daniela; Cova, Sergio; Farina, Andrea; Ghioni, Massimo; Rech, Ivan; Pifferi, Antonio; Spinelli, Lorenzo; Taroni, Paola; Torricelli, Alessandro; Tosi, Alberto; Valentini, Gianluca; Zappa, Franco

    2011-01-01

    Light is strictly connected with life, and its presence is fundamental for any living environment. Thus, many biological mechanisms are related to light interaction or can be evaluated through processes involving energy exchange with photons. Optics has always been a precious tool to evaluate molecular and cellular mechanisms, but the discovery of lasers opened new pathways of interactions of light with biological matter, pushing an impressive development for both therapeutic and diagnostic applications in biomedicine. The use of light in different fields has become so widespread that the word photonics has been utilized to identify all the applications related to processes where the light is involved. The photonics area covers a wide range of wavelengths spanning from soft X-rays to mid-infrared and includes all devices related to photons as light sources, optical fibers and light guides, detectors, and all the related electronic equipment. The recent use of photons in the field of telecommunications has pushed the technology toward low-cost, compact, and efficient devices, making them available for many other applications, including those related to biology and medicine where these requirements are of particular relevance. Moreover, basic sciences such as physics, chemistry, mathematics, and electronics have recognized the interdisciplinary need of biomedical science and are translating the most advanced researches into these fields. The Politecnico school has pioneered many of them,and this article reviews the state of the art of biomedical research at the Politecnico in the field internationally known as biophotonics.

  19. Antigravity Acts on Photons

    Science.gov (United States)

    Brynjolfsson, Ari

    2002-04-01

    Einstein's general theory of relativity assumes that photons don't change frequency as they move from Sun to Earth. This assumption is correct in classical physics. All experiments proving the general relativity are in the domain of classical physics. This include the tests by Pound et al. of the gravitational redshift of 14.4 keV photons; the rocket experiments by Vessot et al.; the Galileo solar redshift experiments by Krisher et al.; the gravitational deflection of light experiments by Riveros and Vucetich; and delay of echoes of radar signals passing close to Sun as observed by Shapiro et al. Bohr's correspondence principle assures that quantum mechanical theory of general relativity agrees with Einstein's classical theory when frequency and gravitational field gradient approach zero, or when photons cannot interact with the gravitational field. When we treat photons as quantum mechanical particles; we find that gravitational force on photons is reversed (antigravity). This modified theory contradicts the equivalence principle, but is consistent with all experiments. Solar lines and distant stars are redshifted in accordance with author's plasma redshift theory. These changes result in a beautiful consistent cosmology.

  20. Multiple photon resonances

    International Nuclear Information System (INIS)

    Elliott, C.J.; Feldman, B.J.

    1979-02-01

    A detailed theoretical analysis is presented of the interaction of intense near-resonant monochromatic radiation with an N-level anharmonic oscillator. In particular, the phenomenon of multiple photon resonance, the process by which an N-level system resonantly absorbs two or more photons simultaneously, is investigated. Starting from the Schroedinger equation, diagrammatic techniques are developed that allow the resonant process to be analyzed quantitatively, in analogy with well-known two-level coherent phenomena. In addition, multiple photon Stark shifts of the resonances, shifts absent in two-level theory, are obtained from the diagrams. Insights into the nature of multiple photon resonances are gained by comparing the quantum mechanical system with classical coupled pendulums whose equations of motion possess identical eigenvalues and eigenvectors. In certain limiting cases, including that of the resonantly excited N-level harmonic oscillator and that of the equally spaced N-level system with equal matrix elements, analytic results are derived. The influence of population relaxation and phase-disrupting collisions on the multiple photon process are also analyzed, the latter by extension of the diagrammatic technique to the density matrix equations of motion. 11 figures

  1. Subwavelength silicon photonics

    International Nuclear Information System (INIS)

    Cheben, P.; Bock, P.J.; Schmid, J.H.; Lapointe, J.; Janz, S.; Xu, D.-X.; Densmore, A.; Delage, A.; Lamontagne, B.; Florjanczyk, M.; Ma, R.

    2011-01-01

    With the goal of developing photonic components that are compatible with silicon microelectronic integrated circuits, silicon photonics has been the subject of intense research activity. Silicon is an excellent material for confining and manipulating light at the submicrometer scale. Silicon optoelectronic integrated devices have the potential to be miniaturized and mass-produced at affordable cost for many applications, including telecommunications, optical interconnects, medical screening, and biological and chemical sensing. We review recent advances in silicon photonics research at the National Research Council Canada. A new type of optical waveguide is presented, exploiting subwavelength grating (SWG) effect. We demonstrate subwavelength grating waveguides made of silicon, including practical components operating at telecom wavelengths: input couplers, waveguide crossings and spectrometer chips. SWG technique avoids loss and wavelength resonances due to diffraction effects and allows for single-mode operation with direct control of the mode confinement by changing the refractive index of a waveguide core over a range as broad as 1.6 - 3.5 simply by lithographic patterning. The light can be launched to these waveguides with a coupling loss as small as 0.5 dB and with minimal wavelength dependence, using coupling structures similar to that shown in Fig. 1. The subwavelength grating waveguides can cross each other with minimal loss and negligible crosstalk which allows massive photonic circuit connectivity to overcome the limits of electrical interconnects. These results suggest that the SWG waveguides could become key elements for future integrated photonic circuits. (authors)

  2. Reconfigurable topological photonic crystal

    Science.gov (United States)

    Shalaev, Mikhail I.; Desnavi, Sameerah; Walasik, Wiktor; Litchinitser, Natalia M.

    2018-02-01

    Topological insulators are materials that conduct on the surface and insulate in their interior due to non-trivial topology of the band structure. The edge states on the interface between topological (non-trivial) and conventional (trivial) insulators are topologically protected from scattering due to structural defects and disorders. Recently, it was shown that photonic crystals (PCs) can serve as a platform for realizing a scatter-free propagation of light waves. In conventional PCs, imperfections, structural disorders, and surface roughness lead to significant losses. The breakthrough in overcoming these problems is likely to come from the synergy of the topological PCs and silicon-based photonics technology that enables high integration density, lossless propagation, and immunity to fabrication imperfections. For many applications, reconfigurability and capability to control the propagation of these non-trivial photonic edge states is essential. One way to facilitate such dynamic control is to use liquid crystals (LCs), which allow to modify the refractive index with external electric field. Here, we demonstrate dynamic control of topological edge states by modifying the refractive index of a LC background medium. Background index is changed depending on the orientation of a LC, while preserving the topology of the system. This results in a change of the spectral position of the photonic bandgap and the topological edge states. The proposed concept might be implemented using conventional semiconductor technology, and can be used for robust energy transport in integrated photonic devices, all-optical circuity, and optical communication systems.

  3. Sensitivity of the IRD whole-body counter for in vivo measurements in the case of accidental intakes

    Energy Technology Data Exchange (ETDEWEB)

    Dantas, B.M.; Lucena, E.A.; Dantas, A.L.A., E-mail: bmdantas@ird.gov.br, E-mail: eder@ird.gov.br, E-mail: adantas@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil), Laboratorio de Monitoracao In Vivo

    2016-07-01

    Intakes of radionuclides by humans may occur in the fuel cycle, nuclear medicine, biological research and in TENORM industries and in case of accidents involving workers and the general public. In vivo monitoring is recognized as a useful tool for the evaluation of such exposures. The IRD whole-body counter consists of a shielded room equipped with four HPGe and two NaI(Tl) detectors. The system is able to identify and quantify photon emitters in the range from 10 to 3000 keV. The minimum detectable activities for most of the radionuclides of interest allow occupational monitoring as well evaluation of accidental intakes. (author)

  4. X-ray proportional counter for the Viking Lander

    International Nuclear Information System (INIS)

    Glesius, F.L.; Kroon, J.C.; Castro, A.J.; Clark, B.C.

    1978-01-01

    A set of four sealed proportional counters with optimized energy response is employed in the X-ray fluorescence spectrometer units aboard the two Viking Landers. The instruments have provided quantitative elemental analyses of soil samples taken from the Martian surface. This paper discusses the design and development of these miniature proportional counters, and describes their performance on Mars

  5. Output pulse height distribution of the GM counters

    International Nuclear Information System (INIS)

    Zhang Songshou; Xiong Jianping

    1995-01-01

    The GM counters are the radiation detectors most in use. It has special advantages compared with other detectors. This paper introduces the output pulse height distribution of the GM counters, gives the measuring instruments and methods. The measuring results, some discussions, and useful conclusion are given as well

  6. The Counter Terrorist Classroom: Religion, Education, and Security

    Science.gov (United States)

    Gearon, Liam

    2013-01-01

    The article identifies international cases--from the United States, Europe, and the United Nations--of an emergent interface of religion, education, and security. This is manifest in the uses of religion in education to counter religious extremism, the notional "counter terrorist classroom." To avoid an over-association of extremism with…

  7. Counter-terrorism strategies in Indonesia, Algeria and Saudi Arabia

    NARCIS (Netherlands)

    Meijer, R.; Hasan, Noorhaidi; Hendriks, B.; Janssen, F.

    2012-01-01

    This report is the result of a year-long study, conducted from March 2010 to March 2011, of the counter-terrorist strategies of three countries: Indonesia, Algeria and Saudi Arabia. The aim of this study was to acquire insight into the counter-terrorist strategies of these countries, to analyse

  8. Analysis of Cherenkov counter efficiencies for E691

    International Nuclear Information System (INIS)

    Cremaldi, L.; Elliott, J.; Gibney, M.; Nauenberg, U.

    1985-01-01

    A program is outlined which simulates Cherenkov counters. The program can compute the effect of the magnetic field on the efficiencies of Cherenkov counters. It also tells what cone to mirror distance gives the highest collection efficiency and at which target position should the laser be placed to represent the direction of the actual Cherenkov light the mirror sees

  9. Presettable up-down CAMAC counter for 24 bit

    International Nuclear Information System (INIS)

    Kuhn, K.; Meyer, U.; Weidhase, F.

    1976-01-01

    A module containing a presettable binary up-down CAMAC counter for 24 bit is described. The use of dataway is discussed. As an example for application in nuclear physics, control of beam position by the up-down counter is illustrated

  10. Lessons from History for Counter- Terrorism Strategic Communications

    NARCIS (Netherlands)

    Ingram, H.J.; Reed, A.G.

