Charge collection properties of heavily irradiated epitaxial silicon detectors

International Nuclear Information System (INIS)

Kramberger, G.; Cindro, V.; Dolenc, I.; Fretwurst, E.; Lindstroem, G.; Mandic, I.; Mikuz, M.; Zavrtanik, M.

2005-01-01

Detectors processed on epitaxial silicon seem to be a viable solution for the extreme radiation levels in the innermost layers of tracking detectors at upgraded LHC (SLHC). A set of epitaxial pad detectors of 50 and 75μm thicknesses (ρ=50Ωcm) was irradiated with 24GeV/c protons and reactor neutrons up to equivalent fluences of 10 16 cm -2 . Charge collection for minimum ionizing electrons from a 90 Sr source was measured using a charge sensitive preamplifier and a 25ns shaping circuit. The dependence of collected charge on annealing time and operation temperature was studied. Results were used to predict the performance of fine pitch pixel detectors proposed for SLHC

Charge collection properties of heavily irradiated epitaxial silicon detectors

Energy Technology Data Exchange (ETDEWEB)

Kramberger, G. [Institute Jozef Stefan, Jamova 39, SI-1111 Ljubljana (Slovenia)]. E-mail: Gregor.Kramberger@ijs.si; Cindro, V. [Institute Jozef Stefan, Jamova 39, SI-1111 Ljubljana (Slovenia); Dolenc, I. [Institute Jozef Stefan, Jamova 39, SI-1111 Ljubljana (Slovenia); Fretwurst, E. [University of Hamburg, Institut fuer Experimentalphysik, Luruper Chaussee 149, D-22761 Hamburg (Germany); Lindstroem, G. [University of Hamburg, Institut fuer Experimentalphysik, Luruper Chaussee 149, D-22761 Hamburg (Germany); Mandic, I. [Institute Jozef Stefan, Jamova 39, SI-1111 Ljubljana (Slovenia); Mikuz, M. [Institute Jozef Stefan, Jamova 39, SI-1111 Ljubljana (Slovenia); Zavrtanik, M. [Institute Jozef Stefan, Jamova 39, SI-1111 Ljubljana (Slovenia)

2005-12-01

Detectors processed on epitaxial silicon seem to be a viable solution for the extreme radiation levels in the innermost layers of tracking detectors at upgraded LHC (SLHC). A set of epitaxial pad detectors of 50 and 75{mu}m thicknesses ({rho}=50{omega}cm) was irradiated with 24GeV/c protons and reactor neutrons up to equivalent fluences of 10{sup 16}cm{sup -2}. Charge collection for minimum ionizing electrons from a {sup 90}Sr source was measured using a charge sensitive preamplifier and a 25ns shaping circuit. The dependence of collected charge on annealing time and operation temperature was studied. Results were used to predict the performance of fine pitch pixel detectors proposed for SLHC.

Heavy ion measurements by use of chemical detectors

International Nuclear Information System (INIS)

Huebner, K.; Erzgraeber, G.; Eichhorn, K.

1980-01-01

In order to test whether the threshold system polyvinyl alcohol/methyl organe/chloral hydrate/sodium tetraborate permits quantitative detection of individual particles, the chemical detector was irradiated at the JINR U-200 cyclotron with 4 He, 12 C, 18 O, 22 Ne ions having different LET. Irradiations were performed with detectors of four different borax concentrations (the chloral hydrate concentration being constant). The colour change dose Dsub(u) increases linearly with increasing borax concentration and at constant borax concentration with increasing LET. Hence it follows that the G value of dehydrochlorination decreases with increasing LET. Fluence ranges measurable with detectors of different composition are given for the heavy ions studied. (author)

Charge collection in Si detectors irradiated in situ at superfluid helium temperature

Energy Technology Data Exchange (ETDEWEB)

Verbitskaya, Elena, E-mail: elena.verbitskaya@cern.ch [Ioffe Institute, 26 Politekhnicheskaya str., St. Petersburg 194021 (Russian Federation); Eremin, Vladimir; Zabrodskii, Andrei [Ioffe Institute, 26 Politekhnicheskaya str., St. Petersburg 194021 (Russian Federation); Dehning, Bernd; Kurfürst, Christoph; Sapinski, Mariusz; Bartosik, Marcin R. [CERN, CH-1211, Geneva 23 (Switzerland); Egorov, Nicolai [Research Institute of Material Science and Technology, 4 Passage 4806, Moscow, Zelenograd 124460 (Russian Federation); Härkönen, Jaakko [Helsinki Institute of Physics, P.O.Box 64 (Gustaf Hallströmin katu 2) FI-00014 University of Helsinki (Finland)

2015-10-01

Silicon and diamond detectors operated in a superfluid helium bath are currently being considered for the upgrade of the LHC beam loss monitoring system. The detectors would be installed in immediate proximity of the superconducting coils of the triplet magnets. We present here the results of the in situ irradiation test for silicon detectors using 23 GeV protons while keeping the detectors at a temperature of 1.9 K. Red laser (630 nm) Transient Current Technique and DC current measurements were used to study the pulse response and collected charge for silicon detectors irradiated to a maximum radiation fluence of 1×10{sup 16} p/cm{sup 2}. The dependence between collected charge and irradiation fluence was parameterized using the Hecht equation and assumption of a uniform electric field distribution. The collected charge was found to degrade with particle fluence for both bias polarities. We observed that the main factor responsible for this degradation was related to trapping of holes on the donor-type radiation-induced defects. In contrast to expectations, along with formation of donors, acceptor-type defects (electron traps) are introduced into the silicon bulk. This suggests that the current models describing charge collection in irradiated silicon detectors require an extension for taking into account trapping at low temperatures with a contribution of shallow levels. New in situ irradiation tests are needed and planned now to extend statistics of the results and gain a deeper insight into the physics of low temperature detector operation in harsh radiation environment. - Highlights: • Si detectors irradiated in situ at 1.9 K by 23 GeV protons are further studied. • Trapping parameters are derived from the fits of collected charge vs. fluence data. • Acceptor-type defects are likely to be induced along with donor-type ones. • Trapping of holes has a dominating effect on the collected charge degradation. • New tests are planned to gain deeper insight

Response of Superheated Droplet Detector (SDD) and Bubble Detector (BD) to interrupted irradiations

Energy Technology Data Exchange (ETDEWEB)

Mondal, Prasanna Kumar, E-mail: prasanna_ind_82@yahoo.com; Sarkar, Rupa, E-mail: sarkar_rupa2003@yahoo.com; Chatterjee, Barun Kumar, E-mail: barun_k_chatterjee@yahoo.com

2017-06-11

Superheated droplet detectors (SDD) and bubble detectors (BD) are suspensions of micron-sized superheated liquid droplets in inert medium. The metastable droplets can vaporise upon interaction with ionising radiation generating visible bubbles. In this work, we investigated the response of SDD and BD to interrupted neutron irradiations. We observed that the droplet vaporisation rates for SDD and BD are different in nature. The unusual increase in droplet vaporisation rate observed when the SDD is exposed to neutrons after few minutes of radiation-off period is absent for BD. - Highlights: • Superheated droplet detectors (SDD) and bubble detectors (BD) are suspensions of superheated liquid droplets in inert medium. • The bubble nucleation in superheated droplets can be induced by ionising radiation. • The droplet vaporisation rate for SDD is non-monotonic when it is irradiated periodically to neutrons. • For BD the droplet vaporisation rate decrease monotonically when it is irradiated periodically to neutrons.

Study of charge transport in silicon detectors: Non-irradiated and irradiated

International Nuclear Information System (INIS)

Leroy, C.; Roy, P.; Casse, G.; Glaser, M.; Grigoriev, E.; Lemeilleur, F.

1999-01-01

The electrical characteristics of silicon detectors (standard planar float zone and MESA detectors) as a function of the particle fluence can be extracted by the application of a model describing the transport of charge carriers generated in the detectors by ionizing particles. The current pulse response induced by α and β particles in non-irradiated detectors and detectors irradiated up to fluences PHI ∼ 3 · 10 14 particles/cm 2 is reproduced via this model: i) by adding a small n-type region 15 μm deep on the p + side for the detectors at fluences beyond the n to p-type inversion and ii) for the MESA detectors, by considering one additional dead layer of 14 μm (observed experimentally) on each side of the detector, and introducing a second (delayed) component to the current pulse response. For both types of detectors, the model gives mobilities decreasing linearily up to fluences of about 5·10 13 particles/cm 2 and converging, beyond, to saturation values of about 1050 cm 2 /Vs and 450 cm 2 /Vs for electrons and holes, respectively. At a fluence PHI ∼ 10 14 particles/cm 2 (corresponding to about ten years of operation at the CERN-LHC), charge collection deficits of about 14% for β particles, 25% for α particles incident on the front and 35% for α particles incident on the back of the detector are found for both type of detectors

Dose Response of Alanine Detectors Irradiated with Carbon Ion Beams

DEFF Research Database (Denmark)

Herrmann, Rochus; Jäkel, Oliver; Palmans, Hugo

2011-01-01

Purpose: The dose response of the alanine detector shows a dependence on particle energy and type, when irradiated with ion beams. The purpose of this study is to investigate the response behaviour of the alanine detector in clinical carbon ion beams and compare the results with model predictions......-dose curves deviate from predictions in the peak region, most pronounced at the distal edge of the peak. Conclusions: The used model and its implementation show a good overall agreement for quasi mono energetic measurements. Deviations in depth-dose measurements are mainly attributed to uncertainties...

Tracking with heavily irradiated silicon detectors operated at cryogenic temperatures

International Nuclear Information System (INIS)

Casagrande, L.; Barnett, B.M.; Bartalina, P.

1999-01-01

In this work, the authors show that a heavily irradiated double-sided silicon microstrip detector recovers its performance when operated at cryogenic temperatures. A DELPHI microstrip detector, irradiated to a fluence of ∼4 x 10 14 p/cm 2 , no longer operational at room temperature, cannot be distinguished from a non-irradiated one when operated at T < 120 K. Besides confirming the previously observed Lazarus effect in single diodes, these results establish, for the first time, the possibility of using standard silicon detectors for tracking applications in extremely demanding radiation environments

Aging measurements on triple-GEM detectors operated with $CF_{4}$- based gas mixtures

CERN Document Server

Alfonsi, M; Bencivenni, G; Bonivento, W; Cardini, A; Lener, M P; Murtas, F; Pinci, D; Raspino, D; Saitta, B; De Simone, P

2004-01-01

We present the results of a global irradiation test of full size triple-GEM detectors operated with CF/sub 4/-based gas mixtures. This study has been performed in the framework of an R&D activity on detectors for the innermost region of the first muon station of the LHCb experiment. The prototypes have been irradiated at the Calliope facility of the ENEA-Casaccia with a high intensity 1.25 MeV gamma from a /sup 60/Co source. After the irradiation test the detectors performances have been measured with X-rays and with a 3 GeV pion beam at CERN. A SEM analysis on several samples of the detectors has been performed to complete the understanding of the physical processes occurring in the GEM detector during the strong irradiation.

Aging measurements on triple-GEM detectors operated with $CF_{4}$-based gas mixtures

CERN Document Server

Alfonsi, M; De Simone, P; Murtas, F; Poli Lener, M P; Bonivento, W; Cardini, A; Raspino, D; Saitta, B; Pinci, D; Baccaro, S; 10.1016/j.nuclphysbps.2005.03.054

2006-01-01

We present the results of a global irradiation test of full size triple-GEM detectors operated with CF/sub 4/-based gas mixtures. This study has been performed in the framework of an R&D activity on detectors for the innermost region of the first muon station of the LHCb experiment. The prototypes have been irradiated at the Calliope facility of the ENEA-Casaccia with a high intensity 1.25 MeV detectors performances have been measured with X-rays and with a 3 Ge V pion beam at CERN. A SEM analysis on several samples of the detectors has been performed to complete the understanding of the physical processes occurring in a GEM detector during a strong irradiation.

Pulse laser irradiation into superconducting MgB2 detector

International Nuclear Information System (INIS)

Fujiwara, Daisuke; Miki, Shigehito; Satoh, Kazuo; Yotsuya, Tsutomu; Shimakage, Hisashi; Wang, Zhen; Okayasu, Satoru; Katagiri, Masaki; Machida, Masahiko; Kato, Masaru; Ishida, Takekazu

2005-01-01

We performed 20-ps pulse laser irradiation experiments on a MgB 2 neutron detector to know a thermal-relaxation process for designing a MgB 2 neutron detector. The membrane-type structured MgB 2 device was fabricated to minimize the heat capacity of sensing part of a detector as well as to enhance its sensitivity. We successfully observed a thermal-relaxation signal resulting from pulse laser irradiation by developing a detection circuit. The response time was faster than 1 μs, meaning that the detector would be capable of counting neutrons at a rate of more than 10 6 events per second

Proton Irradiation of CVD Diamond Detectors for High Luminosity Experiments at the LHC

CERN Document Server

Meier, D; Bauer, C; Berdermann, E; Bergonzo, P; Bogani, F; Borchi, E; Bruzzi, Mara; Colledani, C; Conway, J; Dabrowski, W; Delpierre, P A; Deneuville, A; Dulinski, W; van Eijk, B; Fallou, A; Foulon, F; Friedl, M; Gan, K K; Gheeraert, E; Grigoriev, E A; Hallewell, G D; Hall-Wilton, R; Han, S; Hartjes, F G; Hrubec, Josef; Husson, D; Jany, C; Kagan, H; Kania, D R; Kaplon, J; Kass, R; Knöpfle, K T; Krammer, Manfred; Manfredi, P F; Marshall, R D; Mishina, M; Le Normand, F; Pan, L S; Palmieri, V G; Pernegger, H; Pernicka, Manfred; Peitz, A; Pirollo, S; Pretzl, Klaus P; Re, V; Riester, J L; Roe, S; Roff, D G; Rudge, A; Schnetzer, S R; Sciortino, S; Speziali, V; Stelzer, H; Stone, R; Tapper, R J; Tesarek, R J; Thomson, G B; Trawick, M L; Trischuk, W; Turchetta, R; Walsh, A M; Wedenig, R; Weilhammer, Peter; Ziock, H J; Zöller, M

1999-01-01

CVD diamond shows promising properties for use as a position sensitive detector for experiments in the highest radiation areas at the Large Hadron Collider. In order to study the radiation hardn ess of diamond we exposed CVD diamond detector samples to 24~GeV/$c$ and 500~MeV protons up to a fluence of $5\\times 10^{15}~p/{\\rm cm^2}$. We measured the charge collection distance, the ave rage distance electron hole pairs move apart in an external electric field, and leakage currents before, during, and after irradiation. The charge collection distance remains unchanged up to $1\\ times 10^{15}~p/{\\rm cm^2}$ and decreases by $\\approx$40~\\% at $5\\times 10^{15}~p/{\\rm cm^2}$. Leakage currents of diamond samples were below 1~pA before and after irradiation. The particle indu ced currents during irradiation correlate well with the proton flux. In contrast to diamond, a silicon diode, which was irradiated for comparison, shows the known large increase in leakage curren t. We conclude that CVD diamond detectors are radia...

Response of a BGO detector to photon and neutron sources simulations and measurements

CERN Document Server

Vincke, H H; Fabjan, Christian Wolfgang; Otto, T

2002-01-01

In this paper Monte Carlo simulations (FLUKA) and measurements of the response of a BGO detector are reported. %For the measurements different radioactive sources were used to irradiate the BGO crystal. For the measurements three low-energy photon emitters $\\left({}^{60}\\rm{Co},\\right.$ ${}^{54}\\rm{Mn},$ $\\left. {}^{137}\\rm{Cs}\\right)$ were used to irradiate the BGO from various distances and angles. The neutron response was measured with an Am--Be neutron source. Simulations of the experimental irradiations were carried out. Our study can also be considered as a benchmark for FLUKA in terms of its reliability to predict the detector response of a BGO scintillator.

Operation of heavily irradiated silicon detectors in non-depletion mode

International Nuclear Information System (INIS)

Verbitskaya, E.; Eremin, V.; Ilyashenko, I.; Li, Z.; Haerkoenen, J.; Tuovinen, E.; Luukka, P.

2006-01-01

The non-depletion detector operation mode has generally been disregarded as an option in high-energy physics experiments. In this paper, the non-depletion operation is examined by detailed analysis of the electric field distribution and the current pulse response of heavily irradiated silicon (Si) detectors. The previously reported model of double junction in heavily irradiated Si detector is further developed and a simulation of the current pulse response has been performed. It is shown that detectors can operate in a non-depletion mode due to the fact that the value of the electric field in a non-depleted region is high enough for efficient carrier drift. This electric field originates from the current flow through the detector and a consequent drop of the potential across high-resistivity bulk of a non-depleted region. It is anticipated that the electric field in a non-depleted region, which is still electrically neutral, increases with fluence that improves the non-depleted detector operation. Consideration of the electric field in a non-depleted region allows the explanation of the recorded double-peak current pulse shape of heavily irradiated Si detectors and definition of the requirements for the detector operational conditions. Detailed reconstruction of the electric field distribution gives new information on radiation effects in Si detectors

Evaluation of Irradiated Barrel Detector Modules for the Upgrade of the CMS Pixel Detector

CERN Document Server

Sibille, Jennifer Ann

2013-01-01

Prototype detector modules comprising sensors and the new readout chips were assembled and irradiated with protons at the CERN PS, and readout chips without sensors have been irradiated with protons at the Karls...

Simulation of medical irradiation and X-ray detector signals

Energy Technology Data Exchange (ETDEWEB)

Kreisler, Bjoern

2010-02-08

This thesis aims for an improved understanding of medical irradiation. Two major parts are investigated: the beam shaping components of a medical linear accelerator, i.e. the source of the radiation, and the signal generation inside semiconductor sensors, i.e. the detection of the radiation. The direct measurement of the spatial and spectral particle distribution in the irradiation beam is not possible with state of the art detectors due to the high particle flux. The development of new advanced detectors is the goal of the first part of this thesis. The focus is set on the signal generation inside the sensor volume of a semiconductor detector. Incoming particles interact with the sensor material and generate clouds of electron hole pairs. These pairs get separated by an applied bias voltage. The motion of the charge clouds is simulated with a finite element programme taking into account the drift and diffusion. Mirror charges are induced on the electrodes which move due to the motion of the charge cloud. The motion of the induced mirror charges leads to the signal that is detected. The transient calculation of the signals is based on Ramo's theorem. The efficient adjoint formulation of the induction solution is adjusted to doped materials, as for example the electric bias field and hence the motion of the charge cloud is changing with the doping level. The effect of the doping of the material on the signal shape is shown together with influences of different voltages and pixel geometries. Smaller pixels and higher bias voltages can lead to shorter signals which is preferable for high flux measurements. Possible count rate improvements are limited by electric break through, high dark current across the sensor layer and charge sharing. Another option to shorten the signals is the use of steering grid electrodes which modify the electric and the weighting field. This results in shorter signals and thus in a higher possible rate. The detailed Monte

Simulation of medical irradiation and X-ray detector signals

International Nuclear Information System (INIS)

Kreisler, Bjoern

2010-01-01

This thesis aims for an improved understanding of medical irradiation. Two major parts are investigated: the beam shaping components of a medical linear accelerator, i.e. the source of the radiation, and the signal generation inside semiconductor sensors, i.e. the detection of the radiation. The direct measurement of the spatial and spectral particle distribution in the irradiation beam is not possible with state of the art detectors due to the high particle flux. The development of new advanced detectors is the goal of the first part of this thesis. The focus is set on the signal generation inside the sensor volume of a semiconductor detector. Incoming particles interact with the sensor material and generate clouds of electron hole pairs. These pairs get separated by an applied bias voltage. The motion of the charge clouds is simulated with a finite element programme taking into account the drift and diffusion. Mirror charges are induced on the electrodes which move due to the motion of the charge cloud. The motion of the induced mirror charges leads to the signal that is detected. The transient calculation of the signals is based on Ramo's theorem. The efficient adjoint formulation of the induction solution is adjusted to doped materials, as for example the electric bias field and hence the motion of the charge cloud is changing with the doping level. The effect of the doping of the material on the signal shape is shown together with influences of different voltages and pixel geometries. Smaller pixels and higher bias voltages can lead to shorter signals which is preferable for high flux measurements. Possible count rate improvements are limited by electric break through, high dark current across the sensor layer and charge sharing. Another option to shorten the signals is the use of steering grid electrodes which modify the electric and the weighting field. This results in shorter signals and thus in a higher possible rate. The detailed Monte-Carlo simulation of

Signal generation in highly irradiated silicon microstrip detectors for the ATLAS experiment

International Nuclear Information System (INIS)

Ruggiero, Gennaro

2003-01-01

Silicon detectors are the most diffused tracking devices in High Energy Physics (HEP). The reason of such success can be found in the characteristics of the material together with the existing advanced technology for the fabrication of these devices. Nevertheless in many modem HEP experiments the observation of vary rare events require data taking at high luminosity with a consequent extremely intense hadron radiation field that damages the silicon and degrades the performance of these devices. In this thesis work a detailed study of the signal generation in microstrip detectors has been produced with a special care for the ATLAS semiconductor tracker geometry. This has required a development of an appropriate setup to perform measurements with Transient Current/ Charge Technique. This has allowed studying the evolution of the signal in several microstrips detector samples irradiated at fluences covering the range expected in the ATLAS Semiconductor Tracker. For a better understanding of these measurements a powerful software package that simulates the signal generation in these devices has been developed. Moreover in this thesis it has been also shown that the degradation due to radiation in silicon detectors can be strongly reduced if the data taking is done with detectors operated at 130 K. This makes low temperature operation that benefits of the recovery of the charge collection efficiency in highly irradiated silicon detectors (also known as Lazarus effect) an optimal option for future high luminosity experiments. (author)

Proton irradiation of CVD diamond detectors for high-luminosity experiments at the LHC

Science.gov (United States)

Meier, D.; Adam, W.; Bauer, C.; Berdermann, E.; Bergonzo, P.; Bogani, F.; Borchi, E.; Bruzzi, M.; Colledani, C.; Conway, J.; Dabrowski, W.; Delpierre, P.; Deneuville, A.; Dulinski, W.; van Eijk, B.; Fallou, A.; Foulon, F.; Friedl, M.; Jany, C.; Gan, K. K.; Gheeraert, E.; Grigoriev, E.; Hallewell, G.; Hall-Wilton, R.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kania, D.; Kaplon, J.; Kass, R.; Knöpfle, K. T.; Krammer, M.; Manfredi, P. F.; Marshall, R. D.; Mishina, M.; Le Normand, F.; Pan, L. S.; Palmieri, V. G.; Pernegger, H.; Pernicka, M.; Peitz, A.; Pirollo, S.; Pretzl, K.; Re, V.; Riester, J. L.; Roe, S.; Roff, D.; Rudge, A.; Schnetzer, S.; Sciortino, S.; Speziali, V.; Stelzer, H.; Stone, R.; Tapper, R. J.; Tesarek, R.; Thomson, G. B.; Trawick, M.; Trischuk, W.; Turchetta, R.; Walsh, A. M.; Wedenig, R.; Weilhammer, P.; Ziock, H.; Zoeller, M.; RD42 Collaboration

1999-04-01

CVD diamond shows promising properties for use as a position-sensitive detector for experiments in the highest radiation areas at the Large Hadron Collider. In order to study the radiation hardness of diamond we exposed CVD diamond detector samples to 24 Gev/ c and 500 Mev protons up to a fluence of 5×10 15 p/cm 2. We measured the charge collection distance, the average distance electron-hole pairs move apart in an external electric field, and leakage currents before, during, and after irradiation. The charge collection distance remains unchanged up to 1×10 15 p/cm 2 and decreases by ≈40% at 5×10 15 p/cm 2. Leakage currents of diamond samples were below 1 pA before and after irradiation. The particle-induced currents during irradiation correlate well with the proton flux. In contrast to diamond, a silicon diode, which was irradiated for comparison, shows the known large increase in leakage current. We conclude that CVD diamond detectors are radiation hard to 24 GeV/ c and 500 MeV protons up to at least 1×10 15p/cm 2 without signal loss.

Proton irradiation of CVD diamond detectors for high-luminosity experiments at the LHC

International Nuclear Information System (INIS)

Meier, D.; Adam, W.; Bauer, C.; Berdermann, E.; Bergonzo, P.; Bogani, F.; Borchi, E.; Bruzzi, M.; Colledani, C.; Conway, J.; Dabrowski, W.; Delpierre, P.; Deneuville, A.; Dulinski, W.; Eijk, B. van; Fallou, A.; Foulon, F.; Friedl, M.; Jany, C.; Gan, K.K.; Gheeraert, E.; Grigoriev, E.; Hallewell, G.; Hall-Wilton, R.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kania, D.; Kaplon, J.; Kass, R.; Knoepfle, K.T.; Krammer, M.; Manfredi, P.F.; Marshall, R.D.; Mishina, M.; Le Normand, F.; Pan, L.S.; Palmieri, V.G.; Pernegger, H.; Pernicka, M.; Peitz, A.; Pirollo, S.; Pretzl, K.; Re, V.; Riester, J.L.; Roe, S.; Roff, D.; Rudge, A.; Schnetzer, S.; Sciortino, S.; Speziali, V.; Stelzer, H.; Stone, R.; Tapper, R.J.; Tesarek, R.; Thomson, G.B.; Trawick, M.; Trischuk, W.; Turchetta, R.; Walsh, A.M.; Wedenig, R.; Weilhammer, P.; Ziock, H.; Zoeller, M.

1999-01-01

CVD diamond shows promising properties for use as a position-sensitive detector for experiments in the highest radiation areas at the Large Hadron Collider. In order to study the radiation hardness of diamond we exposed CVD diamond detector samples to 24 Gev/c and 500 Mev protons up to a fluence of 5x10 15 p/cm 2 . We measured the charge collection distance, the average distance electron-hole pairs move apart in an external electric field, and leakage currents before, during, and after irradiation. The charge collection distance remains unchanged up to 1x10 15 p/cm 2 and decreases by ∼40% at 5x10 15 p/cm 2 . Leakage currents of diamond samples were below 1 pA before and after irradiation. The particle-induced currents during irradiation correlate well with the proton flux. In contrast to diamond, a silicon diode, which was irradiated for comparison, shows the known large increase in leakage current. We conclude that CVD diamond detectors are radiation hard to 24 GeV/c and 500 MeV protons up to at least 1x10 15 p/cm 2 without signal loss

ASTRO-H CdTe detectors proton irradiation at PIF

International Nuclear Information System (INIS)

Limousin, O.; Renaud, D.; Horeau, B.; Dubos, S.; Laurent, P.; Lebrun, F.; Chipaux, R.; Boatella Polo, C.; Marcinkowski, R.; Kawaharada, M.; Watanabe, S.; Ohta, M.; Sato, G.; Takahashi, T.

2015-01-01

Asbstract: The French Atomic Energy Commission (CEA), with the support of the European Space Agency (ESA), is partner of the Soft Gamma-Ray Detector (SGD) and the Hard X-ray Imager (HXI) onboard the 6th Japanese X-ray scientific satellite ASTRO-H (JAXA) initiated by the Institute of Space and Astronautical Science (ISAS). Both scientific instruments, one hosting a series of Compton Gamma Cameras and the other being a focal plane of a grazing incidence mirror telescope in the hard X-ray domain, are equipped with Cadmium Telluride based detectors. ASTRO-H will be operated in a Low Earth Orbit with a 31° inclination at ~550 km altitude, thus passing daily through the South Atlantic Anomaly radiation belt, a specially harsh environment where the detectors are suffering the effect of the interaction with trapped high energy protons. As CdTe detector performance might be affected by the irradiation, we investigate the effect of the accumulated proton fluence on their spectral response. To do so, we have characterized and irradiated representative samples of SGD and HXI detector under different conditions. The detectors in question, from ACRORAD, are single-pixels having a size of 2 mm by 2 mm and 750 µm thick. The Schottky contact is either made of an Indium or Aluminum for SGD and HXI respectively. We ran the irradiation test campaign at the Proton Irradiation Facility (PIF) at PSI, and ESA approved equipment to evaluate the radiation hardness of flight hardware. We simulated the proton flux expected on the sensors over the entire mission, and secondary neutrons flux due to primary proton interactions into the surrounding BGO active shielding. We eventually characterized the detector response evolution, emphasizing each detector spectral response as well as its stability by studying the so-called Polarization effect. The latter is provoking a spectral response degradation against time as a charge accumulation process occurs in Schottky type CdTe sensors. In this paper

Self-Powered Neutron Detector Calibration Using a Large Vertical Irradiation Hole of HANARO

Directory of Open Access Journals (Sweden)

Kim Myong-Seop

2018-01-01

Full Text Available A calibration technology of the self-powered neutron detectors (SPNDs using a large vertical irradiation hole of HANARO is developed. The 40 Rh-SPNDs are installed on the polycarbonate plastic support, and the gold wires with the same length as the effective length of the rhodium emitter of the SPND are also installed to measure the neutron flux on the SPND. They are irradiated at a low reactor power, and the SPND current is measured using the pico-ammeter. The external gamma-rays which affect the SPND current response are analyzed using the Monte Carlo simulation for various irradiation conditions in HANARO. It is confirmed that the effect of the external gamma-rays to the SPND current is dependent on the reactor characteristics, and that it is affected by materials around the detector. The current signals due to the external gamma-rays can be either positive or negative, in that the net flow of the current may be either in the same or the opposite direction as the neutron-induced current by the rhodium emitter. From the above procedure, the effective calibration methodology of multiple SPNDs using the large hole of HANARO is developed. It could be useful for the calibration experiment of the neutron detectors in the research reactors.

Self-Powered Neutron Detector Calibration Using a Large Vertical Irradiation Hole of HANARO

Science.gov (United States)

Kim, Myong-Seop; Park, Byung-Gun; Kang, Gi-Doo

2018-01-01

A calibration technology of the self-powered neutron detectors (SPNDs) using a large vertical irradiation hole of HANARO is developed. The 40 Rh-SPNDs are installed on the polycarbonate plastic support, and the gold wires with the same length as the effective length of the rhodium emitter of the SPND are also installed to measure the neutron flux on the SPND. They are irradiated at a low reactor power, and the SPND current is measured using the pico-ammeter. The external gamma-rays which affect the SPND current response are analyzed using the Monte Carlo simulation for various irradiation conditions in HANARO. It is confirmed that the effect of the external gamma-rays to the SPND current is dependent on the reactor characteristics, and that it is affected by materials around the detector. The current signals due to the external gamma-rays can be either positive or negative, in that the net flow of the current may be either in the same or the opposite direction as the neutron-induced current by the rhodium emitter. From the above procedure, the effective calibration methodology of multiple SPNDs using the large hole of HANARO is developed. It could be useful for the calibration experiment of the neutron detectors in the research reactors.

Multilayer detector for skin absorbed dose measuring

International Nuclear Information System (INIS)

Osanov, D.P.; Panova, V.P.; Shaks, A.I.

1985-01-01

A method for skin dosimetry based on utilization of multilayer detectors and permitting to estimate distribution of absorbed dose by skin depth is described. The detector represents a set of thin sensitive elements separated by tissue-equivalent absorbers. Quantitative evaluation and forecasting the degree of radiation injury of skin are determined by the formula based on determination of the probability of the fact that cells are not destroyed and they can divide further on. The given method ensures a possibility of quantitative evaluation of radiobiological effect and forecasting clinical consequences of skin irradiation by results of corresponding measurements of dose by means of the miultilayer detector

NEUTRON SPECTRUM MEASUREMENTS USING MULTIPLE THRESHOLD DETECTORS

Energy Technology Data Exchange (ETDEWEB)

Gerken, William W.; Duffey, Dick

1963-11-15

From American Nuclear Society Meeting, New York, Nov. 1963. The use of threshold detectors, which simultaneously undergo reactions with thermal neutrons and two or more fast neutron threshold reactions, was applied to measurements of the neutron spectrum in a reactor. A number of different materials were irradiated to determine the most practical ones for use as multiple threshold detectors. These results, as well as counting techniques and corrections, are presented. Some materials used include aluminum, alloys of Al -Ni, aluminum-- nickel oxides, and magesium orthophosphates. (auth)

Treatment verification and in vivo dosimetry for total body irradiation using thermoluminescent and semiconductor detectors

International Nuclear Information System (INIS)

Oliveira, F.F.; Amaral, L.L.; Costa, A.M.; Netto, T.G.

2014-01-01

The objective of this work is the characterization of thermoluminescent and semiconductor detectors and their applications in treatment verification and in vivo dosimetry for total body irradiation (TBI) technique. Dose measurements of TBI treatment simulation performed with thermoluminescent detectors inserted in the holes of a “Rando anthropomorphic phantom” showed agreement with the prescribed dose. For regions of the upper and lower chest where thermoluminescent detectors received higher doses it was recommended the use of compensating dose in clinic. The results of in vivo entrance dose measurements for three patients are presented. The maximum percentual deviation between the measurements and the prescribed dose was 3.6%, which is consistent with the action level recommended by the International Commission on Radiation Units and Measurements (ICRU), i.e., ±5%. The present work to test the applicability of a thermoluminescent dosimetric system and of a semiconductor dosimetric system for performing treatment verification and in vivo dose measurements in TBI techniques demonstrated the value of these methods and the applicability as a part of a quality assurance program in TBI treatments. - Highlights: • Characterization of a semiconductor dosimetric system. • Characterization of a thermoluminescent dosimetric system. • Application of the TLDs for treatment verification in total body irradiation treatments. • Application of semiconductor detectors for in vivo dosimetry in total body irradiation treatments. • Implementation of in vivo dosimetry as a part of a quality assurance program in radiotherapy

Evidence for plasma effect on charge collection efficiency in proton irradiated GaAs detectors

CERN Document Server

Nava, F; Canali, C; Vittone, E; Polesello, P; Biggeri, U; Leroy, C

1999-01-01

The radiation damage in 100 mu m thick Schottky diodes made on semi-insulating undoped GaAs materials, were studied using alpha-, beta-, proton- and gamma-spectroscopy as well as I-V measurements. The results have been analysed within the framework of the Hecht model to investigate the influence of the plasma produced by short-range strongly ionising particles on the detector performance after 24 GeV proton irradiation. It has been found that with the mean free drift lengths for electrons and holes determined from alpha-spectra in overdepleted detectors, the charge collection efficiency for beta-particles, cce subbeta, is well predicted in the unirradiated detectors, while in the most irradiated ones, the cce subbeta is underestimated by more than 40%. The observed disagreement can be explained by assuming that the charge carrier recombination in the plasma region of such detectors, becomes significant.

Proton irradiation of CVD diamond detectors for high-luminosity experiments at the LHC

Energy Technology Data Exchange (ETDEWEB)

Meier, D. E-mail: dirk.meier@cern.ch.; Adam, W.; Bauer, C.; Berdermann, E.; Bergonzo, P.; Bogani, F.; Borchi, E.; Bruzzi, M.; Colledani, C.; Conway, J.; Dabrowski, W.; Delpierre, P.; Deneuville, A.; Dulinski, W.; Eijk, B. van; Fallou, A.; Foulon, F.; Friedl, M.; Jany, C.; Gan, K.K.; Gheeraert, E.; Grigoriev, E.; Hallewell, G.; Hall-Wilton, R.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kania, D.; Kaplon, J.; Kass, R.; Knoepfle, K.T.; Krammer, M.; Manfredi, P.F.; Marshall, R.D.; Mishina, M.; Le Normand, F.; Pan, L.S.; Palmieri, V.G.; Pernegger, H.; Pernicka, M.; Peitz, A.; Pirollo, S.; Pretzl, K.; Re, V.; Riester, J.L.; Roe, S.; Roff, D.; Rudge, A.; Schnetzer, S.; Sciortino, S.; Speziali, V.; Stelzer, H.; Stone, R.; Tapper, R.J.; Tesarek, R.; Thomson, G.B.; Trawick, M.; Trischuk, W.; Turchetta, R.; Walsh, A.M.; Wedenig, R.; Weilhammer, P.; Ziock, H.; Zoeller, M

1999-04-21

CVD diamond shows promising properties for use as a position-sensitive detector for experiments in the highest radiation areas at the Large Hadron Collider. In order to study the radiation hardness of diamond we exposed CVD diamond detector samples to 24 Gev/c and 500 Mev protons up to a fluence of 5x10{sup 15} p/cm{sup 2}. We measured the charge collection distance, the average distance electron-hole pairs move apart in an external electric field, and leakage currents before, during, and after irradiation. The charge collection distance remains unchanged up to 1x10{sup 15} p/cm{sup 2} and decreases by {approx}40% at 5x10{sup 15} p/cm{sup 2}. Leakage currents of diamond samples were below 1 pA before and after irradiation. The particle-induced currents during irradiation correlate well with the proton flux. In contrast to diamond, a silicon diode, which was irradiated for comparison, shows the known large increase in leakage current. We conclude that CVD diamond detectors are radiation hard to 24 GeV/c and 500 MeV protons up to at least 1x10{sup 15}p/cm{sup 2} without signal loss.

Influence for high intensity irradiation on characteristics of silicon strip-detectors

International Nuclear Information System (INIS)

Anokhin, I.E.; Pugatch, V.M.; Zinets, O.S.

1995-01-01

Full text: Silicon strip detectors (SSD) are widely used for the coordinate determination of short-range as well as minimum ionizing particles with high spatial resolution. Submicron position sensitivity of strip-detectors for short-range particles has been studied by means of two dimensional analyses of charges collected by neighboring strips as well as by measurement of charge collection times [1]. Silicon strip detectors was also used for testing high energy electron beam [2]. Under large fluences the radiation defects are stored and such characteristics of strip-detectors as an accuracy of the coordinate determination and the registration efficiency are significantly changed. Radiation defects lead to a decrease of the lifetime and mobility of charge carriers and therefore to changes of conditions for the charge collection in detectors. The inhomogeneity in spatial distribution if defects and electrical field plays an important role in the charge collection. In this report the role of the diffusion and drift in the charge collection in silicon strip-detectors under irradiation up to 10 Mrad has been studied. The electric field distribution and its dependence on the radiation dose in the detector have been calculated. It is shown that for particles incident between adjacent strips the coordinate determination precision depends strongly on the detector geometry and the electric field distribution, particularly in the vicinity of strips. Measuring simultaneously the collected charges and collection times on adjacent strips one can essentially improve reliability of the coordinate determination for short-range particles. Usually SSD are fabricated on n-type wafers. It is well known that under high intensity irradiation n-Si material converts into p-Si as far as p-type silicon is more radiative hard than n-type silicon [3] it is reasonable to fabricate SSD using high resistivity p-Si. Characteristics of SSD in basis n-and P-Si have been compared and higher

Nickel Foil as Transmutation Detector for Neutron Fluence Measurements

Directory of Open Access Journals (Sweden)

Klupák Vít

2016-01-01

Full Text Available Activation detectors are very often used for determination of the neutron fluence in reactor dosimetry. However, there are few disadvantages concerning these detectors; it is the demand of the knowledge of the irradiation history and a loss of information due to a radioactive decay in time. Transmutation detectors TMD could be a solution in this case. The transmutation detectors are materials in which stable or long-lived nuclides are produced by nuclear reactions with neutrons. From a measurement of concentration of these nuclides, neutron fluence can be evaluated regardless of the cooling time.

Self-Powered Neutron Detector Calibration Using a Large Vertical Irradiation Hole of HANARO

OpenAIRE

Kim Myong-Seop; Park Byung-Gun; Kang Gi-Doo

2018-01-01

A calibration technology of the self-powered neutron detectors (SPNDs) using a large vertical irradiation hole of HANARO is developed. The 40 Rh-SPNDs are installed on the polycarbonate plastic support, and the gold wires with the same length as the effective length of the rhodium emitter of the SPND are also installed to measure the neutron flux on the SPND. They are irradiated at a low reactor power, and the SPND current is measured using the pico-ammeter. The external gamma-rays which affe...

MCNPX calculations for electron irradiated semiconductor detectors

International Nuclear Information System (INIS)

Sedlackova, K.; Necas, V.; Sagatova, A.; Zatko, B.

2014-01-01

This study aimed to treat some practical problems of (not only) semiconductor material irradiation by high energy electron beam using MCNPX simulation code. The relation between the absorbed dose and the fluency was found and the energy distribution of electron flux density was simulated on the top and back side of 270 μm thick GaAs, SiC and Si detectors. Furthermore, the dose depth profiles were calculated for GaAs, SiC and Si materials irradiated by 4 and 5 MeV electron beams. For the GaAs detector, a very good agreement with the experiment was shown. To match the absolute values of the absorbed dose with experimentally obtained values, the electron source emissivity has to be determined in relation to the electron beam setting parameters. (authors)

Study of the response of a silicon detector irradiated with 1 MeV neutrons; Etude de la reponse d`un detecteur Si irradie par des neutrons de 1 MeV

Energy Technology Data Exchange (ETDEWEB)

Roy, P [Montreal Univ., PQ (Canada). Lab. de Physique Nucleaire

1994-12-31

The author studied the response of an n-type silicon detector irradiated with 1 MeV neutrons at fluences ranging from 0.26x10{sup 13} to 11.19x10{sup 13} neutrons/cm{sup 2}. The response of the irradiated detector to {sup 241}Am alpha particles was measured. 13 refs., 7 figs.

Developments, characterization and proton irradiation damage tests of AlN detectors for VUV solar observations

Energy Technology Data Exchange (ETDEWEB)

BenMoussa, A., E-mail: ali.benmoussa@stce.be [Solar Terrestrial Center of Excellence (STCE), Royal Observatory of Belgium, Circular Avenue 3, B-1180 Brussels (Belgium); Soltani, A.; Gerbedoen, J.-C [Institut d’Electronique, de Microélectronique et de Nanotechnologie (IEMN), F-59652 Villeneuve d’Ascq (France); Saito, T. [Department of Environment and Energy, Tohoku Institute of Technology, 35-1, Yagiyama-Kasumi-cho, Taihaku-ku, Sendai, Miyagi 982-8577 (Japan); Averin, S. [Fryazino Branch of the Kotel’nikov Institute of Radioengineering and Electronics of Russian Academy of Sciences, 141190 Square Vvedenski 1, Fryazino, Moscow Region (Russian Federation); Gissot, S.; Giordanengo, B. [Solar Terrestrial Center of Excellence (STCE), Royal Observatory of Belgium, Circular Avenue 3, B-1180 Brussels (Belgium); Berger, G. [Catholic University of Louvain-la-Neuve, Chemin du Cyclotron 2, B-1348 Louvain la Neuve (Belgium); Kroth, U. [Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2-12, D-10587 Berlin (Germany); De Jaeger, J.-C. [Institut d’Electronique, de Microélectronique et de Nanotechnologie (IEMN), F-59652 Villeneuve d’Ascq (France); Gottwald, A. [Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2-12, D-10587 Berlin (Germany)

2013-10-01

For next generation spaceborne solar ultraviolet radiometers, innovative metal–semiconductor–metal detectors based on wurtzite aluminum nitride are being developed and characterized. A set of measurement campaigns and proton irradiation damage tests was carried out to obtain their ultraviolet-to-visible characterization and degradation mechanisms. First results on large area prototypes up to 4.3 mm diameter are presented here. In the wavelength range of interest, this detector is reasonably sensitive and stable under brief irradiation with a negligible low dark current (3–6 pA/cm{sup 2}). No significant degradation of the detector performance was observed after exposure to protons of 14.4 MeV energy, showing a good radiation tolerance up to fluences of 1 × 10{sup 11} protons/cm{sup 2}.

Fast neutron irradiation effects on CR-39 nuclear track detector for dosimetric applications

International Nuclear Information System (INIS)

Kader, M.H.

2005-01-01

The effect of neutron irradiation on the dosimetric properties of CR-39 solid-state nuclear track detector have been investigated. CR-39 samples were irradiated with neutrons of energies follow a Maxwellian distribution centered about 2 MeV. These samples were irradiated with different doses in the range 0.1-1 Sv. The background and track density were measured as a function of etching time. In addition, the dependence of sensitivity of CR-39 detector on the neutrons dose has been investigated. The results show that the Sensitivity started to increase at 0.4 Sv neutrons dose, so this sample were chosen to be a subject for further study to investigate the effect of gamma dose on its properties. The sample irradiated with 0.4 Sv were exposed to different doses of gamma rays at levels between 10 and 80 kGy. The effect of gamma doses on the bulk etching rate VB, the track diameter and the sensitivity of the CR-39 samples was investigated. The results show that the dosimetric properties of CR-39 SSNTD are greatly affected by both neutron and gamma irradiation

Characterization of hybrid self-powered neutron detector under neutron irradiation

CERN Document Server

Nakamichi, M; Yamamura, C; Nakazawa, M; Kawamura, H

2000-01-01

To evaluate the irradiation behaviour of a blanket mock-up on in-pile functional test, it is necessary to measure the neutron flux change in the in-pile mock-up by a neutron detector, such as the self-powered neutron detector (SPND). With its small-sized emitter, which has high sensitivity and fast response time, SPND is an indispensable tool in order to measure the local neutron flux change. In the case of an in-pile functional test, it is necessary that response time is less than 1s and ratio of SPND output current is more than 0.3 of output current of SPND with Rh emitter. Therefore, a hybrid SPND with high sensitivity and fast response time was developed. This hybrid SPND used a hybrid emitter, i.e. Co cladded Pt-13%Rh.

Measurements on irradiated L1 sensor prototypes for the D0 Run IIb silicon detector project

International Nuclear Information System (INIS)

Ahsan, M.; Bolton, T.; Carnes, K.; Demarteau, M.; Demina, R.; Gray, T.; Korjenevski, S.; Lehner, F.; Lipton, R.; Mao, H.S.; McCarthy, R.

2010-01-01

We report on irradiation studies of Hamamatsu prototype silicon microstrip detectors for layer 1 of the D0 upgrade project for Run IIb. The irradiation was carried out with 10 MeV protons up to proton fluence of 10 14 p/cm 2 at the J.R. Macdonald Laboratory, Manhatten, KS. The flux calibration was carefully checked using different dose normalization techniques. The results based on the obtained sensor leakage currents after irradiation show that the NIEL scaling hypothesis for low energy protons has to be applied with great care. We observe 30-40% less radiation damage in silicon for 10 MeV proton exposure than is expected from the predicted NIEL scaling.

Measurements on irradiated L1 sensor prototypes for the D0 Run IIb silicon detector project

Energy Technology Data Exchange (ETDEWEB)

Ahsan, M.; Bolton, T.; Carnes, K.; /Kansas State U.; Demarteau, M.; /Fermilab; Demina, R.; /Rochester U.; Gray, T.; /Kansas State U.; Korjenevski, S.; /Rochester U.; Lehner, F.; /Zurich U.; Lipton, R.; Mao, H.S.; /Fermilab; McCarthy, R.; /SUNY, Stony Brook /Kansas State U. /Fermilab

2010-01-01

We report on irradiation studies of Hamamatsu prototype silicon microstrip detectors for layer 1 of the D0 upgrade project for Run IIb. The irradiation was carried out with 10 MeV protons up to proton fluence of 10{sup 14} p/cm{sup 2} at the J.R. Macdonald Laboratory, Manhatten, KS. The flux calibration was carefully checked using different dose normalization techniques. The results based on the obtained sensor leakage currents after irradiation show that the NIEL scaling hypothesis for low energy protons has to be applied with great care. We observe 30-40% less radiation damage in silicon for 10 MeV proton exposure than is expected from the predicted NIEL scaling.

Characterization of 150 $\\mu$m thick epitaxial silicon detectors from different producers after proton irradiation

CERN Document Server

Hoedlmoser, H; Haerkoenen, J; Kronberger, M; Trummer, J; Rodeghiero, P

2007-01-01

Epitaxial (EPI) silicon has recently been investigated for the development of radiation tolerant detectors for future high-luminosity HEP experiments. A study of 150 mm thick EPI silicon diodes irradiated with 24GeV=c protons up to a fluence of 3 1015 p=cm2 has been performed by means of Charge Collection Efficiency (CCE) measurements, investigations with the Transient Current Technique (TCT) and standard CV=IV characterizations. The aim of the work was to investigate the impact of radiation damage as well as the influence of the wafer processing on the material performance by comparing diodes from different manufacturers. The changes of CCE, full depletion voltage and leakage current as a function of fluence are reported. While the generation of leakage current due to irradiation is similar in all investigated series of detectors, a difference in the effective doping concentration can be observed after irradiation. In the CCE measurements an anomalous drop in performance was found even for diodes exposed to ...

Progress towards vertical transport study of proton-irradiated InAs/GaSb type-II strained-layer superlattice materials for space-based infrared detectors using magnetoresistance measurements

Science.gov (United States)

Malone, Mitchell C.; Morath, Christian P.; Fahey, Stephen; Klein, Brianna; Cowan, Vincent M.; Krishna, Sanjay

2015-09-01

InAs/GaSb type-II strained-layer superlattice (T2SLS) materials are being considered for space-based infrared detector applications. However, an inadequate understanding of the role of carrier transport, specifically the vertical mobility, in the radiation tolerance of T2SLS detectors remains. Here, progress towards a vertical transport study of proton-irradiated, p-type InAs/GaSb T2SLS materials using magnetoresistance measurements is reported. Measurements in the growth direction of square mesas formed from InAs/GaSb superlattice material were performed using two distinct contact geometries in a Kelvin mode setup at variable magnetic fields, ranging from -9 T to 9 T, and temperatures, ranging from 5 K and 300 K. The results here suggested multi-carrier conduction and a field-dependent series resistance from the contact layer were present. The implications of these results and the plans for future magnetoresistance measurements on proton-irradiated T2SLS materials are discussed.

The effect of ArF laser irradiation (193 nm) on the photodegradation and etching properties of alpha-irradiated CR-39 detectors

Energy Technology Data Exchange (ETDEWEB)

Shakeri Jooybari, B. [Department of Energy Engineering and Physics, Amirkabir University of Technology, P.O. Box 15875-4413, Tehran, Islamic Republic of Iran (Iran, Islamic Republic of); Nuclear Science and Technology Research Institute (NSRT), Tehran, Islamic Republic of Iran (Iran, Islamic Republic of); Ghergherehchi, M. [College of Information and Technology/ school of Electronic and Electrical Engineering, Sungkyunkwan University, Suwon (Korea, Republic of); Afarideh, H., E-mail: hafarideh@aut.ac.ir [Department of Energy Engineering and Physics, Amirkabir University of Technology, P.O. Box 15875-4413, Tehran, Islamic Republic of Iran (Iran, Islamic Republic of); Lamehi-Rachti, M. [Nuclear Science and Technology Research Institute (NSRT), Tehran, Islamic Republic of Iran (Iran, Islamic Republic of)

2015-01-01

The effects of ArF laser irradiation (λ=193nm) at various fluences (energy dose or energy density) on the etching properties of pre-exposed (laser + alpha) CR-39 detectors were studied. First, UV–Vis and Fourier transform infrared (FTIR) spectra were acquired for non-laser-irradiated and laser-irradiated samples to detect the influence of the ArF laser on the chemical modification of the CR-39. Changes observed in the spectra indicated that the predominant process that occurred upon ArF laser irradiation was a bond-scission process. Thereafter, the mean track and bulk etching parameters were experimentally measured in ArF-laser-irradiated CR-39 detectors exposed to an alpha source ({sup 241}Am, E = 5.49 MeV). Inhomogeneous regions in the laser-irradiated side of the CR-39 demonstrated a variable etching rate on only the front side of the CR-39 detector. New equations are also presented for the average bulk etching rate for these inhomogeneous regions (front side). The mean bulk and track etching rates and the mean track dimensions increased in a fluence range of 0–37.03 mJ/cm{sup 2} because of photodegradation and the scission of chemical bonds, which are the predominant processes in this range. When the fluence was increased from 37.03 to 123.45 mJ/cm{sup 2}, the bulk and track etching rates and the track dimensions slowly decreased because of the formation of cross-linked structures on the CR-39 surface. The behavior of the bulk and track etching rates and the track dimensions appears to be proportional to the dose absorbed on the detector surface. It was observed that as the etching time was increased, the bulk and track etching rates and the track dimensions of the laser-irradiated samples decreased because of the shallow penetration depth of the 193 nm laser and the reduction in the oxygen penetration depth.

UV-irradiation effects on polyester nuclear track detector

International Nuclear Information System (INIS)

Agarwal, Chhavi; Kalsi, P.C.

