Synthesis of plastic scintillation microspheres: Evaluation of scintillators

International Nuclear Information System (INIS)

Santiago, L.M.; Bagán, H.; Tarancón, A.; Garcia, J.F.

2013-01-01

The use of plastic scintillation microspheres (PSm) appear to be an alternative to liquid scintillation for the quantification of alpha and beta emitters because it does not generate mixed wastes after the measurement (organic and radioactive). In addition to routine radionuclide determinations, PSm can be used for further applications, e.g. for usage in a continuous monitoring equipment, for measurements of samples with a high salt concentration and for an extractive scintillation support which permits the separation, pre-concentration and measurement of the radionuclides without additional steps of elution and sample preparation. However, only a few manufacturers provide PSm, and the low number of regular suppliers reduces its availability and restricts the compositions and sizes available. In this article, a synthesis method based on the extraction/evaporation methodology has been developed and successfully used for the synthesis of plastic scintillation microspheres. Seven different compositions of plastic scintillation microspheres have been synthesised; PSm1 with polystyrene, PSm2 with 2,5-Diphenyloxazol(PPO), PSm3 with p-terphenyl (pT), PSm4 with PPO and 1,4-bis(5-phenyloxazol-2-yl) (POPOP), PSm5 pT and (1,4-bis [2-methylstyryl] benzene) (Bis-MSB), PSm6 with PPO, POPOP and naphthalene and PSm7 with pT, Bis-MSB and naphthalene. The synthesised plastic scintillation microspheres have been characterised in terms of their morphology, detection capabilities and alpha/beta separation capacity. The microspheres had a median diameter of approximately 130 μm. Maximum detection efficiency values were obtained for the PSm4 composition as follows 1.18% for 3 H, 51.2% for 14 C, 180.6% for 90 Sr/ 90 Y and 76.7% for 241 Am. Values of the SQP(E) parameter were approximately 790 for PSm4 and PSm5. These values show that the synthesised PSm exhibit good scintillation properties and that the spectra are at channel numbers higher than in commercial PSm. Finally, the addition

BC-454 boron-loaded plastic scintillator

International Nuclear Information System (INIS)

Bellian, J.G.

1984-01-01

Prototype samples of plastic scintillators containing up to 10% by weight of natural boron have been produced. The maximum size scintillators made to date are 28 mm dia. x 100 mm long. Rods containing up to 2% boron are now made routinely and work is progressing on higher concentrations. The plastics are clear and emit the same blue fluorescence as other common plastic scintillators. It is expected that rods up to 3'' dia. containing 5% boron will be produced during the next few months. BC-454 is particularly useful in neutron research, materials studies, some types of neutron dosimetry, and monitoring of medium to high energy neutrons in the presence of other types radiation. It combines attractive features that enhance its usefulness to the physics community

A new plastic scintillator with large Stokes shift

International Nuclear Information System (INIS)

Destruel, P.; Taufer, M.

1989-01-01

We have developed a new plastic scintillator with the novel characteristic of highly localized light emission; scintillation and wavelength shifting take place within a few tens of micrometers of the primary ionization. The new scintillator consists of a scintillating polymer base [polyvinyl toluene (PVT) or polystyrene (PS)] doped with a single wavelength shifter, 1-phenyl-3-mesityl-2-pyrazoline (PMP), which has an exceptionally large Stokes shift and therefore a comparatively small self-absorption of its emitted light. In other characteristics (e.g. scintillation efficiency and decay time) the performance of the new scintillator is similar to a good quality commercial plastic scintillator such as NE110. (orig.)

Plastic scintillators with {beta}-diketone Eu complexes for high ionizing radiation detection

Energy Technology Data Exchange (ETDEWEB)

Adadurov, A.F., E-mail: adadurov@isma.kharkov.ua [Institute for Scintillating Materials, NAN of Ukraine, Lenin Avenue 60, 61001 Kharkov (Ukraine); Zhmurin, P.N.; Lebedev, V.N.; Kovalenko, V.N. [Institute for Scintillating Materials, NAN of Ukraine, Lenin Avenue 60, 61001 Kharkov (Ukraine)

2011-10-15

Luminescent and scintillation properties of polystyrene-based plastic scintillators with {beta}-diketone Eu complexes are investigated. A scintillator with dibenzoylmethane Eu complex containing two phenyl groups demonstrates the maximum scintillating efficiency. It is shown that plastic scintillators efficiency is dramatically decreased if {beta}-diketone derivatives contain no phenyl groups as substituents. This fact can be explained by exciplex mechanism of energy transfer from a matrix to Eu complex. - Highlights: > Fluorescent properties of polystyrene scintillators with {beta}-diketone complexes of Eu were studied. > Scintillating efficiency is increased with the number of phenyl groups in Eu complex. > This is related to exciplex mechanism of energy transfer from a polymer matrix to Eu complex.

Plastic scintillators with β-diketone Eu complexes for high ionizing radiation detection

International Nuclear Information System (INIS)

Adadurov, A.F.; Zhmurin, P.N.; Lebedev, V.N.; Kovalenko, V.N.

2011-01-01

Luminescent and scintillation properties of polystyrene-based plastic scintillators with β-diketone Eu complexes are investigated. A scintillator with dibenzoylmethane Eu complex containing two phenyl groups demonstrates the maximum scintillating efficiency. It is shown that plastic scintillators efficiency is dramatically decreased if β-diketone derivatives contain no phenyl groups as substituents. This fact can be explained by exciplex mechanism of energy transfer from a matrix to Eu complex. - Highlights: → Fluorescent properties of polystyrene scintillators with β-diketone complexes of Eu were studied. → Scintillating efficiency is increased with the number of phenyl groups in Eu complex. → This is related to exciplex mechanism of energy transfer from a polymer matrix to Eu complex.

Neutron-gamma discrimination of boron loaded plastic scintillator

International Nuclear Information System (INIS)

Wang Dong; He Bin; Zhang Quanhu; Wu Chuangxin; Luo Zhonghui

2010-01-01

Boron loaded plastic scintillator could detect both fast neutrons thanks to hydrogen and thermal neutrons thanks to 10B. Both reactions have large cross sections, and results in high detection efficiency of incident neutrons. However, similar with other organic scintillators, boron loaded plastic scintillator is sensitive to gamma rays and neutrons. So gamma rays must be rejected from neutrons using their different behavior in the scintillator. In the present research zero crossing method was used to test neutron-gamma discrimination of BC454 boron loaded plastic scintillator. There are three Gaussian peaks in the time spectrum, they are corresponding to gamma rays, fast neutrons and flow neutrons respectively. Conclusion could be made that BC454 could clear discriminate slow neutrons and gamma, but the discrimination performance turns poor as the neutrons' energy becomes larger. (authors)

Technology update on fast plastic scintillators for medical applications

International Nuclear Information System (INIS)

Lyons, P.B.

1977-01-01

Plastic scintillators appear to have potential utility in three research areas related to nuclear medicine: (1) high count rate applications in general, (2) positron camera applications, and (3) positron source localization through measurement of relative arrival times of annihilation quanta at two co-linear detectors. These three areas of applicability depend on improvement in three specific areas of plastic scintillator technology: (a) development of plastics with very fast decay times, (b) development of plastics with greatly improved high energy photon detection efficiencies (high-Z loaded plastics), and (c) improvement of fast timing system capabilities. The three preceding areas of improvement are discussed

Radiation damage in plastic scintillators

International Nuclear Information System (INIS)

Majewski, S.

1990-01-01

Results of radiation damage studies in plastic scintillators are reviewed and critically analyzed from the point of view of applications of plastic scintillators in calorimetric detectors for the SSC. Damage to transmission and to fluorescent yield in different conditions is discussed. New directions in R ampersand D are outlined. Several examples are given of the most recent data on the new scintillating materials made with old and new plastics and fluors, which are exhibiting significantly improved radiation resistance. With a present rate of a vigorous R D programme, the survival limits in the vicinity of 100 MRad seem to be feasible within a couple of years

Comparison of plastic scintillating fibres and capillaries filled with liquid scintillator

International Nuclear Information System (INIS)

Cardini, A.; Cavasinni, V.; Girolamo, B. di; Flaminio, V.; Golovkin, S.V.; Gorin, A.M.; Kulichenko, A.V.; Kushnirenko, A.E.; Pyshev, A.I.; Manuilov, I.; Vasilchenko, V.G.

1994-01-01

A comparison is made between the light yield, attenuation length, time response and light propagation speed in plastic scintillating fibres (SCSF-38 and Kuraray-3HF) and quartz capillaries filled with liquid scintillator (LS) 1-methilnaphthalene (1MN) doped with new dyes R45 and R39. The inner diameter of capillaries and diameter of plastic fibres is 0.5 mm. The number of photoelectrons detected at the far end (2 m) was 2.9 for capillaries filled with 1MN+3 g/l R45 while it was 1.8 times smaller in the case of SCSF-38 and 3 times smaller in the case of Kuraray 3HF plastic fibres. Taking into account the quantum efficiency of the photodetector used these reduction factors became 3.0 and 2.0, respectively. Good attenuation length, high light output and also excellent radiation resistance of capillaries filled with LS (>60 Mrad, measured elsewhere) show that they are a very promising alternative to plastic scintillating fibres for future applications in tracking detectors and calorimeters. ((orig.))

Temperature dependence of plastic scintillators

Science.gov (United States)

Peralta, L.

2018-03-01

Plastic scintillator detectors have been studied as dosimeters, since they provide a cost-effective alternative to conventional ionization chambers. Several articles have reported undesired response dependencies on beam energy and temperature, which provides the motivation to determine appropriate correction factors. In this work, we studied the light yield temperature dependency of four plastic scintillators, BCF-10, BCF-60, BC-404, RP-200A and two clear fibers, BCF-98 and SK-80. Measurements were made using a 50 kVp X-ray beam to produce the scintillation and/or radioluminescence signal. The 0 to 40 °C temperature range was scanned for each scintillator, and temperature coefficients were obtained.

Response function measurement of plastic scintillator for high energy neutrons

International Nuclear Information System (INIS)

Sanami, Toshiya; Ban, Syuichi; Takahashi, Kazutoshi; Takada, Masashi

2003-01-01

The response function and detection efficiency of 2''φ x 2''L plastic (PilotU) and NE213 liquid (2''NE213) scintillators, which were used for the measurement of secondary neutrons from high energy electron induced reactions, were measured at Heavy Ion Medical Accelerator in Chiba (HIMAC). High energy neutrons were produced via 400 MeV/n C beam bombardment on a thick graphite target. The detectors were placed at 15 deg with respect to C beam axis, 5 m away from the target. As standard, a 5''φ x 5''L NE213 liquid scintillator (5''NE213) was also placed at same position. Neutron energy was determined by the time-of-flight method with the beam pickup scintillator in front of the target. In front of the detectors, veto scintillators were placed to remove charged particle events. All detector signals were corrected with list mode event by event. We deduce neutron spectrum for each detectors. The efficiency curves for pilotU and 2''NE213 were determined on the bases of 5 N E213 neutron spectrum and its efficiency calculated by CECIL code. (author)

Preparation and characterization of a novel UV-curable plastic scintillator

Energy Technology Data Exchange (ETDEWEB)

Zhu, Jun [Engineering Research Center of High Performance Polymer and Molding Technology, Ministry of Education, Qingdao University of Science and Technology, Qingdao 266042 (China); Joint Laboratory for Extreme Conditions Matter Properties, Southwest University of Science and Technology and Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621010 (China); Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); Ding, Yunyu [Engineering Research Center of High Performance Polymer and Molding Technology, Ministry of Education, Qingdao University of Science and Technology, Qingdao 266042 (China); Zhu, Jiayi [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); Qi, Di [Engineering Research Center of High Performance Polymer and Molding Technology, Ministry of Education, Qingdao University of Science and Technology, Qingdao 266042 (China); Su, Ming [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); Xu, Yewei; Bi, Yutie [Joint Laboratory for Extreme Conditions Matter Properties, Southwest University of Science and Technology and Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621010 (China); Lin, Runxiong, E-mail: qdlrx@qust.edu.cn [Engineering Research Center of High Performance Polymer and Molding Technology, Ministry of Education, Qingdao University of Science and Technology, Qingdao 266042 (China); Zhang, Lin, E-mail: zhlmy@sina.com [Joint Laboratory for Extreme Conditions Matter Properties, Southwest University of Science and Technology and Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621010 (China); Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China)

2016-05-01

A novel UV-curable plastic scintillator was first prepared by using the technology of photosensitivity rapid prototyping. It used the copolymer of 621A-80, TPGDA and styrene as the matrix doped with PPO and POPOP. Its fluorescence spectra displayed a maximum emission wavelength at 428 nm. The light yield of the plastic scintillator was approximately 7.1% of anthracene on the basis of a comparison with the commercially available scintillator (ST-401). The as-prepared plastic scintillator also displayed a fast scintillation decay. Its decay time is 2.6 ns approximately. Importantly, through the technology of photosensitivity rapid prototyping, the plastic scintillator could be prepared in a short period of time at low temperature. What's more, this preparation method provides the possibility of combining the plastic scintillator with 3D printing technology, and then the applications of the plastic scintillator may be expanded greatly.

Plastic use in technology of scintillation detector fabrication

International Nuclear Information System (INIS)

Mlika, V.

1977-01-01

The technique of plastic mandrel fabrication for scintillation detectors is developed. ''Forsan 548'' (thermopolimer of ABS type) and ''Krasten 127'' (polystyrene) are used. The mandrel is fabricated by the casting method under pressure with a subsequent parts adhesion. An adhesive substance is applied on the basis of polymerizing monomer of acrylate rotors and organic polysis cyanates. The developed construction consists totally of 5 components, only one of them being machined (lightquide). Testing under trying conditions (during 300 hours at the temperature from -30 deg to +50 deg C under the silicon oil layer or at the humidity up to 95% have shown high reliability of the construction. It is supposed, that the suggested technology will economize 3, 4 hours of turning lathe work for one mandrel and will reduce for 1-3 hours the scintillation mandrel frlming process

Water-equivalent plastic scintillation detectors for radiotherapy dosimetry

International Nuclear Information System (INIS)

Beddar, A.S.

1995-01-01

Plastic scintillation dosimetry is a promising new method of measuring absorbed dose for high energy radiotherapy beams. The theory behind this concept will be presented along with the many advantages that it offers over conventional dosimetry. A variety of plastic scintillation detector systems have been recently developed for photon and electron dosimetry. These new water-equivalent detectors use small to miniature plastic scintillators. Their attractive feature lies in their use for field mapping in water, particularly for small fields, high dose gradient regions, and near inhomogeneous interfaces, or for in-vivo insertions. The physical characteristics and the dosimetric properties of these scintillators will be presented, discussed, and compared to the commonly used detectors in radiation dosimetry. The system first used successfully for multi-purpose radiotherapy field mapping, as well as other systems, will be described. The technical challenges of the design of these detectors including the optical coupling to small fibers will be discussed. One of the limitations, at the present time, is the radiation-induced light produced in the optical fibers that are used to transmit the signal to the photodetectors. The mechanisms of these spurious effects will be identified and discussed with emphasis on signal-to-noise improvements

Radiation effects in polymers for plastic scintillation detectors

International Nuclear Information System (INIS)

Pla-Dalmau, A.; Bross, A.D.; Hurlbut, C.R.; Moser, S.W.

1994-01-01

Recent developments in both scintillating plastic optical fibers and photon detection devices have spawned new applications for plastic scintillator detectors. This renewed attention has encouraged research that addresses the radiation stability of plastic scintillators. The optical quality of the polymer degrades with exposure to ionizing radiation and thus the light yield of the detector decreases. A complete understanding of all the mechanisms contributing to this radiation-induced degradation of the polymer can lead to techniques that will extend the radiation stability of these materials. Various radiation damage studies have been performed under different atmospheres and dose rates. Currently, the use of additives to preserve the optical properties of the polymer matrix under radiation is being investigated. The authors discuss the effect of certain antioxidants, plasticizers, and cross-linking agents on the radiation resilience of plastic scintillators

Gammastic: towards a pseudo-gamma spectrometry in plastic scintillators

International Nuclear Information System (INIS)

Hamel, Matthieu; Dehe-Pittance, Chrystele; Coulon, Romain; Carrel, Frederick; Pillot, Philippe; Barat, Eric; Dautremer, Thomas; Montagu, Thierry; Normand, Stephane

2013-06-01

War against CBRN-E threats needs to continuously develop sensors with improved detection efficiency. More particularly, this topic concerns the NR controls for homeland security. A first analysis requires indeed a fast gamma spectrometry so as to detect potential special nuclear materials (SNM). To this aim, plastic scintillators could represent the best alternative for the production of large-scale, low-cost radiation portal monitors to be deployed on boarders, tolls, etc. Although they are known to be highly sensitive to gamma rays, due to their poor resolution, information relative to the nature of the SNM is tricky. Thus, only the Compton edge is obtained after interaction, and no information of the photoelectric peak is observed. This project concerns new developments on a possible pseudo-gamma spectrometry performed with plastic scintillators. This project is articulated on a combination of two developments: - The design of new materials most suitable for recovering the photoelectric peak after gamma interaction with the scintillator. This work concerns mainly plastic scintillators loading with heavy elements, such as lead or bismuth. - The analysis of the resulting signal with smart algorithms. This work is thus a pluri-disciplinary work performed at CEA LIST and embeds 4 main disciplines: MCNPX simulations (simulated spectra), chemistry of materials (preparation of various plastic scintillators with different properties), instrumentation (lab experiments) and smart algorithms. Really impressive results were obtained with the unfolding of simulated spectra at various energies (from 241 Am to 60 Co) and an innovative approach was proposed to counter-balance the quenching effect of luminescence by heavy elements in plastic scintillators. (authors)

Development of TOF-PET using Compton scattering by plastic scintillators

International Nuclear Information System (INIS)

Kuramoto, M.; Nakamori, T.; Kimura, S.; Gunji, S.; Takakura, M.; Kataoka, J.

2017-01-01

We propose a time-of-flight (TOF) technique using plastic scintillators which have fast decay time of a few ns for positron emission tomography (PET). While the photoelectric absorption probability of the plastic for 511 keV gamma rays are extremely low due to its small density and effective atomic number, the cross section of Compton scattering is comparable to that of absorption by conventional inorganic scintillators. We thus propose TOF-PET using Compton scattering with plastic scintillators (Compton-PET), and performed fundamental experiments towards exploration of the Compton-PET capability. We demonstrated that the plastic scintillators achieved the better time resolution in comparison to LYSO(Ce) and GAGG(Ce) scintillators. In addition we evaluated the depth-of-interaction resolving capability with the plastic scintillators.

Development of TOF-PET using Compton scattering by plastic scintillators

Energy Technology Data Exchange (ETDEWEB)

Kuramoto, M., E-mail: kuramoto@maxwell.kj.yamagata-u.ac.jp [Yamagata University, Kojirakawa 1-4-12, Yamagata 990-8560 (Japan); Nakamori, T., E-mail: nakamori@maxwell.kj.yamagata-u.ac.jp [Yamagata University, Kojirakawa 1-4-12, Yamagata 990-8560 (Japan); Kimura, S.; Gunji, S.; Takakura, M. [Yamagata University, Kojirakawa 1-4-12, Yamagata 990-8560 (Japan); Kataoka, J. [Waseda University, Okubo 3-4-1, Shinjuku, Tokyo 169-8555 (Japan)

2017-02-11

We propose a time-of-flight (TOF) technique using plastic scintillators which have fast decay time of a few ns for positron emission tomography (PET). While the photoelectric absorption probability of the plastic for 511 keV gamma rays are extremely low due to its small density and effective atomic number, the cross section of Compton scattering is comparable to that of absorption by conventional inorganic scintillators. We thus propose TOF-PET using Compton scattering with plastic scintillators (Compton-PET), and performed fundamental experiments towards exploration of the Compton-PET capability. We demonstrated that the plastic scintillators achieved the better time resolution in comparison to LYSO(Ce) and GAGG(Ce) scintillators. In addition we evaluated the depth-of-interaction resolving capability with the plastic scintillators.

Development of TOF-PET using Compton scattering by plastic scintillators

Science.gov (United States)

Kuramoto, M.; Nakamori, T.; Kimura, S.; Gunji, S.; Takakura, M.; Kataoka, J.

2017-02-01

We propose a time-of-flight (TOF) technique using plastic scintillators which have fast decay time of a few ns for positron emission tomography (PET). While the photoelectric absorption probability of the plastic for 511 keV gamma rays are extremely low due to its small density and effective atomic number, the cross section of Compton scattering is comparable to that of absorption by conventional inorganic scintillators. We thus propose TOF-PET using Compton scattering with plastic scintillators (Compton-PET), and performed fundamental experiments towards exploration of the Compton-PET capability. We demonstrated that the plastic scintillators achieved the better time resolution in comparison to LYSO(Ce) and GAGG(Ce) scintillators. In addition we evaluated the depth-of-interaction resolving capability with the plastic scintillators.

Development of radiophotometric dosemeters with high sensitivity using plastic scintillators as a light intensifier

International Nuclear Information System (INIS)

Mesquita, C.H. de; Hamada, M.M.

1987-01-01

Rectangular plates of plastic scintillators are developed and their effect as light converter evaluated, when used as film-holder in conventional photography dosemeters. In this dosemeter, the radiation that not interacts in the photographic film can be detected by light photons generation in the plastic scintillators, sensitizing the film. (C.G.C.) [pt

Plastic Scintillators for Pulse Shape Discrimination of Particle Types in Radiation Detection

Science.gov (United States)

Hajagos, Tibor Jacob

Organic scintillators have a long history in the field of radiation detection, dating back to some of the earliest studies of organic photophysics and optoelectronic properties. In particular, plastics have come to dominate the commercial market for organic scintillators, due to their low cost and ease of use and manufacturing, and more notably in spite of their poorer performance in many metrics. While there has been decades of active research since their inception, little progress has been made to improve upon the now well established compositions of commercial plastics, a notable exception being the recent development of plastic scintillators capable of pulse shape discrimination (PSD) of n/gamma radiation, which is of particular interest among governments and industry for the detection of illicit nuclear material and weapons. In recent years, much attention has been paid towards the study of luminescent organic materials, in particular due to the invention and widespread adoption of organic light emitting diode (OLED) based electronic devices, and the knowledge and lessons that have been fundamental to such fields have recently begun to be adopted by the organic scintilator community. In this work, new approaches to the design of both plastic scintillator components, and of the materials as a whole, are described, with particular emphasis paid towards the design and synthesis of small molecule scintillating dyes that are specifically tailored towards the development of PSD-capable plastic scintilators. In the first of these approaches, the design and synthesis of a highly soluble and polymerizable derivative of 9,10-diphenylanthracene is described, and the properties of plastic scintilators fabricated from this dye when copolymerized with poly(vinyl toluene) were investigated. This particular approach was used to demonstrate a proof-of-concept of PSD in highly loaded plastics stabilized through copolymerization of the primary dye, a strategy conceived to

The use of energy information in plastic scintillator materia

International Nuclear Information System (INIS)

Ely, J.; Anderson, K.; Bates, D.; Kouzes, R.; Lo Presti, C.; Runkle, R.; Siciliano, E.; Weier, D.

2008-01-01

Plastic scintillator material is often used for gamma-ray detection in many applications due to its relatively good sensitivity and cost-effectiveness compared to other detection materials. However, due to the dominant Compton scattering interaction mechanism, full energy peaks are not observed in plastic scintillator spectra and isotopic identification is impossible. Typically plastic scintillator detectors are solely gross count detectors. In some safeguards and security applications, such as radiation portal monitors for vehicle screening, naturally-occurring radioactive material (NORM) often triggers radiation alarms and results in innocent or nuisance alarms. The limited energy information from plastic scintillator material can be used to discriminate the NORM from targeted materials and reduce the nuisance alarm rate. An overview of the utilization of the energy information from plastic scintillator material will be presented, with emphasis on the detection capabilities and potential limitations for safeguards and security applications. (author)

Highly lead-loaded red plastic scintillators as an X-ray imaging system for the laser Mega Joule

International Nuclear Information System (INIS)

Hamel, Matthieu; Normand, Stephane; Turk, Gregory; Darbon, Stephane

2012-01-01

The scope of this project intends to record spatially resolved images of core shape and size of a deuterium-tritium micro-balloon during inertial confinement fusion (ICF) experiments at Laser Mega Joule facility (LMJ). We need to develop an x-ray imaging system which can operate in the hard radiative background generated by an ignition shot of ICF. The scintillator is a part of the imaging system and has to gather a compromise of scintillating properties (scintillating efficiency, decay time, emission wavelength) so as to both operate in the hard radiative environment and to allow the acquisition of spatially resolved images. Inorganic scintillators cannot be used because no compromise can be found regarding the expected scintillating properties. Most of them are not fast enough and emit blue light. Organic scintillators are generally fast, but present low x-ray photoelectric absorption in the 10 to 40 keV range. This does not enable the acquisition of spatially resolved images. To this aim, we have developed highly lead-loaded and red-fluorescent fast plastic scintillators. Such a combination is not currently available via scintillator suppliers, since they propose only blue-fluorescent plastic scintillators doped with up to 12 wt% Pb. Thus, incorporation ratio up to 27 wt% Pb has been reached in our laboratory, which can afford a plastic scintillator with an outstanding Z(eff) close to 50. X-rays in the 10 to 40 keV range can thus interact with a higher probability of photoelectric effect than for classic organic scintillators, such as NE-102. The strong orange-red fluorescence can be filtered, so that we can eliminate residual Cerenkov light, generated by gamma-ray absorption in glass parts of the imaging system. Characteristic decay times of our scintillators evaluated under UV excitation were estimated to be in the range 10 to 13 ns. (authors)

Accelerated Aging Test for Plastic Scintillator Gamma Ray Detectors

Energy Technology Data Exchange (ETDEWEB)

Kouzes, Richard T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2017-05-12

Polyvinyl toluene (PVT) and polystyrene (PS), collectively referred to as “plastic scintillator,” are synthetic polymer materials used to detect gamma radiation, and are commonly used in instrumentation. Recent studies have revealed that plastic scintillator undergoes an environmentally related material degradation that adversely affects performance under certain conditions and histories. A significant decrease in gamma ray sensitivity has been seen in some detectors in systems as they age. The degradation of sensitivity of plastic scintillator over time is due to a variety of factors, and the term “aging” is used to encompass all factors. Some plastic scintillator samples show no aging effects (no significant change in sensitivity over more than 10 years), while others show severe aging (significant change in sensitivity in less than 5 years). Aging effects arise from weather (variations in heat and humidity), chemical exposure, mechanical stress, light exposure, and loss of volatile components. The damage produced by these various causes can be cumulative, causing observable damage to increase over time. Damage may be reversible up to some point, but becomes permanent under some conditions. It has been demonstrated that exposure of plastic scintillator in an environmental chamber to 30 days of high temperature and humidity (90% relative humidity and 55°C) followed by a single cycle to cold temperature (-30°C) will produce severe fogging in all PVT samples. This thermal cycle will be referred to as the “Accelerated Aging Test.” This document describes the procedure for performing this Accelerated Aging Test.

Light pulse shapes from plastic scintillators

International Nuclear Information System (INIS)

Moszynski, M.; Bengtson, B.

1977-01-01

A detailed study of the light pulse shape from the binary NE 111 and the ternary Pilot U, Naton 136, KL 236, NE 102A, NE 104 and NE 110 plastic scintillators was performed by the single photon method using XP 1021 and C 31024 photomultipliers. The analysis of the shape of the light pulses determined experimentally for several samples of different dimensions gave the following conclusions. The original light pulse shape from the binary NE 111 scintillator, as measured with a 5 mm thick polished sample is described analytically by the convolution integral of a Gaussian and an exponential function. The Gaussian function may reflect a deexcitation of several higher levels of the solvent molecules excited by nuclear particles preceding an intermolecular energy transfer in the scintillator. It may introduce a rather important limitation of the speed of plastic scintillators as the standard deviation of the Gaussian function is equal to 0.2 ns. The light pulse shape from the ternary plastics is described by the convolution integral of a Gaussian and two exponential functions. The Gaussian function presents the rate of energy transfer from nuclear particles to the primary solute as in the binary plastics. The exponential functions describe the energy transfer from the primary solute to the wavelength shifter and the final emission of the light. (Auth.)

Coping with plastic scintillators in nuclear safeguards

International Nuclear Information System (INIS)

Fehlau, P.E.; Brunson, G.S.

1983-01-01

Plastic scintillators offer several advantages for nuclear safeguards research and technology to those who design, assemble, encapsulate, and calibrate detectors from raw materials that are commercially available. These large, inexpensive detectors have good spatial uniformity and good high-energy gamma-ray response. Uniform light collection is obtained with a light pipe attached to a polished scintillator wrapped with aluminum foil. Best low-energy response is obtained by applying a variance analyzer to select the low energy bias level

Transparent plastic scintillators for neutron detection based on lithium salicylate

International Nuclear Information System (INIS)

Mabe, Andrew N.; Glenn, Andrew M.; Carman, M. Leslie; Zaitseva, Natalia P.; Payne, Stephen A.

2016-01-01

Transparent plastic scintillators with pulse shape discrimination containing "6Li salicylate have been synthesized by bulk polymerization with a maximum "6Li loading of 0.40 wt%. Photoluminescence and scintillation responses to gamma-rays and neutrons are reported herein. Plastics containing "6Li salicylate exhibit higher light yields and permit a higher loading of "6Li as compared to previously reported plastics based on lithium 3-phenylsalicylate. However, pulse shape discrimination performance is reduced in lithium salicylate plastics due to the requirement of adding more nonaromatic monomers to the polymer matrix as compared to those based on lithium 3-phenylsalicylate. Reduction in light yield and pulse shape discrimination performance in lithium-loaded plastics as compared to pulse shape discrimination plastics without lithium is interpreted in terms of energy transfer interference by the aromatic lithium salts. - Highlights: • Plastic scintillator with 0.4% "6Li loading is reported using lithium salicylate. • Influence of lithium salts on the scintillation mechanism is explored. • New lithium-loaded scintillator provides improved light yield and reduced cost.

Gamma spectrometry and plastic-scintillator inherent background

International Nuclear Information System (INIS)

Pomerantsev, V.V.; Gagauz, I.B.; Mitsai, L.I.; Pilipenko, V.S.; Solomonov, V.M.; Chernikov, V.V.; Tsirlin, Y.A.

1988-01-01

The authors measured the energy resolution for a linear dependence of light yield on gamma radiation energy of gamma spectrometers based on plastic scintillation detectors for several plastic scintillators. If there were several gamma lines from the source the line with the highest energy was used to eliminate distortion due to overlap from the Compton background from gamma radiation of higher energy. Attenuation lengths were calculated. The tests were based on three modes of interaction between the gamma radiation and the scintillator: Compton scattering, the photoelectric effect, and pair formation. The contribution from light collection was also considered. The scintillators tested included polystyrene, polymethyl methacrylate, cesium iodide, and sodium iodide. Gamma sources included cesium 137, sodium 22, potassium 40, yttrium 88, thorium 232, and plutonium-beryllium

Plastic scintillator-based hodoscope for the characterization of large ...

Indian Academy of Sciences (India)

Plastic scintillator-based hodoscope for the characterization of large-area resistive plate chambers. V K S KASHYAP C YADAV ... Keywords. Plastic scintillators; resistive plate chambers. ... Pramana – Journal of Physics | News. © 2017 Indian ...

Production of the Large-area Plastic Scintillator for Beta-ray Detection using Epoxy Resin

International Nuclear Information System (INIS)

Nam, Jong Soo; Choi, Yong Seok; Hong, Sang Bum; Seo, Bum Kyung; Moon, Jei Kwon; Choi, Jong Won

2016-01-01

In this study, we prepared a plastic scintillator whose manufacturing process is simple and can be freely shaped. A thin plate of the plastic scintillator was manufactured using epoxy resin as a polymer. The plastic scintillator was made by mixing epoxy resin and organic scintillators under various conditions. The optimal mixture ratio to prepare the plastic scintillator was derived from the above results. Using the derived results, we made the large-area plastic scintillator which can quickly measure the contamination site and evaluated characteristics of the large-area plastic scintillator in the laboratory. A thin plate of a plastic scintillator with a simple preparation process can be freely shaped using epoxy resin and organic scintillators such as PPO and POPOP. PPO emits scintillation of light in the ultraviolet range, and POPOP is a wave shifter for moving the wavelength responsible for the PMT. The mixture ratio of PPO and POPOP was determined using their emission spectra. The optimal weight percentage of PPO and POPOP in an organic scintillator was determined to be 0.2 wt%:0.01 wt%. Based on the above results, the large-area plastic scintillator of the window size of a typical pancake-type αβ surface contamination counter was prepared. We want to evaluate the characteristics of the large-area plastic scintillator. However, there were the difficulties in evaluating characteristics of the large-area plastic scintillator. The cross-sectional area of the large-area plastic scintillator is significantly different to PMT

Production of the Large-area Plastic Scintillator for Beta-ray Detection using Epoxy Resin

Energy Technology Data Exchange (ETDEWEB)

Nam, Jong Soo; Choi, Yong Seok; Hong, Sang Bum; Seo, Bum Kyung; Moon, Jei Kwon; Choi, Jong Won [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-10-15

In this study, we prepared a plastic scintillator whose manufacturing process is simple and can be freely shaped. A thin plate of the plastic scintillator was manufactured using epoxy resin as a polymer. The plastic scintillator was made by mixing epoxy resin and organic scintillators under various conditions. The optimal mixture ratio to prepare the plastic scintillator was derived from the above results. Using the derived results, we made the large-area plastic scintillator which can quickly measure the contamination site and evaluated characteristics of the large-area plastic scintillator in the laboratory. A thin plate of a plastic scintillator with a simple preparation process can be freely shaped using epoxy resin and organic scintillators such as PPO and POPOP. PPO emits scintillation of light in the ultraviolet range, and POPOP is a wave shifter for moving the wavelength responsible for the PMT. The mixture ratio of PPO and POPOP was determined using their emission spectra. The optimal weight percentage of PPO and POPOP in an organic scintillator was determined to be 0.2 wt%:0.01 wt%. Based on the above results, the large-area plastic scintillator of the window size of a typical pancake-type αβ surface contamination counter was prepared. We want to evaluate the characteristics of the large-area plastic scintillator. However, there were the difficulties in evaluating characteristics of the large-area plastic scintillator. The cross-sectional area of the large-area plastic scintillator is significantly different to PMT.

Discrimination of Naturally Occurring Radioactive Material in Plastic Scintillator Material

International Nuclear Information System (INIS)

Ely, James H.; Kouzes, Richard T.; Geelhood, Bruce D.; Schweppe, John E.; Warner, Ray A.

2003-01-01

Plastic scintillator material is used in many applications for the detection of gamma-rays from radioactive material, primarily due to the sensitivity per unit cost compared to other detection materials. However, the resolution and lack of full-energy peaks in the plastic scintillator material prohibits detailed spectroscopy. Therefore, other materials such as doped sodium iodide are used for spectroscopic applications. The limited spectroscopic information can however be exploited in plastic scintillator materials to provide some discrimination. The discrimination between man-made and naturally occurring sources would be useful in reducing alarm screening for radiation detection applications which target man-made sources. The results of applying the limited energy information from plastic scintillator material for radiation portal monitors are discussed.

Advanced Large Area Plastic Scintillator Project (ALPS): Final Report

International Nuclear Information System (INIS)

Jordan, David V.; Reeder, Paul L.; Todd, Lindsay C.; Warren, Glen A.; McCormick, Kathleen R.; Stephens, Daniel L.; Geelhood, Bruce D.; Alzheimer, James M.; Crowell, Shannon L.; Sliger, William A.

2008-01-01

The advanced Large-Area Plastic Scintillator (ALPS) Project at Pacific Northwest National Laboratory investigated possible technological avenues for substantially advancing the state-of-the-art in gamma-ray detection via large-area plastic scintillators. The three predominant themes of these investigations comprised the following: * Maximizing light collection efficiency from a single large-area sheet of plastic scintillator, and optimizing hardware event trigger definition to retain detection efficiency while exploiting the power of coincidence to suppress single-PMT 'dark current' background; * Utilizing anti-Compton vetoing and supplementary spectral information from a co-located secondary, or 'Back' detector, to both (1) minimize Compton background in the low-energy portion of the 'Front' scintillator's pulse-height spectrum, and (2) sharpen the statistical accuracy of the front detector's low-energy response prediction as implemented in suitable energy-windowing algorithms; and * Investigating alternative materials to enhance the intrinsic gamma-ray detection efficiency of plastic-based sensors

Intrinsic Evaluation of n/γ Discrimination in Organic Plastic Scintillators

International Nuclear Information System (INIS)

Blanc, Pauline; Hamel, Matthieu; Rocha, Licinio; Normand, Stephane; Pansu, Robert; Gobert, Fabrice; Lampre, Isabelle

2013-06-01

This paper is devoted to characterizing plastic scintillators with neutron/gamma (n/γ) discrimination abilities and understanding experimentally the photophysical processes downstream. This experimental work is divided into two main studies, neutron sources irradiations and optical photoionization on a range of organic scintillators. The commercial liquid and plastic scintillators, respectively BC-501A from Bicron and EJ-200 from Eljen, are used as references in term of respectively extremely high [1] and poor n/γ discrimination efficiency, or more precisely Triplet-Triplet Annihilation rate probabilities after nuclear irradiations. We have characterized a range of organic plastic scintillators including one developed in our laboratory that shows good discrimination efficiency when compared to plastics that discriminate from literature. For that purpose we use the well known charge comparison as a pulse shape discrimination (PSD) method. We have also studied raw wave forms acquired after neutron irradiation before any kind of treatment was applied and managed to separate two light components, prompt and delayed, thus two particle families. We have demonstrated that by exciting with a 70 femto-seconds pulsed Laser at the femtosecond up to 50 μJ at 260 nm, photoionization was achieved for a range of organic scintillators by observing a delayed light emission in the time decay fluorescence when the Laser energy deposited in the materials was increased. This work is ongoing at CEA in collaboration with the nuclear measurement industry Canberra and the Laboratoire de Chimie Physique from Orsay University. (authors)

Advanced Large Area Plastic Scintillator Project (ALPS): Final Report

Energy Technology Data Exchange (ETDEWEB)

Jordan, David V.; Reeder, Paul L.; Todd, Lindsay C.; Warren, Glen A.; McCormick, Kathleen R.; Stephens, Daniel L.; Geelhood, Bruce D.; Alzheimer, James M.; Crowell, Shannon L.; Sliger, William A.