    2016-01-01

    Drawing on the Counter-terrorism Strategic Communication (CTSC) Project’s research paper “A Brief History of Propaganda during Conflict“, this Policy Brief lays out the key policy-relevant lessons for developing effective counter-terrorism strategic communications. It presents a framework of

  11. Counter-Buffing: A Visual Criticism of Guerrilla Advertising

    Science.gov (United States)

    Lauzon, Robb Conrad; Cooke, Laquana

    2017-01-01

    This article addresses and explores hip-hop's reclamation of space using transit as a public bulletin. It is situated within counter-publics discourse and couched in the theoretical frameworks offered by visual rhetorical theory. This article also discusses hip-hop counter-publics through guerrilla advertising by former graffiti artists, SKI and…

  12. Counter diffusion of zinc and iron in alluvial soil

    International Nuclear Information System (INIS)

    Rattan, R.K.; Deb, D.L.

    1980-01-01

    Half cell technique showed that an increase in moisture tension and CaCO 3 content caused reduction in the counter diffusion coefficients of zinc and iron in an alluvial soil. Increases in bulk density, ambient temperature and concentration of synthetic chelating agents e.g. EDTA and DTPA increased the counter diffusion coefficients of both zinc and iron. (author)

  13. The IFIN-HH triple coincidence liquid scintillation counter

    CSIR Research Space (South Africa)

    Razdolescu, AC

    2006-10-01

    Full Text Available at IFIN-HH using a 3 H standard. The performances of the IFIN-HH TDCR counter was checked against the measurement results of the TDCR counters of CSIR NML (South Africa), RC (Poland) and LNHB (France). A set of ready-to-measure Ni-63 sources in liquid...

  14. Beam test of Cherenkov counter prototype for ZDF setup

    International Nuclear Information System (INIS)

    Kacharava, A.K.; Macharashvili, G.G.; Nioradze, M.S.; Komarov, V.I.; Sopov, V.S.; Chernyshev, V.P.

    1995-01-01

    We describe a Cherenkov counter of total internal reflection for particle separation in the momentum range where all types of particles radiate Cherenkov light. The Cherenkov counter prototype with the lucite radiator was tested on the secondary beam of the ITEP (Moscow) accelerator. Dependence of the photomultiplier pulse height on the particle entrance angle was clearly observed. 4 refs., 4 figs

  15. A proportional counter for efficient backscatter Moessbauer effect spectroscopy

    International Nuclear Information System (INIS)

    Pawlowski, Z.; Marzec, J.; Cudny, W.; Holnicka, J.; Walentek, J.

    1979-01-01

    The authors present a novel gas-tight proportional counter with flat beryllium windows for backscatter Moessbauer spectroscopy. The krypton-filled counter has a geometry that approaches 2π and a resolution of 12% fwhm for the 14.4 keV line of 57 Fe, and is easy to manufacture. (Auth.)

  16. Mesoscopic photon heat transistor

    DEFF Research Database (Denmark)

    Ojanen, T.; Jauho, Antti-Pekka

    2008-01-01

    We show that the heat transport between two bodies, mediated by electromagnetic fluctuations, can be controlled with an intermediate quantum circuit-leading to the device concept of a mesoscopic photon heat transistor (MPHT). Our theoretical analysis is based on a novel Meir-Wingreen-Landauer-typ......We show that the heat transport between two bodies, mediated by electromagnetic fluctuations, can be controlled with an intermediate quantum circuit-leading to the device concept of a mesoscopic photon heat transistor (MPHT). Our theoretical analysis is based on a novel Meir......-Wingreen-Landauer-type of conductance formula, which gives the photonic heat current through an arbitrary circuit element coupled to two dissipative reservoirs at finite temperatures. As an illustration we present an exact solution for the case when the intermediate circuit can be described as an electromagnetic resonator. We discuss...

  17. Bio-optofluidics and Bio-photonics: Programmable Phase Optics activities at DTU Fotonik

    DEFF Research Database (Denmark)

    Bañas, Andrew Rafael; Palima, Darwin; Pedersen, Finn

    We present ongoing research and development activities for constructing a compact next generation BioPhotonics Workstation and a Bio-optofluidic Cell Sorter (cell-BOCS) for all-optical micromanipulation platforms utilizing low numerical aperture beam geometries. Unlike conventional high NA optical...... tweezers, the BioPhotonics workstation is e.g. capable of long range 3D manipulation. This enables a variety of biological studies such as manipulation of intricate microfabricated assemblies or for automated and parallel optofluidic cell sorting. To further reduce its overhead, we propose ways of making...... the BioPhotonics Workstation platform more photon efficient by studying the 3D distribution of the counter propagating beams and utilizing the Generalized Phase Contrast (GPC) method for illuminating the applied spatial light modulators....

  18. Graphene-based photonic crystal

    International Nuclear Information System (INIS)

    Berman, Oleg L.; Boyko, Vladimir S.; Kezerashvili, Roman Ya.; Kolesnikov, Anton A.; Lozovik, Yurii E.

    2010-01-01

    A novel type of photonic crystal formed by embedding a periodic array of constituent stacks of alternating graphene and dielectric discs into a background dielectric medium is proposed. The photonic band structure and transmittance of such photonic crystal are calculated. The graphene-based photonic crystals can be used effectively as the frequency filters and waveguides for the far infrared region of electromagnetic spectrum. Due to substantial suppression of absorption of low-frequency radiation in doped graphene the damping and skin effect in the photonic crystal are also suppressed. The advantages of the graphene-based photonic crystal are discussed.

  19. Photon detector for MEGA

    International Nuclear Information System (INIS)

    Gagliardi, C.A.; Tribble, R.E.

    1991-01-01

    During the past year, we have continued work on the photon detector for the MEGA experiment at Los Alamos, a search for the rare decay μ → eγ to a sensitivity of a few parts in 10 13 . The MEGA photon detector is designed to observe the 52.38 MeV photon produced in a μ → eγ decay with an energy resolution of 1.25 MeV, a position resolution of 2 x 5 mm 2 , a directional resolution of 10 degrees, a time resolution of 500 ps, and an efficiency of 7%. It will consists of four independent concentric cylindrical pair spectrometers mounted within a 1.5 T magnetic field produced by a superconducting solenoid magnet. Each pair spectrometer includes two thin Pb foils to convert photons into e + e - pairs, and thereby, determine both their locations and their vector momenta. The inner drift chamber layer includes a delay line cathode to determine the z coordinates needed for track reconstruction. An MWPC located between two Pb layers identifies the conversion layer so that energy loss corrections may be applied, while plastic scintillators provide timing information. Our, group together with a group from the University of Houston, is responsible for the design and construction of the photon detector, as well as developing the computer codes necessary for Monte Carlo simulations and data analysis. During the past year, our efforts have focused primarily on two tasks, delay line cathode read-out and software development. This report describes our recent work on delay lines and data analysis along with a discussion of the new plans for multiplexing in the photon arm

  20. Unconditionally secure key distillation from multi-photons in a single-photon polarization based quantum key distribution

    CERN Document Server

    Tamaki, K

    2005-01-01

    In this presentation, we show some counter-examples to a naive belief that the security of QKD is based on no-cloning theorem. One example is shown by explicitly proving that one can indeed generate an unconditionally secure key from Alice's two-photon emission part in "SARG04 protocol" proposed by V. Scarani et al, in Phys. Rev. Lett. 92, 057901 (2004). This protocol differs from BB84 only in the classical communication. It is, thus, interesting to see how only the classical communication of QKD protocol might qualitatively change its security. We also show that one can generate an unconditionally secure key from the single to the four-photon part in a generalized SARG04 that uses six states. Finally, we also compare the bit error rate threshold of these protocols with the one in BB84 and the original six-state protocol assuming a depolarizing channel.

  1. Design of a novel quantum reversible ternary up-counter

    Science.gov (United States)

    Houshmand, Pouran; Haghparast, Majid

    2015-08-01

    Reversible logic has been recently considered as an interesting and important issue in designing combinational and sequential circuits. The combination of reversible logic and multi-valued logic can improve power dissipation, time and space utilization rate of designed circuits. Only few works have been reported about sequential reversible circuits and almost there are no paper exhibited about quantum ternary reversible counter. In this paper, first we designed 2-qutrit and 3-qutrit quantum reversible ternary up-counters using quantum ternary reversible T-flip-flop and quantum reversible ternary gates. Then we proposed generalized quantum reversible ternary n-qutrit up-counter. We also introduced a new approach for designing any type of n-qutrit ternary and reversible counter. According to the results, we can conclude that applying second approach quantum reversible ternary up-counter is better than the others.

  2. Multi-level modelling of the response of the ultraminiature proportional counter: gas gain phenomena and pulse height spectra

    International Nuclear Information System (INIS)

    Olko, P.; Moutarde, C.; Segur, P.

    1995-01-01

    The ultraminiature proportional counters, UMC, unique radiation detectors for monitoring high intensity therapy fields, designed by Kliauga and operated at Columbia University (USA), have yielded a number of pulse height distributions for photons, neutrons and ions at simulated diameters of 5-50 nm. Monte Carlo calculations of the gas gain in such a counter questioned the possibility of achieving proportionally at such low simulated diameters. The response of the UMC has now been modelled taking into account both fluctuations of energy deposited in the counter volume and its calculated gas gain. Energy deposition was calculated using the MOCA-14, MOCA-8 and TRION codes, whereby distributions of ionisations d(j) after irradiations with 137 Cs, 15 MeV neutrons and 7 MeV.amu -1 deuterons were obtained. Monte Carlo calculations of electron avalanches in UMC show that the size of the single-electron avalanche P(n) reaching the anode depends strongly on the location of the primary ionisation within the counter volume. Distributions of the size of electron avalanches for higher numbers of primary ionisations, P *j (n), were obtained by successive convolutions of P(n). Finally, the counter response was obtained by weighting P *j (n) over d(j) distributions. On comparing the measured and calculated spectra it was concluded that the previously proposed single-electron peak calibration method might not be valid for the UMC due to the excessive width and overlap of electron avalanche distributions. Better agreement between the measured and calculated spectra is found if broader electron avalanche distributions than those used in the present calculations, are assumed. (author)

  3. Models for Photon-photon Total Cross-sections

    OpenAIRE

    Godbole, RM; Grau, A; Pancheri, G

    1999-01-01

    We present here a brief overview of recent models describing the photon-photon cross-section into hadrons. We shall show in detail results from the eikonal minijet model, with and without soft gluon summation.

  4. Photonic band gap engineering in 2D photonic crystals

    Indian Academy of Sciences (India)

    Department of Applied Physics, Delhi College of Engineering, Faculty of Technology. (University of ... Photonic crystal; photonic band gap; plane-wave expansion method. PACS Nos 71.20 .... Numerical analysis and results. To obtain the ...

  5. Workplace photon radiation fields

    International Nuclear Information System (INIS)

    Burgess, P.H.; Bartlett, D.T.; Ambrosi, P.