2010-01-01

The effects of UV irradiation (λ=254 nm) on polyester nuclear track detector have been investigated employing bulk-etch technique, UV-visible spectrophotometry and infra-red spectrometry (FTIR). The activation energy values for bulk-etching were found to decrease with the UV-irradiation time indicating the scission of the polymer. Not much shift in the absorption edge due to UV irradiation was seen in the UV-visible spectra. FTIR studies also indicate the scission of the chemical bonds, thereby further validating the bulk-etch rate results.

Precision rectifier detectors for ac resistance bridge measurements with application to temperature control systems for irradiation creep experiments

Energy Technology Data Exchange (ETDEWEB)

Duncan, M. G.

1977-05-01

The suitability of several temperature measurement schemes for an irradiation creep experiment is examined. It is found that the specimen resistance can be used to measure and control the sample temperature if compensated for resistance drift due to radiation and annealing effects. A modified Kelvin bridge is presented that allows compensation for resistance drift by periodically checking the sample resistance at a controlled ambient temperature. A new phase-insensitive method for detecting the bridge error signals is presented. The phase-insensitive detector is formed by averaging the magnitude of two bridge voltages. Although this method is substantially less sensitive to stray reactances in the bridge than conventional phase-sensitive detectors, it is sensitive to gain stability and linearity of the rectifier circuits. Accuracy limitations of rectifier circuits are examined both theoretically and experimentally in great detail. Both hand analyses and computer simulations of rectifier errors are presented. Finally, the design of a temperature control system based on sample resistance measurement is presented. The prototype is shown to control a 316 stainless steel sample to within a 0.15/sup 0/C short term (10 sec) and a 0.03/sup 0/C long term (10 min) standard deviation at temperatures between 150 and 700/sup 0/C. The phase-insensitive detector typically contributes less than 10 ppM peak resistance measurement error (0.04/sup 0/C at 700/sup 0/C for 316 stainless steel or 0.005/sup 0/C at 150/sup 0/C for zirconium).

The effect of charge collection recovery in silicon p-n junction detectors irradiated by different particles

International Nuclear Information System (INIS)

Verbitskaya, E.; Abreu, M.; Anbinderis, P.; Anbinderis, T.; D'Ambrosio, N.; Boer, W. de; Borchi, E.; Borer, K.; Bruzzi, M.; Buontempo, S.; Casagrande, L.; Chen, W.; Cindro, V.; Dezillie, B.; Dierlamm, A.; Eremin, V.; Gaubas, E.; Gorbatenko, V.; Granata, V.; Grigoriev, E.; Grohmann, S.; Hauler, F.; Heijne, E.; Heising, S.; Hempel, O.; Herzog, R.; Haerkoenen, J.; Ilyashenko, I.; Janos, S.; Jungermann, L.; Kalesinskas, V.; Kapturauskas, J.; Laiho, R.; Li, Z.; Mandic, I.; De Masi, Rita; Menichelli, D.; Mikuz, M.; Militaru, O.; Niinikoski, T.O.; O'Shea, V.; Pagano, S.; Palmieri, V.G.; Paul, S.; Perea Solano, B.; Piotrzkowski, K.; Pirollo, S.; Pretzl, K.; Rato Mendes, P.; Ruggiero, G.; Smith, K.; Sonderegger, P.; Sousa, P.; Tuominen, E.; Vaitkus, J.; Da Via, C.; Wobst, E.; Zavrtanik, M.

2003-01-01

The recovery of the charge collection efficiency (CCE) at low temperatures, the so-called 'Lazarus effect', was studied in Si detectors irradiated by fast reactor neutrons, by protons of medium and high energy, by pions and by gamma-rays. The experimental results show that the Lazarus effect is observed: (a) after all types of irradiation; (b) before and after space charge sign inversion; (c) only in detectors that are biased at voltages resulting in partial depletion at room temperature. The experimental temperature dependence of the CCE for proton-irradiated detectors shows non-monotonic behaviour with a maximum at a temperature defined as the CCE recovery temperature. The model of the effect for proton-irradiated detectors agrees well with that developed earlier for detectors irradiated by neutrons. The same midgap acceptor-type and donor-type levels are responsible for the Lazarus effect in detectors irradiated by neutrons and by protons. A new, abnormal 'zigzag'-shaped temperature dependence of the CCE was observed for detectors irradiated by all particles (neutrons, protons and pions) and by an ultra-high dose of γ-rays, when operating at low bias voltages. This effect is explained in the framework of the double-peak electric field distribution model for heavily irradiated detectors. The redistribution of the space charge region depth between the depleted regions adjacent to p + and n + contacts is responsible for the 'zigzag'- shaped curves. It is shown that the CCE recovery temperature increases with reverse bias in all detectors, regardless of the type of radiation

Characterization of hybrid self-powered neutron detector under neutron irradiation

Energy Technology Data Exchange (ETDEWEB)

Nakamichi, M. E-mail: masaru@oarai.jaeri.go.jp; Nagao, Y.; Yamamura, C.; Nakazawa, M.; Kawamura, H

2000-11-01

To evaluate the irradiation behaviour of a blanket mock-up on in-pile functional test, it is necessary to measure the neutron flux change in the in-pile mock-up by a neutron detector, such as the self-powered neutron detector (SPND). With its small-sized emitter, which has high sensitivity and fast response time, SPND is an indispensable tool in order to measure the local neutron flux change. In the case of an in-pile functional test, it is necessary that response time is less than 1s and ratio of SPND output current is more than 0.3 of output current of SPND with Rh emitter. Therefore, a hybrid SPND with high sensitivity and fast response time was developed. This hybrid SPND used a hybrid emitter, i.e. Co cladded Pt-13%R000.

Field oxide radiation damage measurements in silicon strip detectors

Energy Technology Data Exchange (ETDEWEB)

Laakso, M [Particle Detector Group, Fermilab, Batavia, IL (United States) Research Inst. for High Energy Physics (SEFT), Helsinki (Finland); Singh, P; Shepard, P F [Dept. of Physics and Astronomy, Univ. Pittsburgh, PA (United States)

1993-04-01

Surface radiation damage in planar processed silicon detectors is caused by radiation generated holes being trapped in the silicon dioxide layers on the detector wafer. We have studied charge trapping in thick (field) oxide layers on detector wafers by irradiating FOXFET biased strip detectors and MOS test capacitors. Special emphasis was put on studying how a negative bias voltage across the oxide during irradiation affects hole trapping. In addition to FOXFET biased detectors, negatively biased field oxide layers may exist on the n-side of double-sided strip detectors with field plate based n-strip separation. The results indicate that charge trapping occurred both close to the Si-SiO[sub 2] interface and in the bulk of the oxide. The charge trapped in the bulk was found to modify the electric field in the oxide in a way that leads to saturation in the amount of charge trapped in the bulk when the flatband/threshold voltage shift equals the voltage applied over the oxide during irradiation. After irradiation only charge trapped close to the interface is annealed by electrons tunneling to the oxide from the n-type bulk. (orig.).

Operation of a hemispherical detector for LET measurements

International Nuclear Information System (INIS)

Schell, M.C.; DeLuca, P.M. Jr.; Pearson, D.W.

1982-01-01

A hemispherical ΔE/E detector has been constructed and tested for the measurement of linear-energy-transfer distributions of charged particles induced by fast neutrons. The initial performance test results and LET distributions from 14.8-MeV monoenergetic neutron irradiation in free space of carbon, lead, and Al50-plastic are presented

Scanning transient current study of the I-V stabilization phenomena in silicon detectors irradiated by fast neutrons

International Nuclear Information System (INIS)

Eremin, V.; Verbitskaya, E.; Sidorov, A.; Fretwurst, E.; Lindstrom, G.

1996-03-01

Investigation of the I-V stabilization phenomena in neutron irradiated silicon detectors has been carried out using scanning transient current technique (STCT) on non-irradiated PP + -p-n + detectors. The PP + -p-n + detectors were used to simulate the PP + -n-n + detectors irradiated beyond the space charge sign inversion (SCSI). Two mechanisms partially responsible for the I- V stabilization have been identified

Measuring device for the distribution of burn-up degree in fuel assembly irradiated in nuclear reactor

International Nuclear Information System (INIS)

Kumanomido, Hironori

1989-01-01

The object of the invention is to measure the distribution of burn-up degree, of fuel assemblies irradiated in a nuclear reactor in a short time and exactly. That is, the device comprises a device main body having substantially the same length as that for the axial length of a fuel assembly and a detector container disposed axially slidably to the main body. A plurality of radiation detectors are arranged at an equi-axial pitch and contained in the container. The container is caused to slide at a pitch equal to the equi-axial distance of the detectors. In the device having thus been constituted, measurement is conducted at least for twice at an axial position on the side of a fuel assembly irradiated in the nuclear reactor and a position caused to slide therefrom by one pitch. Based on the result, the sensitivities between each of the detectors are compared and the relative sensitivity of the radiation detectors is calibrated. Accordingly, the sensitivity between each of the detectors can be calibrated rapidly and easily. As a result, the distribution of the burn-up degree, etc of irradiated fuel assembly can be measured exactly. (K.M.)

The Siegen automatic measuring system for nuclear track detectors: new developments

International Nuclear Information System (INIS)

Noll, A.; Rusch, G.; Roecher, H.; Dreute, J.; Heinrich, W.

1988-01-01

Starting ten years ago we developed completely automatic scanning and measuring systems for nuclear track detectors. In this paper we describe some new developments. Our autofocus systems based on the contrast of the video picture and on a laser autofocus have been improved in speed and in reliability. Based on new algorithms, faster programs have been developed to scan for nuclear tracks in plastic detectors. Methods for separation of overlapping tracks have been improved. Interactive programs for track measurements have been developed which are very helpful for space bio-physics experiments. Finally new methods for track measurements in nuclear emulsions irradiated with a beam perpendicular to the detector surface are described in this paper. (author)

Developing a fast simulator for irradiated silicon detectors

CERN Document Server

Diez Gonzalez-Pardo, Alvaro

2015-01-01

Simulation software for irradiated silicon detectors has been developed on the basis of an already existing C++ simulation software called TRACS[1]. This software has been already proven useful in understanding non-irradiated silicon diodes and microstrips. In addition a wide variety of user-focus features has been implemented to improve on TRACS flexibility. Such features include an interface to allow any program to leverage TRACS functionalities, a configuration file and improved documentation.

Performance of silicon pad detectors after mixed irradiations with neutrons and fast charged hadrons

Energy Technology Data Exchange (ETDEWEB)

Kramberger, G. [Jozef Stefan Institute, Department of Physics, University of Ljubljana, Jamova 39, SI-1000 Ljubljana (Slovenia)], E-mail: Gregor.Kramberger@ijs.si; Cindro, V.; Dolenc, I.; Mandic, I.; Mikuz, M.; Zavrtanik, M. [Jozef Stefan Institute, Department of Physics, University of Ljubljana, Jamova 39, SI-1000 Ljubljana (Slovenia)

2009-10-11

A large set of silicon pad detectors produced on MCz and FZ wafer of p- and n-type was irradiated in two steps, first by fast charged hadrons followed by reactor neutrons. In this way the irradiations resemble the real irradiation fields at LHC. After irradiations controlled annealing started in steps during which the evolution of full depletion voltage, leakage current and charge collection efficiency was monitored. The damage introduced by different irradiation particles was found to be additive. The most striking consequence of that is a decrease of the full depletion voltage for n-type MCz detectors after additional neutron irradiation. This confirms that effective donors introduced by charged hadron irradiation are compensated by acceptors from neutron irradiation.

Performance of silicon pad detectors after mixed irradiations with neutrons and fast charged hadrons

International Nuclear Information System (INIS)

Kramberger, G.; Cindro, V.; Dolenc, I.; Mandic, I.; Mikuz, M.; Zavrtanik, M.

2009-01-01

A large set of silicon pad detectors produced on MCz and FZ wafer of p- and n-type was irradiated in two steps, first by fast charged hadrons followed by reactor neutrons. In this way the irradiations resemble the real irradiation fields at LHC. After irradiations controlled annealing started in steps during which the evolution of full depletion voltage, leakage current and charge collection efficiency was monitored. The damage introduced by different irradiation particles was found to be additive. The most striking consequence of that is a decrease of the full depletion voltage for n-type MCz detectors after additional neutron irradiation. This confirms that effective donors introduced by charged hadron irradiation are compensated by acceptors from neutron irradiation.

Dynamic Efficiency Measurements for Irradiated ATLAS Pixel Single Chip Modules

CERN Document Server

Pfaff, Mike; Grosse-Knetter, Jorn

2011-01-01

The ATLAS pixel detector is the innermost subdetector of the ATLAS experiment. Due to this, the pixel detector has to be particularly radiation hard. In this diploma thesis effects on the sensor and the electronics which are caused by irradiation are examined. It is shown how the behaviour changes between an unirradiated sample and a irradiated sample, which was treated with the same radiation dose that is expected at the end of the lifetime of ATLAS. For this study a laser system, which is used for dynamic efficiency measurements was constructed. Furthermore, the behaviour of the noise during the detection of a particle was evaluated studied.

Charge collection efficiency recovery in heavily irradiated silicon detectors operated at cryogenic temperatures

CERN Document Server

Da Vià, C; Berglund, P; Borchi, E; Borer, K; Bruzzi, Mara; Buontempo, S; Casagrande, L; Chapuy, S; Cindro, V; Dimcovski, Zlatomir; D'Ambrosio, N; de Boer, Wim; Dezillie, B; Esposito, A P; Granat, V; Grigoriev, E; Heijne, Erik H M; Heising, S; Janos, S; Koivuniemi, J H; Konotov, I; Li, Z; Lourenço, C; Mikuz, M; Niinikoski, T O; Pagano, S; Palmieri, V G; Paul, S; Pirollo, S; Pretzl, Klaus P; Ropotar, I; Ruggiero, G; Salmi, J; Seppä, H; Suni, I; Smith, K; Sonderegger, P; Valtonen, M J; Zavrtanik, M

1998-01-01

The charge collection efficiency (CCE) of high resistivity silicon detectors, previously neutron irradiated up to 2*10/sup 15/ n/cm/sup 2/, was measured at different cryogenic temperatures and different bias voltages. In order to $9 study reverse annealing (RA) effects, a few samples were heated to 80 degrees C and kept at room temperature for several months after irradiation. For comparison other samples (NRA) where kept at -10 C after irradiation. The RA and $9 NRA samples, measured at 250 V forward and reverse bias voltage, present a common temperature threshold at 150 K. Below 120 K the CCE is constant and ranges between 55and 65 0.000000or the RA and NRA sample respectively. Similar CCE $9 was measured for a device processed with low resistivity contacts (OHMIC), opening the prospect for a consistent reduction of the cost of large area particle tracking. (7 refs).

Radiation damage of pixelated photon detector by neutron irradiation

Energy Technology Data Exchange (ETDEWEB)

Nakamura, Isamu [KEK, 1-1 Oho Tsukuba 305-0801 (Japan)], E-mail: isamu.nakamura@kek.jp

2009-10-21

Radiation Damage of Pixelated Photon Detector by neutron irradiation is reported. MPPC, one of PPD or Geiger-mode APD, developed by Hamamatsu Photonics, is planned to be used in many high energy physics experiments. In such experiments radiation damage is a serious issue. A series of neutron irradiation tests is performed at the Reactor YAYOI of the University of Tokyo. MPPCs were irradiated at the reactor up to 10{sup 12}neutron/cm{sup 2}. In this paper, the effect of neutron irradiation on the basic characteristics of PPD including gain, noise rate, photon detection efficiency is presented.

Design for measurement system of Doppler broadening profiles with the coincidence technique using a NaI detector in colinear geometry with the Ge detector

International Nuclear Information System (INIS)

Mori, Kazuteru; Uedono, Akira; Tanigawa, Shoichiro; Nakai, Katsuhiko

1998-01-01

The measurement system for Doppler broadening profiles with the coincidence technique using a NaI detector in colinear geometry with a Ge detector was developed. The principle of measurement system with the coincidence technique between the NaI detector and the Ge detector was described. Application of the system for the detection of vacancy-type defects introduced by electron irradiation in Czochralski-(Cz) grown Si was shown. Detail in the difference between the Doppler broadening profiles for Cz-Si and Si grown by the floating-zone method was also obtained. (author)

Design for measurement system of Doppler broadening profiles with the coincidence technique using a NaI detector in colinear geometry with the Ge detector

Energy Technology Data Exchange (ETDEWEB)

Mori, Kazuteru; Uedono, Akira; Tanigawa, Shoichiro [Tsukuba Univ., Ibaraki (Japan). Inst. of Materials Science; Nakai, Katsuhiko

1998-08-01

The measurement system for Doppler broadening profiles with the coincidence technique using a NaI detector in colinear geometry with a Ge detector was developed. The principle of measurement system with the coincidence technique between the NaI detector and the Ge detector was described. Application of the system for the detection of vacancy-type defects introduced by electron irradiation in Czochralski-(Cz) grown Si was shown. Detail in the difference between the Doppler broadening profiles for Cz-Si and Si grown by the floating-zone method was also obtained. (author)

Research on the measurement of the ultraviolet irradiance in the xenon lamp aging test chamber

Science.gov (United States)

Ji, Muyao; Li, Tiecheng; Lin, Fangsheng; Yin, Dejin; Cheng, Weihai; Huang, Biyong; Lai, Lei; Xia, Ming

2018-01-01

This paper briefly introduces the methods of calibrating the irradiance in the Xenon lamp aging test chamber. And the irradiance under ultraviolet region is mainly researched. Three different detectors whose response wave range are respectively UVA (320 400nm), UVB (275 330nm) and UVA+B (280 400nm) are used in the experiment. Through comparing the measuring results with different detectors under the same xenon lamp source, we discuss the difference between UVA, UVB and UVA+B on the basis of the spectrum of the xenon lamp and the response curve of the detectors. We also point out the possible error source, when use these detectors to calibrate the chamber.

Characterization of 150μm thick epitaxial silicon detectors from different producers after proton irradiation

International Nuclear Information System (INIS)

Hoedlmoser, H.; Moll, M.; Haerkoenen, J.; Kronberger, M.; Trummer, J.; Rodeghiero, P.

2007-01-01

Epitaxial (EPI) silicon has recently been investigated for the development of radiation tolerant detectors for future high-luminosity HEP experiments. A study of 150μm thick EPI silicon diodes irradiated with 24GeV/c protons up to a fluence of 3x10 15 p/cm 2 has been performed by means of Charge Collection Efficiency (CCE) measurements, investigations with the Transient Current Technique (TCT) and standard CV/IV characterizations. The aim of the work was to investigate the impact of radiation damage as well as the influence of the wafer processing on the material performance by comparing diodes from different manufacturers. The changes of CCE, full depletion voltage and leakage current as a function of fluence are reported. While the generation of leakage current due to irradiation is similar in all investigated series of detectors, a difference in the effective doping concentration can be observed after irradiation. In the CCE measurements an anomalous drop in performance was found even for diodes exposed to very low fluences (5x10 13 p/cm 2 ) in all measured series. This result was confirmed for one series of diodes in TCT measurements with an infrared laser. TCT measurements with a red laser showed no type inversion up to fluences of 3x10 15 p/cm 2 for n-type devices whereas p-type diodes undergo type inversion from p- to n-type for fluences higher than ∼2x10 14 p/cm 2

A comprehensive analysis of irradiated silicon detectors at cryogenic temperatures

CERN Document Server

Santocchia, A; Hall, G; MacEvoy, B; Moscatelli, F; Passeri, D; Pignatel, Giogrio Umberto

2003-01-01

The effect of particle irradiation on high-resistivity silicon detectors has been extensively studied with the goal of engineering devices able to survive the very challenging radiation environment at the CERN Large Hadron Collider (LHC). The main aspect under investigation has been the changes observed in detector effective doping concentration (N/sub eff/). We have previously proposed a mechanism to explain the evolution of N/sub eff/, whereby charge is exchanged directly between closely-spaced defect centres in the dense terminal clusters formed by hadron irradiation. This model has been implemented in both a commercial finite-element device simulator (ISE-TCAD) and a purpose-built simulation of interdefect charge exchange. To control the risk of breakdown due to the high leakage currents foreseen during ten years of LHC operation, silicon detectors will be operated below room temperature (around -10 degrees C). This, and more general current interest in the field of cryogenic operation, has led us to inve...

Application of Faraday cup array detector in measurement of electron-beam distribution homogeneity

International Nuclear Information System (INIS)

Xu Zhiguo; Wang Jinchuan; Xiao Guoqing; Guo Zhongyan; Wu Lijie; Mao Ruishi; Zhang Li

2005-01-01

It is described that a kind of Faraday cup array detector, which consists of Faraday cup, suppressor electrode insulation PCB board, Base etc. The homogeneity of electron-beam distribution is measured and the absorbed dose for the irradiated sample is calculated. The results above provide the important parameters for the irradiation experiment and the improvement for the quality of electron beam. (authors)

Modeling of displacement damage in silicon carbide detectors resulting from neutron irradiation

Science.gov (United States)

Khorsandi, Behrooz

There is considerable interest in developing a power monitor system for Generation IV reactors (for instance GT-MHR). A new type of semiconductor radiation detector is under development based on silicon carbide (SiC) technology for these reactors. SiC has been selected as the semiconductor material due to its superior thermal-electrical-neutronic properties. Compared to Si, SiC is a radiation hard material; however, like Si, the properties of SiC are changed by irradiation by a large fluence of energetic neutrons, as a consequence of displacement damage, and that irradiation decreases the life-time of detectors. Predictions of displacement damage and the concomitant radiation effects are important for deciding where the SiC detectors should be placed. The purpose of this dissertation is to develop computer simulation methods to estimate the number of various defects created in SiC detectors, because of neutron irradiation, and predict at what positions of a reactor, SiC detectors could monitor the neutron flux with high reliability. The simulation modeling includes several well-known---and commercial---codes (MCNP5, TRIM, MARLOWE and VASP), and two kinetic Monte Carlo codes written by the author (MCASIC and DCRSIC). My dissertation will highlight the displacement damage that may happen in SiC detectors located in available positions in the OSURR, GT-MHR and IRIS. As extra modeling output data, the count rates of SiC for the specified locations are calculated. A conclusion of this thesis is SiC detectors that are placed in the thermal neutron region of a graphite moderator-reflector reactor have a chance to survive at least one reactor refueling cycle, while their count rates are acceptably high.

Quantitative measurements of oxidative stress in mouse skin induced by X-ray irradiation

International Nuclear Information System (INIS)

Chi, Cuiping; Tanaka, Ryoko; Okuda, Yohei; Ikota, Nobuo; Ozawa, Toshihiko; Anzai, Kazunori; Yamamoto, Haruhiko; Urano, Shiro

2005-01-01

To find efficient methods to evaluate oxidative stress in mouse skin caused by X-ray irradiation, several markers and methodologies were examined. Hairless mice were irradiated with 50 Gy X-rays and skin homogenates or skin strips were prepared. Lipid peroxidation was measured using the skin homogenate as the level of thiobarbituric acid reactive substances. The level of lipid peroxidation increased with time after irradiation and was twice that of the control at 78 h. Electron spin resonance (ESR) spectra of skin strips showed a clear signal for the ascorbyl radical, which increased with time after irradiation in a manner similar to that of lipid peroxidation. To measure levels of glutathione (GSH) and its oxidized forms (GSSG) simultaneously, two high performance liquid chromatography (HPLC) methods, sample derivatization with 1-fluoro-2,4-dinitrobenzene and detection with a UV detector (method A) and no derivatization and detection with an electrochemical detector (method B), were compared and the latter was found to be better. No significant change was observed within 24 h after irradiation in the levels of GSH and GSSG measured by method B. The GSH/GSSG ratio may be a less sensitive parameter for the evaluation of acute oxidative stress caused by X-ray irradiation in the skin. Monitoring the ascorbyl radical seems to be a good way to evaluate oxidative stress in skin in vivo. (author)

Transmutation detectors

Energy Technology Data Exchange (ETDEWEB)

Viererbl, L., E-mail: vie@ujv.c [Research Centre Rez Ltd. (Czech Republic); Nuclear Research Institute Rez plc (Czech Republic); Lahodova, Z. [Research Centre Rez Ltd. (Czech Republic); Nuclear Research Institute Rez plc (Czech Republic); Klupak, V. [Nuclear Research Institute Rez plc (Czech Republic); Sus, F. [Research Centre Rez Ltd. (Czech Republic); Nuclear Research Institute Rez plc (Czech Republic); Kucera, J. [Research Centre Rez Ltd. (Czech Republic); Nuclear Physics Institute, Academy of Sciences of the Czech Republic (Czech Republic); Kus, P.; Marek, M. [Research Centre Rez Ltd. (Czech Republic); Nuclear Research Institute Rez plc (Czech Republic)

2011-03-11

We have designed a new type of detectors, called transmutation detectors, which can be used primarily for neutron fluence measurement. The transmutation detector method differs from the commonly used activation detector method in evaluation of detector response after irradiation. Instead of radionuclide activity measurement using radiometric methods, the concentration of stable non-gaseous nuclides generated by transmutation in the detector is measured using analytical methods like mass spectrometry. Prospective elements and nuclear reactions for transmutation detectors are listed and initial experimental results are given. The transmutation detector method could be used primarily for long-term measurement of neutron fluence in fission nuclear reactors, but in principle it could be used for any type of radiation that can cause transmutation of nuclides in detectors. This method could also be used for measurement in accelerators or fusion reactors.

Transmutation detectors

International Nuclear Information System (INIS)

Viererbl, L.; Lahodova, Z.; Klupak, V.; Sus, F.; Kucera, J.; Kus, P.; Marek, M.

2011-01-01

We have designed a new type of detectors, called transmutation detectors, which can be used primarily for neutron fluence measurement. The transmutation detector method differs from the commonly used activation detector method in evaluation of detector response after irradiation. Instead of radionuclide activity measurement using radiometric methods, the concentration of stable non-gaseous nuclides generated by transmutation in the detector is measured using analytical methods like mass spectrometry. Prospective elements and nuclear reactions for transmutation detectors are listed and initial experimental results are given. The transmutation detector method could be used primarily for long-term measurement of neutron fluence in fission nuclear reactors, but in principle it could be used for any type of radiation that can cause transmutation of nuclides in detectors. This method could also be used for measurement in accelerators or fusion reactors.

Charge collection efficiency of irradiated silicon detector operated at cryogenic temperatures

International Nuclear Information System (INIS)

Borer, K.; Janos, S.; Palmieri, V.G.; Dezillie, B.; Li, Z.; Collins, P.; Niinikoski, T.O.; Lourenco, C.; Sonderegger, P.; Borchi, E.; Bruzzi, M.; Pirollo, S.; Granata, V.; Pagano, S.; Chapuy, S.; Dimcovski, Z.; Grigoriev, E.; Bell, W.; Devine, S.R.H.; O'Shea, V.; Smith, K.; Berglund, P.; Boer, W. de; Hauler, F.; Heising, S.; Jungermann, L.; Casagrande, L.; Cindro, V.; Mikuz, M.; Zavartanik, M.; Via, C. da; Esposito, A.; Konorov, I.; Paul, S.; Schmitt, L.; Buontempo, S.; D'Ambrosio, N.; Pagano, S.; Ruggiero, G.; Eremin, V.; Verbitskaya, E.

2000-01-01

The charge collection efficiency (CCE) of heavily irradiated silicon diode detectors was investigated at temperatures between 77 and 200 K. The CCE was found to depend on the radiation dose, bias voltage value and history, temperature, and bias current generated by light. The detector irradiated to the highest fluence 2x10 15 n/cm 2 yields a MIP signal of at least 15000 e - both at 250 V forward bias voltage, and at 250 V reverse bias voltage in the presence of a light-generated current. The 'Lazarus effect' was thus shown to extend to fluences at least ten times higher than was previously studied

Initial Measurements On Pixel Detector Modules For The ATLAS Upgrades

CERN Document Server

Gallrapp, C; The ATLAS collaboration

2011-01-01

Sophisticated conditions in terms of peak and integrated luminosity in the Large Hadron Collider (LHC) will raise the ATLAS Pixel detector to its performance limits. Silicon planar, silicon 3D and diamond pixel sensors are three possible sensor technologies which could be implemented in the upcoming pixel detector upgrades of the ATLAS experiment. Measurements of the IV-behavior and measurements with radioactive Americium-241 and Strontium-90 are used to characterize the sensor properties and to understand the interaction between the ATLAS FE-I4 front-end chip and the sensor. Comparisons of results from before and after irradiation, which give a first impression on the charge collection properties of the different sensor technologies are presented.

Comparison of pad detectors produced on different silicon materials after irradiation with neutrons, protons and pions

International Nuclear Information System (INIS)

Kramberger, G.; Cindro, V.; Dolenc, I.; Mandic, I.; Mikuz, M.; Zavrtanik, M.

2010-01-01

A set of 44 pad detectors produced on p- and n-type MCz and Fz wafers was irradiated with 23 GeV protons, 200 MeV pions and reactor neutrons up to the equivalent fluences of Φ eq =3x10 15 cm -2 . The evolution of the full depletion voltage and the leakage current were monitored during short- and long-term annealing. At selected representative annealing steps, charge collection measurements were performed for all samples with LHC speed electronics. Measurements of full depletion voltage, leakage current and charge collection efficiency were compared for different irradiation particles and silicon materials.

Comparison of pad detectors produced on different silicon materials after irradiation with neutrons, protons and pions

Energy Technology Data Exchange (ETDEWEB)

Kramberger, G., E-mail: Gregor.Kramberger@ijs.s [Jozef Stefan Institute and Department of Physics, University of Ljubljana, SI-1000 Ljubljana (Slovenia); Cindro, V.; Dolenc, I.; Mandic, I.; Mikuz, M.; Zavrtanik, M. [Jozef Stefan Institute and Department of Physics, University of Ljubljana, SI-1000 Ljubljana (Slovenia)

2010-01-01

A set of 44 pad detectors produced on p- and n-type MCz and Fz wafers was irradiated with 23 GeV protons, 200 MeV pions and reactor neutrons up to the equivalent fluences of PHI{sub eq}=3x10{sup 15}cm{sup -2}. The evolution of the full depletion voltage and the leakage current were monitored during short- and long-term annealing. At selected representative annealing steps, charge collection measurements were performed for all samples with LHC speed electronics. Measurements of full depletion voltage, leakage current and charge collection efficiency were compared for different irradiation particles and silicon materials.

Characterization of irradiated APDs for picosecond time measurements

Science.gov (United States)

Centis Vignali, M.; Dalal, R.; Gallinaro, M.; Harrop, B.; Jain, G.; Lu, C.; McClish, M.; McDonald, K. T.; Moll, M.; Newcomer, F. M.; Ugobono, S. Otero; White, S.

2018-01-01

For their operation at the CERN High Luminosity Large Hadron Collider (HL-LHC), the ATLAS and CMS experiments are planning to implement dedicated systems to measure the time of arrival of minimum ionizing particles with an accuracy of about 30 ps. The timing detectors will be subjected to radiation levels corresponding up to a 1-MeV neutrons fluence (Φeq) of 1015 cm-2 for the goal integrated luminosity of HL-LHC of 3000 fb-1. In this paper, deep-diffused Avalanche Photo Diodes (APDs) produced by Radiation Monitoring Devices are examined as candidate timing detectors for HL-LHC applications. These APDs are operated at 1.8 kV, resulting in a gain of up to 500. The timing performance of the detectors is evaluated using a pulsed laser. The effects of radiation damage on current, signal amplitude, noise, and timing performance of the APDs are evaluated using detectors irradiated with neutrons up to Φeq = 1015 cm-2.

High irradiation and ageing properties of resistive Micromegas detectors at the new CERN Gamma Irradiation Facility

CERN Document Server

Andreou, Dimitra

2016-01-01

Resistive Micromegas have been developed in recent years with the aim of making this technology usable in HEP experiments where the high sparking rate of classical Micromegas is not tolerable. A resistive Micromegas with four layers and an active surface of 0.5 m2 each, has been designed and built at CERN as prototype of the detectors to be used for the upgrade of the ATLAS experiment. The detector has been exposed to an intense gamma source of 16 TBq in order to study the effects of ageing and evaluate the detector behavior under high irradiation.

Modifications induced by gamma irradiation to Makrofol polymer nuclear track detector

Directory of Open Access Journals (Sweden)

A. Tayel

2015-03-01

Full Text Available The aim of the present study was extended from obtaining information about the interaction of gamma rays with Makrofol DE 7-2 track detector to introduce the basis that can be used in concerning simple sensor for gamma irradiation and bio-engineering applications. Makrofol polymer samples were irradiated with 1.25 MeV 60Co gamma radiations at doses ranging from 20 to 1000 kG y. The modifications of irradiated samples so induced were analyzed using UV–vis spectrometry, photoluminescence spectroscopy, and the measurements of Vickers’ hardness. Moreover, the change in wettability of irradiated Makrofol was investigated by the contact angle determination of the distilled water. UV–vis spectroscopy shows a noticeable decrease in the energy band gap due to gamma irradiation. This decrease could be attributed to the appearance of a shift to UV spectra toward higher wavelength region after irradiation. Photoluminescence spectra reveal a remarkable change in the integrated photoluminescence intensity with increasing gamma doses, which may be resulted from some matrix disorder through the creation of some defected states in the irradiated polymer. The hardness was found to increase from 4.78 MPa for the unirradiated sample to 23.67 MPa for the highest gamma dose. The contact angle investigations show that the wettability of the modified samples increases with increasing the gamma doses. The result obtained from present investigation furnishes evidence that the gamma irradiations are a successful technique to modify the Makrofol DE 7-2 polymer properties to use it in suitable applications.

Initial Measurements on Pixel Detector Modules for the ATLAS Upgrades

CERN Document Server

Gallrapp, C; The ATLAS collaboration

2011-01-01

Delicate conditions in terms of peak and integrated luminosity in the Large Hadron Collider (LHC) will raise the ATLAS Pixel Detector to its performance limits. Silicon planar, silicon 3D and diamond pixel sensors are three possible sensor technologies which could be implemented in the upcoming Pixel Detector upgrades of the ATLAS experiment. Measurements of the IV-behavior and measurements with radioactive Americium-241 and Strontium-90 are used to characterize the sensor properties and to understand the interaction between the ATLAS FE-I4 front-end chip and the sensor. Comparisons of results from before and after irradiation for silicon planar and 3D pixel sensors, which give a first impression on the charge collection properties of the different sensor technologies, are presented.

Technical Note: Response measurement for select radiation detectors in magnetic fields

Energy Technology Data Exchange (ETDEWEB)

Reynolds, M., E-mail: michaelreynolds@ualberta.net [Department of Oncology, Medical Physics Division, University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada); Fallone, B. G. [Department of Medical Physics, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta T6G 1Z2, Canada and Departments of Oncology and Physics, University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada); Rathee, S. [Department of Medical Physics, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta T6G 1Z2, Canada and Department of Oncology, Medical Physics Division,University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada)

2015-06-15

Purpose: Dose response to applied magnetic fields for ion chambers and solid state detectors has been investigated previously for the anticipated use in linear accelerator–magnetic resonance devices. In this investigation, the authors present the measured response of selected radiation detectors when the magnetic field is applied in the same direction as the radiation beam, i.e., a longitudinal magnetic field, to verify previous simulation only data. Methods: The dose response of a PR06C ion chamber, PTW60003 diamond detector, and IBA PFD diode detector is measured in a longitudinal magnetic field. The detectors are irradiated with buildup caps and their long axes either parallel or perpendicular to the incident photon beam. In each case, the magnetic field dose response is reported as the ratio of detector signals with to that without an applied longitudinal magnetic field. The magnetic field dose response for each unique orientation as a function of magnetic field strength was then compared to the previous simulation only studies. Results: The measured dose response of each detector in longitudinal magnetic fields shows no discernable response up to near 0.21 T. This result was expected and matches the previously published simulation only results, showing no appreciable dose response with magnetic field. Conclusions: Low field longitudinal magnetic fields have been shown to have little or no effect on the dose response of the detectors investigated and further lend credibility to previous simulation only studies.

Diamond detector in absorbed dose measurements in high-energy linear accelerator photon and electron beams.

Science.gov (United States)

Ravichandran, Ramamoorthy; Binukumar, John Pichy; Al Amri, Iqbal; Davis, Cheriyathmanjiyil Antony

2016-03-08

Diamond detectors (DD) are preferred in small field dosimetry of radiation beams because of small dose profile penumbras, better spatial resolution, and tissue-equivalent properties. We investigated a commercially available 'microdiamond' detector in realizing absorbed dose from first principles. A microdiamond detector, type TM 60019 with tandem electrometer is used to measure absorbed doses in water, nylon, and PMMA phantoms. With sensitive volume 0.004 mm3, radius 1.1mm, thickness 1 x10(-3) mm, the nominal response is 1 nC/Gy. It is assumed that the diamond detector could collect total electric charge (nC) developed during irradiation at 0 V bias. We found that dose rate effect is less than 0.7% for changing dose rate by 500 MU/min. The reproducibility in obtaining readings with diamond detector is found to be ± 0.17% (1 SD) (n = 11). The measured absorbed doses for 6 MV and 15 MV photons arrived at using mass energy absorption coefficients and stop-ping power ratios compared well with Nd, water calibrated ion chamber measured absorbed doses within 3% in water, PMMA, and nylon media. The calibration factor obtained for diamond detector confirmed response variation is due to sensitivity due to difference in manufacturing process. For electron beams, we had to apply ratio of electron densities of water to carbon. Our results qualify diamond dosimeter as a transfer standard, based on long-term stability and reproducibility. Based on micro-dimensions, we recommend these detectors for pretreatment dose verifications in small field irradiations like stereotactic treatments with image guidance.

Measurement of neutron sensitivity of self powered neutron detectors

International Nuclear Information System (INIS)

Mahant, A.K.; Yeshuraja, V.; Ghodke, Shobha

2005-01-01

Self powered neutron detectors (SPNDs ) will form the part of Reactor Instrumentation in the upcoming 500 MWe power reactors. ECIL has developed Vanadium and Cobalt SPNDs for NPCIL to be used in regulation and protection channels. Experimental determination of neutron sensitivity of the vanadium and cobalt Self Powered Neutron Detectors (SPNDs) was carried out in A-l location of Apsara reactor at BARC. The measurements involved determination of total detector signal, its various components and the thermal neutron flux at the detector location. The paper describes the experimental techniques used to measure various parameters required to evaluate the neutron sensitivity of the SPNDs and also the parameters required to ascertain the integrity of SPNDs. Neutron flux measurement was done by gold foil irradiation technique. The predominant signal component from the vanadium SPND is Ib the current due to activation of the vanadium emitter, it forms about 85% of the total signal. The other components I n,γ due to the capture gamma rays of 52 V and I externalγ produced by the external reactor gamma rays contribute about 10% and 5% respectively to the total signal. Whereas in the cobalt SPND the main signal component is due to the capture gamma rays of 60 Co and accounts for about the 95% of the total signal. Remaining 5% signal is due to external reactor gamma rays. (author)

Studies on irradiated pixel detectors for the ATLAS IBL and HL-LHC upgrade

Energy Technology Data Exchange (ETDEWEB)

Gallrapp, Christian

2015-07-01

The constant demand for higher luminosity in high energy physics is the reason for the continuous effort to adapt the accelerators and the experiments. The upgrade program for the experiments and the accelerators at CERN already includes several expansion stages of the Large Hadron Collider (LHC) which will increase the luminosity and the energy of the accelerator. Simultaneously the LHC experiments prepare the individual sub-detectors for the increasing demands in the coming years. Especially the tracking detectors have to cope with fluence levels unprecedented for high energy physics experiments. Correspondingly to the fluence increases the impact of the radiation damage which reduces the life time of the detectors by decreasing the detector performance and efficiency. To cope with this effect new and more radiation hard detector concepts become necessary to extend the life time. This work concentrates on the impact of radiation damage on the pixel sensor technologies to be used in the next upgrade of the ATLAS Pixel Detector as well as for applications in the ATLAS Experiment at HL-LHC conditions. The sensors considered in this work include various designs based on silicon and diamond as sensor material. The investigated designs include a planar silicon pixel design currently used in the ATLAS Experiment as well as a 3D pixel design which uses electrodes penetrating the entire sensor material. The diamond designs implement electrodes similar to the design used by the planar technology with diamond sensors made out of single- and poly-crystalline material. To investigate the sensor properties characterization tests are performed before and after irradiation with protons or neutrons. The measurements are used to determine the interaction between the read-out electronics and the sensors to ensure the signal transfer after irradiation. Further tests focus on the sensor performance itself which includes the analysis of the leakage current behavior and the charge

Studies on irradiated pixel detectors for the ATLAS IBL and HL-LHC upgrade

International Nuclear Information System (INIS)

Gallrapp, Christian

2015-01-01

The constant demand for higher luminosity in high energy physics is the reason for the continuous effort to adapt the accelerators and the experiments. The upgrade program for the experiments and the accelerators at CERN already includes several expansion stages of the Large Hadron Collider (LHC) which will increase the luminosity and the energy of the accelerator. Simultaneously the LHC experiments prepare the individual sub-detectors for the increasing demands in the coming years. Especially the tracking detectors have to cope with fluence levels unprecedented for high energy physics experiments. Correspondingly to the fluence increases the impact of the radiation damage which reduces the life time of the detectors by decreasing the detector performance and efficiency. To cope with this effect new and more radiation hard detector concepts become necessary to extend the life time. This work concentrates on the impact of radiation damage on the pixel sensor technologies to be used in the next upgrade of the ATLAS Pixel Detector as well as for applications in the ATLAS Experiment at HL-LHC conditions. The sensors considered in this work include various designs based on silicon and diamond as sensor material. The investigated designs include a planar silicon pixel design currently used in the ATLAS Experiment as well as a 3D pixel design which uses electrodes penetrating the entire sensor material. The diamond designs implement electrodes similar to the design used by the planar technology with diamond sensors made out of single- and poly-crystalline material. To investigate the sensor properties characterization tests are performed before and after irradiation with protons or neutrons. The measurements are used to determine the interaction between the read-out electronics and the sensors to ensure the signal transfer after irradiation. Further tests focus on the sensor performance itself which includes the analysis of the leakage current behavior and the charge

Measurement of spatial dose-rate distribution using a position sensitive detector

International Nuclear Information System (INIS)

Emoto, T.; Torii, T.; Nozaki, T.; Ando, H.

1994-01-01

Recently, the radiation detectors using plastic scintillation fibers (PSF) have been developed to measure the positions exposed to radiation such as neutrons and high energy charged particles. In particular, the time of flight (TOF) method for measuring the difference of time that two directional signals of scintillation light reach both ends of a PSF is a rather simple method for the measurement of the spatial distribution of fast neutron fluence rate. It is possible to use the PSF in nuclear facility working areas because of its flexibility, small diameter and long length. In order to apply TOF method to measure spatial gamma dose rate distribution, the characteristic tests of a detector using PSFs were carried out. First, the resolution of irradiated positions and the counting efficiency were measured with collimated gamma ray. The sensitivity to unit dose rate was also obtained. The measurement of spatial dose rate distribution was also carried out. The sensor is made of ten bundled PSFs, and the experimental setup is described. The experiment and the results are reported. It was found that the PSF detector has the good performance to measure spatial gamma dose rate distribution. (K.I.)

TOSCA simulation of some effects observed in irradiated silicon detectors

International Nuclear Information System (INIS)

Moszczynski, A.S.

2001-12-01

TOSCA package has been used to simulate some effects observed recently in heavily irradiated silicon detectors. In particular, unexpected possibility of α-particle registration at p+ contact has been explained without presented elsewhere assumption that there was p-n junction of unknown origin beneath p+ layer. Performed simulations showed that assumption on relaxation-like character of irradiated silicon material is also not necessary to explain such effects like low-voltage capacitance peak in reverse bias and negative capacitance in forward bias. (author)

Suppression of irradiation effects in gold-doped silicon detectors

International Nuclear Information System (INIS)

McPherson, M.; Sloan, T.; Jones, B.K.

1997-01-01

Two sets of silicon detectors were irradiated with 1 MeV neutrons to different fluences and then characterized. The first batch were ordinary p-i-n photodiodes fabricated from high-resistivity (400 Ω cm) silicon, while the second batch were gold-doped powder diodes fabricated from silicon material initially of low resistivity (20 Ω cm). The increase in reverse leakage current after irradiation was found to be more in the former case than in the latter. The fluence dependence of the capacitance was much more pronounced in the p-i-n diodes than in the gold-doped diodes. Furthermore, photo current generation by optical means was less in the gold doped devices. All these results suggest that gold doping in silicon somewhat suppresses the effects of neutron irradiation. (author)

Beam test results of the irradiated Silicon Drift Detector for ALICE

OpenAIRE

Kushpil, S.; Crescio, E.; Giubellino, P.; Idzik, M.; Kolozhvari, A.; Kushpil, V.; Martinez, M. I.; Mazza, G.; Mazzoni, A.; Meddi, F.; Nouais, D.; Petracek, V.; Piemonte, C.; Rashevsky, A.; Riccati, L.

2005-01-01

The Silicon Drift Detectors will equip two of the six cylindrical layers of high precision position sensitive detectors in the ITS of the ALICE experiment at LHC. In this paper we report the beam test results of a SDD irradiated with 1 GeV electrons. The aim of this test was to verify the radiation tolerance of the device under an electron fluence equivalent to twice particle fluence expected during 10 years of ALICE operation.

Charge collection and space charge distribution in neutron-irradiated epitaxial silicon detectors

International Nuclear Information System (INIS)

Poehlsen, Thomas

2010-04-01

In this work epitaxial n-type silicon diodes with a thickness of 100 μm and 150 μm are investigated. After neutron irradiation with fluences between 10 14 cm -2 and 4 x 10 15 cm -2 annealing studies were performed. CV-IV curves were taken and the depletion voltage was determined for different annealing times. All investigated diodes with neutron fluences greater than 2 x 10 14 cm -2 showed type inversion due to irradiation. Measurements with the transient current technique (TCT) using a pulsed laser were performed to investigate charge collection effects for temperatures of -40 C, -10 C and 20 C. The charge correction method was used to determine the effective trapping time τ eff . Inconsistencies of the results could be explained by assuming field dependent trapping times. A simulation of charge collection could be used to determine the field dependent trapping time τ eff (E) and the space charge distribution in the detector bulk. Assuming a linear field dependence of the trapping times and a linear space charge distribution the data could be described. Indications of charge multiplication were seen in the irradiated 100 μm thick diodes for all investigated fluences at voltages above 800 V. The space charge distribution extracted from TCT measurements was compared to the results of the CV measurements and showed good agreement. (orig.)

The signal shape from the LHCb vertex locator prototype detectors

International Nuclear Information System (INIS)

Charles, M.

2003-01-01

Measurements of the SCT128A ASIC pulse shape, when reading out non-irradiated and irradiated prototype detectors for the LHCb VELO, are presented. The detectors studied were two n-on-n prototype detectors fabricated by Hamamatsu, and a p-on-n prototype detector fabricated by MICRON

Effect of radiation on the electrical properties of plastic detector CR-39

International Nuclear Information System (INIS)

Mahmoud, S.A.; Hamed, A.E.; Abou El-Kier, A.A.; Mousse, M.G.; Kassem, M.E.; El-Shafey, E.M.

1994-01-01

The effect of high alpha-particle fluence on plastic detector CR-39 was studied by measuring the electrical properties of the detector as a function of irradiation dose and frequency using an impedance meter in the frequency range 0.005-500 kHz. When the plastic detector CR-39 is exposed to high irradiation doses, it loses its advantage as a track detector, because of the overlapping of the tracks occurring in the detector at high irradiation fluence. Through the present measurements of dielectric permittivity and conductivity at different frequencies and temperatures, CR-39 could be used as a dosimeter for high irradiation doses

Effect of radiation on the electrical properties of plastic detector CR-39

Energy Technology Data Exchange (ETDEWEB)

Mahmoud, S.A.; Hamed, A.E.; Abou El-Kier, A.A.; Mousse, M.G.; Kassem, M.E.; El-Shafey, E.M. (Physics Department Faculty of Science, Alexandria University, Alexandria (Egypt))

1994-10-15

The effect of high alpha-particle fluence on plastic detector CR-39 was studied by measuring the electrical properties of the detector as a function of irradiation dose and frequency using an impedance meter in the frequency range 0.005-500 kHz. When the plastic detector CR-39 is exposed to high irradiation doses, it loses its advantage as a track detector, because of the overlapping of the tracks occurring in the detector at high irradiation fluence. Through the present measurements of dielectric permittivity and conductivity at different frequencies and temperatures, CR-39 could be used as a dosimeter for high irradiation doses.

ATLAS irradiation studies of n-in-n and p-in-n silicon microstrip detectors

CERN Document Server

Allport, P P; Buttar, C M; Carter, J; Drage, L M; Ferrère, D; Morgan, D; Riedler, P; Robinson, D

1999-01-01

Prior to the module production of the ATLAS silicon microstrip tracker for the barrel and the forward wheels, the characterisation of full-size prototype silicon detectors after radiation to fluences corresponding to 10 years of ATLAS operation is required. The behaviour of p-in-n and n-in-n detectors produced by several manufacturers before and after irradiation to a fluence of 3*10/sup 14/ protons/cm/sup 2/ at the CERN PS facility is discussed. This article summarises some recent results from the ATLAS SCT collaboration. The measurements of leakage current, full depletion voltage, signal-to-noise ratio and charge collection efficiency are presented. Despite the better efficiency performance of n-in-n detectors below depletion, the collaboration chose the p-in-n technology due to its simpler and less costly production since good charge collection efficiencies were achieved at the desired maximum bias voltage. (14 refs).

Charge collection measurements with p-type Magnetic Czochralski silicon single pad detectors

International Nuclear Information System (INIS)

Tosi, C.; Bruzzi, M.; Macchiolo, A.; Scaringella, M.; Petterson, M.K.; Sadrozinski, H.F.-W.; Betancourt, C.; Manna, N.; Creanza, D.; Boscardin, M.; Piemonte, C.; Zorzi, N.; Borrello, L.; Messineo, A.

2007-01-01

The charge collected from beta source particles in single pad detectors produced on p-type Magnetic Czochralski (MCz) silicon wafers has been measured before and after irradiation with 26 MeV protons. After a 1 MeV neutron equivalent fluence of 1x10 15 cm -2 the collected charge is reduced to 77% at bias voltages below 900 V. This result is compared with previous results from charge collection measurements

Opto-structural characterization of gamma irradiated Bayfol polymer track detector

Energy Technology Data Exchange (ETDEWEB)

Tayel, A. [Physics Department, Faculty of Industrial Education, Helwan University, Cairo (Egypt); Zaki, M.F., E-mail: moha1016@yahoo.com [Experimental Nuclear Physics Department, Nuclear Research Center, Atomic Energy Authority, P.O. 13759, Abu Zaabal, Cairo (Egypt); El Basaty, A.B. [Physics Department, Faculty of Industrial Education, Helwan University, Cairo (Egypt); Hegazy, Tarek M. [Physics Department, College of Women for Arts, Science and Education, Ain Shams University, Cairo (Egypt)

2013-11-15

Bayfol CR 1-4 is one of polymeric solid state nuclear track detector which has numerous applications due to its outstanding optical, mechanical, thermal and electrical properties. In the present study, Bayfol polymer is irradiated with different doses of gamma rays ranging from 0 to 1000 KGy. The effects of gamma irradiations on the optical, structural and chemical properties of Bayfol were studied using Ultraviolet and visible (UV/Vis) spectroscopy, X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. The UV–Vis spectra of irradiated samples show that the absorption edge is shifted towards longer wavelength comparing to pristine sample spectrum. This behavior indicates that there is a decrease in the band gap after irradiation. The maximum decrease in the band gap is about 0.8 eV. The XRD patterns of amorphous halo of pristine and irradiated samples show a fluctuation of integrated intensity of amorphous halo. This indicates a change in the structure due to gamma irradiation. In order to understand that structure change mechanism, we used the FTIR spectroscopy.

Radiation Damage in Silicon Detectors Caused by Hadronic and Electromagnetic Irradiation

CERN Document Server

Fretwurst, E.; Stahl, J.; Pintilie, I.

2002-01-01

The report contains various aspects of radiation damage in silicon detectors subjected to high intensity hadron and electromagnetic irradiation. It focuses on improvements for the foreseen LHC applications, employing oxygenation of silicon wafers during detector processing (result from CERN-RD48). An updated survey on hadron induced damage is given in the first article. Several improvements are outlined especially with respect to antiannealing problems associated with detector storage during LHC maintenance periods. Open questions are outlined in the final section, among which are a full understanding of differences found between proton and neutron induced damage, process related effects changing the radiation tolerance in addition to the oxygen content and the lack of understanding the changed detector properties on the basis of damage induced point and cluster defects. In addition to float zone silicon, so far entirely used for detector fabrication,Czochralski silicon was also studied and first promising re...