2008-02-05

The advanced Large-Area Plastic Scintillator (ALPS) Project at Pacific Northwest National Laboratory investigated possible technological avenues for substantially advancing the state-of-the-art in gamma-ray detection via large-area plastic scintillators. The three predominant themes of these investigations comprised the following: * Maximizing light collection efficiency from a single large-area sheet of plastic scintillator, and optimizing hardware event trigger definition to retain detection efficiency while exploiting the power of coincidence to suppress single-PMT "dark current" background; * Utilizing anti-Compton vetoing and supplementary spectral information from a co-located secondary, or "Back" detector, to both (1) minimize Compton background in the low-energy portion of the "Front" scintillator's pulse-height spectrum, and (2) sharpen the statistical accuracy of the front detector's low-energy response prediction as impelmented in suitable energy-windowing algorithms; and * Investigating alternative materials to enhance the intrinsic gamma-ray detection efficiency of plastic-based sensors.

Optimization of plastic scintillator thicknesses for online beta/gamma detection

Directory of Open Access Journals (Sweden)

Pourtangestani K.

2012-04-01

Full Text Available For efficient beta detection in a mixed beta gamma field, Monte Carlo simulation models have been built to optimize the thickness of a plastic scintillator, used in a whole body monitor. The simulation has been performed using the MCNP/X code for different thicknesses of plastic scintillator from 150 μm to 600 μm. The relationship between the thickness of the scintillator and the efficiency of the detector has been analyzed. For 150 μm thickness, an experimental investigation has been conducted with different beta sources at different positions on the scintillator and the counting efficiency of the unit has been measured. Evaluated data along with experimental ones have been discussed. A thickness of 300 μm to 500 μm has been found to be the optimum thickness for high efficiency beta detection in the presence of low energy gamma-rays.

Recent developments in plastic scintillators with pulse shape discrimination

Science.gov (United States)

Zaitseva, N. P.; Glenn, A. M.; Mabe, A. N.; Carman, M. L.; Hurlbut, C. R.; Inman, J. W.; Payne, S. A.

2018-05-01

The paper reports results of studies conducted to improve scintillation performance of plastic scintillators capable of neutron/gamma pulse-shape discrimination (PSD). Compositional modifications made with the polymer matrix improved physical stability, allowing for increased loads of the primary dye that, in combination with selected secondary dyes, provided enhanced PSD especially important for the lower energy ranges. Additional measurements were made with a newly-introduced PSD plastic EJ-276, that replaces the first commercially produced EJ-299. Comparative studies conducted with the new materials and EJ-309 liquids at large scale (up to 10 cm) show that current plastics may provide scintillation and PSD performance sufficient for the replacement of liquid scintillators. Comparison to stilbene single crystals compliments the information about the status of the solid-state materials recently developed for fast neutron detection applications.

Experimental research of plastic scintillation detector loaded 6Li neutron energy response

International Nuclear Information System (INIS)

Wang Lizong; Zhang Chuanfei; Peng Taiping; Guo Cun; Yang Hongqiong; Zhang Jianhua

2005-01-01

A new plastic scintillator, plastic scintillator loaded 6 Li, is brought forward and developed in this paper in order to increase low energy neutron sensitivity. Neutron sensitivity of several plastic scintillation detectors loaded 6 Li new developed in neutron energy range 0.2 MeV-5.0 MeV are calibrated by direct current at serial accelerator. Energy response curves of the detectors are obtained in this experiment. It is shown that this new plastic scintillation detector can increase low energy neutron sensitivity in experimental results. (authors)

Discrimination methods between neutron and gamma rays for boron loaded plastic scintillators

CERN Document Server

Normand, S; Haan, S; Louvel, M

2002-01-01

Boron loaded plastic scintillators exhibit interesting properties for neutron detection in nuclear waste management and especially in investigating the amount of fissile materials when enclosed in waste containers. Combining a high thermal neutron efficiency and a low mean neutron lifetime, they are suitable in neutron multiplicity counting. However, due to their high sensitivity to gamma rays, pulse shape discrimination methods need to be developed in order to optimize the passive neutron assay measurement. From the knowledge of their physical properties, it is possible to separate the three kinds of particles that have interacted in the boron loaded plastic scintillator (gamma, fast neutron and thermal neutron). For this purpose, we have developed and compared the two well known discrimination methods (zero crossing and charge comparison) applied for the first time to boron loaded plastic scintillator. The setup for the zero crossing discrimination method and the charge comparison methods is thoroughly expl...

Investigation on neutron/gamma discrimination phenomena in plastic scintillators

International Nuclear Information System (INIS)

Blanc, Pauline

2014-01-01

This PhD topic was born from misunderstandings and incomplete knowledge of the mechanism and relative effectiveness of neutron and gamma-ray (n/γ) discrimination between plastic scintillators compared to liquid scintillators. The shape of the light pulse these materials generate following interaction with an ionizing particle (predominantly recoil protons in the case of neutrons and electrons in the case of gamma-rays) is different in time in a way that depends on the detected particle (nature and energy). It is this fact that enables separation (PSD). The behavior in liquid scintillators has been extensively studied experimentally for practical applications. Only recently has it been shown that a weak separation can also be achieved using specially prepared plastics. The study of this system presents an open field and the understanding of both liquids and plastics with respect to their PSD properties is far from complete. This work is dedicated to exploring the fundamental photophysical phenomena at play in the generation of luminescence emission, following the interaction of ionizing radiation with organic scintillators. For this purpose, firstly a detailed literature review of the state-of-the-art has been conducted extending from 1960 to the present day. Secondly a complete characterization of the main scintillating materials has been conducted to define their fluorescence properties and the characteristics of their scintillation under irradiation. Thirdly a proton beam has been used to simulate recoil protons to quantify under controlled laboratory conditions their specific energy deposition in a plastic scintillator with PSD properties. The fourth part of this thesis is devoted to the study of PSD efficiency of scintillators as a function of their molecular structure. This investigation has led to a plastic scintillator prepared in our laboratory with good PSD properties and a patent submission. Finally, photophysical experiments were performed using a

Radiation hardness of plastic scintillators for the Tile Calorimeter of the ATLAS detector

CERN Document Server

Jivan, Harshna; The ATLAS collaboration

2014-01-01

The Tile Calorimeter of the ATLAS detector, is a hadronic calorimeter responsible for detecting hadrons as well as accommodating for the missing transverse energy that result from the p-p collisions within the LHC. Plastic scintillators form an integral component of this calorimeter due to their ability to undergo prompt fluorescence when exposed to ionising particles. The scintillators employed are specifically chosen for their properties of high optical transmission and fast rise and decay time which enables efficient data capture since fast signal pulses can be generated. The main draw-back of plastic scintillators however is their susceptibility to radiation damage. The damage caused by radiation exposure reduces the scintillation light yield and introduces an error into the time-of flight data acquired. During Run 1 of the LHC data taking period, plastic scintillators employed within the GAP region between the Tile Calorimeter’s central and extended barrels sustained a significant amount of damage. Wit...

Cosmic ray spectroscopy using plastic scintillator detector

International Nuclear Information System (INIS)

Rudra, Sharmili; Nandan, Akhilesh P.; Neog, Himangshu; Biswas, S.; Mohanty, B.; Mahapatra, S.; Samal, P.K.

2014-01-01

A simple and new technique has been developed using plastic scintillator detectors for cosmic ray spectroscopy without single channel analyzer (SCA) or multichannel analyzer (MCA). In this technique only a leading edge discriminator (LED) and a NIM scaler have been used. Plastic scintillator detectors has been used to measure the velocity of cosmic ray muons. Here the time difference has been measured from the Tektronix DPO 5054 digital phosphor oscilloscope with 500 MHz and 5 GS/s. The details of experimental technique, analysis procedure and experimental results are presented

Optimum plastic scintillator and optical fiber combination for brachytherapy dosimetry

International Nuclear Information System (INIS)

Arnfield, Mark R.; Gaballa, Hani E.; Zwicker, Robert D.; Islam, Quazi; Schmidt-Ullrich, Rupert

1995-01-01

Purpose/Objective: There have been several recent reports using plastic scintillators to measure dose in photon and electron beams. External beam measurements agreed well with standard ion chamber dosimetry. This was implemented by using two identical, parallel optical fibers with a small piece of plastic scintillator attached to one. We have constructed a similar device for application to brachytherapy. Brachytherapy dosimetry is a more difficult problem than external beam because of high dose gradients and widely ranging photon energies. Based on detailed spectral measurements, we have designed a dosimeter specifically to meet the unique, stringent needs of brachytherapy. Materials and Methods: The work consisted of two stages. In the first stage, we measured the optical spectra emitted by commercial plastic scintillators and silica core optical fibers in the presence of a 10 Curie iridium 192 HDR source. In the second stage, the spectral information was used to select an optimum combination of scintillator and fiber which were incorporated in the dosimeter. Equipment for the spectral measurements included a 0.1 meter monochromator with a sensitive photomultiplier (PMT) with flat response across the visible. The resolution of spectral scans was 4 nm. The dosimeter was constructed with a 1mm x 3mm piece of plastic scintillator bonded with optical cement to a 0.6 mm diameter silica core optical fiber. A second, identical optical fiber running alongside the first, with no scintillator attached, was used for background subtraction. Two PMTs with high sensitivity in the visible were used at the fiber distal ends. There was a space for an optical filter between the fiber and the PMTs, whose purpose is described below. The PMTs were connected to a differential pair whose output was transferred to a current source for measurement by a standard electrometer. Results: The scintillation spectra of six different types of silica core optical fibers in the presence of the

Plastic scintillators based on polymers with eliminated excimer forming

Energy Technology Data Exchange (ETDEWEB)

Adadurov, A.F., E-mail: adadurov@isma.kharkov.u [Institute for Scintillating Materials NAN of Ukraine, 60 Lenin Ave, 61001 Kharkov (Ukraine); Yelyseev, D.A.; Titskaya, V.D.; Lebedev, V.N.; Zhmurin, P.N. [Institute for Scintillating Materials NAN of Ukraine, 60 Lenin Ave, 61001 Kharkov (Ukraine)

2011-05-15

Plastic scintillators (PS) were made based on benzyl methacrylate and methyl-methacrylate P(BzMA + MMA) copolymer in which the excimer forming rate is by two order lesser than that in polystyrene-based polymer matrix. Studying of these PS light yield demonstrates the importance of migration processes comparing to excimer formation. It is found that to obtain PS with high scintillation efficiency it is necessary to use the polymer base (matrix) in which excimer forming is eliminated but the migration process along the chromophores is maximally favored. To explain the accelerated energy transfer between phenyl chromophores it is proposed to use a mechanism of exchange of that virtual excitons that can propagate along a one-dimensional back-bone of polymer molecule. Clearing the details of mechanism of interaction between chromophores of polymer molecules which is responsible for accelerated radiationless energy transfer enable will determine in future the way of effective plastic scintillators designing.

Characteristics of plastic scintillators fabricated by a polymerization reaction

Energy Technology Data Exchange (ETDEWEB)

Lee, Cheol Ho; Son, Jaebum; Kim, Tae Hoon; Kim, Yong Kyun [Dept. of Nuclear Engineering, Hanyang University, Seoul (Korea, Republic of)

2017-04-15

Three plastic scintillators of 4.5 cm diameter and 2.5-cm length were fabricated for comparison with commercial plastic scintillators using polymerization of the styrene monomer 2.5-diphenyloxazole (PPO) and 1,4-bis benzene (POPOP). Their maximum emission wavelengths were determined at 426.06 nm, 426.06 nm, and 425.00 nm with a standard error of 0.2% using a Varian spectrophotometer (Agilent, Santa Clara, CA, USA). Compton edge spectra were measured using three gamma ray sources [i.e., cesium 137 ({sup 137}Cs), sodium 22 ({sup 22}Na), and cobalt 60 ({sup 60}Co)]. Energy was calibrated by analyzing the Compton edge spectra. The fabricated scintillators possessed more than 99.7% energy linearity. Light output was comparable to that of the BC-408 scintillator (Saint-Gobain, Paris, France). The fabricated scintillators showed a light output of approximately 59–64% of that of the BC-408 scintillator.

Methods for the continuous production of plastic scintillator materials

Science.gov (United States)

Bross, Alan; Pla-Dalmau, Anna; Mellott, Kerry

1999-10-19

Methods for producing plastic scintillating material employing either two major steps (tumble-mix) or a single major step (inline-coloring or inline-doping). Using the two step method, the polymer pellets are mixed with silicone oil, and the mixture is then tumble mixed with the dopants necessary to yield the proper response from the scintillator material. The mixture is then placed in a compounder and compounded in an inert gas atmosphere. The resultant scintillator material is then extruded and pelletized or formed. When only a single step is employed, the polymer pellets and dopants are metered into an inline-coloring extruding system. The mixture is then processed under a inert gas atmosphere, usually argon or nitrogen, to form plastic scintillator material in the form of either scintillator pellets, for subsequent processing, or as material in the direct formation of the final scintillator shape or form.

Sub-keV x-ray calibration of plastic scintillators

International Nuclear Information System (INIS)

Lyons, P.B.; Day, R.H.; Lier, D.W.; Elsberry, T.L.

1976-01-01

Several types of x-ray detectors have found widespread use for plasma diagnostic applications in the energy range below a few keV. Silicon diodes, photoelectric diodes, and plastic scintillators have been used to obtain diagnostic information in this region. Sub-keV calibration data for plastic scintillator detectors are reported, and the advantages and limitations of these three detectors in diagnostic measurements are compared. In a previous paper calibration data for plastic scintillators from 1.5 to 20 keV were given. In this paper the data are extended to the C-K/sub α/ line (277 eV). These data represent one application of a new sub-keV x-ray calibration facility at the Los Alamos Scientific Laboratory

Measurements of the electron dose distribution near inhomogeneities using a plastic scintillation detector

International Nuclear Information System (INIS)

Wells, C.M.M.; Mackie, T.R.; Podgorsak, M.B.; Holmes, M.A.; Papanikolaou, N.; Reckwerdt, P.J.; Cygler, J.; Rogers, D.W.O.; Bielajew, A.F.; Schmidt, D.G.

1994-01-01

Accurate measurement of the electron dose distribution near an inhomogeneity is difficult with traditional dosimeters which themselves perturb the electron field. The authors tested the performance of a new high resolution, water-equivalent plastic scintillation detector which has ideal properties for this application. A plastic scintillation detector with a 1 mm diameter, 3 mm long cylindrical sensitive volume was used to measure the dose distributions behind standard benchmark inhomogeneities in water phantoms. The plastic scintillator material is more water equivalent than polystyrene in terms of its mass collision stopping power and mass scattering power. Measurements were performed for beams of electrons having initial energies of 6 and 18 MeV at depths from 0.2-4.2 cm behind the inhomogeneities. The detector reveals hot and cold spots behind heterogeneities at resolutions equivalent to typical film digitizer spot sizes. Plots of the dose distributions behind air, aluminum, lead, and formulations for cortical and inner bone-equivalent materials are presented. The plastic scintillation detector is suited for measuring the electron dose distribution near an inhomogeneity. 14 refs., 9 figs

The primary research for the development of the plastic scintillator

International Nuclear Information System (INIS)

Huang Bing; Li Wei; Yang Yan

2014-01-01

In this study, We adopted the theory of the polymerism to synthesize the scintillator, and we composed the scintillating material (2, 5-diphenyloxazole (PPO) and 1, 4-bis-(2-(5-phenyloxazolyl))-benzene (POPOP)) to the plastic (PMMA) successfully by the polymerization. We found that the scintillating material (PPO and POPOP) spread well into the plastic and the scintillator could be well seasoned with many different environmental condition through the spectroanalysis and the mechanical testing. We also found that the scintillator was well responded to the γ-ray testing which we did. According to the increase of the content for the PPO, the radiant efficiency of the γ-ray testing was increase too. (authors)

Study and understanding of n/γ discrimination processes in organic plastic scintillators

International Nuclear Information System (INIS)

Hamel, Matthieu; Blanc, Pauline; Rocha, Licinio; Normand, Stephane; Pansu, Robert

2013-01-01

For 50 years, it was assumed that unlike liquid scintillators or organic crystals, plastic scintillators were not able to discriminate fast neutrons from gamma. In this work, we will demonstrate that triplet-triplet annihilations (which are responsible of n/γ discrimination) can occur even in plastic scintillators, following certain conditions. Thus, the presentation will deal with the chemical preparation, the characterization and the comparison of n/γ pulse shape discrimination of various plastic scintillators. To this aim, scale-up of the process allowed us to prepare a O 100 mm x*110 mm thick. (authors)

Factors determining radiation stability of plastic scintillators

Energy Technology Data Exchange (ETDEWEB)

Barashkov, N.N. [Texas Univ., Richardson, TX (United States). Dept. of Chemistry; Gunder, O.A.; Voronkina, N.I. [National Ukrainian Academy of Science, Kharkov (Ukraine). Inst. for Single Crystals; Milinchuk, V.K. [Karpov Inst. of Physical Chemistry, Moscow (Russian Federation)

1996-11-01

Polystyrene (PS) and polyvinylxylene (PVX) are the base materials for plastic scintillators u.v.-Vis spectrophotometry, luminescence and ESR spectroscopy were performed on irradiated samples of PS and PVX with the p-terphenyl (TP) as the primary luminophore and 1,4-di-2(5-phenyloxazolyl-1,3) benzene (POPOP) as the secondary one. Dependence of the radioluminescence intensity of the scintillators on the concentration of the macroradicals formed by irradiation was investigated. Dose dependence of the radiation stability of scintillators is discussed. (author).

Factors determining radiation stability of plastic scintillators

International Nuclear Information System (INIS)

Barashkov, N.N.

1996-01-01

Polystyrene (PS) and polyvinylxylene (PVX) are the base materials for plastic scintillators u.v.-Vis spectrophotometry, luminescence and ESR spectroscopy were performed on irradiated samples of PS and PVX with the p-terphenyl (TP) as the primary luminophore and 1,4-di-2(5-phenyloxazolyl-1,3) benzene (POPOP) as the secondary one. Dependence of the radioluminescence intensity of the scintillators on the concentration of the macroradicals formed by irradiation was investigated. Dose dependence of the radiation stability of scintillators is discussed. (author)

Ionization and scintillation response of high-pressure xenon gas to alpha particles

International Nuclear Information System (INIS)

Álvarez, V; Cárcel, S; Cervera, A; Díaz, J; Ferrario, P; Gil, A; Gómez-Cadenas, J J; Borges, F I G; Conde, C A N; Fernandes, L M P; Freitas, E D C; Cebrián, S; Dafni, T; Gómez, H; Egorov, M; Gehman, V M; Goldschmidt, A; Esteve, R; Evtoukhovitch, P; Ferreira, A L

2013-01-01

High-pressure xenon gas is an attractive detection medium for a variety of applications in fundamental and applied physics. In this paper we study the ionization and scintillation detection properties of xenon gas at 10 bar pressure. For this purpose, we use a source of alpha particles in the NEXT-DEMO time projection chamber, the large scale prototype of the NEXT-100 neutrinoless double beta decay experiment, in three different drift electric field configurations. We measure the ionization electron drift velocity and longitudinal diffusion, and compare our results to expectations based on available electron scattering cross sections on pure xenon. In addition, two types of measurements addressing the connection between the ionization and scintillation yields are performed. On the one hand we observe, for the first time in xenon gas, large event-by-event correlated fluctuations between the ionization and scintillation signals, similar to that already observed in liquid xenon. On the other hand, we study the field dependence of the average scintillation and ionization yields. Both types of measurements may shed light on the mechanism of electron-ion recombination in xenon gas for highly-ionizing particles. Finally, by comparing the response of alpha particles and electrons in NEXT-DEMO, we find no evidence for quenching of the primary scintillation light produced by alpha particles in the xenon gas.

Factors determining radiation stability of plastic scintillators

Energy Technology Data Exchange (ETDEWEB)

Gunder, O.A.; Voronkina, N.I. [National Ukranian Academy of Science, Kharkov (Ukraine). Inst. for Single Crystals; Barashkov, N.N.; Milinchuk, V.K.; Jdanov, G.S. [Karpov Inst. of Physical Chemistry, Moscow (Russian Federation)

1995-07-01

Polystyrene (PS) and polyvinylxylene (PVX) are the base materials for plastic scintillators. UV-Vis spectrophotometry, luminescence and EPR spectroscopy were performed on irradiated samples of PS and PVX with the p-terphenyl (TP) as primary luminophore and 1,4-di-2(5-phenyloxazolyl-1,3)benzene (POPOP) as secondary one. Dependence of the radioluminescence intensity of the scintillators on the concentration of the macroradicals formed in them in the process of irradiation was investigated. Dose dependence of the radiation stability of scintillators is discussed. (Author).

Factors determining radiation stability of plastic scintillators

Science.gov (United States)

Gunder, O. A.; Voronkina, N. I.; Barashkov, N. N.; Milinchuk, V. K.; Jdanov, G. S.

1995-07-01

Polystyrene (PS) and polyvinylxylene (PVX) are the base materials for plastic scintillators. UV-Vis spectrophotometry, luminescence and EPR spectroscopy were performed on irradiated samples of PS and PVX with the p-terphenyl (TP) as primary luminophore and 1,4-di-2(5-phenyloxazolyl-1,3)benzene (POPOP) as secondary one. Dependence of the radioluminescence intensity of the scintillators on the concentration of the macroradicals formed in them in the process of irradiation was investigated. Dose dependence of the radiation stability of scintillators is discussed.

Factors determining radiation stability of plastic scintillators

International Nuclear Information System (INIS)

Gunder, O.A.; Voronkina, N.I.

1995-01-01

Polystyrene (PS) and polyvinylxylene (PVX) are the base materials for plastic scintillators. UV-Vis spectrophotometry, luminescence and EPR spectroscopy were performed on irradiated samples of PS and PVX with the p-terphenyl (TP) as primary luminophore and 1,4-di-2(5-phenyloxazolyl-1,3)benzene (POPOP) as secondary one. Dependence of the radioluminescence intensity of the scintillators on the concentration of the macroradicals formed in them in the process of irradiation was investigated. Dose dependence of the radiation stability of scintillators is discussed. (Author)

Tests of a Fast Plastic Scintillator for High-Precision Half-Life Measurements

Science.gov (United States)

Laffoley, A. T.; Dunlop, R.; Finlay, P.; Leach, K. G.; Michetti-Wilson, J.; Rand, E. T.; Svensson, C. E.; Grinyer, G. F.; Thomas, J. C.; Ball, G.; Garnsworthy, A. B.; Hackman, G.; Orce, J. N.; Triambak, S.; Williams, S. J.; Andreoiu, C.; Cross, D.

2013-03-01

A fast plastic scintillator detector is evaluated for possible use in an ongoing program of high-precision half-life measurements of short lived β emitters. Using data taken at TRI-UMF's Isotope Separator and Accelerator Facility with a radioactive 26Na beam, a detailed investigation of potential systematic effects with this new detector setup is being performed. The technique will then be applied to other β-decay half-life measurements including the superallowed Fermi β emitters 10C, 14O, and T = 1/2 decay of 15O.

Calculation of efficiency of high-energy neutron detection by plastic scintillators

International Nuclear Information System (INIS)

Telegin, Yu.N.

1977-01-01

A computer was used to calculate neutron (5-30O MeV) registration effeciencies with plastic scintillators 2,5,10, 20,30,40 and 50 cm thick. The results are shown in the form of tables. The contributions to efficiency of various processes have been analysed. The calculation results may be used in planning experiments with neutron counters

Final LDRD report : advanced plastic scintillators for neutron detection.

Energy Technology Data Exchange (ETDEWEB)

Vance, Andrew L.; Mascarenhas, Nicholas; O' Bryan, Greg; Mrowka, Stanley

2010-09-01

This report summarizes the results of a one-year, feasibility-scale LDRD project that was conducted with the goal of developing new plastic scintillators capable of pulse shape discrimination (PSD) for neutron detection. Copolymers composed of matrix materials such as poly(methyl methacrylate) (PMMA) and blocks containing trans-stilbene (tSB) as the scintillator component were prepared and tested for gamma/neutron response. Block copolymer synthesis utilizing tSBMA proved unsuccessful so random copolymers containing up to 30% tSB were prepared. These copolymers were found to function as scintillators upon exposure to gamma radiation; however, they did not exhibit PSD when exposed to a neutron source. This project, while falling short of its ultimate goal, demonstrated the possible utility of single-component, undoped plastics as scintillators for applications that do not require PSD.

Development of radiophotometric dosemeters of high sensitivity using plastic scintillators as light intensifiers

International Nuclear Information System (INIS)

Mesquita, C.H. de; Hamada, M.M.

1987-01-01

The use of rectangular plates of plastic scintillators as film holders in conventional photographic dosemeters is reported. The efficiency of their use as light converters for increase the sensitivity of these dosemeters are studied. (M.A.C.) [pt

Detector of reactor antineutrinos with plastic scintillation bars

International Nuclear Information System (INIS)

Georgadze, A.Sh.; Pavlovich, V.M.

2015-01-01

Project of a segmented antineutrino detector is developed with the use of plastic scintillator rectangular bars 10 x 10 x 100 cm, wrapped in Gd foils and assembled to an array of 1 m3 active volume. The scintillation array is sandwiched at both sides by the continuous light guides of 100 x 100 x 10 cm size, from which the scintillation light is spreading simultaneously through continuous light guides between all photomultipliers, forming the specific Light Response Function (LRF), which is character to a certain nuclear event in detector. Analysis of LRF allows one effectively reject background events, providing high efficiency detection of antineutrino capture in the detector. Monte Carlo simulations with the help of MCNP and ZEMAX software show that with the use of selection criteria the neutrino events are well separated from the background

Optimization of the fabrication methodology for plastic scintillators using chemical catalyzers

International Nuclear Information System (INIS)

Costa Junior, Nelson P.; Costa, Fabio E. da; Mesquita, Carlos H.; Hamada, Margarida M.

1997-01-01

Plastic scintillator detectors were developed by polymerisation in the PPO and POPOP solution in styrene monomer, using catalyst 1-1 Bis(terc-peroxybuthyl)cyclohexane ranging from 0.008 to 0.5%. In order to study the catalyst influence on the plastic scintillator quality, the luminescence emission, transmittance, decay constant and light output for alpha and gamma rays were evaluated. For comparison, the same evaluation measurements were carried out using the plastic scintillator detector produced by thermal polymerisation under vacuum (1.0 x 10 -2 mbar), without catalyst. The results indicated that the catalyst concentration must range from 0.008 to 0.1%. (author). 10 refs., 7 figs., 1 tab

Plastic scintillators utilization in position sensitive detection systems

International Nuclear Information System (INIS)

Garcia, Marcelo Bernardes; Soares, Adalberto Jose; Baptista Filho, Benedito Dias

2002-01-01

This paper shows the viability of using a plastic scintillator detector to determine the one dimension position of a radioactive source. The experiments were performed using collimated 99m Tc sources of several activities supplied by the Centro de Radiofarmacia (from IPEN), and a 15 cm long plastic scintillator with diameter 5,08 cm, produced by the Centro de Tecnologia das Radiacoes (also from IPEN). The spectrum was obtained using the Genie 2000 software, and the results processed using a neural network specially developed for the proposed application. The final results demonstrate the viability of the proposed application. (author)

Optimization of the wavelength shifter ratio in a polystyrene based plastic scintillator through energy spectrum analysis

Energy Technology Data Exchange (ETDEWEB)

Kim, Ye Won; Kim, Myung Soo; Yoo, Hyun Jun; Lee, Dae Hee; Cho, Gyu Seong [Dept. of Nuclear and Quantum Engineering, KAIST, Daejeon (Korea, Republic of); Moon, Myung Kook [Neutron Instrumentation Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2017-02-15

The scintillation efficiency of the polystyrene based plastic scintillator depends on the ratio of the wavelength shifters, organic fluors (PPO and POPOP). Thus, 24 samples of the plastic scintillator were fabricated in order to find out the optimum ratio of the wavelength shifters in the plastic scintillator. The fabricated plastic scintillators were trimmed through a cutting and polishing process. They were used in gamma energy spectrum measurement with the {sup 137}Cs emitting monoenergy photon with 662 keV for the comparison of the scintillation efficiency. As a result, it was found out that the scintillator sample with 1.00 g of PPO (2,5-Diphenyloxazole) and 0.50 g of POPOP (1,4-Bis(5-phnyl-2oxidazolyl)benzene) dissolved in 100 g of styrene solution has the optimum ratio in terms of the light yield of the polystyrene based plastic scintillator.

Measurement of the plastic scintillator response to heavy ions, between 0 to 30 MeV/N

International Nuclear Information System (INIS)

Dorion, I.

1984-01-01

The light produced in a plastic scintillator depends on particle nature and energy. Theoretical models predict a linear behavior of the light output response for high energy heavy ions. An experimental set-up was realised in order to perform the integral and, in some case, the differential measurement of the light yield in a plastic scintillator (NE102) stopping 6 Li, 12 C, 16 O, 20 Ne, 40 Ar ions given by SARA, with particle incident energy from 3 to 30 MeV per nucleon. The plastic resolution was also measured. The data analysis leads to experimental results which are in good agreement with the predictions. Taking into account resolution value, the use of plastic scintillator in detection system allows in some case, particle identification [fr

High-efficiency organic glass scintillators

Science.gov (United States)

Feng, Patrick L.; Carlson, Joseph S.

2017-12-19

A new family of neutron/gamma discriminating scintillators is disclosed that comprises stable organic glasses that may be melt-cast into transparent monoliths. These materials have been shown to provide light yields greater than solution-grown trans-stilbene crystals and efficient PSD capabilities when combined with 0.01 to 0.05% by weight of the total composition of a wavelength-shifting fluorophore. Photoluminescence measurements reveal fluorescence quantum yields that are 2 to 5 times greater than conventional plastic or liquid scintillator matrices, which accounts for the superior light yield of these glasses. The unique combination of high scintillation light-yields, efficient neutron/gamma PSD, and straightforward scale-up via melt-casting distinguishes the developed organic glasses from existing scintillators.

Clinical dosimetry with plastic scintillators - Almost energy independent, direct absorbed dose reading with high resolution

Energy Technology Data Exchange (ETDEWEB)

Quast, U; Fluehs, D [Department of Radiotherapy, Essen (Germany). Div. of Clinical Radiation Physics; Fluehs, D; Kolanoski, H [Dortmund Univ. (Germany). Inst. fuer Physik

1996-08-01

Clinical dosimetry is still far behind the goal to measure any spatial or temporal distribution of absorbed dose fast and precise without disturbing the physical situation by the dosimetry procedure. NE 102A plastic scintillators overcome this border. These tissue substituting dosemeter probes open a wide range of new clinical applications of dosimetry. This versatile new dosimetry system enables fast measurement of the absorbed dose to water in water also in regions with a steep dose gradient, close to interfaces, or in partly shielded regions. It allows direct reading dosimetry in the energy range of all clinically used external photon and electron beams, or around all branchytherapy sources. Thin detector arrays permit fast and high resolution measurements in quality assurance, such as in-vivo dosimetry or even afterloading dose monitoring. A main field of application is the dosimetric treatment planning, the individual optimization of brachytherapy applicators. Thus, plastic scintillator dosemeters cover optimally all difficult fields of clinical dosimetry. An overview about its characteristics and applications is given here. 20 refs, 1 fig.

Is the holy grail plastic? Radiation identification from plastic scintillators

International Nuclear Information System (INIS)

Butchins, L. J. C.; Gosling, J. M.; Hogbin, M. R. W.; Jones, D. C.; Lacey, R. J.; Stearn, J. G.

2009-01-01

by plastic scintillator detectors to be increased by as much as 80% and for high energy industrial radionuclides to be identified with accuracy approaching 100%

High-pressure 3He gas scintillation neutron spectrometer

International Nuclear Information System (INIS)

Derzon, M.S.; Slaughter, D.R.; Prussin, S.G.

1985-10-01

A high-pressure, 3 He-Xe gas scintillation spectrometer has been developed for neutron spectroscopy on D-D fusion plasmas. The spectrometer exhibits an energy resolution of (121 +- 20 keV) keV (FWHM) at 2.5 MeV and an efficiency of (1.9 +- 0.4) x 10 -3 (n/cm 2 ) -1 . The contribution to the resolution (FWHM) from counting statistics is only (22 +- 3 keV) and the remainder is due predominantly to the variation of light collection efficiency with location of neutron events within the active volume of the detector

High pressure gas scintillation drift chambers with wave-shifter fiber readout

International Nuclear Information System (INIS)

Parsons, A.; Edberg, T.K.; Sadoulet, B.; Weiss, S.; Wilkerson, J.; Hurley, K.; Lin, R.P.

1990-01-01

The authors present results from a prototype high pressure xenon gas scintillation drift chamber using a novel wave-shifter fiber readout scheme. They have measured the primary scintillation light yield to be one photon per 76 ± 12 eV deposited energy. They present initial results of our chamber for the two-interaction separation (< 4 mm in the drift direction, ∼ 7 mm orthogonal to the drift); for the position resolution (< 400 μm rms in the plane orthogonal to the drift direction); and for the energy resolution (ΔE/E < 6% FWHM at 122 keV)

The impact of fluorescent dyes on the performances of polystyrene-based plastic scintillators

International Nuclear Information System (INIS)

Zhu, Jun; Deng, Cheng; Jiang, Huimin; Zheng, Zhanlong; Gong, Rui; Bi, Yutie; Zhang, Lin; Lin, Runxiong

2016-01-01

To investigate the influence of both the first luminescent additive and the wavelength-shifter on the performance of plastic scintillator, a series of polystyrene-based scintillator had been prepared by thermal polymerization. Three first luminescent additives (PPO, p-TP and b-PBD) and four wavelength-shifters (POPOP, Bis-MSB, Me-MSB and DPA) were added to the scintillators respectively. The comparison results showed that PPO and POPOP were the most adequate fluorescent dyes for the polystyrene-based plastic scintillator. Moreover, with the increase of the concentration of PPO and POPOP, the fluorescence intensity and light yield were increased firstly and then decreased. The plastic scintillator containing 2% PPO and 0.02% POPOP had the highest fluorescence intensity and light yield.

The impact of fluorescent dyes on the performances of polystyrene-based plastic scintillators

Energy Technology Data Exchange (ETDEWEB)

Zhu, Jun [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); Engineering Research Center of High Performance Polymer and Molding Technology, Ministry of Education, Qingdao University of Science and Technology, Qingdao 266042 (China); Joint Laboratory for Extreme Conditions Matter Properties, Southwest University of Science and Technology and Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621010 (China); Deng, Cheng; Jiang, Huimin [Engineering Research Center of High Performance Polymer and Molding Technology, Ministry of Education, Qingdao University of Science and Technology, Qingdao 266042 (China); Zheng, Zhanlong; Gong, Rui [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); Joint Laboratory for Extreme Conditions Matter Properties, Southwest University of Science and Technology and Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621010 (China); Bi, Yutie [Joint Laboratory for Extreme Conditions Matter Properties, Southwest University of Science and Technology and Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621010 (China); Zhang, Lin, E-mail: zhlmy@sina.com [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); Lin, Runxiong, E-mail: qdlrx@qust.edu.cn [Engineering Research Center of High Performance Polymer and Molding Technology, Ministry of Education, Qingdao University of Science and Technology, Qingdao 266042 (China)

2016-11-01

To investigate the influence of both the first luminescent additive and the wavelength-shifter on the performance of plastic scintillator, a series of polystyrene-based scintillator had been prepared by thermal polymerization. Three first luminescent additives (PPO, p-TP and b-PBD) and four wavelength-shifters (POPOP, Bis-MSB, Me-MSB and DPA) were added to the scintillators respectively. The comparison results showed that PPO and POPOP were the most adequate fluorescent dyes for the polystyrene-based plastic scintillator. Moreover, with the increase of the concentration of PPO and POPOP, the fluorescence intensity and light yield were increased firstly and then decreased. The plastic scintillator containing 2% PPO and 0.02% POPOP had the highest fluorescence intensity and light yield.

Measurement of gamma quantum interaction point in plastic scintillator with WLS strips

Energy Technology Data Exchange (ETDEWEB)

Smyrski, J., E-mail: smyrski@if.uj.edu.pl [Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, S. Łojasiewicza 11, 30-348 Cracow (Poland); Alfs, D.; Bednarski, T.; Białas, P.; Czerwiński, E.; Dulski, K.; Gajos, A.; Głowacz, B.; Gupta-Sharma, N. [Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, S. Łojasiewicza 11, 30-348 Cracow (Poland); Gorgol, M.; Jasińska, B. [Department of Nuclear Methods, Institute of Physics, Maria Curie-Sklodowska University, 20-031 Lublin (Poland); Kajetanowicz, M.; Kamińska, D.; Korcyl, G. [Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, S. Łojasiewicza 11, 30-348 Cracow (Poland); Kowalski, P. [Świerk Computing Centre, National Centre for Nuclear Research, 05-400 Otwock-Świerk (Poland); Krzemień, W. [High Energy Department, National Centre for Nuclear Research, 05-400 Otwock-Świerk (Poland); Krawczyk, N.; Kubicz, E.; Mohammed, M.; Niedźwiecki, Sz. [Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, S. Łojasiewicza 11, 30-348 Cracow (Poland); and others

2017-04-11

The feasibility of measuring the aśxial coordinate of a gamma quantum interaction point in a plastic scintillator bar via the detection of scintillation photons escaping from the scintillator with an array of wavelength-shifting (WLS) strips is demonstrated. Using a test set-up comprising a BC-420 scintillator bar and an array of sixteen BC-482A WLS strips we achieved a spatial resolution of 5 mm (σ) for annihilation photons from a {sup 22}Na isotope. The studied method can be used to improve the spatial resolution of a plastic-scintillator-based PET scanner which is being developed by the J-PET collaboration.