    1999-01-01

    The knowledge of workplace radiation fields is essential for measures in radiation protection. Information about the energy and directional distribution of the incident photon radiation was obtained by several devices developed by the National Radiation Protection Board, United Kingdom, by the Statens Stralskyddsinstitut, Sweden, together with EURADOS and by the Physikalisch-Technische Bundesanstalt, Germany. The devices are described and some results obtained at workplaces in nuclear industry, medicine and science in the photon energy range from 20 keV to 7 MeV are given. (author)

  6. Photon mass experiment

    International Nuclear Information System (INIS)

    Crandall, R.E.

    1983-01-01

    A Coulomb null experiment is described that enables physics students to obtain rigorous upper bounds on photon mass. The experimenter searches for subnanovolt signals that would escape a closed shell were photon mass to be positive. The approach can be adapted for several college levels. At the simplest level, a ''miniature'' low-cost experiment allows a student to verify the exponent ''-2'' in Coulomb's law to eight or more decimal places. An advanced student given a full-size apparatus (at greater cost) can obtain mass bounds very close to the established laboratory limit

  7. A fast VUV light pulser for testing ring-imaging Cerenkov counters

    International Nuclear Information System (INIS)

    Margulies, S.; Ozelis, J.

    1986-01-01

    A simple, fast, VUV light pulser for testing a TMAE-based, time-projection-chamber-type photon detector for a ring-imaging Cerenkov counter is described. The pulser consists of an automobile spark plug fired in a controlled atmosphere by a relaxation oscillator. The resulting VUV spectrum, spark-current pulse, and light pulse were investigated for hydrogen, xenon, krypton, and nitrogen fills. The best pulse (3.5 ns FWHM) was obtained with hydrogen at 60 kPa absolute pressure. Xenon was, generally, unsuitable because it continued to emit light for more than a microsecond after excitation. With krypton and nitrogen, no light was emitted in the wavelength region of interest except for a series of sharp lines attributable to the electrodes

  8. GUIDE 7. A general program for evaluating the properties of scintillation and Cerenkov counter optical systems

    International Nuclear Information System (INIS)

    Massam, T.

    1976-01-01

    GUIDE 7 is a design tool for optical systems which are constructed predominantly from reflecting surfaces. A wide range of surface forms and qualities may be chosen and there is provision for the user to extend the range of applicability of the program. Available facilities include estimation of light collection efficiencies, simulation of the space-time intensity distributions of photons arriving at a detector, optimization of the parameters of focusing systems. The report gives a complete description of the program, including user-defined routines. A large-area time-of-flight counter and ray-tracing for a parabolic mirror are treated as examples, detailing the input data and showing the corresponding output. The derivation of the vector algorithms used in the program is also included. (Auth.)

  9. Passive assay of plutonium metal plates using a fast-neutron multiplicity counter

    Energy Technology Data Exchange (ETDEWEB)

    Di Fulvio, A., E-mail: difulvio@umich.edu [Department of Nuclear Engineering & Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Shin, T.H.; Jordan, T.; Sosa, C.; Ruch, M.L.; Clarke, S.D. [Department of Nuclear Engineering & Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Chichester, D.L. [Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Pozzi, S.A. [Department of Nuclear Engineering & Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States)

    2017-05-21

    We developed a fast-neutron multiplicity counter based on organic scintillators (EJ-309 liquid and stilbene). The system detects correlated photon and neutron multiplets emitted by fission reactions, within a gate time of tens of nanoseconds. The system was used at Idaho National Laboratory to assay a variety of plutonium metal plates. A coincidence counting strategy was used to quantify the {sup 240}Pu effective mass of the samples. Coincident neutrons, detected within a 40-ns coincidence window, show a monotonic trend, increasing with the {sup 240}Pu-effective mass (in this work, we tested the 0.005–0.5 kg range). After calibration, the system estimated the {sup 240}Pu effective mass of an unknown sample ({sup 240}Pu{sub eff} >50 g) with an uncertainty lower than 1% in a 4-min assay time.

  10. Bases for calibration of whole body counters using anthropomorphic physical simulators

    International Nuclear Information System (INIS)

    Dantas, Bernardo Maranhao

    1998-01-01

    The quantification of radionuclides in the human body can be carried out through in vivo measurements performed in facilities generically called whole body counters. The calibration of such units is usually done by using physical anthropomorphic phantoms, which can be defined as artificial structures with geometrical characteristics and attenuation properties similar to the living tissues. This work presents the development of the phantoms necessary to the monitoring of the internal contamination by the radionuclides manipulated in Brazil. It also presents the procedures for the calibration of the detectors used for the in vivo measurements. The developed phantoms are applied in the determination of radionuclides deposited in specific organs, such as Th-232 and Am-241 in the lungs and skull, isotopes of iodine in the thyroid and photon emitters in the energy range from 100 to 3000 keV in the whole body. (author)

  11. Influence of tube volume on measurement uncertainty of GM counters

    Directory of Open Access Journals (Sweden)

    Stanković Koviljka Đ.

    2010-01-01

    Full Text Available GM counters are often used in radiation detection since they generate a strong signal which can be easily detected. The working principal of a GM counter is based on the interaction of ionizing radiation with the atoms and molecules of the gas present in the counter's tube. Free electrons created as a result of this interaction become initial electrons, i. e. start an avalanche process which is detected as a pulse of current. This current pulse is independent of the energy imparted on the gas, that being the main difference between a GM counter and the majority of other radiation detectors. In literature, the dependence on the incidence of radiation energy, tube's orientation and characteristics of the reading system are quoted as the main sources of measurement uncertainty of GM counters. The aim of this paper is to determine the dependence of measurement uncertainty of a GM counter on the volume of its counter's tube. The dependence of the pulse current on the size of the counter's tube has, therefore, been considered here, both in radial and parallel geometry. The initiation and expansion of the current pulse have been examined by means of elementary processes of electrical discharge such as the Markov processes, while the changes in the counter's tube volume were put to test by the space - time enlargement law. The random variable known as the 'current pulse in the counter's tube' (i. e. electrical breakdown of the electrode configuration has also been taken into account and an appropriate theoretical distribution statistically determined. Thus obtained theoretical results were then compared to corresponding experimental results established in controlled laboratory conditions.

  12. Recent developments in the theory of photon-photon collisions

    International Nuclear Information System (INIS)

    Brodsky, S.J.

    1984-09-01

    Over the past few years the field of photon-photon collisions has emerged as one of the best testing grounds for QCD, particularly in the area of exclusive and inclusive hard scattering processes, exotic resonance production, and detailed tests of the coupling of real and virtual photons to the quark current. In this summary of contributed papers, I will briefly review recent theoretical progress in the analysis of two-photon reactions and possible directions for future work. 29 references

  13. Calibration of the LDI/CDTN Whole Body Counter using three physical phantoms

    Energy Technology Data Exchange (ETDEWEB)

    Paiva, F.G.; Fonseca, T.C.F. [Universidade Federal de Minas Gerais (DEN/UFMG), Belo Horizonte, MG (Brazil). Dep. de Engenharia Nuclear; Mendes, B.M.; Silva, T.A. da; Lacerda, M.A.S.; Pinto, J.R.; Prates, S.; Filho, N.N.A., E-mail: fgpaiva92@gmail.com [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte/MG (Brazil); Dantas, A.L.A.; Dantas, B.M. [Instituto de Radioproteção e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2017-07-01

    The Laboratory of Internal Dosimetry of the Center for Development of Nuclear Technology (LDI/CDTN) is responsible for routine monitoring of internal contamination of the Individuals Occupationally Exposed (IOEs) at the Unit for Research and Production of Radiopharmaceuticals (UPPR/CDTN), the Research Reactor TRIGA-IPR-R1/CDTN and other workplaces of the institute where there is a risk of accidental intakes. Additionally, LDI supports the Institute of Radiation Protection and Dosimetry (IRD/CNEN) to attend radiological emergencies. The determination of photon emitting radionuclides in the human body requires the use of calibration techniques in different counting geometries for converting the count rates into activity in organs and tissues. This paper presents and discusses the calibration of the LDI/CDTN Whole Body Counter (WBC) using a standard BOMAB phantom (Bottle Mannequin Absorber) compared to a home-made phantom produced with Polyethylene Terephthalate bottles (PET). Initially, the BOMAB was filled with a cocktail containing {sup 60}Co, {sup 137}Cs and {sup 133}Ba. The phantom was counted at the LDI whole body counter and an Efficiency x Energy curve was obtained. Subsequently the PET-BOMAB was filled with the same standard source and a second curve was determined. The efficiency values in each region of interest as well as the shape of both curves were found to be equivalent. The results validate the use of the PET-BOMAB for the calibration of whole body geometry applied to the measurement of high energy photon emitting radionuclides in the energy region evaluated in this work. (author)

  14. A compact and high efficiency GAGG well counter for radiocesium concentration measurements

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Seiichi, E-mail: s-yama@met.nagoya-u.ac.jp; Ogata, Yoshimune

    2014-07-01

    After the Fukushima nuclear disaster, social concern about radiocesium ({sup 137}Cs and {sup 134}Cs) contamination in food increased. However, highly efficient instruments that can measure low level radioactivity are quite expensive and heavy. A compact, lightweight, and reliable radiation detector that can inexpensively monitor low level radiocesium is highly desired. We developed a compact and highly efficient radiocesium detector to detect ∼32 keV X-rays from radiocesium instead of high energy gamma photons. A 1-mm thick GAGG scintillator was selected to effectively detect ∼32 keV X-rays from {sup 137}Cs to reduce the influence of ambient radiation. Four sets of 25 mm×25 mm×1 mm GAGG plates, each of which was optically coupled to a triangular-shaped light guide, were optically coupled to a photomultiplier tube (PMT) to form a square-shaped well counter. Another GAGG plate was directly optically coupled to the PMT to form its bottom detector. The energy resolution of the GAGG well counter was 22.3% FWHM for 122 keV gamma rays and 32% FWHM for ∼32 keV X-rays. The counting efficiency for the X-rays from radiocesium (mixture of {sup 137}Cs and {sup 134}Cs) was 4.5%. In measurements of the low level radiocesium mixture, a photo-peak of ∼32 keV X-rays can clearly be distinguished from the background. The minimum detectable activity (MDA) was estimated to be ∼100 Bq/kg for 1000 s measurement. The results show that our developed GAGG well counter is promising for the detection of radiocesium in food.

  15. QCD measurements in photon-photon collisions at LEP

    OpenAIRE

    Csilling, Akos

    2001-01-01

    An overview of the latest results of the LEP collaborations on QCD measurements in photon-photon collisions is presented, including measurements of the total hadronic cross-section, the production of heavy quarks and dijets and the structure functions of real and virtual photons.

  16. High brightness single photon sources based on photonic wires

    DEFF Research Database (Denmark)

    Claudon, J.; Bleuse, J.; Bazin, M.