CCE measurements and annealing studies on proton-irradiated p-type MCz silicon diodes

CERN Document Server

Hoedlmoser, H; Köhler, M; Nordlund, H

2007-01-01

Magnetic Czochralski (MCz) silicon has recently been investigated for the development of radiation tolerant detectors for future high-luminosity HEP experiments. A study of p-type MCz Silicon diodes irradiated with protons up to a fluence of has been performed by means of Charge Collection Efficiency (CCE) measurements as well as standard CV/IV characterizations. The changes of CCE, full depletion voltage and leakage current as a function of fluence are reported. A subsequent annealing study of the irradiated detectors shows an increase in effective doping concentration and a decrease in the leakage current, whereas the CCE remains basically unchanged. Two different series of detectors have been compared differing in the implantation dose of p-spray isolation as well as effective doping concentration (Neff) of the p-type bulk presumably due to a difference in thermal donor (TD) activation during processing. The series with the higher concentration of TDs shows a delayed reverse annealing of Neff after irradia...

Charge collection and space charge distribution in neutron-irradiated epitaxial silicon detectors

Energy Technology Data Exchange (ETDEWEB)

Poehlsen, Thomas

2010-04-15

In this work epitaxial n-type silicon diodes with a thickness of 100 {mu}m and 150 {mu}m are investigated. After neutron irradiation with fluences between 10{sup 14} cm{sup -2} and 4 x 10{sup 15} cm{sup -2} annealing studies were performed. CV-IV curves were taken and the depletion voltage was determined for different annealing times. All investigated diodes with neutron fluences greater than 2 x 10{sup 14} cm{sup -2} showed type inversion due to irradiation. Measurements with the transient current technique (TCT) using a pulsed laser were performed to investigate charge collection effects for temperatures of -40 C, -10 C and 20 C. The charge correction method was used to determine the effective trapping time {tau}{sub eff}. Inconsistencies of the results could be explained by assuming field dependent trapping times. A simulation of charge collection could be used to determine the field dependent trapping time {tau}{sub eff}(E) and the space charge distribution in the detector bulk. Assuming a linear field dependence of the trapping times and a linear space charge distribution the data could be described. Indications of charge multiplication were seen in the irradiated 100 {mu}m thick diodes for all investigated fluences at voltages above 800 V. The space charge distribution extracted from TCT measurements was compared to the results of the CV measurements and showed good agreement. (orig.)

New development in nondestructive measurement and verification of irradiated LWR fuels

International Nuclear Information System (INIS)

Lee, D.M.; Phillips, J.R.; Halbig, J.K.; Hsue, S.T.; Lindquist, L.O.; Ortega, E.M.; Caine, J.C.; Swansen, J.; Kaieda, K.; Dermendjiev, E.

1979-01-01

Nondestructive techniques for characterizing irradiated LWR fuel assemblies are discussed. This includes detection systems that measure the axial activity profile, neutron yield and gamma yield. A multi-element profile monitor has been developed that offers a significant improvement in speed and complexity over existing mechanical scanning systems. New portable detectors and electronics, applicable to safeguard inspection, are presented and results of gamma-ray and neutron measurements at commercial reactor facilities are given

An investigation of methods for neutron dose measurement in high temperature irradiation fields

Energy Technology Data Exchange (ETDEWEB)

Kosako, Toshisou; Sugiura, Nobuyuki [Tokyo Univ. (Japan); Kudo, Kazuhiko [Kyushu Univ., Fukuoka (Japan)] [and others

2000-10-01

The Japan Atomic Energy Research Institute (JAERI) has been conducting the innovative basic research on high temperature since 1994, which is a series of high temperature irradiation studies using the High Temperature Engineering Test Reactor (HTTR). 'The Task Group for Evaluation of Irradiation Dose under High Temperature Radiation' was founded in the HTTR Utilization Research Committee, which is the promoting body of the innovative basic research. The present report is a summary of investigation which has been made by the Task Group on the present status and subjects of research and development of neutron detectors in high temperature irradiation fields, in view of contributing to high temperature irradiation research using the HTTR. Detectors investigated here in the domestic survey are the following five kinds of in-core detectors: 1) small fission counter, 2) small fission chamber, 3) self-powered detector, 4) activation detector, and 5) optical fiber. In addition, the research and development status in Russia has been investigated. The present report will also be useful as nuclear instrumentation of high temperature gas-cooled reactors. (author)

Measurement of Rectal Radiation dose in the Patients with Uterine Cervix fencer using In Vivo Dosimetry(Diode Detector)

International Nuclear Information System (INIS)

Kim, Sung Kee; Kim, Wan Sun

2004-01-01

A rectum and a bladder should be carefully considered in order to decrease side effects when HDR patient of uterine cervix cancer. Generally speaking, the value of dosimeter at a rectum and a bladder only depends on the value of a planning equipment, while some analyses of the value of dosimetry at rectum with TLD has been reported Or the contrary, it is hardly to find a report with in vivo dosimetry(diode detector). On this thesis, we would like to suggest the following. When a patient of uterine cervix cancer is in therapy, it is helpful to put a diode detector inside of a rectum in order to measure the rectal dose Based upon the result of the dosimetry, the result can be used as basic data at decreasing side effects. Six patients of uterine cervix cancer(four with tandem and ovoid, one with cylinder, and the other one with tandem and cylinder) who had been irradiated with HDR. Ir-192 totally 28 times from February 2003 to June 2003. We irradiated twice in the same distant spots with anterior film and lateral film whenever we measured with a diode detector. Then we did planning and compared each film. The result of the measurement 4 patients with a diode detector is the following. The average and deviation from 3 patients with tandem and ovoid were 274±13.4 cGy, from 1 patient with tandem and ovoid were 126.1±7.2 cGy, from 1 patient with cylinder were 99.7±7.1 cGy, and from 1 patient with tandem and cylinder were 77.7±11.5 cGy. It is difficult to predict how the side effect of a rectum since the result of measurement with a diode detector depends on the state of a rectum. According to the result of the study, it is effective to use a TLD or an in vivo dosimetry and measure a rectum in order to consider the side effect. It is very necessary to decrease the amount of irradiation by controlling properly the duration of the irradiation and gauze packing, and by using shield equipment especially when side effects can be expected.

3D detectors at ITC-irst: first irradiation studies

International Nuclear Information System (INIS)

Ronchin, S.; Boscardin, M.; Bosisio, L.; Cindro, V.; Dalla Betta, G.-F.; Piemonte, C.; Pozza, A.; Zoboli, A.; Zorzi, N.

2007-01-01

In the past two years, we have developed 3D detector technologies at ITC-irst (Trento, Italy). We have proposed a new 3D architecture, having columnar electrodes of one doping type only, allowing for a simplified fabrication process. In this paper, we report on preliminary results from the electrical characterization of devices irradiated with neutrons, showing that low depletion voltage values can be achieved even after very large fluences

Scanning of irradiated silicon detectors using $\\alpha$ particles and low energy protons

CERN Document Server

Casse, G L; Glaser, M; Kohout, Z; Konícek, J; Lemeilleur, F; Leroy, C; Linhart, V; Mares, J J; Pospísil, S; Roy, P; Sopko, B; Sinor, M; Svejda, J; Vorobel, V; Wilhelm, I

1999-01-01

In a spectroscopic study of non-irradiated and proton-irradiated silicon diodes, the detectors were illuminated from the front side and from the rear side by various alpha particle sources (mainly ThC') and by monoenergetic protons with energies from 1.0 to 2.5~MeV. Their response characteristics have been studied as a function of the incoming particle energy and the applied bias voltage. The charge collection efficiency was determined as a function of fluence

Noise behaviour of semiinsulating GaAs particle detectors at various temperatures before and after irradiation

International Nuclear Information System (INIS)

Tenbusch, F.; Braunschweig, W.; Chu, Z.; Krais, R.; Kubicki, T.; Luebelsmeyer, K.; Pandoulas, D.; Rente, C.; Syben, O.; Toporowski, M.; Wittmer, B.; Xiao, W.J.

1998-01-01

We investigated the noise behaviour of surface barrier detectors (double sided Schottky contact) made of semiinsulating GaAs. Two types of measurements were performed: equivalent noise charge (ENC) and noise power density spectra in a frequency range from 10 Hz to 500 kHz. The shape of the density spectra are a powerful tool to examine the physical origin of the noise, before irradiation it is dominated by generation-recombination processes caused by deep levels. Temperature dependent noise measurements reveal the deep level parameters like activation energy and cross section, which are also extracted by analyzing the time transients of the charge pulse from α-particles. After irradiation with protons, neutrons and pions the influence of the deep levels being originally responsible for the noise is found to decrease and a reduction of the noise over the entire frequency range with increasing fluence is observed. (orig.)

Solar irradiance measurements from the Danish Galathea 3 expedition

Energy Technology Data Exchange (ETDEWEB)

Bason, Frank [SolData Instruments, Silkeborg (Denmark)

2008-07-01

The Danish Galathea 3 Expedition completed an eight month journey of exploration and discovery on April 25th, 2007, having set sail from Copenhagen on August 11th, 2006. SolData Instruments was privileged to be selected to contribute an ''optics table'' with pyranometers, ultraviolet, lux, sky luminance, PAR and other optical radiation detectors. These instruments recorded data continuously during the 100.000 kilometer voyage of the Royal Danish Navy vessel Vaedderen. The voyage provided global solar irradiance and other data as far north as the Arctic Circle near Greenland and as far south as Antarctica. The data collected was analyzed to validate a solar irradiance model described in this paper. A unique opportunity was also provided to check the performance of SolData photovoltaic pyranometers against data from a Kipp-Zonen CMll instrument. In addition to optical radiation, ionizing radiation and atmospheric pressure were also measured, and some interesting aspects of these measurements will also be mentioned. (orig.)

Gamma irradiation effects on the thermal, optical and structural properties of Cr-39 nuclear track detector

International Nuclear Information System (INIS)

Nouh, S.A.; Said, A.F.; Atta, M.R.; EL-Mellegy, W.M.; EL-Meniawi, S.

2006-01-01

A study of the effect of gamma irradiation on the thermal, optical and structural properties of CR-39 diglycol carbonate solid state nuclear track detector (SSNTD) has been carried out. Samples from CR-39 polymer were irradiated with gamma doses at levels between 20 and 300 KGy. Non-isothermal studies were carried out using thermo-gravimetry (TG), differential thermo-gravimetry (DTG) and differential thermal analysis (DTA) to obtain the activation energy of decomposition and the transition temperatures for the non-irradiated and irradiated CR-39 samples. In addition, optical and structural property studies were performed on non-irradiated and irradiated CR-39 samples using refractive index and X-ray diffraction measurements. The variation of onset temperature of decomposition (To) thermal activation energy of decomposition (Ea) melting temperature (Tm) refractive index (n) and the mass fraction of the amorphous phase with the gamma dose were studied. It was found that many changes in the thermal, optical and structural properties of the CR-39 polymer could be produced by gamma irradiation via the degradation and cross linking mechanisms. Also, the gamma dose gave an advantage for increasing the correlation between the thermal stability of CR-39 polymer and the bond formation created by the ionizing effect of gamma radiation

Neutron irradiation effects on silicon detectors structure, electrical and mechanical characteristics

International Nuclear Information System (INIS)

Rabinovich, E.; Golan, G.; Axelevich, A.; Inberg, A.; Oksman, M.; Rosenwaks, I.; Lubarsky, G.; Seidman, A.; Croitoru, N.; Rancoita, P.G.; Rattaggi, M.

1999-01-01

Neutron irradiation effects on (p-n) and Schottky-junction silicon detectors were studied. It was shown that neutron interactions with monocrystalline silicon create specific types of microstructure defects with morphology differing according to the level of neutron fluences (Φ). The isolated dislocation loops, formed by interstitial atoms were observed in microstructure images for 10 10 ≤ Φ ≤ 10 12 n/cm 2 . A strong change in the dislocation loops density and a cluster formation was observed for Φ ≥ 10 13 n/cm 2 . A drastic silicon damage was found for fluences over 10 14 n/cm 2 . These fluences created zones enriched with all types of dislocations, covering more than 50 % of the total surface area. A mechanical fragility appeared in that fluence range in a form of microcracks. 10 14 n/cm 2 appears to be a critical value of neutron irradiation because of the radiation damage described above and because the characteristics I f -V f of silicon detectors can be differentiated from those obtained at low fluences. (A.C.)

ENC Measurement for ASIC Preamp Board as a Detector Module for PET System

Directory of Open Access Journals (Sweden)

N. Nagara

2016-08-01

Full Text Available We developed a gamma ray detector with an LuAG:Pr scintillator and an avalanche photodiode as a detector for a positron emission tomography (PET system. Studies have been performed on the influences of gamma irradiation on application-specific integrated circuit (ASIC preamp boards used as a detector module. As a device used in nuclear environments for substantial durations, the ASIC has to have a lifetime long enough to ensure that there will be a negligible failure rate during this period. These front-end systems must meet the requirements for standard positron emission tomography (PET systems. Therefore, an equivalent noise charge (ENC experiment is needed to measure the front-end system's characteristics. This study showed that minimum ENC conditions can be achieved if a shorter shaping time could be applied.

The results of the irradiations of microstrip detectors for the ATLAS tracker (SCT)

International Nuclear Information System (INIS)

Dervan, P.J.

2003-01-01

The SemiConductor Tracker (SCT) of ATLAS will operate in the Large Hadron Collider (LHC) at CERN, which will reach luminosities of 10 34 cm 2 s -1 . Silicon single-sided microstrip detectors will be used for particle tracking. Due to the proximity to the beam, the silicon detectors need to withstand damage from ionising radiation (10 Mrad total dose) and from non-ionising radiation such as neutrons (2x10 14 1 MeV equivalent neutrons/cm 2 total fluence). The final characteristics of the silicon SCT detectors which are needed to operate under LHC conditions and the conclusions reached after various years of test irradiation studies will be reported. The integration and performance of these detectors in complete SCT modules is also discussed

Sensitivity Measurement of a long SPND by a Split Neutron Irradiation

International Nuclear Information System (INIS)

Choi, Young San; Park, Sang Jun; Jung, Hwan Sung

2006-01-01

A Self Powered neutron Detector (SPND) has been used effectively as an in-core neutron monitor for a long time both in nuclear research reactors and power reactors due to its very simple dimensions and structures. For power reactor applications, Rhodium, Vanadium, Platinum, and Silver are usually used as the typical emitter materials for the SPNDs. The SPNDs with a Rhodium emitter (Rh-SPNDs) are most frequently used at Korean Standard Nuclear Power stations (KSNP) as a fixed incore neutron detector. This paper describes a new method to measure the neutron sensitivity of the Rh-SPNDs with a long sensitive length at a horizontal beam tube of HANARO by a split irradiation of them

Measurement of energy deposition distributions produced in cylindrical geometry by irradiation with 15 MeV neutrons

International Nuclear Information System (INIS)

Brandan, M.E.

1979-01-01

Cellular survival experiments have shown that the biological damage induced by radiation depends on the density of energy deposition along the trajectory of the ionizing particle. The quantity L is defined to measure the density of energy transfer along a charged particle's trajectory. It is equal to sigma/l, where sigma is the energy transferred to a medium and l is the path length along which the transfer takes place. L is the stochastic quantity whose mean value is the unrestricted linear energy transfer, L/sub infinity/. Measurements of the distribution of L in a thin medium by secondary charged particles from fast neutron irradiation were undertaken. A counter operating under time coincidence between two coaxial cylindrical detectors was designed and built for this purpose. Secondary charged particles enter a gas proportional counter and deposit some energy sigma. Those particles traversing the chamber along a radial trajectory strike a CsI scintillator. A coincidence between both detectors' signals selects a known path length for these events, namely the radius of the cavity. Measurements of L distributions for l = 1 μm in tissue were obtained for 3 and 15 MeV neutron irradiation of a tissue-equivalent target wall and for 15 MeV neutron irradiation of a graphite wall. Photon events were corrected for by measurements with a Pb target wall and 15 MeV neutron irradiation as well as exposure to a pure photon field. The measured TE wall distributions with 15 MeV neutron bombardment show contributions from protons, α-particles, 9 Be and 12 C recoils. The last three comprise the L distribution for irradiation of the graphite wall. The proton component of the measured L distributions at 3 and 15 MeV was compared to calculated LET distributions

Single track coincidence measurements of fluorescent and plastic nuclear track detectors in therapeutic carbon beams

International Nuclear Information System (INIS)

Osinga, J-M; Jäkel, O; Ambrožová, I; Brabcová, K Pachnerová; Davídková, M; Akselrod, M S; Greilich, S

2014-01-01

In this paper we present a method for single track coincidence measurements using two different track detector materials. We employed plastic and fluorescent nuclear track detectors (PNTDs and FNTDs) in the entrance channel of a monoenergetic carbon ion beam covering the therapeutic energy range from 80 to 425 MeV/u. About 99% of all primary particle tracks detected by both detectors were successfully matched, while 1% of the particles were only detected by the FNTDs because of their superior spatial resolution. We conclude that both PNTDs and FNTDs are suitable for clinical carbon beam dosimetry with a detection efficiency of at least 98.82% and 99.83% respectively, if irradiations are performed with low fluence in the entrance channel of the ion beam. The investigated method can be adapted to other nuclear track detectors and offers the possibility to characterize new track detector materials against well-known detectors. Further, by combining two detectors with a restricted working range in the presented way a hybrid-detector system can be created with an extended and optimized working range

Self-Powered Neutron Detector Qualification for Absolute On-Line In-Pile Neutron Flux Measurements in BR2

Science.gov (United States)

Vermeeren, L.; Wéber, M.

2003-06-01

A set of ten Self-Powered Neutron Detectors with Co, Rh and Ag emitters has been irradiated in several channels of the BR2 research reactor at SCK•CEN aiming at a comparison of their performance as thermal neutron flux detectors under various conditions. To allow for a correct interpretation of their signals, all detector sensitivity contributions (prompt and delayed) were calculated using a dedicated Monte Carlo model. The various contributions were also measured separately; the agreement between calculated and experimental data, including data from activation dosimetry, was excellent. Detailed neutron flux profiles were obtained from the SPND data, after correction for the finite detector lengths and for the slow response of delayed SPNDs.

Output factor determination for dose measurements in axial and perpendicular planes using a silicon strip detector

Science.gov (United States)

Abou-Haïdar, Z.; Bocci, A.; Alvarez, M. A. G.; Espino, J. M.; Gallardo, M. I.; Cortés-Giraldo, M. A.; Ovejero, M. C.; Quesada, J. M.; Arráns, R.; Prieto, M. Ruiz; Vega-Leal, A. Pérez; Nieto, F. J. Pérez

2012-04-01

In this work we present the output factor measurements of a clinical linear accelerator using a silicon strip detector coupled to a new system for complex radiation therapy treatment verification. The objective of these measurements is to validate the system we built for treatment verification. The measurements were performed at the Virgin Macarena University Hospital in Seville. Irradiations were carried out with a Siemens ONCOR™ linac used to deliver radiotherapy treatment for cancer patients. The linac was operating in 6 MV photon mode; the different sizes of the fields were defined with the collimation system provided within the accelerator head. The output factor was measured with the silicon strip detector in two different layouts using two phantoms. In the first, the active area of the detector was placed perpendicular to the beam axis. In the second, the innovation consisted of a cylindrical phantom where the detector was placed in an axial plane with respect to the beam. The measured data were compared with data given by a commercial treatment planning system. Results were shown to be in a very good agreement between the compared set of data.

Measurement and evaluation of fast neutron flux of CT and OR5 irradiation hole in HANARO

International Nuclear Information System (INIS)

Yang, Seong Woo; Choo, Kee Nam; Lee, Seung-Kyu; Kim, Yong Kyun

2012-01-01

The irradiation test has been conducted to evaluate the irradiation performance of many materials by a material capsule at HANARO. Since the fast neutron fluence above 1 MeV is important for the irradiation test of material, it must be measured and evaluated exactly at each irradiation hole. Therefore, a fast neutron flux was measured and evaluated by a 09M-02K capsule irradiated in an OR5 irradiation hole and a 10M-01K capsule irradiated in a CT irradiation hole. Fe, Ni, and Ti wires as the fluence monitor were used for the detection of fast neutron flux. Before the irradiation test, the neutron flux and spectrum was calculated for each irradiation hole using an MCNP code. After the irradiation test, the activity of the fluence monitor was measured by an HPGe detector and the reaction rate was calculated. For the OR5 irradiation hole, the radial difference of the fast neutron flux was observed from a calculated data due to the OR5 irradiation hole being located outside the core. Furthermore, a control absorber rod was withdrawn from the core as the increase of the irradiation time at the same irradiation cycle, so the distribution of neutron flux was changed from the beginning to the end of the cycle. These effects were considered to evaluate the fast neutron flux. Neutron spectrums of the CT and OR5 irradiation hole were adjusted by the measured data. The fluxes of a fast neutron above 1 MeV were compared with calculated and measured value. Although the maximum difference was shown at 18.48%, most of the results showed good agreement. (author)

Radiation hardness of silicon detectors manufactured on wafers from various sources

International Nuclear Information System (INIS)

Dezillie, B.; Bates, S.; Glaser, M.; Lemeilleur, F.; Leroy, C.

1997-01-01

Impurity concentrations in the initial silicon material are expected to play an important role for the radiation hardness of silicon detectors, during their irradiation and for their evolution with time after irradiation. This work reports on the experimental results obtained with detectors manufactured using various float-zone (FZ) and epitaxial-grown material. Preliminary results comparing the changes in leakage current and full depletion voltage of FZ and epitaxial detectors as a function of fluence and of time after 10 14 cm -2 proton irradiation are given. The measurement of charge collection efficiency for epitaxial detectors is also presented. (orig.)

Charge collection efficiency and resolution of an irradiated double-sided silicon microstrip detector operated at cryogenic temperatures

International Nuclear Information System (INIS)

Borer, K.; Janos, S.; Palmieri, V.G.; Buytaert, J.; Chabaud, V.; Chochula, P.; Collins, P.; Dijkstra, H.; Niinikoski, T.O.; Lourenco, C.; Parkes, C.; Saladino, S.; Ruf, T.; Granata, V.; Pagano, S.; Vitobello, F.; Bell, W.; Bartalini, P.; Dormond, O.; Frei, R.; Casagrande, L.; Bowcock, T.; Barnett, I.B.M.; Da Via, C.; Konorov, I.; Paul, S.; Schmitt, L.; Ruggiero, G.; Stavitski, I.; Esposito, A.

2000-01-01

This paper presents results on the measurement of the cluster shapes, resolution and charge collection efficiency of a double-sided silicon microstrip detector after irradiation with 24 GeV protons to a fluence of 3.5x10 14 p/cm 2 and operated at cryogenic temperatures. An empirical model is presented which describes the expected cluster shapes as a function of depletion depth, and is shown to agree with the data. It is observed that the clusters on the p-side broaden if the detector is under-depleted, leading to a degradation of resolution and efficiency. The model is used to make predictions for detector types envisaged for the LHC experiments. The results also show that at cryogenic temperature the charge collection efficiency varies depending on the operating conditions of the detector and can reach values of 100% at unexpectedly low bias voltage. By analysing the cluster shapes it is shown that these variations are due to changes in depletion depth. This phenomenon, known as the 'Lazarus effect', can be related to similar recent observations on diode behaviour

The influence of fast neutron irradiation on the noise properties of silicon surface-barrier detectors

International Nuclear Information System (INIS)

Dabrowski, W.; Korbel, K.

1988-01-01

The susceptibility to the fast neutron irradiation of silicon surface-barrier detectors has been investigated. It was shown that the 1/f-noise decreases substantially with increasing fluence in the range from 10 10 n/cm 2 to 10 11 n/cm 2 . The deterioration of the detector performance is caused mainly by the positively-charged defects induced by the radiation. The critical value of the neutron fluence, at which the detector performance begins to be worsened was also determined. 5 refs., 5 figs. (author)

Thermal Module Tests with Irradiated 070 Detectors.

CERN Document Server

HOWCROFT, C L F

1998-01-01

Four n-in-n detectors were irradiated at KEK to a fluence of 3*1014 protons cm-2. These were used to construct a thermal barrel module to 070 drawings with an A3-90 baseboard at the Rutherford Appleton Laboratory. Thermal testes were conducted on the module, examining the runaway point and the temperatures across the silicon. The results obtained were used to calculate the runaway point under ATLAS conditions. It was concluded that this module meets the specifications in the Technical Design Report, of 160 mW mm-2@ 0°C for runaway and less than 5°C across the silicon. The module was also compared to a Finite Element Analysis, and showed a good agreement.

Measurements of the reverse current of highly irradiated silicon sensors to determine the effective energy and current related damage rate

Science.gov (United States)

Wiehe, Moritz; Wonsak, S.; Kuehn, S.; Parzefall, U.; Casse, G.

2018-01-01

The reverse current of irradiated silicon sensors leads to self heating of the sensor and degrades the signal to noise ratio of a detector. Precise knowledge of the expected reverse current during detector operation is crucial for planning and running experiments in High Energy Physics. The dependence of the reverse current on sensor temperature and irradiation fluence is parametrized by the effective energy and the current related damage rate, respectively. In this study 18 n-in-p mini silicon strip sensors from companies Hamamatsu Photonics and Micron Semiconductor Ltd. were deployed. Measurements of the reverse current for different bias voltages were performed at temperatures of -32 ° C, -27 ° C and -23 ° C. The sensors were irradiated with reactor neutrons in Ljubljana to fluences ranging from 2 × 1014neq /cm2 to 2 × 1016neq /cm2. The measurements were performed directly after irradiation and after 10 and 30 days of room temperature annealing. The aim of the study presented in this paper is to investigate the reverse current of silicon sensors for high fluences of up to 2 × 1016neq /cm2 and compare the measurements to the parametrization models.

The two sides of silicon detectors

International Nuclear Information System (INIS)

Devine, S.R.

2001-10-01

Results are presented on in situ irradiation of silicon detector's at cryogenic temperature. The results show that irradiation at cryogenic temperatures does not detrimentally effect a silicon detectors performance when compared to its irradiation at room temperature. Operation of silicon devices at cryogenic temperatures offers the advantage of reducing radiation-induced leakage current to levels of a few pA, while at 130K the Lazarus Effect plays an important role i.e. minimum voltage required for full depletion. Performing voltage scans on a 'standard' silicon pad detector pre- and post annealing, the charge collection efficiency was found to be 60% at 200V and 95% at 200V respectively. Time dependence measurements are presented, showing that for a dose of 6.5x10 14 p/cm 2 (450GeV protons) the time dependence of the charge collection efficiency is negligible. However, for higher doses, 1.2x10 15 p/cm 2 , the charge collection efficiency drops from an initial measured value of 67% to a stable value of 58% over a period of 15 minutes for reversed biased diodes. An analysis of the 'double junction' effect is also presented. A comparison between the Transient Current Technique and an X-ray technique is presented. The double junction has been observed in p + /n/n + silicon detectors after irradiation beyond 'type inversion', corresponding to a fluence equivalent to ∼3x10 13 cm -2 1MeV neutrons, producing p + /p/n + and essentially two p-n junctions within one device. With increasing bias voltage, as the electric field is extending into the detector bulk from opposite sides of the silicon detector, there are two distinct depletion regions that collect charge signal independently. Summing the signal charge from the two regions, one is able to reconstruct the initial energy of the incident particle. From Transient Current measurements it is apparent that E-field manipulation is possible by excess carrier injection, enabling a high enough E-field to extend across the

Power measurement in the boiling capsules in R2 using delayed neutron detector

International Nuclear Information System (INIS)

Roennberg, G.

1979-03-01

LWR fuel testing is performed in the R2 reactor by irradiation in both loops and so-called boiling capsules. The loops have forced cooling, and the power can be measured calorimetrically by conventional instrumentation. The boiling capsules have convection cooling, and it has therefore been necessary to develop a special technique for power measurement, the delayed neutron detector (DND). The DND is a pneumatic rabbit system, which activates small uranium samples in the boiling capsules and counts the delayed neutrons for determination of the fission rate. This report describes the equipment used, the procedure of measurement, and the method of evaluation. (atuhor)

Radiation tolerance of oxygenated n-strip read-out detectors

CERN Document Server

Allport, P P; Greenall, A

2003-01-01

Following earlier work on 'oxygenated' detectors in terms of charge collection efficiencies after proton irradiation, full-size detectors for the LHC have been processed with n-side read-out on oxygen enhanced n-type silicon substrates. Two hundred-micron-thick detectors have been inhomogeneously irradiated up to doses of 7 multiplied by 10**1**4p/cm**2 using 24 GeV protons from the CERN PS. Results are presented on the charge collection efficiencies as a function of operating voltage for regions of the detectors irradiated to different doses, using LHC speed analogue read-out electronics. The measurements confirm the expectations which led to our original proposal of such detectors which are now being envisaged for the silicon-based detector systems at the LHC designed to withstand the greatest doses. The possibilities for survival at an upgraded luminosity LHC (Super-LHC) are also briefly discussed.

Radiation-damage studies, irradiations and high-dose dosimetry for LHC detectors

CERN Document Server

Coninckx, F; León-Florián, E; Leutz, H; Schönbacher, Helmut; Sonderegger, P; Tavlet, Marc; Sopko, B; Henschel, H; Schmidt, H U; Boden, A; Bräunig, D; Wulf, F; Cramariuc, R; Ilie, D; Fattibene, P; Onori, S; Miljanic, S; Paic, G; Razen, B; Razem, D; Rendic, D; CERN. Geneva. Detector Research and Development Committee

1991-01-01

The proposal is divided into a main project and special projects. The main project consists of a service similar to the one given in the past to accelerator construction projects at CERN (ISR,SPS,LEP) on high-dose dosimetry, material irradiations, irradiations tests, standardization of test procedures and data compilations. Large experience in this field and numerous radiation damage test data of insulating and structural materials are available. The special projects cover three topics which are of specific interest for LHC detector physicists and engineers at CERN and in other high energy physics institutes, namely: Radiation effects in scintillators; Selection of radiation hard optical fibres for data transmission; and Selection and testing of radiation hard electronic components.

Measurement of accelerator-based neutron distributions using nuclear track detectors

International Nuclear Information System (INIS)

Al-Jarallah, M.I.; Abu-Jarad, F.; Rehman, Fazal-ur-; Khiari, F.Z.; Aksoy, A.; Nassar, R.

2000-01-01

Nuclear track detectors were used to measure the longitudinal and transverse distributions of slow neutrons in a moderated neutron field as well as the longitudinal and transverse distributions of fast neutrons produced on the 0 deg. beam line of the KFUPM 350 keV ion accelerator. The neutrons were first produced from the T(d,n) 4 He reaction with a neutron energy of approximately 14 MeV and were then moderated in a cylindrical polyethylene moderator placed at the end of the 0 deg. beam line. The optimal transverse slow neutron distribution was found to be uniform within ±4.5% at a 3 cm depth inside the moderator. The fast neutron distribution component along the moderator central axis exhibited an exponential-like drop in intensity with depth. Linearity checks of alpha and proton recoil track density with irradiation time for the nuclear track detectors were verified for both slow and fast neutrons

Measurement of accelerator-based neutron distributions using nuclear track detectors

Energy Technology Data Exchange (ETDEWEB)

Al-Jarallah, M.I. E-mail: mibrahim@kfupm.edu.sa; Abu-Jarad, F.; Rehman, Fazal-ur-; Khiari, F.Z.; Aksoy, A.; Nassar, R

2000-12-01

Nuclear track detectors were used to measure the longitudinal and transverse distributions of slow neutrons in a moderated neutron field as well as the longitudinal and transverse distributions of fast neutrons produced on the 0 deg. beam line of the KFUPM 350 keV ion accelerator. The neutrons were first produced from the T(d,n){sup 4}He reaction with a neutron energy of approximately 14 MeV and were then moderated in a cylindrical polyethylene moderator placed at the end of the 0 deg. beam line. The optimal transverse slow neutron distribution was found to be uniform within {+-}4.5% at a 3 cm depth inside the moderator. The fast neutron distribution component along the moderator central axis exhibited an exponential-like drop in intensity with depth. Linearity checks of alpha and proton recoil track density with irradiation time for the nuclear track detectors were verified for both slow and fast neutrons.

Radiation damage in barium fluoride detector materials

International Nuclear Information System (INIS)

Levey, P.W.; Kierstead, J.A.; Woody, C.L.

1988-01-01

To develop radiation hard detectors, particularly for high energy physics studies, radiation damage is being studied in BaF 2 , both undoped and doped with La, Ce, Nd, Eu, Gd and Tm. Some dopants reduce radiation damage. In La doped BaF 2 they reduce the unwanted long lifetime luminescence which interferes with the short-lived fluorescence used to detect particles. Radiation induced coloring is being studied with facilities for making optical measurements before, during and after irradiation with 60 C0 gamma rays. Doses of 10 6 rad, or less, create only ionization induced charge transfer effects since lattice atom displacement damage is negligible at these doses. All crystals studied exhibit color center formation, between approximately 200 and 800 nm, during irradiation and color center decay after irradiation. Thus only measurements made during irradiation show the total absorption present in a radiation field. Both undoped and La doped BaF 2 develop damage at minimum detectable levels in the UV---which is important for particle detectors. For particle detector applications these studies must be extended to high dose irradiations with particles energetic enough to cause lattice atom displacement damage. In principle, the reduction in damage provided by dopants could apply to other applications requiring radiation damage resistant materials

Is the Spencer-Attix cavity equation applicable for solid-state detectors irradiated in megavoltage electron beams?

International Nuclear Information System (INIS)

Mobit, P.N.; Sandison, G.A.; Calgary Univ., AB

2001-01-01

The applicability of the Spencer-Attix cavity equation in determining absorbed doses in water using solid state detectors irradiated by megavoltage electron beams have been examined. The calculations were performed using the EGSnrc Monte Carlo code. This work is an extension of a recently published article examining the perturbation of dose by solid state detectors in megavoltage electron beams. (orig.)

Cherenkov Detector for Beam Quality Measurement

CERN Document Server

AUTHOR|(CDS)2078842

2016-01-01

A new detector to measure the machine induced background at larger radiihas been developed and installed in the CMS experiment at LHC. Itconsists of 40 modules, each comprising a quartz bar read out by aphotomultiplier. Since Cerenkov radiation is emitted in a forward conearound the charged particle trajectory, these detectors can distinguishthe directions of the machine induced background.The back-end consists of a microTCA readout with excellent time resolution.The performance of the detector modules measured in several test-beamcampaigns will be reported. The installation in CMS will be described, andfirst results about operating the detector during data taking will begiven.

Measuring depths of sub-micron tracks in a CR-39 detector from replicas using Atomic Force Microscopy

International Nuclear Information System (INIS)

Yu, K.N.; Ng, F.M.F.; Nikezic, D.

2005-01-01

One of the challenging tasks in the application of solid-state nuclear track detectors (SSNTDs) is the measurement of the depth of the tracks, in particular, the shallow ones resulting from short etching periods. In the present work, a method is proposed to prepare replicas of tracks from α particles in the CR-39 SSNTDs and to measure their heights using atomic force microscopy (AFM). After irradiation, the detectors were etched in a 6.25N aqueous solution of NaOH maintained at 70 deg. C. The etched detectors were immersed into a beaker of the replicating fluid, which was placed in a water bath under ultrasonic vibration and maintained at room temperature to facilitate the filling of the etched tracks with the replicating fluid. As an example of application, these results have been used to derive a V function for the CR-39 detectors used in the present study (for the specified etching conditions)

Study of gamma irradiation effects on the etching and optical properties of CR-39 solid state nuclear track detector and its application to uranium assay in soil samples

International Nuclear Information System (INIS)

Amol Mhatre; Kalsi, P.C.

2011-01-01

The gamma irradiation effects in the dose range of 2.5-43.0 Mrad on the etching and optical characteristics of CR-39 solid state nuclear track detector (SSNTD) have been studied by using etching and UV-Visible spectroscopic techniques. From the measured bulk etch rates at different temperatures, the activation energies for bulk etching at different doses have also been determined. It is seen that the bulk etch rates increase and the activation energies for bulk etching decrease with the increase in gamma dose. The optical band gaps of the unirradiated and the gamma -irradiated detectors determined from the UV-Visible spectra were found to decrease with the increase in gamma dose. These results have been explained on the basis of scission of the detector due to gamma irradiation. The present studies can be used for the estimation of gamma dose in the range of 2.5-43.0 Mrad and can also be used for estimating track registration efficiency in the presence of gamma dose. The CR-39 detector has also been applied for the assay of uranium in some soil samples of Jammu city. (author)

Neutron measurement in 12,13C+ 27Al system using CR-39 detectors and neutron rem meter

International Nuclear Information System (INIS)

Sahoo, G.S.; Tripathy, S.P.; Shanbhag, A.A.; Sunil, C.; Joshi, D.S.; Sarkar, P.K.

2011-01-01

In this work, neutron measurements carried out for the interaction of 60 and 67.5 MeV 12 C, 57.3 and 65 MeV 13 C ions with thick aluminium target by using CR-39 detectors and neutron rem meter is reported. Both the detector systems were irradiated at different angles viz. 0 deg, 30 deg, 60 deg, 90 deg with respect to the beam direction. The normalized track density measurements (tracks/cm 2 /projectile at 1m) in CR-39 detectors were correlated with the normalized dose equivalent values (μSv/projectile at 1m) obtained using the neutron rem meter. The track density was found to be more in case of 13 C than 12 C. However in all the cases, the track density per incident projectile was found to decrease as the angle with respect to beam direction increases, indicating non-isotropic nature of neutron emission. The ratio between measured dose equivalent in rem meter to the measured track densities in CR-39 detectors was found to be 2.8±0.2, which remains constant irrespective of the change in angle from beam direction as well as neutron spectrum, indicating a flat dose response of CR-39 detectors. (author)

Ion smoke detector

International Nuclear Information System (INIS)

Basset, Georges.

1976-01-01

This invention covers an ion smoke detector in which the capacity that the smoke will cross, in the event of an accident, is irradiated by a very low energy radioactive source. The gas in the containment is thus partially ionised. Smoke in this containment reduces the mobility of the ions, thereby increasing the impedance of the measuring chamber. A leak tight reference chamber that therefore receives no smoke is added to the measuring chamber. This chamber is filled with the same gas as that present in the measuring chamber and undergoes the same irradiation. It is of course subjected to the same conditions of temperature, atmospheric pressure and hygrometry as the measuring chamber. This makes it possible to break free from the fluctuations of the impedance of the chamber which would seem to be due to these interferences. One only radioactive source irradiates the measuring chamber and the reference chamber. The measuring chamber is in the shape of a cylinder open at one end and the reference chamber is annular and encompasses the measuring chamber. Provision is made for detecting an increase in the potential across the terminals of the measuring chamber in relation to the reference chamber, which is characteristic of the presence of smoke and other provisions separate from the former for dectecting a reduction in potential between the electrodes of the first ionisation chamber, which is characteristic of a change in the detector [fr

Collected charge and Lorentz angle measurement on non-irradiated ATLAS silicon micro-strip sensors for the HL-LHC

Energy Technology Data Exchange (ETDEWEB)

Yildirim, Eda

2017-02-15

In this thesis, the collected charge and the Lorentz angle on non-irradiated and the irradiated miniature of the current test silicon micro-strip sensors (ATLAS12) of the future ATLAS inner tracker are measured. The samples are irradiated up to 5 x 10{sup 15} 1 MeV n{sub eq}/cm{sup 2} and some of them also measured after short-term annealing (80 min at 60 C). The measurements are performed at the DESY II test beam, which provides the advantage of tracking to suppress noise hits. The collected charge is measured at various bias voltages for each sample. The results are compared with the measurements performed using a Sr{sup 90} radioactive source. It is shown that the measurements with beam and radioactive source are consistent with each other, and the advantage of tracking at the beam measurements provides the measurement of collected charge on highly irradiated sensors at lower bias voltages. The Lorentz angle is measured for each sample at different magnetic field strengths between 0 T and 1 T, the results are extrapolated to 2 T, which is the magnetic field in the inner tracker of the ATLAS detector. Most of the measurements are performed at -500 V bias voltage, which is the planned operation bias voltage of the future strip tracker. Some samples are also measured at different bias voltages to observe the effect of bias voltage on the Lorentz angle. The signal reconstruction of the strip sensors are performed using the lowest possible signal-to-noise thresholds. For non-irradiated samples, the measured Lorentz angle agrees with the prediction of the BFK model. On the irradiated samples, the results suggest that the Lorentz angle decreases with increasing bias voltage due to the increasing electric field in the sensor. The Lorentz angle decreases with increasing irradiation level; however, if the sample is under-depleted, the effect of electric field dominates and the Lorentz angle increases. Once the irradiation level becomes too high, hence the collected charge

Measurement and calculation of characteristic prompt gamma ray spectra emitted during proton irradiation

Energy Technology Data Exchange (ETDEWEB)

Polf, J C; Peterson, S; Beddar, S [M D Anderson Cancer Center, Univeristy of Texas, Houston, TX 77030 (United States); McCleskey, M; Roeder, B T; Spiridon, A; Trache, L [Cyclotron Institute, Texas A and M University, College Station, TX 77843 (United States)], E-mail: jcpolf@mdanderson.org

2009-11-21

In this paper, we present results of initial measurements and calculations of prompt gamma ray spectra (produced by proton-nucleus interactions) emitted from tissue equivalent phantoms during irradiations with proton beams. Measurements of prompt gamma ray spectra were made using a high-purity germanium detector shielded either with lead (passive shielding), or a Compton suppression system (active shielding). Calculations of the spectra were performed using a model of both the passive and active shielding experimental setups developed using the Geant4 Monte Carlo toolkit. From the measured spectra it was shown that it is possible to distinguish the characteristic emission lines from the major elemental constituent atoms (C, O, Ca) in the irradiated phantoms during delivery of proton doses similar to those delivered during patient treatment. Also, the Monte Carlo spectra were found to be in very good agreement with the measured spectra providing an initial validation of our model for use in further studies of prompt gamma ray emission during proton therapy. (note)

Luminosity Measurements with the ATLAS Detector

CERN Document Server

Maettig, Stefan; Pauly, T

For almost all measurements performed at the Large Hadron Collider (LHC) one crucial ingredient is the precise knowledge about the integrated luminosity. The determination and precision on the integrated luminosity has direct implications on any cross-section measurement, and its instantaneous measurement gives important feedback on the conditions at the experimental insertions and on the accelerator performance. ATLAS is one of the main experiments at the LHC. In order to provide an accurate and reliable luminosity determination, ATLAS uses a variety of different sub-detectors and algorithms that measure the luminosity simultaneously. One of these sub-detectors are the Beam Condition Monitors (BCM) that were designed to protect the ATLAS detector from potentially dangerous beam losses. Due to its fast readout and very clean signals this diamond detector is providing in addition since May 2011 the official ATLAS luminosity. This thesis describes the calibration and performance of the BCM as a luminosity detec...

The development of the neutron flux measurement technology using SPNDs during nuclear fuel irradiation test

Energy Technology Data Exchange (ETDEWEB)

Kim, B. G.; Kang, Y. H.; Cho, M. S.; Joo, K. N.; Choi, M. H.; Park, S. J.; Shin, Y. T.; Oh, J. M.; Kim, Y. J

2004-03-01

As a part of the development of instrumentation technologies for a nuclear fuel irradiation test in HANARO(High-flux Advanced Nuclear Application Reactor), a study is performed to measure and evaluate the neutron flux at the same position as the nuclear fuel during irradiation test using the SPND(Self Powered Neutron Detector). To perform this study, rhodium type SPNDs and amplifier are selected suitable to irradiation test, and the selected SPNDs are installed in instrumented fuel capsule(02F-11K). The irradiation test using a instrumented fuel capsule are performed in the OR5 vertical hole of HANARO for about 54 days, and SPND output signals are acquired successfully during irradiation test. Acquired SPND signals are analyzed and evaluated as a reliable data by COSMOS Code. This will be utilized for the fuel related research together with fuel center temperature and reactor operation data.

Planned studies of charge collection in non-uniformly irradiated Si and GaAs detectors

International Nuclear Information System (INIS)

Rosenfeld, A.; Reinhard, M.; Carolan, M.; Kaplan, G.; Lerch, M.; Alexiev, D.

1995-01-01

The aim of this project is to study the time and amplitude characteristics of silicon ion-implanted detectors non-uniformly irradiated with fast neutrons in order to predict their radiation behaviour in the LHC and space. It is expected in such detectors increases of the charge deficit due to trapping by large scale traps and transient time increases due to the reduction of the mobility. The theoretical model will be modified to describe the charge kinetics in the electrical field of the detector created by a non uniform space charge distribution. Experimental confirmation techniques are needed to develop non uniform predictable damage of silicon detectors using fast neutron sources (accelerators, reactors) and to study peculiarities of the charge transport in different parts of the detector. In parallel to experimental research will be started the theoretical development of the charge transport model for non-uniform distribution of space charge in the depletion layer (Neff). The model will include the linear distribution of Neff(y) along the detector as well as the change of sign of Neff (conversion from n to p type of silicon) inside the detector

A shielded measurement system for irradiated nuclear fuel measurements

International Nuclear Information System (INIS)

Mosby, W.R.; Aumeier, S.E.; Klann, R.T.

1999-01-01

The US Department of Energy (DOE) is driving a transition toward dry storage of irradiated nuclear fuel (INF), toward characterization of INF for final disposition, and toward resumption of measurement-based material control and accountability (MC and A) efforts for INF. For these reasons, the ability to efficiently acquire radiological measurements of INF in a dry environment is important. The DOE has recently developed a guidance document proposing MC and A requirements for INF. The intent of this document is to encourage the direct measurement of INF on inventory within DOE. The guidance document reinforces and clarifies existing material safeguards requirements as they pertain to INF. Validation of nuclear material contents of non-self-protecting INF must be accomplished by direct measurement, application of validated burnup codes using qualified initial fissile content, burnup data, and age or by other valid means. The fuel units must remain intact with readable identification numbers. INF may be subject to periodic inventories with visual item accountability checks. Quantitative measurements may provide greater assurance of the integrity of INF inventories at a lower cost and with less personnel exposure than visual item accountability checks. Currently, several different approaches are used to measure the radiological attributes of INF. Although these systems are useful for a wide variety of applications, there is currently no relatively inexpensive measurement system that is readily deployable for INF measurements for materials located in dry storage. The authors present the conceptual design of a shielded measurement system (SMS) that could be used for this purpose. The SMS consists of a shielded enclosure designed to house a collection of measurement systems to allow measurements on spent fuel outside of a hot cell. The phase 1 SMS will contain 3 He detectors and ionization chambers to allow for gross neutron and gamma-ray measurements. The phase 2 SMS

New detectors of neutron, gamma- and X-radiations

CERN Document Server

Lobanov, N S

2002-01-01

Paper presents new detectors to record absorbed doses of neutron, gamma- and X-ray radiations within 0-1500 Mrad range. DBF dosimeter is based on dibutyl phthalate. EDS dosimeter is based on epoxy (epoxide) resin, while SD 5-40 detector is based on a mixture of dibutyl phthalate and epoxy resin. Paper describes experimental techniques to calibrate and interprets the measurement results of absorbed doses for all detectors. All three detectors cover 0-30000 Mrad measured does range. The accuracy of measurements is +- 10% independent (practically) of irradiation dose rates within 20-2000 rad/s limits under 20-80 deg C temperature

Irradiation of 4H-SiC UV detectors with heavy ions

International Nuclear Information System (INIS)

Kalinina, E. V.; Lebedev, A. A.; Bogdanova, E.; Berenquier, B.; Ottaviani, L.; Violina, G. N.; Skuratov, V. A.

2015-01-01

Ultraviolet (UV) photodetectors based on Schottky barriers to 4H-SiC are formed on lightly doped n-type epitaxial layers grown by the chemical vapor deposition method on commercial substrates. The diode structures are irradiated at 25°C by 167-MeV Xe ions with a mass of 131 amu at a fluence of 6 × 10 9 cm −2 . Comparative studies of the optical and electrical properties of as-grown and irradiated structures with Schottky barriers are carried out in the temperature range 23–180°C. The specific features of changes in the photosensitivity and electrical characteristics of the detector structures are accounted for by the capture of photogenerated carriers into traps formed due to fluctuations of the conduction-band bottom and valence-band top, with subsequent thermal dissociation

A neutron activation detector

International Nuclear Information System (INIS)

Ambardanishvili, T.S.; Kolomiitsev, M.A.; Zakharina, T.Y.; Dundua, V.J.; Chikhladze, N.V.

1973-01-01

The present invention concerns a neutron activation detector made from a moulded and hardened composition. According to the invention, that composition contains an activable substance constituted by at least two chemical elements and/or compounds of at least two chemical elements. Each of these chemical elements is capable of reacting with the neutrons forming radio-active isotopes with vatious levels of energy during desintegration. This neutron detector is mainly suitable for measuring integral thermal neutron and fast neutron fluxes during irradiation of the sample, and also for measuring the intensities of neutron fields [fr

Measurement of characteristic prompt gamma rays emitted from oxygen and carbon in tissue-equivalent samples during proton beam irradiation.

Science.gov (United States)

Polf, Jerimy C; Panthi, Rajesh; Mackin, Dennis S; McCleskey, Matt; Saastamoinen, Antti; Roeder, Brian T; Beddar, Sam

2013-09-07

The purpose of this work was to characterize how prompt gamma (PG) emission from tissue changes as a function of carbon and oxygen concentration, and to assess the feasibility of determining elemental concentration in tissues irradiated with proton beams. For this study, four tissue-equivalent water-sucrose samples with differing densities and concentrations of carbon, hydrogen, and oxygen were irradiated with a 48 MeV proton pencil beam. The PG spectrum emitted from each sample was measured using a high-purity germanium detector, and the absolute detection efficiency of the detector, average beam current, and delivered dose distribution were also measured. Changes to the total PG emission from (12)C (4.44 MeV) and (16)O (6.13 MeV) per incident proton and per Gray of absorbed dose were characterized as a function of carbon and oxygen concentration in the sample. The intensity of the 4.44 MeV PG emission per incident proton was found to be nearly constant for all samples regardless of their carbon concentration. However, we found that the 6.13 MeV PG emission increased linearly with the total amount (in grams) of oxygen irradiated in the sample. From the measured PG data, we determined that 1.64 × 10(7) oxygen PGs were emitted per gram of oxygen irradiated per Gray of absorbed dose delivered with a 48 MeV proton beam. These results indicate that the 6.13 MeV PG emission from (16)O is proportional to the concentration of oxygen in tissue irradiated with proton beams, showing that it is possible to determine the concentration of oxygen within tissues irradiated with proton beams by measuring (16)O PG emission.

Fast neutron detection by means of an organic solid state track detector

International Nuclear Information System (INIS)

Doerschel, B.; Streubel, G.

1980-01-01

Solid state track detectors consisting of cellulose triacetate foils are appropriate for measuring the fast neutron fluence without applying external radiators. Detector sensitivity has been determined as a function of neutron energy by performing irradiations with various neutron sources and monoenergetic neutrons of different energies. A comparison with theoretical results given in the literature for a simple model of track recording has shown sufficient agreement. The measuring errors and the influence of spectral changes in the neutron field on detector response are discussed for the studied method of fluence measurement. By means of these errors the measuring range has been determined for well defined irradiation conditions, taking into account spectral changes in the neutron field. (author)

Detection and measurement of neutron-irradiated gemstones

International Nuclear Information System (INIS)

Bunnak, S.; Jerachanchai, S.; Chinudomsub, K.; Saiyut, K.