Practical use of a plastic scintillator for quality assurance of electron beam therapy.

Science.gov (United States)

Yogo, Katsunori; Tatsuno, Yuya; Tsuneda, Masato; Aono, Yuki; Mochizuki, Daiki; Fujisawa, Yoshiki; Matsushita, Akihiro; Ishigami, Minoru; Ishiyama, Hiromichi; Hayakawa, Kazushige

2017-06-07

Quality assurance (QA) of clinical electron beams is essential for performing accurate and safe radiation therapy. However, with advances in radiation therapy, QA has become increasingly labor-intensive and time-consuming. In this paper, we propose a tissue-equivalent plastic scintillator for quick and easy QA of clinical electron beams. The proposed tool comprises a plastic scintillator plate and a charge-coupled device camera that enable the scintillation light by electron beams to be recorded with high sensitivity and high spatial resolution. Further, the Cerenkov image is directly subtracted from the scintillation image to discriminate Cerenkov emissions and accurately measure the dose profiles of electron beams with high spatial resolution. Compared with conventional methods, discrepancies in the depth profile improved from 7% to 2% in the buildup region via subtractive corrections. Further, the output brightness showed good linearity with dose, good reproducibility (deviations below 1%), and dose rate independence (within 0.5%). The depth of 50% dose measured with the tool, an index of electron beam quality, was within  ±0.5 mm of that obtained with an ionization chamber. Lateral brightness profiles agreed with the lateral dose profiles to within 4% and no significant improvement was obtained using Cerenkov corrections. Field size agreed to within 0.5 mm with those obtained with ionization chamber. For clinical QA of electron boost treatment, a disk scintillator that mimics the shape of a patient's breast is applied. The brightness distribution and dose, calculated using a treatment planning system, was generally acceptable for clinical use, except in limited zones. Overall, the proposed plastic scintillator plate tool efficiently performs QA for electron beam therapy and enables simultaneous verification of output constancy, beam quality, depth, and lateral dose profiles during monthly QAs at lower doses of irradiation (small monitor units, MUs).

Radiation damage studies on the optical and mechanical properties of plastic scintillators

International Nuclear Information System (INIS)

Mizue Hamada, Margarida; Roberto Rela, Paulo; Eduardo da Costa, Fabio; Henrique de Mesquita, Carlos

1999-01-01

This paper describes the radiation damage studies on a large volume plastic scintillator based in polystyrene doped with PPO and POPOP. The consequences on their mechanical and scintillation properties were evaluated before and after irradiation with different dose rates of 60 Co gamma radiation, in several doses. The optical results show a significant difference in the radiation susceptibility, when the plastic scintillator is irradiated at low rate (0.1 kGy/h) with that irradiated at high dose rate (85 kGy/h). The losses in the optical and mechanical properties increase as the irradiation dose is increased. The damage evaluated by the transmittance, emission intensity, pulse height and tensile strength was normalized as a damage fraction and fitted by a bi-exponential function. It was observed that the damage for irradiation is not permanent and it obeys a bi-exponential function

Study of primary energy transfer process in ultrafast plastic scintillators

International Nuclear Information System (INIS)

Bengtson, B.; Moszynski, M.

1978-01-01

The study of the light-pulse shape, the initial delay of light pulses and the light yield of plastics prepared by a modification of the NE111 scintillator were performed. The NE111 scintillator doped with several quench agents, the plastics prepared as a solution of butyl PBD in PVT of different concentration and PVT alone were studied. The study confirmed that the light pulse shape from fast binary plastics is well described analytically by the convolution of the clipped Gaussian and exponential functions. The investigation of the PVT-butyl PBD plastics shows that even more than three times larger concentration of butyl PBD compared to that of PBD in the NE111 solution does not improve the rise of the light pulse. Thus the rise time seems to be not controlled by the intermolecular energy transfer process. Finally, the observed rise time of the light pulse from the PVT sample was also approximated well by the Gaussian function. Altogether it brought a strong support for the earlier hypothesis that the initial slow rise of light pulses from plastic scintillators may come from the deexcitation of several higher levels of the solvent molecules excited by nuclear particles. (Auth.)

Development of plastic scintillators for use in the field of radioprotection and environmental monitoring

International Nuclear Information System (INIS)

Mesquita, C.H. de; Hamada, M.M.; Chandra, U.

1986-01-01

A plastic scintillator detector based on available know how, for applications in radiological protection - whole body counting, continuous monitoring of air and measurement of low level alpha and beta radioactivity environmental samples is described. Results of method of preparation of the plastic scintillator using styrene monomer and PPO (scintillator), POPOP (wave lenght shifter) are described. For measurement of gamma radiation point sources of 60 Co, 137 Cs and 125 I were used and detected with plastic scintillator detectors prepared with various concentrations (% by weight) of PPO. The data of relative pulse heights are presented. For measurement of alpha and beta radioactivity in environmental samples, thin discs of plastic detector were machined and polished. (Author) [pt

Radiation dosimeter built with plastic scintillator

International Nuclear Information System (INIS)

Barrea, R.A.

1990-01-01

Ionization chambers, with air equivalent plastic walls, have been used as the main x-ray dosimetry system, since its response permits to give the doses in Roentgens. From the commercial availability of plastic scintillators with air equivalent atomic number we have studied its use in x-ray dosimetry. This paper devised a system with which it is possible to reduce side effects that introduce errors and obtain a response independent of energy, from 20 to 180 KeV and it is also expected to behave that way for higher energies. The system has a high efficiency and precision for a wide dose range and it is then a new alternative to measure x-ray doses. Results obtained with a prototype, built ad-hog, make it possible its use with dosimetric purposes with several advantages over conventional. (author)

Calibration method of the pulsed X-ray relative sensitivity for ST401 plastic scintillators

International Nuclear Information System (INIS)

Xie Hongwei; Song Guzhou; Wang Kuilu

2011-01-01

The relative sensitivity calibration method of the pulsed X-ray in ST401 plastic scintillator is presented. Experimental relative sensitivity calibrations of the plastic scintillators of different thicknesses from 1 mm to 50 mm are accomplished on the 'Chenguang' pulsed X-ray source and a Co radioactive source, The uncertainty of the calibration data is evaluated, which can be treated as the experimental evidence for the relative sensitivity conversion of ST401 plastic scintillator. (authors)

Development of plastic scintillator based food radioactivity contamination monitoring system

International Nuclear Information System (INIS)

Parihar, A.; Sahani, R.M.; Mahala, V.K.; Vaijapurkar, S.G.

2016-01-01

Radioactivity is naturally present in soil, water and food stuffs. Food can be contaminated after discharge of radioactivity into the environment from industries that concentrate natural radionuclide and from civil or military nuclear operations. The contamination can be in three ways; by direct deposition, through the food chain and induced radioactivity due to exposure of high neutron flux. The health effects on human depend on the type of radionuclide and the length of time people are exposed to it. The studies of fission product behaviour in the food chain have revealed radionuclide Strontium-90, Caesium 137 and Iodine-131 are of major concern. Plastic scintillator is already developed indigenously at Defence Laboratory, Jodhpur. Efforts has been made to develop a portable field instrument using plastic scintillator for assessment of beta ( 90 Sr) and gamma ( 137 Cs and 131 I) radioactivity in food

Monte Carlo simulations and measurements for efficiency determination of lead shielded plastic scintillator detectors

Science.gov (United States)

Yasin, Zafar; Negoita, Florin; Tabbassum, Sana; Borcea, Ruxandra; Kisyov, Stanimir

2017-12-01

The plastic scintillators are used in different areas of science and technology. One of the use of these scintillator detectors is as beam loss monitors (BLM) for new generation of high intensity heavy ion in superconducting linear accelerators. Operated in pulse counting mode with rather high thresholds and shielded by few centimeters of lead in order to cope with radiofrequency noise and X-ray background emitted by accelerator cavities, they preserve high efficiency for high energy gamma ray and neutrons produced in the nuclear reactions of lost beam particles with accelerator components. Efficiency calculation and calibration of detectors is very important before their practical usage. In the present work, the efficiency of plastic scintillator detectors is simulated using FLUKA for different gamma and neutron sources like, 60Co, 137Cs and 238Pu-Be. The sources are placed at different positions around the detector. Calculated values are compared with the measured values and a reasonable agreement is observed.

Fluorescent compounds for plastic scintillation applications

International Nuclear Information System (INIS)

Pla-Dalmau, A.; Bross, A.D.

1994-04-01

Several 2-(2'-hydroxyphenyl)benzothiazole, -benzoxazole, and -benzimidazole derivatives have been prepared. Transmittance, fluorescence, light yield, and decay time characteristics of these compounds have been studied in a polystyrene matrix and evaluated for use in plastic scintillation detectors. Radiation damage studies utilizing a 60 C source have also been performed

SU-F-T-239: Evaluation of Plastic Scintillator Light Output for Various Lead Doping Concentrations: Towards LET Detection

International Nuclear Information System (INIS)

Nusrat, H; Pang, G; Sarfehnia, A

2016-01-01

Purpose: This work seeks to develop a beam quality meter using multiple differently doped plastic scintillators that are thus intrinsically beam-quality dependent. Plastic scintillators spontaneously emit visible light upon irradiation; the amount of light produced is dependent on stopping power (closely related to LET) according to Birks’ law. Doping plastic scintillators can be used to tune their sensitivity to specific LET ranges. Methods: GEANT4.10.1 Monte Carlo (MC) was used to evaluate the response of various scintillator dopant combinations. MC radiation transport and scintillator light response were validated against previously published literature. Current work involves evaluating detector response experimentally; to that end, a detector prototype with interchangeable scintillator housing was constructed. Measurement set-up guides light emitted by the scintillator to a photomultiplier tube via a glass taper junction coupled to an optical fiber. The resulting signal is measured by an electrometer, and normalized to dose readout from a diode. Measurements have been done using clinical electron and orthovoltage beams. MC response (simulated scintillator light normalized to dose scored inside the scintillating volume) was evaluated for four different LET radiations for an undoped and 1%Pb doped scintillator (σ=0.85%). Simulated incident electrons included: 0.05, 0.1, 0.2, 6, 12, and 18 MeV; these energies correspond to a range of stopping power (related to LET) values ranging from 1.824 to 11.09 MeVcm"2g"−"1 (SCOL from NIST-ESTAR). Results: Initial MC results show a distinct divergence in scintillator response as LET increases. The response for undoped plastic scintillator indicated a 35.0% increase in signal when going from 18 MeV (low LET) to 0.05 MeV (high LET) while 1%-Pb doped scintillator indicated a 100.9% increase. Conclusion: After validating MC against measurement, simulations will be used to test various concentrations (2%, 4%, 6%) of different

SU-F-T-239: Evaluation of Plastic Scintillator Light Output for Various Lead Doping Concentrations: Towards LET Detection

Energy Technology Data Exchange (ETDEWEB)

Nusrat, H [Ryerson University, Toronto, ON (Canada); Pang, G; Sarfehnia, A [Sunnybrook Health Sciences Centre, Toronto, ON (Canada)

2016-06-15

Purpose: This work seeks to develop a beam quality meter using multiple differently doped plastic scintillators that are thus intrinsically beam-quality dependent. Plastic scintillators spontaneously emit visible light upon irradiation; the amount of light produced is dependent on stopping power (closely related to LET) according to Birks’ law. Doping plastic scintillators can be used to tune their sensitivity to specific LET ranges. Methods: GEANT4.10.1 Monte Carlo (MC) was used to evaluate the response of various scintillator dopant combinations. MC radiation transport and scintillator light response were validated against previously published literature. Current work involves evaluating detector response experimentally; to that end, a detector prototype with interchangeable scintillator housing was constructed. Measurement set-up guides light emitted by the scintillator to a photomultiplier tube via a glass taper junction coupled to an optical fiber. The resulting signal is measured by an electrometer, and normalized to dose readout from a diode. Measurements have been done using clinical electron and orthovoltage beams. MC response (simulated scintillator light normalized to dose scored inside the scintillating volume) was evaluated for four different LET radiations for an undoped and 1%Pb doped scintillator (σ=0.85%). Simulated incident electrons included: 0.05, 0.1, 0.2, 6, 12, and 18 MeV; these energies correspond to a range of stopping power (related to LET) values ranging from 1.824 to 11.09 MeVcm{sup 2}g{sup −1} (SCOL from NIST-ESTAR). Results: Initial MC results show a distinct divergence in scintillator response as LET increases. The response for undoped plastic scintillator indicated a 35.0% increase in signal when going from 18 MeV (low LET) to 0.05 MeV (high LET) while 1%-Pb doped scintillator indicated a 100.9% increase. Conclusion: After validating MC against measurement, simulations will be used to test various concentrations (2%, 4%, 6%) of

A high granularity plastic scintillator tile hadronic calorimeter with APD readout for a linear collider detector

Czech Academy of Sciences Publication Activity Database

Andreev, V.; Cvach, Jaroslav; Danilov, M.; Devitsin, E.; Dodonov, V.; Eigen, G.; Garutti, E.; Gilitzky, Yu.; Groll, M.; Heuer, R.D.; Janata, Milan; Kacl, Ivan; Korbel, V.; Kozlov, V. Yu; Meyer, H.; Morgunov, V.; Němeček, Stanislav; Pöschl, R.; Polák, Ivo; Raspereza, A.; Reiche, S.; Rusinov, V.; Sefkow, F.; Smirnov, P.; Terkulov, A.; Valkár, Š.; Weichert, Jan; Zálešák, Jaroslav

2006-01-01

Roč. 564, - (2006), s. 144-154 ISSN 0168-9002 R&D Projects: GA MŠk(CZ) LC527; GA MŠk(CZ) 1P05LA259; GA ČR(CZ) GA202/05/0653 Institutional research plan: CEZ:AV0Z10100502 Keywords : hadronic calorimeter * plastic scintillator tile * APD readout * linear collider detector Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 1.185, year: 2006

Preparation of plastic scintillator detectors and physicochemical parameter characterization

International Nuclear Information System (INIS)

Hamada, M.M.; Mesquita, C.H. de.

1988-10-01

The development of plastic scintillators for use in the nuclear radiation detection is described. The detectors were fabricated by the polymerization of styrene with organic fluors. The organic fluors used were PPO (1,4 diphenyl-oxazol) and POPOP 1,4-di-2-(5-phenyl-oxazolil) - benzene in proportions of 0,5 and 0,05% respectively. Physicochemical parameters related to the quality of this detector are investigated at this laboratory. The evaluation of its fluorescence characteristics, density, melting softening, refractive index, molecular weight, gamma and alpha spectrometry characteristics and finally the comparative pulse height analysis indicate that the plastic scintillator produced at this laboratory is comparable with others already described. (author)

Studies of novel plastic scintillators

International Nuclear Information System (INIS)

McInally, I.D.

1979-08-01

The general aim of this study was to synthesize fluorescent compounds which are capable of polymerisation, to prepare polymers and co-polymers from these compounds and to study the photophysical properties of these materials. In this way it is hoped to produce plastic scintillators exhibiting improved energy transfer efficiency. Materials studied included POS(2-phenyl-5-(p vinyl) phenyloxazole) vinyl naphthalene, methyl anthracene terminated poly vinyl toluene) and derivatives of BuPBD. (author)

X-ray detection capabilities of plastic scintillators incorporated with hafnium oxide nanoparticles surface-modified with phenyl propionic acid

Science.gov (United States)

Hiyama, Fumiyuki; Noguchi, Takio; Koshimizu, Masanori; Kishimoto, Shunji; Haruki, Rie; Nishikido, Fumihiko; Yanagida, Takayuki; Fujimoto, Yutaka; Aida, Tsutomu; Takami, Seiichi; Adschiri, Tadafumi; Asai, Keisuke

2018-01-01

We synthesized plastic scintillators incorporated with HfO2 nanoparticles as detectors for X-ray synchrotron radiation. Nanoparticles with sizes of less than 10 nm were synthesized with the subcritical hydrothermal method. The detection efficiency of high-energy X-ray photons improved by up to 3.3 times because of the addition of the nanoparticles. Nanosecond time resolution was successfully achieved for all the scintillators. These results indicate that this method is applicable for the preparation of plastic scintillators to detect X-ray synchrotron radiation.

Time-resolved plastic scintillator dosimetry in a dynamic thorax phantom

DEFF Research Database (Denmark)

Sibolt, Patrik; Andersen, Claus E.; Ottosson, Wiviann

2017-01-01

in a lung. The phantom motion was controlled by a script in-house developed using LabVIEW (National Instruments) and synchronized with the in-house developed ME40 scintillator dosimetry system (DTU Nutech). The dose in the center of the tumor was measured, using a BCF-60 plastic scintillator detector (Saint...

Modelling plastic scintillator response to gamma rays using light transport incorporated FLUKA code

Energy Technology Data Exchange (ETDEWEB)

Ranjbar Kohan, M. [Physics Department, Tafresh University, Tafresh (Iran, Islamic Republic of); Etaati, G.R. [Department of Nuclear Engineering and Physics, Amir Kabir University of Technology, Tehran (Iran, Islamic Republic of); Ghal-Eh, N., E-mail: ghal-eh@du.ac.ir [School of Physics, Damghan University, Damghan (Iran, Islamic Republic of); Safari, M.J. [Department of Energy Engineering, Sharif University of Technology, Tehran (Iran, Islamic Republic of); Afarideh, H. [Department of Nuclear Engineering and Physics, Amir Kabir University of Technology, Tehran (Iran, Islamic Republic of); Asadi, E. [Department of Physics, Payam-e-Noor University, Tehran (Iran, Islamic Republic of)

2012-05-15

The response function of NE102 plastic scintillator to gamma rays has been simulated using a joint FLUKA+PHOTRACK Monte Carlo code. The multi-purpose particle transport code, FLUKA, has been responsible for gamma transport whilst the light transport code, PHOTRACK, has simulated the transport of scintillation photons through scintillator and lightguide. The simulation results of plastic scintillator with/without light guides of different surface coverings have been successfully verified with experiments. - Highlights: Black-Right-Pointing-Pointer A multi-purpose code (FLUKA) and a light transport code (PHOTRACK) have been linked. Black-Right-Pointing-Pointer The hybrid code has been used to generate the response function of an NE102 scintillator. Black-Right-Pointing-Pointer The simulated response functions exhibit a good agreement with experimental data.

Experimental tests of the new plastic scintillator with pulse shape discrimination capabilities EJ-299-33

Energy Technology Data Exchange (ETDEWEB)

Cester, D., E-mail: davide.cester@gmail.com [Dipartimento di Fisica ed Astronomia dell' Università di Padova, Via Marzolo 8, I-35131 Padova (Italy); Nebbia, G. [INFN Sezione di Padova, Via Marzolo 8, I-35131 Padova (Italy); Stevanato, L. [Dipartimento di Fisica ed Astronomia dell' Università di Padova, Via Marzolo 8, I-35131 Padova (Italy); Pino, F. [Laboratorio de Fisica Nuclear, Universidad Simon Bolivar, Apartado 89000, 1080 A Caracas (Venezuela, Bolivarian Republic of); Viesti, G. [Dipartimento di Fisica ed Astronomia dell' Università di Padova, Via Marzolo 8, I-35131 Padova (Italy)

2014-01-21

We have studied the prototype of a new plastic scintillator material (EJ-299-33) engineered for gamma-neutron discrimination. Energy and time resolutions as well as pulse shape discrimination capability have been compared with those of standard plastic and liquid scintillators. EJ-299-33 characteristics are somewhat poorer compared to standard scintillators. However, results obtained with the new plastic material suggest its possible use in basic research (time-of-flight measurements) as well as in Homeland Security applications (neutron/gamma monitoring device)

High-Z Nanoparticle/Polymer Nanocomposites for Gamma-Ray Scintillation Detectors

Science.gov (United States)

Liu, Chao

An affordable and reliable solution for spectroscopic gamma-ray detection has long been sought after due to the needs from research, defense, and medical applications. Scintillators resolve gamma energy by proportionally converting a single high-energy photon into a number of photomultiplier-tube-detectable low-energy photons, which is considered a more affordable solution for general purposes compared to the delicate semiconductor detectors. An ideal scintillator should simultaneously exhibit the following characteristics: 1) high atomic number (Z) for high gamma stopping power and photoelectron production; 2) high light yield since the energy resolution is inversely proportional to the square root of light yield; 3) short emission decay lifetime; and 4) low cost and scalable production. However, commercial scintillators made from either inorganic single crystals or plastics fail to satisfy all requirements due to their intrinsic material properties and fabrication limitations. The concept of adding high-Z constituents into plastic scintillators to harness high Z, low cost, and fast emission in the resulting nanocomposite scintillators is not new in and of itself. Attempts have been made by adding organometallics, quantum dots, and scintillation nanocrystals into the plastic matrix. High-Z organometallics have long been used to improve the Z of plastic scintillators; however, their strong spin-orbit coupling effect entails careful triplet energy matching using expensive triplet emitters to avoid severe quenching of the light yield. On the other hand, reported quantum dot- and nanocrystal-polymer nanocomposites suffer from moderate Z and high optical loss due to aggregation and self-absorption at loadings higher than 10 wt%, limiting their potential for practical application. This dissertation strives to improve the performance of nanoparticle-based nanocomposite scintillators. One focus is to synthesize transparent nanocomposites with higher loadings of high

Timing performance of plastic scintillators of various sizes in a beam test

International Nuclear Information System (INIS)

Zhao Li; Jiang Linli; Chinese Acacdemy of Sciences, Beijing; Heng Yuekun; Wu Chong; Zhao Xiaojian; Sun Zhijia; Wu Jinjie; Wang Yifang; Zhao Yuda; Nanjing Univ., Nanjing; Wang Fengmei

2006-01-01

The time-of-flight detector of the Beijing Spectrometer III(BES III) is built with long and narrow plastic scintillator bars, with each being 2.3 m long and 6 cm wide. The time resolution of prototypes wrapped with aluminum film has been studied for various thickness of the scintillator using a test beam at the Institute of High Energy Physics in Beijing, China. In this paper, the position-dependent time resolution of the scintillator with a thickness of 4 cm, 5 cm and 6 cm is presented and compared with a Monte Carlo simulation, the results show that the bar with a thickness of 5 cm has the best performance. (authors)

Linear luminescence for thin plastic scintillator under intense soft X-ray irradiation

International Nuclear Information System (INIS)

Ning Jiamin; Jiang Shilun; Xu Rongkun; Guo Cun

2006-01-01

The basic principle of soft X-ray power meter is introduced in the paper and the experimental process and the result of thin plastic scintillator linear luminescence under intense soft X-ray irradiation are described. A range of flux density of energy for thin plastic scintillator linear luminescence under intense soft X-ray irradiation is included. The upper limit of the flux density is 1.47 x 10 5 W/cm 2 . (authors)

Development of metallic molds for the large volume plastic scintillator fabrication

International Nuclear Information System (INIS)

Calvo, Wilson A.P.; Vieira, Jose M.; Rela, Paulo R.; Bruzinga, Wilson A.; Araujo, Eduardo P.; Costa Junior, Nelson P.; Hamada, Margarida M.

1997-01-01

The plastic scintillators are radiation detectors made of organic fluorescent compounds dissolved in a solidified polymer matrix. The manufacturing process of large volume detectors (55 liters) at low cost, by polymerization of the styrene monomer plus PPO and POPOP scintillators, was studied in this paper. Metallic molds of ASTM 1200 aluminum and AISI 304 stainless steel were produced by TIG welding process since the polymerization reaction is very exothermic. The measurements of transmittance, luminescence, X-ray fluorescence and light output were carried out in the plastic scintillators made using different metallic molds. The characterization results of the detectors produced in an open system using ASTM 1200 aluminum mold show that there is not quality change in the scintillator, even with aluminum being considered as unstable for styrene monomer. Therefore, the ASTM 1200 aluminum was found to be the best alternative to produce the detector by an open system polymerization. (author). 11 refs., 8 figs., 1 tab

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.

Scintillating plastic optical fiber radiation detectors in high energy particle physics

International Nuclear Information System (INIS)

Bross, A.D.

1991-01-01

We describe the application of scintillating optical fiber in instrumentation for high energy particle physics. The basic physics of the scintillation process in polymers is discussed first and then we outline the fundamentals of scintillating fiber technology. Fiber performance, optimization, and characterization measurements are given. Detector applications in the areas of particle tracking and particle energy determination are then described. 13 refs., 12 figs

Radiation-damage measurements on PVT-based plastic scintillators

International Nuclear Information System (INIS)

Ilie, S.; Schoenbacher, H.; Tavlet, M.

1993-01-01

Samples of PVT-based plastic scintillators produced by Nuclear Enterprise Technology Ltd. (NET) were irradiated up to 9 kGy, both with a gamma source and within a typical accelerator radiation field (CERN PS ACOL Irradiation Facility). The consequent reduction of scintillating efficiency and light transmission were measured, as well as subsequent recovery, over a period of several months. The main results show that irradiation affects more the light transmission than the light emission. The radiation type does not affect either the amount of transmission reduction or the recovery. Observations were also made by means of polarized light. Non-uniformities and internal stresses were observed in scintillator bulks which were polymerized too quickly. These defects influence the light transmission. (orig.)

Properties of high pressure nitrogen-argon and nitrogen-xenon gas scintillators

International Nuclear Information System (INIS)

Tornow, W.; Huck, H.; Koeber, H.J.; Mertens, G.

1976-01-01

Investigations of scintillation light output and energy resolution have been made at pressures up to 90 atm in gaseous mixtures of nitrogen with both argon and xenon by stopping of 210 Po-alpha particles. In the absence of a wavelength shifter, the N 2 -Ar mixtures gave a maximum pulse height at a ratio of nitrogen to argon partial pressures rsub(N 2 /Ar) approximately =0.2. However, when using the wavelength shifter diphenyl stilbene (DPS), the measured light output was much larger at lower values of rsub(N 2 /Ar), whereas for rsub(N 2 /Ar)>0.2 pulse height and energy resolution of the studied N 2 -Ar mixtures were roughly indentical with and without DPS. The N 2 -Xe gas mixtures exhibited a similar dependence of pulse height and energy resolution to that of the N 2 -Ar mixtures employing DPS, but the pulse height was larger by a factor of about 7. A 40 atm 50% N 2 -50% Xe gas scintillator showed an energy resolution ΔE/E=0.25, while an 80 atm 75% N 2 -25% Xe scintillator gave ΔE/E=0.6. The pulse height from the 80 atm N 2 -Xe scintillator was smaller by a factor of about 240 than the pulse height from a 20 atm pure Xe gas scintillator, but larger by a factor of about 20 than the pulse height from a 75 atm pure N 2 gas scintillator. The N 2 -Xe mixtures showed a remarkable increase of light output as the temperature of the gas was descreased. (Auth.)

A miniature gamma ray dosimeter with CWO scintillator and plastic optical fiber combination

International Nuclear Information System (INIS)

Jae Woo Park, Min Woo Seo

2008-01-01

Full text: Fiber-optic scintillation dosimeters possess several favorable characteristics, such as remote measurability and superior spatial resolution. Such a radiation dosimeter model was developed by attaching a small piece of CWO (CdWO 4 ) scintillator to a low attenuation plastic optical fiber. CWO was chosen since the higher atomic numbers of Cd and W would render the size of the scintillator smaller. The size of the scintillator was 4.7x4.7x10 mm 3 . The scintillator was optically glued to the plastic optical fiber of 3 mm diameter and 10 m length. A current-type PMT was optically coupled to the other end of the fiber to convert the lights generated in the scintillator into current signals. The dosimeter model was tested with two 60 Co standard sources of 0.5 mCi and 1 mCi to measure the PMT current as a function of the source-to-detector distance. It was then tested in a 60 Co irradiation chamber with an activity of about 6600 Ci. MCNPX simulations were performed for the source and detector arrangements to calculate the deposited energy in the CWO scintillator. The profiles of the measured current change are compared with those of the calculated energy deposition change. While there is some deviation between the measured and calculated profiles obtained with the lower-activity standard sources, the measured profile accurately coincides with the calculated one obtained in the higher-activity irradiation chamber. This study suggests that the fiber-optic scintillation dosimeter, operated in current mode, can be used to remotely measure radiation doses in high-intensity gamma fields

Sensitive and transportable gadolinium-core plastic scintillator sphere for neutron detection and counting

Energy Technology Data Exchange (ETDEWEB)

Dumazert, Jonathan; Coulon, Romain; Carrel, Frédérick; Corre, Gwenolé; Normand, Stéphane [CEA, LIST, Laboratoire Capteurs Architectures Electroniques, 91191 Gif-sur-Yvette (France); Méchin, Laurence [CNRS, UCBN, Groupe de Recherche en Informatique, Image, Automatique et Instrumentation de Caen, 14050 Caen (France); Hamel, Matthieu [CEA, LIST, Laboratoire Capteurs Architectures Electroniques, 91191 Gif-sur-Yvette (France)

2016-08-21

Neutron detection forms a critical branch of nuclear-related issues, currently driven by the search for competitive alternative technologies to neutron counters based on the helium-3 isotope. The deployment of plastic scintillators shows a high potential for efficient detectors, safer and more reliable than liquids, more easily scalable and cost-effective than inorganic. In the meantime, natural gadolinium, through its 155 and mostly 157 isotopes, presents an exceptionally high interaction probability with thermal neutrons. This paper introduces a dual system including a metal gadolinium core inserted at the center of a high-scale plastic scintillator sphere. Incident fast neutrons are thermalized by the scintillator shell and then may be captured with a significant probability by gadolinium 155 and 157 nuclei in the core. The deposition of a sufficient fraction of the capture high-energy prompt gamma signature inside the scintillator shell will then allow discrimination from background radiations by energy threshold, and therefore neutron detection. The scaling of the system with the Monte Carlo MCNPX2.7 code was carried out according to a tradeoff between the moderation of incident fast neutrons and the probability of slow neutron capture by a moderate-cost metal gadolinium core. Based on the parameters extracted from simulation, a first laboratory prototype for the assessment of the detection method principle has been synthetized. The robustness and sensitivity of the neutron detection principle are then assessed by counting measurement experiments. Experimental results confirm the potential for a stable, highly sensitive, transportable and cost-efficient neutron detector and orientate future investigation toward promising axes.

Sensitive and transportable gadolinium-core plastic scintillator sphere for neutron detection and counting

International Nuclear Information System (INIS)

Dumazert, Jonathan; Coulon, Romain; Carrel, Frédérick; Corre, Gwenolé; Normand, Stéphane; Méchin, Laurence; Hamel, Matthieu

2016-01-01

Neutron detection forms a critical branch of nuclear-related issues, currently driven by the search for competitive alternative technologies to neutron counters based on the helium-3 isotope. The deployment of plastic scintillators shows a high potential for efficient detectors, safer and more reliable than liquids, more easily scalable and cost-effective than inorganic. In the meantime, natural gadolinium, through its 155 and mostly 157 isotopes, presents an exceptionally high interaction probability with thermal neutrons. This paper introduces a dual system including a metal gadolinium core inserted at the center of a high-scale plastic scintillator sphere. Incident fast neutrons are thermalized by the scintillator shell and then may be captured with a significant probability by gadolinium 155 and 157 nuclei in the core. The deposition of a sufficient fraction of the capture high-energy prompt gamma signature inside the scintillator shell will then allow discrimination from background radiations by energy threshold, and therefore neutron detection. The scaling of the system with the Monte Carlo MCNPX2.7 code was carried out according to a tradeoff between the moderation of incident fast neutrons and the probability of slow neutron capture by a moderate-cost metal gadolinium core. Based on the parameters extracted from simulation, a first laboratory prototype for the assessment of the detection method principle has been synthetized. The robustness and sensitivity of the neutron detection principle are then assessed by counting measurement experiments. Experimental results confirm the potential for a stable, highly sensitive, transportable and cost-efficient neutron detector and orientate future investigation toward promising axes.

Time dispersion in large plastic scintillation neutron detectors

International Nuclear Information System (INIS)

De, A.; Dasgupta, S.S.; Sen, D.

1993-01-01

Time dispersion (TD) has been computed for large neutron detectors using plastic scintillators. It has been shown that TD seen by the PM tube does not necessarily increase with incident neutron energy, a result not fully in agreement with the usual finding

Study on calibration of neutron efficiency and relative photo-yield of plastic scintillator

International Nuclear Information System (INIS)

Peng Taiping; Zhang Chuanfei; Li Rurong; Zhang Jianhua; Luo Xiaobing; Xia Yijun; Yang Zhihua

2002-01-01

A method used for the calibration of neutron efficiency and the relative photo yield of plastic scintillator is studied. T(p, n) and D(d, n) reactions are used as neutron resources. The neutron efficiencies and the relative photo yields of plastic scintillators 1421 (40 mm in diameter and 5 mm in thickness) and determined in the neutron energy range of 0.655-5 MeV

Methacrylate based cross-linkers for improved thermomechanical properties and retention of radiation detection response in plastic scintillators

Science.gov (United States)

Mahl, Adam; Lim, Allison; Latta, Joseph; Yemam, Henok A.; Greife, Uwe; Sellinger, Alan

2018-03-01

Pulse shape discrimination (PSD) is an important method that can efficiently sort and separate neutron and gamma radiation signals. PSD is currently achieved in plastic scintillators by over-doping poly(vinyl toluene) (PVT) matrices with fluorescent molecules. Meaningful separation of the signals requires addition of >20 wt% 2,5-diphenyloxazole (PPO) fluor in PVT. At these concentrations PPO acts as a plasticizer, negatively affecting the physical properties of the final plastic such as hardness, machinability, and thermomechanical stability. This work addresses these issues by implementing a cost-effective solution using cross-linking chemistry via commercially available bisphenol A dimethacrylate (BPA-DM), and a synthesized fluorinated analogue. Both improve the physical properties of over-doped PPO based plastic scintillators without degrading the measured light yield or PSD and Figure of Merit (FoM). In addition, the fluorinated analogue appears to enhance the hydrophobicity of the surface of the plastic scintillators, which may improve the scintillators' resistance to water diffusion and subsequent radiation response degradation. The new formulations improve the feasibility of widely deploying long lifetime PSD capable plastic scintillators in large area coverage assemblies.

Design and test of a high resolution plastic scintillating fiber detector with intensified CCD readout

International Nuclear Information System (INIS)

Rebourgeard, P.

1991-01-01

We present the design of a particle detector involving a coherent array of 100 000 plastic scintillating microfibers, with an individual core diameter around 50 micrometers, and an intensified bidimensional CCD array. We investigate both theoretically and experimentally the use of polystyrene based scintillators in optical multimodal fibers. The isotropic excitation of modes and the characteristics of energy transfers between the polystyrene matrix and the added fluorescent dyes are of particular interest. An experimental approach is proposed and applied to the development of a new binary scintillator. In order to study the transmission of the signal from the interaction area to the output face, we specify the loss factors, the resolution and the signal to noise ratio within the fiber array. The low light level at the output face of the detector leads us to use image intensifiers in photon counting mode. This requires a detailed analysis of resolutions, gain, noise and detectivity concepts. We propose to describe these strongly correlated notions by the moment generation formalism. Thus, a previous modelisation of the photoelectronic devices allows us to evaluate the performance of the readout chain. A complete detector has been assembled and tested on a high energy hadron beam; the measurements are in good agreement with the modelisation [fr

A mobile antineutrino detector with plastic scintillators

International Nuclear Information System (INIS)

Kuroda, Y.; Oguri, S.; Kato, Y.; Nakata, R.; Inoue, Y.; Ito, C.; Minowa, M.

2012-01-01

We propose a new type segmented antineutrino detector made of plastic scintillators for the nuclear safeguard application. A small prototype was built and tested to measure background events. A satisfactory unmanned field operation of the detector system was demonstrated. Besides, a detailed Monte Carlo simulation code was developed to estimate the antineutrino detection efficiency of the detector.

Synthesis of plastic scintillation microspheres: Alpha/beta discrimination

International Nuclear Information System (INIS)

Santiago, L.M.; Bagán, H.; Tarancón, A.; Garcia, J.F.

2014-01-01

Plastic scintillation microspheres (PSm) have been developed as an alternative for liquid scintillation cocktails due to their ability to avoid the mixed waste, besides other strengths in which the possibility for alpha/beta discrimination is included. The aim of this work was to evaluate the capability of PSm containing two combinations of fluorescence solutes (PPO/POPOP and pT/Bis-MSB) and variable amounts of a second organic solvent (naphthalene) to enhance the alpha/beta discrimination. Two commercial detectors with different Pulse Shape Discrimination performances (Quantulus and Triathler) were used to evaluate the alpha/beta discrimination. An optimal discrimination of alpha/beta particles was reached, with very low misclassification values (2% for beta particles and 0.5% for alpha particles), when PSm containing PPO/POPOP and between 0.6 and 2.0 g of naphthalene were evaluated using Triathler and the appropriate programme for data processing. - Highlights: • Plastic scintillation microspheres for α/β discrimination have been synthesised. • The energy transfer process in PSm with different compositions has been investigated. • The α/β discrimination capabilities of two commercial detectors have been evaluated. • 2% and 0.5% of misclassifications for β and α radionuclides have been achieved respectively

A comparative study of the radiation hardness of plastic scintillators for the upgrade of the Tile Calorimeter of the ATLAS detector

Science.gov (United States)

Liao, S.; Erasmus, R.; Jivan, H.; Pelwan, C.; Peters, G.; Sideras-Haddad, E.