    2009-01-01

    We present a novel single-photon-source based on the emission of a semiconductor quantum dot embedded in a single-mode photonic wire. This geometry ensures a very large coupling (> 95%) of the spontaneous emission to the guided mode. Numerical simulations show that a photon collection efficiency...

  17. Tests of perturbative quantum chromodynamics in photon-photon collisions

    International Nuclear Information System (INIS)

    Brodsky, S.J.

    1979-01-01

    The production of hadrons in the collision of two photons via the process e + e - → e + e - X can provide an ideal laboratory for testing many of the features of the photon's hadronic interactions, especially its short-distance aspects. That part of two-photon physics which is particularly relevant to tests of perturbative QCD is reviewed here. 6 figures

  18. Trends in the development of large area photon detectors for Cherenkov light imaging applications

    CERN Document Server

    Nappi, E

    2003-01-01

    Since the successful operations of hi-tech devices at OMEGA, DELPHI and SLD, the technique of Cherenkov light imaging has gone through an impressive and fruitful evolution driven by the conception of novel large area photon detectors. The well-assessed potentialities of thin CsI films, employed as reflective photoconverters in gas counters operated at atmospheric pressure, will be compared with the promising features of hybrid and multianode vacuum photomultipliers. Recently proposed single-photon gaseous detectors based on GEMs will also be reviewed.

  19. Experimental validation of GADRAS's coupled neutron-photon inverse radiation transport solver

    International Nuclear Information System (INIS)

    Mattingly, John K.; Mitchell, Dean James; Harding, Lee T.

    2010-01-01

    Sandia National Laboratories has developed an inverse radiation transport solver that applies nonlinear regression to coupled neutron-photon deterministic transport models. The inverse solver uses nonlinear regression to fit a radiation transport model to gamma spectrometry and neutron multiplicity counting measurements. The subject of this paper is the experimental validation of that solver. This paper describes a series of experiments conducted with a 4.5 kg sphere of α-phase, weapons-grade plutonium. The source was measured bare and reflected by high-density polyethylene (HDPE) spherical shells with total thicknesses between 1.27 and 15.24 cm. Neutron and photon emissions from the source were measured using three instruments: a gross neutron counter, a portable neutron multiplicity counter, and a high-resolution gamma spectrometer. These measurements were used as input to the inverse radiation transport solver to evaluate the solver's ability to correctly infer the configuration of the source from its measured radiation signatures.

  20. Counter-terrorism threat prediction architecture

    Science.gov (United States)

    Lehman, Lynn A.; Krause, Lee S.

    2004-09-01

    This paper will evaluate the feasibility of constructing a system to support intelligence analysts engaged in counter-terrorism. It will discuss the use of emerging techniques to evaluate a large-scale threat data repository (or Infosphere) and comparing analyst developed models to identify and discover potential threat-related activity with a uncertainty metric used to evaluate the threat. This system will also employ the use of psychological (or intent) modeling to incorporate combatant (i.e. terrorist) beliefs and intent. The paper will explore the feasibility of constructing a hetero-hierarchical (a hierarchy of more than one kind or type characterized by loose connection/feedback among elements of the hierarchy) agent based framework or "family of agents" to support "evidence retrieval" defined as combing, or searching the threat data repository and returning information with an uncertainty metric. The counter-terrorism threat prediction architecture will be guided by a series of models, constructed to represent threat operational objectives, potential targets, or terrorist objectives. The approach would compare model representations against information retrieved by the agent family to isolate or identify patterns that match within reasonable measures of proximity. The central areas of discussion will be the construction of an agent framework to search the available threat related information repository, evaluation of results against models that will represent the cultural foundations, mindset, sociology and emotional drive of typical threat combatants (i.e. the mind and objectives of a terrorist), and the development of evaluation techniques to compare result sets with the models representing threat behavior and threat targets. The applicability of concepts surrounding Modeling Field Theory (MFT) will be discussed as the basis of this research into development of proximity measures between the models and result sets and to provide feedback in support of model

  1. Photon sources for absorptiometric measurements

    International Nuclear Information System (INIS)

    Witt, R.M.; Sandrik, J.M.; Cameron, J.R.

    1976-01-01

    Photon absorptiometry is defined and the requirements of photon sources for these measurements are described. Both x-ray tubes and radionuclide sources are discussed, including the advantages of each in absorptiometric systems

  2. ALICE Photon Spectrometer

    CERN Multimedia

    Kharlov, Y

    2013-01-01

    PHOS provides unique coverage of the following physics topics: - Study initial phase of the collision of heavy nuclei via direct photons, - Jet-quenching as a probe of deconfinement, studied via high Pτ ϒ and π0, - Signals of chiral-symmetry restoration, - QCD studies in pp collisions via identified neutral spectra.

  3. Photon strength functions

    International Nuclear Information System (INIS)

    Bergqvist, I.

    1976-01-01

    Methods for extracting photon strength functions are briefly discussed. We follow the Brink-Axel approach to relate the strength functions to the giant resonances observed in photonuclear work and summarize the available data on the E1, E2 and M1 resonances. Some experimental and theoretical problems are outlined. (author)

  4. Direct photon experiments

    International Nuclear Information System (INIS)

    Boeggild, H.

    1986-11-01

    The author reviews the experiments on direct photon production in hadronic collisions. After a description of the experimental methods for the study of such processes he presents some results on differential cross sections and the γ/π 0 ratio in π - p, π + p, pp, and anti pp processes as well as in reactions of π - , π + , and p on carbon. (HSI)

  5. Total photon absorption

    International Nuclear Information System (INIS)

    Carlos, P.

    1985-01-01

    Experimental methods using real photon beams for measurements of total photonuclear absorption cross section σ(Tot : E/sub γ/) are recalled. Most recent σ(Tot : E/sub γ/)results for complex nuclei and in the nucleon resonance region are presented

  6. Magnetic photon scattering

    International Nuclear Information System (INIS)

    Lovesey, S.W.

    1987-05-01

    The report reviews, at an introductory level, the theory of photon scattering from condensed matter. Magnetic scattering, which arises from first-order relativistic corrections to the Thomson scattering amplitude, is treated in detail and related to the corresponding interaction in the magnetic neutron diffraction amplitude. (author)

  7. Photon collider at TESLA

    International Nuclear Information System (INIS)

    Telnov, Valery

    2001-01-01

    High energy photon colliders (γγ, γe) based on backward Compton scattering of laser light is a very natural addition to e + e - linear colliders. In this report, we consider this option for the TESLA project. Recent study has shown that the horizontal emittance in the TESLA damping ring can be further decreased by a factor of four. In this case, the γγ luminosity in the high energy part of spectrum can reach about (1/3)L e + e - . Typical cross-sections of interesting processes in γγ collisions are higher than those in e + e - collisions by about one order of magnitude, so the number of events in γγ collisions will be more than that in e + e - collisions. Photon colliders can, certainly, give additional information and they are the best for the study of many phenomena. The main question is now the technical feasibility. The key new element in photon colliders is a very powerful laser system. An external optical cavity is a promising approach for the TESLA project. A free electron laser is another option. However, a more straightforward solution is ''an optical storage ring (optical trap)'' with a diode pumped solid state laser injector which is today technically feasible. This paper briefly reviews the status of a photon collider based on the linear collider TESLA, its possible parameters and existing problems

  8. What is a Photon?

    Indian Academy of Sciences (India)

    IAS Admin

    we say we `see' something, what we are talking about is that some photons ... Nobel Prize for his work in QED, and called it the strange theory of light and matter. Strange .... its form was assumed by him in order to get the correct expression for ...

  9. Jet production in photon-photon interactions

    International Nuclear Information System (INIS)

    Berger, C.; Genzel, H.; Lackas, W.; Pielorz, J.; Raupach, F.; Wagner, W.; Buerger, J.; Criegee, L.; Deuter, A.; Franke, G.; Gerke, C.; Knies, G.; Lewendel, B.; Meyer, J.; Michelsen, U.; Pape, K.H.; Timm, U.; Winter, G.G.; Zimmermann, W.; Zachara, M.; Ferrarotto, F.; Gaspero, M.; Stella, B.; Bussey, P.J.; Cartwright, S.L.; Dainton, J.B.; Hendry, D.; King, B.T.; Raine, C.; Scarr, J.M.; Skillicorn, I.O.; Smith, K.M.; Thomson, J.C.; Achterberg, O.; Blobel, V.; Burkart, D.; Diehlmann, K.; Feindt, M.; Kapitza, H.; Koppitz, B.; Krueger, M.; Poppe, M.; Spitzer, H.; Staa, R. van; Almeida, F.; Baecker, A.; Barreiro, F.; Brandt, S.; Derikum, K.; Grupen, C.; Meyer, H.J.; Mueller, H.; Neumann, B.; Rost, M.; Stupperich, K.; Zech, G.; Alexander, G.; Bella, G.; Gnat, Y.; Grunhaus, J.; Junge, H.; Kraski, K.; Maxeiner, C.; Maxeiner, H.; Meyer, H.; Schmidt, D.

    1987-01-01

    We present results on jet production in γγ interactions where both photons are quasi-real. The invariant masses of the hadronic system are limited to the range 4≤W vis 12 GeV/c 2 . The data approach the Quark-Parton-Model (QPM) expectation at the highest p T jet values (≥4 GeV/c). Jet production at low p T (≤1 GeV/c) can be described by a Vector Dominance derived model. The data also have a component with no apparent jet structure in the range, 1.0≤p T jet ≤4.0 GeV/c which can be described by phase space or by models of the QCD hard scattering processes γγ→qanti qg and γγ→qanti qqanti q. (orig.)

  10. Limits on the photon mass

    International Nuclear Information System (INIS)

    Vasseur, G.