1990-01-01

Color enhance gemstone, neutron-irradiated topaz, was analyzed by gamma spectrometry for examining characteristic and activity. Topaz was irradiated in the wet-tube facility of the Research Reactor TRR/1 which neutron fluence is 2.52x10 17 neutron per square centimeter. After 100 days of decay, topaz was sampling to the qualitative and quantitative analysis using multichannel analyzer of Nuclear Data Model ND65 and hyper pure germanium detector. Calculation and evaluation were done by microcomputer IBM/PC 640 KB RAM. The qualitative analysis showed that the neutron-irradiated topaz has 2 major isotopes, i.e., Ta-182 and Sc-46. Quantitative activity was compared with reference standard source Eu-152 (NBS) and the results were shown in the table 1. The Health Physics Division, OAEP, inspected on 6240.9 gm of the neutron-irradiated topaz using standard release limit 2 nCi/gm (74 Bq/gm). It was found that only 423.9 gm out of the total amount were over the standard release limit

Technology developments and first measurements of Low Gain Avalanche Detectors (LGAD) for high energy physics applications

International Nuclear Information System (INIS)

Pellegrini, G.; Fernández-Martínez, P.; Baselga, M.; Fleta, C.; Flores, D.; Greco, V; Hidalgo, S.; Mandić, I.; Kramberger, G.; Quirion, D.; Ullan, M.

2014-01-01

This paper introduces a new concept of silicon radiation detector with intrinsic multiplication of the charge, called Low Gain Avalanche Detector (LGAD). These new devices are based on the standard Avalanche Photo Diodes (APD) normally used for optical and X-ray detection applications. The main differences to standard APD detectors are the low gain requested to detect high energy charged particles, and the possibility to have fine segmentation pitches: this allows fabrication of microstrip or pixel devices which do not suffer from the limitations normally found [1] in avalanche detectors. In addition, a moderate multiplication value will allow the fabrication of thinner devices with the same output signal of standard thick substrates. The investigation of these detectors provides important indications on the ability of such modified electrode geometry to control and optimize the charge multiplication effect, in order to fully recover the collection efficiency of heavily irradiated silicon detectors, at reasonable bias voltage, compatible with the voltage feed limitation of the CERN High Luminosity Large Hadron Collider (HL-LHC) experiments [2]. For instance, the inner most pixel detector layers of the ATLAS tracker will be exposed to fluences up to 2×10 16 1 MeV n eq /cm 2 , while for the inner strip detector region fluences of 1×10 15 n eq /cm 2 are expected. The gain implemented in the non-irradiated devices must retain some effect also after irradiation, with a higher multiplication factor with respect to standard structures, in order to be used in harsh environments such those expected at collider experiments

Ion detectors for isotopic measurements

Energy Technology Data Exchange (ETDEWEB)

McCormick, A.

1978-12-15

Detector development over the past two decades has been such that this is now the least likely part of the mass spectrometry equipment to give rise to the sort of measurement errors to cause concern. It is now possible to choose from a number of different types of device which can provide more or less 100% efficiency in ion beam detection under all conceivable experimental conditions required for isotopic analysis, from measurement of large samples using the traditional Faraday cage to measurement of exceedingly small ion currents by ion counting techniques. There are even methods of distinguishing one type of ionic species from another in the detector, thus improving the accuracy when unwanted isobaric species might otherwise grossly distort the measurement. Notable contributions to detector development for nuclear measurements have been made by Dietz at the Knolls Atomic Power Laboratory, by Barnett at Oak Ridge and by Daly at Atomic Weapons Research Establishment (AWRE), Aldermaston. This paper describes the detection methods which are currently in use at AWRE for isotopic analysis of solid samples for routine applications as well as non-routine applications. Other methods are merely mentioned as a stimulus for discussion.

Detector calibration measurements in CRESST

Energy Technology Data Exchange (ETDEWEB)

Westphal, W. [Technische Universitaet Muenchen, Physik Department E15, James-Franck-Strasse, D-85748 Garching (Germany)]. E-mail: westphal@ph.tum.de; Coppi, C. [Technische Universitaet Muenchen, Physik Department E15, James-Franck-Strasse, D-85748 Garching (Germany); Feilitzsch, F. von [Technische Universitaet Muenchen, Physik Department E15, James-Franck-Strasse, D-85748 Garching (Germany); Isaila, C. [Technische Universitaet Muenchen, Physik Department E15, James-Franck-Strasse, D-85748 Garching (Germany); Jagemann, T. [Eberhard Karls Universitaet Tuebingen, Physikalisches Institut I, Auf der Morgenstelle 14, D-72076 Tuebingen (Germany); Jochum, J. [Eberhard Karls Universitaet Tuebingen, Physikalisches Institut I, Auf der Morgenstelle 14, D-72076 Tuebingen (Germany); Koenig, J. [Technische Universitaet Muenchen, Physik Department E15, James-Franck-Strasse, D-85748 Garching (Germany); Lachenmaier, T. [Technische Universitaet Muenchen, Physik Department E15, James-Franck-Strasse, D-85748 Garching (Germany); Lanfranchi, J.-C. [Technische Universitaet Muenchen, Physik Department E15, James-Franck-Strasse, D-85748 Garching (Germany); Potzel, W. [Technische Universitaet Muenchen, Physik Department E15, James-Franck-Strasse, D-85748 Garching (Germany); Rau, W. [Technische Universitaet Muenchen, Physik Department E15, James-Franck-Strasse, D-85748 Garching (Germany); Stark, M. [Technische Universitaet Muenchen, Physik Department E15, James-Franck-Strasse, D-85748 Garching (Germany); Wernicke, D. [Technische Universitaet Muenchen, Physik Department E15, James-Franck-Strasse, D-85748 Garching (Germany); VeriCold Technologies GmbH, Bahnhofstrasse 21, D-85737 Ismaning (Germany)

2006-04-15

The CRESST dark matter experiment uses the simultaneous measurement of the scintillation light and the heat signal of a CaWO{sub 4} crystal to discriminate between background electron recoil and nuclear recoil events. At the Technical University of Munich calibration measurements have been performed to characterize the detectors. These measurements include the determination of the light output and scintillation time constants of CaWO{sub 4} at temperatures below 50 mK. The setup used in these measurements consist of a CaWO{sub 4} crystal, which is mounted in a reflective housing together with a silicon light detector carrying an Ir/Au transition edge sensor (TES) evaporated directly onto it.

Trapping effect on the resolution of Ge(Li) detectors

International Nuclear Information System (INIS)

Venturini, L.; Suarez, A.A.

1980-01-01

This work describes the measurement of the resolution variation of a Ge(Li) detector as a function of irradiation position by a collimated gamma-ray beam. Also the resolution dependence has been measured as a function of the detector applied voltage, using collimated and non-collimated gamma-ray beam. (A.C.A.S.) [pt

Modelling infrared temperature measurements: implications for laser irradiation and cryogen cooling studies

International Nuclear Information System (INIS)

Choi, B.; Pearce, J.A.; Welch, A.J.

2000-01-01

The use of thermographic techniques has increased as infrared detector technology has evolved and improved. For laser-tissue interactions, thermal cameras have been used to monitor the thermal response of tissue to pulsed and continuous wave irradiation. It is important to note that the temperature indicated by the thermal camera may not be equal to the actual surface temperature. It is crucial to understand the limitations of using thermal cameras to measure temperature during laser irradiation of tissue. The goal of this study was to demonstrate the potential difference between measured and actual surface temperatures in a quantitative fashion using a 1D finite difference model. Three ablation models and one cryogen spray cooling simulation were adapted from the literature, and predictions of radiometric temperature measurements were calculated. In general, (a) steep superficial temperature gradients, with a surface peak, resulted in an underestimation of the actual surface temperature, (b) steep superficial temperature gradients, with a subsurface peak, resulted in an overestimation, and (c) small gradients led to a relatively accurate temperature estimate. (author)

Signal height in silicon pixel detectors irradiated with pions and protons

International Nuclear Information System (INIS)

Rohe, T.; Acosta, J.; Bean, A.; Dambach, S.; Erdmann, W.; Langenegger, U.; Martin, C.; Meier, B.; Radicci, V.; Sibille, J.; Trueb, P.

2010-01-01

Pixel detectors are used in the innermost part of multi-purpose experiments at the Large Hadron Collider (LHC) and are therefore exposed to the highest fluences of ionising radiation, which in this part of the detectors consists mainly of charged pions. The radiation hardness of the detectors has been tested thoroughly up to the fluences expected at the LHC. In case of an LHC upgrade the fluence will be much higher and it is not yet clear up to which radii the present pixel technology can be used. To establish such a limit, pixel sensors of the size of one CMS pixel readout chip (PSI46V2.1) have been bump bonded and irradiated with positive pions up to 6x10 14 n eq /cm 2 at PSI and with protons up to 5x10 15 n eq /cm 2 . The sensors were taken from production wafers of the CMS barrel pixel detector. They use n-type DOFZ material with a resistance of about 3.7kΩcm and an n-side read out. As the performance of silicon sensors is limited by trapping, the response to a Sr-90 source was investigated. The highly energetic beta-particles represent a good approximation to minimum ionising particles. The bias dependence of the signal for a wide range of fluences will be presented.

Measurement and analysis of high energy radiation through activation detectors. Application in dosimetry

International Nuclear Information System (INIS)

Sklavenitis, L.

1967-10-01

This work is concerned with the possibility of measurement and analysis of radiation fluences within objects of small volume submitted to a high energy proton beam. The first part, consecrated to the establishment of a method of analysis, comprises a detailed study of the radiation nature and energy spectra as well as of the various dosimetry methods. In order to select a group of detectors, high energy nuclear reactions were systematically studied and for some of them cross sections were measured or calculated: for example the cross section of the reaction 11 B (p,n) 11 C between 150 and 3000 MeV and of the reaction 34 S (p,2pn) 32 P between 50 and 3000 MeV. The second part is relative to the application of the fore-mentioned analysis to radiation within a tissue equivalent phantom irradiated by 3 GeV protons. This analysis is sufficiently detailed to allow the reconstitution of the absorbed doses, the dose equivalent and, contingent on a better knowledge of the dose due to heavy particles, the quality factors. It allowed also to follow the evolution of the various dosimetric data as a function of the depth inside the phantom and to verify calculations already done by other researchers. The comparison of the measured doses and the corresponding detector activities revealed the possibility that some detectors could give directly the absorbed dose, or even the dose equivalent, by a simple activity measurement. (author) [fr

Radiation hard detectors from silicon enriched with both oxygen and thermal donors improvements in donor removal and long-term stability with regard to neutron irradiation

CERN Document Server

Li, Z; Eremin, V; Dezillie, B; Chen, W; Bruzzi, M

2002-01-01

Detectors made on the silicon wafers with high concentration of thermal donors (TD), which were introduced during the high temperature long time (HTLT) oxygenation procedure, have been investigated in the study of radiation hardness with regard to neutron irradiation and donor removal problems in irradiated high resistivity Si detectors. Two facts have been established as the evidence of radiation hardness improvement of HTLT(TD) Si detectors irradiated below approx 10 sup 1 sup 4 n/cm sup 2 compared to detectors made on standard silicon wafers: the increase of space charge sign inversion fluence (of 1 MeV neutrons) due to lower initial Si resistivity dominated by TD, and the gain in the reverse annealing time constant tau favourable for this material. Coupled with extremely high radiation tolerance to protons observed earlier ('beta zero' behaviour in a wide range of fluence), detectors from HTLT(TD) Si may be unique for application in the experiments with multiple radiations. The changes in the effective sp...

EPR measurements in irradiated polyacetylene

International Nuclear Information System (INIS)

Hola, O.; Foeldesova, M.

1990-01-01

The influence of γ-irradiation on the paramagnetic properties of polyacetylene, and the dependence of the EPR spectra on the radiation dose in samples of irradiated polyacetylene were studied. The measurements show that no essential changes of the spin mobility occurred during irradiation. (author) 3 refs.; 2 figs

Gamma radiation detectors for safeguards applications

International Nuclear Information System (INIS)

Carchon, R.; Moeslinger, M.; Bourva, L.; Bass, C.; Zendel, M.

2007-01-01

The IAEA uses extensively a variety of gamma radiation detectors to verify nuclear material. These detectors are part of standardized spectrometry systems: germanium detectors for High-Resolution Gamma Spectrometry (HRGS); Cadmium Zinc Telluride (CZT) detectors for Room Temperature Gamma Spectrometry (RTGS); and NaI(Tl) detectors for Low Resolution Gamma Spectrometry (LRGS). HRGS with high-purity Germanium (HpGe) detectors cooled by liquid nitrogen is widely used in nuclear safeguards to verify the isotopic composition of plutonium or uranium in non-irradiated material. Alternative cooling systems have been evaluated and electrically cooled HpGe detectors show a potential added value, especially for unattended measurements. The spectrometric performance of CZT detectors, their robustness and simplicity are key to the successful verification of irradiated materials. Further development, such as limiting the charge trapping effects in CZT to provide improved sensitivity and energy resolution are discussed. NaI(Tl) detectors have many applications-specifically in hand-held radioisotope identification devices (RID) which are used to detect the presence of radioactive material where a lower resolution is sufficient, as they benefit from a generally higher sensitivity. The Agency is also continuously involved in the review and evaluation of new and emerging technologies in the field of radiation detection such as: Peltier-cooled CdTe detectors; semiconductor detectors operating at room temperature such as HgI 2 and GaAs; and, scintillator detectors using glass fibres or LaBr 3 . A final conclusion, proposing recommendations for future action, is made

A study on the measurement and evaluation of neutron flux using SPNDs during nuclear fuel irradiation test

Energy Technology Data Exchange (ETDEWEB)

Son, J. M.; Kim, B. K.; Oh, J. M.; Park, S. J.; Lee, B. H.; Seo, C. G.; Kang, Y. H. [KAERI, Taejon (Korea, Republic of)

2003-10-01

As a part of the development of instrumentation technologies for a nuclear fuel irradiation test in HANARO(High-Flux Advanced Nuclear Application Reactor), a study is performed to measure and evaluate the neutron flux at the same position as the nuclear fuel during irradiation test using the SPND(Self Powered Neutron Detector). To perform this study, rhodium type SPNDs and amplifier are selected suitable to irradiation test, and the selected SPNDs are installed in instrumented fuel capsule(02F-11K). The irradiation test using a instrumented fuel capsule are performed in the OR5 vertical hole of HANARO for about 54 days, and SPND output signals are acquired successfully during irradiation test. Acquired SPND signals are analyzed and evaluated as a reliable data by COSMOS Code, and this will be utilized for the fuel related research together with fuel center temperature and reactor operation data.

Broadband radiometric LED measurements

Science.gov (United States)

Eppeldauer, G. P.; Cooksey, C. C.; Yoon, H. W.; Hanssen, L. M.; Podobedov, V. B.; Vest, R. E.; Arp, U.; Miller, C. C.

2016-09-01

At present, broadband radiometric LED measurements with uniform and low-uncertainty results are not available. Currently, either complicated and expensive spectral radiometric measurements or broadband photometric LED measurements are used. The broadband photometric measurements are based on the CIE standardized V(λ) function, which cannot be used in the UV range and leads to large errors when blue or red LEDs are measured in its wings, where the realization is always poor. Reference irradiance meters with spectrally constant response and high-intensity LED irradiance sources were developed here to implement the previously suggested broadband radiometric LED measurement procedure [1, 2]. Using a detector with spectrally constant response, the broadband radiometric quantities of any LEDs or LED groups can be simply measured with low uncertainty without using any source standard. The spectral flatness of filtered-Si detectors and low-noise pyroelectric radiometers are compared. Examples are given for integrated irradiance measurement of UV and blue LED sources using the here introduced reference (standard) pyroelectric irradiance meters. For validation, the broadband measured integrated irradiance of several LED-365 sources were compared with the spectrally determined integrated irradiance derived from an FEL spectral irradiance lamp-standard. Integrated responsivity transfer from the reference irradiance meter to transfer standard and field UV irradiance meters is discussed.

Passive detectors for neutron fluence measurement

International Nuclear Information System (INIS)

Holt, P.D.

1985-01-01

The use of neutron activation detectors (slow neutron detectors and threshold detectors) and fission track detectors for radiological protection purposes, principally in criticality dosimetry, dosimetry of pulsed accelerators and calibration of neutron fluxes is discussed. References are given to compilations of cross sections. For the determination of the activity induced, either beta ray or gamma ray counting may be used. For beta-ray counting, thin foils are usually necessary which result in low neutron sensitivity. When fission track detectors are used, it is necessary to know the efficiency of track registration. Alternatively, a detector-counter system may be calibrated by exposure to a known flux of monoenergetic neutrons. Usually, the sensitivity of activation detectors is low because small foils are used. For criticality dosimetry, calibration work and shielding studies on accelerators, low sensitivity is acceptable. However, there are some instances where, by the use of long integration times, or very large quantities of detector material with gamma ray detection, neutron fluences in operational areas have been measured. (author)

Technology development of p-type microstrip detectors with radiation hard p-spray isolation

International Nuclear Information System (INIS)

Pellegrini, G.; Fleta, C.; Campabadal, F.; Diez, S.; Lozano, M.; Rafi, J.M.; Ullan, M.

2006-01-01

A technology for the fabrication of p-type microstrip silicon radiation detectors using p-spray implant isolation has been developed at CNM-IMB. The p-spray isolation has been optimized in order to withstand a gamma irradiation dose up to 50 Mrad (Si), which represents the ionization radiation dose expected in the middle region of the SCT-Atlas detector of the future Super-LHC during 10 years of operation. The best technological options for the p-spray implant were found by using a simulation software package and dedicated calibration runs. Using the optimized technology, detectors have been fabricated in the Clean Room facility of CNM-IMB, and characterized by reverse current and capacitance measurements before and after irradiation. The average full depletion voltage measured on the non-irradiated detectors was V FD =41±3 V, while the leakage current density for the microstrip devices at V FD +20 V was 400 nA/cm 2

CR-39 as induced track detector in reactor: irradiation effect

International Nuclear Information System (INIS)

Zylberberg, H.

1989-07-01

A systematic study about reactor's neutrons radiation effect and gamma radiation effect on the properties of CR-39 that are significant for its use as induced fission track detector is showed. The following studies deserved attention: kinetics of the fission track chemical development; efficiency to register and to develop fission track; losses of developable tracks; variation in the number of developable tracks and variation in the visible and ultraviolet radiation spectrum. The dissertation is organized in seven specific chapters: solid state nuclear tracks (SSNT); CR-39 as SSNT; objectives and problems presentation; preparation and characterization of CR-39 as SSNT; gamma irradiation effect on the properties of CR-39 as SSNT; reactor neutron irradiation effect on the properties of CR-39 as SSNT and, results discussions and conclusions. The main work contributions are the use of CR-39 in the determination of fissionable nuclide as thorium and uranium in solid and liquid samples; gamma radiation damage on CR-39 as well as the reactor's neutron damage on CR-39. (B.C.A.) 62 refs, 53 figs, 21 tabs

Effects of DD and DT neutron irradiation on some Si devices for fusion diagnostics

International Nuclear Information System (INIS)

Tanimura, Y.; Iida, T.

1998-01-01

In order to examine the difference in the irradiation effects on Si devices between DT and DD neutrons, CCD image sensors, memory ICs and a Si detector were irradiated with neutrons from a deuteron accelerator. The transient effects (i.e. neutron-induced background noises) and permanent effects (i.e. neutron damage) on them were in situ measured during irradiation. Regarding the transient effects, brightening spot noises, soft-error upsets and induced-charge noises were measured for the CCDs, memory ICs and Si detector, respectively. As for the permanent effect, the number of damaged cells of the CCDs and the leakage current of the Si detector increased with neutron fluence. Also we developed a Monte-Carlo code with the TRIM code to evaluate the correlation of DT and DD neutron effects on Si devices. The calculated correlation factor of DT and DD neutron damage for Si devices agreed approximately with the correlation factor obtained from the irradiation experiments on the CCDs and Si detector. (orig.)

Effects of DD and DT neutron irradiation on some Si devices for fusion diagnostics

Science.gov (United States)

Tanimura, Yoshihiko; Iida, Toshiyuki

1998-10-01

In order to examine the difference in the irradiation effects on Si devices between DT and DD neutrons, CCD image sensors, memory ICs and a Si detector were irradiated with neutrons from a deuteron accelerator. The transient effects (i.e. neutron-induced background noises) and permanent effects (i.e. neutron damage) on them were in situ measured during irradiation. Regarding the transient effects, brightening spot noises, soft-error upsets and induced-charge noises were measured for the CCDs, memory ICs and Si detector, respectively. As for the permanent effect, the number of damaged cells of the CCDs and the leakage current of the Si detector increased with neutron fluence. Also we developed a Monte-Carlo code with the TRIM code to evaluate the correlation of DT and DD neutron effects on Si devices. The calculated correlation factor of DT and DD neutron damage for Si devices agreed approximately with the correlation factor obtained from the irradiation experiments on the CCDs and Si detector.

Reference detectors for low flux optical radiation measurements

International Nuclear Information System (INIS)

Bellouati-Ghazi, Amal

2003-01-01

The parametric down conversion of photons generated in a non-linear crystal gives rise to two correlated photons. Associated to a System of counting of coincidences, this phenomenon makes possible the quantum efficiency measurements of detectors working on photon counting levels, without using neither sources nor detectors of references. This new method was developed at BNMINM with the aim to realize new standards detectors in the field of weak flows. It allows the determination of quantum efficiency with a relative uncertainty of 1,1%. A comparison with the IENGF (Italy) bearing on the quantum determination of efficiency of one of BNM-FNM detectors made possible to confront the exactitude of the measuring equipment. This detector was also made the object of a comparison with the French reference of radiometry, the cryogenic radiometer, the results were in agreement with uncertainties of measurements. (author) [fr

Measurement of the Current Related Damage Rate at {-}50(°) C and Consequences on Macropixel Detector Operation in Space Experiments

Science.gov (United States)

Segneri, Gabriele; Brown, Craig; Carpenter, James-D.; Kuhnle, Bernd; Lauf, Thomas; Lechner, Peter; Lutz, Gerhard; Rummel, Stefan; Struder, Lothar; Treis, Johannes; Whitford, Chris

2009-12-01

A diode irradiation with 10-MeV protons was performed to measure the silicon current related damage rate at a temperature of -50°C. This measurement was fundamental to predict the performance of the detectors which will be used in the X-ray spectrometers of the Simbol-X and BepiColombo space missions. These detectors consist of arrays of large area silicon drift chambers with integrated depleted p-channel field effect transistors. The leakage current increase due to radiation damage and its consequent energy resolution degradation can be critical for these missions, specially for BepiColombo. These effects cannot be predicted because, during the whole missions, the sensors will be kept at temperatures below -40°C, and the existing models are based on measurements on structures which underwent annealing at higher temperatures. An irradiation experiment was performed to measure the current related damage rate at - 50°C, and the obtained value was (11.1 ± 0.2) X 10-17 A/cm. This result implies that it will be possible to achieve the Simbol-X energy resolution, whereas some annealing strategies will be needed for the BepiColombo mission. The annealing behaviour at 60°C was studied as well and the results are in agreement with the already available measurements.

Effect of trapping of charge carriers on the resolution of Ge(Li) detectors; Influencia da captura de portadores de cargas sobre a resolucao em detectores Ge(Li)

Energy Technology Data Exchange (ETDEWEB)

Venturini, Luzia

1979-07-01

In this work a measurement is described of the variation of the resolution of a Ge(Li) detector as a function of the position of irradiation of a collimated gamma-ray beam. Also the variation of the resolution has been measured as a function of the applied detector voltage, using a collimated and a non-collimated gamma-ray beam. The measurement indicate that in the process of charge collection loss of holes predominates and the best resolution is obtained in the middle of the compensated region. It has been verified that, in the case of a collimated gamma beam the detector resolution improves with increasing detector bias up to at least 5100 Volts. For a non-collimated gamma beam, however, the resolution reaches a constant value at about 4400 Volts. The dependence of resolution on the position of irradiation can be accounted for by introducing a local ionization factor different from the usual position independent Fano factor. (author)

Inner detector alignment and top-quark mass measurement with the ATLAS detector

CERN Document Server

Moles-Valls, Regina

This thesis is divided in two parts: one related with the alignment of the ATLAS Inner Detector tracking system and other with the measurement of the top-quark mass. Both topics are connected by the Globalχ2 fitting method. In order to measure the properties of the particles with high accuracy, the ID detector is composed by devices with high intrinsic resolution. If by any chance the position of the modules in the detector is known with worse precision than their intrinsic resolution this may introduce a distortion in the reconstructed trajectory of the particles or at least degrade the tracking resolution. The alignment is the responsible of determining the location of each module with high precision and avoiding therefore any bias in the physics results. During the commissioning of the detector, different alignment exercises were performed for preparing the Globalχ2 algorithm (the CSC , the FDR, weak modes studies,…). At the same time, the ATLAS detector was collecting million of cosmic rays which were...

Detector characterization for efficiency calibration in different measurement geometries

International Nuclear Information System (INIS)

Toma, M.; Dinescu, L.; Sima, O.

2005-01-01

In order to perform an accurate efficiency calibration for different measurement geometries a good knowledge of the detector characteristics is required. The Monte Carlo simulation program GESPECOR is applied. The detector characterization required for Monte Carlo simulation is achieved using the efficiency values obtained from measuring a point source. The point source was measured in two significant geometries: the source placed in a vertical plane containing the vertical symmetry axis of the detector and in a horizontal plane containing the centre of the active volume of the detector. The measurements were made using gamma spectrometry technique. (authors)

Detector to detector corrections: a comprehensive experimental study of detector specific correction factors for beam output measurements for small radiotherapy beams

DEFF Research Database (Denmark)

Azangwe, Godfrey; Grochowska, Paulina; Georg, Dietmar

2014-01-01

-doped aluminium oxide (Al2O3:C), organic plastic scintillators, diamond detectors, liquid filled ion chamber, and a range of small volume air filled ionization chambers (volumes ranging from 0.002 cm3 to 0.3 cm3). All detector measurements were corrected for volume averaging effect and compared with dose ratios...... measurements, the authors recommend the use of detectors that require relatively little correction, such as unshielded diodes, diamond detectors or microchambers, and solid state detectors such as alanine, TLD, Al2O3:C, or scintillators....

Measurements of possible type inversion in silicon junction detectors by fast neutron irradiation

International Nuclear Information System (INIS)

Li, Z.; Kraner, H.W.

1991-05-01

The successful application of silicon position sensitive detectors in experiments at the SSC or LHC depends on an accurate assessment of the radiation tolerance of this detector species. In particular, fast neutrons (E av = 1 MeV) produce bulk displacement damage that is projected, from estimated fluences, to cause increased generation (leakage) current, charge collection deficiencies, resistivity changes and possibly semiconductor type change or inversion. Whereas the leakage current increase was believed to be the major concern for estimated fluences of 10 12 n/cm 2 experiment year at the initial SSC luminosity of 10 33 /cm 2 -sec, increased luminosity and exposure time has raised the possible exposure to 10 14 n/cm 2 , which opens the door for the several other radiation effects suggested above to play observable and significant roles in detector degradation or change. 17 refs., 19 figs

Irradiation induced effects in the FE-I4 front-end chip of the ATLAS IBL detector

CERN Document Server

La Rosa, Alessandro; The ATLAS collaboration

2016-01-01

The ATLAS Insertable B-Layer (IBL) detector was installed into the ATLAS experiment in 2014 and has been in operation since 2015. During the first year of IBL data taking an increase of the low voltage currents produced by the FE-I4 front-end chip was observed and this increase was traced back to the radiation damage in the chip. The dependence of the current on the total-ionising dose and temperature has been tested with Xray and proton irradiations and will be presented in this paper together with the detector operation guidelines.

Detector Control System for CMS RPC at GIF++

CERN Document Server

Gul, Muhammad

2016-01-01

In the framework of the High Luminosity LHC upgrade program, the CMS muon groupbuilt several different RPC prototypes that are now under test at the new CERN Gamma Irradiation Facility (GIF++). A dedicated Detector Control System has been developed using the WinCC-OA tool to control and monitor these prototype detectors and to store the measured parameters data.

Characterisation of Silicon Timing Detectors for the RD50 Collaboration

CERN Document Server

Immig, David Maximilian

2017-01-01

Increasing pile-up and irradiation following with the high luminosity upgrade of the LHC, demands the development of improved semiconductor detectors. The former problem can be reduced by more precise time information, which can be obtained using a future detector based on the low gain avalanche diode (LGAD). LGADs are studied by the RD50-Collaboration, which studies the characteristics of semiconductor devices to improve these for future requirements of high energy physics. This reports is engaged with the process to characterise semiconductor detectors, specially LGADs, with capacitance-voltage and current-voltage measurements as well as transient current techniques of un- and irradiated semiconductor devices.

Pre- and post-irradiation performance of FBK 3D silicon pixel detectors for CMS

International Nuclear Information System (INIS)

Krzywda, A.; Alagoz, E.; Bubna, M.; Obertino, M.; Solano, A.; Arndt, K.; Uplegger, L.; Betta, G.F. Dalla; Boscardin, M.; Ngadiuba, J.; Rivera, R.; Menasce, D.; Moroni, L.; Terzo, S.; Bortoletto, D.; Prosser, A.; Adreson, J.; Kwan, S.; Osipenkov, I.; Bolla, G.

2014-01-01

In preparation for the tenfold luminosity upgrade of the Large Hadron Collider (the HL-LHC) around 2020, three-dimensional (3D) silicon pixel sensors are being developed as a radiation-hard candidate to replace the planar ones currently being used in the CMS pixel detector. This study examines an early batch of FBK sensors (named ATLAS08) of three 3D pixel geometries: 1E, 2E, and 4E, which respectively contain one, two, and four readout electrodes for each pixel, passing completely through the bulk. We present electrical characteristics and beam test performance results for each detector before and after irradiation. The maximum fluence applied is 3.5×10 15 n eq /cm 2

Radiation effects in IRAS extrinsic infrared detectors

Science.gov (United States)

Varnell, L.; Langford, D. E.

1982-01-01

During the calibration and testing of the Infrared Astronomy Satellite (IRAS) focal plane, it was observed that the extrinsic photoconductor detectors were affected by gamma radiation at dose levels of the order of one rad. Since the flight environment will subject the focal plane to dose levels of this order from protons in single pass through the South Atlantic Anomaly, an extensive program of radiation tests was carried out to measure the radiation effects and to devise a method to counteract these effects. The effects observed after irradiation are increased responsivity, noise, and rate of spiking of the detectors after gamma-ray doses of less than 0.1 rad. The detectors can be returned almost to pre-irradiation performance by increasing the detector bias to breakdown and allowing a large current to flow for several minutes. No adverse effects on the detectors have been observed from this bias boost, and this technique will be used for IRAS with frequent calibration to ensure the accuracy of observations made with the instrument.

Measurements for the energy calibration of the TANSY neutron detectors

International Nuclear Information System (INIS)

Drozdowicz, K.; Hoek, M.; Aronsson, D.

1990-05-01

The report describes measurements performed for the energy calibration of the TANSY neutron detectors (two arrays of 16 detectors each one). The calibration procedure determines four calibration parameters for each detector. Results of the calibration measurements are given and test measurements are presented. A relation of the neutron detector calibration parameters to producer's data for the photomulipliers is analysed. Also the tests necessary during normal operation of the TANSY neutron spectrometer are elaborated (passive and active tests). A method how to quickly get the calibration parameters for a spare detector in an array of the neutron detectors is included

Performance of p-type micro-strip detectors after irradiation to $7.5x10^{15} p/cm^{2}$

CERN Document Server

Allport, Philip P; Lozano-Fantoba, Manuel; Sutcliffe, Peter; Velthuis, J J; Vossebeld, Joost Herman

2004-01-01

Exploiting the advantages of reading out segmented silicon from the n-side, we have produced test detectors with LHC pitch but 1 cm long strips which even after proton irradiation at the CERN PS to 7.5*10 /sup 15/ cm/sup -2/ show signal to noise greater than 8:1 using LHC speed electronics. This dose exceeds by a factor of 2 that required for a replacement of the ATLAS semiconductor tracker to cope with an upgrade of the LHC to a Super-LHC with 10 times greater luminosity. These detectors were processed on p-type starting material of resistivity ~ 2 k Omega cm and, unlike n-in-n designs, only required single-sided processing. Such technology should therefore provide a relatively inexpensive route to replacing the central tracking at both ATLAS and CMS for Super-LHC. The shorter strip length is required to limit the noise. Even at these extreme doses 30% of the non-irradiated signal is seen. This 7000e/sup -/ signal (in 280 mu m thick sensors) is very competitive with the post irradiation performance of other,...

Ultrafast photoconductor detector-laser-diode transmitter

International Nuclear Information System (INIS)

Wang, C.L.; Davis, B.A.; Davies, T.J.; Nelson, M.A.; Thomas, M.C.; Zagarino, P.A.

1987-01-01

We report the results of an experiment in which we used an ultrafast, photoconductive, radiation detector to drive a fast laser-diode transmitter. When we irradiated the neutron-damaged Cr-doped GaAs detector with 17-MeV electron beams, the temporal response was measured to be less than 30 ps. The pulses from this detector modulated a fast GaAlAs laser diode to transmit the laser output through 30- and 1100-m optical fibers. Preliminary results indicate that 50- and 80-ps time resolutions, respectively, are obtainable with these fibers. We are now working to integrate the photoconductive detector and the laser diode transmitter into a single chip

Radiation studies on resistive bulk-micromegas chambers at the CERN Gamma Irradiation Facility

CERN Document Server

Alvarez Gonzalez, Barbara; Camerlingo, Maria Teresa; Farina, Edoardo; Iengo, Paolo; Longo, Luigi; Samarati, Jerome; Sidiropoulou, Ourania; Wotschack, Joerg

2018-01-01

With the growing diffusion of resistive Micromegas detectors in HEP experiments the study of long-term aging behaviour is becoming more and more relevant. Two resistive bulk-Micromegas detectors were installed in May 2015 at the CERN Gamma Irradiation Facility and exposed to an intense gamma irradiation with the aim to study the detector behavior under high irradiation and the long-term aging. The detectors have an active area of 10 × 10 cm 2 , readout strip pitch of 400 μ m , amplification gap of 128 μ m and drift gap of 5 mm. The desired accumulated charge of more than 0.2 C/cm 2 has been reached for both chambers, equivalent to 10 years of HL-LHC operation. The efficiency, amplification, and resolution of the Micromegas after this long-term irradiation period is compared with the performance of a non irradiated detector. In addition, the latest results of the measured particle rate as a function of the amplification voltage is presented and compared with those obtained in 2015.

Interaction mean free path measurements for relativistic heavy ion fragments using CR39 plastic track detectors

International Nuclear Information System (INIS)

Drechsel, H.; Brechtmann, C.; Dreute, J.; Sonntag, S.; Trakowski, W.; Beer, J.; Heinrich, W.

1984-01-01

This paper describes an experiment measuring the interaction mean free paths for charge changing nuclear collisions of relativistic heavy ion fragments. We use a stack of CR39 plastic nuclear track detectors that was irradiated with 1.8 GeV/nucleon 40 Ar ions at the Berkeley Bevalac. About 1.5 x 10 7 etch cones were measured in this experiment using an automatic measuring system. By tracing the etch cones over successive plastic foils the particle trajectories in the stack were reconstructed. For 14185 trajectories with 6444 nuclear collisions of fragments with charge 9-15 the interaction mean free path in the plastic was determined. (orig.)

Qβ measurements with a total absorption detector

International Nuclear Information System (INIS)

Shibata, Michihiro; Kawade, Kiyoshi; Shindou, Terumasa; Kojima, Yasuaki; Taniguchi, Akihiro; Kawase, Yoichi; Ichikawa, Shin-ichi

2003-01-01

For Q β determination, we have developed a newly total absorption detector that can detect almost all radiation from the radioactive nuclei. The detector is composed of large volume and low background twin BGO scintillation detectors. The estimated efficiency is more than two orders of magnitude larger than those of Ge or Si detectors. The Q β s of some fission products of 235 U were successfully measured using an on-line mass separator for the first time (KUR-ISOL). We have proposed the possibility of determination Q β up to about 10 MeV using the detector without the knowledge of the decay scheme. (author)

Plastic scintillator detector for pulsed flux measurements

Science.gov (United States)

Kadilin, V. V.; Kaplun, A. A.; Taraskin, A. A.

2017-01-01

A neutron detector, providing charged particle detection capability, has been designed. The main purpose of the detector is to measure pulsed fluxes of both charged particles and neutrons during scientific experiments. The detector consists of commonly used neutron-sensitive ZnS(Ag) / 6LiF scintillator screens wrapping a layer of polystyrene based scintillator (BC-454, EJ-254 or equivalent boron loaded plastic). This type of detector design is able to log a spatial distribution of events and may be scaled to any size. Different variations of the design were considered and modelled in specialized toolkits. The article presents a review of the detector design features as well as simulation results.

Spectral Light Measurements in Microbenthic Phototrophic Communities with a Fiberoptic Microprobe Coupled to a Sensitive Diode-Array Detector Rid A-1977-2009

DEFF Research Database (Denmark)

KUHL, M.; JØRGENSEN, BB

1992-01-01

with microelectrode measurements of oxygenic photosynthesis in the coastal sediment. With an incident light intensity of 200 muEinst m-2 s-1, photon scalar irradiance reached a maximum of 283 muEinst m-2 s-1 at the sediment surface. The lower boundary of the euphotic zone was 2.2 mm below the surface at a light......A diode array detector system for microscale light measurements with fiber-optic microprobes was developed; it measures intensities of 400-900-nm light over >6 orders of magnitude with a spectral resolution of 2-5 nm. Fiber-optic microprobes to measure field radiance or scalar irradiance were...... extinction maxima in measured radiance spectra at 430-550 nm (Chl a and carotenoids), 620-625 nm (phycocyanin), 675 nm (Chl a), 745-750 nm (BChl c), 800-810 nm, and 860-880 nm (BChl a). Scalar irradiance spectra exhibited a different spectral composition and a higher light intensity at the sediment surface...

Standardization of UV LED measurements

Science.gov (United States)

Eppeldauer, G. P.; Larason, T. C.; Yoon, H. W.

2015-09-01

Traditionally used source spectral-distribution or detector spectral-response based standards cannot be applied for accurate UV LED measurements. Since the CIE standardized rectangular-shape spectral response function for UV measurements cannot be realized with small spectral mismatch when using filtered detectors, the UV measurement errors can be several times ten percent or larger. The UV LEDs produce broadband radiation and both their peaks or spectral bandwidths can change significantly. The detectors used for the measurement of these LEDs also have different spectral bandwidths. In the discussed example, where LEDs with 365 nm peak are applied for fluorescent crack-recognition using liquid penetrant (non-destructive) inspection, the broadband radiometric LED (signal) measurement procedure is standardized. A UV LED irradiance-source was calibrated against an FEL lamp standard to determine its spectral irradiance. The spectral irradiance responsivity of a reference UV meter was also calibrated. The output signal of the reference UV meter was calculated from the spectral irradiance of the UV source and the spectral irradiance responsivity of the reference UV meter. From the output signal, both the integrated irradiance (in the reference plane of the reference meter) and the integrated responsivity of the reference meter were determined. Test UV meters calibrated for integrated responsivity against the reference UV meter, can be used to determine the integrated irradiance from a field UV source. The obtained 5 % (k=2) measurement uncertainty can be decreased when meters with spectral response close to a constant value are selected.

A high-speed data acquisition system to measure low-level current from self-powered flux detectors in CANDU nuclear reactors

International Nuclear Information System (INIS)

Lawrence, C.B.; Hall, D.S.

1982-05-01

Self-powered flux detectors are used in CANDU nuclear power reactors to determine the spatial neutron flux distribution in the reactor core for use by both the reactor control and safety systems. To establish the dynamic response of different types of flux detectors, the Chalk River Nuclear Laboratories have an ongoing experimental irradiation program in the NRU research reactor for which a data acquistion system has been developed. The system described in this paper is used to measure the currents from the detectors both at a slow, regular logging interval, and at a rapid, adaptive rate following a reactor shutdown. Currents that range from 100 pA to 1 mA full scale can be measured from up to 38 detectors and stored at sampling rates of up to 20 samples per second. The dynamic characteristics of the detectors can be computed from the stored records. The data acquisition system comprises a DEC LSI-11/23 microcomputer, dual cartridge disks, floppy disks, a hard copy and a video display terminal. The RT-11 operating system is used and all application programs are written in FORTRAN

Development of Optical Fiber Detector for Measurement of Fast Neutron

International Nuclear Information System (INIS)

YAGI, Takahiro; KAWAGUCHI, Shinichi; MISAWA, Tsuyoshi; PYEON, Cheol Ho; UNESAKI, Hironobu; SHIROYA, Seiji; OKAJIMA, Shigeaki; TANI, Kazuhiro

2008-01-01

Measurement of fast neutron flux is important for investigation of characteristic of fast reactors. In order to insert a neutron detector in a narrow space such as a gap of between fuel plates and measure the fast neutrons in real time, a neutron detector with an optical fiber has been developed. This detector consists of an optical fiber whose tip is covered with mixture of neutron converter material and scintillator such as ZnS(Ag). The detector for fast neutrons uses ThO 2 as converter material because 232 Th makes fission reaction with fast neutrons. The place where 232 Th can be used is limited by regulations because 232 Th is nuclear fuel material. The purpose of this research is to develop a new optical fiber detector to measure fast neutrons without 232 Th and to investigate the characteristic of the detector. These detectors were used to measure a D-T neutron generator and fast neutron flux distribution at Fast Critical Assembly. The results showed that the fast neutron flux distribution of the new optical fiber detector with ZnS(Ag) was the same as it of the activation method, and the detector are effective for measurement of fast neutrons. (authors)

The effects of intense gamma-irradiation on the alpha-particle response of silicon carbide semiconductor radiation detectors

International Nuclear Information System (INIS)

Ruddy, Frank H.; Seidel, John G.

2007-01-01

Silicon Carbide (SiC) semiconductor radiation detectors are being developed for alpha-particle, X-ray and Gamma-ray, and fast-neutron energy spectrometry. SiC detectors have been operated at temperatures up to 306 deg. C and have also been found to be highly resistant to the radiation effects of fast-neutron and charged-particle bombardments. In the present work, the alpha-particle response of a SiC detector based on a Schottky diode design has been carefully monitored as a function of 137 Cs gamma-ray exposure. The changes in response have been found to be negligible for gamma exposures up to and including 5.4 MGy, and irradiations to higher doses are in progress

High-rate irradiation of 15 mm muon drift tubes and development of an ATLAS compatible readout driver for micromegas detectors

Energy Technology Data Exchange (ETDEWEB)

Zibell, Andre

2014-06-06

The upcoming luminosity upgrades of the LHC accelerator at CERN demand several upgrades to the detectors of the ATLAS muon spectrometer, mainly due to the proportionally increasing rate of uncorrelated background irradiation. This concerns also the ''Small Wheel'' tracking stations of the ATLAS muon spectrometer, where precise muon track reconstruction will no longer be assured when around 2020 the LHC luminosity is expected to reach values 2 to 5 times the design luminosity of 1 x 10{sup 34} cm{sup -2}s{sup -1}, and when background hit rates will exceed 10 kHz/cm{sup 2}. This, together with the need of an additional triggering station in this area with an angular resolution of 1 mrad, requires the construction of ''New Small Wheel'' detectors for a complete replacement during the long maintenance period in 2018 and 2019. As possible technology for these New Small Wheels, high-rate capable sMDT drift tubes have been investigated, based on the ATLAS 30 mm Monitored Drift Tube technology, but with a smaller diameter of 15 mm. In this work, a prototype sMDT chamber has been tested under the influence of high-rate irradiation with protons, neutrons and photons at the Munich tandem accelerator, simulating the conditions within a high luminosity LHC experiment. Tracking resolution and detection efficiency for minimum ionizing muons are presented as a function of irradiation rate. The experimental muon trigger geometry allows to distinguish between efficiency degradation due to deadtime effects and space charge in the detectors. Using modified readout electronics the analog pulse shape of the detector has been investigated for gain reduction and potential irregularities due to the high irradiation rates and ionization doses. This study shows that the sMDT detectors would fulfill all requirements for successful use in the ATLAS New Small Wheel endcap detector array, with an average spatial resolution of 140 μm and a track

High-rate irradiation of 15 mm muon drift tubes and development of an ATLAS compatible readout driver for micromegas detectors

International Nuclear Information System (INIS)

Zibell, Andre

2014-01-01

The upcoming luminosity upgrades of the LHC accelerator at CERN demand several upgrades to the detectors of the ATLAS muon spectrometer, mainly due to the proportionally increasing rate of uncorrelated background irradiation. This concerns also the ''Small Wheel'' tracking stations of the ATLAS muon spectrometer, where precise muon track reconstruction will no longer be assured when around 2020 the LHC luminosity is expected to reach values 2 to 5 times the design luminosity of 1 x 10 34 cm -2 s -1 , and when background hit rates will exceed 10 kHz/cm 2 . This, together with the need of an additional triggering station in this area with an angular resolution of 1 mrad, requires the construction of ''New Small Wheel'' detectors for a complete replacement during the long maintenance period in 2018 and 2019. As possible technology for these New Small Wheels, high-rate capable sMDT drift tubes have been investigated, based on the ATLAS 30 mm Monitored Drift Tube technology, but with a smaller diameter of 15 mm. In this work, a prototype sMDT chamber has been tested under the influence of high-rate irradiation with protons, neutrons and photons at the Munich tandem accelerator, simulating the conditions within a high luminosity LHC experiment. Tracking resolution and detection efficiency for minimum ionizing muons are presented as a function of irradiation rate. The experimental muon trigger geometry allows to distinguish between efficiency degradation due to deadtime effects and space charge in the detectors. Using modified readout electronics the analog pulse shape of the detector has been investigated for gain reduction and potential irregularities due to the high irradiation rates and ionization doses. This study shows that the sMDT detectors would fulfill all requirements for successful use in the ATLAS New Small Wheel endcap detector array, with an average spatial resolution of 140 μm and a track reconstruction efficiency

TCAD simulation of Low Gain Avalanche Detectors

Science.gov (United States)

Dalal, Ranjeet; Jain, Geetika; Bhardwaj, Ashutosh; Ranjan, Kirti

2016-11-01

In the present work, detailed simulation using Technology Computer Aided Design (TCAD) tool, Silvaco for non-irradiated and irradiated LGAD (Low Gain Avalanche Detector) devices has been carried out. The effects of different design parameters and proton irradiation on LGAD operation are discussed in detail. An already published effective two trap bulk damage model is used to simulate the radiation damage without implementing any acceptor removal term. The TCAD simulation for irradiated LGAD devices produce decreasing gain with increasing fluence, similar to the measurement results. The space charge density and electric field distribution are used to illustrate the possible reasons for the degradation of gain of the irradiated LGAD devices.

TCAD simulation of Low Gain Avalanche Detectors

Energy Technology Data Exchange (ETDEWEB)

Dalal, Ranjeet; Jain, Geetika; Bhardwaj, Ashutosh, E-mail: ashutosh.bhardwaj@cern.ch; Ranjan, Kirti

2016-11-11

In the present work, detailed simulation using Technology Computer Aided Design (TCAD) tool, Silvaco for non-irradiated and irradiated LGAD (Low Gain Avalanche Detector) devices has been carried out. The effects of different design parameters and proton irradiation on LGAD operation are discussed in detail. An already published effective two trap bulk damage model is used to simulate the radiation damage without implementing any acceptor removal term. The TCAD simulation for irradiated LGAD devices produce decreasing gain with increasing fluence, similar to the measurement results. The space charge density and electric field distribution are used to illustrate the possible reasons for the degradation of gain of the irradiated LGAD devices.

TCAD simulation of Low Gain Avalanche Detectors

International Nuclear Information System (INIS)

Dalal, Ranjeet; Jain, Geetika; Bhardwaj, Ashutosh; Ranjan, Kirti

2016-01-01

In the present work, detailed simulation using Technology Computer Aided Design (TCAD) tool, Silvaco for non-irradiated and irradiated LGAD (Low Gain Avalanche Detector) devices has been carried out. The effects of different design parameters and proton irradiation on LGAD operation are discussed in detail. An already published effective two trap bulk damage model is used to simulate the radiation damage without implementing any acceptor removal term. The TCAD simulation for irradiated LGAD devices produce decreasing gain with increasing fluence, similar to the measurement results. The space charge density and electric field distribution are used to illustrate the possible reasons for the degradation of gain of the irradiated LGAD devices.

Characterization of irradiation induced deep and shallow impurities

Science.gov (United States)

Treberspurg, Wolfgang; Bergauer, Thomas; Dragicevic, Marko; Krammer, Manfred; Valentan, Manfred

2013-12-01

Silicon Detectors close to the interaction point of the High Luminosity Large Hardron Collider (HL-LHC) have to withstand a harsh irradiation environment. In order to evaluate the behaviour of shallow and deep defects, induced by neutron irradiation, spreading resistance resistivity measurements and capacitance voltage measurements have been performed. These measurements, deliver information about the profile of shallow impurities after irradiation as well as indications of deep defects in the Space Charge Region (SCR) and the Electrical Neutral Bulk (ENB). By considering the theoretical background of the measurement both kinds of defects can be investigated independently from each other.

Characterization of irradiation induced deep and shallow impurities

Energy Technology Data Exchange (ETDEWEB)

Treberspurg, Wolfgang, E-mail: wolfgang.treberspurg@oeaw.ac.at; Bergauer, Thomas; Dragicevic, Marko; Krammer, Manfred; Valentan, Manfred

2013-12-21

Silicon Detectors close to the interaction point of the High Luminosity Large Hardron Collider (HL-LHC) have to withstand a harsh irradiation environment. In order to evaluate the behaviour of shallow and deep defects, induced by neutron irradiation, spreading resistance resistivity measurements and capacitance voltage measurements have been performed. These measurements, deliver information about the profile of shallow impurities after irradiation as well as indications of deep defects in the Space Charge Region (SCR) and the Electrical Neutral Bulk (ENB). By considering the theoretical background of the measurement both kinds of defects can be investigated independently from each other.

Characterization of irradiation induced deep and shallow impurities

International Nuclear Information System (INIS)

Treberspurg, Wolfgang; Bergauer, Thomas; Dragicevic, Marko; Krammer, Manfred; Valentan, Manfred

2013-01-01

Silicon Detectors close to the interaction point of the High Luminosity Large Hardron Collider (HL-LHC) have to withstand a harsh irradiation environment. In order to evaluate the behaviour of shallow and deep defects, induced by neutron irradiation, spreading resistance resistivity measurements and capacitance voltage measurements have been performed. These measurements, deliver information about the profile of shallow impurities after irradiation as well as indications of deep defects in the Space Charge Region (SCR) and the Electrical Neutral Bulk (ENB). By considering the theoretical background of the measurement both kinds of defects can be investigated independently from each other

Deep defect levels in standard and oxygen enriched silicon detectors before and after **6**0Co-gamma-irradiation

CERN Document Server

Stahl, J; Lindström, G; Pintilie, I

2003-01-01

Capacitance Deep Level Transient Spectroscopy (C-DLTS) measurements have been performed on standard and oxygen-doped silicon detectors manufactured from high-resistivity n-type float zone material with left angle bracket 111 right angle bracket and left angle bracket 100 right angle bracket orientation. Three different oxygen concentrations were achieved by the so-called diffusion oxygenated float zone (DOFZ) process initiated by the CERN-RD48 (ROSE) collaboration. Before the irradiation a material characterization has been performed. In contrast to radiation damage by neutrons or high- energy charged hadrons, were the bulk damage is dominated by a mixture of clusters and point defects, the bulk damage caused by **6**0Co-gamma-radiation is only due to the introduction of point defects. The dominant electrically active defects which have been detected after **6**0Co-gamma-irradiation by C-DLTS are the electron traps VO//i, C//iC//s, V//2( = /-), V //2(-/0) and the hole trap C//i O//i. The main difference betwe...

Plasma measurements with surface barrier detectors

International Nuclear Information System (INIS)

Futch, A.H. Jr.; Bradley, A.E.