2015-10-01

The influence of radiation on the light transmittance of plastic scintillators was studied experimentally. The high optical transmittance property of plastic scintillators makes them essential in the effective functioning of the Tile calorimeter of the ATLAS detector at CERN. This significant role played by the scintillators makes this research imperative in the movement towards the upgrade of the tile calorimeter. The radiation damage of polyvinyl toluene (PVT) based plastic scintillators was studied, namely, EJ-200, EJ-208 and EJ-260, all manufactured and provided to us by ELJEN technology. In addition, in order to compare to scintillator brands actually in use at the ATLAS detector currently, two polystyrene (PS) based scintillators and an additional PVT based scintillator were also scrutinized in this study, namely, Dubna, Protvino and Bicron, respectively. All the samples were irradiated using a 6 MeV proton beam at different doses at iThemba LABS Gauteng. The radiation process was planned and mimicked by doing simulations using a SRIM program. In addition, transmission spectra for the irradiated and unirradiated samples of each grade were obtained, observed and analyzed.

Plastic fiber scintillator response to fast neutrons

Energy Technology Data Exchange (ETDEWEB)

Danly, C. R.; Sjue, S.; Wilde, C. H.; Merrill, F. E.; Haight, R. C. [Los Alamos National Laboratory, Los Alamos, New Mexico 87544 (United States)

2014-11-15

The Neutron Imaging System at NIF uses an array of plastic scintillator fibers in conjunction with a time-gated imaging system to form an image of the neutron emission from the imploded capsule. By gating on neutrons that have scattered from the 14.1 MeV DT energy to lower energy ranges, an image of the dense, cold fuel around the hotspot is also obtained. An unmoderated spallation neutron beamline at the Weapons Neutron Research facility at Los Alamos was used in conjunction with a time-gated imaging system to measure the yield of a scintillating fiber array over several energy bands ranging from 1 to 15 MeV. The results and comparison to simulation are presented.

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)

Optimization of Plastic Scintillator Thicknesses for Online Beta Detection in Mixed Fields

Energy Technology Data Exchange (ETDEWEB)

Pourtangestani, K.; Machrafi, R. [University of Ontario Institute of Technology, Oshawa, ON (Canada)

2013-07-15

For efficient beta detection in a mixed beta-gamma field, Monte Carlo simulation models have been developed to optimize the thickness of a plastic scintillator used in whole body monitor. The simulation has been performed using MCNP/X code and different thicknesses of plastic scintillators ranging from 150 to 600 {mu}m have been used. The relationship between the thickness of the scintillator and the efficiency of the detector has been analysed. For 150 {mu}m thickness, an experimental investigation has been conducted with different beta sources at different positions on the scintillator and the counting efficiency of the unit has been measured. Evaluated data along with experimental ones have been discussed. A thickness of 300 {mu}m to 500 {mu}m has been found to be an optimum thickness for better beta detection efficiency in the presence of low energy gamma ray. (author)

Temperature variations as a source of uncertainty in medical fiber-coupled organic plastic scintillator dosimetry

DEFF Research Database (Denmark)

Buranurak, Siritorn; Andersen, Claus Erik; Beierholm, Anders Ravnsborg

2013-01-01

Fiber-coupled organic plastic scintillators have potential applications in medical dosimetry related to, for example, brachytherapy and external beam radiotherapy with MV photons. As medical dosimetry generally strives for high accuracy, we designed a study to assess if the light yield from...... commonly used scintillating fibers would change with temperature in the clinical range (15–40 °C). The study showed that the light yield in the peak regions of the scintillators studied decreases linearly with increasing temperature. For the blue BCF-12 and the green BCF-60 from Saint-Gobain, France we...

High pressure studies of fluorenone emission in plastic media

International Nuclear Information System (INIS)

Mitchell, D.J.; Schuster, G.B.; Drickamer, H.G.

1977-01-01

The energy and the quantum efficiency for fluorenone fluorescence in the crystalline state and in polymeric matrices was measured as a function of external pressure over the range 0--140 kbar. The application of high pressure induces changes in the quantum yield, which ranges from 0.001 at low pressure to a maximum of approx.0.1 at high pressure in hydrocarbon plastics. These results are interpreted as arising from the decrease in the energy of the lowest ππ excited singlet state relative to other relevant states as the external pressure is increased

Apllication of plastic scintillators with light intensifiers in photographic dosemeters to increase the sensitivity

International Nuclear Information System (INIS)

Mesquita, C.H. de; Hamada, M.M.

1988-01-01

The purpose of this work is to evaluate the effect of a light converter (plastic scintillator) to use as badge in the conventional photographic dosimeter. In this dosimeter the light is a new component of emulsion sensibilization. So, even radiations that are not able to reach the photographic emulsion can be detected by producing photons in the plastic scintillator. (author) [pt

Scintillation densimeter for liquids and an isotopic conveyor weighers with plastic scintillator

International Nuclear Information System (INIS)

Makhaj, B.; Antonyak, V.; Plyater, Z.

1979-01-01

The method is described of the weighted material's mass measuring according to the results of the conveyor momentary load measurement derived from the attenuation of radiation in the transmission geometry, conveyor belt velocity measurement and digital processing of the signals from the measurement of the bouth values. In the measuring gage there are located: the point type gamma source of cesium-137 with 4 mCi capacity, the scintillation detector with plastic cylindric scintillator of 5 cm in diameter and with the length approximately equal to the width of the conveyor belt and also the tachometer-generator. The conveyor weighers described is intended for use with conveyor having belt; from 60 to 180 cm wide. The results are given of industrial exploitation of the instrument [ru

A new approach to film dosimetry for high-energy photon beams using organic plastic scintillators

International Nuclear Information System (INIS)

Yeo, I.J.; Wang, C.-K.C.; Burch, S.E.

1999-01-01

Successful radiotherapy relies on accurate dose measurement. Traditional dosimeters such as ion chambers, TLDs and diodes have disadvantages such as relatively long measurement time and poor spatial resolution. These drawbacks become more serious problems for dynamic beams (i.e. with the use of dynamic wedges or even the intensity modulation technique). X-ray film, an integrating dosimeter, may not be associated with the above disadvantages and problems. However, there are several major issues regarding use of x-ray film for routine dosimetry, including the over-response of the film to low-energy photons, variations in the dose response curve (nonlinearity), lack of reproducibility due to variation in processing, etc. This paper addresses the first problem. That is, x-ray film over-responds to low-energy photons (energies below 400 keV), and thus generates unacceptably inaccurate dosimetric data compared with ion-chamber data. To overcome the over-response problem of x-ray film in a phantom, a scintillation method has been investigated. In this method, a film is sandwiched by two plastic scintillation screens to enhance the film response to upstream electrons, and therefore minimize the over-response caused by low-energy photons. The sandwiched system was tested with a 4 MV linac beam. The result shows that, depending on the uniformity of the scintillation screens, the depth-dose distribution obtained from the sandwich system can be made to agree well with that obtained from ion chambers. However, the required high degree of uniformity remains a challenge for the scintillation screen manufacturers. (author)

Production and thickness determination of thin plastic scintillator foils

International Nuclear Information System (INIS)

Xiao, B.; Lee, S.; Hagel, K.; Haddad, F.; Li, J.; Lou, Y.; Mdeiwayeh, N.; Tezkratt, R.; Wada, R.; Utley, D.; Natowitz, J.B.

1995-01-01

A method of making large thin plastic scintillator foils with good uniformity is presented. The use of Fourier Transform Infrared Spectroscopy (FTIR) to test the foil uniformity and to establish an empirical thickness calibration curve is described. ((orig.))

Development of water radiocontamination monitor using a plastic scintillator detector

International Nuclear Information System (INIS)

Mesquita, C.H. de; Madi Filho, T.; Hamada, M.M.

1990-01-01

An alpha, beta and gamma radiation water monitor was developed using a plastic scintillator detector with a sensitivity level of 15 bplastic scintillator detector with a sensitivity level of 15 Bq.L -1 and a counting efficiency of 25% for 131 I. It was proposed to be used in the radiation monitoring program of the research reactor swimming-pool of Sao Paulo. A simplified design and some properties of this monitor are presented. (author) [pt

Effects of surface coatings on the light collection in plastic scintillators used for radioxenon detection

International Nuclear Information System (INIS)

Bläckberg, L; Klintenberg, M; Sjöstrand, H; Ringbom, A

2012-01-01

Atomic layer deposition coatings are under investigation to reduce the diffusion of radioxenon into plastic scintillators. This paper investigates the impact of such surface coating on the light collection efficiency in a cylindrical geometry. A high and uniform light collection efficiency is important to preserve detector resolution. Monte Carlo simulations and measurements have been carried out to study the influence of coating thickness, refractive index and surface quality. It was found that it is important to achieve a smooth coating and good optical match between the refractive indices of the coating and the plastic scintillator. Taking into account these considerations, the detector under study could be coated without a significant degradation of its resolution.

Brightness and uniformity measurements of plastic scintillator tiles at the CERN H2 test beam

Science.gov (United States)

Chatrchyan, S.; Sirunyan, A. M.; Tumasyan, A.; Litomin, A.; Mossolov, V.; Shumeiko, N.; Van De Klundert, M.; Van Haevermaet, H.; Van Mechelen, P.; Van Spilbeeck, A.; Alves, G. A.; Aldá Júnior, W. L.; Hensel, C.; Carvalho, W.; Chinellato, J.; De Oliveira Martins, C.; Matos Figueiredo, D.; Mora Herrera, C.; Nogima, H.; Prado Da Silva, W. L.; Tonelli Manganote, E. J.; Vilela Pereira, A.; Finger, M.; Finger, M., Jr.; Kveton, A.; Tomsa, J.; Adamov, G.; Tsamalaidze, Z.; Behrens, U.; Borras, K.; Campbell, A.; Costanza, F.; Gunnellini, P.; Lobanov, A.; Melzer-Pellmann, I.-A.; Muhl, C.; Roland, B.; Sahin, M.; Saxena, P.; Hegde, V.; Kothekar, K.; Pandey, S.; Sharma, S.; Beri, S. B.; Bhawandeep, B.; Chawla, R.; Kalsi, A.; Kaur, A.; Kaur, M.; Walia, G.; Bhattacharya, S.; Ghosh, S.; Nandan, S.; Purohit, A.; Sharan, M.; Banerjee, S.; Bhattacharya, S.; Chatterjee, S.; Das, P.; Guchait, M.; Jain, S.; Kumar, S.; Maity, M.; Majumder, G.; Mazumdar, K.; Patil, M.; Sarkar, T.; Juodagalvis, A.; Afanasiev, S.; Bunin, P.; Ershov, Y.; Golutvin, I.; Malakhov, A.; Moisenz, P.; Smirnov, V.; Zarubin, A.; Chadeeva, M.; Chistov, R.; Danilov, M.; Popova, E.; Rusinov, V.; Andreev, Yu.; Dermenev, A.; Karneyeu, A.; Krasnikov, N.; Tlisov, D.; Toropin, A.; Epshteyn, V.; Gavrilov, V.; Lychkovskaya, N.; Popov, V.; Pozdnyakov, I.; Safronov, G.; Toms, M.; Zhokin, A.; Baskakov, A.; Belyaev, A.; Boos, E.; Dubinin, M.; Dudko, L.; Ershov, A.; Gribushin, A.; Kaminskiy, A.; Klyukhin, V.; Kodolova, O.; Lokhtin, I.; Miagkov, I.; Obraztsov, S.; Petrushanko, S.; Savrin, V.; Snigirev, A.; Andreev, V.; Azarkin, M.; Dremin, I.; Kirakosyan, M.; Leonidov, A.; Terkulov, A.; Bitioukov, S.; Elumakhov, D.; Kalinin, A.; Krychkine, V.; Mandrik, P.; Petrov, V.; Ryutin, R.; Sobol, A.; Troshin, S.; Volkov, A.; Sekmen, S.; Medvedeva, T.; Rumerio, P.; Adiguzel, A.; Bakirci, N.; Boran, F.; Cerci, S.; Damarseckin, S.; Demiroglu, Z. S.; Dölek, F.; Dozen, C.; Dumanoglu, I.; Eskut, E.; Girgis, S.; Gokbulut, G.; Guler, Y.; Hos, I.; Kangal, E. E.; Kara, O.; Kayis Topaksu, A.; Işik, C.; Kiminsu, U.; Oglakci, M.; Onengut, G.; Ozdemir, K.; Ozturk, S.; Polatoz, A.; Sunar Cerci, D.; Tali, B.; Tok, U. G.; Topakli, H.; Turkcapar, S.; Zorbakir, I. S.; Zorbilmez, C.; Bilin, B.; Isildak, B.; Karapinar, G.; Murat Guler, A.; Ocalan, K.; Yalvac, M.; Zeyrek, M.; Atakisi, I. O.; Gülmez, E.; Kaya, M.; Kaya, O.; Koseyan, O. K.; Ozcelik, O.; Ozkorucuklu, S.; Tekten, S.; Yetkin, E. A.; Yetkin, T.; Cankocak, K.; Sen, S.; Boyarintsev, A.; Grynyov, B.; Levchuk, L.; Popov, V.; Sorokin, P.; Flacher, H.; Borzou, A.; Call, K.; Dittmann, J.; Hatakeyama, K.; Liu, H.; Pastika, N.; Buccilli, A.; Cooper, S. I.; Henderson, C.; West, C.; Arcaro, D.; Gastler, D.; Hazen, E.; Rohlf, J.; Sulak, L.; Wu, S.; Zou, D.; Hakala, J.; Heintz, U.; Kwok, K. H. M.; Laird, E.; Landsberg, G.; Mao, Z.; Yu, D. R.; Gary, J. W.; Ghiasi Shirazi, S. M.; Lacroix, F.; Long, O. R.; Wei, H.; Bhandari, R.; Heller, R.; Stuart, D.; Yoo, J. H.; Chen, Y.; Duarte, J.; Lawhorn, J. M.; Nguyen, T.; Spiropulu, M.; Winn, D.; Abdullin, S.; Apresyan, A.; Apyan, A.; Banerjee, S.; Chlebana, F.; Freeman, J.; Green, D.; Hare, D.; Hirschauer, J.; Joshi, U.; Lincoln, D.; Los, S.; Pedro, K.; Spalding, W. J.; Strobbe, N.; Tkaczyk, S.; Whitbeck, A.; Linn, S.; Markowitz, P.; Martinez, G.; Bertoldi, M.; Hagopian, S.; Hagopian, V.; Kolberg, T.; Baarmand, M. M.; Noonan, D.; Roy, T.; Yumiceva, F.; Bilki, B.; Clarida, W.; Debbins, P.; Dilsiz, K.; Durgut, S.; Gandrajula, R. P.; Haytmyradov, M.; Khristenko, V.; Merlo, J.-P.; Mermerkaya, H.; Mestvirishvili, A.; Miller, M.; Moeller, A.; Nachtman, J.; Ogul, H.; Onel, Y.; Ozok, F.; Penzo, A.; Schmidt, I.; Snyder, C.; Southwick, D.; Tiras, E.; Yi, K.; Al-bataineh, A.; Bowen, J.; Castle, J.; McBrayer, W.; Murray, M.; Wang, Q.; Kaadze, K.; Maravin, Y.; Mohammadi, A.; Saini, L. K.; Baden, A.; Belloni, A.; Calderon, J. D.; Eno, S. C.; Feng, Y. B.; Ferraioli, C.; Grassi, T.; Hadley, N. J.; Jeng, G.-Y.; Kellogg, R. G.; Kunkle, J.; Mignerey, A.; Ricci-Tam, F.; Shin, Y. H.; Skuja, A.; Yang, Z. S.; Yao, Y.; Brandt, S.; D'Alfonso, M.; Hu, M.; Klute, M.; Niu, X.; Chatterjee, R. M.; Evans, A.; Frahm, E.; Kubota, Y.; Lesko, Z.; Mans, J.; Ruckstuhl, N.; Heering, A.; Karmgard, D. J.; Musienko, Y.; Ruchti, R.; Wayne, M.; Benaglia, A. D.; Mei, K.; Tully, C.; Bodek, A.; de Barbaro, P.; Galanti, M.; Garcia-Bellido, A.; Khukhunaishvili, A.; Lo, K. H.; Vishnevskiy, D.; Zielinski, M.; Agapitos, A.; Amouzegar, M.; Chou, J. P.; Hughes, E.; Saka, H.; Sheffield, D.; Akchurin, N.; Damgov, J.; De Guio, F.; Dudero, P. R.; Faulkner, J.; Gurpinar, E.; Kunori, S.; Lamichhane, K.; Lee, S. W.; Libeiro, T.; Mengke, T.; Muthumuni, S.; Undleeb, S.; Volobouev, I.; Wang, Z.; Goadhouse, S.; Hirosky, R.; Wang, Y.

2018-01-01

We study the light output, light collection efficiency and signal timing of a variety of organic scintillators that are being considered for the upgrade of the hadronic calorimeter of the CMS detector. The experimental data are collected at the H2 test-beam area at CERN, using a 150 GeV muon beam. In particular, we investigate the usage of over-doped and green-emitting plastic scintillators, two solutions that have not been extensively considered. We present a study of the energy distribution in plastic-scintillator tiles, the hit efficiency as a function of the hit position, and a study of the signal timing for blue and green scintillators.

Brightness and uniformity measurements of plastic scintillator tiles at the CERN H2 test beam

Energy Technology Data Exchange (ETDEWEB)

Chatrchyan, S.; et al.

2017-09-25

We study the light output, light collection efficiency and signal timing of a variety of organic scintillators that are being considered for the upgrade of the hadronic calorimeter of the CMS detector. The experimental data are collected at the H2 test-beam area at CERN, using a 150 GeV muon beam. In particular, we investigate the usage of over-doped and green-emitting plastic scintillator, two solutions that have not been extensively considered. We present a study of the energy distribution in plastic-scintillator tiles, the hit efficiency as a function of the hit position, and a study of the signal timing for blue and green scintillators.

Characterization of plastic scintillators for detection of radioactivity: Light yield, Time decay measurements and Neutron/γ Pulse Shape Discrimination

International Nuclear Information System (INIS)

Montbarbon, E.; Pansu, R.B.; Hamel, M.; Coulon, R.

2015-07-01

Since Helium-3 shortage, organic scintillators play a major role in neutron detection. CEA LIST decided to focus on plastic scintillators. By definition, a plastic scintillator is a radio-luminescent polymer; this means that it emits light after interaction with an ionizing radiation. A platform was developed to characterize lab-made prepared scintillators and to compare them with commercial scintillators. Three physicochemical criteria are determined with this unique platform. (authors)

Performance studies towards a TOF-PET sensor using Compton scattering at plastic scintillators

Science.gov (United States)

Kuramoto, M.; Nakamori, T.; Gunji, S.; Kamada, K.; Shoji, Y.; Yoshikawa, A.; Aoki, T.

2018-01-01

We have developed a sensor head for a time-of-flight (TOF) PET scanner using plastic scintillators that have a very fast timing property. Given the very small cross section of photoelectric absorption in plastic scintillators at 511 keV, we use Compton scattering in order to compensate for detection efficiency. The detector will consist of two layers of scatterers and absorbers which are made of plastic and inorganic scintillators such as GAGG:Ce, respectively. Signals are read by monolithic Multi Pixel Photon Counters, and with energy deposits and interaction time stamps are being acquired. The scintillators are built to be capable of resolving interaction position in three dimensions, so that our system has also a function of depth-of-interaction (DOI) PET scanners. TOF resolution of ~ 200 ps (FWHM) is achieved in both cases of using the leading-edge discriminator and time-walk correction and using a configuration sensitive to DOI. Both the position resolution and spectroscopy are demonstrated using the prototype data acquisition system, with Compton scattering events subsequently being obtained. We also demonstrated that the background rejection technique using the Compton cone constraint could be valid with our system.

PMP, a novel solute for liquid and plastic scintillation counting

International Nuclear Information System (INIS)

Gusten, Hans

1983-01-01

The excellent fluorescence properties of PMP ( 11-phenyl-3-mesityl-2-pyrazoline) such as long wavelength emission of over 400 nm, and high fluorescence quantum yield with a short decay time together with a solubility of more than one Mol/L in toluene make this compound a promising solute for scintillation counting. The Stokes' shift of PMP of over 10,000 cm -1 is twice as large as that of the commonly used PPO. Due to this unusually large Stokes' shift PMP can be used as a primary solute without requiring a secondary solute as wavelength shifter. A comparison of the scintillation properties of PMP and PPO in toluene reveals that the counting efficiency for 14 C is better for PMP while the 3 H efficiency is equally good. Due to the large Stokes' shift, PMP is about 50 percent less sensitive to color quenching than PPO. Compared to the solute combinations PPO/secondary solutes, the scintillation counting efficiency of PMP for 14 C in toluene or xylene is the same, while the absolute 3 H efficiency of PPO/secondary solutes in cocktails with emulsifiers is about 10 percent higher. The PMP scintillation efficiency for 14 C as well as 3 H in chemical quenching by urine is more or less the same as for PPO/dimethyl-POPOP. PMP is more sensitive to quenching by halogenated solvents. In the dioxane-based scintillation, this sensitivity to chemical quenching by CHCl 3 vanishes and the counting efficiencies for 14 C and 3 H are as good as for PPO/dimethyl-POPOP or PPO/bis-MSB. Due to the large Stokes' shift, the self-absorption of the scintillation light by PMP is lower than in conventional scintillators. This offers good possibilities in very large-volume applications of liquid as well as plastic scintillators

Neutron/gamma pulse shape discrimination in plastic scintillators: Preparation and characterization of various compositions

International Nuclear Information System (INIS)

Blanc, Pauline; Hamel, Matthieu; Dehé-Pittance, Chrystèle; Rocha, Licinio; Pansu, Robert B.; Normand, Stéphane

2014-01-01

This work deals with the preparation and evaluation of plastic scintillators for neutron/gamma pulse shape discrimination (PSD). We succeeded in developing a plastic scintillator with good neutron/gamma discrimination properties in the range of what is already being commercialized. Several combinations of primary and secondary fluorophores were implemented in chemically modified polymers. These scintillators were fully characterized by fluorescence spectroscopy and under neutron irradiation. The materials proved to be stable for up to 5 years without any degradation of PSD properties. They were then classified in terms of their PSD capabilities and light yield. Our best candidate, 28.6 wt% of primary fluorophore with a small amount of secondary fluorophore, shows promising PSD results and is particularly suited to industrial development, because its preparation does not involve the use of expensive or exotic compounds. Furthermore, even at the highest prepared concentration, high stability over time was observed. As a proof of concept, one sample with dimensions 109 mm ∅×114 mm height (≈1 L) was prepared

Neutron/gamma pulse shape discrimination in plastic scintillators: Preparation and characterization of various compositions

Energy Technology Data Exchange (ETDEWEB)

Blanc, Pauline [CEA, LIST, Laboratoire Capteurs et Architectures Électroniques, F-91191 Gif-sur-Yvette (France); Laboratoire de Photophysique et Photochimie Supramoléculaires et Macromoléculaires (CNRS UMR 8531), École Normale Supérieure de Cachan, 61 Avenue du Président Wilson, F-94235 Cachan cedex (France); Hamel, Matthieu, E-mail: matthieu.hamel@cea.fr [CEA, LIST, Laboratoire Capteurs et Architectures Électroniques, F-91191 Gif-sur-Yvette (France); Dehé-Pittance, Chrystèle; Rocha, Licinio [CEA, LIST, Laboratoire Capteurs et Architectures Électroniques, F-91191 Gif-sur-Yvette (France); Pansu, Robert B. [Laboratoire de Photophysique et Photochimie Supramoléculaires et Macromoléculaires (CNRS UMR 8531), École Normale Supérieure de Cachan, 61 Avenue du Président Wilson, F-94235 Cachan cedex (France); Normand, Stéphane [CEA, LIST, Laboratoire Capteurs et Architectures Électroniques, F-91191 Gif-sur-Yvette (France)

2014-06-01

This work deals with the preparation and evaluation of plastic scintillators for neutron/gamma pulse shape discrimination (PSD). We succeeded in developing a plastic scintillator with good neutron/gamma discrimination properties in the range of what is already being commercialized. Several combinations of primary and secondary fluorophores were implemented in chemically modified polymers. These scintillators were fully characterized by fluorescence spectroscopy and under neutron irradiation. The materials proved to be stable for up to 5 years without any degradation of PSD properties. They were then classified in terms of their PSD capabilities and light yield. Our best candidate, 28.6 wt% of primary fluorophore with a small amount of secondary fluorophore, shows promising PSD results and is particularly suited to industrial development, because its preparation does not involve the use of expensive or exotic compounds. Furthermore, even at the highest prepared concentration, high stability over time was observed. As a proof of concept, one sample with dimensions 109 mm ∅×114 mm height (≈1 L) was prepared.

Preparation of plastic scintillation detectors and characterization of physico-chemical parameters

International Nuclear Information System (INIS)

Hamada, M.M.; Mesquita, C.H. de

1988-01-01

The development of plastic scintillators for using in the nuclear radiation detection is described. The detectors were fabricated by the polymerization of styrene with organic fluors. The organic fluors used were PPO (1,4 difenil-oxazol) and POPOP 1,4-di-2-(5-fenil-oxazolil) benzene in proportions of 0,5 and 0,05% respectively. Physical-chemistry parameters related to the quality of this detector are investigated at this laboratory. The evaluation of its fluorescency characteristics, density, melting softening, refractive index, molecular weight, gama and alfa espectrometry characteristics and finally the comparative pulse height analysis indicate that the plastic scintillator produced at this laboratory is comparable with others already described. (author) [pt

Bismuth- and lithium-loaded plastic scintillators for gamma and neutron detection

International Nuclear Information System (INIS)

Cherepy, Nerine J.; Sanner, Robert D.; Beck, Patrick R.; Swanberg, Erik L.; Tillotson, Thomas M.; Payne, Stephen A.; Hurlbut, Charles R.

2015-01-01

Transparent plastic scintillators based on polyvinyltoluene (PVT) have been fabricated with high loading of bismuth carboxylates for gamma spectroscopy, and with lithium carboxylates for neutron detection. When activated with a combination of standard fluors, 2,5-diphenyloxazole (PPO) and tetraphenylbutadiene (TPB), gamma light yields with 15 wt% bismuth tripivalate of 5000 Ph/MeV are measured. A PVT plastic formulation including 30 wt% lithium pivalate and 30 wt% PPO offers both pulse shape discrimination, and a neutron capture peak at ~400 keVee. In another configuration, a bismuth-loaded PVT plastic is coated with ZnS( 6 Li) paint, permitting simultaneous gamma and neutron detection via pulse shape discrimination with a figure-of-merit of 3.8, while offering gamma spectroscopy with energy resolution of R(662 keV)=15%

Plastic scintillation dosimetry for radiation therapy: minimizing capture of Cerenkov radiation noise

International Nuclear Information System (INIS)

Beddar, A Sam; Suchowerska, Natalka; Law, Susan H

2004-01-01

Over the last decade, there has been an increased interest in scintillation dosimetry using small water-equivalent plastic scintillators, because of their favourable characteristics when compared with other more commonly used detector systems. Although plastic scintillators have been shown to have many desirable dosimetric properties, as yet there is no successful commercial detector system of this type available for routine clinical use in radiation oncology. The main factor preventing this new technology from realizing its full potential in commercial applications is the maximization of signal coupling efficiency and the minimization of noise capture. A principal constituent of noise is Cerenkov radiation. This study reports the calculated capture of Cerenkov radiation by an optical fibre in the special case where the radiation is generated by a relativistic particle on the fibre axis and the fibre axis is parallel to the Cerenkov cone. The fraction of radiation captured is calculated as a function of the fibre core refractive index and the refractive index difference between the core and the cladding of the fibre for relativistic particles. This is then used to deduce the relative intensity captured for a range of fibre core refractive indices and fibre core-cladding refractive index differences. It is shown that the core refractive index has little effect on the amount of radiation captured compared to the refractive index difference. The implications of this result for the design of radiation therapy plastic scintillation dosimeters are considered

Comparative measurements between a Li-6 glass and a He-3 high-pressure gas scintillator

International Nuclear Information System (INIS)

Priesmeyer, H.G.; Fischer, P.; Harz, U.; Soldner, B.

1983-01-01

The He-3 high-pressure gas scintillation neutron detector commercially available as LND 800, has been compated to a Li-6 glass scintillator type NE 912. (n,γ) pulse height discrimination capabilities and neutron detection efficiencies have been determined. The objective of these measurements was to try to improve the Kiel Fast-Chopper TOF detector system by using a gasscintillator, which could cover the neutron beam geometry and by which gamma ray background contributions could be reduced. The time response always meets the requirements of a chopper experiment, but the neutron detection efficiency of the Li-6 glasses now used had to be maintained. (orig./HP) [de

The two plastic scintillator measuring system HBG-2

International Nuclear Information System (INIS)

Tran Manh Toan; Nguyen Trieu Tu

1992-01-01

The beta-gamma measuring system HBG-2 is described. It consist of: 1. Two 40mm Φ x 3mm plastic scintillators, a beta-filter, a shielded cell, and a coincidence circuit; 2. Four counting channels in which one is reversible. A device is capable of measuring low-level activity. Some special measuring methods provided by the equipment are presented, too. (author). 6 refs, 3

Passive neutron coincidence counting with plastic scintillators for the characterization of radioactive waste drums

Energy Technology Data Exchange (ETDEWEB)

Deyglun, C.; Simony, B.; Perot, B.; Carasco, C. [CEA, DEN, Cadarache, Nuclear Measurement Laboratory, F-13108 Saint-Paul-lez-Durance (France); Saurel, N.; Colas, S. [CEA, DAM, Valduc, F-21120 Is-sur-Tille (France); Collot, J. [Laboratoire de Physique Subatomique et de Cosmologie, Universite Grenoble Alpes, CNRS/IN2P3, Grenoble (France)

2015-07-01

The quantification of radioactive material is essential in the fields of safeguards, criticality control of nuclear processes, dismantling of nuclear facilities and components, or radioactive waste characterization. The Nuclear Measurement Laboratory (LMN) of CEA is involved in the development of time-correlated neutron detection techniques using plastic scintillators. Usually, 3He proportional counters are used for passive neutron coincidence counting owing to their high thermal neutron capture efficiency and gamma insensitivity. However, the global {sup 3}He shortage in the past few years has made these detectors extremely expensive. In addition, contrary to {sup 3}He counters for which a few tens of microseconds are needed to thermalize fast neutrons, in view to maximize the {sup 3}He(n,p){sup 3}H capture cross section, plastic scintillators are based on elastic scattering and therefore the light signal is formed within a few nanoseconds, correlated pulses being detected within a few dozen- or hundred nanoseconds. This time span reflects fission particles time of flight, which allows reducing accordingly the duration of the coincidence gate and thus the rate of random coincidences, which may totally blind fission coincidences when using {sup 3}He counters in case of a high (α,n) reaction rate. However, plastic scintillators are very sensitive to gamma rays, requiring the use of a thick metallic shield to reduce the corresponding background. Cross talk between detectors is also a major issue, which consists on the detection of one particle by several detectors due to elastic or inelastic scattering, leading to true but undesired coincidences. Data analysis algorithms are tested to minimize cross-talk in simultaneously activated detectors. The distinction between useful fission coincidences and the correlated background due to cross-talk, (α,n) and induced (n,2n) or (n,n'γ) reactions, is achieved by measuring 3-fold coincidences. The performances of a

Surface coatings as xenon diffusion barriers on plastic scintillators : Improving Nuclear-Test-Ban Treaty verification

OpenAIRE

Bläckberg, Lisa

2011-01-01

This thesis investigates the ability of transparent surface coatings to reduce xenon diffusion into plastic scintillators. The motivation for the work is improved radioxenon monitoring equipment, used with in the framework of the verification regime of the Comprehensive Nuclear-Test-Ban Treaty. A large part of the equipment used in this context incorporates plastic scintillators which are in direct contact with the radioactive gas to be detected. One problem with such setup is that radioxenon...

A feasibility study of ortho-positronium decays measurement with the J-PET scanner based on plastic scintillators

Science.gov (United States)

Kamińska, D.; Gajos, A.; Czerwiński, E.; Alfs, D.; Bednarski, T.; Białas, P.; Curceanu, C.; Dulski, K.; Głowacz, B.; Gupta-Sharma, N.; Gorgol, M.; Hiesmayr, B. C.; Jasińska, B.; Korcyl, G.; Kowalski, P.; Krzemień, W.; Krawczyk, N.; Kubicz, E.; Mohammed, M.; Niedźwiecki, Sz.; Pawlik-Niedźwiecka, M.; Raczyński, L.; Rudy, Z.; Silarski, M.; Wieczorek, A.; Wiślicki, W.; Zgardzińska, B.; Zieliński, M.; Moskal, P.

2016-08-01

We present a study of the application of the Jagiellonian positron emission tomograph (J-PET) for the registration of gamma quanta from decays of ortho-positronium (o-Ps). The J-PET is the first positron emission tomography scanner based on organic scintillators in contrast to all current PET scanners based on inorganic crystals. Monte Carlo simulations show that the J-PET as an axially symmetric and high acceptance scanner can be used as a multi-purpose detector well suited to pursue research including e.g. tests of discrete symmetries in decays of ortho-positronium in addition to the medical imaging. The gamma quanta originating from o-Ps decay interact in the plastic scintillators predominantly via the Compton effect, making the direct measurement of their energy impossible. Nevertheless, it is shown in this paper that the J-PET scanner will enable studies of the { o-Ps }→ 3γ decays with angular and energy resolution equal to σ (θ ) ≈ {0.4°} and σ (E) ≈ 4.1 {keV}, respectively. An order of magnitude shorter decay time of signals from plastic scintillators with respect to the inorganic crystals results not only in better timing properties crucial for the reduction of physical and instrumental background, but also suppresses significantly the pile-ups, thus enabling compensation of the lower efficiency of the plastic scintillators by performing measurements with higher positron source activities.

Investigations of surface coatings to reduce memory effect in plastic scintillator detectors used for radioxenon detection

Science.gov (United States)

Bläckberg, L.; Fay, A.; Jõgi, I.; Biegalski, S.; Boman, M.; Elmgren, K.; Fritioff, T.; Johansson, A.; Mårtensson, L.; Nielsen, F.; Ringbom, A.; Rooth, M.; Sjöstrand, H.; Klintenberg, M.

2011-11-01

In this work Al2O3 and SiO2 coatings are tested as Xe diffusion barriers on plastic scintillator substrates. The motivation is improved beta-gamma coincidence detection systems, used to measure atmospheric radioxenon within the verification regime of the Comprehensive Nuclear-Test-Ban Treaty. One major drawback with the current setup of these systems is that the radioxenon tends to diffuse into the plastic scintillator material responsible for the beta detection, resulting in an unwanted memory effect. Here, coatings with thicknesses between 20 and 900 nm have been deposited onto plastic scintillators, and investigated using two different experimental techniques. The results show that all tested coatings reduce the Xe diffusion into the plastic. The reduction is observed to increase with coating thickness for both coating materials. The 425 nm Al2O3 coating is the most successful one, presenting a diffusion reduction of a factor 100, compared to uncoated plastic. In terms of memory effect reduction this coating is thus a viable solution to the problem in question.

Investigations of surface coatings to reduce memory effect in plastic scintillator detectors used for radioxenon detection

International Nuclear Information System (INIS)

Blaeckberg, L.; Fay, A.; Jogi, I.; Biegalski, S.; Boman, M.; Elmgren, K.; Fritioff, T.; Johansson, A.; Martensson, L.; Nielsen, F.; Ringbom, A.; Rooth, M.; Sjoestrand, H.; Klintenberg, M.

2011-01-01

In this work Al 2 O 3 and SiO 2 coatings are tested as Xe diffusion barriers on plastic scintillator substrates. The motivation is improved beta-gamma coincidence detection systems, used to measure atmospheric radioxenon within the verification regime of the Comprehensive Nuclear-Test-Ban Treaty. One major drawback with the current setup of these systems is that the radioxenon tends to diffuse into the plastic scintillator material responsible for the beta detection, resulting in an unwanted memory effect. Here, coatings with thicknesses between 20 and 900 nm have been deposited onto plastic scintillators, and investigated using two different experimental techniques. The results show that all tested coatings reduce the Xe diffusion into the plastic. The reduction is observed to increase with coating thickness for both coating materials. The 425 nm Al 2 O 3 coating is the most successful one, presenting a diffusion reduction of a factor 100, compared to uncoated plastic. In terms of memory effect reduction this coating is thus a viable solution to the problem in question.

Detection of electrons in the 10 MeV range by plastic scintillators

Energy Technology Data Exchange (ETDEWEB)

Beaudoin, G; Champagne, A; Jeremie, H; Lessard, L

1986-09-10

Response functions for electrons from 1 to 12 MeV have been measured with a plastic scintillator telescope. A parametrization model for these response functions has been found to give good results at all energies. Furthermore it was established that the type of reflector used for the scintillator has a considerable influence on the response functions. A mechanism for this influence has been proposed and tested by Monte Carlo calculations.

Design of Fluorescent Compounds for Scintillation Detection

Energy Technology Data Exchange (ETDEWEB)

Pla-Dalmau, Anna [Northern Illinois U.