    1996-03-01

    Is the photon mass strictly null as it is told in quantum electrodynamics. In fact, a coherent theory can be build with a massive photon. Experiences have been regularly led to try to make obvious an eventual non null photon mass. Superior limits more and more strict have been found. Here is given a general survey of the consequences of a non null photon mass, different methods to measure it and the achieved limits. (author). 30 refs., 1 fig

  11. Biomedical photonics handbook biomedical diagnostics

    CERN Document Server

    Vo-Dinh, Tuan

    2014-01-01

    Shaped by Quantum Theory, Technology, and the Genomics RevolutionThe integration of photonics, electronics, biomaterials, and nanotechnology holds great promise for the future of medicine. This topic has recently experienced an explosive growth due to the noninvasive or minimally invasive nature and the cost-effectiveness of photonic modalities in medical diagnostics and therapy. The second edition of the Biomedical Photonics Handbook presents fundamental developments as well as important applications of biomedical photonics of interest to scientists, engineers, manufacturers, teachers, studen

  12. Photons, photon jets, and dark photons at 750 GeV and beyond.

    Science.gov (United States)

    Dasgupta, Basudeb; Kopp, Joachim; Schwaller, Pedro

    2016-01-01

    In new physics searches involving photons at the LHC, one challenge is to distinguish scenarios with isolated photons from models leading to "photon jets". For instance, in the context of the 750 GeV diphoton excess, it was pointed out that a true diphoton resonance [Formula: see text] can be mimicked by a process of the form [Formula: see text], where S is a new scalar with a mass of 750 GeV and a is a light pseudoscalar decaying to two collinear photons. Photon jets can be distinguished from isolated photons by exploiting the fact that a large fraction of photons convert to an [Formula: see text] pair inside the inner detector. In this note, we quantify this discrimination power, and we study how the sensitivity of future searches differs for photon jets compared to isolated photons. We also investigate how our results depend on the lifetime of the particle(s) decaying to the photon jet. Finally, we discuss the extension to [Formula: see text], where there are no photons at all but the dark photon [Formula: see text] decays to [Formula: see text] pairs. Our results will be useful in future studies of the putative 750 GeV signal, but also more generally in any new physics search involving hard photons.

  13. Photons, photon jets and dark photons at 750 GeV and beyond

    International Nuclear Information System (INIS)

    Dasgupta, Basudeb; Kopp, Joachim

    2016-03-01

    In new physics searches involving photons at the LHC, one challenge is to distinguish scenarios with isolated photons from models leading to ''photon jets''. For instance, in the context of the 750 GeV diphoton excess, it was pointed out that a true diphoton resonance S → γγ can be mimicked by a process of the form pp → S → aa → 4γ, where S is a new scalar with a mass of 750 GeV and a is a light pseudoscalar decaying to two collinear photons. Photon jets can be distinguished from isolated photons by exploiting the fact that a large fraction of photons convert to an e + e - pair inside the inner detector. In this note, we quantify this discrimination power, and we study how the sensitivity of future searches differs for photon jets compared to isolated photons. We also investigate how our results depend on the lifetime of the particle(s) decaying to the photon jet. Finally, we discuss the extension to S → A'A' → e + e - e + e - , where there are no photons at all but the dark photon A' decays to e + e - pairs. Our results will be useful in future studies of the putative 750 GeV signal, but also more generally in any new physics search involving hard photons.

  14. Multi-photon entanglements

    International Nuclear Information System (INIS)

    Daniell, M.L.

    2000-09-01

    The motivation of this thesis was to create higher-order entanglements. The first experimental observation of a four-photon entanglement was presented in the experiment of this thesis. And the visibility of this entanglement was 0.79+-0.06, which is sufficient to make claims of the nonlocality of quantum mechanics. This therefore lays a foundation for experiments showing the nonlocality of teleportation, and the purification of entanglement. The work of this thesis brings together a lot of earlier work done by the Zeilinger Group, and lays a foundation for future experiments. Earlier experiments such as teleportation together with entanglement swapping, which are 'complete teleportation' in as much as the state teleported is entirely undefined, can be combined and re-done with this four-photon entanglement. This result would be the first demonstration of complete, nonlocal teleportation. Also this experiment can be slightly modified and used to perform the first experimental quantum purification of entanglement, which is of vital importance to the fields of quantum information, and also is interesting for fundamental experiments on entanglement. Another direct application of this experiment is to perform the first 'event-ready' testing of Bell's Inequality. Here the four-photon entanglement can be used as a source of entangled photons, whereby the photons have no common source. This would enable an even more stringent testing of Bells theorem. Finally this experiment can be used for the demonstration and investigation of many practical, directly applicable quantum information schemes. For instance quantum cryptography, error correction, and computing. (author)

  15. Nonlinear photonic quasicrystals

    International Nuclear Information System (INIS)

    Freedman, B.; Bartal, G.; Segev, M.; Lifshitz, R.; Christodoulides, D.; Fleischer, J.

    2005-01-01

    Full Text:Quasicrystals are structures with long-range order and no periodicity, whose unique structural and physical properties have intrigued scientists ever since their discovery and initial theoretical analysis more than two decades ago. The lack of periodicity excludes the use of well-established theoretical and experimental tools for the analysis of quasicrystals, including such notions as the Brillouin zone and Bloch theorem. Instead, the quasiperiodic atomic arrangement gives rise to unique properties such as a hierarchy of effective Brillouin (or Jones) zones, yielding a fractal-like band structure, and the existence of unique phason degrees of freedom. Generally, in atomic quasicrystals it is very difficult to directly observe the evolution of electronic wave-packets propagating through the structure, or the dynamics of the structure itself. Photonic quasicrystals, on the other hand, are macroscopic objects and hence their internal wave dynamics can be locally excited and directly imaged. Here, we employ optical induction to create 2D photonic quasicrystals, and explore wave transport phenomena in quasicrystals in ways that were impossible until now. We demonstrate linear tunneling-transport of light initiated at different crystal sites, and observe the formation of lattice solitons when the light is made sufficiently intense. We experiment with dynamical photonic quasicrystals, in which crystal sites interact with one another, and directly observe dislocation dynamics: creation, healing, and local structural rearrangement due to phason flips. Our experiments show that photonic quasicrystals are an excellent model system through which one can study the universal features of wave dynamics in quasiperiodic structures, that should apply not only to photonics, but also to other systems such as matter waves in quasiperiodic traps, generic pattern-forming systems as in parametrically-excited surface waves, liquid quasicrystals, as well as the more familiar

  16. Training options for countering nuclear smuggling

    International Nuclear Information System (INIS)

    Ball, D Y; Erickson, S A

    1999-01-01

    The burden of stopping a nuclear smuggling attempt at the border rests most heavily on the front-line customs inspector. He needs to know how to use the technological tools at his disposal, how to discern tell-tale anomalies in export documents and manifests, how to notice psychological signs of a smuggler's tension, and how to search anything that might hide nuclear material. This means that assistance in the counter-nuclear smuggling training of customs officers is one of the most critical areas of help that the United States can provide. This paper discusses the various modes of specialized training, both in the field and in courses, as well as the types of assistance that can be provided. Training for nuclear customs specialists, and supervisors and managers of nuclear smuggling detection systems is also important, and differs from front-line inspector training in several aspects. The limitations of training and technological tools such as expert centers that will overcome these limitations are also discussed. Training assistance planned by DOE/NN-43 to Russia within the Second Line of Defense program is discussed in the light of these options, and future possibilities for such training are projected

  17. Sexual revolution and counter-revolution.

    Science.gov (United States)

    Money, J

    1994-01-01

    Adolescents of today inherit the conflicting legacies of the sexual reformation of the 1960s and the counter-reformation of the 1980s/1990s. Sexual mores are influenced by a younger age of puberty than in earlier generations and by the availability of effective contraception and antibiotics to combat sexually transmitted diseases. In the era of acquired immune deficiency syndrome, however, absolutely safe sex cannot be guaranteed, only relative degrees of safety and risk. Masturbation may be one way of achieving safe sex. Advancing technology also allows greater equality of opportunity and economic emancipation for women, enabling men and women to share equally in the care of older infants and children, also influencing sexual roles. Sex education for adolescents is provided sporadically and inconsistently, being seen by opposing factions as either encouragement to early pregnancy or a means of preventing it. In particular, the images delivered by the mass media are blatantly contradictory, ranging from endorsement of teenage sexual expression to condemnation of abortion and teenage pregnancy. Cultural traditions have strong influences on the acceptability of early pregnancy and on family structure. Black American culture is based on the three-generational family as opposed to the white tradition of the nuclear, two-generational family. It is important to realize a social policy that will respect not only the sexual rights of young people, but also the sexual health of the community.

  18. The three-photon vertex

    International Nuclear Information System (INIS)

    Delbourgo, R.

    1976-01-01

    Owing to weak interactions, the three-photon vertex is non-zero. From gauge invariance and symmetry requirements, it is proved that the C = -1P = - 1 vertex amplitudes are at least of order q 7 in the limit of soft photon momentum q and that if any two photons are placed on mass shell the form factors vanish identically. (author)

  19. Optimization of photonic crystal cavities

    DEFF Research Database (Denmark)

    Wang, Fengwen; Sigmund, Ole

    2017-01-01

    We present optimization of photonic crystal cavities. The optimization problem is formulated to maximize the Purcell factor of a photonic crystal cavity. Both topology optimization and air-hole-based shape optimization are utilized for the design process. Numerical results demonstrate...... that the Purcell factor of the photonic crystal cavity can be significantly improved through optimization....

  20. The research on the failure regularity of GM counter tubes

    International Nuclear Information System (INIS)

    Li Jiyuan; Huai Guangli; Xie Bo; Zhang Hao

    2002-01-01

    The reliability of GM counter tubes should be described by useful time before failure-life and failure rate during life. A new method to study the failure regularity of GM counter tubes is advanced and adopted. The essential point of the method is that after the GM counter tubes of the instruments in use is tested, both the performance parameters and other information of the GM counter tubes and the instruments collected are recorded. Then database is created. Failure criterion is ascertained. The GM counter tubes are inspected to determine whether they are failure. Failure mode should be decided if the GM counter tubes failure. The GM counter tubes with the same useful year come together to make up a subsample. According to the relevant information, the number of the subsample is restored to the number of the sample that initially put into use. Then the number of failure sample is counted and at the same time the distribution of failure mode is got. The parameter m, γ, t 0 of Weibull distribution function are calculated with method of linear fit. Thus mean life, failure rate and other character values are obtained. Using this method, useful life and failure rate are determined. The conclusion is that the useful life is 18-20 years and the failure rate is 5 x 10 -6 and 4 x 10 -6 /h respectively during the course

  1. COUNTER-PUNISHMENT, COMMUNICATION AND COOPERATION AMONG PARTNERS

    Directory of Open Access Journals (Sweden)

    Giulia eAndrighetto

    2016-04-01

    Full Text Available We study how communication affects cooperation in an experimental public goods environment with punishment and counter-punishment opportunities. Participants interacted over thirty rounds in fixed groups with fixed identifiers that allowed them to trace other group members’ behavior over time. The two dimensions of communication we study are asking for a specific contribution level and having to express oneself when choosing to counter-punish. We conduct four experimental treatments, all involving a contribution stage, a punishment stage and a counter-punishment stage in each round. In the first treatment communication is not possible at any of the stages. The second treatment allows participants to ask for a contribution level at the punishment stage and in the third treatment participants are required to send a message if they decide to counter-punishment. The fourth combines the two communication channels of the second and third treatments. We find that the three treatments involving communication at any of the two relevant stages lead to significantly higher contributions than the baseline treatment. We find no difference between the three treatments with communication. We also relate our results to previous results from treatments without counter-punishment opportunities and do not find that the presence of counter-punishment leads to lower cooperation level. The overall pattern of results shows that given fixed identifiers the key factor is the presence of communication. Whenever communication is possible contributions and earnings are higher than when it is not, regardless of counter-punishment opportunities.