1969-01-01

A surface barrier detector system for measuring the loss rate of protons from a hydrogen plasma and their energy spectrum is described. A full width at half maximum (FWHM) resolution of 1.4 keV for 15-keV hydrogen atoms was obtained using a selected detector having a sensitive area of 3 mm 2 and a depletion depth of 700 microns

Test of radiation hardness of pcCVD detectors

Energy Technology Data Exchange (ETDEWEB)

Schlemme, Steffen [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Technische Universitaet Darmstadt (Germany); Enders, Joachim [Technische Universitaet Darmstadt (Germany); Figuera, P.; Salamone, S. [LNS-INFN Catania (Italy); Fruehauf, J.; Kis, Mladen; Kratz, A.; Kurz, N.; Loechner, S.; Nociforo, Chiara; Schirru, Fabio; Szczepanczyk, B.; Traeger, M.; Visinka, R. [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Musumarra, A. [LNS-INFN Catania (Italy); University of Catania (Italy)

2016-07-01

The new in-flight separator Super-FRS is under construction at the Facility for Antiproton and Ion Research (FAIR, Darmstadt). Ion rates up to 3 x 10{sup 11} {sup 238}U/spill demand an adaption of detectors to a high radiation environment. A test experiment to investigate the radiation hardness of polycrystalline diamond detectors (pcCVD) was performed at the LNS-INFN in Catania using a {sup 12}C beam at 62 MeV/u and intensities of up to 1.5 pnA. The setup consisted of pcCVD strip detectors to measure the beam profile, a single crystal diamond detector to calibrate the ionisation chamber working in current mode as a beam intensity monitor and a pcCVD sample to be irradiated. The IC used was designed for FAIR and showed a stable counting rate allowing us to calibrate and perform beam intensity measurements with it. The total measured counts on the sample were 8.25 x 10{sup 11} counts/mm{sup 2} over a period of 60 hours. Digital waveforms of the pcCVD signals were taken with an oscilloscope and analysed. The results showed no change of the pcCVD signal properties during the entire irradiation.

Measurements on a prototype segmented Clover detector

CERN Document Server

Shepherd, S L; Cullen, D M; Appelbe, D E; Simpson, J; Gerl, J; Kaspar, M; Kleinböhl, A; Peter, I; Rejmund, M; Schaffner, H; Schlegel, C; France, G D

1999-01-01

The performance of a segmented Clover germanium detector has been measured. The segmented Clover detector is a composite germanium detector, consisting of four individual germanium crystals in the configuration of a four-leaf Clover, housed in a single cryostat. Each crystal is electrically segmented on its outer surface into four quadrants, with separate energy read-outs from nine crystal zones. Signals are also taken from the inner contact of each crystal. This effectively produces a detector with 16 active elements. One of the purposes of this segmentation is to improve the overall spectral resolution when detecting gamma radiation emitted following a nuclear reaction, by minimising Doppler broadening caused by the opening angle subtended by each detector element. Results of the tests with sources and in beam will be presented. The improved granularity of the detector also leads to an improved isolated hit probability compared with an unsegmented Clover detector. (author)

Comparison and limitations of three different bulk etch rate measurement methods used for gamma irradiated PM-355 detectors

Energy Technology Data Exchange (ETDEWEB)

Fazal-ur-Rehman E-mail: fazalr@kfupm.edu.sa; Abu-Jarad, F.; Al-Jarallah, M.I.; Farhat, M

2001-06-01

Samples of Nuclear Track Detectors (PM-355) were exposed to high gamma doses from 1x10{sup 5} Gy (10 Mrad) up to 1.2x10{sup 6} Gy (120 Mrad) at an incremental dose of 1x10{sup 5} Gy (10 Mrad). The gamma source was a 9.03 PBq (244 kCi) Co-60 source used for sterilization of medical syringes. The bulk etch rate (V{sub b}) was measured for various high gamma doses by three different methods: 1--thickness change method; 2--mass change method; 3--fission track diametric method. The study gives a comparison and limitations of these three methods used for bulk etch rate measurements in the detectors as a function of high gamma doses. The track etch rate (V{sub t}) and the sensitivity (V) of the detector were also measured using the fission track diametric method. It was observed that V{sub b} increases with the increase of the gamma absorbed dose at a fixed etching time in each bulk etch measuring method. The bulk etch rate decreases exponentially with the etching time at a fixed gamma absorbed dose in all three methods. The thickness change and mass change methods have successfully been applied to measure V{sub b} at higher gamma doses up to 1.2x10{sup 6} Gy (120 Mrad). The bulk etch rate determined by the mass change and thickness change methods was almost the same at a certain gamma dose and etching time whereas it was quite low in the case of the fission track diametric method due to its limitations at higher doses. Also in this method it was not possible to measure the fission fragment track diameters at higher doses due to the quick disappearance of the fission tracks and therefore the V{sub b} could not be estimated at higher gamma doses.

Space charge sign inversion and electric field reconstruction in 24 GeV/c proton-irradiated MCZ Si p+-n(TD)-n+ detectors processed via thermal donor introduction

International Nuclear Information System (INIS)

Li, Z.; Verbitskaya, E.; Carini, G.; Chen, W.; Eremin, V.; Gul, R.; Haerkoenen, J.; Li, M.

2009-01-01

The aim of this study is the evaluation of radiation effects in detectors based on p-type magnetic czochralski (MCZ) Si that was converted to n-type by thermal donor (TD) introduction. As-processed p + -p-n + detectors were annealed at 430 deg. C resulting in p + -n(TD)-n + structures. The space charge sign and the electric field distribution E(x) in MCz Si p + -n(TD)-n + detectors irradiated by 24 GeV/c protons were analyzed using the data on the current pulse response and the Double Peak (DP) electric field distribution model for heavily irradiated detectors. The approach considers an irradiated detector as a structure with three regions in which the electric field depends on the coordinate, and the induced current pulse response arises from the drift process of free carriers in the detector with variable electric field. Reconstruction of the E(x) profile from the pulse response shapes is performed employing a new method for DP electric field reconstruction. This method includes: (a) a direct extraction of charge loss due to trapping and (b) the fitting of a simulated pulse response to the 'corrected' pulse by adjusting the electric field profiles in the three regions. Reconstruction of E(x) distribution showed that in the diodes irradiated by a proton fluence of (2-4)x10 14 p/cm 2 space charge sign inversion has occurred. This is the evidence that the influence of 24 GeV/c proton radiation on MCz Si p + -n(TD)-n + detectors is similar to that on p + -n-n + detectors based on FZ or diffusion oxygenated n-type Si.

Plastic scintillator detector for pulsed flux measurements

International Nuclear Information System (INIS)

Kadilin, V V; Kaplun, A A; Taraskin, A A

2017-01-01

A neutron detector, providing charged particle detection capability, has been designed. The main purpose of the detector is to measure pulsed fluxes of both charged particles and neutrons during scientific experiments. The detector consists of commonly used neutron-sensitive ZnS(Ag) / 6 LiF scintillator screens wrapping a layer of polystyrene based scintillator (BC-454, EJ-254 or equivalent boron loaded plastic). This type of detector design is able to log a spatial distribution of events and may be scaled to any size. Different variations of the design were considered and modelled in specialized toolkits. The article presents a review of the detector design features as well as simulation results. (paper)

Performance of the ALIBAVA portable readout system with irradiated and non-irradiated microstrip silicon sensors

International Nuclear Information System (INIS)

Marco-Hernadez, R.

2009-01-01

A readout system for microstrip silicon sensors has been developed as a result of collaboration among the University of Liverpool, the CNM of Barcelona and the IFIC of Valencia. The name of this collaboration is ALIBAVA and it is integrated in the RD50 Collaboration. This system is able to measure the collected charge in one or two microstrip silicon sensors by reading out all the channels of the sensor(s), up to 256, as an analogue measurement. The system uses two Beetle chips to read out the detector(s). The Beetle chip is an analogue pipelined readout chip used in the LHCb experiment. The system can operate either with non-irradiated and irradiated sensors as well as with n-type and p-type microstrip silicon sensors. Heavily irradiated sensors will be used at the SLHC, so this system is being to research the performance of microstrip silicon sensors in conditions as similar as possible to the SLHC operating conditions. The system has two main parts: a hardware part and a software part. The hardware part acquires the sensor signals either from external trigger inputs, in case of a radioactive source setup is used, or from a synchronised trigger output generated by the system, if a laser setup is used. This acquired data is sent by USB to be stored in a PC for a further processing. The hardware is a dual board based system. The daughterboard is a small board intended for containing two Beetle readout chips as well as fan-ins and detector support to interface the sensors. The motherboard is intended to process the data, to control the whole hardware and to communicate with the software by USB. The software controls the system and processes the data acquired from the sensors in order to store it in an adequate format file. The main characteristics of the system will be described. Results of measurements acquired with n-type and p-type irradiated and non-irradiated detectors using both the laser and the radioactive source setup will be also presented and discussed

Studies on nitrogen mapping by various CR-39 track detectors

Energy Technology Data Exchange (ETDEWEB)

Somogyi, G.; Varga, Zs.; Hunyadi, I.; Freyer, K.; Treutler, H.Ch.

1986-01-01

The use of CR-39 track detectors for nitrogen distribution measurements via the /sup 14/N(n,p)/sup 14/C reaction is studied. The proton detection properties of different CR-39 products have been analyzed. The variation of background track density induced in the bulk of detectors is examined under different conditions of neutron irradiation. Analysis of our experimental data has led to the conclusion that the sources of proton background tracks are the fast neutron component of the neutron source, chlorine impurities in the detector and nitrogen diffused from the air into the upper layer of the detector. Efforts have been made to decrease the nitrogen content of diffusion origin by removing the upper detector layer and by outgassing the CR-39 sheet in vacuum before irradiation. Finally the ''signal/noise'' ratio for a steel specimen and the sensitivity of nitrogen determination are given.

Detection of irradiated potatoes by impedance measurement

International Nuclear Information System (INIS)

Hayashi, T.; Todoriki, S.; Otobe, K.; Sugiyama, J.

1996-01-01

Potato is one of the major food items to be treated with ionising radiation and potatoes are irradiated on a large scale in several countries. Every year around 15,000 t of potatoes are irradiated at doses of 60 to 150 Gy (average dose is about 100 Gy) in Japan. Although various methods to detect irradiated potatoes have been investigated, no established method has been reported. Measuring electrical conductivity or impedance of potatoes has been reported as a promising method for the detection of irradiated potatoes. In previous studies it has been found that the ratio of impedance magnitude at 50 kHz to that at 5 kHz, measured immediately after puncturing a potato tuber, is dependent upon the dose applied to the tuber, independent of storage temperature and stable during storage after irradiation. The aim of this study was to establish the optimum conditions for impedance measurement and to examine the applicability of the impedance measuring method to various cultivars (cv.) of potatoes. (author)

Double Chooz Improved Multi-Detector Measurements

CERN Multimedia

CERN. Geneva

2016-01-01

The Double Chooz experiment (DC) is a reactor neutrino oscillation experiment running at Chooz nuclear power plant (2 reactors) in France. In 2011, DC first reported indication of non-zero θ13 with the far detector (FD) located at the maximum of oscillation effects (i.e. disappearance), thus challenging the CHOOZ non-observation limit. A robust observation of θ13 followed in 2012 by the Daya Bay experiments with multiple detector configurations. Since 2015 DC runs in a multi-detector configuration making thus the impact of several otherwise dominating systematics reduce strongly. DC’s unique almost "iso-flux" site, allows the near detector (ND) to become a direct accurate non-oscillation reference to the FD. Our first multi-detector results at MORIOND-2016 showed an intriguing deviation of θ13 with respect to the world average. We will address this issue in this seminar. The combined "reactor-θ13" measurement is expected to ...

Fast neutron activating detectors for pulsed flow measurements

International Nuclear Information System (INIS)

Dyatlov, V.D.; Kunaev, G.T.; Popytaev, A.N.; Cheremukhov, B.V.

1979-01-01

The requirements to the activation detectors of the pulsed flows of the fast neutrons are considered; the criteria of optimum measurement time, geometrical moderator sizes and radioactive detector element properties have been obtained. On their analysis parameter selection has been carried out. The neutron detector to register the short pulses has been designed and calibrated. The ways of further increase of sensitivity and efficiency of such detectors are discussed

Measurement and protection of the oxidative damage induced by heavy-ion irradiation in human glioblastoma cell lines

International Nuclear Information System (INIS)

Moritake, Takashi; Tsuboi, Koji; Nose, Tadao

2003-01-01

The aim of this study is to evaluate the oxidative damage of DNA caused by low or high linear energy transfer (LET) radiation by measuring the level of 8-hydroxydeoxyguanosine (8-OHdG). Relationship between the 8-OHdG level and the LET value was assessed, and the anti-oxidative effect of 3-methyl-1-phenyl-2-pyrazolin-5-one (edaravone) on DNA was evaluated as well. Solution containing salmon sperm DNA at a concentration of 1.0 mg/ml was irradiated with 10 Gy of x-ray or 290 MeV/u carbon beams with an LET range of 20-80 keV/μm. The 8-OHdG level in the DNA solution was measured by high performance liquid chromatography (HPLC) with an electrochemical detector (ECD) after each irradiation. Edaravone was added to the DNA solution in final concentrations from 10 μM to 1 mM and 8-OHdG level was measured by the same method after irradiation. The level of 8-OHdG increased dose-dependently after x-rays irradiation, and it was significantly suppressed by the presence of edaravone. The yield of 8-OHdG decreased as LET value increased, and the protection efficiency by edaravone decreased as LET value increased. (author)

Measurement and protection of the oxidative damage induced by heavy-ion irradiation in human glioblastoma cell lines

Energy Technology Data Exchange (ETDEWEB)

Moritake, Takashi; Tsuboi, Koji; Nose, Tadao [Tsukuba Univ., Ibaraki (Japan). Inst. of Clinical Medicine; Anzai, Kazunori; Ikota, Nobuo; Ando, Koichi; Ozawa, Toshihiko [National Inst. of Radiological Sciences, Chiba (Japan)

2003-04-01

The aim of this study is to evaluate the oxidative damage of DNA caused by low or high linear energy transfer (LET) radiation by measuring the level of 8-hydroxydeoxyguanosine (8-OHdG). Relationship between the 8-OHdG level and the LET value was assessed, and the anti-oxidative effect of 3-methyl-1-phenyl-2-pyrazolin-5-one (edaravone) on DNA was evaluated as well. Solution containing salmon sperm DNA at a concentration of 1.0 mg/ml was irradiated with 10 Gy of x-ray or 290 MeV/u carbon beams with an LET range of 20-80 keV/{mu}m. The 8-OHdG level in the DNA solution was measured by high performance liquid chromatography (HPLC) with an electrochemical detector (ECD) after each irradiation. Edaravone was added to the DNA solution in final concentrations from 10 {mu}M to 1 mM and 8-OHdG level was measured by the same method after irradiation. The level of 8-OHdG increased dose-dependently after x-rays irradiation, and it was significantly suppressed by the presence of edaravone. The yield of 8-OHdG decreased as LET value increased, and the protection efficiency by edaravone decreased as LET value increased. (author)

Neutron activation detector saturation activities measured in the AAEC research reactor HIFAR

International Nuclear Information System (INIS)

Hilditch, R.J.; Lowenthal, G.C.

1980-01-01

Titanium and cobalt wires are irradiated with radiation damage specimens in each reactor period to determine variations in neutron flux densities. The results from these monitors constitute a considerable body of data with good statistical significance. However, a difficulty encountered when using measurements collected over a number of reactor periods for determining flux depression factors or cadmium ratios is accounting for the effects on saturation activities of different irradiation conditions, in particular the continuously changing fuel burn-up rates. This difficulty was overcome by correlating the saturation activities of (n,γ) reactions with the number of fissions in the fuel. The experimental saturation activities so correlated enable (1) flux depression factors to be obtained for cobalt and silver wires, relative to thin foils, and (2) use of these flux depression factors and others quoted in the literature to calculate the ratio of saturation activities of Co and Ag wires. Finally, reference is made to the potential usefulness of the 123 Sb(n,γ) reaction as a resonance detector given that a new method for making thin monitors can be readily applied to antimony

Radiation damage in silicon detectors

CERN Document Server

Lindström, G

2003-01-01

Radiation damage effects in silicon detectors under severe hadron and gamma-irradiation are surveyed, focusing on bulk effects. Both macroscopic detector properties (reverse current, depletion voltage and charge collection) as also the underlying microscopic defect generation are covered. Basic results are taken from the work done in the CERN-RD48 (ROSE) collaboration updated by results of recent work. Preliminary studies on the use of dimerized float zone and Czochralski silicon as detector material show possible benefits. An essential progress in the understanding of the radiation-induced detector deterioration had recently been achieved in gamma irradiation, directly correlating defect analysis data with the macroscopic detector performance.

Effect of trapping of charge carriers on the resolution of Ge(Li) detectors

International Nuclear Information System (INIS)

Venturini, Luzia

1979-01-01

In this work a measurement is described of the variation of the resolution of a Ge(Li) detector as a function of the position of irradiation of a collimated gamma-ray beam. Also the variation of the resolution has been measured as a function of the applied detector voltage, using a collimated and a non-collimated gamma-ray beam. The measurement indicate that in the process of charge collection loss of holes predominates and the best resolution is obtained in the middle of the compensated region. It has been verified that, in the case of a collimated gamma beam the detector resolution improves with increasing detector bias up to at least 5100 Volts. For a non-collimated gamma beam, however, the resolution reaches a constant value at about 4400 Volts. The dependence of resolution on the position of irradiation can be accounted for by introducing a local ionization factor different from the usual position independent Fano factor. (author)

Ultrafast photoconductive detector-laser-diode transmitter

International Nuclear Information System (INIS)

Wang, C.L.; Davies, T.J.; Nelson, M.A.; Thomas, M.C.; Zagarino, P.A.; Davis, B.A.

1987-01-01

The authors report the results of an experiment in which they used an ultrafast, photoconductive, radiation detector to drive a fast laser-diode transmitter. When they irradiated the neutron-damaged Cr-doped Ga/As detector with 17-MeV electron beams, the temporal response of was measured to be less than 30 ps. The pulses from this detector modulated a fast GaAlAs laser diode to transmit the laser output through 30- and 1100-m optical fibers. Preliminary results indicate that 50- and 80-ps time resolutions, respectively, are obtainable with these fibers. They are now working to integrate the photoconductive detector and the laser diode transmitter into a single chip

Hexagonal boron nitride neutron detectors with high detection efficiencies

Science.gov (United States)

Maity, A.; Grenadier, S. J.; Li, J.; Lin, J. Y.; Jiang, H. X.

2018-01-01

Neutron detectors fabricated from 10B enriched hexagonal boron nitride (h-10BN or h-BN) epilayers have demonstrated the highest thermal neutron detection efficiency among solid-state neutron detectors to date at about 53%. In this work, photoconductive-like vertical detectors with a detection area of 1 × 1 mm2 were fabricated from 50 μm thick free-standing h-BN epilayers using Ni/Au and Ti/Al bilayers as ohmic contacts. Leakage currents, mobility-lifetime (μτ) products under UV photoexcitation, and neutron detection efficiencies have been measured for a total of 16 different device configurations. The results have unambiguously identified that detectors incorporating the Ni/Au bilayer on both surfaces as ohmic contacts and using the negatively biased top surface for neutron irradiation are the most desired device configurations. It was noted that high growth temperatures of h-10BN epilayers on sapphire substrates tend to yield a higher concentration of oxygen impurities near the bottom surface, leading to a better device performance by the chosen top surface for irradiation than by the bottom. Preferential scattering of oxygen donors tends to reduce the mobility of holes more than that of electrons, making the biasing scheme with the ability of rapidly extracting holes at the irradiated surface while leaving the electrons to travel a large average distance inside the detector at a preferred choice. When measured against a calibrated 6LiF filled micro-structured semiconductor neutron detector, it was shown that the optimized configuration has pushed the detection efficiency of h-BN neutron detectors to 58%. These detailed studies also provided a better understanding of growth-mediated impurities in h-BN epilayers and their effects on the charge collection and neutron detection efficiencies.

47 CFR 15.35 - Measurement detector functions and bandwidths.

Science.gov (United States)

2010-10-01

... are based on the use of measurement instrumentation employing an average detector function. Unless... in terms of the average value of the emission, and pulsed operation is employed, the measurement... 47 Telecommunication 1 2010-10-01 2010-10-01 false Measurement detector functions and bandwidths...

Spent-fuel characterization with small CZT detectors

Energy Technology Data Exchange (ETDEWEB)

Berndt, R. [European Commission, Joint Research Centre, Ispra, 21020 Ispra (Vatican City State, Holy See,) (Italy)]. E-mail: Reinhard.Berndt@jrc.it; Mortreau, P. [European Commission, Joint Research Centre, Ispra, 21020 Ispra (Va) (Italy)

2006-08-01

CdTe detectors may be utilised as miniature instruments for the measurement of gamma spectra in safeguards applications [R. Arlt, V. Gryshchuk, P. Sumah, Nucl. Instr. and Meth. A 428 (1999) 127]. This is applicable for measurements both to fresh fuel and irradiated nuclear fuel. The spectrum analysis, however, is more complicated than with Ge detectors. Some reasons are: the peaks are asymmetric, the peak/Compton ratio is low, peak parameters depend on the count rate and on the properties of individual detector crystals. We developed a spectrum-unfolding code for spectra obtained with CdTe detectors. The code makes use of a series of pattern spectra of the individual instrument. It is applied to fission-product spectra and allows the coarse characterisation of the spent fuel in safeguards inspections.

Spent-fuel characterization with small CZT detectors

International Nuclear Information System (INIS)

Berndt, R.; Mortreau, P.

2006-01-01

CdTe detectors may be utilised as miniature instruments for the measurement of gamma spectra in safeguards applications [R. Arlt, V. Gryshchuk, P. Sumah, Nucl. Instr. and Meth. A 428 (1999) 127]. This is applicable for measurements both to fresh fuel and irradiated nuclear fuel. The spectrum analysis, however, is more complicated than with Ge detectors. Some reasons are: the peaks are asymmetric, the peak/Compton ratio is low, peak parameters depend on the count rate and on the properties of individual detector crystals. We developed a spectrum-unfolding code for spectra obtained with CdTe detectors. The code makes use of a series of pattern spectra of the individual instrument. It is applied to fission-product spectra and allows the coarse characterisation of the spent fuel in safeguards inspections

Three types of photon detectors for in situ measurements

Science.gov (United States)

Helmer, R. G.; Gehrke, R. J.; Carpenter, M. V.

1999-02-01

The authors have been involved in the calibration and use of three types of γ- and X-ray detectors for in situ measurements of soil contamination. These three detectors are an N-type, thin-window Ge semiconductor detector (5.0 cm diam.× 2.0 cm deep), a plastic scintillator (30.5 cm × 30.5 cm × 3.8 cm thick), and an array of six CaF 2 detectors (each 7.6 cm × 7.6 cm × 0.15 cm thick). The latter two detectors have been used with scanning systems that allow significant areas (say, >100 m 2) to be surveyed completely with the aid of either laser-based triangulation or a global positioning system (GPS) to record the precise position for each measurement. Typically, these systems scan at a rate of 15-30 cm/s which allows an area of 100 m 2 to covered with the plastic scintillator in about 15 min. The data are telemetered or transferred via RS232 protocol to a computer, providing operators with real-time mapping of the area surveyed and of the measured detector count rate. The "efficiencies" of these detectors have been determined by a combination of measurements of calibrated planar sources and Monte Carlo transport calculations for a variety of source sizes and depths in soil, as well as by comparing these field measurements with independent laboratory sample analysis.

Measurements of fast neutrons by bubble detectors

Energy Technology Data Exchange (ETDEWEB)

Castillo, F.; Martinez, H. [Laboratorio de Espectroscopia, Instituto de Ciencias Fisicas, Universidad Nacional Autonoma de Mexico, Apartado Postal 48-3, 62251, Cuernavaca Morelos (Mexico); Leal, B. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-543, 04510, Ciudad Universitaria, Mexico D. F. (Mexico); Rangel, J. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-543, 04510, Ciudad Universitaria, Mexico D. F (Mexico); Reyes, P. G. [Facultad de Ciencias, Universidad Autonoma del Estado de Mexico, Instituto Literario 100, Col. Centro, 50000, Toluca Estado de Mexico (Mexico)

2013-07-03

Neutron bubble detectors have been studied using Am-Be and D-D neuron sources, which give limited energy information. The Bubble Detector Spectrometer (BDS) have six different energy thresholds ranging from 10 KeV to 10 Mev. The number of bubbles obtained in each measurement is related to the dose (standardized response R) equivalent neutrons through sensitivity (b / {mu}Sv) and also with the neutron flux (neutrons per unit area) through a relationship that provided by the manufacturer. Bubble detectors were used with six different answers (0.11 b/ {mu}Sv, 0093 b/{mu}Sv, 0.14 b/{mu}Sv, 0.17 b/{mu}Sv, 0051 b/{mu}Sv). To test the response of the detectors (BDS) radiate a set of six of them with different energy threshold, with a source of Am-Be, placing them at a distance of one meter from it for a few minutes. Also, exposed to dense plasma focus Fuego Nuevo II (FN-II FPD) of ICN-UNAM, apparatus which produces fusion plasma, generating neutrons by nuclear reactions of neutrons whose energy emitting is 2.45 MeV. In this case the detectors were placed at a distance of 50 cm from the pinch at 90 Degree-Sign this was done for a certain number of shots. In both cases, the standard response is reported (Dose in {mu}Sv) for each of the six detectors representing an energy range, this response is given by the expression R{sub i}= B{sub i} / S{sub i} where B{sub i} is the number of bubbles formed in each and the detector sensitivity (S{sub i}) is given for each detector in (b / {mu}Sv). Also, reported for both cases, the detected neutron flux (n cm{sup -2}), by a given ratio and the response involves both standardized R, as the average cross section sigma. The results obtained have been compared with the spectrum of Am-Be source. From these measurements it can be concluded that with a combination of bubble detectors, with different responses is possible to measure the equivalent dose in a range of 10 to 100 {mu}Sv fields mixed neutron and gamma, and pulsed generated fusion

Position-sensitive silicon strip detector characterization using particle beams

CERN Document Server

Maenpaeae, Teppo

2012-01-01

Silicon strip detectors are fast, cost-effective and have an excellent spatial resolution.They are widely used in many high-energy physics experiments. Modern high energyphysics experiments impose harsh operation conditions on the detectors, e.g., of LHCexperiments. The high radiation doses cause the detectors to eventually fail as a resultof excessive radiation damage. This has led to a need to study radiation tolerance usingvarious techniques. At the same time, a need to operate sensors approaching the endtheir lifetimes has arisen.The goal of this work is to demonstrate that novel detectors can survive the environment that is foreseen for future high-energy physics experiments. To reach this goal,measurement apparatuses are built. The devices are then used to measure the propertiesof irradiated detectors. The measurement data are analyzed, and conclusions are drawn.Three measurement apparatuses built as a part of this work are described: two telescopes measuring the tracks of the beam of a particle acceler...

Study of intense pulse irradiation effects on silicon targets considered as ground matter for optical detectors

International Nuclear Information System (INIS)

Muller, O.

1994-12-01

This study aim was centered on morphological and structural alterations induced by laser irradiation on silicon targets considered as ground matter for optical detectors. First we recalled the main high light intensity effects on the condensed matter. Then we presented the experimental aspects. The experimental studies were achieved on two sample types: SiO 2 /Si and Si. Two topics were studied: the defect chronology according to wavelength and pulse length, and the crystalline quality as well as the structure defects of irradiated zones by Raman spectroscopy. Finally, irradiation of Si targets by intense pulsed beams may lead to material fusion. This phenomenon is particularly easy when the material is absorbent, when the pulse is short and when the material is superficially oxidized. (MML). 204 refs., 93 figs., 21 tabs., 1 appendix

Radiation hardness of a single crystal CVD diamond detector for MeV energy protons

Energy Technology Data Exchange (ETDEWEB)

Sato, Yuki, E-mail: y.sato@riken.jp [The Institute of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Shimaoka, Takehiro; Kaneko, Junichi H. [Graduate School of Engineering, Hokkaido University, N13, W8, Sapporo 060-8628 (Japan); Murakami, Hiroyuki [The Institute of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Isobe, Mitsutaka; Osakabe, Masaki [National Institute for Fusion Science, 322-6, Oroshi-cho Toki-city, Gifu 509-5292 (Japan); Tsubota, Masakatsu [Graduate School of Engineering, Hokkaido University, N13, W8, Sapporo 060-8628 (Japan); Ochiai, Kentaro [Fusion Research and Development Directorate, Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Chayahara, Akiyoshi; Umezawa, Hitoshi; Shikata, Shinichi [National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577 (Japan)

2015-06-01

We have fabricated a particle detector using single crystal diamond grown by chemical vapor deposition. The irradiation dose dependence of the output pulse height from the diamond detector was measured using 3 MeV protons. The pulse height of the output signals from the diamond detector decreases as the amount of irradiation increases at count rates of 1.6–8.9 kcps because of polarization effects inside the diamond crystal. The polarization effect can be cancelled by applying a reverse bias voltage, which restores the pulse heights. Additionally, the radiation hardness performance for MeV energy protons was compared with that of a silicon surface barrier detector.

Influence of damage caused by Kr ions and neutrons on electrical properties of silicon detectors

CERN Document Server

Croitoru, N; Rancoita, P G; Rattaggi, M; Seidman, A

1999-01-01

In this paper, new measurements of physical properties of high-resistivity silicon, used in high-energy detectors, are presented. The obtained data contribute to the understanding of the causes which damage the 2electronic characteristics of the detection systems under irradiation of neutrons and ionized particles (Kr). The Hall effect coefficient (R sub H) and resistivity (rho) measurements as a function of temperature (T), for non-irradiated and irradiated by neutrons and Kr ions, were performed. The measurements of the Hall coefficient and resistivity of non-irradiated samples and irradiated at neutron fluences (PHI=9.9x10 sup 1 sup 0 n/cm sup 2 (neutrons) and PHI>=7.5x10 sup 8 Kr/cm sup 3 (ions), cannot be explained, considering the usual theoretical relations. The results, obtained in these experiments, have shown a change of mechanism of conduction due to the damaged regions, where localized levels are created, which are the main cause of the deviation of the electrical characteristics of the detectors ...

An X-Ray facility to perform irradiation tests and TID studies on electronics and detectors

CERN Document Server

Brundu, Davide; Cadeddu, Sandro; Wyllie, Ken; Ciambrone, Paolo

2018-01-01

The X-Ray irradiation system of the LHCb group, installed in Cagliari, is presented; with a particular focus on the setup configuration and dose rate calibration. The system can be used to perform Total Ionizing Dose (TID) studies for detectors, readout and front-end electronics. It was already used to test the nSYNC chip, an ASIC for the readout of the LHCb upgraded muon system.

Time response measurements of LASL diagnostic detectors

International Nuclear Information System (INIS)

Hocker, L.P.

1970-07-01

The measurement and data analysis techniques developed under the Los Alamos Scientific Laboratory's detector improvement program were used to characterize the time and frequency response of selected LASL Compton, fluor-photodiode (NPD), and fluor-photomultiplier (NPM) diagnostic detectors. Data acquisition procedures and analysis methods presently in use are summarized, and detector time and frequency data obtained using the EG and G/AEC electron linear accelerator fast pulse (approximately 50 psec FWHM) as the incident radiation driving function are presented. (U.S.)

Detection of irradiated potatoes by conductivity measurements

International Nuclear Information System (INIS)

Scherz, H.

1991-01-01

In this paper, the author shows that the conductivity of irradiated potatoes measured by a sticking electrode depend on the irradiation dose and is independent on the potato variety. The measured values remain constant over a six month storage period

Radiation damage measurements in room temperature semiconductor radiation detectors

International Nuclear Information System (INIS)

Franks, L.A.; Olsen, R.W.; James, R.B.; Brunett, B.A.; Walsh, D.S.; Doyle, B.L.; Vizkelethy, G.; Trombka, J.I.

1998-01-01

The literature of radiation damage measurements on cadmium zinc telluride (CZT), cadmium telluride (CT), and mercuric iodide (HgI 2 ) is reviewed and in the case of CZT supplemented by new alpha particle data. CZT strip detectors exposed to intermediate energy (1.3 MeV) proton fluences exhibit increased interstrip leakage after 10 10 p/cm 2 and significant bulk leakage after 10 12 p/cm 2 . CZT exposed to 200 MeV protons shows a two-fold loss in energy resolution after a fluence of 5 x 10 9 p/cm 2 in thick (3 mm) planar devices but little effect in 2 mm devices. No energy resolution effects were noted from moderated fission spectrum of neutrons after fluences up to 10 10 n/cm 2 , although activation was evident. Exposures of CZT to 5 MeV alpha particle at fluences up to 1.5 x 10 10 α/cm 2 produced a near linear decrease in peak position with fluence and increases in FWHM beginning at about 7.5 x 10 9 α/cm 2 . CT detectors show resolution losses after fluences of 3 x 10 9 p/cm 2 at 33 MeV for chlorine-doped detectors. Indium doped material may be more resistant. Neutron exposures (8 MeV) caused resolution losses after fluences of 2 x 10 10 n/cm 2 . Mercuric iodide has been studied with intermediate energy protons (10 to 33 MeV) at fluences up to 10 12 p/cm 2 and with 1.5 GeV protons at fluences up to 1.2 x 10 8 p/cm 2 . Neutron exposures at 8 MeV have been reported at fluences up to 10 15 n/cm 2 . No radiation damage was reported under these irradiation conditions

GIF++: A new CERN Irradiation Facility to test large-area particle detectors for the High-Luminosity LHC program

CERN Document Server

Guida, Roberto

2016-01-01

The high-luminosity LHC (HL-LHC) upgrade is setting a new challenge for particle detector technologies. The increase in luminosity will produce a higher particle background with respect to present conditions. To study performance and stability of detectors at LHC and future HL-LHC upgrades, a new dedicated facility has been built at CERN: the new Gamma Irradiation Facility (GIF++). The GIF++ is a unique place where high energy charged particle beams (mainly muons) are combined with gammas from a 14 TBq 137Cesium source which simulates the background radiation expected at the LHC experiments. Several centralized services and infrastructures are made available to the LHC detector community to facilitate the different R&D; programs.

The Daya Bay antineutrino detector filling system and liquid mass measurement

Science.gov (United States)

Band, H. R.; Cherwinka, J. J.; Draeger, E.; Heeger, K. M.; Hinrichs, P.; Lewis, C. A.; Mattison, H.; McFarlane, M. C.; Webber, D. M.; Wenman, D.; Wang, W.; Wise, T.; Xiao, Q.

2013-09-01

The Daya Bay Reactor Neutrino Experiment has measured the neutrino mixing angle θ13 to world-leading precision. The experiment uses eight antineutrino detectors filled with 20-tons of gadolinium-doped liquid scintillator to detect antineutrinos emitted from the Daya Bay nuclear power plant through the inverse beta decay reaction. The precision measurement of sin22θ13 relies on the relative antineutrino interaction rates between detectors at near (400 m) and far (roughly 1.8 km) distances from the nuclear reactors. The measured interaction rate in each detector is directly proportional to the number of protons in the liquid scintillator target. A precision detector filling system was developed to simultaneously fill the three liquid zones of the antineutrino detectors and measure the relative target mass between detectors to < 0.02%. This paper describes the design, operation, and performance of the system and the resulting precision measurement of the detectors' target liquid masses.

Measurement of indoor radon concentration by CR-39 track detector

International Nuclear Information System (INIS)

Yamamoto, Masayoshi; Yoneda, Shigeru; Nakanishi, Takashi.

1990-01-01

A convenient and cheap method for measuring indoor radon ( 222 Rn) concentration with a CR-39 track detector is described. The detector consisted of two sheets of CR-39 enclosed separately in two plastic pots : one covered by a filter (cup method) and another no covering (bare method). The bare method was used here to supplement the cup method. To compare with the result of the CR-39 detector, alpha-ray spectrometry was carried out with a Si(Au) detector in a controlled radon exposure chamber. Indoor radon concentration measured in 133 houses in several districts of Ishikawa Prefecture have been found to range from 6 Bq/m 3 to as high as 113 Bq/m 3 with a median value of 24 Bq/m 3 . The problems to measure indoor radon concentration using the CR-39 detector are also discussed with emphasis on the position of setting the detector in the room and the possible thoron contribution to the detector. (author)

Temperature effects on radiation damage in plastic detectors

International Nuclear Information System (INIS)

Mendoza A, D.

1996-01-01

The objective of present work was to study the temperature effect on radiation damage registration in the structure of a Solid State Nuclear Track Detector of the type CR-39. In order to study the radiation damage as a function of irradiation temperature, sheets of CR-39 detectors were irradiated with electron beams, simulating the interaction of positive ions. CR-39 detectors were maintained at a constant temperature from room temperature up to 373 K during irradiation. Two techniques were used from analyzing changes in the detector structure: Electronic Paramagnetic Resonance (EPR) and Infrared Spectroscopy (IR). It was found by EPR analysis that the amount of free radicals decrease as irradiation temperature increases. The IR spectrums show yield of new functional group identified as an hydroxyl group (OH). A proposed model of interaction of radiation with CR-39 detectors is discussed. (Author)

Diamond detector technology: status and perspectives

CERN Document Server

Kagan, Harris; Artuso, M; Bachmair, F; Bäni, L; Bartosik, M; Beacham, J; Beck, H P; Bellini,, V; Belyaev, V; Bentele, B; Berdermann, E; Bergonzo, P; Bes, A; Brom, J-M; Bruzzi, M; Cerv, M; Chiodini, G; Chren, D; Cindro, V; Claus, G; Collot, J; Cumalat, J; Dabrowski, A; D'Alessandro, R; De Boer, W; Dehning, B; Dorfer, C; Dunser, M; Eremin, V; Eusebi, R; Forcolin, G; Forneris, J; Frais-Kölbl, H; Gan, K K; Gastal, M; Giroletti, C; Goffe, M; Goldstein, J; Golubev, A; Gorišek, A; Grigoriev, E; Grosse-Knetter, J; Grummer, A; Gui, B; Guthoff, M; Haughton, I; Hiti, B; Hits, D; Hoeferkamp, M; Hofmann, T; Hosslet, J; Hostachy, J-Y; Hügging, F; Hutton, C; Jansen, H; Janssen, J; Kanxheri, K; Kasieczka, G; Kass, R; Kassel, F; Kis, M; Kramberger, G; Kuleshov, S; Lacoste, A; Lagomarsino, S; Lo Giudice, A; Lukosi, E; Maazouzi, C; Mandic, I; Mathieu, C; Mcfadden, N; Menichelli, M; Mikuž, M; Morozzi, A; Moss, J; Mountain, R; Murphy, S; Muškinja, M; Oh, A; Oliviero, P; Passeri, D; Pernegger, H; Perrino, R; Picollo, F; Pomorski, M; Potenza, R; Quadt, A; Re, A; Reichmann, M; Riley, G; Roe, S; Sanz, D; Scaringella, M; Schaefer, D; Schmidt, C J; Schnetzer, S; Schreiner, T; Sciortino, S; Scorzoni, A; Seidel, S; Servoli, L; Sopko, B; Sopko, V; Spagnolo, S; Spanier, S; Stenson, K; Stone, R; Sutera, C; Taylor, Aaron; Traeger, M; Tromson, D; Trischuk, W; Tuve, C; Uplegger, L; Velthuis, J; Venturi, N; Vittone, E; Wagner, Stephen; Wallny, R; Wang, J C; Weingarten, J; Weiss, C; Wengler, T; Wermes, N; Yamouni, M; Zavrtanik, M

2017-01-01

The status of material development of poly-crystalline chemical vapor deposition (CVD) diamond is presented. We also present beam test results on the independence of signal size on incident par-ticle rate in charged particle detectors based on un-irradiated and irradiated poly-crystalline CVD diamond over a range of particle fluxes from 2 kHz/cm2 to 10 MHz/cm2. The pulse height of the sensors was measured with readout electronics with a peaking time of 6 ns. In addition the first beam test results from 3D detectors made with poly-crystalline CVD diamond are presented. Finally the first analysis of LHC data from the ATLAS Diamond Beam Monitor (DBM) which is based on pixelated poly-crystalline CVD diamond sensors bump-bonded to pixel readout elec-tronics is shown.

Nuclear radiation detectors using high resistivity neutron transmutation doped silicon

International Nuclear Information System (INIS)

Gessner, T.; Irmer, K.

1983-01-01

A method for the production of semiconductor detectors based on high resistivity n-type silicon is described. The n-type silicon is produced by neutron irradiation of p-type silicon. The detectors are produced by planar technique. They are suitable for the spectrometry of alpha particles and for the pulse count measurement of beta particles at room temperature. (author)

Uncertainty Quantification of Fork Detector Measurements from Spent Fuel Loading Campaigns

International Nuclear Information System (INIS)

Vaccaro, S.; De Baere, P.; Schwalbach, P.; Gauld, I.; Hu, J.

2015-01-01

With increasing activities at the end of the fuel cycle, the requirements for the verification of spent nuclear fuel for safeguards purposes are continuously growing. In the European Union we are experiencing a dramatic increase in the number of cask loadings for interim dry storage. This is caused by the progressive shut-down of reactors, related to facility ageing but also due to politically motivated phase-out of nuclear power. On the other hand there are advanced plans for the construction of encapsulation plants and geological repositories. The cask loading or the encapsulation process will provide the last occasion to verify the spent fuel assemblies. In this context, Euratom and the US DOE have carried out a critical review of the widely used Fork measurements method of irradiated assemblies. The Nuclear Safeguards directorates of the European Commission's Directorate General for Energy and Oak Ridge National Laboratory have collaborated to improve the Fork data evaluation process and simplify its use for inspection applications. Within the Commission's standard data evaluation package CRISP, we included a SCALE/ORIGEN-based irradiation and depletion simulation of the measured assembly and modelled the fork transfer function to calculate expected count rates based on operator's declarations. The complete acquisition and evaluation process has been automated to compare expected (calculated) with measured count rates. This approach allows a physics-based improvement of the data review and evaluation process. At the same time the new method provides the means for better measurement uncertainty quantification. The present paper will address the implications of the combined approach involving measured and simulated data to the quantification of measurement uncertainty and the consequences of these uncertainties in the possible use of the Fork detector as a partial defect detection method. (author)

Electroweak measurements with the ATLAS detector

CERN Document Server

Krasnopevtsev, Dimitriy; The ATLAS collaboration

2015-01-01

Electroweak measurements with the ATLAS detector -First Run 2 measurements of electroweak processes -Run 1 measurements of SM parameters, i.e. W mass and weak mixing angle -Recent Run 1 measurements of di- and multi-boson production cross-sections as well as vector boson fusion and scattering processes at 8 TeV -Recent Run 1 measurements of exclusive di-lepton and WW production

Design criteria for a hemispherical detector for LET measurements

International Nuclear Information System (INIS)

Schell, M.C.; DeLuca, P.M. Jr.; Pearson, D.W.; Attix, F.H.

1980-01-01

A detector for the direct measurement of the Linear Energy Transfer (LET) in cylindrical geometry was developed by Brandan and DeLuca. The detector successfully measured the LET of protons and a fraction of the heavy charged particles generated in cylindrical A150 plastic and graphite walls by 14.8 MeV neutrons. In this report, we present design tests for the hemispherical LET detector which will measure the LET of charged particles in spherical geometry and allow comparison with calculated LET spectra. The hemispherical LET detector will also provide a data base for radiobiological predictions with the Track Structure Model by Katz. A comparison of predictions of radiobiological effects by the Theory of Dual Radiation Action and the Track Structure Model by Edwards and the authors indicate that the Track Structure Model predicts cell survival as a function of dose more accurately and hence an additional motivation for the present construction of the hemispherical LET detector

Cryogenic Tracking Detectors

CERN Multimedia

Luukka, P R; Tuominen, E M; Mikuz, M

2002-01-01

The recent advances in Si and diamond detector technology give hope of a simple solution to the radiation hardness problem for vertex trackers at the LHC. In particular, we have recently demonstrated that operating a heavily irradiated Si detector at liquid nitrogen (LN$_2$) temperature results in significant recovery of Charge Collection Efficiency (CCE). Among other potential benefits of operation at cryogenic temperatures are the use of large low-resistivity wafers, simple processing, higher and faster electrical signal because of higher mobility and drift velocity of carriers, and lower noise of the readout circuit. A substantial reduction in sensor cost could result The first goal of the approved extension of the RD39 program is to demonstrate that irradiation at low temperature in situ during operation does not affect the results obtained so far by cooling detectors which were irradiated at room temperature. In particular we shall concentrate on processes and materials that could significantly reduce th...

Diamond detectors for high energy physics experiments

Science.gov (United States)

Bäni, L.; Alexopoulos, A.; Artuso, M.; Bachmair, F.; Bartosik, M.; Beacham, J.; Beck, H.; Bellini, V.; Belyaev, V.; Bentele, B.; Berdermann, E.; Bergonzo, P.; Bes, A.; Brom, J.-M.; Bruzzi, M.; Cerv, M.; Chiodini, G.; Chren, D.; Cindro, V.; Claus, G.; Collot, J.; Cumalat, J.; Dabrowski, A.; D'Alessandro, R.; Dauvergne, D.; de Boer, W.; Dorfer, C.; Dünser, M.; Eremin, V.; Eusebi, R.; Forcolin, G.; Forneris, J.; Frais-Kölbl, H.; Gallin-Martel, L.; Gallin-Martel, M. L.; Gan, K. K.; Gastal, M.; Giroletti, C.; Goffe, M.; Goldstein, J.; Golubev, A.; Gorišek, A.; Grigoriev, E.; Grosse-Knetter, J.; Grummer, A.; Gui, B.; Guthoff, M.; Haughton, I.; Hiti, B.; Hits, D.; Hoeferkamp, M.; Hofmann, T.; Hosslet, J.; Hostachy, J.-Y.; Hügging, F.; Hutton, C.; Jansen, H.; Janssen, J.; Kagan, H.; Kanxheri, K.; Kasieczka, G.; Kass, R.; Kassel, F.; Kis, M.; Konovalov, V.; Kramberger, G.; Kuleshov, S.; Lacoste, A.; Lagomarsino, S.; Lo Giudice, A.; Lukosi, E.; Maazouzi, C.; Mandic, I.; Mathieu, C.; Menichelli, M.; Mikuž, M.; Morozzi, A.; Moss, J.; Mountain, R.; Murphy, S.; Muškinja, M.; Oh, A.; Oliviero, P.; Passeri, D.; Pernegger, H.; Perrino, R.; Picollo, F.; Pomorski, M.; Potenza, R.; Quadt, A.; Re, A.; Reichmann, M.; Riley, G.; Roe, S.; Sanz, D.; Scaringella, M.; Schaefer, D.; Schmidt, C. J.; Schnetzer, S.; Sciortino, S.; Scorzoni, A.; Seidel, S.; Servoli, L.; Smith, S.; Sopko, B.; Sopko, V.; Spagnolo, S.; Spanier, S.; Stenson, K.; Stone, R.; Sutera, C.; Tannenwald, B.; Taylor, A.; Traeger, M.; Tromson, D.; Trischuk, W.; Tuve, C.; Uplegger, L.; Velthuis, J.; Venturi, N.; Vittone, E.; Wagner, S.; Wallny, R.; Wang, J. C.; Weingarten, J.; Weiss, C.; Wengler, T.; Wermes, N.; Yamouni, M.; Zavrtanik, M.

2018-01-01

Beam test results of the radiation tolerance study of chemical vapour deposition (CVD) diamond against different particle species and energies is presented. We also present beam test results on the independence of signal size on incident particle rate in charged particle detectors based on un-irradiated and irradiated poly-crystalline CVD diamond over a range of particle fluxes from 2 kHz/cm2 to 10 MHz/cm2. The pulse height of the sensors was measured with readout electronics with a peaking time of 6 ns. In addition functionality of poly-crystalline CVD diamond 3D devices was demonstrated in beam tests and 3D diamond detectors are shown to be a promising technology for applications in future high luminosity experiments.

Operation of Silicon, Diamond and liquid Helium Detectors in the range of Room Temperature to 1.9 K and after an Irradiation Dose of several Mega Gray

CERN Document Server

Kurfuerst, C; Dehning, B; Eisel, T; Sapinski, M; Eremin, V

2013-01-01

At the triplet magnets, close to the interaction regions of the Large Hadron Collider (LHC), the current Beam Loss Monitoring (BLM) system is sensitive to the debris from the collision points. For future beams, with higher energy and intensity the expected increase in luminosity implicate an increase of the debris from interaction products covering the quench-provoking beam losses from the primary proton beams. The investigated option is to locate the detectors as close as possible to the superconducting coil, where the signal ratio of both is optimal. Therefore the detectors have to be located inside the cold mass of the superconducting magnets in superfluid helium at 1.9 Kelvin. Past measurements have shown that a liquid helium ionisation chamber, diamond and silicon detectors are promising candidates for cryogenic beam loss monitors. The carrier parameter, drift velocity, and the leakage current changes will be shown as a function of temperature. New high irradiation test beam measurements at room temperat...

Combined Bulk and Surface Radiation Damage Effects at Very High Fluences in Silicon Detectors: Measurements and TCAD Simulations

CERN Document Server

Moscatelli, F; Morozzi, A; Mendicino, R; Dalla Betta, G F; Bilei, G M

2016-01-01

In this work we propose a new combined TCAD radiation damage modelling scheme, featuring both bulk and surface radiation damage effects, for the analysis of silicon detectors aimed at the High Luminosity LHC. In particular, a surface damage model has been developed by introducing the relevant parameters (NOX, NIT) extracted from experimental measurements carried out on p-type substrate test structures after gamma irradiations at doses in the range 10-500 Mrad(Si). An extended bulk model, by considering impact ionization and deep-level cross-sections variation, was included as well. The model has been validated through the comparison of the simulation findings with experimental measurements carried out at very high fluences (2×1016 1 MeV equivalent n/cm2) thus fostering the application of this TCAD approach for the design and optimization of the new generation of silicon detectors to be used in future HEP experiments.

Depth sensitivity of Lexan polycarbonate detector

CERN Document Server

Awad, E M

1999-01-01

The dependence of the registration sensitivity of Lexan polycarbonate with depth inside the detector was studied. Samples of Lexan from General Electric were irradiated to two long range ions. These were Ni and Au ions with a projectile energy of 0.3 and 1 GeV/n. Two independent techniques, the track-diameter technique (TDT) and the track profile technique (TPT), were used. The registration sensitivity was measured at depths of 7, 10, 15, 18, 20, 28, 35 and 40 mu m inside the detector. The results of the two techniques show that the detector sensitivity decreases gradually with the depth inside the detector. It reaches 20 % less compared to sensitivity at the surface after 40 mu m have been removed.

Performance of n-in-p pixel detectors irradiated at fluences up to $5x10^{15} n_{eq}/cm^{2}$ for the future ATLAS upgrades

CERN Document Server

INSPIRE-00219560; La Rosa, A.; Nisius, R.; Pernegger, H.; Richter, R.H.; Weigell, P.

We present the results of the characterization of novel n-in-p planar pixel detectors, designed for the future upgrades of the ATLAS pixel system. N-in-p silicon devices are a promising candidate to replace the n-in-n sensors thanks to their radiation hardness and cost effectiveness, that allow for enlarging the area instrumented with pixel detectors. The n-in-p modules presented here are composed of pixel sensors produced by CiS connected by bump-bonding to the ATLAS readout chip FE-I3. The characterization of these devices has been performed with the ATLAS pixel read-out systems, TurboDAQ and USBPIX, before and after irradiation with 25 MeV protons and neutrons up to a fluence of 5x10**15 neq /cm2. The charge collection measurements carried out with radioactive sources have proven the feasibility of employing this kind of detectors up to these particle fluences. The collected charge has been measured to be for any fluence in excess of twice the value of the FE-I3 threshold, tuned to 3200 e. The first result...

Performance studies under high irradiation of resistive bulk-micromegas chambers at the CERN Gamma Irradiation Facility

CERN Document Server

Sidiropoulou, Ourania; Bortfeldt, J; Farina, E; Iengo, P; Longo, L; Sidiropoulou, O; Wotschack, J

2017-01-01

Radiation studies on several resistive bulk-Micromegas chambers produced at CERN will be viewed in this document. Two resistive bulk-Micromegas chambers have been installed at the CERN Gamma Irradiation Facility (GIF++) exposed to an intense gamma irradiation with the aim of evaluating the detector behaviour under high irradiation and carrying out a long-term age- ing study. The chambers under study have an active area of 10 x 10 cm 2 , a strip pitch of 400 m m , an ampli- fication gap of 128 m m , and a drift gap of 5 mm. The results on the detector performance as a function of the photon flux up to 44 MHz/cm 2 will be shown as well as the ageing properties as function of the integrated charge and the current intensity and its stability with time. In addition, the results of the efficiency measurements before, during, and after the irradiation will also be presented as a function of the amplification voltage at which the chambers are operated.

First charge collection and position-precision data on the medium-resistivity silicon strip detectors before and after neutron irradiation up to 2x1014 n/cm2

International Nuclear Information System (INIS)

Li Zheng; Dezillie, B.; Eremin, V.; Li, C.J.; Verbitskaya, E.