1990-01-01

Plastic scintillation detectors for high energy physics applications require the development of new fluorescent compounds to meet the demands set by the future generation of particle accelerators such as the Superconducting Supercollider (SSe). Plastic scintillators are commonly based on a polymer matrix doped with two fluorescent compounds: the primary dopant and the wavelength shifter. Their main characteristics are fast response time and high quantum efficiency. The exposure to larger radiation doses and demands for larger light output questions their survivability in the future experiments. A new type of plastic scintillator - intrinsic scintillator - has been suggested. It uses a single dopant as primary and wavelength shifter, and should be less susceptible to radiation damage....

Iterative Monte Carlo simulation with the Compton kinematics-based GEB in a plastic scintillation detector

Energy Technology Data Exchange (ETDEWEB)

Kim, Chankyu; Kim, Yewon [Department of Nuclear and Quantum Engineering, KAIST, Daejeon 305-701 (Korea, Republic of); Moon, Myungkook [Neutron Instrumentation Division, KAERI, Daejeon 305-353 (Korea, Republic of); Cho, Gyuseong, E-mail: gscho@kaist.ac.kr [Department of Nuclear and Quantum Engineering, KAIST, Daejeon 305-701 (Korea, Republic of)

2015-09-21

Plastic scintillators have been used for gamma ray detection in the fields of dosimetry and homeland security because of their desired characteristics such as a fast decay time, a low production cost, availability in a large-scale, and a tissue-equivalence. Gaussian energy broadening (GEB) in MCNP simulation is an effective treatment for tallies to calculate the broadened response function of a detector similarly to measured spectra. The full width at half maximum (FWHM) of a photopeak has been generally used to compute input parameters required for the GEB treatment. However, it is hard to find the photopeak in measured gamma spectra with plastic scintillators so that computation of the input parameters for the GEB has to be taken with another way. In this study, an iterative method for the GEB treated MCNP simulation to calculate the response function of a plastic scintillator is suggested. Instead of the photopeak, Compton maximum and Compton edge were used to estimate energy broadening in the measured spectra and to determine the GEB parameters. In a demonstration with a CsI(Tl) scintillator, the proposed iterative simulation showed the similar gamma spectra to the existing method using photopeaks. The proposed method was then applied to a polystyrene scintillator, and the simulation result were in agreement with the measured spectra with only a little iteration.

A feasibility study of ortho-positronium decays measurement with the J-PET scanner based on plastic scintillators

International Nuclear Information System (INIS)

Kaminska, D.; Gajos, A.; Czerwinski, E.; Alfs, D.; Bednarski, T.; Bialas, P.; Dulski, K.; Glowacz, B.; Gupta-Sharma, N.; Korcyl, G.; Krawczyk, N.; Kubicz, E.; Mohammed, M.; Niedzwiecki, Sz.; Pawlik-Niedzwiecka, M.; Rudy, Z.; Wieczorek, A.; Zielinski, M.; Moskal, P.; Curceanu, C.; Silarski, M.; Gorgol, M.; Jasinska, B.; Zgardzinska, B.; Hiesmayr, B.C.; Kowalski, P.; Raczynski, L.; Wislicki, W.; Krzemien, W.

2016-01-01

We present a study of the application of the Jagiellonian positron emission tomograph (J-PET) for the registration of gamma quanta from decays of ortho-positronium (o-Ps). The J-PET is the first positron emission tomography scanner based on organic scintillators in contrast to all current PET scanners based on inorganic crystals. Monte Carlo simulations show that the J-PET as an axially symmetric and high acceptance scanner can be used as a multi-purpose detector well suited to pursue research including e.g. tests of discrete symmetries in decays of ortho-positronium in addition to the medical imaging. The gamma quanta originating from o-Ps decay interact in the plastic scintillators predominantly via the Compton effect, making the direct measurement of their energy impossible. Nevertheless, it is shown in this paper that the J-PET scanner will enable studies of the o-Ps → 3γ decays with angular and energy resolution equal to σ(θ) ∼ 0.4 circle and σ(E) ∼ 4.1 keV, respectively. An order of magnitude shorter decay time of signals from plastic scintillators with respect to the inorganic crystals results not only in better timing properties crucial for the reduction of physical and instrumental background, but also suppresses significantly the pile-ups, thus enabling compensation of the lower efficiency of the plastic scintillators by performing measurements with higher positron source activities. (orig.)

A feasibility study of ortho-positronium decays measurement with the J-PET scanner based on plastic scintillators

Energy Technology Data Exchange (ETDEWEB)

Kaminska, D.; Gajos, A.; Czerwinski, E.; Alfs, D.; Bednarski, T.; Bialas, P.; Dulski, K.; Glowacz, B.; Gupta-Sharma, N.; Korcyl, G.; Krawczyk, N.; Kubicz, E.; Mohammed, M.; Niedzwiecki, Sz.; Pawlik-Niedzwiecka, M.; Rudy, Z.; Wieczorek, A.; Zielinski, M.; Moskal, P. [Jagiellonian University, Faculty of Physics, Astronomy and Applied Computer Science, Krakow (Poland); Curceanu, C.; Silarski, M. [INFN, Laboratori Nazionali di Frascati, CP 13, Frascati (Italy); Gorgol, M.; Jasinska, B.; Zgardzinska, B. [Maria Curie-Sklodowska University, Department of Nuclear Methods, Institute of Physics, Lublin (Poland); Hiesmayr, B.C. [University of Vienna, Faculty of Physics, Vienna (Austria); Kowalski, P.; Raczynski, L.; Wislicki, W. [Swierk Computing Centre, National Centre for Nuclear Research, Otwock-Swierk (Poland); Krzemien, W. [National Centre for Nuclear Research, High Energy Department, Otwock-Swierk (Poland)

2016-08-15

We present a study of the application of the Jagiellonian positron emission tomograph (J-PET) for the registration of gamma quanta from decays of ortho-positronium (o-Ps). The J-PET is the first positron emission tomography scanner based on organic scintillators in contrast to all current PET scanners based on inorganic crystals. Monte Carlo simulations show that the J-PET as an axially symmetric and high acceptance scanner can be used as a multi-purpose detector well suited to pursue research including e.g. tests of discrete symmetries in decays of ortho-positronium in addition to the medical imaging. The gamma quanta originating from o-Ps decay interact in the plastic scintillators predominantly via the Compton effect, making the direct measurement of their energy impossible. Nevertheless, it is shown in this paper that the J-PET scanner will enable studies of the o-Ps → 3γ decays with angular and energy resolution equal to σ(θ) ∼ 0.4 {sup circle} and σ(E) ∼ 4.1 keV, respectively. An order of magnitude shorter decay time of signals from plastic scintillators with respect to the inorganic crystals results not only in better timing properties crucial for the reduction of physical and instrumental background, but also suppresses significantly the pile-ups, thus enabling compensation of the lower efficiency of the plastic scintillators by performing measurements with higher positron source activities. (orig.)

A time - zero detector based on thin film plastic scintillator

International Nuclear Information System (INIS)

Petrovici, M.; Simion, V.; Pagano, A.; Urso, S.; Geraci, E.

1998-01-01

Thin film scintillator used as a fast time-zero detector exhibits some advantages: fast response, small energy loss of transmitted particles, insensitivity to radiation damage, high efficiency and high counting rate capability. In order to increase the efficiency of the light collection, the scintillating plastic foil is housed in a reflecting body having an ellipsoidal geometry. A concave ellipsoidal mirror has the property that the geometrical foci are optically conjugate points and consequently, all optical path lengths from one focus to the other via a single reflection are equal. With the thin scintillator foil situated at one focal point and the PM's photocathode at the other one, an excellent light collection can be obtained. The principle of detector and the main components are presented. For our purposes we constructed the detector in two variants: glass mirror and polished aluminium mirror. The semi-axes of the ellipsoidal profile are: a 49.8 mm, b = 34.2 mm for the glass mirror and a = 35 mm, b = 26.5 mm for the aluminium mirror, respectively. The diameter of the beam access hole on the both mirrors is 12 mm. The detectors are foreseen to be used at 4π detecting system CHIMERA for experiments with heavy ion beams at intermediate energies delivered by Superconducting Cyclotron from LNS - Catania. Presently, the performance of these detectors are tested using alpha radioactive sources and in-beam measurements. (authors)

High-pressure 3He-Xe gas scintillators for simultaneous detection of neutrons and gamma rays over a large energy range

International Nuclear Information System (INIS)

Tornow, W.; Esterline, J.H.; Leckey, C.A.; Weisel, G.J.

2011-01-01

We report on features of high-pressure 3 He-Xe gas scintillators which have not been sufficiently addressed in the past. Such gas scintillators can be used not only for the efficient detection of low-energy neutrons but at the same time for the detection and identification of γ-rays as well. Furthermore, 3 He-Xe gas scintillators are also very convenient detectors for fast neutrons in the 1-10 MeV energy range and for high-energy γ-rays in the 7-15 MeV energy range. Due to their linear pulse-height response and self calibration via the 3 He(n,p) 3 H reaction, neutron and γ-ray energies can easily be determined in this high-energy regime.

Optimization of mass of plastic scintillator film for flow-cell based tritium monitoring: a Monte Carlo study

International Nuclear Information System (INIS)

Roy, Arup Singha; Palani Selvam, T.; Raman, Anand; Raja, V.; Chaudhury, Probal

2014-01-01

Over the years, various types of tritium-in-air monitors have been designed and developed based on different principles. Ionization chamber, proportional counter and scintillation detector systems are few among them. A plastic scintillator based, flow-cell type online tritium-in-air monitoring system was developed for online monitoring of tritium in air. The value of the scintillator mass inside the cell-volume, which maximizes the response of the detector system, should be obtained to get maximum efficiency. The present study is aimed to optimize the amount of mass of the plastic scintillator film for the flow-cell based tritium monitoring instrument so that maximum efficiency is achieved. The Monte Carlo based EGSnrc code system has been used for this purpose

SPORT: A new sub-nanosecond time-resolved instrument to study swift heavy ion-beam induced luminescence - Application to luminescence degradation of a fast plastic scintillator

Science.gov (United States)

Gardés, E.; Balanzat, E.; Ban-d'Etat, B.; Cassimi, A.; Durantel, F.; Grygiel, C.; Madi, T.; Monnet, I.; Ramillon, J.-M.; Ropars, F.; Lebius, H.

2013-02-01

We developed a new sub-nanosecond time-resolved instrument to study the dynamics of UV-visible luminescence under high stopping power heavy ion irradiation. We applied our instrument, called SPORT, on a fast plastic scintillator (BC-400) irradiated with 27-MeV Ar ions having high mean electronic stopping power of 2.6 MeV/μm. As a consequence of increasing permanent radiation damages with increasing ion fluence, our investigations reveal a degradation of scintillation intensity together with, thanks to the time-resolved measurement, a decrease in the decay constant of the scintillator. This combination indicates that luminescence degradation processes by both dynamic and static quenching, the latter mechanism being predominant. Under such high density excitation, the scintillation deterioration of BC-400 is significantly enhanced compared to that observed in previous investigations, mainly performed using light ions. The observed non-linear behaviour implies that the dose at which luminescence starts deteriorating is not independent on particles' stopping power, thus illustrating that the radiation hardness of plastic scintillators can be strongly weakened under high excitation density in heavy ion environments.

Pulse shape discrimination using EJ-299-33 plastic scintillator coupled with a Silicon Photomultiplier array

International Nuclear Information System (INIS)

Liao, Can; Yang, Haori

2015-01-01

Recent developments in organic plastic scintillators capable of pulse shape discrimination (PSD) have gained much interest. Novel photon detectors, such as Silicon Photomultipliers (SiPMs), offer numerous advantages and can be used as an alternative to conventional photo multiplier tubes (PMTs) in many applications. In this work, we evaluate the PSD performance of the EJ-299-33 plastic scintillator coupled with a SiPM array. 2D PSD plots as well as the Figure of Merit (FOM) parameters are presented to demonstrate the PSD capability of EJ-299-33 using a SiPM as the light sensor. The best FOM of 0.76 was observed with a 1.0 MeVee (MeV-electron-equivalent) energy threshold, despite the high noise level of the SiPM array. A high-speed digital oscilloscope was used to acquire data, which was then processed offline in MATLAB. A performance comparison between two different PSD algorithms was carried out. The dependence of PSD quality on the sampling rate was also evaluated, stimulated by the interest to implement this setup for handheld applications where power consumption is crucial

Novel scintillating material 2-(4-styrylphenyl)benzoxazole for the fully digital and MRI compatible J-PET tomograph based on plastic scintillators.

Science.gov (United States)

Wieczorek, Anna; Dulski, Kamil; Niedźwiecki, Szymon; Alfs, Dominika; Białas, Piotr; Curceanu, Catalina; Czerwiński, Eryk; Danel, Andrzej; Gajos, Aleksander; Głowacz, Bartosz; Gorgol, Marek; Hiesmayr, Beatrix; Jasińska, Bożena; Kacprzak, Krzysztof; Kamińska, Daria; Kapłon, Łukasz; Kochanowski, Andrzej; Korcyl, Grzegorz; Kowalski, Paweł; Kozik, Tomasz; Krzemień, Wojciech; Kubicz, Ewelina; Kucharek, Mateusz; Mohammed, Muhsin; Pawlik-Niedźwiecka, Monika; Pałka, Marek; Raczyński, Lech; Rudy, Zbigniew; Rundel, Oleksandr; Sharma, Neha G; Silarski, Michał; Uchacz, Tomasz; Wiślicki, Wojciech; Zgardzińska, Bożena; Zieliński, Marcin; Moskal, Paweł

2017-01-01

A novel plastic scintillator is developed for the application in the digital positron emission tomography (PET). The novelty of the concept lies in application of the 2-(4-styrylphenyl)benzoxazole as a wavelength shifter. The substance has not been used as scintillator dopant before. A dopant shifts the scintillation spectrum towards longer wavelengths making it more suitable for applications in scintillators of long strips geometry and light detection with digital silicon photomultipliers. These features open perspectives for the construction of the cost-effective and MRI-compatible PET scanner with the large field of view. In this article we present the synthesis method and characterize performance of the elaborated scintillator by determining its light emission spectrum, light emission efficiency, rising and decay time of the scintillation pulses and resulting timing resolution when applied in the positron emission tomography. The optimal concentration of the novel wavelength shifter was established by maximizing the light output and it was found to be 0.05 ‰ for cuboidal scintillator with dimensions of 14 mm x 14 mm x 20 mm.

Detection of fast neutrons in a plastic scintillator using digital pulse processing to reject gammas

International Nuclear Information System (INIS)

Reeder, P.L.; Peurrung, A.J.; Hansen, R.R.; Stromswold, D.C.; Hensley, W.K.; Hubbard, C.W.

1999-01-01

We report on neutron-gamma discrimination in a plastic scintillator based on the time delay inherent in second and third chance neutron scattering. Because of the time delay (∼3 ns) between the first and second scattering of a neutron, calculations of gammas and neutrons in a plastic scintillator predict that a neutron signal should be significantly broader than a pulse from a gamma event. Experimentally, we have used a fast digital oscilloscope coupled to a computer to examine individual pulses from neutron or gamma induced signals in fast scintillators coupled to a fast PMT. Individual neutron-induced signals were consistent with the predictions of our model, but gamma pulses were broader than expected. We present various tests to understand this phenomenon and discuss a way to overcome this problem

A rod-like plastic scintillation detector for use in gamma-ray dosimetry and attempts to attain uniform response

International Nuclear Information System (INIS)

Yamashita, Mikio; Kawada, Yasushi; Avundukluoglu, M.A.

1989-01-01

The paper describes experiments made in an effort to develop scintillation dosimeters with emphasis on some attempts to attain a uniform response over the whole length of scintillators. A new method is proposed for measuring absorbed dose rate in plastic scintillators, using the photon-counting technique for measuring the total amount of luminescence from the scintillator exposed to gamma-rays. If a rod plastic scintillator and lucite light guides with well-polished and non-coated surfaces are surrounded by non-reflective material with a definite air gap between them, the scintillation light is transmitted to the PMTs only by the inner total reflection from the surface; a good uniformity of response could be expected if it were not for light attenuation in the transmission through the medium. With a diffusion reflector in non-optical contact with the scintillator surface, the scintillation light which otherwise would escape from the surface is partly reflected back into the scintillator. This effect is examined quantitatively. Measurements show that the presence of the diffusion reflector permits the uniformity of response to be improved considerably; a uniformity within 20 % is obtained. (N.K.)

A primary scintillation gated high pressure position sensitive gas scintillation proportional counter (HPGSPC) for applications to x-ray astronomy

International Nuclear Information System (INIS)

Giarrusso, S.; Manzo, G.; Re, S.

1985-01-01

The authors describe a new instrument for x-ray astronomy. The instrument, based on a high pressure (5 atm.), xenon filled, position sensitive Gas Scintillation Proportional counter (HPGSPC) is expected to feature an energy resolution better than 4% at 60 keV, an angular resolution of approximately 20 arc-minutes over the full energy range (4 to 100 keV) and a field of view (FOV) of up to 30x30 degrees. A prototype flight unit of the gas cell on which the instrument is based is presently under technological development in the framework of the SAX project

Alpha scintillation radon counting

International Nuclear Information System (INIS)

Lucas, H.F. Jr.

1977-01-01

Radon counting chambers which utilize the alpha-scintillation properties of silver activated zinc sulfide are simple to construct, have a high efficiency, and, with proper design, may be relatively insensitive to variations in the pressure or purity of the counter filling. Chambers which were constructed from glass, metal, or plastic in a wide variety of shapes and sizes were evaluated for the accuracy and the precision of the radon counting. The principles affecting the alpha-scintillation radon counting chamber design and an analytic system suitable for a large scale study of the 222 Rn and 226 Ra content of either air or other environmental samples are described. Particular note is taken of those factors which affect the accuracy and the precision of the method for monitoring radioactivity around uranium mines

The sensitivity calibration of the ultra-fast quench plastic scintillation detector for D-T neutrons

International Nuclear Information System (INIS)

Tang Changhuan; Yan Meiqiong; Xie Chaomei

1998-01-01

The authors introduce some characteristics of ultra-fast quench plastic scintillation detectors. When the detectors are composed of different scintillators, light guides and microchannel plate photomultiplier tube (MCP-PMT), their sensitivities to D-T neutrons are calibrated by a pulse neutron tube with a neutron pulse width about 10 ns

Plastic Deformation of Pressured Metallic Glass

Directory of Open Access Journals (Sweden)

Yun Cheng

2017-11-01

Full Text Available Although pressured metallic glass (MG has been reported in the literature; there are few studies focusing on pressure effects on the structure; dynamics and its plastic deformation. In this paper; we report on and characterize; via molecular dynamics simulation, the structure and dynamics heterogeneity of pressured MGs, and explore a causal link between local structures and plastic deformation mechanism of pressured glass. The results exhibit that the dynamical heterogeneity of metallic liquid is more pronounced at high pressure, while the MGs were less fragile after the release of external pressure, reflected by the non-Gaussian parameter (NGP. High pressure glass shows better plastic deformation; and the local strain zone distributed more uniformly than of in normal glass. Further research indicates that although the number of icosahedrons in pressured glass was much larger than that in normal glass, while the interpenetrating connections of icosahedra (ICOI exhibited spatial correlations were rather poor; In addition, the number of ‘fast’ atoms indexed by the atoms’ moving distance is larger than that in normal glass; leading to the sharp decreasing in number of icosahedrons during deformation. An uniform distribution of ‘fast’ atoms also contributed to better plastic deformation ability in the pressured glass. These findings may suggest a link between the deformation and destruction of icosahedra with short-range order.

Analysis of {sup 210}Pb in water samples with plastic scintillation resins

Energy Technology Data Exchange (ETDEWEB)

Lluch, E.; Barrera, J. [Department of Analytical Chemistry, University of Barcelona, Martí i Franqués, 1-11, E-08028, Barcelona (Spain); Tarancón, A., E-mail: alex.tarancon@ub.edu [Department of Analytical Chemistry, University of Barcelona, Martí i Franqués, 1-11, E-08028, Barcelona (Spain); Bagán, H. [Department of Pure and Applied Biochemistry, Lund University, Getingevägen 60, Hus II, 22100 SE, Lund (Sweden); García, J.F. [Department of Analytical Chemistry, University of Barcelona, Martí i Franqués, 1-11, E-08028, Barcelona (Spain)

2016-10-12

{sup 210}Pb is a radioactive lead isotope present in the environment as member of the {sup 238}U decay chain. Since it is a relatively long-lived radionuclide (T{sub 1/2} = 22.2 years), its analysis is of interest in radiation protection and the geochronology of sediments and artwork. Here, we present a method for analysing {sup 210}Pb using plastic scintillation resins (PSresins) packaged in solid-phase extraction columns (SPE cartridge). The advantages of this method are its selectivity, the low limit of detection, as well as reductions in the amount of time and reagents required for analysis and the quantity of waste generated. The PSresins used in this study were composed of a selective extractant (4′,4″(5″)-Di-tert-butyldicyclohexano-18-crown-6 in 1-octanol) covering the surface of plastic scintillation microspheres. Once the amount of extractant (1:1/4) and medium of separation (2 M HNO{sub 3}) were optimised, PSresins in SPE cartridges were calibrated with a standard solution of {sup 210}Pb. {sup 210}Pb could be fully separated from its daughters, {sup 210}Bi and {sup 210}Po, with a recovery value of 91(3)% and detection efficiency of 44(3)%. Three spiked water samples (one underground and two river water samples) were analysed in triplicates with deviations lower than 10%, demonstrating the validity of the PS resin method for {sup 210}Pb analysis. - Highlights: • A plastic scintillation resin for selective analysis of {sup 210}Pb has been developed. • A commercial SPE cartridge has been use for separation and scintillation counting. • {sup 210}Pb separation from {sup 210}Bi and {sup 210}Po is achieved with a 91(3)% of recovery. • The method is valid for analysis of {sup 210}Pb in river water samples.

Plastic scintillation detectors for dose monitoring in digital breast tomosynthesis

Science.gov (United States)

Antunes, J.; Machado, J.; Peralta, L.; Matela, N.

2018-01-01

Plastic scintillators detectors (PSDs) have been studied as dosimeters, since they provide a cost-effective alternative to conventional ionization chambers. Measurement and analysis of energy dependency were performed on a Siemens Mammomat tomograph for two different peak kilovoltages: 26 kV and 35 kV. Both PSD displayed good linearity for each energy considered and almost no energy dependence.

High-pressure {sup 3}He-Xe gas scintillators for simultaneous detection of neutrons and gamma rays over a large energy range

Energy Technology Data Exchange (ETDEWEB)

Tornow, W., E-mail: tornow@tunl.duke.edu [Department of Physics, Duke University, Durham, NC 27708 (United States); Triangle Universities Nuclear Laboratory, Durham, NC 27708 (United States); Esterline, J.H. [Department of Physics, Duke University, Durham, NC 27708 (United States); Triangle Universities Nuclear Laboratory, Durham, NC 27708 (United States); Leckey, C.A. [Department of Physics, The College of William and Mary, Williamsburg, VA 23187 (United States); Weisel, G.J. [Department of Physics, Penn State Altoona, Altoona, PA 16601 (United States)

2011-08-11

We report on features of high-pressure {sup 3}He-Xe gas scintillators which have not been sufficiently addressed in the past. Such gas scintillators can be used not only for the efficient detection of low-energy neutrons but at the same time for the detection and identification of {gamma}-rays as well. Furthermore, {sup 3}He-Xe gas scintillators are also very convenient detectors for fast neutrons in the 1-10 MeV energy range and for high-energy {gamma}-rays in the 7-15 MeV energy range. Due to their linear pulse-height response and self calibration via the {sup 3}He(n,p){sup 3}H reaction, neutron and {gamma}-ray energies can easily be determined in this high-energy regime.

Design and test of a scintillation dosimeter for dosimetry measurements of high energy radiotherapy beams

International Nuclear Information System (INIS)

Fontbonne, J.M.

2002-12-01

This work describes the design and evaluation of the performances of a scintillation dosimeter developed for the dosimetry of radiation beams used in radiotherapy. The dosimeter consists in a small plastic scintillator producing light which is guided by means of a plastic optical fiber towards photodetectors. In addition to scintillation, high energy ionizing radiations produce Cerenkov light both in the scintillator and the optical fiber. Based on a wavelength analysis, we have developed a deconvolution technique to measure the scintillation light in the presence of Cerenkov light. We stress the advantages that are anticipated from plastic scintillator, in particular concerning tissue or water equivalence (mass stopping power, mass attenuation or mass energy absorption coefficients). We show that detectors based on this material have better characteristics than conventional dosimeters such as ionisation chambers or silicon detectors. The deconvolution technique is exposed, as well as the calibration procedure using an ionisation chamber. We have studied the uncertainty of our dosimeter. The electronics noise, the fiber transmission, the deconvolution technique and the calibration errors give an overall combined experimental uncertainty of about 0,5%. The absolute response of the dosimeter is studied by means of depth dose measurements. We show that absolute uncertainty with photons or electrons beams with energies ranging from 4 MeV to 25 MeV is less than ± 1 %. Last, at variance with other devices, our scintillation dosimeter does not need dose correction with depth. (author)

Use of plastic scintillators for particle density measuring and their influence in the characterization of extensive atmospheric showers

International Nuclear Information System (INIS)

Biral, A.R.P.; Chinellato, J.A.; Fauth, A.C.; Kemp, E.; Oliveira, M.A. Leigui de; Manganote, E.J.T.; Nogima, H.; Rigitano, R.C.; Santos, L.G. dos; Silva, E.L.F.; Silva, N. Mengoti; Souza Junior, M.C.; Tamura, E.; Turtelli Junior, A.

1994-01-01

The use of plastic scintillators for particle density measuring and their influence in the characterization of extensive atmospheric showers has been studied.Using a experimental system coupled with a plastic scintillator detector with a 'streamer' tubes module, single muon events were selected through tracks rebuilding. The influence of those distributions in the determination of particle density and extensive atmospheric showers fundamental parameters were also studied. 10 refs., 2 figs

Test of a single module of the J-PET scanner based on plastic scintillators

International Nuclear Information System (INIS)

Moskal, P.; Niedźwiecki, Sz.; Bednarski, T.; Czerwiński, E.; Kapłon, Ł.; Kubicz, E.; Moskal, I.; Pawlik-Niedźwiecka, M.; Sharma, N.G.; Silarski, M.; Zieliński, M.; Zoń, N.; Białas, P.; Gajos, A.; Kochanowski, A.; Korcyl, G.; Kowal, J.; Kowalski, P.; Kozik, T.; Krzemień, W.

2014-01-01

A Time of Flight Positron Emission Tomography scanner based on plastic scintillators is being developed at the Jagiellonian University by the J-PET collaboration. The main challenge of the conducted research lies in the elaboration of a method allowing application of plastic scintillators for the detection of low energy gamma quanta. In this paper we report on tests of a single detection module built out from the BC-420 plastic scintillator strip (with dimensions of 5×19×300 mm 3 ) read out at two ends by Hamamatsu R5320 photomultipliers. The measurements were performed using collimated beam of annihilation quanta from the 68 Ge isotope and applying the Serial Data Analyzer (Lecroy SDA6000A) which enabled sampling of signals with 50 ps intervals. The time resolution of the prototype module was established to be better than 80 ps (σ) for a single level discrimination. The spatial resolution of the determination of the hit position along the strip was determined to be about 0.93 cm (σ) for the annihilation quanta. The fractional energy resolution for the energy E deposited by the annihilation quanta via the Compton scattering amounts to σ(E)/E≈0.044/√(E(MeV)) and corresponds to the σ(E)/E of 7.5% at the Compton edge

A capture-gated neutron calorimeter using plastic scintillators and 3He drift tubes

International Nuclear Information System (INIS)

Wang, Zhehui; Morris, Christopher L.; Spaulding, Randy J.; Bacon, Jeffrey D.; Borozdin, Konstantin N.; Chung, Kiwhan; Clark, Deborah J.; Green, Jesse A.; Greene, Steven J.; Hogan, Gary E.; Jason, Andrew; Lisowski, Paul W.; Makela, Mark F.; Mariam, Fessaha G.; Miyadera, Haruo; Murray, Matthew M.; Saunders, Alexander; Wysocki, Frederick J.; Gray, Frederick E.

2010-01-01

A segmented neutron calorimeter using nine 4-inch x 4-inch x 48-inch plastic scintillators and sixteen 2-inch-diameter 48-inch-long 200-mbar- 3 He drift tubes is described. The correlated scintillator and neutron-capture events provide a means for n/γ discrimination, critical to the neutron calorimetry when the γ background is substantial and the γ signals are comparable in amplitude to the neutron signals. A single-cell prototype was constructed and tested. It can distinguish between a 17 N source and a 252 Cf source when the γ and the thermal neutron background are sufficiently small. The design and construction of the nine-cell segmented detector assembly follow the same principle. By recording the signals from individual scintillators, additional γ-subtraction schemes, such as through the time-of-flight between two scintillators, may also be used. The variations of the light outputs from different parts of a scintillator bar are less than 10%.

A study of time over threshold (TOT) technique for plastic scintillator counter

International Nuclear Information System (INIS)

Wu Jinjie; Chinese Academy of Sciences, Beijing; Heng Yuekun; Sun Zhijia; Wu Chong; Yang Guian; Jiang Chun Hua; Zhao Yuda

2008-01-01

A new charge measurement method, time over threshold (TOT), has been used in some gas detectors lately. Here TOT is studied for TOF system, made of plastic scintillator counter, which can simplify the electronics of the system. The signal characteristics are measured and analyzed with a high quality oscilloscope, including noise, pedestal, signal amplitude, total charge, rise time and the correlation between them. The TOT and charge are related and can be fitted by some empirical formula. The charge measurement resolution by TOT is given and this will help the design of TOF electronics. (authors)

Recovery and permanent radiation damage of plastic scintillators at different dose rates

International Nuclear Information System (INIS)

Bicken, B.; Holm, U.; Marckmann, T.; Wick, K.; Rhode, M.

1990-01-01

This paper reports on the radiation stability of plastic scintillators and wavelength shifters for the calorimeter of the ZEUS detector by irradiating them with protons, a 60 Co-source, and depleted uranium. Changes in light yield, absorption length and absorption coefficient have been measured for storage in inert and oxygen atmospheres during and after irradiation. Radiation doses up to 40 kGy with dose rates of 30 up to 2000 Gy/h have been applied. The polystyrene based scintillator SCSN-38 and the wavelength shifters Y-7 and K-27 in PMMA show an additional absorption but a recovery in air to a low permanent damage (at 10 kGy) which is proportional to the applied dose. Series investigations on samples of all production cycles of the ZEUS scintillators with high dose rates show only minor differences in radiation hardness. The recovery is described by a simple oxygen diffusion model for high and medium dose rates down to 30 Gy/h. During long term irradiations at low dose rates (<100 Gy/h) of 3 mm thick SCSN-38 in air the radiation damage recovers to a permanent damage which does not depend on the dose rate. On the other hand the radiation damage at very low dose rates (17 Gy/a) seems to be higher than expected for the accumulated dose

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

International Nuclear Information System (INIS)

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

2007-11-01

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

TH-C-19A-10: Systematic Evaluation of Photodetectors Performances for Plastic Scintillation Dosimetry

International Nuclear Information System (INIS)

Boivin, J; Beaulieu, L; Beddar, S; Guillemette, M

2014-01-01

Purpose: To assess and compare the performance of different photodetectors likely to be used in a plastic scintillation detector (PSD). Methods: The PSD consists of a 1 mm diameter, 10 mm long plastic scintillation fiber (BCF-60) which is optically coupled to a clear 10 m long optical fiber of the same diameter. A light-tight plastic sheath covers both fibers and the scintillator end is sealed. The clear fiber end is connected to one of the following six studied photodetectors: two polychromatic cameras (one with an optical lens and one with a fiber optic taper replacing the lens); a monochromatic camera with the same optical lens; a PIN photodiode; an avalanche photodiode (APD); and a photomultiplier tube (PMT). Each PSD is exposed to both low energy beams (120, 180, and 220 kVp) from an orthovoltage unit, and high energy beams (6 MV and 23 MV) from a linear accelerator. Various dose rates are explored to identify the photodetectors operating ranges and accuracy. Results: For all photodetectors, the relative uncertainty remains under 5 % for dose rates over 3 mGy/s. The taper camera collects four times more signal than the optical lens camera, although its standard deviation is higher since it could not be cooled. The PIN, APD and PMT have higher sensitivity, suitable for low dose rate and out-of-field dose monitoring. PMT's relative uncertainty remains under 1 % at the lowest dose rate achievable (50 μGy/s), suggesting optimal use for live dosimetry. Conclusion: A set of 6 photodetectors have been studied over a broad dose rate range at various energies. For dose rate above 3 mGy/s, the PIN diode is the most effective photodetector in term of performance/cost ratio. For lower dose rate, such as those seen in interventional radiology, PMTs are the optimal choice. FQRNT Doctoral Research Scholarship

Energy dependent response of plastic scintillation detectors to photon radiation of low to medium energy.

Science.gov (United States)

Ebenau, Melanie; Radeck, Désirée; Bambynek, Markus; Sommer, Holger; Flühs, Dirk; Spaan, Bernhard; Eichmann, Marion

2016-08-01

Plastic scintillation detectors are promising candidates for the dosimetry of low- to medium-energy photons but quantitative knowledge of their energy response is a prerequisite for their correct use. The purpose of this study was to characterize the energy dependent response of small scintillation detectors (active volume <1 mm(3)) made from the commonly used plastic scintillator BC400. Different detectors made from BC400 were calibrated at a number of radiation qualities ranging from 10 to 280 kV and at a (60)Co beam. All calibrations were performed at the Physikalisch-Technische Bundesanstalt, the National Metrology Institute of Germany. The energy response in terms of air kerma, dose to water, and dose to the scintillator was determined. Conversion factors from air kerma to dose to water and to dose to the scintillator were derived from Monte Carlo simulations. In order to quantitatively describe the energy dependence, a semiempirical model known as unimolecular quenching or Birks' formula was fitted to the data and from this the response to secondary electrons generated within the scintillator material BC400 was derived. The detector energy response in terms of air kerma differs for different scintillator sizes and different detector casings. It is therefore necessary to take attenuation within the scintillator and in the casing into account when deriving the response in terms of dose to water from a calibration in terms of air kerma. The measured energy response in terms of dose to water for BC400 cannot be reproduced by the ratio of mean mass energy-absorption coefficients for polyvinyl toluene to water but shows evidence of quenching. The quenching parameter kB in Birks' formula was determined to be kB = (12.3 ± 0.9) mg MeV(-1) cm(-2). The energy response was quantified relative to the response to (60)Co which is the common radiation quality for the calibration of therapy dosemeters. The observed energy dependence could be well explained with the

Energy dependent response of plastic scintillation detectors to photon radiation of low to medium energy

Energy Technology Data Exchange (ETDEWEB)

Ebenau, Melanie, E-mail: melanie.ebenau@tu-dortmunde.de; Sommer, Holger; Spaan, Bernhard; Eichmann, Marion [Fakultät Physik, Technische Universität Dortmund, Otto-Hahn Str. 4a, 44221 Dortmund (Germany); Radeck, Désirée; Bambynek, Markus [Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig (Germany); Flühs, Dirk [Universitätsklinikum Essen, Hufelandstr. 55, 45147 Essen (Germany)

2016-08-15

Purpose: Plastic scintillation detectors are promising candidates for the dosimetry of low- to medium-energy photons but quantitative knowledge of their energy response is a prerequisite for their correct use. The purpose of this study was to characterize the energy dependent response of small scintillation detectors (active volume <1 mm{sup 3}) made from the commonly used plastic scintillator BC400. Methods: Different detectors made from BC400 were calibrated at a number of radiation qualities ranging from 10 to 280 kV and at a {sup 60}Co beam. All calibrations were performed at the Physikalisch-Technische Bundesanstalt, the National Metrology Institute of Germany. The energy response in terms of air kerma, dose to water, and dose to the scintillator was determined. Conversion factors from air kerma to dose to water and to dose to the scintillator were derived from Monte Carlo simulations. In order to quantitatively describe the energy dependence, a semiempirical model known as unimolecular quenching or Birks’ formula was fitted to the data and from this the response to secondary electrons generated within the scintillator material BC400 was derived. Results: The detector energy response in terms of air kerma differs for different scintillator sizes and different detector casings. It is therefore necessary to take attenuation within the scintillator and in the casing into account when deriving the response in terms of dose to water from a calibration in terms of air kerma. The measured energy response in terms of dose to water for BC400 cannot be reproduced by the ratio of mean mass energy-absorption coefficients for polyvinyl toluene to water but shows evidence of quenching. The quenching parameter kB in Birks’ formula was determined to be kB = (12.3 ± 0.9) mg MeV{sup −1} cm{sup −2}. Conclusions: The energy response was quantified relative to the response to {sup 60}Co which is the common radiation quality for the calibration of therapy dosemeters. The

Detection of gamma rays using scintillation optical fibers

International Nuclear Information System (INIS)

Park, J. W.; Hong, S. B.

2002-01-01

Scintillating optical fibers have several advantages over other conventional materials used for radiation detection. We have used glass and plastic scintillating fibers to detect gamma rays emitted from 60 Co and 137 Cs, and beta rays from 90 Sr. The sensors are constructed of single strand or multi-strand fibers of 1 mm diameter. The glass scintillating fiber used contains cerium-activated lithium-silicate as scintillating material and the plastic scintillating fiber used is Bicron model BCF-12. In this paper, we report the pulse-height spectra obtained by both sensor types, and analyze them in the aspect of their usability for radiation detectors. Our investigation suggests that the glass fiber can be used to develop gamma ray detectors which will function in high and low gamma ray flux environments. Use of the sensor for the beta ray detection was not satisfactory. The plastic fiber sensor did not work satisfactorily for the weak gamma sources, but did produce somewhat promising results. The scintillating plastic fiber offers some feasibility as beta ray sensor material

Design of A HPGe-Plastic Scintillator Compton Suppression Spectrometer for Neutron Activation Analysis and Radio environmental Studies

International Nuclear Information System (INIS)

Sharshar, T.; Badran, H.; Elnimr, T.