  2. Neuromorphic photonic networks using silicon photonic weight banks.

    Science.gov (United States)

    Tait, Alexander N; de Lima, Thomas Ferreira; Zhou, Ellen; Wu, Allie X; Nahmias, Mitchell A; Shastri, Bhavin J; Prucnal, Paul R

    2017-08-07

    Photonic systems for high-performance information processing have attracted renewed interest. Neuromorphic silicon photonics has the potential to integrate processing functions that vastly exceed the capabilities of electronics. We report first observations of a recurrent silicon photonic neural network, in which connections are configured by microring weight banks. A mathematical isomorphism between the silicon photonic circuit and a continuous neural network model is demonstrated through dynamical bifurcation analysis. Exploiting this isomorphism, a simulated 24-node silicon photonic neural network is programmed using "neural compiler" to solve a differential system emulation task. A 294-fold acceleration against a conventional benchmark is predicted. We also propose and derive power consumption analysis for modulator-class neurons that, as opposed to laser-class neurons, are compatible with silicon photonic platforms. At increased scale, Neuromorphic silicon photonics could access new regimes of ultrafast information processing for radio, control, and scientific computing.

  3. Countering the ‘Natural’ Organizational Self on Social Media

    DEFF Research Database (Denmark)

    Johansen, Trine Susanne

    2017-01-01

    , challenge and contradict organizational self-narration in light of market place skepticism and cynicism. The study identifies three strategies of counter-narrativizing (authenticity, legitimacy and irony) based on juxtaposing pairs of opposites. Moreover, it suggests counter-narration to be a natural......Using narrative as a theoretical and methodological lens, this study explores digital processes of organizational identity construction in the intersection between organization and market.The purpose is to understand the ways in which online interactions produce counter-narratives that contrast...

  4. Hardware support for collecting performance counters directly to memory

    Science.gov (United States)

    Gara, Alan; Salapura, Valentina; Wisniewski, Robert W.

    2012-09-25

    Hardware support for collecting performance counters directly to memory, in one aspect, may include a plurality of performance counters operable to collect one or more counts of one or more selected activities. A first storage element may be operable to store an address of a memory location. A second storage element may be operable to store a value indicating whether the hardware should begin copying. A state machine may be operable to detect the value in the second storage element and trigger hardware copying of data in selected one or more of the plurality of performance counters to the memory location whose address is stored in the first storage element.

  5. Numerical modelling of tissue-equivalent proportional counters

    International Nuclear Information System (INIS)

    Segur, P.; Colautti, P.

    1995-01-01

    In this paper a survey is given of the various numerical techniques employed to study the transport of ionising particles inside a TEPC. The first part is devoted to the description of the general concept of particle transport calculations. Thereafter, the different methods available to study transport phenomena and energy deposition in the sensitive volume and in counter walls are described. Finally, the basic ionisation mechanisms which may occur in a counter are described, and the non-equilibrium phenomena which play an important role mainly for counters that are to be used in measurements at the nanodosemeter level are studied. (author)

  6. Photorefractive Photonics 2017

    International Nuclear Information System (INIS)

    2017-01-01

    Preface This volume of Journal of Physics: Conference Series represents a selection of the contributions presented in the Photorefractive Photonics 2017 (PR17) conference which was held in Qingdao, Shandong, China from July 17 through July 20, 2017. The conference is the successor of the traditional Photorefractive (PR) Conference Series: the International Conference on Photorefractive Effects, Materials and Devices. The first PR Conference was held in Los Angeles, California, USA in 1987. After that, the PR Conference was held every two years around the world: Aussois, France (1989), Beverly, Massachusetts, USA (1991), Kiev, Ukraine (1993), Aspen Lodge, Colorado, USA (1995), Chiba, Japan (1997), Elsinore, Denmark (1999), Delevan, Wisconsin, USA (2001), Nice, France (2003), Sanya, Hainan, China (2005), Olympic Valley, California, USA (2007), Bad Honnef, Germany (2009), Ensenada, Mexico (2011), Winchester, UK (2013) and Villars, Switzerland (2015). The Conference was renamed to be Photorefractive Photonics Conference in 2015. The PR17 conference was organized by Nankai University, Qingdao University and Qingdao Society of Physics. The scientific topics of the PR17 conference include, but not limited to, wave mixing and its applications (T1), nonlinear light-matter interaction and its applications (T2), material engineering and photonic micro-structures (T3), photorefractive lattice photonics (T4), digital photorefractive photonics (T5), and novel photorefractive effects, materials and applications (T6). Note that both traditional topics such as photorefractive wave mixing and new topics such as energy photonics and nano/micro-structures based on photorefractive effects and materials are included, especially, basic issues such as the influence of pyroelectric effect on the photorefractive wave-mixing are considered, and much attention was paid to the development of new applications of photorefractive effects and materials, which reflect the current state of the art

  7. Physics with Photons in ATLAS

    CERN Multimedia

    CERN. Geneva

    2011-01-01

    The fine granularity ATLAS electromagnetic calorimeter provides a precise measurement of the photon energy and direction, as well as efficient rejection of background from fake photons, while the high precision inner detector allows also the reconstruction of photons that convert into electron-positron pairs.Isolated photons are measured using well-defined infrared-safe isolation criteria corrected for underlying event and the effects of additional proton-proton collisions. Differential cross sections for inclusive photons and diphotons are presented, and the spectrum of diphoton production is used to search for the Higgs boson in this decay channel.

  8. Few-photon optical diode

    OpenAIRE

    Roy, Dibyendu

    2010-01-01

    We propose a novel scheme of realizing an optical diode at the few-photon level. The system consists of a one-dimensional waveguide coupled asymmetrically to a two-level system. The two or multi-photon transport in this system is strongly correlated. We derive exactly the single and two-photon current and show that the two-photon current is asymmetric for the asymmetric coupling. Thus the system serves as an optical diode which allows transmission of photons in one direction much more efficie...

  9. Photon + jets at D0

    Energy Technology Data Exchange (ETDEWEB)

    Sonnenschein, Lars; /RWTH Aachen U.

    2009-06-01

    Photon plus jet production has been studied by the D0 experiment in Run II of the Fermilab Tevatron Collider at a centre of mass energy of {radical}s = 1.96 TeV. Measurements of the inclusive photon, inclusive photon plus jet, photon plus heavy flavour jet cross sections and double parton interactions in photon plus three jet events are presented. They are based on integrated luminosities between 0.4 fb{sup -1} and 1.0 fb{sup -1}. The results are compared to perturbative QCD calculations in various approximations.

  10. Helium-filled proportional counter and its operation mechanism at low temperatures

    CERN Document Server

    Isozumi, Y; Kishimoto, S

    2002-01-01

    The operation mechanism of helium-filled proportional counter (HFPC) at about 4.2 K is explained. Unstable behavior of HFPC is caused by releasing secondary-electron from the cathode by four kinds of active particles such as He sub n sup + , non-resonance photon from excited helium atom, non-resonance photon from He sub 2 sup * (A sup 1 Su sup +) and He sub 2 sup m (a sup 3 Su sup +). On experiments of HFPC behavior at low temperature, the following facts were observed; 1) main charge formation process in the electron avalanche is direct ionization by electron without Hornbeck-Molnar process. Accordingly, the gas amplification factor becomes small at low temperature. 2) Stable helium cation is He sub 2 sup + at room temperature, but cluster at low temperature. Large after-pulse is observed in output signal depends on cluster ion. The probability of secondary-electron emission decreased. The gas gain increased with increasing anode voltage. 3) By decreasing reaction rate of atom and molecule collision at low t...

  11. Photonic-powered cable assembly

    Science.gov (United States)

    Sanderson, Stephen N.; Appel, Titus James; Wrye, IV, Walter C.

    2013-01-22

    A photonic-cable assembly includes a power source cable connector ("PSCC") coupled to a power receive cable connector ("PRCC") via a fiber cable. The PSCC electrically connects to a first electronic device and houses a photonic power source and an optical data transmitter. The fiber cable includes an optical transmit data path coupled to the optical data transmitter, an optical power path coupled to the photonic power source, and an optical feedback path coupled to provide feedback control to the photonic power source. The PRCC electrically connects to a second electronic device and houses an optical data receiver coupled to the optical transmit data path, a feedback controller coupled to the optical feedback path to control the photonic power source, and a photonic power converter coupled to the optical power path to convert photonic energy received over the optical power path to electrical energy to power components of the PRCC.

  12. Essentials of photonics

    CERN Document Server

    Rogers, Alan; Baets, Roel

    2008-01-01

    Photons and ElectronsHistorical SketchThe Wave Nature of LightPolarizationThe Electromagnetic SpectrumEmission and Absorption ProcessesPhoton Statistics The Behaviour of Electrons LasersSummaryWave Properties of LightThe Electromagnetic SpectrumWave RepresentationElectromagnetic WavesReflection and RefractionTotal Internal ReflectionInterference of LightLight WaveguidingInterferometersDiffractionGaussian Beams and Stable Optical ResonatorsPolarization OpticsThe Polarization EllipseCrystal OpticsRetarding WaveplatesA Variable Waveplate: The Soleil-Babinet Compensator Polarizing PrismsLinear BirefringenceCircular BirefringenceElliptical BirefringencePractical Polarization EffectsPolarization AnalysisThe Form of the Jones MatricesLight and Matter Emission, Propagation, and Absorption ProcessesClassical Theory of Light Propagation in Uniform Dielectric Media Optical Dispersion Emission and Absorption of LightOptical Coherence and CorrelationIntroductionMeasure of Coherence Wiener-Khinchin TheoremDual-Beam Interfe...

  13. Nonlocal structures: bilocal photon

    International Nuclear Information System (INIS)

    Clapp, R.E.

    1980-01-01

    It is postulated that all particles and fields are built from a single primitive field, a massless fermion with a σ spin of one-half. Two helicities are embodied in a tau spin of one-half. The vacuum is an open Fermi sea whose height is a wave number kappa. Elementary particles are structures having the form of standing-wave systems floating on the vacuum sea. A bilocal photon starts with a function describing two primitive quanta with parallel σ spin and opposite tau spin. A centroid-time wave equation then couples-in and infinite set of orthogonal functions. The introduction of an operator Qlambda permits the reduction of the infinite secular determinant to finite six-by-six determinant. Solutions are obtained describing photons with right-handed and left-handed polarizations. Electric and magnetic field vectors satisfying the vacuum Maxwell equations, are obtained from a bilocal Hertz vector. (author)

  14. Quantum communication with photons

    International Nuclear Information System (INIS)

    Tittel, W.