1999-01-01

Test strip detectors of 125 μm, 500 μm, and 1 mm pitches with about 1 cm 2 areas have been made on medium-resistivity silicon wafers (1.3 and 2.7 kΩ cm). Detectors of 500 μm pitch have been tested for charge collection and position precision before and after neutron irradiation (up to 2x10 14 n/cm 2 ) using 820 and 1030 nm laser lights with different beam-spot sizes. It has been found that for a bias of 250 V a strip detector made of 1.3 kΩ cm (300 μm thick) can be fully depleted before and after an irradiation of 2x10 14 n/cm 2 . For a 500 μm pitch strip detector made of 2.7 kΩ cm tested with an 1030 nm laser light with 200 μm spot size, the position reconstruction error is about 14 μm before irradiation, and 17 μm after about 1.7x10 13 n/cm 2 irradiation. We demonstrated in this work that medium resistivity silicon strip detectors can work just as well as the traditional high-resistivity ones, but with higher radiation tolerance. We also tested charge sharing and position reconstruction using a 1030 nm wavelength (300 μm absorption length in Si at RT) laser, which provides a simulation of MIP particles in high-physics experiments in terms of charge collection and position reconstruction

Implantation of total body irradiation in radiotherapy

International Nuclear Information System (INIS)

Habitzreuter, Angela Beatriz

2010-01-01

Before implementing a treatment technique, the characteristics of the beam under irradiation conditions must be well acknowledged and studied. Each one of the parameters used to calculate the dose has to be measured and validated before its utilization in clinical practice. This is particularly necessary when dealing with special techniques. In this work, all necessary parameters and measurements are described for the total body irradiation implementation in facilities designed for conventional treatments that make use of unconventional geometries to generate desired enlarged field sizes. Furthermore, this work presents commissioning data of this modality at Hospital das Clinicas of Sao Paulo using comparison of three detectors types for measurements of entrance dose during total body irradiation treatment. (author)

Irradiance Impact on Pollution by Integrating Nephelometer Measurements

Directory of Open Access Journals (Sweden)

Maria Rita Perrone

2015-12-01

Full Text Available Three-wavelength integrating nephelometer measurements combined with short- (SW and long-wave (LW irradiance measurements were used to investigate the irradiance effects on the daily evolution of the particulate matter (PM at the ground level, and contribute to the characterization of the land–atmosphere interaction in pollution dispersal. The integrating nephelometer measurements have allowed characterizing the daily changes of the PM optical and microphysical properties by the aerosol scattering coefficient (σp and the scattering Ångström coefficient (å. We found that on a daily basis σp reached the minimum values when the irradiance reached the maximum values, since the convective motions, which favor the particle dispersion at the surface, increase with the irradiance. The å value, which is commonly used as qualitative indicator of the dominant particle size, has allowed evaluating the irradiance effects on the mean particle size distribution at the surface and revealed that the irradiance increase favors mainly the dispersion of the ground-level fine particles. Particle size-distribution measurements supported the last comment. Measurements were performed from 4 to 10 May 2015 when the study site was affected by a Saharan dust outbreak, to also evaluate the impact of long-range transported particles on the daily evolution of the ground-level particle’s properties and the SW and LW irradiance.

Concerns about the dynamic responses of in-core flux detectors

Energy Technology Data Exchange (ETDEWEB)

Cuttler, J.M., E-mail: jerrycuttler@rogers.com [Cuttler & Associates Inc., Mississauga, Ontario (Canada); Gill, H.; Scrannage, R.; Paquette, P., E-mail: jerrycuttler@rogers.com [Bruce Power, Tiverton, Ontario (Canada)

2012-07-01

CANDUs are determining the dynamic responses of flux detectors by a method open to question. It ignores relative changes in local flux conditions, which are significant during trips. Calculated prompt fractions (PFs) are widespread. The SIR detector development calculated the PF change with irradiation on a physical basis. Measurements were made over many years. The current results do not agree with the 1996 predictions. Some values are below the safety analysis limit. This has resulted in detector replacement, imposition of CPPF penalties on trip margins, additional safety analyses and other actions. This paper shows that such measurements are not required. (author)

Measurements of Charge Sharing Effects in Pixilated CZT/CdTe Detectors

DEFF Research Database (Denmark)

Kuvvetli, Irfan; Budtz-Jørgensen, Carl

2007-01-01

In this paper, charge sharing and charge loss effects in pixilated CZT/CdTe detectors are investigated by measurements. We measured charge sharing effects function of the inter-pixel gap (with same pixel pitch), the photon energy and the detector bias voltage for a large numbers of CZT and Cd......Te pixel detector samples. The results are used for the development of the large area X-ray and Gamma ray detector for the Atmosphere-Space Interactions Monitor (ASIM) planned for the ISS ESA Columbus module. Charge sharing measurements on detector samples with identical size and pixel geometry...

A detector for use in high energy bremsstrahlung shielding studies

International Nuclear Information System (INIS)

Wilson, O.J.; Thomson, J.E.M.

1983-01-01

The design, development and calibration of a detector based on the principle of the Moxon-Rae detector is discussed. It is ideally suited to the measurement of the energy fluence of photons transmitted through a thick shield which has been irradiated with high energy bremsstrahlung. The detection sensitivity is 10 4 to 10 5 times that of the P2 ion chamber

Radiation damage resistance in mercuric iodide X-ray detectors

Energy Technology Data Exchange (ETDEWEB)

Patt, B E; Dolin, R C; Devore, T M; Markakis, J M [EG and G Energy Measurements, Inc., Goleta, CA (USA); Iwanczyk, J S; Dorri, N [Xsirius, Inc., Marina del Rey, CA (USA); Trombka, J [National Aeronautics and Space Administration, Greenbelt, MD (USA). Goddard Space Flight Center

1990-12-20

Mercuric iodide (HgI{sub 2}) radiation detectors show great potential as ambient-temperature solid-state detectors for X-rays, gamma rays and visible light, with parameters that are competitive with existing technologies. In a previous experiment, HgI{sub 2} detectors irradiated with 10 MeV protons/cm{sup 2} exhibited no damage. The 10 MeV protons represent only the low range of the spectrum of energies that are important. An experiment has been conducted at the Saturne accelerator facility at Saclay, France, to determine the susceptibility of these detectors to radiation damage by high-energy (1.5 GeV) protons. The detectors were irradiated to a fluence of 10{sup 8} protons/cm{sup 2}. This fluence is equivalent to the cosmic radiation expected in a one-year period in space. The resolution of the detectors was measured as a function of the integral dose. No degradation in the response of any of the detectors or spectrometers was seen. It is clear from this data that HgI{sub 2} has extremely high radiation-damage resistance, exceeding that of most other semiconductor materials used for radiation detectors. Based on the results shown to date, HgI{sub 2} detectors are suitable for applications in which they may be exposed to high integral dose levels. (orig.).

Radiation effects on II-VI compound-based detectors

CERN Document Server

Cavallini, A; Dusi, W; Auricchio, N; Chirco, P; Zanarini, M; Siffert, P; Fougeres, P

2002-01-01

The performance of room temperature CdTe and CdZnTe detectors exposed to a radiation source can be strongly altered by the interaction of the ionizing particles and the material. Up to now, few experimental data are available on the response of II-VI compound detectors to different types of radiation sources. We have carried out a thorough investigation on the effects of gamma-rays, neutrons and electron irradiation both on CdTe : Cl and Cd sub 0 sub . sub 9 Zn sub 0 sub . sub 1 Te detectors. We have studied the detector response after radiation exposure by means of dark current measurements and of quantitative spectroscopic analyses at low and medium energies. The deep traps present in the material have been characterized by means of PICTS (photo-induced current transient spectroscopy) analyses, which allow to determine the trap apparent activation energy and capture cross-section. The evolution of the trap parameters with increasing irradiation doses has been monitored for all the different types of radiati...

Effect of neutron irradiation on etching, optical and structural properties of microscopic glass slide used as a solid state nuclear track detector

International Nuclear Information System (INIS)

Singh, Surinder; Kaur Sandhu, Amanpreet; Prasher, Sangeeta; Prakash Pandey, Om

2007-01-01

Microscopic glass slides are soda-lime glasses which are readily available and are easy to manufacture with low production cost. The application of these glasses as nuclear track detector will help us to make use of these glasses as solid-state nuclear track detector. The present paper describes the variation in the etching, optical and structural properties of the soda-lime microscopic glass slides due to neutron irradiation of different fluences. The color transformation and an increase in the optical absorption with neutron irradiation are observed. Both the bulk and track etch rates are found to increase with neutron fluence, thus showing a similar dependence on neutron fluence, but the sensitivity remains almost constant

Screening of irradiated food using ESR measurement of paper

International Nuclear Information System (INIS)

Goto, Michiko; Yamazaki, Masao

2005-01-01

As paper has high content of cellulose, sensibility of ESR measurements of paper should be high. We examined stability of ESR signals in irradiated recycled copying paper, and estimated the possibility to utilize ESR measurement of paper for the detection of irradiated food. Cellulose radicals in paper irradiated at 1kGy and stored at 40degC in water was detected for 20 days. Cellulose radicals in irradiated paper stored at 90degC in water were more stable than that stored in air. ESR measurements of 50mg paper are simple and easy, so ESR measurement of rapping paper or corrugated box is good screening method for the detection of irradiated food. (author)

Self-Powered Neutron and Gamma Detectors for In-Core Measurements

International Nuclear Information System (INIS)

Strindehag, O.

1971-11-01

The performance of various types of self-powered neutron and gamma detectors intended for control and power distribution measurements in water cooled reactors is discussed. The self-powered detectors are compared with other types of in-core detectors and attention is paid to such properties as neutron and gamma sensitivity, high-temperature performance, burn-up rate and time of response. Also treated are the advantages and disadvantages of using gamma detector data for power distribution calculations instead of data from neutron detectors. With regard to neutron-sensitive detectors, results from several long-term experiments with vanadium and cobalt detectors are presented. The results include reliability and stability data for these two detector types and the Co build-up in cobalt detectors. Experimental results which reveal the fast response of cobalt detectors are presented, and the use of cobalt detectors in reactor safety systems is discussed. Experience of the design and installation of complete flux probes, electronic units and data processing systems for power reactors is reported. The investigation of gamma-sensitive detectors includes detectors with emitters of lead, zirconium, magnesium and Inconel. Measured gamma sensitivities from calibrations both in a reactor and in a gamma cell are given, and the signal levels of self-powered neutron and gamma detectors when applied to power reactors are compared

Self-Powered Neutron and Gamma Detectors for In-Core Measurements

Energy Technology Data Exchange (ETDEWEB)

Strindehag, O

1971-11-15

The performance of various types of self-powered neutron and gamma detectors intended for control and power distribution measurements in water cooled reactors is discussed. The self-powered detectors are compared with other types of in-core detectors and attention is paid to such properties as neutron and gamma sensitivity, high-temperature performance, burn-up rate and time of response. Also treated are the advantages and disadvantages of using gamma detector data for power distribution calculations instead of data from neutron detectors. With regard to neutron-sensitive detectors, results from several long-term experiments with vanadium and cobalt detectors are presented. The results include reliability and stability data for these two detector types and the Co build-up in cobalt detectors. Experimental results which reveal the fast response of cobalt detectors are presented, and the use of cobalt detectors in reactor safety systems is discussed. Experience of the design and installation of complete flux probes, electronic units and data processing systems for power reactors is reported. The investigation of gamma-sensitive detectors includes detectors with emitters of lead, zirconium, magnesium and Inconel. Measured gamma sensitivities from calibrations both in a reactor and in a gamma cell are given, and the signal levels of self-powered neutron and gamma detectors when applied to power reactors are compared

Dosimetric characterization of a commercial two-dimensional array detector; Caracterizacao dosimetrica de um detector matricial bidimensional comercial

Energy Technology Data Exchange (ETDEWEB)

Gialluisi, Bruno L.; Santos, Gabriela R. dos; Sales, Camila P. de; Resende, Guilherme R.A.; Habitzreuter, Angela B.; Rodrigues, Laura N., E-mail: brunogialluisi@gmail.com [Universidade de Sao Paulo (HCFMRP/USP), Sao Paulo, SP (Brazil). Hospital das Clinicas. Servico de Radioterapia

2013-04-15

This paper investigates the dosimetric characteristics and performance of an array detector commercially available. The device is the I'mRT MatriXX® which is a two-dimensional detector array used in the verification of complex radiotherapy plans. It consists of 1,020 parallel plate ion chamber arranged in a 32x32 grid. Dose linearity was studied and its response was linear within the range of 5 to 1000 MU (R{sup 2} = 1). Dose rate dependence showed a maximum deviation of 0,62% comparatively with readings to 320 cGy/min. The detector stability was verified through repeated irradiations. Output factors matched well with measurements made with a Farmer chamber with an average deviation of 1,54%. The detector's effective point of measurement was determined and the inverse square law was also verified with a percentage deviation smaller than 3%. The results show that this detector can be used for quality control in IMRT thus reducing the time spent in the dosimetric verification of radiation fields. (author)

Dosimetric characterization of a commercial two-dimensional array detector; Caracterizacao dosimetrica de um detector matricial bidimensional comercial

Energy Technology Data Exchange (ETDEWEB)

Gialluisi, Bruno L.; Santos, Gabriela R. dos; Sales, Camila P. de; Resende, Guilherme R.A.; Habitzreuter, Angela B.; Rodrigues, Laura N., E-mail: brunogialluisi@gmail.com [Universidade de Sao Paulo (HCFMRP/USP), Sao Paulo, SP (Brazil). Hospital das Clinicas. Servico de Radioterapia

2013-04-15

This paper investigates the dosimetric characteristics and performance of an array detector commercially available. The device is the I'mRT MatriXX® which is a two-dimensional detector array used in the verification of complex radiotherapy plans. It consists of 1,020 parallel plate ion chamber arranged in a 32x32 grid. Dose linearity was studied and its response was linear within the range of 5 to 1000 MU (R{sup 2} = 1). Dose rate dependence showed a maximum deviation of 0,62% comparatively with readings to 320 cGy/min. The detector stability was verified through repeated irradiations. Output factors matched well with measurements made with a Farmer chamber with an average deviation of 1,54%. The detector's effective point of measurement was determined and the inverse square law was also verified with a percentage deviation smaller than 3%. The results show that this detector can be used for quality control in IMRT thus reducing the time spent in the dosimetric verification of radiation fields. (author)

Neutron energy response measurement of scintillation detectors

International Nuclear Information System (INIS)

Yang Hongqiong; Peng Taiping; Yang Jianlun; Tang Zhengyuan; Yang Gaozhao; Li Linbo; Hu Mengchun; Wang Zhentong; Zhang Jianhua; Li Zhongbao; Wang Lizong

2004-01-01

Neutron sensitivities of detectors composed of plastic scintillator ST401, ST1422, ST1423 and phyotomultiplier tube in primary energy range of fission neutron are calibrated by direct current. The energy response curve of the detectors is obtained in this experiment. The experimental result has been compared with the theoretical calculation and they are in agreement within measuring uncertainty. (authors)

Facilities for studying radiation damage in nonmetals during irradiation

International Nuclear Information System (INIS)

Levy, P.W.

1984-08-01

Two facilities have been developed for making optical absorption, luminescence and other measurements on a single sample before, during and after irradiation. One facility uses 60 Co gamma rays and the other 0.5 to 3 MeV electrons from an accelerator. Optical relays function as spectrophotometers, luminescenc detectors, etc. All radiation sensitive components are outside of walk-in irradiation chambers; all measurement control and data recording is computerized. Irradiations are made at controlled temperatures between 5K and 900 0 C. The materials studied include glasses, quartz, alkali halides (especially natural rock salt), organic crystals, etc. As determined from color center measurements the damage formation rate in all materials studied at 25 0 C or above is strongly temperature dependent. The defect concentration during irradiation is usually much greater than that measured after irradiation. The fraction of defects annealing after irradiation and the annealing rate usually increases as the irradiation temperature increases. The completed studies demonstrate that, in most cases, the extent of maximum damage and the damage formation and annealing kinetics can be determined only by making measurements during irradiation

Detector on wheel system (flying spot)

International Nuclear Information System (INIS)

Annis, M.

1980-01-01

An arc-shaped x-ray beam penetrates an arcual cross-sectional area of a body and the attentuated transmitted beam irradiates a portion of a circular array of detectors on a rotating disc. The detectors operate to generate signals proportional to the intensity of the incident transmitted radiation. The beam and detectors are moved along the axis of the body during rotation of the disc to irradiate adjacent cross-sectional areas of the body. A computer operated crt receives the detector signals and displays an image of the radiation attentuation characteristics of the scanned arcual areas

Trapping induced Neff and electrical field transformation at different temperatures in neutron irradiated high resistivity silicon detectors

International Nuclear Information System (INIS)

Eremin, V.; Li, Z.; Iljashenko, I.

1994-02-01

The trapping of both non-equilibrium electrons and holes by neutron induced deep levels in high resistivity silicon planar detectors have been observed. In the experiments Transient Current and Charge Techniques, with short laser light pulse excitation have been applied at temperature ranges of 77--300 k. Light pulse illumination of the front (p + ) and back (n + ) contacts of the detectors showed effective trapping and detrapping, especially for electrons. At temperatures lower than 150 k, the detrapping becomes non-efficient, and the additional negative charge of trapped electrons in the space charge region (SCR) of the detectors leads to dramatic transformations of the electric field due to the distortion of the effective space charge concentration N eff . The current and charge pulses transformation data can be explained in terms of extraction of electric field to the central part of the detector from the regions near both contacts. The initial field distribution may be recovered immediately by dropping reverse bias, which injects both electrons and holes into the space charge region. In the paper, the degree of the N eff distortions among various detectors irradiated by different neutron fluences are compared

Neutron flux measurement by mobile detectors

International Nuclear Information System (INIS)

Verchain, M.

1987-01-01

Various incore instrumentation systems and their technological evolution are first reviewed. Then, for 1300 MWe PWR nuclear power plant, temperature and neutron flux measurement are described. Mobile fission chambers, with their large measuring range and accurate location allow a good knowledge of the core. Other incore measures are possible because of flux detector thimble tubes inserted in the reactor core [fr

Noninvasive Quantum Measurement of Arbitrary Operator Order by Engineered Non-Markovian Detectors

Science.gov (United States)

Bülte, Johannes; Bednorz, Adam; Bruder, Christoph; Belzig, Wolfgang

2018-04-01

The development of solid-state quantum technologies requires the understanding of quantum measurements in interacting, nonisolated quantum systems. In general, a permanent coupling of detectors to a quantum system leads to memory effects that have to be taken into account in interpreting the measurement results. We analyze a generic setup of two detectors coupled to a quantum system and derive a compact formula in the weak-measurement limit that interpolates between an instantaneous (text-book type) and almost continuous—detector dynamics-dependent—measurement. A quantum memory effect that we term "system-mediated detector-detector interaction" is crucial to observe noncommuting observables simultaneously. Finally, we propose a mesoscopic double-dot detector setup in which the memory effect is tunable and that can be used to explore the transition to non-Markovian quantum measurements experimentally.

CdTe/CZT under high flux irradiation

International Nuclear Information System (INIS)

Strassburg, Matthias; Schroeter, Christian; Hackenschmied, Peter

2011-01-01

Direct converting quantum counting detectors based on cadmium telluride and cadmium zinc telluride have been investigated with respect to their properties under intense X-ray irradiation. To derive a detailed picture of the performance of such detectors, the influence of the electric field, the detector thickness, the temperature and the intensity of the X-ray irradiation was studied. The results are discussed in terms of the ''polarization'' phenomenon, a reduction of the electric field strength inside the detector due to immobile charge carriers accumulating during irradiation. Furthermore, the impact of Te-inclusions and -precipitates is presented.

High rate behavior and discharge limits in micro-pattern detectors

CERN Document Server

Bressan, A; Pagano, P; Ropelewski, Leszek; Sauli, Fabio; Biagi, S F; Buzulutskov, A F; Gruwé, M; De Lentdecker, G; Mörmann, D; Sharma, A

1999-01-01

We present and discuss a set of systematic measurements, carried out with gaseous proportional micro-pattern detectors, in order to assess their maximum gain when irradiated with high-rate soft X-rays and heavily ionizing alpha particles. The inventory of detectors tested includes: micro-strip micromegas, micro-dot, gas electron multiplier, CAT (compteur à trous), trench (or groove), micro-CAT (or WELL) detectors, as well as systems with two elements of gaseous amplification in cascade. We confirm the general trend of all single-stage detectors to follow Raether's criterion, i.e. a spontaneous transition from avalanche to streamer, followed by a discharge, when the avalanche size reaches a value of a few 10 7 ; a noticeable exception is the micro-dot counter holding more than 10 8. In multiple structures, where the gain under irradiation is increased by at least one order of magnitude; we speculate this to be a consequence of a voltage dependence of Raether's limit, larger for low operating potentials. Our c...

Advances in the project about Pin type silicon radiation detectors; Avances en el proyecto sobre detectores de radiacion de silicio tipo PIN

Energy Technology Data Exchange (ETDEWEB)

Ramirez F, J. [Instituto Nacional de Investigaciones Nucleares, Laboratorio de Detectores de Radiacion, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Cerdeira, A.; Aceves, M.; Diaz, A.; Estrada, M.; Rosales, P.; Cabal, A.E.; Montano L, M.; Leyva, A

1998-07-01

The obtained advances in the collaboration project ININ-CINVESTAV about development of Pin type semiconductor radiation detectors here are presented. It has been characterized the response to different types of radiation made in CINVESTAV and INAOE. Measurements have been realized with different types of sensitive to charge preamplifiers determining the main characteristics which must be executed to be able to be employed with low capacitance detectors. As applications it has been possible to measure the irradiation time in a mammography machine and X-ray energy spectra have been obtained in the order of 14 KeV, with 4 KeV at ambient temperature. The future actions of project have been indicated and the possible applications of these detectors. (Author)

Utilization of plastic detector for pool water radioactivity control of IEA-R1 reactor. Examination of fuel element irradiation behaviour fabricated at IPEN/CNEN-SP

International Nuclear Information System (INIS)

Berretta, J.R.; Mesquita, C.H. de; Madi Filho, T.

1989-01-01

For the examination of fuel element irradiation behavior that were fabricated at IPEN/CNEN/SP Metalurgical Departament, it was provided a detection system for pool water radioactivity measurements. This system uses a plastic scintillator detector produced at IPEN/CNEN-SP Health Physics Department, with dimensions and shape apropriated for such work. The detection system shows a sensibility of 4.125x10 -2 dps/cm 3 and 20% of efficiency for 131 I radiations. (author) [pt

The Siegen automatic measuring system for track detectors: new developments

International Nuclear Information System (INIS)

Rusch, G.; Winkel, E.; Noll, A.; Heinrich, W.

1991-01-01

Starting twelve years ago we have developed completely automatic scanning and measuring systems for nuclear track detectors. The hardware and software of these systems have continuously been improved. They were used in different heavy ion and cosmic ray experiments. In this paper we describe methods for high resolution REL measurements in plastic nuclear track detectors and methods to scan and measure nuclear disintegration stars in AgCl detectors using an automatic measuring technique. The system uses a stepping motor driven microscope stage, a video camera and an image analysis computer based on a MC68020 microprocessor. (author)

Investigation of radiation damage effects in neutron irradiated CCD

International Nuclear Information System (INIS)

Brau, James E.; Igonkina, Olga; Potter, Chris T.; Sinev, Nikolai B.

2005-01-01

A Charge Coupled Devices (CCD)-based vertex detector is a leading option for vertex detection at the future linear collider. A major issue for this application is the radiation hardness of such devices. Tests of radiation hardness of CCDs used in the SLD vertex detector, VXD3, have been reported earlier. The first measurements of 1998 involved a spare VXD3 CCD that was irradiated with neutrons from a radioactive source (Pu-Be), and from a nuclear reactor. In 2003, we had the opportunity to disassemble the VXD3 detector and study the nature of the radiation damage it incurred during 3 years of operation at SLC. In the preparation for this study, additional experiments with the spare VXD3 CCD were performed. These included measurements of trapping times in neutron irradiated CCDs. Results, reported here, will help us better understand the mechanism of radiation damage effects and develop techniques to minimize performance degradation due to radiation damage

Radiation hardness of thin Low Gain Avalanche Detectors

Science.gov (United States)

Kramberger, G.; Carulla, M.; Cavallaro, E.; Cindro, V.; Flores, D.; Galloway, Z.; Grinstein, S.; Hidalgo, S.; Fadeyev, V.; Lange, J.; Mandić, I.; Medin, G.; Merlos, A.; McKinney-Martinez, F.; Mikuž, M.; Quirion, D.; Pellegrini, G.; Petek, M.; Sadrozinski, H. F.-W.; Seiden, A.; Zavrtanik, M.

2018-05-01

Low Gain Avalanche Detectors (LGAD) are based on a n++-p+-p-p++ structure where an appropriate doping of the multiplication layer (p+) leads to high enough electric fields for impact ionization. Gain factors of few tens in charge significantly improve the resolution of timing measurements, particularly for thin detectors, where the timing performance was shown to be limited by Landau fluctuations. The main obstacle for their operation is the decrease of gain with irradiation, attributed to effective acceptor removal in the gain layer. Sets of thin sensors were produced by two different producers on different substrates, with different gain layer doping profiles and thicknesses (45, 50 and 80 μm). Their performance in terms of gain/collected charge and leakage current was compared before and after irradiation with neutrons and pions up to the equivalent fluences of 5 ṡ 1015 cm-2. Transient Current Technique and charge collection measurements with LHC speed electronics were employed to characterize the detectors. The thin LGAD sensors were shown to perform much better than sensors of standard thickness (∼300 μm) and offer larger charge collection with respect to detectors without gain layer for fluences gain prolongs the beneficial performance of LGADs. Pions were found to be more damaging than neutrons at the same equivalent fluence, while no significant difference was found between different producers. At very high fluences and bias voltages the gain appears due to deep acceptors in the bulk, hence also in thin standard detectors.

Studies of frequency dependent C-V characteristics of neutron irradiated p+-n silicon detectors

International Nuclear Information System (INIS)

Li, Zheng; Kraner, H.W.

1990-10-01

Frequency-dependent capacitance-voltage fluence (C-V) characteristics of neutron irradiated high resistivity silicon p + -n detectors have been observed up to a fluence of 8.0 x 10 12 n/cm 2 . It has been found that frequency dependence of the deviation of the C-V characteristic (from its normal V -1/2 dependence), is strongly dependent on the ratio of the defect density and the effective doping density N t /N' d . As the defect density approaches the effective dopant density, or N t /N' d → 1, the junction capacitance eventually assumes the value of the detector geometry capacitance at high frequencies (f ≤ 10 5 Hz), independent of voltage. A two-trap-level model using the concept of quasi-fermi levels has been developed, which predicts both the effects of C-V frequency dependence and dopant compensation observed in this study

Time development and flux dependence of neutron-irradiation induced defects in silicon pad detectors

CERN Document Server

Zontar, D; Kramberger, G; Mikuz, M

1999-01-01

1x1 cm sup 2 silicon pad p sup + -n-n sup + detectors were irradiated with fast neutrons from the TRIGA research reactor in Ljubljana to fluences from 5x10 sup 1 sup 3 to 10 sup 1 sup 4 n/cm sup 2. The observed time development of annealing of the full-depletion voltage (FDV) could be fitted by a constant and two exponentials. The characteristic time of the fast component is 4 h, independent of temperature in the interval 0-15 deg. C. A comparison of MESA and planar pad detectors shows a 20-30% lower FDV for the MESA. A search for a flux dependence of the radiation damage was performed in the range from 2x10 sup 8 to 5x10 sup 1 sup 5 n/cm sup 2 s and no systematic differences were observed.

Measurements of output factors with different detector types and Monte Carlo calculations of stopping-power ratios for degraded electron beams

International Nuclear Information System (INIS)

Bjoerk, Peter; Knoeoes, Tommy; Nilsson, Per

2004-01-01

The aim of the present study was to investigate three different detector types (a parallel-plate ionization chamber, a p-type silicon diode and a diamond detector) with regard to output factor measurements in degraded electron beams, such as those encountered in small-electron-field radiotherapy and intraoperative radiation therapy (IORT). The Monte Carlo method was used to calculate mass collision stopping-power ratios between water and the different detector materials for these complex electron beams (nominal energies of 6, 12 and 20 MeV). The diamond detector was shown to exhibit excellent properties for output factor measurements in degraded beams and was therefore used as a reference. The diode detector was found to be well suited for practical measurements of output factors, although the water-to-silicon stopping-power ratio was shown to vary slightly with treatment set-up and irradiation depth (especially for lower electron energies). Application of ionization-chamber-based dosimetry, according to international dosimetry protocols, will introduce uncertainties smaller than 0.3% into the output factor determination for conventional IORT beams if the variation of the water-to-air stopping-power ratio is not taken into account. The IORT system at our department includes a 0.3 cm thin plastic scatterer inside the therapeutic beam, which furthermore increases the energy degradation of the electrons. By ignoring the change in the water-to-air stopping-power ratio due to this scatterer, the output factor could be underestimated by up to 1.3%. This was verified by the measurements. In small-electron-beam dosimetry, the water-to-air stopping-power ratio variation with field size could mostly be ignored. For fields with flat lateral dose profiles (>3 x 3 cm 2 ), output factors determined with the ionization chamber were found to be in close agreement with the results of the diamond detector. For smaller field sizes the lateral extension of the ionization chamber

Measurements of output factors with different detector types and Monte Carlo calculations of stopping-power ratios for degraded electron beams.

Science.gov (United States)

Björk, Peter; Knöös, Tommy; Nilsson, Per

2004-10-07

The aim of the present study was to investigate three different detector types (a parallel-plate ionization chamber, a p-type silicon diode and a diamond detector) with regard to output factor measurements in degraded electron beams, such as those encountered in small-electron-field radiotherapy and intraoperative radiation therapy (IORT). The Monte Carlo method was used to calculate mass collision stopping-power ratios between water and the different detector materials for these complex electron beams (nominal energies of 6, 12 and 20 MeV). The diamond detector was shown to exhibit excellent properties for output factor measurements in degraded beams and was therefore used as a reference. The diode detector was found to be well suited for practical measurements of output factors, although the water-to-silicon stopping-power ratio was shown to vary slightly with treatment set-up and irradiation depth (especially for lower electron energies). Application of ionization-chamber-based dosimetry, according to international dosimetry protocols, will introduce uncertainties smaller than 0.3% into the output factor determination for conventional IORT beams if the variation of the water-to-air stopping-power ratio is not taken into account. The IORT system at our department includes a 0.3 cm thin plastic scatterer inside the therapeutic beam, which furthermore increases the energy degradation of the electrons. By ignoring the change in the water-to-air stopping-power ratio due to this scatterer, the output factor could be underestimated by up to 1.3%. This was verified by the measurements. In small-electron-beam dosimetry, the water-to-air stopping-power ratio variation with field size could mostly be ignored. For fields with flat lateral dose profiles (>3 x 3 cm2), output factors determined with the ionization chamber were found to be in close agreement with the results of the diamond detector. For smaller field sizes the lateral extension of the ionization chamber hampers

Characterization of proton and neutron irradiated low resistivity p-on-n magnetic Czochralski ministrip sensors and diodes

International Nuclear Information System (INIS)

Pacifico, Nicola; Dolenc Kittelmann, Irena; Fahrer, Manuel; Moll, Michael; Militaru, Otilia

2011-01-01

Transient Current Technique (TCT) and Charge Collection Efficiency (CCE) measurements were performed on low resistivity (280Ωcm) n-bulk, p-readout magnetic Czochralski ministrip sensors and diodes. The detectors were irradiated with neutrons and 24 GeV/c protons up to a total NIEL equivalent fluence of 8×10 15 /cm 2 . The study was addressed to assess the radiation tolerance of the detectors up to fluences expected in the next generations of High Energy Physics experiments. The charge collection efficiency after irradiation was found to be much higher than for standard FZ silicon p-in-n sensors. The underlying physics of this remarkable result was investigated by performing Edge-TCT measurements on one of the neutron irradiated ministrip sensors to extract detailed informations about the field and efficiency profiles of the detector.

Spallation products induced by energetic neutrons in plastic detector material

CERN Document Server

Grabisch, K; Enge, W; Scherzer, R

1977-01-01

Cellulose nitrate plastic detector sheets were irradiated with secondary neutrons of the 22 GeV/c proton beam at the CERN accelerator. He, Li and Be particles which are produced in nuclear interactions of the neutrons with the target elements C, N and O of the plastic detector material are measured. Preliminary angle and range distributions and isotropic abundances of the secondary particles are discussed. (6 refs).

Characterization of gaseous detectors at the CERN Gamma Irradiation Facility: GEM performance in presence of high background radiation

CERN Document Server

AUTHOR|(CDS)2097588

Muon detection is an efficient tool to recognize interesting physics events over the high background rate expected at the Large Hadron Collider (LHC) at CERN. The muon systems of the LHC experiments are based on gaseous ionization detectors. In view of the High-Luminosity LHC (HL-LHC) upgrade program, the increasing of background radiation could affect the gaseous detector performance, especially decreasing the efficiency and shortening the lifetime through ageing processes. The effects of charge multiplication, materials and gas composition on the ageing of gaseous detectors have been studied for decades, but the future upgrade of LHC requires additional studies on this topic. At the CERN Gamma Irradiation Facility (GIF++), a radioactive source of cesium-137 with an activity of 14 TBq is used to reproduce reasonably well the expected background radiation at HL-LHC. A muon beam has been made available to study detector performance. The characterization of the beam trigger will be discussed in the present w...

Calibration and alignment of the CMS silicon tracking detector

International Nuclear Information System (INIS)

Stoye, M.

2007-07-01

The Large Hadron Collider (LHC) will dominate the high energy physics program in the coming decade. The discovery of the standard model Higgs boson and the discovery of super-symmetric particles are within the reach at the energy scale explored by the LHC. However, the high luminosity and the high energy of the colliding protons lead to challenging demands on the detectors. The hostile radiation environment requires irradiation hard detectors, where the innermost subdetectors, consisting of silicon modules, are most affected. This thesis is devoted to the calibration and alignment of the silicon tracking detector. Electron test beam data, taken at DESY, have been used to investigate the performance of detector modules which previously were irradiated with protons up to a dose expected after 10 years of operation. The irradiated sensors turned out to be still better than required. The performance of the inner tracking systems will be dominated by the degree to which the positions of the sensors can be determined. Only a track based alignment procedure can reach the required precision. Such an alignment procedure is a major challenge given that about 50000 geometry constants need to be measured. Making use of the novel χ 2 minimization program Millepede II an alignment strategy has been developed in which all detector components are aligned simultaneously, as many sources of information as possible are used, and all correlations between the position parameters of the detectors are taken into account. Utilizing simulated data, a proof of concept of the alignment strategy is shown. (orig.)

Calibration and alignment of the CMS silicon tracking detector

Energy Technology Data Exchange (ETDEWEB)

Stoye, M.

2007-07-15

The Large Hadron Collider (LHC) will dominate the high energy physics program in the coming decade. The discovery of the standard model Higgs boson and the discovery of super-symmetric particles are within the reach at the energy scale explored by the LHC. However, the high luminosity and the high energy of the colliding protons lead to challenging demands on the detectors. The hostile radiation environment requires irradiation hard detectors, where the innermost subdetectors, consisting of silicon modules, are most affected. This thesis is devoted to the calibration and alignment of the silicon tracking detector. Electron test beam data, taken at DESY, have been used to investigate the performance of detector modules which previously were irradiated with protons up to a dose expected after 10 years of operation. The irradiated sensors turned out to be still better than required. The performance of the inner tracking systems will be dominated by the degree to which the positions of the sensors can be determined. Only a track based alignment procedure can reach the required precision. Such an alignment procedure is a major challenge given that about 50000 geometry constants need to be measured. Making use of the novel {chi}{sup 2} minimization program Millepede II an alignment strategy has been developed in which all detector components are aligned simultaneously, as many sources of information as possible are used, and all correlations between the position parameters of the detectors are taken into account. Utilizing simulated data, a proof of concept of the alignment strategy is shown. (orig.)

Fast neutron detection at near-core location of a research reactor with a SiC detector

Science.gov (United States)

Wang, Lei; Jarrell, Josh; Xue, Sha; Tan, Chuting; Blue, Thomas; Cao, Lei R.

2018-04-01

The measurable charged-particle produced from the fast neutron interactions with the Si and C nucleuses can make a wide bandgap silicon carbide (SiC) sensor intrinsically sensitive to neutrons. The 4H-SiC Schottky detectors have been fabricated and tested at up to 500 °C, presenting only a slightly degraded energy resolution. The response spectrum of the SiC detectors were also obtained by exposing the detectors to external neutron beam irradiation and at a near-core location where gamma-ray field is intense. The fast neutron flux of these two locations are ∼ 4 . 8 × 104cm-2 ṡs-1 and ∼ 2 . 2 × 107cm-2 ṡs-1, respectively. At the external beam location, a Si detector was irradiated side-by-side with SiC detector to disjoin the neutron response from Si atoms. The contribution of gamma ray, neutron scattering, and charged-particles producing reactions in the SiC was discussed. The fast neutron detection efficiencies were determined to be 6 . 43 × 10-4 for the external fast neutron beam irradiation and 6 . 13 × 10-6 for the near-core fast neutron irradiation.

Energy-loss measurement with the ZEUS Central Tracking Detector

International Nuclear Information System (INIS)

Bartsch, D.

2007-05-01

The measurement of the specific energy loss due to ionisation, dE/dx, in a drift chamber is a very important tool for particle identification in final states of reactions between high energetic particles. Such identification requires a well understood dE/dx measurement including a precise knowledge of its uncertainties. Exploiting for the first time the full set of ZEUS data from the HERA operation between 1996 and 2005 twelve detector-related influences affecting the dE/dx measurement of the ZEUS Central Tracking Detector have been identified, separately studied and parameterised. A sophisticated iterative procedure has been developed to correct for these twelve effects, which takes into account the correlations between them. A universal parameterisation of the detector-specific Bethe-Bloch curve valid for all particle species has been extracted. In addition, the various contributions to the measurement uncertainty have been disentangled and determined. This yields the best achievable prediction for the single-track dE/dx resolution. For both the analysis of the measured data and the simulation of detector performance, the detailed understanding of the measurement and resolution of dE/dx gained in this work provides a tool with optimum power for particle identification in a physics studies. (orig.)

Energy-loss measurement with the ZEUS Central Tracking Detector

Energy Technology Data Exchange (ETDEWEB)

Bartsch, D.

2007-05-15

The measurement of the specific energy loss due to ionisation, dE/dx, in a drift chamber is a very important tool for particle identification in final states of reactions between high energetic particles. Such identification requires a well understood dE/dx measurement including a precise knowledge of its uncertainties. Exploiting for the first time the full set of ZEUS data from the HERA operation between 1996 and 2005 twelve detector-related influences affecting the dE/dx measurement of the ZEUS Central Tracking Detector have been identified, separately studied and parameterised. A sophisticated iterative procedure has been developed to correct for these twelve effects, which takes into account the correlations between them. A universal parameterisation of the detector-specific Bethe-Bloch curve valid for all particle species has been extracted. In addition, the various contributions to the measurement uncertainty have been disentangled and determined. This yields the best achievable prediction for the single-track dE/dx resolution. For both the analysis of the measured data and the simulation of detector performance, the detailed understanding of the measurement and resolution of dE/dx gained in this work provides a tool with optimum power for particle identification in a physics studies. (orig.)

Radiation damage in proton-irradiated epitaxial silicon detectors

Energy Technology Data Exchange (ETDEWEB)

Lange, Joern

2009-07-15

In this work radiation hardness of 75 {mu}m, 100 {mu}m and 150 {mu}m thick epitaxial silicon pad diodes of both standard and oxygenated material was investigated. Damage after 24 GeV/c proton irradiation in a 1MeV neutron equivalent fluence range between 10{sup 14} cm{sup -2} and 10{sup 16} cm{sup -2} was studied and isothermal annealing experiments at 80 C were carried out. Standard CV/IV measurements could be performed up to 4 x 10{sup 15} cm{sup -2}. The volume-normalised reverse current was found to increase linearly with fluence with a slope independent of the thickness and impurity concentration. However, due to large fluctuations the fluences had to be renormalised using the current-related damage parameter. Concerning the depletion voltage, nearly all materials remained at a moderate level up to 4 x 10{sup 15} cm{sup -2}. During short-term annealing acceptors annealed out, whereas others were introduced during the long-term annealing. The stable damage was characterised by donor removal at low fluences and fluence-proportional predominant donor introduction for highly irradiated diodes, depending on the oxygen level. No type inversion was observed. Time-resolved measurements with a new 670 nm laser-TCT setup made the determination of the trapping time constant with the charge correction method possible. The results agreed with expectations and showed a linear increase of trapping probability with fluence. The electric field exhibited a double peak structure in highly irradiated diodes. Charge collection efficiency measurements with {alpha}-particles were independent of oxygen concentration, but showed an improved efficiency for thinner diodes. A comparison to simulation revealed systematic discrepancies. A non-constant trapping time parameter was proposed as possible solution. (orig.)

Radiation damage in proton-irradiated epitaxial silicon detectors

International Nuclear Information System (INIS)

Lange, Joern

2009-07-01

In this work radiation hardness of 75 μm, 100 μm and 150 μm thick epitaxial silicon pad diodes of both standard and oxygenated material was investigated. Damage after 24 GeV/c proton irradiation in a 1MeV neutron equivalent fluence range between 10 14 cm -2 and 10 16 cm -2 was studied and isothermal annealing experiments at 80 C were carried out. Standard CV/IV measurements could be performed up to 4 x 10 15 cm -2 . The volume-normalised reverse current was found to increase linearly with fluence with a slope independent of the thickness and impurity concentration. However, due to large fluctuations the fluences had to be renormalised using the current-related damage parameter. Concerning the depletion voltage, nearly all materials remained at a moderate level up to 4 x 10 15 cm -2 . During short-term annealing acceptors annealed out, whereas others were introduced during the long-term annealing. The stable damage was characterised by donor removal at low fluences and fluence-proportional predominant donor introduction for highly irradiated diodes, depending on the oxygen level. No type inversion was observed. Time-resolved measurements with a new 670 nm laser-TCT setup made the determination of the trapping time constant with the charge correction method possible. The results agreed with expectations and showed a linear increase of trapping probability with fluence. The electric field exhibited a double peak structure in highly irradiated diodes. Charge collection efficiency measurements with α-particles were independent of oxygen concentration, but showed an improved efficiency for thinner diodes. A comparison to simulation revealed systematic discrepancies. A non-constant trapping time parameter was proposed as possible solution. (orig.)

Irradiation effects in fused quartz 'Suprasil' as a detector of fission fragments under high flux of reactor neutrons

International Nuclear Information System (INIS)

Moraes, O.M.G. de.

1984-01-01

A systematic study about the registration characteristics of synthetic fused quartz 'Suprasil I' use as a detector of fission fragments under high flux of reactor neutrons and the effects of irradiation on it was performed. Fission fragments of 252 Cf, gamma radiation doses of of 60 Co up to 150 MGy, and integrated neutrons fluxes up to 10 20 n/cm 2 were used. A model to explain the effects on track registration and development characteristics of 'Suprasil I' irradiated on reactors were proposed, based on the obtained results for efficiency an for annealing. (C.G.C.) [pt

Detector Control System and Efficiency Performance for CMS RPC at GIF++

CERN Document Server

Gul, Muhammad; Cimmino, A; Crucy, S; Fagot, A; Rios, A A O; Tytgat, M; Zaganidis, N; Aly, S; Assran, Y; Radi, A; Sayed, A; Singh, G; Abbrescia, M; Iaselli, G; Maggi, M; Pugliese, G; Verwilligen, P; Doninck, W V; Colafranceschi, S; Sharma, A; Benussi, L; Bianco, S; Piccolo, D; Primavera, F; Bhatnagar, V; Kumari, R; Mehta, A; Singh, J; Ahmad, A; Asghar, M I; Muhammad, S; Awan, I A; Hoorani, H R; Ahmed, W; Shahzad, H; Shah, M A; Cho, S W; Choi, S Y; Hong, B; Kang, M H; Lee, K S; Lim, J H; Park, S K; Kim, M; Goutzvitz, M; Grenier, G; Lagarde, F; Estrada, C U; Pedraza, I; Severiano, C B; Carrillo Moreno, S; Vazquez Valencia, F; Pant, L M; Buontempo, S; Cavallo, N; Esposito, M; Fabozzi, F; Lanza, G; Lista, L; Meola, S; Merola, M; Orso, I; Paolucci, P; Thyssen, F; Braghieri, A; Magnani, A; Montagna, P; Riccardi, C; Salvini, P; Vai, I; Vitulo, P; Ban, Y; Qian, S J; Choi, M; Choi, Y; Goh, J; Kim, D; Aleksandrov, A; Hadjiiska, R; Iaydjiev, P; Rodozov, M; Stoykova, S; Sultanov, G; Vutova, M; Dimitrov, A; Litov, L; Pavlov, B; Petkov, P; Lomidze, D; Bagaturia, I; Avila, C; Cabrera, A; Sanabria, J C; Crotty, I; Vaitkus, J

2016-01-01

In the framework of the High Luminosity LHC upgrade program, the CMS muon group built several different RPC prototypes that are now under test at the new CERN Gamma Irradiation Facility (GIF++). A dedicated Detector Control System has been developed using the WinCC-OA tool to control and monitor these prototype detectors and to store the measured parameters data.

A scintillation detector for measuring inert gas beta rays

International Nuclear Information System (INIS)

Shi Hengchang; Yu Yunchang

1989-10-01

The inert gas beta ray scintillation detector, which is made of organic high polymers as the base and coated with compact fluorescence materials, is a lower energy scintillation detector. It can be used in the nuclear power plant and radioactive fields as a lower energy monitor to detect inert gas beta rays. Under the conditions of time constant 10 minutes, confidence level is 99.7% (3σ), the intensity of gamma rays 2.6 x 10 -7 C/kg ( 60 Co), and the minimum detectable concentration (MDC) of this detector for 133 Xe 1.2 Bq/L. The measuring range for 133 Xe is 11.1 ∼ 3.7 x 10 4 Bq/L. After a special measure is taken, the device is able to withstand 3 x 10 5 Pa gauge pressure. In the loss-of-cooolant-accident, it can prevent the radioactive gas of the detector from leaking. This detector is easier to be manufactured and decontaminated

CVD Diamond Sensors In Detectors For High Energy Physics

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00334150; Trischuk, William

At the end of the next decade an upgrade of the Large Hadron Collider (LHC) to High Luminosity LHC (HL-LHC) is planned which requires the development of new radiation tolerant sensor technology. Diamond is an interesting material for use as a particle detector in high radiation environments. The large band gap ($5.47\\,\\text{eV}$) and the large displacement energy suggest that diamond is a radiation tolerant detector material. In this Thesis the capability of Chemical Vapor Deposition (CVD) diamond as such a sensor technology is investigated. The radiation damage constant for $800\\,\\text{MeV}$ protons is measured using single crystalline CVD (scCVD) and polycrystalline CVD (pCVD) diamonds irradiated to particle fluences up to $12 \\times 10^{15}\\,\\text{p/cm}^2$. In addition the signal response of a pCVD diamond detector after an irradiation to $12 \\times 10^{15}\\,\\text{p/cm}^2$ is investigated to determine if such a detector can be operated efficiently in the expected HL-LHC environment. By using electrodes em...

Vanadium Beta Emission Detectors for Reactor In-Core Neutron Monitoring

Energy Technology Data Exchange (ETDEWEB)

Andersson, I Oe; Soederlund, B

1969-06-15

In-core flux measurements are becoming increasingly important in both power reactors and test reactors. In particular power distribution measurements in large power reactors have to be performed with a great number of neutron detectors capable of withstanding high integrated flux values. This report presents a summary of the development and application of a new type of nuclear radiation sensor, a beta emission detector, for measurements at high neutron flux levels. The work has been carried out at the Section for Instrumentation and has been the basis for a type of neutron detector employed in the Marviken in-core system as well as for other types. The report describes the design and principle of operation, experiments and tests. Also included are the results and comments from a long-term irradiation of some detectors in the Halden reactor.

Dose measurement method suitable for management of food irradiation

International Nuclear Information System (INIS)

Tanaka, Ryuichi

1990-01-01

The report describes major features of dose measurement performed for the management of food irradiation processes, and dose measuring methods suitable for this purpose, and outlines some activities for establishing international standards for dose measurement. Traceability studies made recently are also reviewed. Compared with the sterilization of medical materials, food irradiation is different in some major points from a viewpoint of dose measurement: foods can undergo significant changes in bulk density, depending on its properties, during irradiation, and the variation in the uniformity of bulk density can be large within an irradiation unit and among different units. An accurate dosimeter and well-established traceability are essential for food irradiation control, and basically a dosimeter should be high in reproducibility and stable in dose response, and should be easy to readjust for eliminating systematic errors. A new type of dosimeter was developed recently, in which ESR is used to measure the free radicals generated by radiations in crystals of alanine, an amino acid. Standardization of large dose measurement procedures has been carried out by committee E10 set up under ASTM. (N.K.)

Studies on Flat Sandwich-type Self-Powered Detectors for Flux Measurements in ITER Test Blanket Modules

Science.gov (United States)

Raj, Prasoon; Angelone, Maurizio; Döring, Toralf; Eberhardt, Klaus; Fischer, Ulrich; Klix, Axel; Schwengner, Ronald

2018-01-01

Neutron and gamma flux measurements in designated positions in the test blanket modules (TBM) of ITER will be important tasks during ITER's campaigns. As part of the ongoing task on development of nuclear instrumentation for application in European ITER TBMs, experimental investigations on self-powered detectors (SPD) are undertaken. This paper reports the findings of neutron and photon irradiation tests performed with a test SPD in flat sandwich-like geometry. Whereas both neutrons and gammas can be detected with appropriate optimization of geometries, materials and sizes of the components, the present sandwich-like design is more sensitive to gammas than 14 MeV neutrons. Range of SPD current signals achievable under TBM conditions are predicted based on the SPD sensitivities measured in this work.

The origin of double peak electric field distribution in heavily irradiated silicon detectors

CERN Document Server

Eremin, V; Li, Z

2002-01-01

The first observation of double peak (DP) electric field distribution in heavily neutron irradiated (>10 sup 1 sup 4 n/cm sup 2) semiconductor detectors has been published about 6 yr ago. However, this effect was not quantitatively analyzed up to now. The explanation of the DP electric field distribution presented in this paper is based on the properties of radiation induced deep levels in silicon, which act as deep traps, and on the distribution of the thermally generated free carrier concentration in the detector bulk. In the frame of this model, the earlier published considerations on the so-called 'double junction (DJ) effect' are discussed as well. The comparison of the calculated electric field profiles at different temperatures with the experimental ones allows one to determine a set of deep levels. This set of deep levels, and their charge filling status are essential to the value and the distribution of space charge in the space charge region in the range of 305-240 K, which is actual temperature ran...

First charge collection and position-precision data on the medium-resistivity silicon strip detectors before and after neutron irradiation up to 2x10 sup 1 sup 4 n/cm sup 2

CERN Document Server

Li Zheng; Eremin, V; Li, C J; Verbitskaya, E

1999-01-01

Test strip detectors of 125 mu m, 500 mu m, and 1 mm pitches with about 1 cm sup 2 areas have been made on medium-resistivity silicon wafers (1.3 and 2.7 k OMEGA cm). Detectors of 500 mu m pitch have been tested for charge collection and position precision before and after neutron irradiation (up to 2x10 sup 1 sup 4 n/cm sup 2) using 820 and 1030 nm laser lights with different beam-spot sizes. It has been found that for a bias of 250 V a strip detector made of 1.3 k OMEGA cm (300 mu m thick) can be fully depleted before and after an irradiation of 2x10 sup 1 sup 4 n/cm sup 2. For a 500 mu m pitch strip detector made of 2.7 k OMEGA cm tested with an 1030 nm laser light with 200 mu m spot size, the position reconstruction error is about 14 mu m before irradiation, and 17 mu m after about 1.7x10 sup 1 sup 3 n/cm sup 2 irradiation. We demonstrated in this work that medium resistivity silicon strip detectors can work just as well as the traditional high-resistivity ones, but with higher radiation tolerance. We als...

MARTA: A high-energy cosmic-ray detector concept with high-accuracy muon measurement

Energy Technology Data Exchange (ETDEWEB)

Abreu, P.; et al.