1998-01-01

The design of a compton suppression spectrometer consisting of a 10% p-type HPGe detector and an annular anti-Compton shield made of N E-102 A plastic scintillator is described. The height of the guard plastic- scintillation detector was optimized experimentally using a NaI(Ti) ring, consisting of five NaI(Ti) detectors. The annular guard detector is divided to four optically isolated quarters to enhance the light collection. Each quarter of the guard detector was tested and satisfying results are obtained

Evaluation of indigenously developed plastic scintillator sheet detector for surface radioactive contamination monitoring application

International Nuclear Information System (INIS)

Sahani, R.M.; Chaudhary, H.S.; Mahala, V.K.; Senwar, K.R.; Meena, J.P.

2018-01-01

Radioactive contamination may be caused by release of radioactivity in the environment due to accident at nuclear plant/reactor or spillage of loose radioactive materials in a laboratory. The protection of workers from potentially hazardous radiations emitted by the contaminants is a matter of prime concern. The detection of such radiations requires a monitoring system capable of measuring the level of radioactivity at the contaminated site. Plastic scintillators are widely used for large area radiation monitoring due to the ease of preparation in different shape and sizes. These detectors are sensitive to beta and gamma radiation therefore can be used for monitoring of beta and gamma contamination. In this paper, performance results of indigenously developed plastic scintillator sheet of area 800 cm 2 are reported

Clinical prototype of a plastic water-equivalent scintillating fiber dosimeter array for QA applications

International Nuclear Information System (INIS)

Lacroix, Frederic; Archambault, Louis; Gingras, Luc; Guillot, Mathieu; Beddar, A. Sam; Beaulieu, Luc

2008-01-01

A clinical prototype of a scintillating fiber dosimeter array for quality assurance applications is presented. The array consists of a linear array of 29 plastic scintillation detectors embedded in a water-equivalent plastic sheet coupled to optical fibers used to guide optical photons to a charge coupled device (CCD) camera. The CCD is packaged in a light-tight, radiation-shielded housing designed for convenient transport. A custom designed connector is used to ensure reproducible mechanical positioning of the optical fibers relative to the CCD. Profile and depth dose characterization measurements are presented and show that the prototype provides excellent dose measurement reproducibility (±0.8%) in-field and good accuracy (±1.6% maximum deviation) relative to the dose measured with an IC10 ionization chamber

Measurement of low-level beta activity of samples in liquid state using plastic scintillator vials

International Nuclear Information System (INIS)

Wezranowski, E.; Panczyk, E.; Radwan, M.

1977-01-01

Plastic scintillation vials having walls from a plastic scintillator and the bottom from perspex were used. Wall thickness was 0.8 to 3 mm. The solution radioactivity was measured by a scintillation beta spectrometer. The total measurement errors were found for the following radionuclides: 14 C +-3.7%; 204 Tl +-3%; 32 P +-2.8%; 137 Cs +-2%, and 72 Ga +-5%. Detection efficiency was found to decrease rapidly with the solution layer thickness. For a solution thickness of 0.2 mm the highest detection efficiency was observed with the 4% measurement error. Linear dependence was found of detection efficiency on beta energy. For a solution layer thickness of 0.2 mm the minimum measurable activities were determined to be 30.3 pCi for 14 C and 2.12 pCi for 32 P. The use of the above vials permits quick and simple measurement without sample chemical preparation. (J.P.)

Evaluation of NaI(TL) and plastic scintillators for use in remote, unattended, and portal monitoring

International Nuclear Information System (INIS)

Staples, P.; Audia, J.; Bai, Y.; Briggs, M.; Halbig, J.K.; Ianakiev, K.D.

1998-01-01

The authors have evaluated and compared some of the relevant operating characteristics of NaI and plastic scintillators for use in various safeguards monitoring applications. These include a sensitivity analysis of the two scintillators to various radiation fields and scintillator response as affected by environmental temperature. A comparison of experiment and modeling via the Monte Carlo N-Particle (MCNP) code has been performed to validate the calculational techniques. This then enables complex detector situations to be simulated with increased confidence

Test of a single module of the J-PET scanner based on plastic scintillators

Science.gov (United States)

Moskal, P.; Niedźwiecki, Sz.; Bednarski, T.; Czerwiński, E.; Kapłon, Ł.; Kubicz, E.; Moskal, I.; Pawlik-Niedźwiecka, M.; Sharma, N. G.; Silarski, M.; Zieliński, M.; Zoń, N.; Białas, P.; Gajos, A.; Kochanowski, A.; Korcyl, G.; Kowal, J.; Kowalski, P.; Kozik, T.; Krzemień, W.; Molenda, M.; Pałka, M.; Raczyński, L.; Rudy, Z.; Salabura, P.; Słomski, A.; Smyrski, J.; Strzelecki, A.; Wieczorek, A.; Wiślicki, W.

2014-11-01

A Time of Flight Positron Emission Tomography scanner based on plastic scintillators is being developed at the Jagiellonian University by the J-PET collaboration. The main challenge of the conducted research lies in the elaboration of a method allowing application of plastic scintillators for the detection of low energy gamma quanta. In this paper we report on tests of a single detection module built out from the BC-420 plastic scintillator strip (with dimensions of 5×19×300 mm3) read out at two ends by Hamamatsu R5320 photomultipliers. The measurements were performed using collimated beam of annihilation quanta from the 68Ge isotope and applying the Serial Data Analyzer (Lecroy SDA6000A) which enabled sampling of signals with 50 ps intervals. The time resolution of the prototype module was established to be better than 80 ps (σ) for a single level discrimination. The spatial resolution of the determination of the hit position along the strip was determined to be about 0.93 cm (σ) for the annihilation quanta. The fractional energy resolution for the energy E deposited by the annihilation quanta via the Compton scattering amounts to σ(E) / E ≈ 0.044 /√{ E(MeV) } and corresponds to the σ(E) / E of 7.5% at the Compton edge.

Comparison between some determination methods of residual styrene in plastic scintillators

International Nuclear Information System (INIS)

Bezuglyi, V.D.; Ponomarev, Yu.P.; Gunder, O.A.; Biteman, V.B.; Senchishin, V.G.

1988-01-01

Scintillators made of plastic materials based on polystyrene with addition of p-terphenyl and 1,4-di-[(2,5-phenyl)oxazolyl] benzene have found wide application principally in the detection of radioactivity. The stability of the scintillating characteristics of these materials depends to great degree on the concentration of the residual monomer and for this reason it is important to have a sufficiently convenient method for the determination of this latter. We investigated the bromometric and acid-base titration methods with visual and potentiometric titration end point detection. We also examined the polarographic methods, direct and indirect, using the electroreduction of the mercury acetate complex of the monomer. We checked the methods on a scintillator sample and on synthetic mixtures, i.e., mixtures of monomer, polymer, and p-terphenyl. We compared the determination results for styrene and showed that the most accurate procedure is the bromometric determination with potentiometric indication of the end-point

Scintillator manufacture at Fermilab

Energy Technology Data Exchange (ETDEWEB)

Mellott, K.; Bross, A.; Pla-Dalmau, A.

1998-08-01

A decade of research into plastic scintillation materials at Fermilab is reviewed. Early work with plastic optical fiber fabrication is revisited and recent experiments with large-scale commercial methods for production of bulk scintillator are discussed. Costs for various forms of scintillator are examined and new development goals including cost reduction methods and quality improvement techniques are suggested.

SU-E-T-782: Using Light Output From Doped Plastic Scintillators to Resolve the Linear Energy Transfer Spectrum of Clinical Electron Beams

International Nuclear Information System (INIS)

Nusrat, H; Pang, G; Ahmad, S; Keller, B; Sarfehnia, A

2015-01-01

Purpose: This research seeks to develop a portable, clinically-suitable linear energy transfer (LET) detector. In radiotherapy, absorbed dose is commonly used to measure the amount of delivered radiation, though, it is not a good indicator of actual biological damage. LET is the energy absorbed per unit length by a medium along charged particle’s pathway; studies have shown that LET correlates well with relative biological effectiveness (RBE). Methods: According to Birks’ law, light output of plastic scintillators is stopping-power dependent. This dependency can be varied through doping by various high-Z elements. By measuring light output signals of differently doped plastic scintillators (represented by column vector S, where each row corresponds to different scintillator material), the fluence of charged particles of a given LET (represented by column vector Φ, where each row corresponds to different LET bins) can be unfolded by S=R*Φ where R is system response matrix (each row represents a different scintillator, each column corresponds to different electron LET). Monte Carlo (MC) GEANT4.10.1 was used to evaluate ideal detector response of BC408 scintillating material doped with various concentrations of several high Z dopants. Measurements were performed to validate MC. Results: Signal for 1%-lead doped BC408 and the non-doped scintillator was measured experimentally by guiding light emitted by the scintillator (via in-house made taper, fiber system) to a PMT and then an electrometer. Simulations of 1%Pb-doped scintillator to non-doped scintillator revealed 9.3% reduction in light output for 6 MeV electrons which compared well (within uncertainty) with measurements showing 10% reduction (6MeV electrons). Conclusion: Measurements were used to validate MC simulation of light output from doped scintillators. The doping of scintillators is a viable technique to induce LET dependence. Our goal is to use this effect to resolve the LET spectrum of an incident

The characteristic calibration of the plastic scintillation detector for neutron diagnostic

CERN Document Server

Chen Hong Su

2002-01-01

The author presents the characteristic of the plastic scintillation detector used for pulse neutron diagnostic. The detection efficiency and sensitivity of the detector to DT neutron have been calibrated by the K-400 accelerator and by the pulse neutron tube, separately. The detection efficiency from the experiment is in agreement with that from calculation in the range of experimental errors

Proton beam dosimetry: a comparison between a plastic scintillator, ionization chamber and faraday cup

International Nuclear Information System (INIS)

Ghergherehchi, Mitra; Afarideh, Hossein; Mohammadzadeh, Ahmad; Boghrati, Behzad; Ghannadi, Mohammad; Aslani, Golam Reza

2010-01-01

In this study, a comparison was made between a plastic scintillator (BC400), a Faraday Cup (FC) and an ionization chamber (IC) used for routine proton dosimetry. Thin scintillators can be applied to proton dosimetry and consequently to proton therapy as relative dosimeters because of their water-equivalent nature, high energy-light conversion efficiency, low dimensions and good proportionality to the absorbed dose at low stopping powers. To employ such scintillators as relative dosimeters in proton therapy, the corrective factors must be applied to correct the quenching luminescence at the Bragg peak. A fine linear proportionality between the luminescence light yield Y and the proton flux in a thin (0.5 mm) scintillator for the 20 and 30 MeV proton beams were observed. The experimental peak/plateau ratios of Bragg Curve for 2, 1 and 0.5 mm scintillators with an accuracy of 0.5% were obtained to be 1.87, 1.91 and 2.30, respectively. With combination of the Markus chamber and the CR-39 detector, the peak/plateau ratio was improved to 3.26. The obtained data of the luminescence yield as a function of the specific energy loss is in agreement with the Craun-Birk's theory. Results show that the FC and Markus ionization chamber are in agreement within 4%, while the FC gives a lower dose evaluation. For a defined beam, the data for the fluence measurements are reproducible within a good accuracy. (author)

Scanners for the quality contol of scintillating plastic fibres

CERN Document Server

Rodigues, Ana Barbara; Garnier, Francois; Giudici, Pierre-Ange; Greim, Roman; Hebler, Philip; Joram, Christian; Kirn, Thomas; Pierschel, Gerhard; Schateikis, Tobias; Stevens, Holger; Bachlechner, Andreas; Deckenhoff, Mirco; Karpinski, Waclaw; Kruse, Florian; Schultz Von Dratzig, Arndt; Schwering, Georg; Swientek, Krzysztof Piotr; Wlochal, Michael

2015-01-01

The use of scintillating plastic fibres in the SciFi tracker requires rigorous quality control. The fibre diameter and in particular local variations in form of bumps and necks have an impact on the regularity of the winding pattern and hence the spatial resolution. Defects in the fibre cladding lead to light losses and inter-fibre cross talk. Machines have been developed which allow scanning at high throughput of the fibre diameter and the integrity of the cladding. We describe the design principles and implementations of these machines and illustrate their performance. While these machines allow to identify and quantify performance issues of the prototype fibres, they will also play a major role during the series production of the SciFi tracker. If needed, the capacity of the machines allows scanning of the full production volume.

A new anti-neutrino detection technique based on positronium tagging with plastic scintillators

Energy Technology Data Exchange (ETDEWEB)

Consolati, G. [Department of Aerospace Science and Technology, Politecnico di Milano, via La Masa 34, 20156 Milano (Italy); Franco, D., E-mail: dfranco@in2p3.fr [APC, Univ. Paris Diderot, CNRS/IN2P3, CEA/Irfu, Obs. de Paris, Sorbonne Paris Cité, 75205 Paris (France); Jollet, C. [IPHC, Université de Strasbourg, CNRS/IN2P3, 67037 Strasbourg (France); Meregaglia, A., E-mail: amerega@in2p3.fr [IPHC, Université de Strasbourg, CNRS/IN2P3, 67037 Strasbourg (France); Minotti, A. [IPHC, Université de Strasbourg, CNRS/IN2P3, 67037 Strasbourg (France); Perasso, S.; Tonazzo, A. [APC, Univ. Paris Diderot, CNRS/IN2P3, CEA/Irfu, Obs. de Paris, Sorbonne Paris Cité, 75205 Paris (France)

2015-09-21

The main signature for anti-neutrino detection in reactor and geo-neutrino experiments based on scintillators is provided by the space–time coincidence of positron and neutron produced in the Inverse Beta Decay reaction. Such a signature strongly suppresses backgrounds and allows for measurements performed underground with a relatively high signal-to-background ratio. In an aboveground environment, however, the twofold coincidence technique is not sufficient to efficiently reject the high background rate induced by cosmogenic events. Enhancing the positron–neutron twofold coincidence efficiency may pave the way to future aboveground detectors for reactor monitoring. We propose a new detection scheme based on a threefold coincidence, among the positron ionization, the ortho-positronium (o-Ps) decay, and the neutron capture, in a sandwich detector with alternated layers of plastic scintillator and aerogel powder. We present the results of a set of dedicated measurements on the achievable light yield and on the o-Ps formation and lifetime. The efficiencies for signal detection and background rejection of a preliminary detector design are also discussed.

Neutron-gamma discrimination via PSD plastic scintillator and SiPMs

Science.gov (United States)

Taggart, M. P.; Payne, C.; Sellin, P. J.

2016-10-01

The reduction in availability and inevitable increase in cost of traditional neutron detectors based on the 3He neutron capture reaction has resulted in a concerted effort to seek out new techniques and detection media to meet the needs of national nuclear security. Traditionally, the alternative has been provided through pulse shape discrimination (PSD) using liquid scintillators. However, these are not without their own inherent issues, primarily concerning user safety and ongoing maintenance. A potential system devised to separate neutron and gamma ray pulses utilising the PSD technique takes advantage of recent improvements in silicon photomultiplier (SiPM) technology and the development of plastic scintillators exhibiting the PSD phenomena. In this paper we present the current iteration of this ongoing work having achieved a Figure of Merit (FoM) of 1.39 at 1.5 MeVee.

Crosslinked plastic scintillators: A new detection system for radioactivity measurement in organic and aggressive media

International Nuclear Information System (INIS)

Bagán, Héctor; Tarancón, Alex; Ye, Lei; García, José F.

2014-01-01

Highlights: • A crosslinked plastic scintillatior for radioactivity measurement was developed. • The effect of C-PS composition in the detection efficiency was evaluated. • C-PS permits the measurement of radioactivity in organic and aggressive media. • C-PS exhibits high detection efficiency in water and even higher in organic media. • C-PS exhibits good reproducibility under different polymerisations with elevated yield. - Abstract: The measurement of radioactive solutions containing organic or aggressive media may cause stability problems in liquid and plastic scintillation (PS) techniques. In the case of PS, this can be overcome by adding a crosslinker to the polymer structure. The objectives of this study are to synthesise a suitable crosslinked plastic scintillator (C-PS) for radioactivity determination in organic and aggressive media. The results indicated that an increase in the crosslinker content reduces the detection efficiency and a more flexible crosslinker yields higher detection efficiency. For the polymer composition studied, 2,5-diphenyloxazole (PPO) is the most adequate fluorescent solute and an increase in its concentration causes little change in the detection efficiency. The inclusion of a secondary fluorescent solute 1,4-bis-2-(5-phenyloxazolyl) benzene (POPOP) improves the C-PS radiometrical characteristics. For the final composition chosen, the synthesis of the C-PS exhibits good reproducibility with elevated yield. The obtained C-PS also displays high stability in different organic (toluene, hydrotreated vegetable oil (HVO) and methanol) and aggressive media (hydrochloric acid, nitric acid and hydrogen peroxide). Finally, the C-PS exhibits high detection efficiency both in water and in aggressive media and can also be applied in organic media showing similar or even higher detection efficiency values

Alpha/beta pulse shape discrimination in plastic scintillation using commercial scintillation detectors

International Nuclear Information System (INIS)

Bagan, H.; Tarancon, A.; Rauret, G.; Garcia, J.F.

2010-01-01

Activity determination in different types of samples is a current need in many different fields. Simultaneously analysing alpha and beta emitters is now a routine option when using liquid scintillation (LS) and pulse shape discrimination. However, LS has an important drawback, the generation of mixed waste. Recently, several studies have shown the capability of plastic scintillation (PS) as an alternative to LS, but no research has been carried out to determine its capability for alpha/beta discrimination. The objective of this study was to evaluate the capability of PS to discriminate alpha/beta emitters on the basis of pulse shape analysis (PSA). The results obtained show that PS pulses had lower energy than LS pulses. As a consequence, a lower detection efficiency, a shift to lower energies and a better discrimination of beta and a worst discrimination of alpha disintegrations was observed for PS. Colour quenching also produced a decrease in the energy of the particles, as well as the effects described above. It is clear that in PS, the discrimination capability was correlated with the energy of the particles detected. Taking into account the discrimination capabilities of PS, a protocol for the measurement and the calculation of alpha and beta activities in mixtures using PS and commercial scintillation detectors has been proposed. The new protocol was applied to the quantification of spiked river water samples containing a pair of radionuclides ( 3 H- 241 Am or 90 Sr/ 90 Y- 241 Am) in different activity proportions. The relative errors in all determinations were lower than 7%. These results demonstrate the capability of PS to discriminate alpha/beta emitters on the basis of pulse shape and to quantify mixtures without generating mixed waste.

Bis(pinacolato)diboron as an additive for the detection of thermal neutrons in plastic scintillators

Energy Technology Data Exchange (ETDEWEB)

Mahl, Adam [Department of Physics and the Nuclear Science and Engineering Center (NuSEC), Colorado School of Mines, Golden, CO 80401 (United States); Yemam, Henok A.; Stuntz, John [Department of Chemistry and Geochemistry and the Materials Science Program Colorado School of Mines, Golden, CO 80401 (United States); Remedes, Tyler [Department of Physics and the Nuclear Science and Engineering Center (NuSEC), Colorado School of Mines, Golden, CO 80401 (United States); Sellinger, Alan [Department of Chemistry and Geochemistry and the Materials Science Program Colorado School of Mines, Golden, CO 80401 (United States); Greife, Uwe, E-mail: ugreife@mines.edu [Department of Physics and the Nuclear Science and Engineering Center (NuSEC), Colorado School of Mines, Golden, CO 80401 (United States)

2016-04-21

A readily available and inexpensive boron compound was tested as an additive for the detection of thermal neutrons in plastic scintillators. Bis(pinacolato)diboron (B{sub 2}Pin{sub 2}) was determined to be a compatible boron source (8.51 wt% boron, 1.70 wt% {sup 10}B) in poly(vinyltoluene) based matrices. Plastic scintillator blends of 1–20 wt% 2,5-diphenyloxazole (PPO), 0.1 wt% 1,4-bis(5-phenyloxazol-2-yl) benzene (POPOP) and 1–15 wt% B{sub 2}Pin{sub 2} were prepared that provided optical clarity, good mechanical properties, and the capability of thermal neutron detection. Independent of B{sub 2}Pin{sub 2} concentration, strong {sup 10}B neutron capture signals around 90 keV{sub ee} were observed at essentially constant light output. Increasing PPO concentration allowed for the use of pulse shape discrimination (PSD) in both fast and thermal neutron detection. High PPO concentrations appear to cause additional alpha quenching that affected the {sup 10}B neutron capture signal. Aging effects after storage in air for several months were observed, which led to degradation of performance and in some samples of mechanical stability.

Bis(pinacolato)diboron as an additive for the detection of thermal neutrons in plastic scintillators

International Nuclear Information System (INIS)

Mahl, Adam; Yemam, Henok A.; Stuntz, John; Remedes, Tyler; Sellinger, Alan; Greife, Uwe

2016-01-01

A readily available and inexpensive boron compound was tested as an additive for the detection of thermal neutrons in plastic scintillators. Bis(pinacolato)diboron (B_2Pin_2) was determined to be a compatible boron source (8.51 wt% boron, 1.70 wt% "1"0B) in poly(vinyltoluene) based matrices. Plastic scintillator blends of 1–20 wt% 2,5-diphenyloxazole (PPO), 0.1 wt% 1,4-bis(5-phenyloxazol-2-yl) benzene (POPOP) and 1–15 wt% B_2Pin_2 were prepared that provided optical clarity, good mechanical properties, and the capability of thermal neutron detection. Independent of B_2Pin_2 concentration, strong "1"0B neutron capture signals around 90 keV_e_e were observed at essentially constant light output. Increasing PPO concentration allowed for the use of pulse shape discrimination (PSD) in both fast and thermal neutron detection. High PPO concentrations appear to cause additional alpha quenching that affected the "1"0B neutron capture signal. Aging effects after storage in air for several months were observed, which led to degradation of performance and in some samples of mechanical stability.

Multiple scattering effects in fast neutron polarization experiments using high-pressure helium-xenon gas scintillators as analyzers

International Nuclear Information System (INIS)

Tornow, W.; Mertens, G.

1977-01-01

In order to study multiple scattering effects both in the gas and particularly in the solid materials of high-pressure gas scintillators, two asymmetry experiments have been performed by scattering of 15.6 MeV polarized neutrons from helium contained in stainless steel vessels of different wall thicknesses. A monte Carlo computer code taking into account the polarization dependence of the differential scattering cross sections has been written to simulate the experiments and to calculate corrections for multiple scattering on helium, xenon and the gas containment materials. Besides the asymmetries for the various scattering processes involved, the code yields time-of-flight spectra of the scattered neutrons and pulse height spectra of the helium recoil nuclei in the gas scintillator. The agreement between experimental results and Monte Carlo calculations is satisfactory. (Auth.)

Application of a free parameter model to plastic scintillation samples

Energy Technology Data Exchange (ETDEWEB)

Tarancon Sanz, Alex, E-mail: alex.tarancon@ub.edu [Departament de Quimica Analitica, Universitat de Barcelona, Diagonal 647, E-08028 Barcelona (Spain); Kossert, Karsten, E-mail: Karsten.Kossert@ptb.de [Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig (Germany)

2011-08-21

In liquid scintillation (LS) counting, the CIEMAT/NIST efficiency tracing method and the triple-to-double coincidence ratio (TDCR) method have proved their worth for reliable activity measurements of a number of radionuclides. In this paper, an extended approach to apply a free-parameter model to samples containing a mixture of solid plastic scintillation microspheres and radioactive aqueous solutions is presented. Several beta-emitting radionuclides were measured in a TDCR system at PTB. For the application of the free parameter model, the energy loss in the aqueous phase must be taken into account, since this portion of the particle energy does not contribute to the creation of scintillation light. The energy deposit in the aqueous phase is determined by means of Monte Carlo calculations applying the PENELOPE software package. To this end, great efforts were made to model the geometry of the samples. Finally, a new geometry parameter was defined, which was determined by means of a tracer radionuclide with known activity. This makes the analysis of experimental TDCR data of other radionuclides possible. The deviations between the determined activity concentrations and reference values were found to be lower than 3%. The outcome of this research work is also important for a better understanding of liquid scintillation counting. In particular the influence of (inverse) micelles, i.e. the aqueous spaces embedded in the organic scintillation cocktail, can be investigated. The new approach makes clear that it is important to take the energy loss in the aqueous phase into account. In particular for radionuclides emitting low-energy electrons (e.g. M-Auger electrons from {sup 125}I), this effect can be very important.

Prototype apparatus for the measurement of tritium in expired air using plastic scintillator pellets.

Science.gov (United States)

Furuta, Etsuko; Ito, Takeshi

2018-02-01

A new apparatus for measuring tritiated water in expired air was developed using plastic scintillator (PS) pellets and a low-background liquid scintillation counter. The sensitivity of the apparatus was sufficient when a large adapted Teflon vial was used. The measurement method generated low amounts of organic waste because the PS pellets were reusable by rinsing, and had adequate detection limits. The apparatus is useful for the safety management of workers that are exposed to radioactive materials. Copyright © 2017 Elsevier Ltd. All rights reserved.

Characterization of scintillating plastic fibers and silicon photomultipliers for their usage in a particle telescope

Energy Technology Data Exchange (ETDEWEB)

Pruefer, Lea; Losekamm, Martin; Poeschl, Thomas; Greenwald, Daniel; Paul, Stephan [Technische Universitaet Muenchen, 85748 Garching (Germany)

2016-07-01

The Multi-purpose Active-target Particle Telescope (MAPT) is a newly developed compact charged-particle detector. It can be used for space applications, such as radiation monitoring on spacecraft or for stratospheric research balloons. Its core consists of scintillating plastic fibers coupled to silicon photomultiplier (SiPMs). The energy reconstruction of the incoming particles is based on an extended Bragg curve spectroscopy technique, requiring a good measurement of the energy deposition. Therefore, non-linearities of the measured light output -such as quenching effects of the scintillating material or saturation of the SiPMs at high light yields- have to be known quantitatively. To investigate these effects, two scaled-down prototypes were built, consisting of 128 and 16 channels. The first one was tested at a stationary proton beam at Paul Scherrer Institute. We determine Birk's coefficient describing the ionization quenching of the scintillator and calculate the characteristic photon detection efficiency of the SiPMs. We explain the results of the first prototype tests and the characterization of the SiPMs.

New liquid scintillators for fiber-optic applications

International Nuclear Information System (INIS)

Lutz, S.S.; Franks, L.A.; Flournoy, J.M.; Lyons, P.B.

1981-01-01

New long-wavelength-emitting, high-speed, liquid scintillators have been developed and tailored specifically for plasma diagnostic experiments employing fiber optics. These scintillators offer significant advantages over commercially available plastic scintillators in terms of sensitivity and bandwidth. FWHM response times as fast as 350 ps have been measured. Emission spectra, time response data, and relative sensitivity information are presented

Neutron detection and multiplicity counting using a boron-loaded plastic scintillator/bismuth germanate phoswich detector array

International Nuclear Information System (INIS)

Miller, M.C.

1998-03-01

Neutron detection and multiplicity counting has been investigated using a boron-loaded plastic scintillator/bismuth germanate phoswich detector array. Boron-loaded plastic combines neutron moderation (H) and detection ( 10 B) at the molecular level, thereby physically coupling increasing detection efficiency and decreasing die-away time with detector volume. Both of these characteristics address a fundamental limitation of thermal-neutron multiplicity counters, where 3 He proportional counters are embedded in a polyethylene matrix. Separation of the phoswich response into its plastic scintillator and bismuth germanate components was accomplished on a pulse-by-pulse basis using custom integrator and timing circuits. In addition, a custom time-tag module was used to provide a time for each detector event. Analysis of the combined energy and time event stream was performed by calibrating each detector's response and filtering based on the presence of a simultaneous energy deposition corresponding to the 10 B(n,alpha) reaction products in the plastic scintillator (93 keV ee ) and the accompanying neutron-capture gamma ray in the bismuth germanate (478 keV). Time-correlation analysis was subsequently performed on the filtered event stream to obtain shift-register-type singles and doubles count rates. Proof-of-principle measurements were conducted with a variety of gamma-ray and neutron sources including 137 Cs, 54 Mn, AmLi, and 252 Cf. Results of this study indicate that a neutron-capture probability of ∼10% and a die-away time of ∼10 micros are possible with a 4-detector array with a detector volume of 1600 cm 3 . Simulations were performed that indicate neutron-capture probabilities on the order of 50% and die-away times of less than 4 micros are realistically achievable. While further study will be required for practical application of such a detection system, the results obtained in this investigation are encouraging and may lead to a new class of high

Design, building and evaluation of a neutron detection device based on boron loaded plastic scintillator

International Nuclear Information System (INIS)

Normand, St.

2001-10-01

This work focuses on the study, the characterization and the fabrication of Boron-loaded plastic scintillators. Their use in thermal and fast neutron detection devices is also investigated. Fabrication process, especially boron doping, is explained in the first part of this work. Several FTIR, UV-visible and NMR analysis methods were used in order to characterize the material and to check its structure and stoichiometry. Experiences were done using alpha particles and proton beams to measure the scintillation characteristics. Light emission could therefore be completely determined by the Birks semi-empirical relation. In the second part, the whole detector simulation is undergone: interaction between material and radiation, light generation, paths and signal generation. Neutron simulation by MCNP (Monte Carlo N-Particles) is coupled to a light generation and propagation code developed especially during this work. These simulation tools allow us to optimize the detector geometry for neutron detection and to determine the geometry influence to the photon collection efficiency. Neutron detection efficiency and mean lifetime in this scintillator are also simulated. The close fit obtained between experimental measurements and simulations demonstrate the reliability of the method used. The third part deals with the discrimination methods between neutron and gamma, such as analog (zero crossing) and digital (charge comparison) ones. Their performances were explained and compared. The last part of this work reports on few applications where neutron detection is essential and can be improved with the use of boron loaded plastic scintillators. In particular, the cases of doped scintillation fibers, neutron spectrometry devices and more over neutron multiplicity counting devices are presented. (author)

Time dispersion in large plastic scintillation neutron detector [Paper No.:B3

International Nuclear Information System (INIS)

De, A.; Dasgupta, S.S.; Sen, D.

1993-01-01

Time dispersion seen by photomultiplier (PM) tube in large plastic scintillation neutron detector and the light collection mechanism by the same have been computed showing that this time dispersion (TD) seen by the PM tube does not necessarily increase with increasing incident neutron energy in contrast to the usual finding that TD increases with increasing energy. (author). 8 refs., 4 figs

Thermally induced processes in mixtures of aluminum with organic acids after plastic deformations under high pressure

Science.gov (United States)

Zhorin, V. A.; Kiselev, M. R.; Roldugin, V. I.

2017-11-01

DSC is used to measure the thermal effects of processes in mixtures of solid organic dibasic acids with powdered aluminum, subjected to plastic deformation under pressures in the range of 0.5-4.0 GPa using an anvil-type high-pressure setup. Analysis of thermograms obtained for the samples after plastic deformation suggests a correlation between the exothermal peaks observed around the temperatures of degradation of the acids and the thermally induced chemical reactions between products of acid degradation and freshly formed surfaces of aluminum particles. The release of heat in the mixtures begins at 30-40°C. The thermal effects in the mixtures of different acids change according to the order of acid reactivity in solutions. The extreme baric dependences of enthalpies of thermal effects are associated with the rearrangement of the electron subsystem of aluminum upon plastic deformation at high pressures.

The mechanism of coking pressure generation I: Effect of high volatile matter coking coal, semi-anthracite and coke breeze on coking pressure and plastic coal layer permeability

Energy Technology Data Exchange (ETDEWEB)

Seiji Nomura; Merrick Mahoney; Koichi Fukuda; Kenji Kato; Anthony Le Bas; Sid McGuire [Nippon Steel Corporation, Chiba (Japan). Environment and Process Technology Center

2010-07-15

One of the most important aspects of the cokemaking process is to control and restrain the coking pressure since excessive coking pressure tends to lead to operational problems and oven wall damage. Therefore, in order to understand the mechanism of coking pressure generation, the permeability of the plastic coal layer and the coking pressure for the same single coal and the same blended coal were measured and the relationship between them was investigated. Then the 'inert' (pressure modifier) effect of organic additives such as high volatile matter coking coal, semi-anthracite and coke breeze was studied. The coking pressure peak for box charging with more uniform bulk density distribution was higher than that for top charging. It was found that the coking pressure peaks measured at different institutions (NSC and BHPBilliton) by box charging are nearly the same. The addition of high volatile matter coking coal, semi-anthracite and coke breeze to a low volatile matter, high coking pressure coal greatly increased the plastic layer permeability in laboratory experiments and correspondingly decreased the coking pressure. It was found that, high volatile matter coking coal decreases the coking pressure more than semi-anthracite at the same plastic coal layer permeability, which indicates that the coking pressure depends not only on plastic coal layer permeability but also on other factors. Coking pressure is also affected by the contraction behavior of the coke layer near the oven walls and a large contraction decreases the coal bulk density in the oven center and hence the internal gas pressure in the plastic layer. The effect of contraction on coking pressure needs to be investigated further. 33 refs., 18 figs., 5 tabs.

Primary 4πβ-γ coincidence system for standardization of radionuclides by means of plastic scintillators

International Nuclear Information System (INIS)

Baccarelli, Aida Maria

2003-01-01

The present work describes a 4π(α,β)-γ coincidence system for absolute measurement of radionuclide activity using a plastic scintillator in 4π geometry for charged particles detection and a Nal (Tl) crystal for gamma-ray detection. Several shapes and dimensions of the plastic scintillator have been tried in order to obtain the best system configuration. Radionuclides which decay by alpha emission, β - , β + and electron capture have been standardized. The results showed excellent agreement with other conventional primary system which makes use of a 4π proportional counter for X-ray and charged particle detection. The system developed in the present work have some advantages when compared with the conventional systems, namely; it does not need metal coating on the films used as radioactive source holders. When compared to liquid scintillators, is showed the advantage of not needing to be kept in dark for more than 24 h to allow phosphorescence decay of ambient light. Therefore it can be set to count immediately after the sources are placed inside of it. (author)

Quality assurance in proton beam therapy using a plastic scintillator and a commercially available digital camera.

Science.gov (United States)

Almurayshid, Mansour; Helo, Yusuf; Kacperek, Andrzej; Griffiths, Jennifer; Hebden, Jem; Gibson, Adam

2017-09-01

In this article, we evaluate a plastic scintillation detector system for quality assurance in proton therapy using a BC-408 plastic scintillator, a commercial camera, and a computer. The basic characteristics of the system were assessed in a series of proton irradiations. The reproducibility and response to changes of dose, dose-rate, and proton energy were determined. Photographs of the scintillation light distributions were acquired, and compared with Geant4 Monte Carlo simulations and with depth-dose curves measured with an ionization chamber. A quenching effect was observed at the Bragg peak of the 60 MeV proton beam where less light was produced than expected. We developed an approach using Birks equation to correct for this quenching. We simulated the linear energy transfer (LET) as a function of depth in Geant4 and found Birks constant by comparing the calculated LET and measured scintillation light distribution. We then used the derived value of Birks constant to correct the measured scintillation light distribution for quenching using Geant4. The corrected light output from the scintillator increased linearly with dose. The system is stable and offers short-term reproducibility to within 0.80%. No dose rate dependency was observed in this work. This approach offers an effective way to correct for quenching, and could provide a method for rapid, convenient, routine quality assurance for clinical proton beams. Furthermore, the system has the advantage of providing 2D visualization of individual radiation fields, with potential application for quality assurance of complex, time-varying fields. © 2017 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

Measurements of the Minimum Bending Radius of Small Diameter Scintillating Plastic Fibres

CERN Document Server

Gruber, Lukas; Vaananen, Mika Petteri; Gavardi, Laura

2018-01-01

The minimum bending radius of plastic fibres is an important parameter as it determines the geometrical flexibility of the fibres during long-term storage or installation and usage inside detectors. The following document describes measurements of the minimum bending radius of round scintillating plastic fibres with small diameter performed in the context of the LHCb SciFi Tracker project. The experimental set-up is based on measuring the light output of a bent fibre in response to 1 MeV electrons over several days. The results suggest that the 250 μm diameter fibres can be bent to a radius of about 10 mm without damaging and losing light.

Mixture quantification using PLS in plastic scintillation measurements

Energy Technology Data Exchange (ETDEWEB)

Bagan, H.; Tarancon, A.; Rauret, G. [Departament de Quimica Analitica, Universitat de Barcelona, Diagonal 647, E-08028 Barcelona (Spain); Garcia, J.F., E-mail: jfgarcia@ub.ed [Departament de Quimica Analitica, Universitat de Barcelona, Diagonal 647, E-08028 Barcelona (Spain)

2011-06-15

This article reports the capability of plastic scintillation (PS) combined with multivariate calibration (Partial least squares; PLS) to detect and quantify alpha and beta emitters in mixtures. While several attempts have been made with this purpose in mind using liquid scintillation (LS), no attempt was done using PS that has the great advantage of not producing mixed waste after the measurements are performed. Following this objective, ternary mixtures of alpha and beta emitters ({sup 241}Am, {sup 137}Cs and {sup 90}Sr/{sup 90}Y) have been quantified. Procedure optimisation has evaluated the use of the net spectra or the sample spectra, the inclusion of different spectra obtained at different values of the Pulse Shape Analysis parameter and the application of the PLS1 or PLS2 algorithms. The conclusions show that the use of PS+PLS2 applied to the sample spectra, without the use of any pulse shape discrimination, allows quantification of the activities with relative errors less than 10% in most of the cases. This procedure not only allows quantification of mixtures but also reduces measurement time (no blanks are required) and the application of this procedure does not require detectors that include the pulse shape analysis parameter.