    2005-01-01

    Full text: The discovery that transmission of information encoded into single quantum systems enables new forms of communication let to the emergence of the domain of quantum communication. During the last ten years, various key experiments based on photons as carrier of the quantum information have been realized. Today, quantum cryptography systems based on faint laser pulses can be purchased commercially, bi-partite entanglement has been distributed over long distances and has been used for quantum key distribution, and quantum purification, teleportation and entanglement swapping have been demonstrated. I will give a general introduction into this fascinating field and will review experimental achievements in the domain of quantum communication with discrete two-level quantum systems (qubits) encoded into photons. (author)

  15. Photonics an introduction

    CERN Document Server

    Reider, Georg A

    2016-01-01

    This book provides a comprehensive introduction into photonics, from the electrodynamic and quantum mechanic fundamentals to the level of photonic components and building blocks such as lasers, amplifiers, modulators, waveguides, and detectors. The book will serve both as textbook and as a reference work for the advanced student or scientist. Theoretical results are derived from basic principles with convenient, yet state-of-the-art mathematical tools, providing not only deeper understanding but also familiarization with formalisms used in the relevant technical literature and research articles. Among the subject matters treated are polarization optics, pulse and beam propagation, waveguides, light–matter interaction, stationary and transient behavior of lasers, semiconductor optics and lasers (including low-dimensional systems such as quantum wells), detector technology, photometry, and colorimetry. Nonlinear optics are elaborated comprehensively. The book is intended for both students of physics and elect...

  16. MCNP: Photon benchmark problems

    International Nuclear Information System (INIS)

    Whalen, D.J.; Hollowell, D.E.; Hendricks, J.S.

    1991-09-01

    The recent widespread, markedly increased use of radiation transport codes has produced greater user and institutional demand for assurance that such codes give correct results. Responding to these pressing requirements for code validation, the general purpose Monte Carlo transport code MCNP has been tested on six different photon problem families. MCNP was used to simulate these six sets numerically. Results for each were compared to the set's analytical or experimental data. MCNP successfully predicted the analytical or experimental results of all six families within the statistical uncertainty inherent in the Monte Carlo method. From this we conclude that MCNP can accurately model a broad spectrum of photon transport problems. 8 refs., 30 figs., 5 tabs

  17. Nonlinear Photonic Crystal Fibers

    DEFF Research Database (Denmark)

    Hansen, Kim Per

    2004-01-01

    Despite the general recession in the global economy and the collapse of the optical telecommunication market, research within specialty fibers is thriving. This is, more than anything else, due to the technology transition from standard all-glass fibers to photonic crystal fibers, which, instead....... The freedom to design the dispersion profile of the fibers is much larger and it is possible to create fibers, which support only a single spatial mode, regardless of wavelength. In comparison, the standard dispersion-shifted fibers are limited by a much lower index-contrast between the core and the cladding...... in 1996, and are today on their way to become the dominating technology within the specialty fiber field. Whether they will replace the standard fiber in the more traditional areas like telecommunication transmission, is not yet clear, but the nonlinear photonic crystal fibers are here to stay....

  18. Natural photonic crystals

    Energy Technology Data Exchange (ETDEWEB)

    Vigneron, Jean Pol, E-mail: jean-pol.vigneron@fundp.ac.be [Research Center in Physics of Matter and Radiation (PMR), University of Namur (FUNDP), rue de Bruxelles, 61, B-5000 Namur (Belgium); Simonis, Priscilla [Research Center in Physics of Matter and Radiation (PMR), University of Namur (FUNDP), rue de Bruxelles, 61, B-5000 Namur (Belgium)

    2012-10-15

    Photonic structures appeared in nature several hundred millions years ago. In the living world, color is used for communication and this important function strongly impacts the individual chances of survival as well as the chances to reproduce. This has a statistical influence on species populations. Therefore, because they are involved in evolution, natural color-generating structures are - from some point of view - highly optimized. In this short review, a survey is presented of the development of natural photonic crystal-type structures occurring in insects, spiders, birds, fishes and other marine animals, in plants and more, from the standpoint of light-waves propagation. One-, two-, and three-dimensional structures will be reviewed with selected examples.

  19. PHOTON: A user's manual

    International Nuclear Information System (INIS)

    Chapman, D.

    1988-01-01

    PHOTON has proven very useful in the development of the X17 superconducting wiggler beamline. Its use has determined the shielding required from the wiggler device to the very end of the beamline in the hutches and angiography section. Doses calculated by this program have been compared with experimental results from conventional bending magnet beamline with great success. In each case the program consistently overestimated the dose by factors ranging from 2 to 10. The reason for this overestimation is understood and was not refined further in the program in order to maintain some level of safety in the shielding calculations. PHOTON should prove useful in the design of any beamline. Its ability to calculate power deposited and spectra transmitted through nearly arbitrary beamline configurations as well as the scattered radiation doses through shielding walls make it a very powerful tool

  20. Natural photonic crystals

    International Nuclear Information System (INIS)

    Vigneron, Jean Pol; Simonis, Priscilla

    2012-01-01

    Photonic structures appeared in nature several hundred millions years ago. In the living world, color is used for communication and this important function strongly impacts the individual chances of survival as well as the chances to reproduce. This has a statistical influence on species populations. Therefore, because they are involved in evolution, natural color-generating structures are - from some point of view - highly optimized. In this short review, a survey is presented of the development of natural photonic crystal-type structures occurring in insects, spiders, birds, fishes and other marine animals, in plants and more, from the standpoint of light-waves propagation. One-, two-, and three-dimensional structures will be reviewed with selected examples.

  1. Photon flux determination for a precision measurement of the neutral pion lifetime

    Energy Technology Data Exchange (ETDEWEB)

    Teymurazyan, Aram [Univ. of Kentucky, Lexington, KY (United States)

    2008-01-01

    The Jefferson Lab Hall B PrimEx Collaboration is using tagged photons to perform a 1.4% level measurement of the absolute cross section for the photo-production of neutral pions in the Coulomb field of a nucleus as a test of Chiral Perturbation Theory. Such a high precision pushes the limits of the photon tagging technique in regards to the determination of the absolute photon flux. A multifaceted approach to this problem has included measuring the absolute tagging ratios with a Total Absorption Counter (TAC) as well as relative tagging ratios with a Pair Spectrometer (PS), and determining the rate of the tagging counters using multi-hit TDC's and a clock trigger. This enables the determination of the absolute tagged photon flux for the PrimEx experiment with uncertainty of ~ 1.0%, which is unprecedented. In view of the stringent constraints on the required precision of the photon flux for this experiment, periodicmeasurements of the pair production cross section were performed throughout the run. In these measurements, both the photon energy and flux were determined by the Jefferson Lab Hall B tagger, and the electron-positron pairs were swept by a magnetic field and detected in the new 1728 channel hybrid calorimeter (HyCal). The pair production crosssection was extracted with an uncertainty of ~ 2%, producing an agreement with theoretical calculations at the level of ~ 2%. This measurement provided a unique opportunity to verify the photon flux determination procedure for the PrimEx experiment.

  2. Counter-Chemical, Biological, Radiological, and Nuclear Operations

    National Research Council Canada - National Science Library

    2007-01-01

    ..., with little or no warning. Success in defending our nation, our military forces, and partners and allies depends on how effectively we apply air, space, and cyberspace power to counter this threat...

  3. Constant sensitivity circuit for solid state nuclear radiation counters

    International Nuclear Information System (INIS)

    Kronenberg, S.; Erkkila, B.

    1985-01-01

    The utilization of solid state counters in tactical radiological instruments for measuring intensities and doses of fallout gamma rays offers advantages over Geiger-Mueller (GM) counters such as a much wider dynamic range and low operating voltages. Their very small size is suitable for use in miniaturized equipment. However, these devices have a serious problem if used in a mixed, fast neutron/gamma environment such as is encountered e.g. in a battlefield where tactical nuclear weapons are used and neutrons, prompt, initial gammas and fallout gammas are killing factors of comparable importance. Exposure to fast neutrons reduces seriously their sensitivity. This makes the solid state counters at this time unacceptable for use in Army tactical surveillance equipment and in other applications where according to requirements the performance must not be impaired by exposure to fast neutrons. It seems to be possible to reduce to some extent this neutron generated damage by improving the crystal counters

  4. Current Over-the-Counter Medicine Label: Take a Look

    Science.gov (United States)

    ... This is to help protect consumers against possible criminal tampering. Drug products with tamper-evident packaging have ... Medicines Medicines in My Home (MIMH) Choosing the right over-the-counter medicine (OTCs) The Over-the- ...

  5. Expanded and combined uncertainty in measurements by GM counters

    International Nuclear Information System (INIS)

    Stankovic, K.; Arandjic, D.; Lazarevic, Dj.; Osmokrovic, P.

    2007-01-01

    This paper deals with possible ways of obtaining expanded and combined uncertainty in measurements for four types of GM counters with a same counter's tube, in cases when the contributors of these uncertainties are cosmic background radiation and induced overvoltage phenomena. Nowadays, as a consequence of electromagnetic radiation, the latter phenomenon is especially marked in urban environments. Based on experimental results obtained, it has been established that the uncertainties of an influenced random variable 'number of pulses from background radiation' and 'number of pulses induced by overvoltage' depend on the technological solution of the counter's reading system and contribute in different ways to the expanded and combined uncertainty in measurements of the applied types of GM counters. (author)

  6. Discrimination capability of avalanche counters detecting different ionizing particles

    International Nuclear Information System (INIS)

    Prete, G.; Viesti, G.; Padua Univ.

    1985-01-01

    The discrimination capability of avalanche counters to detect different ionizing particles has been studied using a 252 Cf source. Pulse height, pulse-height resolution and timing properties have been measured as a function of the reduced applied voltage for parallel-plate and parallel-grid avalanche counters. At the highest applied voltages, space charge effects shift the pulse-height signal of the avalanche counter away from being linearly proportional to the stopping power of the detected particles and cause the pulse-height resolution to deteriorate. To optimize the avalanche counter capability, without loss of time resolution, it appears better to operate the detector at voltages well below the breakdown threshold. Measurements with 32 S ions are also reported. (orig.)

  7. Retrofit designs for small bench-type blood cell counters.

    Science.gov (United States)

    Ferris, C D

    1991-01-01

    This paper describes several retrofit designs to correct operational problems associated with small bench-type blood cell counters. Replacement electronic circuits as well as modifications to the vacuum systems are discussed.

  8. New proportional counter assembly in Gliwice 14C laboratory

    International Nuclear Information System (INIS)

    Moscicki, W.; Zastawny, A.