2017-12-20

A new concept for the direct measurement of muons in air showers is presented. The concept is based on resistive plate chambers (RPCs), which can directly measure muons with very good space and time resolution. The muon detector is shielded by placing it under another detector able to absorb and measure the electromagnetic component of the showers such as a water-Cherenkov detector, commonly used in air shower arrays. The combination of the two detectors in a single, compact detector unit provides a unique measurement that opens rich possibilities in the study of air showers.

Characterization of proton and neutron irradiated low resistivity p-on-n magnetic Czochralski ministrip sensors and diodes

Energy Technology Data Exchange (ETDEWEB)

Pacifico, Nicola, E-mail: nicola.pacifico@cern.ch [CERN, Geneva (Switzerland); Dolenc Kittelmann, Irena; Fahrer, Manuel; Moll, Michael [CERN, Geneva (Switzerland); Militaru, Otilia [UCL, Louvain (Belgium)

2011-12-01

Transient Current Technique (TCT) and Charge Collection Efficiency (CCE) measurements were performed on low resistivity (280{Omega}cm) n-bulk, p-readout magnetic Czochralski ministrip sensors and diodes. The detectors were irradiated with neutrons and 24 GeV/c protons up to a total NIEL equivalent fluence of 8 Multiplication-Sign 10{sup 15}/cm{sup 2}. The study was addressed to assess the radiation tolerance of the detectors up to fluences expected in the next generations of High Energy Physics experiments. The charge collection efficiency after irradiation was found to be much higher than for standard FZ silicon p-in-n sensors. The underlying physics of this remarkable result was investigated by performing Edge-TCT measurements on one of the neutron irradiated ministrip sensors to extract detailed informations about the field and efficiency profiles of the detector.

Characterization of a cable-free system based on p-type MOSFET detectors for "in vivo" entrance skin dose measurements in interventional radiology.

Science.gov (United States)

Falco, Maria Daniela; D'Andrea, Marco; Strigari, Lidia; D'Alessio, Daniela; Quagliani, Francesco; Santoni, Riccardo; Bosco, Alessia Lo

2012-08-01

During radiological interventional procedures (RIP) the skin of a patient under examination may undergo a prolonged x-ray exposure, receiving a dose as high as 5 Gy in a single session. This paper describes the use of the OneDose(TM) cable-free system based on p-type MOSFET detectors to determine the entrance skin dose (ESD) at selected points during RIP. At first, some dosimetric characteristics of the detector, such as reproducibility, linearity, and fading, have been investigated using a C-arc as a source of radiation. The reference setting (RS) was: 80 kV energy, 40 cm × 40 cm field of view (FOV), current-time product of 50 mAs and source to skin distance (SSD) of 50 cm. A calibrated PMX III solid state detector was used as the reference detector and Gafchromic(®) films have been used as an independent dosimetric system to test the entire procedure. A calibration factor for the RS and correction factors as functions of tube voltage and FOV size have been determined. Reproducibility ranged from 4% at low doses (around 10 cGy as measured by the reference detector) to about 1% for high doses (around 2 Gy). The system response was found to be linear with respect to both dose measured with the PMX III and tube voltage. The fading test has shown that the maximum deviation from the optimal reading conditions (3 min after a single irradiation) was 9.1% corresponding to four irradiations in one hour read 3 min after the last exposure. The calibration factor in the RS has shown that the system response at the kV energy range is about four times larger than in the MV energy range. A fifth order and fourth order polynomial functions were found to provide correction factors for tube voltage and FOV size, respectively, in measurement settings different than the RS. ESDs measured with the system after applying the proper correction factors agreed within one standard deviation (SD) with the corresponding ESDs measured with the reference detector. The ESDs measured with

Development of irradiation rig in HTTR and dosimetry method. I-I type irradiation equipment

Energy Technology Data Exchange (ETDEWEB)

Shibata, Taiju; Kikuchi, Takayuki [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment; Miyamoto, Satoshi; Ogura, Kazutomo [Japan Atomic Power Co., Tokyo (Japan)

2002-12-01

The High Temperature Engineering Test Reactor (HTTR) is a graphite-moderated, helium gas-cooled test reactor with a maximum power of 30 MW. The HTTR aims not only to establish and upgrade the technological basis for the HTGRs but also to perform the innovative basic research on high temperature engineering with high temperature irradiation fields. It is planned that the HTTR is used to perform various engineering tests such as the safety demonstration test, high temperature test operation and irradiation test with large irradiation fields at high temperatures. This paper describes the design of the I-I type irradiation equipment developed as the first irradiation rig for the HTTR and does the planned dosimetry method at the first irradiation test. It was developed to perform in-pile creep test on a stainless steel with large standard size specimens in the HTTR. It can give great loads on the specimens stably and can control the irradiation temperature precisely. The in-core creep properties on the specimens are measured by newly developed differential transformers and the irradiation condition in the core is monitored by thermocouples and self-powered neutron detectors (SPNDs), continuously. The irradiated neutron fluence is assessed by neutron fluence monitors of small metallic wires after the irradiation. The obtained data at the first irradiation test can strongly be contributed to upgrade the technological basis for the HTGRs, since it is the first direct measurement of the in-core irradiation environments of the HTTR. (author)

Defect kinetics in novel detector materials

CERN Document Server

MacEvoy, B C

2000-01-01

Silicon particle detectors will be used extensively in experiments at the CERN Large Hadron Collider, where unprecedented particle fluences will cause significant atomic displacement damage. We present a model of the evolution of defect concentrations and consequent electrical behaviour in "novel" detector materials with various oxygen and carbon impurity concentrations. The divacancy-oxygen (V/sub 2/O) defect is identified as the cause of changes in device characteristics during /sup 60/Co gamma irradiation. In the case of hadron irradiation changes in detector doping concentration (N/sub eff/) are dominated by cluster defects, in particular the divacancy (V/sub 2/), which exchange charge directly via a non-Shockley-Read- Hall mechanism. The V/sub 2/O defect also contributes to Ne/sub eff/. This defect is more copiously produced during 24 GeV/c proton irradiation than during 1 MeV neutron irradiation on account of the higher vacancy introduction rate, hence the radiation hardness of materials is more sensiti...

Secondary standard neutron detector for measuring total reaction cross sections

International Nuclear Information System (INIS)

Sekharan, K.K.; Laumer, H.; Gabbard, F.

1975-01-01

A neutron detector has been constructed and calibrated for the accurate measurement of total neutron-production cross sections. The detector consists of a polyethylene sphere of 24'' diameter in which 8- 10 BF 3 counters have been installed radially. The relative efficiency of this detector has been determined for average neutron energies, from 30 keV to 1.5 MeV by counting neutrons from 7 Li(p,n) 7 Be. By adjusting the radial positions of the BF 3 counters in the polyethylene sphere the efficiency for neutron detection was made nearly constant for this energy range. Measurement of absolute efficiency for the same neutron energy range has been done by counting the neutrons from 51 V(p,n) 51 Cr and 57 Fe(p,n) 57 Co reactions and determining the absolute number of residual nuclei produced during the measurement of neutron yield. Details of absolute efficiency measurements and the use of the detector for measurement of total neutron yields from neutron producing reactions such as 23 Na(p,n) 23 Mg are given

Applications of solid-state nuclear track detectors (SSNTDs) for fast ion and fusion reaction product measurements in TEXTOR experiments

Energy Technology Data Exchange (ETDEWEB)

Szydlowski, A.; Malinowski, K.; Malinowska, A. [Association EURTOM-IPPLM Warsaw, The Andrzej Soltan Institute for Nuclear Studies, 05-400 Otwock-Swierk (Poland); Wassenhove, G. Van [EURATOM-Belgium State Association, LPP, ERM/KMS, Trilateral Euregio Cluster, B-1000 Brussels (Belgium); Schweer, B. [Association EURATOM-FZJ, Institutte of Plasma Physicx, Juelich (Germany)

2011-07-01

Full text of publication follows: The paper reports on measurements of fusion reaction protons which were performed on TEXTOR facility in January 2009. The basic experimental scheme was similar to that applied in the previous measurements [1, 2]. The main experimental tool equipment was a small ion pinhole camera which was equipped with a PM-355 detector sample and was attached to a water cooled manipulator. The camera was placed below the plasma ring in the direction of ion drifts, at a distance of 4.4 cm from LCFS. However, in the described experiment it was aligned at an angle to the mayor TEXTOR radius (contrary to previous experiments), so that the input pinhole was oriented first at {gamma} = 45 degrees (shots 108799 - 108818) and then {gamma} = 600 (shots 108832 - 108847). The discharges were executed with one neutral beam of the total power 0.6 - 1.0 MW. In the first series (Nos 108799 - 108818) the plasma was additionally heated by ICRH of frequency 38 MHz. The irradiated detector samples were subjected to the same interrupted etching procedure as the samples used in the CR-39/PM-355 detector calibration measurements [1, 2]. After that, track density distributions and track diameter histograms were measured under an optical microscope. By the use of the calibration curves, it was possible to distinguish craters produced by protons from other craters and to convert the obtained histograms into proton energy spectra. The craters induced by lower energy ions appeared to be concentrated in narrower areas, whereas higher energy ions were registered in a more diffused detector fields. The paper shows again that the CR-39/PM-355 detector is an useful diagnostic tool for tokamak experiments, for measurement of charged ions. References: [1] A. Szydlowski, A. Malinowska, M. Jaskola, A. Korman, M.J. Sadowski, G. Van Wassenhove, B. Schweer and the TEXTOR team, A. Galkowski, 'Application of Solid State Nuclear Track Detectors in TEXTOR Experiment for Measurements

Damage induced in semiconductors by swift heavy ion irradiation

International Nuclear Information System (INIS)

Levalois, M.; Marie, P.

1999-01-01

The behaviour of semiconductors under swift heavy ion irradiation is different from that of metals or insulators: no spectacular effect induced by the inelastic energy loss has been reported in these materials. We present here a review of irradiation effects in the usual semiconductors (silicon, germanium and gallium arsenide). The damage is investigated by means of electrical measurements. The usual mechanisms of point defect creation can account for the experimental results. Besides, some results obtained on the wide gap semiconductor silicon carbide are reported. Concerning the irradiation effects induced by heavy ions in particle detectors, based on silicon substrate, we show that the deterioration of the detector performances can be explained from the knowledge of the substrate properties which are strongly perturbed after high doses of irradiation. Finally, some future ways of investigation are proposed. The silicon substrate is a good example to compare the irradiation effects with different particles such as electrons, neutrons and heavy ions. It is then necessary to use parameters which account for the local energy deposition, in order to describe the damage in the material

Efficiency measurement of the NeuLAND detector

Energy Technology Data Exchange (ETDEWEB)

Toernqvist, Hans; Atar, Leyla; Aumann, Thomas; Holl, Matthias; Horvat, Andrea; Kahlbow, Julian; Miki, Kenjiro; Rossi, Dominic; Scheit, Heiko; Schindler, Fabia [Institut fuer Kernphysik, Technische Universitaet Darmstadt, Darmstadt (Germany); Boretzky, Konstanze; Caesar, Christoph; Simon, Haik [GSI Gesellschaft fuer Schwerionenforschung GmbH, Darmstadt (Germany); Gasparic, Igor [Ruder Boskovic Institute, Zagreb (Croatia); Collaboration: R3B-Collaboration

2016-07-01

NeuLAND is the next-generation high-energy and high-efficiency neutron detector currently under construction at GSI/FAIR by the R{sup 3}B collaboration. This detector will be used in a wide variety of experiments, ranging from nuclear-structure measurements of neutron-rich species to the investigation of the equation-of-state of asymmetric nuclear matter. The design goals of the full NeuLAND detector are a >95% detection efficiency for single neutrons, a time resolution of σ{sub t} ≤ 150 ps and a position resolution of σ{sub x,y,z} ≤ 1.5 cm, with a detection volume of 250 x 250 x 300 cm{sup 3}. While still under construction, a set of 4 of the 30 planned NeuLAND double-planes were used for a series of experiments at the SAMURAI setup at RIKEN. In particular, the time resolution and one-neutron efficiency were measured using neutrons from the {sup 7}Li(p,n){sup 7}Be reaction. The test setup at RIKEN are described, and the resolution and efficiency results are discussed.

Advances in the project about Pin type silicon radiation detectors

International Nuclear Information System (INIS)

Ramirez F, J.; Cerdeira, A.; Aceves, M.; Diaz, A.; Estrada, M.; Rosales, P.; Cabal, A.E.; Montano L, M.; Leyva, A.

1998-01-01

The obtained advances in the collaboration project ININ-CINVESTAV about development of Pin type semiconductor radiation detectors here are presented. It has been characterized the response to different types of radiation made in CINVESTAV and INAOE. Measurements have been realized with different types of sensitive to charge preamplifiers determining the main characteristics which must be executed to be able to be employed with low capacitance detectors. As applications it has been possible to measure the irradiation time in a mammography machine and X-ray energy spectra have been obtained in the order of 14 KeV, with 4 KeV at ambient temperature. The future actions of project have been indicated and the possible applications of these detectors. (Author)

30 CFR 75.320 - Air quality detectors and measurement devices.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Air quality detectors and measurement devices... COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.320 Air quality detectors and measurement devices. (a) Tests for methane shall be made by a qualified person with...

Calibration of time of flight detectors using laser-driven neutron source

Energy Technology Data Exchange (ETDEWEB)

Mirfayzi, S. R.; Kar, S., E-mail: s.kar@qub.ac.uk; Ahmed, H.; Green, A.; Alejo, A.; Jung, D. [Centre for Plasma Physics, School of Mathematics and Physics, Queen’s University Belfast, Belfast BT7 1NN (United Kingdom); Krygier, A. G.; Freeman, R. R. [Department of Physics, The Ohio State University, Columbus, Ohio 43210 (United States); Clarke, R. [Central Laser Facility, Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0QX (United Kingdom); Fuchs, J.; Vassura, L. [LULI, Ecole Polytechnique, CNRS, Route de Saclay, 91128 Palaiseau Cedex (France); Kleinschmidt, A.; Roth, M. [Institut für Kernphysik, Technische Universität Darmstadt, Schloßgartenstrasse 9, D-64289 Darmstadt,Germany (Germany); Morrison, J. T. [Propulsion Systems Directorate, Air Force Research Lab, Wright Patterson Air Force Base, Ohio 45433 (United States); Najmudin, Z.; Nakamura, H. [Blackett Laboratory, Department of Physics, Imperial College, London SW7 2AZ (United Kingdom); Norreys, P. [Central Laser Facility, Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0QX (United Kingdom); Department of Physics, University of Oxford, Oxford OX1 3PU (United Kingdom); Oliver, M. [Department of Physics, University of Oxford, Oxford OX1 3PU (United Kingdom); Zepf, M. [Centre for Plasma Physics, School of Mathematics and Physics, Queen’s University Belfast, Belfast BT7 1NN (United Kingdom); Helmholtz Institut Jena, D-07743 Jena (Germany); Borghesi, M. [Centre for Plasma Physics, School of Mathematics and Physics, Queen’s University Belfast, Belfast BT7 1NN (United Kingdom); Institute of Physics of the ASCR, ELI-Beamlines Project, Na Slovance 2, 18221 Prague (Czech Republic)

2015-07-15

Calibration of three scintillators (EJ232Q, BC422Q, and EJ410) in a time-of-flight arrangement using a laser drive-neutron source is presented. The three plastic scintillator detectors were calibrated with gamma insensitive bubble detector spectrometers, which were absolutely calibrated over a wide range of neutron energies ranging from sub-MeV to 20 MeV. A typical set of data obtained simultaneously by the detectors is shown, measuring the neutron spectrum emitted from a petawatt laser irradiated thin foil.

Calibration of time of flight detectors using laser-driven neutron source

Science.gov (United States)

Mirfayzi, S. R.; Kar, S.; Ahmed, H.; Krygier, A. G.; Green, A.; Alejo, A.; Clarke, R.; Freeman, R. R.; Fuchs, J.; Jung, D.; Kleinschmidt, A.; Morrison, J. T.; Najmudin, Z.; Nakamura, H.; Norreys, P.; Oliver, M.; Roth, M.; Vassura, L.; Zepf, M.; Borghesi, M.

2015-07-01

Calibration of three scintillators (EJ232Q, BC422Q, and EJ410) in a time-of-flight arrangement using a laser drive-neutron source is presented. The three plastic scintillator detectors were calibrated with gamma insensitive bubble detector spectrometers, which were absolutely calibrated over a wide range of neutron energies ranging from sub-MeV to 20 MeV. A typical set of data obtained simultaneously by the detectors is shown, measuring the neutron spectrum emitted from a petawatt laser irradiated thin foil.

Calibration of time of flight detectors using laser-driven neutron source

International Nuclear Information System (INIS)

Mirfayzi, S. R.; Kar, S.; Ahmed, H.; Green, A.; Alejo, A.; Jung, D.; Krygier, A. G.; Freeman, R. R.; Clarke, R.; Fuchs, J.; Vassura, L.; Kleinschmidt, A.; Roth, M.; Morrison, J. T.; Najmudin, Z.; Nakamura, H.; Norreys, P.; Oliver, M.; Zepf, M.; Borghesi, M.

2015-01-01

Calibration of three scintillators (EJ232Q, BC422Q, and EJ410) in a time-of-flight arrangement using a laser drive-neutron source is presented. The three plastic scintillator detectors were calibrated with gamma insensitive bubble detector spectrometers, which were absolutely calibrated over a wide range of neutron energies ranging from sub-MeV to 20 MeV. A typical set of data obtained simultaneously by the detectors is shown, measuring the neutron spectrum emitted from a petawatt laser irradiated thin foil

3D silicon pixel detectors for the High-Luminosity LHC

CERN Document Server

Lange, J.

2016-01-01

3D silicon pixel detectors have been investigated as radiation-hard candidates for the innermost layers of the HL-LHC upgrade of the ATLAS pixel detector. 3D detectors are already in use today in the ATLAS IBL and AFP experiments. These are based on 50x250 um2 large pixels connected to the FE-I4 readout chip. Detectors of this generation were irradiated to HL-LHC fluences and demonstrated excellent radiation hardness with operational voltages as low as 180 V and power dissipation of 12--15 mW/cm2 at a fluence of about 1e16 neq/cm2, measured at -25 degree C. Moreover, to cope with the higher occupancies expected at the HL-LHC, a first run of a new generation of 3D detectors designed for the HL-LHC was produced at CNM with small pixel sizes of 50x50 and 25x100 um2, matched to the FE-I4 chip. They demonstrated a good performance in the laboratory and in beam tests with hit efficiencies of about 97% at already 1--2V before irradiation.

Irradiation test of mirror samples for the LHCb SciFi tracker

CERN Document Server

Joram, Christian; Gavardi, Laura; Ravotti, Federico; Schneider, Thomas

2016-01-01

The optical mirrors at the inner ends of the SciFi fibre modules in the upgraded LHCb detector will be exposed to an ionising dose reaching 35 kGy for an integrated luminosity of 50 /fb. This note describes a campaign at the cyclotron at KIT where 7 different samples were irradiated with 23 MeV protons. The samples consisted of plastic scintillator tiles, on which two different mirror foils – aluminised mylar and 3M ESR - were attached with two different glues – Epotek H301-2FL and Dow Corning RTV 3145. The transmission and/or reflectivity of the samples were measured before and after irradiation. The measurements reveal the combination of 3M ESR foil and Epotek H301-2FL to give the highest reflectivity, before and also after irradiation. In all cases, the irradiation leads only to a small, i.e. less than 10%, degradation of the transmission or reflectivity. From a radiation hardness point of view, all investigated mirror samples qualify for use in the SciFi detector.

Assessment of MicroDiamond PTW 60019 detector and its comparison with other detectors for relative dosimetry in small radiosurgery fields of the Leksell gamma knife perfexion

International Nuclear Information System (INIS)

Novotny, J. Jr.; Kozubikova, P.; Pastykova, V.; Pipek, J.; Bhatnagar, J. P.; Huq, M. S.; Veselsky, T.

2014-01-01

Measurement of relative output factors (ROF) for the Leksell Gamma Knife (LGK) is not a trivial task due to strict demands of an accurate set up and small size of measured radiosurgery fields. The purpose of this study was to perform an assessment of a new synthetic single crystal MicroDiamond PTW 60019 detector (volume 0.004 mm 3 ) for measurement of ROFs for 4 mm and 8 mm collimators for the LGK Perfexion. Small sensitive volume of this detector, near water equivalence and low energy dependence make it an attractive candidate for small field dosimetry. Results obtained in this study were compared with results measured by broad variety of different detectors and also Monte Carlo (MC) simulation. MicroDiamond detector connected to PTW UNIDOS electrometer was positioned in ELEKTA spherical phantom and pre-irradiated to dose of 5 Gy. Measurements were performed in two different detector positions: 1) parallel with table axis, 2) orthogonal to table axis. Electrometer timer of 1 min was used to measure subsequently signal from 16 mm, 8 mm and 4 mm beams. Altogether ten measurements were performed for each of three collimator sizes. Results from MicroDiamond were compared with those obtained from various types of detectors used in the past by authors for measurement of LGK ROFs. New synthetic single crystal MicroDiamond PTW 60019 detector appears to be a very promising detector for relative output factor measurements in very small radiosurgery fields. (authors)

Exclusive ρ0 production measured with the HERMES recoil detector

International Nuclear Information System (INIS)

Perez Benito, Roberto Francisco

2010-12-01

The Hermes experiment (HERa MEasurement of Spin) at Desy was designed to study the spin structure of the nucleon in semi-inclusive deep inelastic scattering. The internal structure of the nucleon has been investigated in detail and it has been measured that the intrinsic quark spin contribution is only about 30% of the total spin of the nucleon. A formalism to describe the internal structure of the nucleon called Generalised Patron Distributions (GPDs) was developed recently to understand the fundamental structure of the nucleon. These GPDs can be accessed by the measurement of hard exclusive reactions and hard exclusive processes that can be understood in terms of GPDs. The accumulated Hermes data offer access to GPDs in different combinations of beam charge and beam and target helicity asymmetries. To improve exclusivity and to enhance the resolution of kinematic variables to study hard exclusive processes which provide access to the GPDs and hence to the orbital angular momentum of the quarks, in January 2006 a Recoil Detector was installed that surrounded the internal gas target of the Hermes experiment. The Hermes Recoil Detector consisted of three components: a silicon strip detector inside the vacuum, a scintillating fiber tracker and the photon detector. All three detectors were located inside a solenoidal magnet which provided a 1T longitudinal magnetic field. The Recoil Detector improves the selection of exclusive events by a direct measurement of the momentum and track position of the recoiling particle as well as by rejecting non-exclusive background. This detector was an ideal novel tool to combine energy and position measurements for charged particles in a momentum range of 0.1 to 1.4 GeV/c. The Recoil Detector was fully commissioned and operating. Data was taken continuously until the final Hera shutdown in July of 2007. In this thesis we report on the performance of the Recoil Detector and more specifically about the scintillating fiber tracker

In-core neutron flux measurements at PARR using self powered neutron detector

International Nuclear Information System (INIS)

Hussain, A.; Ansari, S.A.

1989-10-01

This report describes experimental reactor physics measure ments at PARR using the in-core neutron detectors. Rhodium self powered neutron detectors (SPND) were used in the PARR core and several measurements were made aimed at detector calibration, response time determination and neutron flux measurements. The detectors were calibrated at low power using gold foils and full power by the thermal channel. Based on this calibration it was observed that the detector response remains almost linear throughout the power range. The self powered detectors were used for on-line determination of absolute neutron flux in the core as well as the spatial distribution of neutron flux or reactor power. The experimental, axial and horizontal flux mapping results at certain locations in the core are presented. The total response time of rhodium detector was experimentally determined to be about 5 minutes, which agree well with the theoretical results. Because of longer response time of SPND of the detectors it is not possible to use them in the reactor protection system. (author). 10 figs

Cryogenic Semiconductor Detectors: Simulation of Signal Formation & Irradiation Beam Test

CERN Document Server

AUTHOR|(CDS)2091318; Stamoulis, G; Vavougios, D

The Beam Loss Monitoring system of the Large Hadron Collider is responsible for the pro- tection of the machine from damage and for the prevention of a magnet quench. Near the interaction points of the LHC, in the triplet magnets area, the BLMs are sensitive to the collision debris, limiting their ability to distinguish beam loss signal from signal caused due to the collision products. Placing silicon & diamond detectors inside the cold mass of the mag- nets, in liquid helium temperatures, would provide significant improvement to the precision of the measurement of the energy deposition in the superconducting coil of the magnet. To further study the signal formation and the shape of the transient current pulses of the aforementioned detectors in cryogenic temperatures, a simulation application has been developed. The application provides a fast way of determining the electric field components inside the detectors bulk and then introduces an initial charge distribution based on the properties of the radiat...

CVD diamond detectors for ionizing radiation

Science.gov (United States)

Friedl, M.; Adam, W.; Bauer, C.; Berdermann, E.; Bergonzo, P.; Bogani, F.; Borchi, E.; Brambilla, A.; Bruzzi, M.; Colledani, C.; Conway, J.; Dabrowski, W.; Delpierre, P.; Deneuville, A.; Dulinski, W.; van Eijk, B.; Fallou, A.; Fizzotti, F.; Foulon, F.; Gan, K. K.; Gheeraert, E.; Grigoriev, E.; Hallewell, G.; Hall-Wilton, R.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kania, D.; Kaplon, J.; Karl, C.; Kass, R.; Knöpfle, K. T.; Krammer, M.; Logiudice, A.; Lu, R.; Manfredi, P. F.; Manfredotti, C.; Marshall, R. D.; Meier, D.; Mishina, M.; Oh, A.; Pan, L. S.; Palmieri, V. G.; Pernegger, H.; Pernicka, M.; Peitz, A.; Pirollo, S.; Polesello, P.; Pretzl, K.; Re, V.; Riester, J. L.; Roe, S.; Roff, D.; Rudge, A.; Schnetzer, S.; Sciortino, S.; Speziali, V.; Stelzer, H.; Stone, R.; Tapper, R. J.; Tesarek, R.; Thomson, G. B.; Trawick, M.; Trischuk, W.; Vittone, E.; Walsh, A. M.; Wedenig, R.; Weilhammer, P.; Ziock, H.; Zoeller, M.; RD42 Collaboration

1999-10-01

In future HEP accelerators, such as the LHC (CERN), detectors and electronics in the vertex region of the experiments will suffer from extreme radiation. Thus radiation hardness is required for both detectors and electronics to survive in this harsh environment. CVD diamond, which is investigated by the RD42 Collaboration at CERN, can meet these requirements. Samples of up to 2×4 cm2 have been grown and refined for better charge collection properties, which are measured with a β source or in a testbeam. A large number of diamond samples has been irradiated with hadrons to fluences of up to 5×10 15 cm-2 to study the effects of radiation. Both strip and pixel detectors were prepared in various geometries. Samples with strip metallization have been tested with both slow and fast readout electronics, and the first diamond pixel detector proved fully functional with LHC electronics.

Process effects on leakage current of Si-PIN neutron detectors with porous microstructure

Energy Technology Data Exchange (ETDEWEB)

Yu, Baoning; Zhao, Kangkang; Yang, Taotao [Beijing University of Technology, Chaoyang District, Pingleyuan 100, 100124 Beijing (China); Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Ruoshui Road 398, 215123 Suzhou (China); Jiang, Yong; Fan, Xiaoqiang [Institute of Nuclear Physics and Chemistry, CAEP, Mianshan Road 64, 621900 Mianyang (China); Lu, Min [Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Ruoshui Road 398, 215123 Suzhou (China); Han, Jun [Beijing University of Technology, Chaoyang District, Pingleyuan 100, 100124 Beijing (China)

2017-06-15

Using the technique of Microfabrication, such as deep silicon dry etching, lithography, etc. Si-PIN neutron detectors with porous microstructure have been successfully fabricated. In order to lower the leakage current, the key fabrication processes, including the Al windows opening, deep silicon etching and the porous side wall smoothing, have been optimized. The cross-section morphology and current-voltage characteristics have been measured to evaluate the microfabrication processes. With the optimized conditions presented by the measurements, a neutron detector with a leakage current density of 2.67 μA cm{sup -2} at a bias of -20 V is obtained. A preliminary neutron irradiation test with {sup 252}Cf neutron source has also been carried out. The neutron irradiation test shows that the neutron detection efficiency of the microstructured neutron detectors is almost 3.6 times higher than that of the planar ones. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Measurement of the total cross section with ALFA Detector at ATLAS

CERN Document Server

Trzebinski, M; The ATLAS collaboration

2017-01-01

The main goals of the Absolute Luminosity For ATLAS (ALFA) detector is to provide an absolute luminosity and total cross section measurement. The measurement method used, the detector alignment and the quality of the collected data are discussed.

Rad-hard electronics study for SSC detectors

International Nuclear Information System (INIS)

Ekenberg, T.; Dawson, J.; Stevens, A.; Haberichter, W.

1991-01-01

The radiation environment in a SSC detector operating at a luminosity of 10 33 cm -2 s -1 will put stringent requirements on radiation hardness of the electronics. Over the expected 10 year life-time of a large detector, ionizing radiation doses of up to 20 MRad and neutron fluences of 10 16 neutrons/cm 2 are projected. At a luminosity of 10 34 cm -2 s -1 even higher total doses are expected. the effect of this environment have been simulated by exposing CMOS/bulk and CMOS/SOS devices from monolithic processes to neutrons and ionizing radiation. leakage currents, noise variations, and DC characteristics have been measured before and after exposure in order to evaluate the effects of the irradiations. As expected the device characteristics remained virtually unchanged by neutron irradiation, while ionizing radiation caused moderate degradation of performance. 5 refs., 6 figs

Characterization of nanoDot optically stimulated luminescence detectors and high-sensitivity MCP-N thermoluminescent detectors in the 40-300 kVp energy range.

Science.gov (United States)

Poirier, Yannick; Kuznetsova, Svetlana; Villarreal-Barajas, Jose Eduardo

2018-01-01

To investigate empirically the energy dependence of the detector response of two in vivo luminescence detectors, LiF:Mg,Cu,P (MCP-N) high-sensitivity TLDs and Al 2 O 3 :C OSLDs, in the 40-300-kVp energy range in the context of in vivo surface dose measurement. As these detectors become more prevalent in clinical and preclinical in vivo measurements, knowledge of the variation in the empirical dependence of the measured response of these detectors across a wide spectrum of beam qualities is important. We characterized a large range of beam qualities of three different kilovoltage x-ray units: an Xstrahl 300 Orthovoltage unit, a Precision x-Ray X-RAD 320ix biological irradiator, and a Varian On-Board Imaging x-ray unit. The dose to water was measured in air according to the AAPM's Task Group 61 protocol. The OSLDs and TLDs were irradiated under reference conditions on the surface of a water phantom to provide full backscatter conditions. To assess the change in sensitivity in the long term, we separated the in vivo dosimeters of each type into an experimental and a reference group. The experimental dosimeters were irradiated using the kilovoltage x-ray units at each beam quality used in this investigation, while the reference group received a constant 10 cGy irradiation at 6 MV from a Varian clinical linear accelerator. The individual calibration of each detector was verified in cycles where both groups received a 10 cGy irradiation at 6 MV. The nanoDot OSLDs were highly reproducible, with ±1.5% variation in response following >40 measurement cycles. The TLDs lost ~20% of their signal sensitivity over the course of the study. The relative light output per unit dose to water of the MCP-N TLDs did not vary with beam quality for beam qualities with effective energies <50 keV (~150 kVp/6 mm Al). At higher energies, they showed a reduced (~75-85%) light output per unit dose relative to 6 MV x rays. The nanoDot OSLDs exhibited a very strong (120

Assessment of population external irradiation doses with consideration of Rospotrebnadzor bodies equipment for monitoring of photon radiation dose

Directory of Open Access Journals (Sweden)

I. P. Stamat

2016-01-01

Full Text Available This paper provides review of equipment and methodology for measurement of photon radiation dose; analysis of possible reasons for considerable deviation between the Russian Federation population annual effective external irradiation doses and the relevant average global value. Data on Rospotrebnadzor bodies dosimetry equipment used for measurement of gamma radiation dose are collected and systematized. Over 60 kinds of dosimeters are used for monitoring of population external irradiation doses. Most of dosimeters used in the country have gas-discharge detectors (Geiger-Mueller counters, minor biochemical annunciators, etc. which have higher total values of own background level and of space radiation response than the modern dosimeters with scintillation detectors. This feature of dosimeters is apparently one of most plausible reasons of a bit overstating assessment of population external irradiation doses. The options for specification of population external irradiation doses assessment are: correction of gamma radiation dose measurement results with consideration of dosimeters own background level and space radiation response, introduction of more up-to-date dosimeters with scintillation detectors, etc. The most promising direction of research in verification of population external irradiation doses assessment is account of dosimetry equipment.

Influence of damage caused by Kr ions and neutrons on electrical properties of silicon detectors

International Nuclear Information System (INIS)

Croitoru, N.; Gubbini, E.; Rancoita, P.G.; Rattaggi, M.; Seidman, A.

1999-01-01

In this paper, new measurements of physical properties of high-resistivity silicon, used in high-energy detectors, are presented. The obtained data contribute to the understanding of the causes which damage the 2electronic characteristics of the detection systems under irradiation of neutrons and ionized particles (Kr). The Hall effect coefficient (R H ) and resistivity (ρ) measurements as a function of temperature (T), for non-irradiated and irradiated by neutrons and Kr ions, were performed. The measurements of the Hall coefficient and resistivity of non-irradiated samples and irradiated at neutron fluences (PHI≤9.9x10 10 n/cm 2 ) and Kr (PHI≤7.5x10 8 Kr/cm 2 ), have shown that the obtained characteristics, R H (T) and ρ(T), are of the same shape as those known for a silicon single crystal. A slight difference of the slope of ln ρ∼ln T, for neutron- and a large difference for Kr ion irradiation as compared with that of non-irradiated samples, was observed. On increasing the irradiation to PHI larger than the value indicated above, for neutrons and Kr ions, important changes in the physical properties were observed. The resistivity increases with increasing PHI, up to a value of the same order with intrinsic silicon (ρ∼10 5 Ω cm), for both neutron and Kr ion irradiation. The values of R H increase with increasing PHI up to a fluence, for which a change of sign, from negative to positive, occurs. The variation of values of R H and ρ as a function of PHI, for neutrons and Kr ions, is similar, but the characteristics R H (PHI) and ρ(PHI), are displaced. Therefore, larger values of PHI are needed in order to obtain the same values of ρ as those for Kr ion irradiation. The dependence on T of electrical parameters of samples, irradiated at PHI≥9.9x10 10 n/cm 2 (neutrons) and PHI≥7.5x10 8 Kr/cm 3 (ions), cannot be explained, considering the usual theoretical relations. The results, obtained in these experiments, have shown a change of mechanism of

Applicability of viscosity measurement to the detection of irradiated peppers

International Nuclear Information System (INIS)

Hayashi, T.; Todoriki, S.; Kohyama, K.

1996-01-01

Starch is degraded by ionising radiation, resulting in a decrease in viscosity. The viscosities of black and white peppers which contain large amounts of starch are reduced by irradiation so, therefore, viscosity measurement has been proposed as a method to detect the irradiation treatment of these food products. Although detection of irradiated spices by thermoluminescence measurement has been established, it is useful to establish the viscosity measuring technique for detecting irradiated peppers, as this method is carried out widely in the laboratories of food controlling authorities and food processing companies. (author)

Front-side biasing of n-in-p silicon strip detectors

CERN Document Server

Baselga Bacardit, Marta; Dierlamm, Alexander Hermann; Dragicevic, Marko Gerhart; Konig, Axel; Pree, Elias; Metzler, Marius

2018-01-01

Front-side biasing is an alternative method to bias a silicon sensor. Instead of directly applying high voltage to the back-side, one can exploit the conductive properties of the edge region to bias a detector exclusively via top-side connections. This option can be beneficial for the detector design and might help to facilitate the assembly process of modules. The effective bias voltage is affected by the resistance of the edge region and the sensor current. The measurements of n-in-p sensors performed to qualify this concept have shown that the voltage drop emerging from this resistance is negligible before irradiation. After irradiation, however, the resistivity of the edge region increases with fluence and saturates in the region of 10$^{7}\\,\\Omega$ at a fluence of 1$\\,\\cdot\\,10^{15}\\,$n$_{\\textrm{eq}}$cm$^{-2}$. The measurements are complemented by TCAD simulations and interpretations of the observed effects.

Study on the fast neutron sensitivity of thermoluminescent detectors

International Nuclear Information System (INIS)

Szabo, P.P.; Palfalvi, J.

1984-03-01

Fast neutron (14.7 MeV) sensitivity of several thermoluminescent detectors was determined. The investigated detectors were MTS-N type pellets (made in Poland) used routinely in the authors' institute for personnel dosimetry, 7 LiF powder used for accident dosimetry, CaSO 4 :Dy and CaSO 4 :Tm powders (made in Hungary) used for enviromental monitoring and space dosimetry. Both free-in-air and on-phantom irradiations were performed. The new results are compared with responses calculated and measured earlier. (author)

Radiation Effects of n-type, Low Resistivity, Spiral Silicon Drift Detector Hybrid Systems

International Nuclear Information System (INIS)

Chen, W.; De Geronimo, G.; Carini, G.A.; Gaskin, J.A.; Keister, J.W.; Li, S.; Li, Z.; Ramsey, B.D.; Siddons, D.P.; Smith, G.C.; Verbitskaya, E.

2011-01-01

We have developed a new thin-window, n-type, low-resistivity, spiral silicon drift detector (SDD) array - to be used as an extraterrestrial X-ray spectrometer (in varying environments) for NASA. To achieve low-energy response, a thin SDD entrance window was produced using a previously developed method. These thin-window devices were also produced on lower resistivity, thinner, n-type, silicon material, effectively ensuring their radiation hardness in anticipation of operation in potentially harsh radiation environments (such as found around the Jupiter system). Using the Indiana University Cyclotron Facility beam line RERS1, we irradiated a set of suitable diodes up to 5 Mrad and the latest iteration of our ASICs up to 12 Mrad. Then we irradiated two hybrid detectors consisting of newly, such-produced in-house (BNL) SDD chips bonded with ASICs with doses of 0.25 Mrad and 1 Mrad. Also we irradiated another hybrid detector consisting of previously produced (by KETEK) on n-type, high-resistivity SDD chip bonded with BNL's ASICs with a dose of 1 Mrad. The measurement results of radiated diodes (up to 5 Mrad), ASICs (up to 12 Mrad) and hybrid detectors (up to 1 Mrad) are presented here.

Characterization of saturation of CR-39 detector at high alpha-particle fluence

Directory of Open Access Journals (Sweden)

M. El Ghazaly

2018-04-01

Full Text Available The occurrence of saturation in the CR-39 detector reduces and limits its detection dynamic range; nevertheless, this range could be extended using spectroscopic techniques and by measuring the net bulk rate of the saturated CR-39 detector surface. CR-39 detectors were irradiated by 1.5 MeV high alpha-particle fluence varying from 0.06 × 108 to 7.36 × 108 alphas/cm2 from Am-241 source; thereafter, they were etched in a 6.25N NaOH solution at a temperature of 70°C for different durations. Net bulk etch rate measurement of the 1.5 MeV alpha-irradiated CR-39 detector surface revealed that rate increases with increasing etching time and reaches its maximum value at the end of the alpha-particle range. It is also correlated with the alpha-particle fluence. The measurements of UV–Visible (UV–Vis absorbance at 500 and 600 nm reveal that the absorbance is linearly correlated with the fluence of alpha particles at the etching times of 2 and 4 hour. For extended etching times of 6, 10, and 14.5 hour, the absorbance is saturated for fluence values of 4.05 × 108, 5.30 × 108, and 7.36 × 108 alphas/cm2. These new methods pave the way to extend the dynamic range of polymer-based solid state nuclear track detectors (SSNTDs in measurement of high fluence of heavy ions as well as in radiation dosimetry. Keywords: Alpha Particle, Bulk Etch Rate, CR-39 Detector, Saturated Regime, UV–Vis Spectroscopy

Establishing the fuel burn-up measuring system for 106 irradiated assemblies of Dalat reactor by using gamma spectrometer method

International Nuclear Information System (INIS)

Nguyen Minh Tuan; Pham Quang Huy; Tran Tri Vien; Trang Cao Su; Tran Quoc Duong; Dang Tran Thai Nguyen

2013-01-01

The fuel burn-up is an important parameter needed to be monitored and determined during a reactor operation and fuel management. The fuel burn-up can be calculated using computer codes and experimentally measured. This work presents the theory and experimental method applied to determine the burn-up of the irradiated and 36% enriched VVR-M2 fuel type assemblies of Dalat reactor. The method is based on measurement of Cs-137 absolute specific activity using gamma spectrometer. Designed measuring system consists of a collimator tube, high purity Germanium detector (HPGe) and associated electronics modules and online computer data acquisition system. The obtained results of measurement are comparable with theoretically calculated results. (author)

MTF measurement and analysis of linear array HgCdTe infrared detectors

Science.gov (United States)

Zhang, Tong; Lin, Chun; Chen, Honglei; Sun, Changhong; Lin, Jiamu; Wang, Xi

2018-01-01

The slanted-edge technique is the main method for measurement detectors MTF, however this method is commonly used on planar array detectors. In this paper the authors present a modified slanted-edge method to measure the MTF of linear array HgCdTe detectors. Crosstalk is one of the major factors that degrade the MTF value of such an infrared detector. This paper presents an ion implantation guard-ring structure which was designed to effectively absorb photo-carriers that may laterally defuse between adjacent pixels thereby suppressing crosstalk. Measurement and analysis of the MTF of the linear array detectors with and without a guard-ring were carried out. The experimental results indicated that the ion implantation guard-ring structure effectively suppresses crosstalk and increases MTF value.

Study etching characteristics of a track detector CR-39 with ultraviolet laser irradiation

International Nuclear Information System (INIS)

Dwaikat, Nidal; Iida, Toshiyuki; Sato, Fuminobu; Kato, Yushi; Ishikawa, Ippei; Kada, Wataru; Kishi, Atsuya; Sakai, Makoto; Ihara, Yohei

2007-01-01

The effect of pulsed ultraviolet Indium-doped Yttrium Aluminum Garnet (UV-In:YAG) laser of λ=266 nm, pulse energy 42 mJ/pulse at repetition rate10 Hz on the etching characteristics of Japanese CR-39 was studied at various energy intensities. Fifteen detectors were divided into two sets, each of seven samples and one sample was kept as a reference.The first set (post-exposed) was first exposed to alpha radiation with close contact to 241 Am and then treated in air with laser in the energy intensity range from 40 to160 J/cm 2 , 20 J/cm 2 in step. The second set (pre-exposed) was irradiated in reverse process (laser+alpha) with the same sources as the first set and under the same condition. The laser energy intensities ranged between 20 and 140 J/cm 2 , 20 J/cm 2 in step. For post-exposed samples (alpha+laser) bulk etch rate decreases up to 60 J/cm 2 and increases thereafter, while for pre-exposed samples (laser+alpha) the bulk etch rate oscillates without showing any precise periodicity. The bulk etch rate for both sets was found to be the same at 60≤energy intensity≤80 J/cm 2 and this may indicate that the same structural changes have happened. The track etch rate was found to be equal to the bulk etch rate for both sets, so the sensitivity is constant. In both sets several changes on the detector surfaces: tracks of different sizes and shapes and high density within the laser spot were observed. Out of the laser spot, the tracks become larger and lower density, indicating cross-linking and scission have happened, simultaneously, on the same surface as a result of UV-laser irradiation

The radiation field in the New Gamma Irradiation Facility GIF++ at CERN

CERN Document Server

Pfeiffer, Dorothea

2017-09-11

The high-luminosity LHC (HL-LHC) upgrade is setting now a new challenge for particle detector technologies. The increase in luminosity will produce a particle background in the gas-based muon detectors that is ten times higher than under conditions at the LHC. The detailed knowledge of the detector performance in the presence of such a high background is crucial for an optimized design and efficient operation after the HL-LHC upgrade. A precise understanding of possible aging effects of detector materials and gases is of extreme importance. To cope with these challenging requirements, a new Gamma Irradiation Facility (GIF++) was designed and built at the CERN SPS North Area as successor of the Gamma Irradiation Facility (GIF) during the Long Shutdown 1 (LS1) period. It features an intense source of 662 keV photons with adjustable intensity, to simulate continuous background over large areas, and, combined with a high energy muon beam, to measure detector performance in the presence of the background. The new ...

Thermo-dynamical measurements for ATLAS Inner Detector (evaporative cooling system)

CERN Document Server

Bitadze, Alexander; Buttar, Craig

During the construction, installation and initial operation of the Evaporative Cooling System for the ATLAS Inner Detector SCT Barrel Sub-detector, some performance characteristics were observed to be inconsistent with the original design specifications, therefore the assumptions made in the ATLAS Inner Detector TDR were revisited. The main concern arose because of unexpected pressure drops in the piping system from the end of the detector structure to the distribution racks. The author of this theses made a series of measurements of these pressure drops and the thermal behavior of SCT-Barrel cooling Stave. Tests were performed on the installed detector in the pit, and using a specially assembled full scale replica in the SR1 laboratory at CERN. This test setup has been used to perform extensive tests of the cooling performance of the system including measurements of pressure drops in different parts of system, studies of the thermal profile along the stave pipe for different running conditions / parameters a...

Characterization of Czochralski silicon detectors

OpenAIRE

Luukka, Panja-Riina

2006-01-01

This thesis describes the characterization of irradiated and non-irradiated segmented detectors made of high-resistivity (>1 kΩcm) magnetic Czochralski (MCZ) silicon. It is shown that the radiation hardness (RH) of the protons of these detectors is higher than that of devices made of traditional materials such as Float Zone (FZ) silicon or Diffusion Oxygenated Float Zone (DOFZ) silicon due to the presence of intrinsic oxygen (> 5 × 1017 cm−3). The MCZ devices therefore present an interesting ...

Measuring the Disappearance of Muon Neutrinos with the MINOS Detector

Energy Technology Data Exchange (ETDEWEB)

Radovic, Alexander [Univ. College London, Bloomsbury (United Kingdom)

2013-08-01

MINOS is a long baseline neutrino oscillation experiment. It measures the flux from the predominately muon neutrino NuMI beam first 1 km from beam start and then again 735 km later using a pair of steel scintillator tracking calorimeters. The comparison of measured neutrino energy spectra at our Far Detector with the prediction based on our Near Detector measurement allows for a measurement of the parameters which define neutrino oscillations. This thesis will describe the most recent measurement of muon neutrino disappearance in the NuMI muon neutrino beam using the MINOS experiment.

Comparison of phoswich and ARSA-type detectors for radioxenon measurements

International Nuclear Information System (INIS)

Ward, R.M.; Biegalski, S.R.F.; Hennig, W.

2009-01-01

The monitoring of atmospheric radioxenon to ensure compliance with the Comprehensive Nuclear Test Ban Treaty (CTBT) has driven the development of improved detectors for measuring xenon, including the development of a phoswich detector. This detector uses only one PMT to detect β-γ coincidence, thus greatly reducing the bulk and electronics of the detector in comparison to the ARSA-type detector. In this experiment, 135 Xe was produced through neutron activation and a phoswich detector was used to attain spectra from the gas. These results were compared to similar results from an ARSA-type β-γ coincidence spectrum. The spectral characteristics and resolution were compared for the coincidence and beta spectra. Using these metrics, the overall performance of the phoswich detector for β-γ coincidence of radioxenon was evaluated. (author)

Detection of irradiated potato and garlic by thermoluminescence measurement

International Nuclear Information System (INIS)

Chung, H.W.; Kwon, J.H.

1998-01-01

Potato and garlic irradiated with gamma ray and electron beam at sprout-inhibition doses, 0.15 and 0.30 kGy were subjected to the detection whether they are irradiated or not by measuring thermoluminescence(TL) for the minerals adhering to the samples. Minerals extracted from the samples showed a high correlation coefficients between absorbed doses and corresponding TL responses. Nonirradiated samples, however, did not exhibit characteristic TL glowcurves. Major glowcurve peaks were observed at 200 to in all irradiated samples. TL intensity was proportional to irradiated doses, but it varied with the samples tested even at the same dose. It can be concluded from the results that detection of irradiated potato and garlic is possible by measuring TL for extracted minerals from the unknown samples

Characterization of a radiation detector for aircraft measurements

International Nuclear Information System (INIS)

Holanda M, L. de; Federico, C. A.; Caldas, L. V. E.

2014-08-01

Air crews, as pilots and flight attendants, are subjected to cosmic ray doses which can be higher than the average doses on workers from the nuclear industry. The diversity of particles of high energies present in the radiation field on board of air crafts turns the determination of the incident dose difficult, and requires special care regarding dosimetric systems to be used in this kind of radiation field. The Brazilian Air Force, through its Institute for Advanced Studies (Instituto de Estudos Avancados, IEAv/DCTA) in conjunction with the Institute of Energetic and Nuclear Research (Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP) are working on this subject since 2008. A prototype of a radiation detector for aircraft measurements was previously built and tested in flight and laboratory conditions. The detector is able of measuring a quantity known as absorbed dose (using passive dosimeters), which will subsequently be correlated to the ambient dose equivalent and the effective dose received by air crews. In this context, a theoretical approach through Monte Carlo simulations with the computational codes MCNP5 and MCNPX was used to model and characterize the detector response at such experimental conditions. This work presents the preliminary results of the computational modeling, with special emphasis on the comparison between the absorbed doses measured and simulated, and its relationship with the ambient dose equivalent and the effective dose for this detector. (author)

Characterization of a radiation detector for aircraft measurements

Energy Technology Data Exchange (ETDEWEB)

Holanda M, L. de; Federico, C. A.; Caldas, L. V. E., E-mail: lcaldas@ipen.br [Instituto de Pesquisas Energeticas e Nucleares, Av. Lineu Prestes 2242, Cidade Universitaria, CEP 05508-000, Sao Paulo (Brazil)

2014-08-15

Air crews, as pilots and flight attendants, are subjected to cosmic ray doses which can be higher than the average doses on workers from the nuclear industry. The diversity of particles of high energies present in the radiation field on board of air crafts turns the determination of the incident dose difficult, and requires special care regarding dosimetric systems to be used in this kind of radiation field. The Brazilian Air Force, through its Institute for Advanced Studies (Instituto de Estudos Avancados, IEAv/DCTA) in conjunction with the Institute of Energetic and Nuclear Research (Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP) are working on this subject since 2008. A prototype of a radiation detector for aircraft measurements was previously built and tested in flight and laboratory conditions. The detector is able of measuring a quantity known as absorbed dose (using passive dosimeters), which will subsequently be correlated to the ambient dose equivalent and the effective dose received by air crews. In this context, a theoretical approach through Monte Carlo simulations with the computational codes MCNP5 and MCNPX was used to model and characterize the detector response at such experimental conditions. This work presents the preliminary results of the computational modeling, with special emphasis on the comparison between the absorbed doses measured and simulated, and its relationship with the ambient dose equivalent and the effective dose for this detector. (author)

Laser measurement of the LumiCal detector displacement

International Nuclear Information System (INIS)

Blocki, J.; Daniluk, W.; Gil, M.; Karbowiak, M.; Moszczynski, A.; Oliwa, K.; Pawlik, B.; Wierba, W.; Zawiejski, L.; Slominski, W.; Suszycki, L.