Reactor antineutrino monitoring with a plastic scintillator array as a new safeguards method

OpenAIRE

Oguri, S.; Kuroda, Y.; Kato, Y.; Nakata, R.; Inoue, Y.; Ito, C.; Minowa, M.

2014-01-01

We developed a segmented reactor-antineutrino detector made of plastic scintillators for application as a tool in nuclear safeguards inspection and performed mostly unmanned field operations at a commercial power plant reactor. At a position outside the reactor building, we measured the difference in reactor antineutrino flux above the ground when the reactor was active and inactive.

The measurement of the fluorescence response of plastic scintillator ST1422 to neutron

International Nuclear Information System (INIS)

Luo Xiaobing; Xia Yijun; Yang Zhihua; Zhang Chuanfei; Peng Taiping; Li Rurong; Zhang Jianhua

2004-01-01

By using the T(p,n) and D(d,n) reactions as neutron resources, the fluorescence response of ST1422 plastic scintillators (40 mm in diameter and 5 mm in thickness) was determined in he neutron energy range of 0.655-5 MeV. The experimental results show a nonlinear response of fluorescence with neutron energy. (authors)

Influence of deformation rate on plasticity of metals under pressure

International Nuclear Information System (INIS)

Churbaev, R.V.; Dobromyslov, A.V.; Kolmogorov, V.L.; Taluts, G.G.

1990-01-01

Change of polycrystalline molybdenum (BCC) and titanium (HCP) plasticity under pressure depeding on the deformation rate at the room temperature is studied. It is shown that the reduction of molybdenum and titanium deformation rate leads to a substantial growth of their plastic properties with the effect being increased with pressure growth. Production of several necks testifying to the transition to a superplastic state is observed at high pressures and low deformation rates. A functional dependence of plasticity change on the deformation rate under pressure is ascertained

Plastic scintillators with high loading of one or more metal carboxylates

Science.gov (United States)

Cherepy, Nerine; Sanner, Robert Dean

2016-01-12

In one embodiment, a material includes at least one metal compound incorporated into a polymeric matrix, where the metal compound includes a metal and one or more carboxylate ligands, where at least one of the one or more carboxylate ligands includes a tertiary butyl group, and where the material is optically transparent. In another embodiment, a method includes: processing pulse traces corresponding to light pulses from a scintillator material; and outputting a result of the processing, where the scintillator material comprises at least one metal compound incorporated into a polymeric matrix, the at least one metal compound including a metal and one or more carboxylate ligands, where at least one of the one or more carboxylate ligands has a tertiary butyl group, and where the scintillator material is optically transparent and has an energy resolution at 662 keV of less than about 20%.

Pulse shape analyzer/timing-SCA application to beta measurement by plastic scintillator

International Nuclear Information System (INIS)

Celiktas, C.; Selvi, S.

2000-01-01

Noise contribution to pulses from BC-400 plastic scintillators, preamplifier and spectroscopy amplifier is rejected by using electronics processing of the modified beta spectrometer containing pulse shape analyzer/timing SCA and related complementary equipment. The noise rejection capability of the spectrometer which have been developed to measure pure and scattered beta spectra, which are reliable in view of evaluations of the detector and target electron scattering characteristics correctly. (author)

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

International Nuclear Information System (INIS)

Atac, M.

1995-11-01

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

Comparative study of large samples (2'' × 2'') plastic scintillators and EJ309 liquid with pulse shape discrimination (PSD) capabilities

International Nuclear Information System (INIS)

Iwanowska-Hanke, J; Moszynski, M; Swiderski, L; Sibczynski, P; Szczesniak, T; Krakowski, T; Schotanus, P

2014-01-01

In the paper we reported on the scintillation properties and pulse shape discrimination (PSD) performance of new plastic scintillators. The samples with dimension of 2 inches × 2 inches were tested: EJ299-34, EJ299-34G, EJ299-33 and EJ299-33G. They are the first commercially available plastics with neutron/gamma discrimination properties. The paper covers the measurements of emission spectra, photoelectron yield, analysis of the light pulse shapes originating from events related to gamma-rays and fast neutrons as well as neutron/gamma discrimination. The tested plastics are characterized by a photoelectron yield on a level of approximately 1600-2500 phe/MeV, depending on the sample. The highest value, measured for EJ299-34, is similar to the number of photoelectrons measured for EJ309 (2600 phe/MeV). The figure of merit (FOM) calculated for narrow energy cuts — indicating the PSD performance — showed that the PSD capabilities of the plastics are significantly lower than of EJ309. These scintillators are still under development in order to optimize the composition and manufacturing procedures. At this time the results obtained with the new plastics suggest their possible use as an alternative for liquid scintillators, especially if we consider their inflammability and non-toxicity

Plasticity of pressure-sensitive materials

CERN Document Server

Ochsner, Andreas

2014-01-01

Classical plasticity theory of metals is independent of the hydrostatic pressure. However, if the metal contains voids or pores or if the structure is composed of cells, this classical assumption is no more valid and the influence of the hydrostatic pressure must be incorporated in the constitutive description. Looking at the microlevel, metal plasticity is connected with the uniform planes of atoms organized with long-range order. Planes may slip past each other along their close-packed directions. The result is a permanent change of shape within the crystal and plastic deformation. The presence of dislocations increases the likelihood of planes slipping. Nowadays, the theory of pressure sensitive plasticity is successfully applied to many other important classes of materials (polymers, concrete, bones etc.) even if the phenomena on the micro-level are different to classical plasticity of metals. The theoretical background of this phenomenological approach based on observations on the macro-level is describe...

Measurement of tritium with plastic scintillator surface improvement with plasma treatment

Energy Technology Data Exchange (ETDEWEB)

Yoshihara, Y.; Furuta, E. [Ochanomizu University, Bunkyo-ku, Tokyo (Japan); Ohyama, R.I.; Yokota, S. [Tokai University, Hiratsuka-shi, Kanagawa (Japan); Kato, Y.; Yoshimura, T.; Ogiwara, K. [Hitachi Aloka Medical, Mure, Mitaka-shi, Tokyo (Japan)

2015-03-15

Tritium is usually measured by using a liquid scintillation counter. However, liquid scintillator used for measurement will become radioactive waste fluid. To solve this issue, we have developed a method of measuring tritium samples with plasma-treated plastic scintillator (PS)sheets (Plasma method). The radioactive sample is held between 2 PS sheets and the whole is enclosed in a a low-potassium glass vial. With the Plasma method of 2-min plasma treatment, we have obtained measurement efficiency of 48 ± 2 % for 2 min measurement of tritium except for tritiated water. The plasma treatment makes the PS surface rough and hydrophilic which contributes to improve the contact between tritium and PS. On the other hand, it needed almost 6 hours to obtain constant measurement efficiency. The reason was that the dry-up handling in the vial needed longer time to vaporize H{sub 2}O molecules than in the air. We tried putting silica gel beads into vials to remove H{sub 2}O molecules from PS sheet surface quickly. The silica gel beads worked well and we got constant measurement efficiency within 1-3 hours. Also, we tried using other kinds of PS treated with plasma to obtain higher measurement efficiencies of tritium samples.

Optical coupling study of plastic scintillation detectors: evaluation of different silicon products

International Nuclear Information System (INIS)

Hamada, M.M.; Madi Filho, T.; Mesquita, C.H. de

1990-01-01

Properties of different optical oils and greases in the range of 320-560 nm were studied. Several parameters as the transmitance, index of refraction, plastic scintillator fluorescence emission and its influence in the resolution and pulse height of the detection system were described. This paper shows a design to analyse the optical quality or adequacy of the silicon oils and greases in the coupling between the detector and the photocathode of the photomultiplier. (author) [pt

Plastic reactor suitable for high pressure and supercritical fluid electrochemistry

DEFF Research Database (Denmark)

Branch, Jack; Alibouri, Mehrdad; Cook, David A.

2017-01-01

The paper describes a reactor suitable for high pressure, particularly supercritical fluid, electrochemistry and electrodeposition at pressures up to 30 MPa at 115◦C. The reactor incorporates two key, new design concepts; a plastic reactor vessel and the use of o-ring sealed brittle electrodes...... by the deposition of Bi. The application of the reactor to the production of nanostructures is demonstrated by the electrodeposition of ∼80 nm diameter Te nanowires into an anodic alumina on silicon template. Key advantages of the new reactor design include reduction of the number of wetted materials, particularly...... glues used for insulating electrodes, compatability with reagents incompatible with steel, compatability with microfabricated planar multiple electrodes, small volume which brings safety advantages and reduced reagent useage, and a significant reduction in experimental time....

Reconstruction of signal in plastic scintillator of PET using Tikhonov regularization.

Science.gov (United States)

Raczynski, Lech

2015-08-01

The new concept of Time of Flight Positron Emission Tomography (TOF-PET) detection system, which allows for single bed imaging of the whole human body, is currently under development at the Jagiellonian University. The Jagiellonian-PET (J-PET) detector improves the TOF resolution due to the use of fast plastic scintillators. Since registration of the waveform of signals with duration times of few nanoseconds is not feasible, a novel front-end electronics allowing for sampling in a voltage domain at four thresholds was developed. To take fully advantage of these fast signals a novel scheme of recovery of the waveform of the signal, based on idea from the Tikhonov regularization method, is presented. From the Bayes theory the properties of regularized solution, especially its covariance matrix, may be easily derived. This step is crucial to introduce and prove the formula for calculations of the signal recovery error. The method is tested using signals registered by means of the single detection module of the J-PET detector built out from the 30 cm long plastic scintillator strip. It is shown that using the recovered waveform of the signals, instead of samples at four voltage levels alone, improves the spatial resolution of the hit position reconstruction from 1.05 cm to 0.94 cm. Moreover, the obtained result is only slightly worse than the one evaluated using the original raw-signal. The spatial resolution calculated under these conditions is equal to 0.93 cm.

Using LEDs to stimulate the recovery of radiation damage to plastic scintillators

Energy Technology Data Exchange (ETDEWEB)

Wetzel, J., E-mail: james-wetzel@uiowa.edu [The University of Iowa, Iowa City, IA (United States); Tiras, E. [The University of Iowa, Iowa City, IA (United States); Bilki, B. [The University of Iowa, Iowa City, IA (United States); Beykent University, Istanbul (Turkey); Onel, Y. [The University of Iowa, Iowa City, IA (United States); Winn, D. [Fairfield University, Fairfield, CT (United States)

2017-03-15

In this study, we consider using LEDs to stimulate the recovery of scintillators damaged from radiation in high radiation environments. We irradiated scintillating tiles of polyethylene naphthalate (PEN), Eljen brand EJ-260 (EJN), an overdoped EJ-260 (EJ2P), and a lab-produced elastomer scintillator (ES) composed of p-terphenyl (ptp) in epoxy. Two different high-dose irradiations took place, with PEN dosed to 100 kGy, and the others to 78 kGy. We found that the ‘blue’ scintillators (PEN and ES) recovered faster and maximally higher with LEDs than without. Conversely exposing the ‘green’ scintillators (EJ-260) to LED light had a nearly negligible effect on the recovery. We hypothesize that the ‘green’ scintillators require wavelengths that match their absorption and emission spectra for LED stimulated recovery.

Status of timing with plastic scintillation detectors

International Nuclear Information System (INIS)

Moszynski, M.; Bengtson, B.

1979-01-01

Timing properties of scintillators and photomultipliers as well as theoretical and experimental studies of time resolution of scintillation counters are reviewed. Predictions of the theory of the scintillation pulse generation processes are compared with the data on the light pulse shape from small samples, in which the light pulse shape depends only on the composition of the scintillator. For larger samples the influence of the light collection process and the self-absorption process on the light pulse shape are discussed. The data on rise times, fwhm's, decay times and light yield of several commercial scintillators used in timing are collected. The next part of the paper deals with the properties of photomultipliers. The sources of time uncertainties in photomultipliers as a spread of the initial velocity of photoelectrons, emission of photoelectrons under different angles and from different points at the photocathode, the time spread and the gain dispersion introduced by electron photomultiplier are reviewed. The experimental data on the time jitter, single electron response and photoelectron yield of some fast photomultipliers are collected. As the time resolution of the timing systems with scintillation counters depends also on time pick-off units, a short presentation of the timing methods is given. The discussion of timing theories is followed by a review of experimental studies of the time resolution of scintillation counters. The paper is ended by an analysis of prospects on further progress of the subnanosecond timing with scintillation counters. (Auth.)

Novel method for hit-position reconstruction using voltage signals in plastic scintillators and its application to Positron Emission Tomography

Science.gov (United States)

Raczyński, L.; Moskal, P.; Kowalski, P.; Wiślicki, W.; Bednarski, T.; Białas, P.; Czerwiński, E.; Kapłon, Ł.; Kochanowski, A.; Korcyl, G.; Kowal, J.; Kozik, T.; Krzemień, W.; Kubicz, E.; Molenda, M.; Moskal, I.; Niedźwiecki, Sz.; Pałka, M.; Pawlik-Niedźwiecka, M.; Rudy, Z.; Salabura, P.; Sharma, N. G.; Silarski, M.; Słomski, A.; Smyrski, J.; Strzelecki, A.; Wieczorek, A.; Zieliński, M.; Zoń, N.

2014-11-01

Currently inorganic scintillator detectors are used in all commercial Time of Flight Positron Emission Tomograph (TOF-PET) devices. The J-PET collaboration investigates a possibility of construction of a PET scanner from plastic scintillators which would allow for single bed imaging of the whole human body. This paper describes a novel method of hit-position reconstruction based on sampled signals and an example of an application of the method for a single module with a 30 cm long plastic strip, read out on both ends by Hamamatsu R4998 photomultipliers. The sampling scheme to generate a vector with samples of a PET event waveform with respect to four user-defined amplitudes is introduced. The experimental setup provides irradiation of a chosen position in the plastic scintillator strip with an annihilation gamma quanta of energy 511 keV. The statistical test for a multivariate normal (MVN) distribution of measured vectors at a given position is developed, and it is shown that signals sampled at four thresholds in a voltage domain are approximately normally distributed variables. With the presented method of a vector analysis made out of waveform samples acquired with four thresholds, we obtain a spatial resolution of about 1 cm and a timing resolution of about 80 ps (σ).

Novel method for hit-position reconstruction using voltage signals in plastic scintillators and its application to Positron Emission Tomography

International Nuclear Information System (INIS)

Raczyński, L.; Moskal, P.; Kowalski, P.; Wiślicki, W.; Bednarski, T.; Białas, P.; Czerwiński, E.; Kapłon, Ł.; Kochanowski, A.; Korcyl, G.; Kowal, J.; Kozik, T.; Krzemień, W.; Kubicz, E.; Molenda, M.; Moskal, I.; Niedźwiecki, Sz.; Pałka, M.; Pawlik-Niedźwiecka, M.; Rudy, Z.

2014-01-01

Currently inorganic scintillator detectors are used in all commercial Time of Flight Positron Emission Tomograph (TOF-PET) devices. The J-PET collaboration investigates a possibility of construction of a PET scanner from plastic scintillators which would allow for single bed imaging of the whole human body. This paper describes a novel method of hit-position reconstruction based on sampled signals and an example of an application of the method for a single module with a 30 cm long plastic strip, read out on both ends by Hamamatsu R4998 photomultipliers. The sampling scheme to generate a vector with samples of a PET event waveform with respect to four user-defined amplitudes is introduced. The experimental setup provides irradiation of a chosen position in the plastic scintillator strip with an annihilation gamma quanta of energy 511 keV. The statistical test for a multivariate normal (MVN) distribution of measured vectors at a given position is developed, and it is shown that signals sampled at four thresholds in a voltage domain are approximately normally distributed variables. With the presented method of a vector analysis made out of waveform samples acquired with four thresholds, we obtain a spatial resolution of about 1 cm and a timing resolution of about 80 ps (σ)

Novel method for hit-position reconstruction using voltage signals in plastic scintillators and its application to Positron Emission Tomography

Energy Technology Data Exchange (ETDEWEB)

Raczyński, L., E-mail: lech.raczynski@ncbj.gov.pl [Świerk Computing Centre, National Centre for Nuclear Research, 05-400 Otwock-Świerk (Poland); Moskal, P. [Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, 30-059 Cracow (Poland); Kowalski, P.; Wiślicki, W. [Świerk Computing Centre, National Centre for Nuclear Research, 05-400 Otwock-Świerk (Poland); Bednarski, T.; Białas, P.; Czerwiński, E. [Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, 30-059 Cracow (Poland); Kapłon, Ł. [Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, 30-059 Cracow (Poland); Institute of Metallurgy and Materials Science of Polish Academy of Sciences, Cracow (Poland); Kochanowski, A. [Faculty of Chemistry, Jagiellonian University, 30-060 Cracow (Poland); Korcyl, G.; Kowal, J.; Kozik, T.; Krzemień, W.; Kubicz, E. [Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, 30-059 Cracow (Poland); Molenda, M. [Faculty of Chemistry, Jagiellonian University, 30-060 Cracow (Poland); Moskal, I.; Niedźwiecki, Sz.; Pałka, M.; Pawlik-Niedźwiecka, M.; Rudy, Z. [Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, 30-059 Cracow (Poland); and others

2014-11-11

Currently inorganic scintillator detectors are used in all commercial Time of Flight Positron Emission Tomograph (TOF-PET) devices. The J-PET collaboration investigates a possibility of construction of a PET scanner from plastic scintillators which would allow for single bed imaging of the whole human body. This paper describes a novel method of hit-position reconstruction based on sampled signals and an example of an application of the method for a single module with a 30 cm long plastic strip, read out on both ends by Hamamatsu R4998 photomultipliers. The sampling scheme to generate a vector with samples of a PET event waveform with respect to four user-defined amplitudes is introduced. The experimental setup provides irradiation of a chosen position in the plastic scintillator strip with an annihilation gamma quanta of energy 511 keV. The statistical test for a multivariate normal (MVN) distribution of measured vectors at a given position is developed, and it is shown that signals sampled at four thresholds in a voltage domain are approximately normally distributed variables. With the presented method of a vector analysis made out of waveform samples acquired with four thresholds, we obtain a spatial resolution of about 1 cm and a timing resolution of about 80 ps (σ)

Multi element high resolution scintillator structure

International Nuclear Information System (INIS)

Cusano, D.A.

1980-01-01

A gamma camera scintillator structure, suitable for detecting high energy gamma photons which, in a single scintillator camera, would require a comparatively thick scintillator crystal, so resulting in unacceptable dispersion of light photons, comprises a collimator array of a high Z material with elongated, parallel wall channels with the scintillator material being disposed in one end of the channels so as to form an integrated collimator/scintillator structure. The collimator channel walls are preferably coated with light reflective material and further light reflective surfaces being translucent to gamma photons, may be provided in each channel. The scintillators may be single crystals or preferably comprise a phosphor dispersed in a thermosetting translucent matrix as disclosed in GB2012800A. The light detectors of the assembled camera may be photomultiplier tubes charge coupled devices or charge injection devices. (author)

Energy and angular responses of the criticality accident detector using a plastic scintillator

International Nuclear Information System (INIS)

Tsujimura, Norio; Yoshida, Tadayoshi

2006-01-01

The Japan Atomic Energy Agency (JAEA), Nuclear Fuel Cycle Engineering Laboratories, operates a spent fuel reprocessing plant and MOX (Plutonium-Uranium Mixed Oxide) fuel fabrication plants. Criticality accident detectors have been installed in these facilities. The detector, the Toshiba RD120, is composed of a plastic scintillator coupled to a photomultiplier tube, and an operational amplifier. The alarm triggering point is set to 1.0-3.6 mGy·h -1 in photon dose rate to detect the minimum accident of concern. However, a plastic scintillator is principally sensitive not only to primary photons but also to neutrons by secondary photons and heavy charged particles produced in the detector itself. The authors calculated energy and angular responses of the RD120 criticality accident detector to photons and neutrons using Monte Carlo computer codes. The response to primary photons was evaluated with the MCNP-4B and EGS4 calculations, and photon and X-ray irradiation experiments. The response to neutrons that produce secondary photons and heavy charged particles from neutron interactions was computed using the MCNP-4B and SCINFUL, respectively. As a result, reliable response functions were obtained. These results will be a great help in reassessing the coverage area and in determining the appropriate triggering dose rate level in criticality accidents. (author)

Scintillation counter with MRS APD light readout

International Nuclear Information System (INIS)

Akindinov, A.; Bondarenko, G.; Golovin, V.; Grigoriev, E.; Grishuk, Yu.; Mal'kevich, D.; Martemiyanov, A.; Ryabinin, M.; Smirnitskiy, A.; Voloshin, K.

2005-01-01

START, a high-efficiency and low-noise scintillation detector for ionizing particles, was developed for the purpose of creating a high-granular system for triggering cosmic muons. Scintillation light in START is detected by MRS APDs (Avalanche Photo-Diodes with Metal-Resistance-Semiconductor Structure), operated in the Geiger mode, which have 1mm 2 sensitive areas. START is assembled from a 15x15x1cm 3 scintillating plastic plate, two MRS APDs and two pieces of wavelength-shifting optical fiber stacked in circular coils inside the plastic. The front-end electronic card is mounted directly on the detector. Tests with START have confirmed its operational consistency, over 99% efficiency of MIP registration and good homogeneity. START demonstrates a low intrinsic noise of about 10 -2 Hz. If these detectors are to be mass-produced, the cost of a mosaic array of STARTs is estimated at a moderate level of 2-3kUSD/m 2

Design and test of a scintillation dosimeter for dosimetry measurements of high energy radiotherapy beams; Conception et realisation d'un dosimetre a scintillation adapte a la dosimetrie de faisceaux de rayonnements ionisants en faisceaux de rayonnements ionisants en radiotherapie

Energy Technology Data Exchange (ETDEWEB)

Fontbonne, J.M

2002-12-01

This work describes the design and evaluation of the performances of a scintillation dosimeter developed for the dosimetry of radiation beams used in radiotherapy. The dosimeter consists in a small plastic scintillator producing light which is guided by means of a plastic optical fiber towards photodetectors. In addition to scintillation, high energy ionizing radiations produce Cerenkov light both in the scintillator and the optical fiber. Based on a wavelength analysis, we have developed a deconvolution technique to measure the scintillation light in the presence of Cerenkov light. We stress the advantages that are anticipated from plastic scintillator, in particular concerning tissue or water equivalence (mass stopping power, mass attenuation or mass energy absorption coefficients). We show that detectors based on this material have better characteristics than conventional dosimeters such as ionisation chambers or silicon detectors. The deconvolution technique is exposed, as well as the calibration procedure using an ionisation chamber. We have studied the uncertainty of our dosimeter. The electronics noise, the fiber transmission, the deconvolution technique and the calibration errors give an overall combined experimental uncertainty of about 0,5%. The absolute response of the dosimeter is studied by means of depth dose measurements. We show that absolute uncertainty with photons or electrons beams with energies ranging from 4 MeV to 25 MeV is less than {+-} 1 %. Last, at variance with other devices, our scintillation dosimeter does not need dose correction with depth. (author)

Study of properties of the plastic scintillator EJ-260 under irradiation with 150 MeV protons and 1.2MeV gamma-rays

Science.gov (United States)

Dormenev, V.; Brinkmann, K.-T.; Korjik, M.; Novotny, R. W.

2017-11-01

One of the most critical aspects for the application of a scintillation material in high energy physics is the degradation of properties of the material in an environment of highly ionizing particles in particular due to hadrons. There are presently several detector concepts in consideration being based on organic scintillator material for fast timing of charged particles or sampling calorimeters. We have tested different samples of the organic plastic scintillator EJ-260 produced by the company Eljen Technology (Sweetwater, TX, USA). The ongoing activity has characterized the relevant parameters such as light output, kinetics and temperature dependence. The study has focused on the change of performance after irradiation with 150 MeV protons up to an integral fluence of 5·1013 protons/cm2 as well as with a strong 60Co γ-source accumulating an integral dose of 100 Gy. The paper will report on the obtained results.

Research in high energy physics: Scintillating fiber detector development for the SSC: Annual progress report

International Nuclear Information System (INIS)

Ruchti, R.C.

1988-01-01

The scintillating fiber detector development program at the University of Notre Dame is divided into several components. These include: Research on scintillating glass fiber materials; Research on scintillating plastic fiber materials; Research on scintillating liquids in fiber capillaries; Studies of improvements in image intensification and light amplification of appropriate test and development facilities at Notre Dame. The overall goal of the program is to develop efficient scintillating fiber detectors with long, optical attenuation length, and excellent radiation resistance properties for tracking and microvertex detectors and as component active sampling materials for scintillation calorimetry. We now discuss each of these programs in turn. 2 figs., 3 tabs

Memory effect, resolution, and efficiency measurements of an Al2O3 coated plastic scintillator used for radioxenon detection

Science.gov (United States)

Bläckberg, L.; Fritioff, T.; Mårtensson, L.; Nielsen, F.; Ringbom, A.; Sjöstrand, H.; Klintenberg, M.

2013-06-01

A cylindrical plastic scintillator cell, used for radioxenon monitoring within the verification regime of the Comprehensive Nuclear-Test-Ban Treaty, has been coated with 425 nm Al2O3 using low temperature Atomic Layer Deposition, and its performance has been evaluated. The motivation is to reduce the memory effect caused by radioxenon diffusing into the plastic scintillator material during measurements, resulting in an elevated detection limit. Measurements with the coated detector show both energy resolution and efficiency comparable to uncoated detectors, and a memory effect reduction of a factor of 1000. Provided that the quality of the detector is maintained for a longer period of time, Al2O3 coatings are believed to be a viable solution to the memory effect problem in question.

Memory effect, resolution, and efficiency measurements of an Al2O3 coated plastic scintillator used for radioxenon detection

International Nuclear Information System (INIS)

Bläckberg, L.; Fritioff, T.; Mårtensson, L.; Nielsen, F.; Ringbom, A.; Sjöstrand, H.; Klintenberg, M.

2013-01-01

A cylindrical plastic scintillator cell, used for radioxenon monitoring within the verification regime of the Comprehensive Nuclear-Test-Ban Treaty, has been coated with 425 nm Al 2 O 3 using low temperature Atomic Layer Deposition, and its performance has been evaluated. The motivation is to reduce the memory effect caused by radioxenon diffusing into the plastic scintillator material during measurements, resulting in an elevated detection limit. Measurements with the coated detector show both energy resolution and efficiency comparable to uncoated detectors, and a memory effect reduction of a factor of 1000. Provided that the quality of the detector is maintained for a longer period of time, Al 2 O 3 coatings are believed to be a viable solution to the memory effect problem in question

A plastic scintillator-based muon tomography system with an integrated muon spectrometer

International Nuclear Information System (INIS)

Anghel, V.; Armitage, J.; Baig, F.; Boniface, K.; Boudjemline, K.; Bueno, J.; Charles, E.; Drouin, P-L.; Erlandson, A.; Gallant, G.; Gazit, R.; Godin, D.; Golovko, V.V.; Howard, C.; Hydomako, R.

2015-01-01

A muon scattering tomography system which uses extruded plastic scintillator bars for muon tracking and a dedicated muon spectrometer that measures scattering through steel slabs has been constructed and successfully tested. The atmospheric muon detection efficiency is measured to be 97% per plane on average and the average intrinsic hit resolution is 2.5 mm. In addition to creating a variety of three-dimensional images of objects of interest, a quantitative study has been carried out to investigate the impact of including muon momentum measurements when attempting to detect high-density, high-Z material. As expected, the addition of momentum information improves the performance of the system. For a fixed data-taking time of 60 s and a fixed false positive fraction, the probability to detect a target increases when momentum information is used. This is the first demonstration of the use of muon momentum information from dedicated spectrometer measurements in muon scattering tomography

A plastic scintillator-based muon tomography system with an integrated muon spectrometer

Energy Technology Data Exchange (ETDEWEB)

Anghel, V. [Canadian Nuclear Laboratories Ltd (former Atomic Energy of Canada Ltd), Chalk River Laboratories, Chalk River, Canada K0J 1P0 (Canada); Armitage, J. [Department of Physics, Room 3302 Herzberg Laboratories, Carleton University, 1125 Colonel By Drive, Ottawa, Canada K1S 5B6 (Canada); Baig, F.; Boniface, K. [Canadian Nuclear Laboratories Ltd (former Atomic Energy of Canada Ltd), Chalk River Laboratories, Chalk River, Canada K0J 1P0 (Canada); Boudjemline, K. [Department of Physics, Room 3302 Herzberg Laboratories, Carleton University, 1125 Colonel By Drive, Ottawa, Canada K1S 5B6 (Canada); Bueno, J. [Advanced Applied Physics Solutions Inc., 4004 Wesbrook Mall, Vancouver, Canada V6T 2A3 (Canada); Charles, E. [Canada Border Services Agency, 79 Bentley Avenue, Ottawa, Canada K1A 0L8 (Canada); Drouin, P-L. [Defence Research and Development Canada, 3701 Carling Avenue, Ottawa, Canada K1A 0Z4 (Canada); Erlandson, A., E-mail: Andrew.Erlandson@cnl.ca [Department of Physics, Room 3302 Herzberg Laboratories, Carleton University, 1125 Colonel By Drive, Ottawa, Canada K1S 5B6 (Canada); Canadian Nuclear Laboratories Ltd (former Atomic Energy of Canada Ltd), Chalk River Laboratories, Chalk River, Canada K0J 1P0 (Canada); Gallant, G. [Canada Border Services Agency, 79 Bentley Avenue, Ottawa, Canada K1A 0L8 (Canada); Gazit, R. [Advanced Applied Physics Solutions Inc., 4004 Wesbrook Mall, Vancouver, Canada V6T 2A3 (Canada); Godin, D.; Golovko, V.V. [Canadian Nuclear Laboratories Ltd (former Atomic Energy of Canada Ltd), Chalk River Laboratories, Chalk River, Canada K0J 1P0 (Canada); Howard, C. [Defence Research and Development Canada, 3701 Carling Avenue, Ottawa, Canada K1A 0Z4 (Canada); Hydomako, R. [Advanced Applied Physics Solutions Inc., 4004 Wesbrook Mall, Vancouver, Canada V6T 2A3 (Canada); Defence Research and Development Canada, 3701 Carling Avenue, Ottawa, Canada K1A 0Z4 (Canada); and others

2015-10-21

A muon scattering tomography system which uses extruded plastic scintillator bars for muon tracking and a dedicated muon spectrometer that measures scattering through steel slabs has been constructed and successfully tested. The atmospheric muon detection efficiency is measured to be 97% per plane on average and the average intrinsic hit resolution is 2.5 mm. In addition to creating a variety of three-dimensional images of objects of interest, a quantitative study has been carried out to investigate the impact of including muon momentum measurements when attempting to detect high-density, high-Z material. As expected, the addition of momentum information improves the performance of the system. For a fixed data-taking time of 60 s and a fixed false positive fraction, the probability to detect a target increases when momentum information is used. This is the first demonstration of the use of muon momentum information from dedicated spectrometer measurements in muon scattering tomography.

A plastic scintillator-based muon tomography system with an integrated muon spectrometer

Science.gov (United States)

Anghel, V.; Armitage, J.; Baig, F.; Boniface, K.; Boudjemline, K.; Bueno, J.; Charles, E.; Drouin, P.-L.; Erlandson, A.; Gallant, G.; Gazit, R.; Godin, D.; Golovko, V. V.; Howard, C.; Hydomako, R.; Jewett, C.; Jonkmans, G.; Liu, Z.; Robichaud, A.; Stocki, T. J.; Thompson, M.; Waller, D.

2015-10-01

A muon scattering tomography system which uses extruded plastic scintillator bars for muon tracking and a dedicated muon spectrometer that measures scattering through steel slabs has been constructed and successfully tested. The atmospheric muon detection efficiency is measured to be 97% per plane on average and the average intrinsic hit resolution is 2.5 mm. In addition to creating a variety of three-dimensional images of objects of interest, a quantitative study has been carried out to investigate the impact of including muon momentum measurements when attempting to detect high-density, high-Z material. As expected, the addition of momentum information improves the performance of the system. For a fixed data-taking time of 60 s and a fixed false positive fraction, the probability to detect a target increases when momentum information is used. This is the first demonstration of the use of muon momentum information from dedicated spectrometer measurements in muon scattering tomography.

Time resolution of the plastic scintillator strips with matrix photomultiplier readout for J-PET tomograph

Science.gov (United States)

Moskal, P.; Rundel, O.; Alfs, D.; Bednarski, T.; Białas, P.; Czerwiński, E.; Gajos, A.; Giergiel, K.; Gorgol, M.; Jasińska, B.; Kamińska, D.; Kapłon, Ł.; Korcyl, G.; Kowalski, P.; Kozik, T.; Krzemień, W.; Kubicz, E.; Niedźwiecki, Sz; Pałka, M.; Raczyński, L.; Rudy, Z.; Sharma, N. G.; Słomski, A.; Silarski, M.; Strzelecki, A.; Wieczorek, A.; Wiślicki, W.; Witkowski, P.; Zieliński, M.; Zoń, N.

2016-03-01

Recent tests of a single module of the Jagiellonian Positron Emission Tomography system (J-PET) consisting of 30 cm long plastic scintillator strips have proven its applicability for the detection of annihilation quanta (0.511 MeV) with a coincidence resolving time (CRT) of 0.266 ns. The achieved resolution is almost by a factor of two better with respect to the current TOF-PET detectors and it can still be improved since, as it is shown in this article, the intrinsic limit of time resolution for the determination of time of the interaction of 0.511 MeV gamma quanta in plastic scintillators is much lower. As the major point of the article, a method allowing to record timestamps of several photons, at two ends of the scintillator strip, by means of matrix of silicon photomultipliers (SiPM) is introduced. As a result of simulations, conducted with the number of SiPM varying from 4 to 42, it is shown that the improvement of timing resolution saturates with the growing number of photomultipliers, and that the 2× 5 configuration at two ends allowing to read twenty timestamps, constitutes an optimal solution. The conducted simulations accounted for the emission time distribution, photon transport and absorption inside the scintillator, as well as quantum efficiency and transit time spread of photosensors, and were checked based on the experimental results. Application of the 2× 5 matrix of SiPM allows for achieving the coincidence resolving time in positron emission tomography of ≈ 0.170 ns for 15 cm axial field-of-view (AFOV) and ≈ 0.365 ns for 100 cm AFOV. The results open perspectives for construction of a cost-effective TOF-PET scanner with significantly better TOF resolution and larger AFOV with respect to the current TOF-PET modalities.

A projective geometry lead fiber scintillator detector

International Nuclear Information System (INIS)

Paar, H.; Thomas, D.; Sivertz, M.; Ong, B.; Acosta, D.; Taylor, T.; Shreiner, B.

1990-01-01

The Superconducting Super Collider (SSC), presently under construction near Dallas, Texas requires highly sophisticated particle detectors. The energy and particle flux at the SSC are more than an order of magnitude higher than the highest machine located at the Fermi National Accelerator near Chicago. An important element of particle detectors for the SSC is the calorimeter. It measures a particle's energy by sampling its energy deposit in heavy material, such as (depleted) uranium or lead. The sampling medium must be interspersed with heavy absorber material. In the case of scintillating plastic, two methods are under consideration: plates and fibers. In the case of plates, a sandwich of scintillator plates and uranium plates is constructed. In the use of fibers (still in the prototype stage), 1 mm. diameter cylindrical scintillating fibers are inserted into grooves that are machined into lead layers. The layers are stacked and epoxied together to form the required geometrical shape of the detector. Lead and scintillating plastic sampling can meet the physics requirements of the detector. This has been shown in an R ampersand D program which is underway at the University of California at San Diego (UCSD), High Energy Physics Group. This R ampersand D is funded by the Department of Energy, High Energy Physics and SSC Divisions

Advanced Multilayer Composite Heavy-Oxide Scintillator Detectors for High Efficiency Fast Neutron Detection

Science.gov (United States)

Ryzhikov, Vladimir D.; Naydenov, Sergei V.; Pochet, Thierry; Onyshchenko, Gennadiy M.; Piven, Leonid A.; Smith, Craig F.

2018-01-01

We have developed and evaluated a new approach to fast neutron and neutron-gamma detection based on large-area multilayer composite heterogeneous detection media consisting of dispersed granules of small-crystalline scintillators contained in a transparent organic (plastic) matrix. Layers of the composite material are alternated with layers of transparent plastic scintillator material serving as light guides. The resulting detection medium - designated as ZEBRA - serves as both an active neutron converter and a detection scintillator which is designed to detect both neutrons and gamma-quanta. The composite layers of the ZEBRA detector consist of small heavy-oxide scintillators in the form of granules of crystalline BGO, GSO, ZWO, PWO and other materials. We have produced and tested the ZEBRA detector of sizes 100x100x41 mm and greater, and determined that they have very high efficiency of fast neutron detection (up to 49% or greater), comparable to that which can be achieved by large sized heavy-oxide single crystals of about Ø40x80 cm3 volume. We have also studied the sensitivity variation to fast neutron detection by using different types of multilayer ZEBRA detectors of 100 cm2 surface area and 41 mm thickness (with a detector weight of about 1 kg) and found it to be comparable to the sensitivity of a 3He-detector representing a total cross-section of about 2000 cm2 (with a weight of detector, including its plastic moderator, of about 120 kg). The measured count rate in response to a fast neutron source of 252Cf at 2 m for the ZEBRA-GSO detector of size 100x100x41 mm3 was 2.84 cps/ng, and this count rate can be doubled by increasing the detector height (and area) up to 200x100 mm2. In summary, the ZEBRA detectors represent a new type of high efficiency and low cost solid-state neutron detector that can be used for stationary neutron/gamma portals. They may represent an interesting alternative to expensive, bulky gas counters based on 3He or 10B neutron

EXPERIMENTAL AND MONTE CARLO INVESTIGATIONS OF BCF-12 SMALL‑AREA PLASTIC SCINTILLATION DETECTORS FOR NEUTRON PINHOLE CAMERA.