    1977-01-01

    The design and parameters are described of a proportional counter for low level counting. The cathode tube 80 mm in diameter and 30 cm in length is made of pure copper. The anode is a tungsten wire 0.05 mm in diameter. The cathode tube is surrounded by a cylindrical ring container with mercury. The total volume of the counter is 1.5 l and it is filled with carbon dioxide. At a pressure of 1 at of CO 2 the counter background is 4.20+-0.05 cpm and contemporary 14 C net effect 10.22+-0.10 cpm; at a pressure of 2 at of CO 2 the background is 4.40+-0.05 cpm and the contemporary 14 C net effect 20.53+-10 cpm. The efficiency of the proportional counter is 88% in both cases. (J.B.)

  9. Illuminating WISPs with photons

    International Nuclear Information System (INIS)

    Arias, Paola

    2011-10-01

    Physics beyond the Standard Model naturally gives rise to very light and weakly interacting particles, dubbed WISPs (Weakly Interacting Slim Particles). A prime example is the axion, that has eluded experimental detection for more than thirty years. In this talk we review some of the strongly motivated candidates for such particles, the observational hints for them and the present status of searches with photon regeneration experiments, as well as possible future improvements. (orig.)

  10. Manipulating atoms with photons

    International Nuclear Information System (INIS)

    Cohen-Tannoudji, C.N.

    1998-01-01

    The article is a translation of the lecture delivered on the occasion of the 1997 Nobel Prize awarding ceremony. The physical mechanisms which allow manipulating of neutral atoms with laser photons are described. A remark is also made concerning several possible applications of ultra-cool atoms and streams of future research. The article is completed by Prof. Cohen-Tannoudji's autobiography. (Z.J.)

  11. Three-photon micromasers

    International Nuclear Information System (INIS)

    Obada, A.S.F.; Abu Sitta, A.M.M.; Yasin, O.M.

    1993-01-01

    A non-degenerate 3-photon micromaser is analyzed. A 4-level atom is taken and 3 models of the field are considered. The model is solved for the case of resonance and the master equation for the density matrix is obtained. Semi-analytical solutions are obtained under specified approximations. Three modes can exist depending on the time of interaction. (author). 10 refs, 2 figs

  12. Mass of the photon

    International Nuclear Information System (INIS)

    Goldhaber, A.S.; Nieto, M.M.

    1976-01-01

    Several experiments are discussed for which results are equivalent to the catching and weighing of a photon. It is noted that none of the experiments has proved the rest mass to be zero and that such a proof may be impossible. It is shown by such experiments that the rest mass is less than the limit of accuracy of the experiment. These limits have approached ever closer to zero, and the most recent values are exceedingly small

  13. Photonic Molecule Lasers Revisited

    Science.gov (United States)

    Gagnon, Denis; Dumont, Joey; Déziel, Jean-Luc; Dubé, Louis J.

    2014-05-01

    Photonic molecules (PMs) formed by coupling two or more optical resonators are ideal candidates for the fabrication of integrated microlasers, photonic molecule lasers. Whereas most calculations on PM lasers have been based on cold-cavity (passive) modes, i.e. quasi-bound states, a recently formulated steady-state ab initio laser theory (SALT) offers the possibility to take into account the spectral properties of the underlying gain transition, its position and linewidth, as well as incorporating an arbitrary pump profile. We will combine two theoretical approaches to characterize the lasing properties of PM lasers: for two-dimensional systems, the generalized Lorenz-Mie theory will obtain the resonant modes of the coupled molecules in an active medium described by SALT. Not only is then the theoretical description more complete, the use of an active medium provides additional parameters to control, engineer and harness the lasing properties of PM lasers for ultra-low threshold and directional single-mode emission. We will extend our recent study and present new results for a number of promising geometries. The authors acknowledge financial support from NSERC (Canada) and the CERC in Photonic Innovations of Y. Messaddeq.

  14. The photon structure function

    International Nuclear Information System (INIS)

    Berger, C.

    1984-01-01

    In principle we have to distinguish between three cases: In no-tag experiments, none of the outgoing leptons e + e - is detected. The photon flux is completely dominated by transversely polarized photons, which are practically on-mass-shell. In single-tag experiments, either the outgoing e - or e + is detected in a forward spectrometer. Sometimes the tagging information is only used for separating a multihadronic twophoton final state from e + e - annihilation states. On the other hand, the information from the forward detectors can be used to investigate the Q 2 behaviour of the cross-section. A combination of tagging on one side with antitagging on the other allows an easy interpretation of the results in terms of electron scattering off a real photon target. In double-tag experiments, both outgoing leptons are measured. In principle, the full kinematical structure of the process can be studied, but we are still a long way from starting to tackle this difficult task

  15. Slotted Photonic Crystal Sensors

    Science.gov (United States)

    Scullion, Mark G.; Krauss, Thomas F.; Di Falco, Andrea

    2013-01-01

    Optical biosensors are increasingly being considered for lab-on-a-chip applications due to their benefits such as small size, biocompatibility, passive behaviour and lack of the need for fluorescent labels. The light guiding mechanisms used by many of them results in poor overlap of the optical field with the target molecules, reducing the maximum sensitivity achievable. This review article presents a new platform for optical biosensors, namely slotted photonic crystals, which provide higher sensitivities due to their ability to confine, spatially and temporally, the optical mode peak within the analyte itself. Loss measurements showed values comparable to standard photonic crystals, confirming their ability to be used in real devices. A novel resonant coupler was designed, simulated, and experimentally tested, and was found to perform better than other solutions within the literature. Combining with cavities, microfluidics and biological functionalization allowed proof-of-principle demonstrations of protein binding to be carried out. Higher sensitivities were observed in smaller structures than possible with most competing devices reported in the literature. This body of work presents slotted photonic crystals as a realistic platform for complete on-chip biosensing; addressing key design, performance and application issues, whilst also opening up exciting new ideas for future study. PMID:23503295

  16. Nonlinear photonic metasurfaces

    Science.gov (United States)

    Li, Guixin; Zhang, Shuang; Zentgraf, Thomas

    2017-03-01

    Compared with conventional optical elements, 2D photonic metasurfaces, consisting of arrays of antennas with subwavelength thickness (the 'meta-atoms'), enable the manipulation of light-matter interactions on more compact platforms. The use of metasurfaces with spatially varying arrangements of meta-atoms that have subwavelength lateral resolution allows control of the polarization, phase and amplitude of light. Many exotic phenomena have been successfully demonstrated in linear optics; however, to meet the growing demand for the integration of more functionalities into a single optoelectronic circuit, the tailorable nonlinear optical properties of metasurfaces will also need to be exploited. In this Review, we discuss the design of nonlinear photonic metasurfaces — in particular, the criteria for choosing the materials and symmetries of the meta-atoms — for the realization of nonlinear optical chirality, nonlinear geometric Berry phase and nonlinear wavefront engineering. Finally, we survey the application of nonlinear photonic metasurfaces in optical switching and modulation, and we conclude with an outlook on their use for terahertz nonlinear optics and quantum information processing.

  17. Slotted Photonic Crystal Sensors

    Directory of Open Access Journals (Sweden)

    Andrea Di Falco

    2013-03-01

    Full Text Available Optical biosensors are increasingly being considered for lab-on-a-chip applications due to their benefits such as small size, biocompatibility, passive behaviour and lack of the need for fluorescent labels. The light guiding mechanisms used by many of them results in poor overlap of the optical field with the target molecules, reducing the maximum sensitivity achievable. This review article presents a new platform for optical biosensors, namely slotted photonic crystals, which provide higher sensitivities due to their ability to confine, spatially and temporally, the optical mode peak within the analyte itself. Loss measurements showed values comparable to standard photonic crystals, confirming their ability to be used in real devices. A novel resonant coupler was designed, simulated, and experimentally tested, and was found to perform better than other solutions within the literature. Combining with cavities, microfluidics and biological functionalization allowed proof-of-principle demonstrations of protein binding to be carried out. Higher sensitivities were observed in smaller structures than possible with most competing devices reported in the literature. This body of work presents slotted photonic crystals as a realistic platform for complete on-chip biosensing; addressing key design, performance and application issues, whilst also opening up exciting new ideas for future study.

  18. Photon-activation therapy

    International Nuclear Information System (INIS)

    Fairchild, R.G.; Bond, V.P.

    1982-01-01

    Photon Activation Therapy (PAT) is a technique in which radiation dose to tumor is enhanced via introduction of stable 127 I in the form of iodinated deoxyuridine (IdUrd). Stimulation of cytotoxic effects from IdUrd is accomplished by activation with external (or implanted) radiation sources. Thus, accumulations of this nucleoside in actively competing cellpools do not preclude therapy in so far as such tissues can be excluded from the radiation field. Calculations show that 5% replacement of thymidine (Tyd) in tumor DNA should enhance the biological effectiveness of a given photon radiotherapy dose by a factor of approx. 3. Proportionally higher gains would result from higher replacements of Tyd and IdUrd. In addition, biological response is enhanced by chemical sensitization with IdUrd. The data indicate that damage from photon activation as well as chemical sensitization does not repair. Thus, at low dose rates, a further increase in therapeutic gain should accrue as normal tissues are allowed to repair and regenerate. A samarium-145 source has been developed for PAT, with activating x-ray energies of from 38 to 45 keV. Favorable clinical results can be expected through the use of IdUrd and protracted irradiations with low energy x-rays. In particular, PAT may provide unique advantages at selected sites such as brain, or head and neck tumors

  19. PERUMUSAN STRATEGI PEMASARAN FRY COUNTER DENGAN PENDEKATAN MODEL AIDA

    OpenAIRE

    Andi Oktoriyana; Ujang Sumarwan; Hartoyo Hartoyo

    2014-01-01

    This research examined factors which are mentioned in various literatures that have influence on AIDA models to buy fry counter which are attention, interest, and desire. The model also influenced by perceived attributes, personal characteristics, and external factors. Furthermore, the analysis result become a basic for formulating the marketing strategy of fry counter as an innovative product. Analysis was carried out using Structural Equation Modeling. The data for this study were collected...

  20. Test of long scintillating counter prototypes for CDF-II

    International Nuclear Information System (INIS)

    Budagov, Yu.; Chirikov-Zorin, I.; Pukhov, O.; Incagli, M.; Leone, S.; Menzione, A.; Pauletta, G.; Tokar, S.

    2000-01-01

    New type long (up to 3 m) scintillating counter prototypes, developed for CDF-II, have been tested. The shift-spectrum fiber ribbons were used for light collection, and modern ultra compact photomultipliers R5600 were used for light detection. The efficiency for m.i.p. was excellent for all prototypes. The light yield from the far end of the counters was found to be more than 20 photoelectrons