2006-12-01

The silicon-tungsten calorimeter LumiCal, located in very forward region of the future detector at the International Linear Collider, is proposed for precisely luminosity measurement. One of the requirements to fulfil this task is available information on the actual position of the calorimeter relative to the beam interaction area which should be known with accuracy of a few micrometers. In this paper we discuss the possible solutions for the positioning of the LumiCal electron detector by optical method. The results of the displacement measurement using a laser beam and a CCD camera are described. The measurements were performed on a proof-of-principle basis and achieved the accuracy of about ± 1 μm in x, y and ± μm in z direction. (author)

Calibration of SSNDT detectors for radon measurements

International Nuclear Information System (INIS)

Takahashi, Laura C.; Santos, Talita O.; Pinheiro, Rose Mary M.; Rocha, Zildete

2017-01-01

The methods and instrumentation used to measure the concentration of radon need to be calibrated to obtain accurate results. The Nuclear Track Detector is considered the main method of analysis of radon research. Thus, the Natural Radioactivity Laboratory of the Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG, Brazil) uses the detector CR-39 (Landauer) to measure the concentration of radon in homes, workplaces, underground mines, soils and in environment. Epidemiological studies reveal the strong relationship between lung cancer and radon exposure. Therefore, it is important to monitor this gas and its progeny in order to assess the radiological risk. The alpha particles emitted by radon and its progeny leave traces on CR-39 due to Coulombian interactions with the atoms of the material. The liquid density of traces is converted to radon concentration by means of a calibration factor obtained in calibrated systems. This work aims to determine the LRN / CDTN calibration factor. To do so, the CR-39 detectors were placed inside the calibration chambers, along with two AlphaGUARD (Saphymo GmbH) detectors and Ra-266 sources with activities of 3,379 kBq or 0.483 kBq, referenced by NIST. From this, six levels of exposure were obtained, which were: 44 kBq.d.m 3 , 4 kBq.d.m 3 , 3 kBq.d.m 3 , 15 kBq.d.m 3 , 30 kBq.d.m 3 , 26 kBq.d.m 3 . The conversion factor between the liquid density of traces and the total exposure time obtained was K = 52.028 ± 0.752 [(trace density.cm -2 ) / (kBq.d.m -3 )]. After the determination of the conversion factor, it was used to measure the concentration of radon in underground mines, obtaining concentration results between 122 ± 24 and 7384 ± 517 kBq.m -3

Bubble detector measurements of a mixed radiation field from antiproton annihilation

International Nuclear Information System (INIS)

Bassler, Niels; Knudsen, Helge; Moller, Soren Pape; Petersen, Jorgen B.; Rahbek, Dennis; Uggerhoj, Ulrik I.

2006-01-01

In the light of recent progress in the study of the biological potential of antiproton tumour treatment it is important to be able to characterize the neutron intensity arising from antiproton annihilation using simple, compact and reliable detectors. The intensity of fast neutrons from antiproton annihilation on polystyrene has been measured with bubble detectors and a multiplicity has been derived as well as an estimated neutron equivalent dose. Additionally the sensitivity of bubble detectors towards protons was measured

The antiproton depth–dose curve measured with alanine detectors

CERN Document Server

Bassler, Niels; Palmans, Hugo; Holzscheiter, Michael H; Kovacevic, Sandra

2008-01-01

n this paper we report on the measurement of the antiproton depth–dose curve, with alanine detectors. The results are compared with simulations using the particle energy spectrum calculated by FLUKA, and using the track structure model of Hansen and Olsen for conversion of calculated dose into response. A good agreement is observed between the measured and calculated relative effectiveness although an underestimation of the measured values beyond the Bragg-peak remains unexplained. The model prediction of response of alanine towards heavy charged particles encourages future use of the alanine detectors for dosimetry of mixed radiation fields.

Diamond Detector Technology: Status and Perspectives

CERN Document Server

Reichmann, M; Artuso, M; Bachmair, F; Bäni, L; Bartosik, M; Beacham, J; Beck, H; Bellini, V; Belyaev, V; Bentele, B; Berdermann, E; Bergonzo, P; Bes, A; Brom, J-M; Bruzzi, M; Cerv, M; Chiodini, G; Chren, D; Cindro, V; Claus, G; Collot, J; Cumalat, J; Dabrowski, A; D'Alessandro, R; Dauvergne, D; de Boer, W; Dorfer, C; Dünser, M; Eremin, V; Eusebi, R; Forcolin, G; Forneris, J; Frais-Kölbl, H; Gallin-Martel, L; Gallin-Martel, M L; Gan, K K; Gastal, M; Giroletti, C; Goffe, M; Goldstein, J; Golubev, A; Gorišek, A; Grigoriev, E; Grosse-Knetter, J; Grummer, A; Gui, B; Guthoff, M; Haughton, I; Hiti, B; Hits, D; Hoeferkamp, M; Hofmann, T; Hosslet, J; Hostachy, J-Y; Hügging, F; Hutton, C; Jansen, H; Janssen, J; Kagan, H; Kanxheri, K; Kasieczka, G; Kass, R; Kassel, F; Kis, M; Konovalov, V; Kramberger, G; Kuleshov, S; Lacoste, A; Lagomarsino, S; Lo Giudice, A; Lukosi, E; Maazouzi, C; Mandic, I; Mathieu, C; Menichelli, M; Mikuž, M; Morozzi, A; Moss, J; Mountain, R; Murphy, S; Muškinja, M; Oh, A; Oliviero, P; Passeri, D; Pernegger, H; Perrino, R; Picollo, F; Pomorski, M; Potenza, R; Quadt, A; Re, A; Riley, G; Roe, S; Sanz-Becerra, D A; Scaringella, M; Schaefer, D; Schmidt, C J; Schnetzer, S; Sciortino, S; Scorzoni, A; Seidel, S; Servoli, L; Smith, S; Sopko, B; Sopko, V; Spagnolo, S; Spanier, S; Stenson, K; Stone, R; Sutera, C; Tannenwald, B; Taylor, A; Traeger, M; Tromson, D; Trischuk, W; Tuve, C; Uplegger, L; Velthuis, J; Venturi, N; Vittone, E; Wagner, S; Wallny, R; Wang, J C; Weingarten, J; Weiss, C; Wengler, T; Wermes, N; Yamouni, M; Zavrtanik, M

2018-01-01

The planned upgrade of the LHC to the High-Luminosity-LHC will push the luminosity limits above the original design values. Since the current detectors will not be able to cope with this environment ATLAS and CMS are doing research to find more radiation tolerant technologies for their innermost tracking layers. Chemical Vapour Deposition (CVD) diamond is an excellent candidate for this purpose. Detectors out of this material are already established in the highest irradiation regimes for the beam condition monitors at LHC. The RD42 collaboration is leading an effort to use CVD diamonds also as sensor material for the future tracking detectors. The signal behaviour of highly irradiated diamonds is presented as well as the recent study of the signal dependence on incident particle flux. There is also a recent development towards 3D detectors and especially 3D detectors with a pixel readout based on diamond sensors.

Thermal neutron flux measurement using self-powered neutron detector (SPND) at out-core locations of TRIGA PUSPATI Reactor (RTP)

Science.gov (United States)

Ali, Nur Syazwani Mohd; Hamzah, Khaidzir; Mohamad Idris, Faridah; Hairie Rabir, Mohamad

2018-01-01

The thermal neutron flux measurement has been conducted at the out-core location using self-powered neutron detectors (SPNDs). This work represents the first attempt to study SPNDs as neutron flux sensor for developing the fault detection system (FDS) focusing on neutron flux parameters. The study was conducted to test the reliability of the SPND’s signal by measuring the neutron flux through the interaction between neutrons and emitter materials of the SPNDs. Three SPNDs were used to measure the flux at four different radial locations which located at the fission chamber cylinder, 10cm above graphite reflector, between graphite reflector and tank liner and fuel rack. The measurements were conducted at 750 kW reactor power. The outputs from SPNDs were collected through data acquisition system and were corrected to obtain the actual neutron flux due to delayed responses from SPNDs. The measurements showed that thermal neutron flux between fission chamber location near to the tank liner and fuel rack were between 5.18 × 1011 nv to 8.45 × 109 nv. The average thermal neutron flux showed a good agreement with those from previous studies that has been made using simulation at the same core configuration at the nearest irradiation facilities with detector locations.

Measurement of Detector Efficiency for the CZT Monitoring System

Energy Technology Data Exchange (ETDEWEB)

Yoon, Kang Hwa; Kon, Kang Seo; Kim, Jeongin [KHNP, Radiation Health Research Institute, Seoul (Korea, Republic of)

2014-05-15

Evaluation method of using CZT have been being attempted in various places such as AEP(American Electronic Power) etc since EDF(Electricite de France) had apply to the project named 'Source Term Reduction'. CZT can measure source terms on various places in nuclear power plants because it is available at room temperature unless a seperate device and portability is good. Consequently, CZT show good result from analysis of source terms in nuclear power plants. This study found out efficiency of CZT detector that is now researched in CZT Monitoring System for measure source terms on RCS system of domestic old and new nuclear power plants and verified measured efficiency values by comparing to reference efficiency we already know. This study was carried out for finding out detector's efficiency depending on necessary energy in order to save quantitative radioactivity value of source terms. Eventually, this study is to develope CZT Monitoring System measuring CRUD in domestic PWRs primary system or piping system by carrying out in-vivo. Considering error ratio ±20% on radioactivity value of CRM used in measuring and verifying efficiency, measurement of detector Efficiency for the CZT Monitoring System is good. But more various tests is needed than now for an accurate measurement.

Seminar on Detectors and measurements techniques

International Nuclear Information System (INIS)

Holm, E.

2002-01-01

A Nordic Seminar on detectors and radionuclide measurement techniques was held in Lund, Sweden, May 3-4, 2001. The objective was to highlight recent progress and problems for techniques to study environmental radioactivity. It covered the aspect of detector sample geometry's and methods for evaluation of gamma gamma pulse height distributions. Within the field of alpha-spectrometric techniques gridded ionisation chambers, semiconductor detectors and a general description for analysis of alpha-particle-spectra were presented. Recent development in mass spectrometric techniques, AMS (Accelerator Mass Spectrometry) and ICPMS (Inductively Coupled Plasma mass Spectrometry) for long-lived radionuclides was described. Principles for analysis of beta particle emitters, especially by liquid scintillation were presented. The seminar also covered radiochemistry such advantages and disadvantages between ion exchange, solvent extraction and extraction chromatography. The use of controlled laboratory conditions for discerning the dynamics of accumulation in organisms was demonstrated. Other techniques such as neutron activation were also shown to be useful analytical tool for certain long-lived radionuclides. The results of the intercalibration exercises within the Nordic countries showed the importance of such analytical quality control. (au)

Non-streaming high-efficiency perforated semiconductor neutron detectors, methods of making same and measuring wand and detector modules utilizing same

Science.gov (United States)

McGregor, Douglas S.; Shultis, John K.; Rice, Blake B.; McNeil, Walter J.; Solomon, Clell J.; Patterson, Eric L.; Bellinger, Steven L.

2010-12-21

Non-streaming high-efficiency perforated semiconductor neutron detectors, method of making same and measuring wands and detector modules utilizing same are disclosed. The detectors have improved mechanical structure, flattened angular detector responses, and reduced leakage current. A plurality of such detectors can be assembled into imaging arrays, and can be used for neutron radiography, remote neutron sensing, cold neutron imaging, SNM monitoring, and various other applications.

CVD diamond detectors for ionizing radiation

CERN Document Server

Friedl, M; Bauer, C; Berfermann, E; Bergonzo, P; Bogani, F; Borchi, E; Brambilla, A; Bruzzi, Mara; Colledani, C; Conway, J; Dabrowski, W; Delpierre, P A; Deneuville, A; Dulinski, W; van Eijk, B; Fallou, A; Fizzotti, F; Foulon, F; Gan, K K; Gheeraert, E; Grigoriev, E; Hallewell, G D; Hall-Wilton, R; Han, S; Hartjes, F G; Hrubec, Josef; Husson, D; Kagan, H; Kania, D R; Kaplon, J; Karl, C; Kass, R; Knöpfle, K T; Krammer, Manfred; Lo Giudice, A; Lü, R; Manfredi, P F; Manfredotti, C; Marshall, R D; Meier, D; Mishina, M; Oh, A; Pan, L S; Palmieri, V G; Pernegger, H; Pernicka, Manfred; Peitz, A; Pirollo, S; Polesello, P; Pretzl, Klaus P; Re, V; Riester, J L; Roe, S; Roff, D G; Rudge, A; Schnetzer, S R; Sciortino, S; Speziali, V; Stelzer, H; Stone, R; Tapper, R J; Tesarek, R J; Thomson, G B; Trawick, M L; Trischuk, W; Vittone, E; Walsh, A M; Wedenig, R; Weilhammer, Peter; Ziock, H J; Zöller, M

1999-01-01

In future HEP accelerators, such as the LHC (CERN), detectors and electronics in the vertex region of the experiments will suffer from extreme radiation. Thus radiation hardness is required for both detectors and electronics to survive in this harsh environment. CVD diamond, which is investigated by the RD42 Collaboration at CERN, can meet these requirements. Samples of up to 2*4 cm/sup 2/ have been grown and refined for better charge collection properties, which are measured with a beta source or in a test beam. A large number of diamond samples has been irradiated with hadrons to fluences of up to 5*10/sup 15/ cm/sup -2/ to study the effects of radiation. Both strip and pixel detectors were prepared in various geometries. Samples with strip metallization have been tested with both slow and fast readout electronics, and the first diamond pixel detector proved fully functional with LHC electronics. (16 refs).

CVD diamond detectors for ionizing radiation

Energy Technology Data Exchange (ETDEWEB)

Friedl, M. E-mail: markus.friedl@cern.ch; Adam, W.; Bauer, C.; Berdermann, E.; Bergonzo, P.; Bogani, F.; Borchi, E.; Brambilla, A.; Bruzzi, M.; Colledani, C.; Conway, J.; Dabrowski, W.; Delpierre, P.; Deneuville, A.; Dulinski, W.; Eijk, B. van; Fallou, A.; Fizzotti, F.; Foulon, F.; Gan, K.K.; Gheeraert, E.; Grigoriev, E.; Hallewell, G.; Hall-Wilton, R.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kania, D.; Kaplon, J.; Karl, C.; Kass, R.; Knoepfle, K.T.; Krammer, M.; Logiudice, A.; Lu, R.; Manfredi, P.F.; Manfredotti, C.; Marshall, R.D.; Meier, D.; Mishina, M.; Oh, A.; Pan, L.S.; Palmieri, V.G.; Pernegger, H.; Pernicka, M.; Peitz, A.; Pirollo, S.; Polesello, P.; Pretzl, K.; Re, V.; Riester, J.L.; Roe, S.; Roff, D.; Rudge, A.; Schnetzer, S.; Sciortino, S.; Speziali, V.; Stelzer, H.; Stone, R.; Tapper, R.J.; Tesarek, R.; Thomson, G.B.; Trawick, M.; Trischuk, W.; Vittone, E.; Walsh, A.M.; Wedenig, R.; Weilhammer, P.; Ziock, H.; Zoeller, M

1999-10-01

In future HEP accelerators, such as the LHC (CERN), detectors and electronics in the vertex region of the experiments will suffer from extreme radiation. Thus radiation hardness is required for both detectors and electronics to survive in this harsh environment. CVD diamond, which is investigated by the RD42 Collaboration at CERN, can meet these requirements. Samples of up to 2x4 cm{sup 2} have been grown and refined for better charge collection properties, which are measured with a {beta} source or in a test beam. A large number of diamond samples has been irradiated with hadrons to fluences of up to 5x10{sup 15} cm{sup -2} to study the effects of radiation. Both strip and pixel detectors were prepared in various geometries. Samples with strip metallization have been tested with both slow and fast readout electronics, and the first diamond pixel detector proved fully functional with LHC electronics. (author)

BeO-OSL detectors for dose measurements in cell cultures

International Nuclear Information System (INIS)

Andreeff, M.; Freudenberg, R.; Kotzerke, J.; Sommer, D.; Reichelt, U.; Henniger, J.

2009-01-01

Aim: The absorbed dose is an important parameter in experiments involving irradiation of cells in vitro with unsealed radionuclides. Typically, this is estimated with a model calculation, although the results thus obtained cannot be verified. Generally used real-time measurement methods are not applicable in this setting. A new detector material with in vitro suitability is the subject of this work. Methods: Optically-stimulated luminescence (OSL) dosimeters based on beryllium oxide (BeO) were used for dose measurement in cell cultures exposed to unsealed radionuclides. Their qualitative properties (e. g. energy-dependent count rate sensitivity, fading, contamination by radioactive liquids) were determined and compared to the results of a Monte Carlo simulation (using AMOS software). OSL dosimeters were tested in common cell culture setups with a known geometry. Results: Dose reproducibility of the OSL dosimeters was ± 1.5%. Fading at room temperature was 0.07% per day. Dose loss (optically-stimulated deletion) under ambient lighting conditions was 0.5% per minute. The Monte Carlo simulation for the relative sensitivity at different beta energies provided corresponding results to those obtained with the OSL dosimeters. Dose profile measurements using a 6 well plate and 14 ml PP tube showed that the geometry of the cell culture vessel has a marked influence on dose distribution with 188 Re. Conclusion: A new dosimeter system was calibrated with β-emitters of different energy. It turned out as suitable for measuring dose in liquids. The dose profile measurements obtained are suitably precise to be used as a check against theoretical dose calculations. (orig.)

Ship Effect Measurements With Fiber Optic Neutron Detector

International Nuclear Information System (INIS)

King, Kenneth L.; Dean, Rashe A.; Akbar, Shahzad; Kouzes, Richard T.; Woodring, Mitchell L.

2010-01-01

The main objectives of this research project was to assemble, operate, test and characterize an innovatively designed scintillating fiber optic neutron radiation detector manufactured by Innovative American Technology with possible application to the Department of Homeland Security screening for potential radiological and nuclear threats at US borders (Kouzes 2004). One goal of this project was to make measurements of the neutron ship effect for several materials. The Virginia State University DOE FaST/NSF summer student-faculty team made measurements with the fiber optic radiation detector at PNNL above ground to characterize the ship effect from cosmic neutrons, and underground to characterize the muon contribution.

A neutron detector for measurement of total neutron production cross sections

International Nuclear Information System (INIS)

Sekharan, K.K.; Laumer, H.; Kern, B.D.; Gabbard, F.

1976-01-01

A neutron detector has been constructed and calibrated for the accurate measurement of total neutron production cross sections. The detector consists of a polyethylene sphere of 60 cm diameter in which eight 10 BF 3 counters have been installed radially. The relative efficiency of this detector has been determined for average neutron energies from 30 keV to 1.5 MeV by counting neutrons from 7 Li(p, n) 7 Be. By adjusting the radial positions of the BF 3 counters in the polyethylene sphere the efficiency for neutron detection was made nearly constant for this energy range. Measurement of absolute efficiency for the same neutron energy range has been done by counting the neutrons from 51 V(p, n) 51 Cr and 57 Fe(p, n) 57 Co reactions and determining the absolute number of residual nuclei produced during the measurement of neutron yield. Details of absolute efficiency measurements and the use of the detector for determination of neutron production cross sections are given. (Auth.)

The measurement of the radioactive aerosol diameter by position sensitive detectors, 3

International Nuclear Information System (INIS)

Murakami, Hiroyuki; Nakamoto, Atsushi; Kanamori, Masashi; Seki, Akio.

1981-10-01

The measurement of the diameter of radioactive aerosol, in particular plutonium aerosol, is very important for the internal dose estimation. Determination of the diameter of radioactive aerosol is performed by using the position sensitive detectors. Position sensitive semiconductor detectors and Scintillation detectors with IIT tube are used as the position sensitive detector. The filter paper with the radioactive aerosols is contacted to the PSD which is connected to the data processor so that the diameter of the aerosol is calculated from the measured radioactivity. (author)

Decision for counting condition of radioactive waste activities measuring by Ludlum detector

International Nuclear Information System (INIS)

Bambang-Purwanto

2000-01-01

Radioactive waste must measured for activities before be throw out to environment. Measuring will be important in ordered to know activities can be given management direction. For activities radioactive waste on limit threshold value must processed, but for under limit threshold value activities can be throw out to environment. Activities measuring for solid radioactive waste and liquid by (Total, β, γ) Ludlum detector connected Mode-1000 Scaler Counting. Before measuring for solid waste activities was decisioned optimally counting condition, and be obtained are : sample weight 3.5 gram, heating temperature of 125 o C and heating time at 60 minutes. Activities measuring result by total detector ranges from (0.68-0.71) 10 -1 μCi/gram, β detector ranges from (0.24-0.25) 10 -1 μCi/gram and γ detector ranges from (0.35-0.37) μCi/gram

Characterisation of a MOSFET-based detector for dose measurement under megavoltage electron beam radiotherapy

Science.gov (United States)

Jong, W. L.; Ung, N. M.; Tiong, A. H. L.; Rosenfeld, A. B.; Wong, J. H. D.

2018-03-01

The aim of this study is to investigate the fundamental dosimetric characteristics of the MOSkin detector for megavoltage electron beam dosimetry. The reproducibility, linearity, energy dependence, dose rate dependence, depth dose measurement, output factor measurement, and surface dose measurement under megavoltage electron beam were tested. The MOSkin detector showed excellent reproducibility (>98%) and linearity (R2= 1.00) up to 2000 cGy for 4-20 MeV electron beams. The MOSkin detector also showed minimal dose rate dependence (within ±3%) and energy dependence (within ±2%) over the clinical range of electron beams, except for an energy dependence at 4 MeV electron beam. An energy dependence correction factor of 1.075 is needed when the MOSkin detector is used for 4 MeV electron beam. The output factors measured by the MOSkin detector were within ±2% compared to those measured with the EBT3 film and CC13 chamber. The measured depth doses using the MOSkin detector agreed with those measured using the CC13 chamber, except at the build-up region due to the dose volume averaging effect of the CC13 chamber. For surface dose measurements, MOSkin measurements were in agreement within ±3% to those measured using EBT3 film. Measurements using the MOSkin detector were also compared to electron dose calculation algorithms namely the GGPB and eMC algorithms. Both algorithms were in agreement with measurements to within ±2% and ±4% for output factor (except for the 4 × 4 cm2 field size) and surface dose, respectively. With the uncertainties taken into account, the MOSkin detector was found to be a suitable detector for dose measurement under megavoltage electron beam. This has been demonstrated in the in vivo skin dose measurement on patients during electron boost to the breast tumour bed.

Thermal neutron detection by means of an organic solid-state track detector

International Nuclear Information System (INIS)

Doerschel, B.; Streubel, G.

1979-01-01

Thermal neutrons can be detected by means of organic solid-state track detectors if they are combined with radiators in which charged secondary particles are produced in neutron interaction processes. The secondary particles can produce etchable tracks in the detector material. For thermal neutron fluence determination from the track densities, the thermal neutron sensitivity was calculated for cellulose triacetate detectors with LiF radiators, taking into account energy and angular distribution of the alpha particles produced in the LiF radiator. This value is in good agreement with the sensitivity measured during irradiation in different neutron fields if corrections are considered the production of etchable or visuable tracks. Measuring range and measuring accuracy meet the requirements of thermal neutron detection in personnel dosimetry. Possibilities of extending the measuring range are discussed. (author)

Positioning of the detectors inside an anthropomorphic phantom in order to measure the effective dose at workplace

International Nuclear Information System (INIS)

Furstoss, C.; Menard, S.

2006-01-01

Passive and active dosimeters worn on the trunk by the workers exposed to radiation fields at their workplaces measure the personal dose equivalent Hp(10), which was introduced by ICRP 60 to provide an appropriate estimate of the protection quantity: the effective dose E. However, the angular and energy distributions of the radiation fields encountered at workplaces can generate an over or an under-estimation of E because of the response of the dosimeters or/and because of the definition of H p(10) itself. That is why the Institute for Radiological Protection and Nuclear Safety (I.R.S.N.) is evaluating the possibility of the measurement of the effective dose E using an instrumented anthropomorphic phantom. The determination of the effective dose E in mixed neutron/photon fields requires to identify the nature and the energy distribution of the incident fields in order to apply the right radiation weighting factor to the mean absorbed doses. So electronic detectors will have to be placed on the surface and inside the phantom in order to identify the nature of the radiation field and to measure the mean absorbed dose within the organs. The positions and the technical characteristics of the detectors are determined by simulating the spatial distributions of the energy losses within organs and tissues of the phantom. The simulations are carried out with the Monte Carlo code M.C.N.P.X. using mesh tallies (virtual grid superimposed to the phantom geometry) and a mathematical model of an anthropomorphic phantom based on the specifications of Cristy and Eckerman. The processing of the first numerical results corresponding to photon irradiations in standard configurations (A.P., P.A. and L.A.T.) shows that for the following organs: the lungs, the liver, the small intestine and the brain, just one detector is enough and that this detector is not necessarily located at the center of the organ. On the other hand, the determination of the energy deposited in the red bone marrow

A standard fission neutron irradiation facility

International Nuclear Information System (INIS)

Sahasrabudhe, S.G.; Chakraborty, P.P.; Iyer, M.R.; Kirthi, K.N.; Soman, S.D.

1979-01-01

A fission neutron irradiation facility (FISNIF) has been set up at the thermal column of the CIRUS reactor at BARC. The spectrum and the flux have been measured using threshold detectors. The paper describes the setting up of the facility, measurement and application. A concentric cylinder containing UO 2 powder sealed inside surrounds the irradiation point of a pneumatic sample transfer system located in the thermal column of the reactor. Samples are loaded in a standard aluminium capsule with cadmium lining and transported pneumatically. A sample transfer time of 1 s can be achieved in the facility. Typical applications of the facility for studying activation of iron and sodium in fission neutrons are also discussed. (Auth.)

Design Study and Optimization of Irradiation Facilities for Detector and Accelerator Equipment Testing in the SPS North Area at CERN

CERN Document Server

AUTHOR|(CDS)2079748; Stekl, Ivan

Due to increasing performance of LHC during the last years, the strong need of new detector and electronic equipment test areas at CERN appeared from user communities. This thesis reports on two test facilities: GIF++ and H4IRRAD. GIF++, an upgrade of GIF facility, is a combined high-intensity gamma and particle beam irradiation facility for testing detectors for LHC. It combines a high-rate 137Cs source, providing photons with energy of 662 keV, together with the high-energy secondary particle beam from SPS. H4IRRAD is a new mixed-field irradiation area, designed for testing LHC electronic equipment for radiation damage effects. In particular, large volume assemblies such as full electronic racks of high current power converters can be tested. The area uses alternatively an attenuated primary 400 GeV/c proton beam from SPS, or a secondary, mainly proton, beam of 280 GeV/c directed towards a copper target. Different shielding layers are used to reproduce a radiation field similar to the LHC “tunnel” and �...

Measurement of secondary radiation during ion beam therapy with the pixel detector Timepix

Science.gov (United States)

Martišíková, Mária; Jakubek, Jan; Granja, Carlos; Hartmann, Bernadette; Opálka, Lukáš; Pospíšil, Stanislav; Jäkel, Oliver

2011-11-01

In ion beam therapy the finite range of the ion beams in tissue and the presence of the Bragg-peak are exploited. Unpredictable changes in the patient`s condition can alter the range of the ion beam in the body. Therefore it is desired to verify the actual ion range during the treatment, preferably in a non-invasive way. Positron emission tomography (PET) has been used successfully to monitor the applied dose distributions. This method however suffers from limited applicability and low detection efficiency. In order to increase the detection efficiency and to decrease the uncertainties, in this study we investigate the possibility to measure secondary charged particles emerging from the patient during irradiation. An initial experimental study to register the particle radiation coming out of a patient phantom during the therapy was performed at the Heidelberg Ion Beam Therapy Center (HIT) in Germany. A static narrowly-focused beam of carbon ions was directed into a head phantom. The emerging secondary radiation was measured with the position-sensitive Timepix detector outside of the phantom. The detector, developed by the Medipix Collaboration, consists of a silicon sensor bump bonded to a pixelated readout chip (256 × 256 pixels with 55 μm pitch). Together with the USB-based readout interface, Timepix can operate as an active nuclear emulsion registering single particles online with 2D-track visualization. In this contribution we measured the signal behind the head phantom and investigated its dependence on the beam energy (corresponding to beam range in water 2-30 cm). Furthermore, the response was measured at four angles between 0 and 90 degrees. At all investigated energies some signal was registered. Its pattern corresponds to ions. Differences in the total amount of signal for different beam energies were observed. The time-structure of the signal is correlated with that of the incoming beam, showing that we register products of prompt processes. Such

Measurement of secondary radiation during ion beam therapy with the pixel detector Timepix

International Nuclear Information System (INIS)

Martišíková, Mária; Hartmann, Bernadette; Jäkel, Oliver; Jakubek, Jan; Granja, Carlos; Opálka, Lukáš; Pospíšil, Stanislav

2011-01-01

In ion beam therapy the finite range of the ion beams in tissue and the presence of the Bragg-peak are exploited. Unpredictable changes in the patient's condition can alter the range of the ion beam in the body. Therefore it is desired to verify the actual ion range during the treatment, preferably in a non-invasive way. Positron emission tomography (PET) has been used successfully to monitor the applied dose distributions. This method however suffers from limited applicability and low detection efficiency. In order to increase the detection efficiency and to decrease the uncertainties, in this study we investigate the possibility to measure secondary charged particles emerging from the patient during irradiation. An initial experimental study to register the particle radiation coming out of a patient phantom during the therapy was performed at the Heidelberg Ion Beam Therapy Center (HIT) in Germany. A static narrowly-focused beam of carbon ions was directed into a head phantom. The emerging secondary radiation was measured with the position-sensitive Timepix detector outside of the phantom. The detector, developed by the Medipix Collaboration, consists of a silicon sensor bump bonded to a pixelated readout chip (256 × 256 pixels with 55 μm pitch). Together with the USB-based readout interface, Timepix can operate as an active nuclear emulsion registering single particles online with 2D-track visualization. In this contribution we measured the signal behind the head phantom and investigated its dependence on the beam energy (corresponding to beam range in water 2–30 cm). Furthermore, the response was measured at four angles between 0 and 90 degrees. At all investigated energies some signal was registered. Its pattern corresponds to ions. Differences in the total amount of signal for different beam energies were observed. The time-structure of the signal is correlated with that of the incoming beam, showing that we register products of prompt processes. Such

Timing performance measurements of Si-PM-based LGSO phoswich detectors

International Nuclear Information System (INIS)

Yamamoto, Seiichi; Kobayashi, Takahiro; Okumura, Satoshi; Yeom, Jung Yeol

2016-01-01

Since the timing resolution was significantly improved using silicon photomultipliers (Si-PMs) combined with fast scintillators, we expect that phoswich detectors will be used in future TOF-PET systems. However, no practical phoswich detector has been proposed for TOF-PET detectors. We conducted timing performance measurements of phoswich detectors comprised of two types of Ce-doped LGSO scintillators with different decay times coupled to Si-PMs and digitized the output signals using a high bandwidth digital oscilloscope. We prepared three types of LGSOs (LGSO-fast, LGSO-standard, and LGSO-slow) with different Ce concentrations. After measuring the decay time, the energy performance, and the timing performance of each LGSO, we conducted pulse shape analysis and timing resolution measurements for two versions of phoswich LGSOs: LGSO-standard/LGSO-fast and LGSO-slow/LGSO-fast combinations. The pulse shape spectra for a 10-mm-long crystal LGSO-slow/LGSO-fast combination showed good separation of the front and back crystals with a peak-to-valley ratio of 2.0. The timing resolutions for the 20-mm-long crystal LGSO-slow/LGSO-fast combination were ~300 ps FWHM. The timing resolutions for the phoswich LGSOs were slightly inferior than that measured with the individual LGSO fast, but the acquired timing resolution for the phoswich configuration, ~300 ps with a LGSO-slow/LGSO-fast combination, is adequate for TOF-PET systems. We conclude that LGSO phoswich detectors are promising for TOF-DOI-PET systems.

Variance-covariance measurements of anti y/sub D/ for 5.7-MeV neutrons using wall-less spherical detectors

International Nuclear Information System (INIS)

Marino, S.A.; Kliauga, P.; Goldhagen, P.

1988-01-01

Initial results of measurements of anti y/sub D/ for 5.7-MeV neutrons in wall-less spherical detectors, obtained using the variance-covariance (VC) technique, were presented in last year's Annual Report. During the past year, the electrometers have been calibrated and found to be within less than 1% of their nominal value. The VC data have been corrected for electrometer offsets and calibrations. In addition, some measurements were recalculated, excluding runs in which the relative covariance was more than 2.6 times greater than the relative variance (due to large changes in beam intensity from tuning the accelerator during a run). Pulse-height measurements of y were made in the usual manner using the same detectors, and the angle and distance from the target were the same as were used for the VC measurements. Propane-based, tissue-equivalent (TE) gas was used instead of the methane-based TE gas used when the detectors functioned as ionization chambers for the VC method. Calibrations were made using 1.5 keV Al K/sub α/ X rays. Results of the VC and pulse-height measurements are given. The new anti y/sub D/ values for the VC technique are about 7% lower than the previous values, while the pulse-height measurement values are about 25% lower than the corresponding previous values. Lower values of anti y/sub D/ are expected, due to the use of a wall-less chamber, the change from a long, thin cylinder to a sphere, and the change in irradiation angle causing the γ-ray dose fraction to more than double

Neutron measurements on the JET tokamak by means of bubble detectors

International Nuclear Information System (INIS)

Gherendi, M.; Craciunescu, T.; Pantea, A.; Zoita, V.; Edlington, T.; Kiptily, V.; Popovichev, S.; Murari, A.

2009-01-01

Full text: The bubble detectors (superheated fluid detectors - SHFDs) are based on suspensions of superheated fluid droplets which vaporise into bubbles when nucleated by radiation interactions. The active detecting medium is in the form of microscopic (20-50 μm) droplets suspended within an elastic polymer. The bubble detectors are of interest for neutron detection in nuclear fusion devices due to some particular characteristics: - High neutron detection efficiency (counts/unit fluence) that ranges from about 4x10 -2 to 4x10 -5 ; - Almost flat, threshold-type energy response over a broad energy range (10's keV to 10's MeV); - The possibility of having any energy threshold within the above-mentioned energy range; - Practically zero sensitivity to gamma-radiation; - Good spatial resolution (sub-centimetre resolution in the image plane). A series of the neutron measurements have been carried out by means of bubble detectors on the JET tokamak, at Culham Science Centre, Abingdon, UK, during the experimental campaigns C17-C26 (2007-2009). The neutron field parameters (yield, fluence, energy distribution) at a specific location outside the JET Torus Hall have been measured using three types of bubble detectors (BD-PND, DEFENDER, and BDS). The bubble detector measurement location is situated at the end of a vertical collimated line of sight, behind the TOFOR neutron time-of-flight spectrometer. The field-of-view is defined by a variable pre-collimator located on top of the JET tokamak. This paper reports only on the neutron fluence measurements. Spatial (radial and toroidal) distributions of the neutron fluence have been obtained with a two-dimensional array having up to 30 bubble detectors. The operation of the bubble detector array as a neutron pinhole camera having a radial resolution at the JET vacuum chamber mid-plane of about 55 mm was demonstrated in measurements using various openings of the pre-collimator. (authors)

UV sensitivity of various solid state detectors

International Nuclear Information System (INIS)

Knezevic, Zeljka; Ranogajec-Komor, Maria; Miljanic, Saveta

2008-01-01

Full text: The light sensitivity is an important characteristic of solid state passive dosimeters used in individual, clinical and environmental dosimetry. Light sensitivity stands for the response directly induced by visible or UV light in a fully annealed material. For the above mentioned applications a negligible light sensitivity is an advantage. However, high light sensitivity and linear response allows the use of detectors as UV dosimeters. For this purpose various TL detectors and the glass element of the RPL dosemeter type SC-1 were systematically investigated after exposure to UV light (254 and 366 nm) as a function of time. The following solid state detectors were investigated relative to TLD-100: Li 2 B 4 O 7 :Cu,Ag,P LiF:Mg,Cu,P, LiF:Mg,Cu,Si, Al 2 O 3 :C and the glass element of RPL dosimeter. UV irradiations were performed with Camag UV lamp at 254 nm and at 366 nm. The illumination times were 5, 10 and 20 minutes. Day light illumination was also carried out at room temperature over time period of several hours up to 2 weeks. The UV light response of each detector was compared to the response obtained after irradiation with 137 Cs. Al 2 O 3 :C, showed high light sensitivity; after 10 minutes illumination with 254 nm UV light the response was equivalent to 130 mGy 137 Cs gamma irradiation. The 254 nm UV response of LiF:Mg,Cu,P (GR-200 A), as well as TLD-700H and Li 2 B 4 O 7 :Cu,Ag,P were proportional to the time of illumination. The responses after 10 min UV illumination were equivalent to 0.001 mGy, 0.01 mGy and 0.1 mGy 137 Cs gamma irradiation, respectively. The complete SC-1 RPL dosimeter is insensitive to light because the glass element is encapsulated in light protected holder throughout the automatic evaluation process following the annealing (irradiation, preheat, readout). The responses of the previously annealed glass element after 20 min illumination with 254 nm and 366 nm UV light were equivalent to 45μSv and 3 μSv of 137 Cs gamma

Simulation of Heavily Irradiated Silicon Pixel Sensors and Comparison with Test Beam Measurements

CERN Document Server

Chiochia, Vincenzo; Bortoletto, Daniela; Cremaldi, Lucien; Cucciarelli, Susanna; Dorokhov, Andrei; Hoermann, Christoph; Kim, Dongwook; Konecki, Marcin; Kotlinski, Danek; Prokofiev, Kirill; Regenfus, Christian; Rohe, Tilman; Sanders, David A.; Son, Seunghee; Speer, Thomas; Chiochia, Vincenzo; Swartz, Morris; Bortoletto, Daniela; Cremaldi, Lucien; Cucciarelli, Susanna; Dorokhov, Andrei; Hoermann, Christoph; Kim, Dongwook; Konecki, Marcin; Kotlinski, Danek; Prokofiev, Kirill; Regenfus, Christian; Rohe, Tilman; Sanders, David A.; Son, Seunghee; Speer, Thomas

2004-01-01

Charge collection measurements performed on heavily irradiated p-spray DOFZ pixel sensors with a grazing angle hadron beam provide a sensitive determination of the electric field within the detectors. The data are compared with a complete charge transport simulation of the sensor which includes signal trapping and charge induction effects. A linearly varying electric field based upon the standard picture of a constant type-inverted effective doping density is inconsistent with the data. A two-trap double junction model implemented in the ISE TCAD software can be tuned to produce a doubly-peaked electric field which describes the data reasonably well. The modeled field differs somewhat from previous determinations based upon the transient current technique. The model can also account for the level of charge trapping observed in the data.

Proton irradiation of a swept charge device at cryogenic temperature and the subsequent annealing

International Nuclear Information System (INIS)

Gow, J P D; Smith, P H; Hall, D J; Holland, A D; Murray, N J; Pool, P

2015-01-01

A number of studies have demonstrated that a room temperature proton irradiation may not be sufficient to provide an accurate estimation of the impact of the space radiation environment on detector performance. This is a result of the relationship between defect mobility and temperature, causing the performance to vary subject to the temperature history of the device from the point at which it was irradiated. Results measured using Charge Coupled Devices (CCD) irradiated at room temperature therefore tend to differ from those taken when the device was irradiated at a cryogenic temperature, more appropriate considering the operating conditions in space, impacting the prediction of in-flight performance. This paper describes the cryogenic irradiation, and subsequent annealing of an e2v technologies Swept Charge Device (SCD) CCD236 irradiated at −35.4°C with a 10 MeV equivalent proton fluence of 5.0 × 10 8 protons · cm −2 . The CCD236 is a large area (4.4 cm 2 ) X-ray detector that will be flown on-board the Chandrayaan-2 and Hard X-ray Modulation Telescope spacecraft, in the Chandrayaan-2 Large Area Soft X-ray Spectrometer and the Soft X-ray Detector respectively. The SCD is readout continually in order to benefit from intrinsic dither mode clocking, leading to suppression of the surface component of the dark current and allowing the detector to be operated at warmer temperatures than a conventional CCD. The SCD is therefore an excellent choice to test and demonstrate the variation in the impact of irradiation at cryogenic temperatures in comparison to a more typical room temperature irradiation

Temperature detectors on irradiated silicon base

International Nuclear Information System (INIS)

Karimov, M.; Dzhalelov, M.A.; Kurbanov, A.O.

2005-01-01

It is well known, that the most suitable for thermal resistors production is compensated silicon with impurities forming deep lying in forbidden zone, having big negative resistance temperature coefficients (RTC). In the capacity of initial materials for thermal resistors with negative RTC the n-type monocrystalline silicon with specific resistance ∼30 Ω·cm at 300 K is applied. Before the irradiation the phosphorus diffusion is realizing at temperature ∼1000 deg. C for 10 min. Irradiation is putting into practise by WWR-SM reactor fast neutrons within the range (7-10)·10 13 cm -2 . The produced resistors have nominal resistance range (8-20)·10 3 Ω·cm, coefficient of the thermal sensitivity B=4000-6000 deg. C., RTC α 300K =4-6.6 %/grad. It is shown, that offered method allows to obtain same type resistors characteristics on the base of neutron-irradiated material

High rate behavior and discharge limits in micro-pattern detectors

International Nuclear Information System (INIS)

Bressan, A.; Hoch, M.; Pagano, P.; Ropelewski, L.; Sauli, F.; Biagi, S.; Buzulutskov, A.; Gruwe, M.; De Lentdecker, G.; Moermann, D.; Sharma, A.

1999-01-01

We present and discuss a set of systematic measurements, carried out with gaseous proportional micro-pattern detectors, in order to assess their maximum gain when irradiated with high-rate soft X-rays and heavily ionizing alpha particles. The inventory of detectors tested includes: micro-strips, micromegas, micro-dot, gas electron multiplier, CAT (compteur a trous), trench (or groove), micro-CAT (or WELL) detectors, as well as systems with two elements of gaseous amplification in cascade. We confirm the general trend of all single-stage detectors to follow Raether's criterion, i.e. a spontaneous transition from avalanche to streamer, followed by a discharge, when the avalanche size reaches a value of a few 10 7 ; a noticeable exception is the micro-dot counter holding more than 10 8 . In multiple structures, where the gain is shared between two devices in cascade, the maximum overall gain under irradiation is increased by at least one order of magnitude; we speculate this to be a consequence of a voltage dependence of Raether's limit, larger for low operating potentials. Our conclusion is that only multiple devices can guarantee a sufficient margin of reliability for operation in harsh LHC running conditions

Exclusive {rho}{sup 0} production measured with the HERMES recoil detector

Energy Technology Data Exchange (ETDEWEB)

Perez Benito, Roberto Francisco

2010-12-15

The Hermes experiment (HERa MEasurement of Spin) at Desy was designed to study the spin structure of the nucleon in semi-inclusive deep inelastic scattering. The internal structure of the nucleon has been investigated in detail and it has been measured that the intrinsic quark spin contribution is only about 30% of the total spin of the nucleon. A formalism to describe the internal structure of the nucleon called Generalised Patron Distributions (GPDs) was developed recently to understand the fundamental structure of the nucleon. These GPDs can be accessed by the measurement of hard exclusive reactions and hard exclusive processes that can be understood in terms of GPDs. The accumulated Hermes data offer access to GPDs in different combinations of beam charge and beam and target helicity asymmetries. To improve exclusivity and to enhance the resolution of kinematic variables to study hard exclusive processes which provide access to the GPDs and hence to the orbital angular momentum of the quarks, in January 2006 a Recoil Detector was installed that surrounded the internal gas target of the Hermes experiment. The Hermes Recoil Detector consisted of three components: a silicon strip detector inside the vacuum, a scintillating fiber tracker and the photon detector. All three detectors were located inside a solenoidal magnet which provided a 1T longitudinal magnetic field. The Recoil Detector improves the selection of exclusive events by a direct measurement of the momentum and track position of the recoiling particle as well as by rejecting non-exclusive background. This detector was an ideal novel tool to combine energy and position measurements for charged particles in a momentum range of 0.1 to 1.4 GeV/c. The Recoil Detector was fully commissioned and operating. Data was taken continuously until the final Hera shutdown in July of 2007. In this thesis we report on the performance of the Recoil Detector and more specifically about the scintillating fiber tracker

Neutron Focusing Mirrors for Neutron Radiography of Irradiated Nuclear Fuel at Idaho National Laboratory

Science.gov (United States)

Rai, Durgesh K.; Wu, Huarui; Abir, Muhammad; Giglio, Jeffrey; Khaykovich, Boris

Post irradiation examination (PIE) of samples irradiated in nuclear reactors is a challenging but necessary task for the development on novel nuclear power reactors. Idaho National Laboratory (INL) has neutron radiography capabilities, which are especially useful for the PIE of irradiated nuclear fuel. These capabilities are limited due to the extremely high gamma-ray radiation from the irradiated fuel, which precludes the use of standard digital detectors, in turn limiting the ability to do tomography and driving the cost of the measurements. In addition, the small 250 kW Neutron Radiography Reactor (NRAD) provides a relatively weak neutron flux, which leads to low signal-to-noise ratio. In this work, we develop neutron focusing optics suitable for the installation at NRAD. The optics would separate the sample and the detector, potentially allowing for the use of digital radiography detectors, and would provide significant intensity enhancement as well. The optics consist of several coaxial nested Wolter mirrors and is suited for polychromatic thermal neutron radiation. Laboratory Directed Research and Development program of Idaho National Laboratory.

Precise measurement of muon momenta at LEP using the L3 detector

International Nuclear Information System (INIS)

Gonzalez Romero, E.M.

1990-01-01

In this PhD report the author presents the studies and methods developed to achieve the optimization of the resolution in the momentum measurement of the L3 moun detector. Chapters 1 and 2 show the motivations to build a precision muon detector for the LEP e + e - collider. Special emphasis is applied to the study of the Higgs scalar boson search and identification and the guiding principles used to design the L3 muon detector are outlined. Chapter 3 is devoted to the description of the drift chambers. They are located in three concentric octagonal cylinders inside one solenoidal magnet, around the interaction point and coaxial with the beams. These chambers are the measuring elements of the detector. The chapter includes the description or the different tests applied to the chambers to obtain their resolution and calibration. In chapter 4 the alignment system of this chambers is described. This system is a key element to the precision of the detector, that being 12 meters long and of 12 meters of diameter has to measure the particles trajectories with precisions of just a few micrometers. Chapter 5 describes the third key piece for the detector precision, the monitoring and control system. It allows to know continually the precise values of the critical parameters of the detector. Finally in chapter 6 the author presents the results of the many test applied to the detector using cosmic rays, UV lasers and even the actual muons produced in the e + e - interactions. These tests prove that the L3 muon detector is the most precise measuring system for muon momenta installed at present in one e + e - collider ring. (Author)

Study of natural diamond detector spectrometric properties under neutron irradiation

CERN Document Server

Alekseyev, A B; Kaschuck, Y; Krasilnikov, A; Portnov, D; Tugarinov, S

2002-01-01

Natural diamond detector (NDD) performance was studied up to a neutron fluence of 10 sup 1 sup 5 neutron/cm sup 2. The variations of the NDD spectrometric response to incident alpha-particles from sup 2 sup 4 sup 1 Am source after exposure to fast neutron fluences up to 3x10 sup 1 sup 6 n/cm sup 2 were examined. No significant variations up to the level of 10 sup 1 sup 4 n/cm sup 2 were observed. Degradation of charge collection efficiency at higher fluences is reported. No remarkable increase of the NDD leakage current and count rate change had been observed up to a neutron fluence of 3x10 sup 1 sup 6 n/cm sup 2. The charge collection efficiency variations of neutron irradiated diamond spectrometer were studied ex situ under gamma-rays, beta-radiation and visible light excitation. Charge collection efficiency restoration up to 75% level and the NDD performance stabilization by extrinsic low-intensity visible light (550 nm

Development of electron temperature measuring system by silicon drift detector

International Nuclear Information System (INIS)

Song Xianying; Yang Jinwei; Liao Min

2007-12-01

Soft X-ray spectroscopy with two channels Silicon Drift Detector (SDD) are adopted for electron temperature measuring on HL-2A tokamak in 2005. The working principle, design and first operation of the SDD soft X-ray spectroscopy are introduced. The measuring results of electron temperature are also presented. The results show that the SDD is very good detector for electron temperature measuring on HL-2A tokamak. These will become a solid basic work to establish SDD array for electron temperature profiling. (authors)

Radiation damage studies for the DOe silicon detector

International Nuclear Information System (INIS)

Lehner, Frank

2004-01-01

We report on irradiation studies performed on spare production silicon detector modules for the current DOe silicon detector. The lifetime expectations due to radiation damage effects of the existing silicon detector are reviewed. A new upgrade project was started with the goal of a complete replacement of the existing silicon detector. In that context, several investigations on the radiation hardness of new prototype silicon microstrip detectors were carried out. The irradiation on different detector types was performed with 10 MeV protons up to fluences of 10 14 p/cm 2 at the J.R. Mcdonald Laboratory at Kansas State University. The flux calibration was carefully checked using different normalisation techniques. As a result, we observe roughly 40-50% less radiation damage in silicon for 10 MeV p exposure than it is expected by the predicted NIEL scaling

Technological advances in cosmogenic neutron detectors for measuring soil water content

Science.gov (United States)

Zreda, M. G.; Schrön, M.; Köhli, M.

2017-12-01

The cosmic-ray neutron probe is used for measuring area-average soil water content at the hectometer scale. Early work showed a simple exponential decrease with distance of the instrument's sensitivity and a footprint 300 m in radius. Recent research suggested a much higher sensitivity to local neutrons and reduced footprint. We show results confirming the high sensitivity to local neutrons, describe two ways to reduce local and increase far-field effects, and propose ways of measuring neutrons at different spatial scales. Measurements with moderated detectors across a 10-m-wide creek and a 2-m-wide water tank show a decrease by 30% and 20%, respectively, of neutron intensity over water compared to that over land nearby. These results mean that the detector is sensitive to meter-scale heterogeneities of water content. This sensitivity can be reduced by rising the detector or by shielding it from local neutrons. The effect of local water distributions on the measured neutron intensity decreases with height. In the water tank experiment it disappeared almost completely at the height of 2 m, leading to the conjecture that the height roughly equal to the horizontal scale of heterogeneity would eliminate the sensitivity. This may or may not be practical. Shielding the detector below by a hydrogenous material removes a substantial fraction of the local neutrons. The shielded detector has a reduced count rate, reduced sensitivity to local neutrons and increased sensitivity to neutrons farther afield, and a larger footprint. Such a detector could be preferable to the current cosmogenic-neutron probe under heterogeneous soil water conditions. The shielding experiments also inspired the development of a local-area neutron detector. It has hydrogenous neutron shields on all sides except the bottom, substantially blocking the neutrons coming from afar, while allowing the neutrons coming directly from below. Its footprint is equal to its physical dimension when the detector is

Muon flux measurement with silicon detectors in the CERN neutrino beams

International Nuclear Information System (INIS)

Heijne, E.H.M.

1983-01-01

The neutrino beam installations at the CERN SPS accelerator are described, with emphasis on the beam monitoring systems. Especially the muon flux measurement system is considered in detail, and the calibration procedure and systematic aspects of the measurements are discussed. An introduction is given to the use of silicon semiconductor detectors and their related electronics. Other special chapters concern non-linear phenomena in the silicon detectors, radiation damage in silicon detectors, energy loss and energy deposition in silicon and a review of energy loss phenomena for high energy muons in matter. (orig.)

The γ rays sensitivity measurement of CeF3 scintillator detector

International Nuclear Information System (INIS)

Hu Mengchun; Zhou Dianzhong; Li Rurong; Wang Zhentong; Yang Hongqiong; Zhang Jianhua; Hu Qingyuan; Peng Taiping

2003-01-01

The CeF 3 is an abio-scintillator developed in recent years, which are insensitive to neutron and sensitive to gamma rays and respond quickness. The relationship of CeF 3 scintillation detector gamma rays sensitivity with the change of crystal thickness was measured. The CeF 3 scintillation detector is composed by high liner current photomultiplier tube of CHφT3, CHφT5 and CeF 3 scintillator. The detector gamma rays sensitivity of purple photocell and common photocell with CeF 3 scintillator were measured too

Identification of irradiated spices with luminescence measurements: a European intercomparison

Energy Technology Data Exchange (ETDEWEB)

Heide, L; Guggenberger, R; Boegl, K W [Federal Health Office, Neuherberg/Muenchen (Germany, F.R.). Inst. for Radiation Hygiene

1989-01-01

Blind tests were performed measuring the thermoluminescence intensity on samples from 10 different spices that were either irradiated or unirradiated. The chemiluminescence was measured on 10 additional spice samples. Twelve institutions participated in this collaborative study. Thresholds were defined which, when exceeded, declare samples as irradiated. The recovering rate was nearly 100% for samples investigated by thermoluminescence. Only one out of 495 irradiated samples was not identified. By using chemiluminescence, the participants succeeded in identifying 99% of unirradiated samples and 75% of irradiated samples from a total of 490 samples. (author).

Towards a Total Cross Section Measurement with the ALFA Detector at ATLAS

CERN Document Server

Trzebiński, Maciej

2013-01-01

The main goals of the Absolute Luminosity For ATLAS (ALFA) detector is to provide an absolute luminosity and total cross section measurement. The measurement method used, the detector alignment and the quality of the collected data are discussed.