Science.gov (United States)

Bielecki, J; Drozdowicz, K; Dworak, D; Igielski, A; Janik, W; Kulinska, A; Marciniak, L; Scholz, M; Turzanski, M; Wiacek, U; Woznicka, U; Wójcik-Gargula, A

2017-12-11

Plastic organic scintillators such as the blue-emitting BCF-12 are versatile and inexpensive tools. Recently, BCF-12 scintillators have been foreseen for investigation of the spatial distribution of neutrons emitted from dense magnetized plasma. For this purpose, small-area (5 mm × 5 mm) detectors based on BCF-12 scintillation rods and Hamamatsu photomultiplier tubes were designed and constructed at the Institute of Nuclear Physics. They will be located inside the neutron pinhole camera of the PF-24 plasma focus device. Two different geometrical layouts and approaches to the construction of the scintillation element were tested. The aim of this work was to determine the efficiency of the detectors. For this purpose, the experimental investigations using a neutron generator and a Pu-Be source were combined with Monte Carlo computations using the Geant4 code. © The Author(s) 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

X-ray imaging and detection using plastic scintillating fibers

CERN Document Server

Ikhlef, A; Beddar, A S

2000-01-01

This paper discusses the application of plastic scintillating fiber array in X-ray imaging with low-energy radiation. This array is coupled to a multichannel intensified photocathode and then to a CCD detector via a fiber optics taper. The length of the fiber array is experimentally optimized for the radiation used. We found here that the length of the fibers (interaction medium) does not contribute too much in the degradation of the spatial resolution under 10 keV irradiation along the axis of the fiber array. Modulation Transfer Function (MTF) measurements of the PSF array are compared to the optics MTF of the imaging system (without the sample) and that cross-talk in the fiber array is found to be negligible for a fiber array thickness of 20 mm.

PROTVINO: Mass-production of scintillator tiles by injection moulding

International Nuclear Information System (INIS)

Anon.

1994-01-01

The technique of the segmented sandwich-calorimeters with wavelength-shifting readout, especially its large-scale application in big detectors, requires enormous quantities of a cheap scintillator tiles of moderate dimensions (20 x 20 cm 2 ). Initial trials carried out in the Institute for High Energy Physics (IHEP), Protvino, Russia almost ten years ago showed that manufacturing such scintillator tiles was possible using an ordinary commercially-available granulated optical polystyrene, an existing technology of plastic dyeing, and a well-known process of the injection moulding, used to produce plastic goods (like buttons!)

TH-CD-BRA-12: Impact of a Magnetic Field On the Response From a Plastic Scintillation Detector

Energy Technology Data Exchange (ETDEWEB)

Therriault-Proulx, F; Wen, Z; Ibbott, G; Beddar, S [UT MD Anderson Cancer Center, Houston, TX (United States)

2016-06-15

Purpose: To study the effect of a strong magnetic field on the scintillation and the stem effect from a plastic scintillation detector (PSD) and evaluate its accuracy to measure dose. Methods: A plastic scintillation detector and a bare plastic fiber were placed inside a magnet of adjustable field strength (B=0−1.5T) and irradiated by a 6-MV photon beam (Elekta Versa HD LINAC). The PSD was built in-house using a scintillating fiber (BCF-60, 3-mm long × 1-mm diameter) coupled to an optical fiber similar to the bare fiber (PMMA, 12-m long, 1-mm diameter). Light output spectra were acquired with a spectrometer. Intensity and shape of the output spectra were compared as a function of the magnetic field strength. The bare fiber was used to study the behavior of the stem effect (composed of Cerenkov and fluorescence). The spectrometry setup allowed to perform a previously demonstrated hyperspectral stem-effect removal and calculated dose was studied as a function of the magnetic field strength. Results: Signal intensities were shown to increase with the magnetic field strength by up to 19% and 79% at 1.5T in comparison to the irradiation without a magnetic field, for respectively the PSD and the bare fiber. The light produced by Cerenkov effect in the optical fiber was shown to be the major component affected by the magnetic field. Effect of the magnetic field on the electrons trajectory may explain this behavior. Finally, accounting for the stem effect using the hyperspectral approach led to accuracy in dose measurement within 2.6%. Interestingly, variations in accuracy were negligible for values over 0.3T. Conclusion: Dependence of PSDs to magnetic field is mainly due to the Cerenkov light. When accounting for it, PSDs become a candidate of choice for both quality assurance and in vivo dosimetry of therapy under strong magnetic fields (e.g. for MRI-Linacs).

LPG based all plastic pressure sensor

DEFF Research Database (Denmark)

Bundalo, Ivan-Lazar; Lwin, R.; Leon-Saval, S.

2015-01-01

A prototype all-plastic pressure sensor is presented and characterized for potential use as an endoscope. The sensor is based on Long Period Gratings (LPG) inscribed with a CO2 laser in 6-ring microstructured PMMA fiber. Through a latex coated, plastic 3D-printed transducer pod, external pressure...... is converted to longitudinal elongation of the pod and therefore of the fiber containing the LPG. The sensor has been characterised for pressures of up to 160 mBar in an in-house built pressure chamber. Furthermore, the influence of the fiber prestrain, fiber thickness and the effect of different glues...

Surface preparation and coupling in plastic scintillator dosimetry

International Nuclear Information System (INIS)

Ayotte, Guylaine; Archambault, Louis; Gingras, Luc; Lacroix, Frederic; Beddar, A. Sam; Beaulieu, Luc

2006-01-01

One way to improve the performance of scintillation dosimeters is to increase the light-collection efficiency at the coupling interfaces of the detector system. We performed a detailed study of surface preparation of scintillating fibers and their coupling with clear optical fibers to minimize light loss and increase the amount of light collected. We analyzed fiber-surface polishing with aluminum oxide sheets, coating fibers with magnesium oxide, and the use of eight different coupling agents (air, three optical gels, an optical curing agent, ultraviolet light, cyanoacrylate glue, and acetone). We prepared 10 scintillating fiber and clear optical fiber light guide samples to test different coupling methods. To test the coupling, we first cut both the scintillating fiber and the clear optical fiber. Then, we cleaned and polished both ends of both fibers. Finally, we coupled the scintillating fiber with the clear optical fiber in either a polyethylene jacket or a V-grooved support depending on the coupling agent used. To produce more light, we used an ultraviolet lamp to stimulate scintillation. A typical series of similar couplings showed a standard deviation in light-collection efficiency of 10%. This can be explained by differences in the surface preparation quality and alignment of the scintillating fiber with the clear optical fiber. Absence of surface polishing reduced the light collection by approximately 40%, and application of magnesium oxide on the proximal end of the scintillating fiber increased the amount of light collected from the optical fiber by approximately 39%. Of the coupling agents, we obtained the best results using one of the optical gels. Because a large amount of the light produced inside a scintillator is usually lost, better light-collection efficiency will result in improved sensitivity

The measurement of temperature effect of light output of scintillators

International Nuclear Information System (INIS)

Ji Changsong; Zhou Zaiping; Zhang Longfang

1999-01-01

The author describes a experiment equipment used for measurement of temperature effect of light output of scintillators; gives some measurement results of temperature effect of light output for NaI(Tl), CsI(Tl), plastic scintillator, ZnS(Ag), anthracene crystal glass scintillator; analyzes the error factors affecting the measurement results. The total uncertainty of the temperature effect measurement for NaI(Tl) and plastic scintillator is 11%

Scintillation counter based radiation dosimeter

International Nuclear Information System (INIS)

Shin, Jeong Hyun

2009-02-01

The average human exposure per year is about 240mrem which is come from Radon and human body and terrestrial and cosmic radiation and man-made source. Specially radiation exposure through air from environmental radiation sources is 80mrem/yr(= 0.01mR/hr) which come from Terrestrial and cosmic radiation. Radiation dose is defined as energy deposit/mass. There are two major methods to detect radiation. First method is the energy integration using Air equivalent material like GM counter wall material. Second method is the spectrum to dose conversion method using NaI(Tl), HPGe. These two methods are using generally to detect radiation. But these methods are expensive. So we need new radiation detection method. The research purpose is the development of economical environmental radiation dosimeter. This system consists of Plastic/Inorganic scintillator and Si photo-diode based detector and counting based circuitry. So count rate(cps) can be convert to air exposure rate(R/hr). There are three major advantages in this system. First advantages is no high voltage power supply like GM counter. Second advantage is simple electronics. Simple electronics system can be achieved by Air-equivalent scintillation detector with Al filter for the same detection efficiency vs E curve. From former two advantages, we can know the most important advantages of the this system. Third advantage is economical system. The price of typical GM counter is about $1000. But the price of our system is below $100 because of plastic scintillator and simple electronics. The role of scintillation material is emitting scintillation which is the flash of light produced in certain materials when they absorb ionizing radiation. Plastic scintillator is organic scintillator which is kind of hydrocarbons. The special point are cheap price, large size production(∼ton), moderate light output, fast light emission(ns). And the role of Al filter is equalizing counting efficiency of air and scintillator for

Scintillation Particle Detectors Based on Plastic Optical Fibres and Microfluidics

CERN Document Server

Mapelli, Alessandro; Renaud, Philippe

2011-01-01

This thesis presents the design, development, and experimental validation of two types of scintillation particle detectors with high spatial resolution. The first one is based on the well established scintillating fibre technology. It will complement the ATLAS (A Toroidal Large ApparatuS) detector at the CERN Large Hadron Collider (LHC). The second detector consists in a microfabricated device used to demonstrate the principle of operation of a novel type of scintillation detector based on microfluidics. The first part of the thesis presents the work performed on a scintillating fibre tracking system for the ATLAS experiment. It will measure the trajectory of protons elastically scattered at very small angles to determine the absolute luminosity of the CERN LHC collider at the ATLAS interaction point. The luminosity of an accelerator characterizes its performance. It is a process-independent parameter that is completely determined by the properties of the colliding beams and it relates the cross section of a ...

Scintillating plate calorimeter optical design

International Nuclear Information System (INIS)

McNeil, R.; Fazely, A.; Gunasingha, R.; Imlay, R.; Lim, J.

1990-01-01

A major technical challenge facing the builder of a general purpose detector for the SSC is to achieve an optimum design for the calorimeter. Because of its fast response and good energy resolution, scintillating plate sampling calorimeters should be considered as a possible technology option. The work of the Scintillating Plate Calorimeter Collaboration is focused on compensating plate calorimeters. Based on experimental and simulation studies, it is expected that a sampling calorimeter with alternating layers of high-Z absorber (Pb, W, DU, etc.) and plastic scintillator can be made compensating (e/h = 1.00) by suitable choice of the ratio of absorber/scintillator thickness. Two conceptual designs have been pursued by this subsystem collaboration. One is based on lead as the absorber, with read/out of the scintillator plates via wavelength shifter fibers. The other design is based on depleted uranium as the absorber with wavelength shifter (WLS) plate readout. Progress on designs for the optical readout of a compensating scintillator plate calorimeter are presented. These designs include readout of the scintillator plates via wavelength shifter plates or fiber readout. Results from radiation damage studies of the optical components are presented

High Efficiency, Low Cost Scintillators for PET

International Nuclear Information System (INIS)

Kanai Shah

2007-01-01

Inorganic scintillation detectors coupled to PMTs are an important element of medical imaging applications such as positron emission tomography (PET). Performance as well as cost of these systems is limited by the properties of the scintillation detectors available at present. The Phase I project was aimed at demonstrating the feasibility of producing high performance scintillators using a low cost fabrication approach. Samples of these scintillators were produced and their performance was evaluated. Overall, the Phase I effort was very successful. The Phase II project will be aimed at advancing the new scintillation technology for PET. Large samples of the new scintillators will be produced and their performance will be evaluated. PET modules based on the new scintillators will also be built and characterized

49 CFR 192.191 - Design pressure of plastic fittings.

Science.gov (United States)

2010-10-01

... 49 Transportation 3 2010-10-01 2010-10-01 false Design pressure of plastic fittings. 192.191... Components § 192.191 Design pressure of plastic fittings. (a) Thermosetting fittings for plastic pipe must conform to ASTM D 2517, (incorporated by reference, see § 192.7). (b) Thermoplastic fittings for plastic...

Positron emission measurement with coincidence counting technic using large plastic scintillators

International Nuclear Information System (INIS)

Espinasse, P.; Minchella, P.

1990-01-01

For measuring positron emission of a large organ such as the brain for example, a device has been built with two cylindric plastic scintillators allowing the detection in coincidence of the 511 keV gamma rays without any spectrometry. The main results are for the sensitivity at the center of the field with 22 Na source in water: 240 ips/MBq; background = 12 ips, and for the countloss due to the deadtime >5% with 42 MBq. Sensitivity is almost uniform on the main axis between the probes. It falls to about 50% on the edges of a central diameter of 20 cm. The performances could certainly be improved by using modern rapid photomultipliers [fr

Reduction of cosmic-ray components by veto plastic scintillator

International Nuclear Information System (INIS)

Hamajima, Y.; Komura, K.

2004-01-01

The cosmic-ray component causes the background (BG) in the Ge detector set up on the above ground. The background reduction system was examined by using a plastic scintillator (PS) as a guard counter. It was possible to detect cosmic-ray enough even with a thin PS (0.5 mm in thickness). The resolving time of the timing signal between PS and Ge detector was needed for 10 microseconds. In anti-coincidence with the timing signals of PS, it was possible to reject 90% of the cosmic-ray component by setting up PS to cover the above hemisphere of the Ge detector. It is significant for the anti-coincidence system at above ground to set up effective shield by using ultra low BG Ge and shielding materials as much as possible. It was difficult to reject the secondary neutron component with this system. (author)

Scintillator plate calorimetry

International Nuclear Information System (INIS)

Price, L.E.

1990-01-01

Calorimetry using scintillator plates or tiles alternated with sheets of (usually heavy) passive absorber has been proven over multiple generations of collider detectors. Recent detectors including UA1, CDF, and ZEUS have shown good results from such calorimeters. The advantages offered by scintillator calorimetry for the SSC environment, in particular, are speed (<10 nsec), excellent energy resolution, low noise, and ease of achieving compensation and hence linearity. On the negative side of the ledger can be placed the historical sensitivity of plastic scintillators to radiation damage, the possibility of nonuniform response because of light attenuation, and the presence of cracks for light collection via wavelength shifting plastic (traditionally in sheet form). This approach to calorimetry is being investigated for SSC use by a collaboration of Ames Laboratory/Iowa State University, Argonne National Laboratory, Bicron Corporation, Florida State University, Louisiana State University, University of Mississippi, Oak Ridge National Laboratory, Virginia Polytechnic Institute and State University, Westinghouse Electric Corporation, and University of Wisconsin

Performance assessment of a 2D array of plastic scintillation detectors for IMRT quality assurance

Science.gov (United States)

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

2013-07-01

The purposes of this work are to assess the performance of a 2D plastic scintillation detectors array prototype for quality assurance in intensity-modulated radiation therapy (IMRT) and to determine its sensitivity and specificity to positioning errors of one multileaf collimator (MLC) leaf and one MLC leaf bank by applying the principles of signal detection theory. Ten treatment plans (step-and-shoot delivery) and one volumetric modulated arc therapy plan were measured and compared to calculations from two treatment-planning systems (TPSs) and to radiochromic films. The averages gamma passing rates per beam found for the step-and-shoot plans were 95.8% for the criteria (3%, 2 mm), 97.8% for the criteria (4%, 2 mm), and 98.1% for the criteria (3%, 3 mm) when measurements were compared to TPS calculations. The receiver operating characteristic curves for the one leaf errors and one leaf bank errors were determined from simulations (theoretical upper limits) and measurements. This work concludes that arrays of plastic scintillation detectors could be used for IMRT quality assurance in clinics. The use of signal detection theory could improve the quality of dosimetric verifications in radiation therapy by providing optimal discrimination criteria for the detection of different classes of errors.

Performance assessment of a 2D array of plastic scintillation detectors for IMRT quality assurance

International Nuclear Information System (INIS)

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

2013-01-01

The purposes of this work are to assess the performance of a 2D plastic scintillation detectors array prototype for quality assurance in intensity-modulated radiation therapy (IMRT) and to determine its sensitivity and specificity to positioning errors of one multileaf collimator (MLC) leaf and one MLC leaf bank by applying the principles of signal detection theory. Ten treatment plans (step-and-shoot delivery) and one volumetric modulated arc therapy plan were measured and compared to calculations from two treatment-planning systems (TPSs) and to radiochromic films. The averages gamma passing rates per beam found for the step-and-shoot plans were 95.8% for the criteria (3%, 2 mm), 97.8% for the criteria (4%, 2 mm), and 98.1% for the criteria (3%, 3 mm) when measurements were compared to TPS calculations. The receiver operating characteristic curves for the one leaf errors and one leaf bank errors were determined from simulations (theoretical upper limits) and measurements. This work concludes that arrays of plastic scintillation detectors could be used for IMRT quality assurance in clinics. The use of signal detection theory could improve the quality of dosimetric verifications in radiation therapy by providing optimal discrimination criteria for the detection of different classes of errors. (paper)

Plastic Scintillator Based Detector for Observations of Terrestrial Gamma-ray Flashes.

Science.gov (United States)

Barghi, M. R., Sr.; Delaney, N.; Forouzani, A.; Wells, E.; Parab, A.; Smith, D.; Martinez, F.; Bowers, G. S.; Sample, J.

2017-12-01

We present an overview of the concept and design of the Light and Fast TGF Recorder (LAFTR), a balloon borne gamma-ray detector designed to observe Terrestrial Gamma-Ray Flashes (TGFs). Terrestrial Gamma-Ray Flashes (TGFs) are extremely bright, sub-millisecond bursts of gamma-rays observed to originate inside thunderclouds coincident with lightning. LAFTR is joint institutional project built by undergraduates at the University of California Santa Cruz and Montana State University. It consists of a detector system fed into analog front-end electronics and digital processing. The presentation focuses specifically on the UCSC components, which consists of the detector system and analog front-end electronics. Because of the extremely high count rates observed during TGFs, speed is essential for both the detector and electronics of the instrument. The detector employs a fast plastic scintillator (BC-408) read out by a SensL Silicon Photomultiplier (SiPM). BC-408 is chosen for its speed ( 4 ns decay time) and low cost and availability. Furthermore, GEANT3 simulations confirm the scintillator is sensitive to 500 counts at 7 km horizontal distance from the TGF source (for a 13 km source altitude and 26 km balloon altitude) and to 5 counts out to 20 km. The signal from the SiPM has a long exponential decay tail and is sent to a custom shaping circuit board that amplifies and shapes the signal into a semi-Gaussian pulse with a 40 ns FWHM. The signal is then input to a 6-channel discriminator board that clamps the signal and outputs a Low Voltage Differential Signal (LVDS) for processing by the digital electronics.

Real-time volumetric scintillation dosimetry

International Nuclear Information System (INIS)

Beddar, S

2015-01-01

The goal of this brief review is to review the current status of real-time 3D scintillation dosimetry and what has been done so far in this area. The basic concept is to use a large volume of a scintillator material (liquid or solid) to measure or image the dose distributions from external radiation therapy (RT) beams in three dimensions. In this configuration, the scintillator material fulfills the dual role of being the detector and the phantom material in which the measurements are being performed. In this case, dose perturbations caused by the introduction of a detector within a phantom will not be at issue. All the detector configurations that have been conceived to date used a Charge-Coupled Device (CCD) camera to measure the light produced within the scintillator. In order to accurately measure the scintillation light, one must correct for various optical artefacts that arise as the light propagates from the scintillating centers through the optical chain to the CCD chip. Quenching, defined in its simplest form as a nonlinear response to high-linear energy transfer (LET) charged particles, is one of the disadvantages when such systems are used to measure the absorbed dose from high-LET particles such protons. However, correction methods that restore the linear dose response through the whole proton range have been proven to be effective for both liquid and plastic scintillators. Volumetric scintillation dosimetry has the potential to provide fast, high-resolution and accurate 3D imaging of RT dose distributions. Further research is warranted to optimize the necessary image reconstruction methods and optical corrections needed to achieve its full potential

New fast organic scintillators using intramolecular bromine quenching

International Nuclear Information System (INIS)

Berlman, I.B.; Lutz, S.S.; Flournoy, J.M.; Ashford, C.B.; Franks, L.A.

1984-01-01

Organic scintillator solutions with decay times as fast as 500 ps and with relatively high conversion efficiencies have been developed. The intramolecular quenching was achieved through the novel approach of adding a bromine atom to the 3- or 4-position of para-oligophenylenes, the fluorescent solutes in these binary solutions. The bromine serves to enhance singlet-to-triplet intersystem crossing in the chromophore, causing a reduction in the scintillation yield and a concomitant reduction in the decay time. The very fast value given above probably also involves some intermolecular self-quenching at high concentration. In addition, the bromine reduces the symmetry of the molecules, thereby increasing their solubility. Finally, an alkyl chain on the opposite para position further increases the solubility and also increases the immunity of the chromophore to quenching. The decay times for binary liquid solutions in toluene (at the indicated concentrations) were 0.51 ns for 4-BHTP (0.14 M), 0.75 ns for 3-BHTP (0.14 M), 0.57 ns for 3-BTP (0.14 M), and 1.3 ns for 4-BHQP (0.06 M). Binary plastics with 4-BHTP as the solute in concentrations up to 0.14 M were cast in polystyrene. The shortest decay time, 0.40 ns, was measured for the 0.14 M concentration. A plastic scintillator containing 3-BTP (0.11 M in polystyrene) had a decay time of 0.85 ns. These results compare favorably with the plastic scintillator BC-422 whose decay time is about 1.4 ns. (orig./HSI)

Radiation distribution measurement using plastic scintillating optical fibers for survey of radioactive contamination in wide area

International Nuclear Information System (INIS)

Ito, Chikara; Ito, Keisuke; Ishikawa, Takashi; Yoshida, Akihiro; Sanada, Yukihisa; Torii, Tatsuo; Nohtomi, Akihiro; Wakabayashi, Genichiro; Miyazaki, Nobuyuki

2013-01-01

It is important to examine distribution of environmental contamination due to the accident of Fukushima Daiichi Nuclear Power Station and to confirm the effect of decontamination works. We have applied radiation distribution measurement using plastic scintillating optical fibers (PSFs) in the survey of contamination in wide area including residential, farmland, forests, etc. In the measurements system, two scintillation lights that emitted at an incidence of a radiation transmit to photomultiplier tubes at the both end of PSFs. The position where scintillation light emitted is obtained from the detection time difference of each photomultiplier tube. The distribution of light emission quantity indicates the distribution of radiation incident in a PSF which is corresponds to the distribution of dose-rate. The radiation detection system using the PSFs has been applied to the radiation distribution measurement on grounds, trees, etc. The results show a good agreement with point data measured by survey meters using sodium iodide scintillators. As the PSFs which have water resistance, they have been successfully applied to the radiation distribution measurement in the river. We have also succeeded in measuring two-dimensional distribution of radiation by measuring the count rate while moving to the fiber at a constant speed. (author)

DETECTORS: scintillating fibres

International Nuclear Information System (INIS)

Anon.

1994-01-01

In the continual search for improved detection techniques, new materials are continually proving profitable. A good example is scintillating plastic fibres - tiny transparent threads sometimes finer than a human hair which transmit light. The narrowness and flexibility of these fibres was a major breakthrough for endoscopy - non-invasive techniques for viewing the otherwise inaccessible in surgery or machine inspection. In a more sophisticated form, these fibres find ready application in communications technology, where the goal is to transmit information rather than electrical power, replacing conventional and unwieldy current-carrying wire conductors. In particle physics, fibres have long been used to take the tiny scintillations produced when high energy particles hit fluorescent materials and 'conduct' them to photosensitive detectors some distance away

SU-E-T-486: In Vivo Skin Dosimetry Using the Exradin W1 Plastic Scintillation Detector for Passively Scattered Proton Beam Therapy

International Nuclear Information System (INIS)

Alsanea, F; Kudchadker, R; Usama, M; Beddar, S; Wootton, L

2015-01-01

Purpose: To evaluate the accuracy and usefulness of plastic scintillation detectors used for skin dosimetry of patients undergoing passive scatter proton therapy. Methods: Following an IRB approved protocol, six patients undergoing passively scattered proton beam therapy for prostate cancer were selected for in vivo skin dosimetry using the Exradin W1 plastic scintillator. The detector was calibrated on a Cobalt-60 unit, and phantom measurements in the proton beam with the W1 and a calibrated parallel plate ion chamber were used to account for the under-response due to high LET at energies used for treatment. Measurements made in a heated water tank were used to account for temperature dependence. For in vivo measurements, the W1 is fixed to the patient’s skin with medical tape in the center of each of two laterally opposed treatment fields. Measurements will be performed once per week for each patient for the duration of treatment, for a total of thirty six measurements. The measured dose will be compared to the expected dose, extracted from the Eclipse treatment planning system. The average difference over all measurements and per-patient will be computed, as well as standard deviations. Results: The calibrated detector exhibited a 7% under-response in 225 and 250 MeV beams, and a 4% under-response when used at 37 °C (relative to the response at the calibration temperature of 20 °C). Patient measurements are ongoing. Conclusion: The Exradin W1 plastic scintillator detector is a strong candidate for in vivo skin dosimetry in passively scattered proton beams as PSDs are water equivalent and very small (2mm in diameter), permitting accurate measurements that do not perturb the delivered dose. This project was supported in part by award number CA182450 from the National Cancer Institute

Memory effect, resolution, and efficiency measurements of an Al{sub 2}O{sub 3} coated plastic scintillator used for radioxenon detection

Energy Technology Data Exchange (ETDEWEB)

Bläckberg, L., E-mail: lisa.blackberg@physics.uu.se [Department of Physics and Astronomy, Uppsala University, Box 516, SE-75120 Uppsala (Sweden); Fritioff, T.; Mårtensson, L.; Nielsen, F.; Ringbom, A. [Division of Defence and Security Systems, Swedish Defence Research Agency (FOI), SE-17290 Stockholm (Sweden); Sjöstrand, H.; Klintenberg, M. [Department of Physics and Astronomy, Uppsala University, Box 516, SE-75120 Uppsala (Sweden)

2013-06-21

A cylindrical plastic scintillator cell, used for radioxenon monitoring within the verification regime of the Comprehensive Nuclear-Test-Ban Treaty, has been coated with 425 nm Al{sub 2}O{sub 3} using low temperature Atomic Layer Deposition, and its performance has been evaluated. The motivation is to reduce the memory effect caused by radioxenon diffusing into the plastic scintillator material during measurements, resulting in an elevated detection limit. Measurements with the coated detector show both energy resolution and efficiency comparable to uncoated detectors, and a memory effect reduction of a factor of 1000. Provided that the quality of the detector is maintained for a longer period of time, Al{sub 2}O{sub 3} coatings are believed to be a viable solution to the memory effect problem in question.

Triple pulse shape discrimination and capture-gated spectroscopy in a composite heterogeneous scintillator

Energy Technology Data Exchange (ETDEWEB)

Sharma, M., E-mail: mksharma@umich.edu [University of Michigan, Ann Arbor, MI 48109 (United States); Nattress, J. [University of Michigan, Ann Arbor, MI 48109 (United States); Wilhelm, K. [Pennsylvania State University, University Park, PA 16802 (United States); Jovanovic, I. [University of Michigan, Ann Arbor, MI 48109 (United States)

2017-06-11

We demonstrate an all-solid-state design for a composite heterogeneous scintillation detector sensitive to interactions with high-energy photons (gammas), fast neutrons, and thermal neutrons. The scintillator exhibits triple pulse shape discrimination, effectively separating electron recoils, fast neutron recoils, and neutron captures. This is accomplished by combining the properties of two distinct scintillators, whereby a 51-mm diameter, 51-mm tall cylinder of pulse shape discriminating plastic is wrapped by a 320-µm thick sheet of {sup 6}LiF:ZnS(Ag), optically coupling the scintillators to each other and to the photomultiplier tube. In this way, the sensitivity to neutron captures is achieved without the need to load the plastic scintillator with a capture agent. We demonstrate a figure of merit of up to 1.2 for fast neutrons/gammas and 5.7 for thermal neutrons/gammas. Intrinsic capture efficiency is found to be 0.46±0.05% and is in good agreement with simulation, while gamma rejection was 10{sup −6} with respect to the capture region and 10{sup −4} with respect to the recoil region using a 300 keVee threshold. Finally, we show an improvement in capture-gated neutron spectroscopy by rejecting accidental gamma coincidences using pulse shape discrimination in the plastic scintillator.

A systematic characterization of the low-energy photon response of plastic scintillation detectors

Science.gov (United States)

Boivin, Jonathan; Beddar, Sam; Bonde, Chris; Schmidt, Daniel; Culberson, Wesley; Guillemette, Maxime; Beaulieu, Luc

2016-08-01

To characterize the low energy behavior of scintillating materials used in plastic scintillation detectors (PSDs), 3 PSDs were developed using polystyrene-based scintillating materials emitting in different wavelengths. These detectors were exposed to National Institute of Standards and Technology (NIST)-matched low-energy beams ranging from 20 kVp to 250 kVp, and to 137Cs and 60Co beams. The dose in polystyrene was compared to the dose in air measured by NIST-calibrated ionization chambers at the same location. Analysis of every beam quality spectrum was used to extract the beam parameters and the effective mass energy-absorption coefficient. Monte Carlo simulations were also performed to calculate the energy absorbed in the scintillators’ volume. The scintillators’ expected response was then compared to the experimental measurements and an energy-dependent correction factor was identified to account for low-energy quenching in the scintillators. The empirical Birks model was then compared to these values to verify its validity for low-energy electrons. The clear optical fiber response was below 0.2% of the scintillator’s light for x-ray beams, indicating that a negligible amount of fluorescence contamination was produced. However, for higher-energy beams (137Cs and 60Co), the scintillators’ response was corrected for the Cerenkov stem effect. The scintillators’ response increased by a factor of approximately 4 from a 20 kVp to a 60Co beam. The decrease in sensitivity from ionization quenching reached a local minimum of about 11%+/- 1% between 40 keV and 60 keV x-ray beam mean energy, but dropped by 20% for very low-energy (13 keV) beams. The Birks model may be used to fit the experimental data, but it must take into account the energy dependence of the kB quenching parameter. A detailed comprehension of intrinsic scintillator response is essential for proper calibration of PSD dosimeters for radiology.

High efficiency scintillation detectors

International Nuclear Information System (INIS)

Noakes, J.E.

1976-01-01

A scintillation counter consisting of a scintillation detector, usually a crystal scintillator optically coupled to a photomultiplier tube which converts photons to electrical pulses is described. The photomultiplier pulses are measured to provide information on impinging radiation. In inorganic crystal scintillation detectors to achieve maximum density, optical transparency and uniform activation, it has been necessary heretofore to prepare the scintillator as a single crystal. Crystal pieces fail to give a single composite response. Means are provided herein for obtaining such a response with crystal pieces, such means comprising the combination of crystal pieces and liquid or solid organic scintillator matrices having a cyclic molecular structure favorable to fluorescence. 8 claims, 6 drawing figures

Neutron Detection with Large Plastic Scintillators for RPM Applications

International Nuclear Information System (INIS)

Corre, G.; Boudergui, K.; Sannie, G.; Kondrasovs, V.

2015-01-01

Homeland security requests the use Radiation Portal Monitor (RPM). They must be able to detect and differentiate gamma and neutron radiation. Gamma detection is required for illicit transportation of radioactive matter detection. Neutron detection is important to control nonproliferation of enriched material. Manufacturers worldwide propose sensors based on 3 He which give the actual state of art in term of neutron detection. The imminent shortage of 3 He forces manufacturers to find viable alternative. From 10 years sensors providers have the challenge to replace previous 3 He detectors that are known to be the most commonly deployed neutron sensor. As 3 He detectors can only detect neutron, they must be completed with gamma detector. The proposed approach is based on pulse time correlation between adjacent sensors from signal collected by EJ200 plastic scintillators. Results obtained during FP7 Scintilla project test campaigns show the system relevance for replacement of today's 3 He detectors. (authors)

Selective Beta and Gamma-ray Discrimination by CdWO{sub 4} and PlasticScintillator

Energy Technology Data Exchange (ETDEWEB)

Bae, Jun Woo; Kim, Hee Reyoung [Dept. of Nuclear Engineering, Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

2017-04-15

Radiation monitoring technique has been used for monitoring of decommissioning site of nuclear facility, radioactive waste disposal site, or in case of radioactivity accident. For rapid measurement of gamma-ray and beta-ray, many portable radiation detectors were developed but they are sensitive to specific radiation type. For example, portable detectors using NaI(Tl) or high purity germanium (HPGe) are suitable to detect gamma-ray. Otherwise, Geiger-müller (GM) tube or ionization chamber are suitable to detect all-types of radiation but it is hard to determine which particle is detected in the detector. In this reason, phoswich detectors for discrimination of beta-ray and gamma-ray were developed by using pulse shape discrimination. In this study, another approach to discriminate the beta-ray and gamma-ray is carried out. Two scintillators are used, cadmium tungstate (CdWO{sub 4}) and plastic scintillator. They have huge difference in their effective atomic number and mass density, thus they have huge difference in their gamma-ray sensitivity while the sensitivity of beta-ray is similar. The characterization of beta-ray and gamma-ray discrimination by using this characteristics is include. A technique of discrimination between beta-ray and gamma-ray was suggested. The method was verified by Monte Carlo simulation and experiment. This work showed feasibility on in field measurement of radiation with discrimination of beta-ray and gamma-ray.

High pressure phase transformations revisited

Science.gov (United States)

Levitas, Valery I.

2018-04-01

High pressure phase transformations play an important role in the search for new materials and material synthesis, as well as in geophysics. However, they are poorly characterized, and phase transformation pressure and pressure hysteresis vary drastically in experiments of different researchers, with different pressure transmitting media, and with different material suppliers. Here we review the current state, challenges in studying phase transformations under high pressure, and the possible ways in overcoming the challenges. This field is critically compared with fields of phase transformations under normal pressure in steels and shape memory alloys, as well as plastic deformation of materials. The main reason for the above mentioned discrepancy is the lack of understanding that there is a fundamental difference between pressure-induced transformations under hydrostatic conditions, stress-induced transformations under nonhydrostatic conditions below yield, and strain-induced transformations during plastic flow. Each of these types of transformations has different mechanisms and requires a completely different thermodynamic and kinetic description and experimental characterization. In comparison with other fields the following challenges are indicated for high pressure phase transformation: (a) initial and evolving microstructure is not included in characterization of transformations; (b) continuum theory is poorly developed; (c) heterogeneous stress and strain fields in experiments are not determined, which leads to confusing material transformational properties with a system behavior. Some ways to advance the field of high pressure phase transformations are suggested. The key points are: (a) to take into account plastic deformations and microstructure evolution during transformations; (b) to formulate phase transformation criteria and kinetic equations in terms of stress and plastic strain tensors (instead of pressure alone); (c) to develop multiscale continuum

High pressure phase transformations revisited.

Science.gov (United States)

Levitas, Valery I

2018-04-25

High pressure phase transformations play an important role in the search for new materials and material synthesis, as well as in geophysics. However, they are poorly characterized, and phase transformation pressure and pressure hysteresis vary drastically in experiments of different researchers, with different pressure transmitting media, and with different material suppliers. Here we review the current state, challenges in studying phase transformations under high pressure, and the possible ways in overcoming the challenges. This field is critically compared with fields of phase transformations under normal pressure in steels and shape memory alloys, as well as plastic deformation of materials. The main reason for the above mentioned discrepancy is the lack of understanding that there is a fundamental difference between pressure-induced transformations under hydrostatic conditions, stress-induced transformations under nonhydrostatic conditions below yield, and strain-induced transformations during plastic flow. Each of these types of transformations has different mechanisms and requires a completely different thermodynamic and kinetic description and experimental characterization. In comparison with other fields the following challenges are indicated for high pressure phase transformation: (a) initial and evolving microstructure is not included in characterization of transformations; (b) continuum theory is poorly developed; (c) heterogeneous stress and strain fields in experiments are not determined, which leads to confusing material transformational properties with a system behavior. Some ways to advance the field of high pressure phase transformations are suggested. The key points are: (a) to take into account plastic deformations and microstructure evolution during transformations; (b) to formulate phase transformation criteria and kinetic equations in terms of stress and plastic strain tensors (instead of pressure alone); (c) to develop multiscale continuum

Solid scintillator 'Ready Cap' for measurement with a liquid scintillation counter

International Nuclear Information System (INIS)

Ijiri, Kenichi; Endo, Masashi; Nogawa, Norio; Tsuda, Shoko; Nakamura, Aiko; Morikawa, Naotake; Osaki, Susumu.

1990-01-01

'Ready Cap', a small plastic container coated with solid scintillator has recently been introduced (Beckman Instruments, Inc.). Pulse height spectra and counting efficiencies obtained with a liquid scintillator and Ready Cap using a liquid scintillation counter were compared for 15 different radionuclides. For radionuclides emitting low-energy β-rays or characteristic X-rays, the spectra for Ready Cap shifted toward the higher energy side compared with the spectra for the liquid scintillator. This tendency was reversed for the nuclides emitting higher-energy β-radiations ( 36 Cl and 32 P). Generally, counting efficiencies both in Ready Cap and in liquid scintillator increased with increase in the energy of β- or X-rays. For some nuclides, Ready Cap gave higher counting efficiencies and for others it gave lower values than in the liquid scintillator. However, the differences were not large within each nuclide. The use of Ready Cap is recommended for measurements of radionuclides when liquid scintillation cocktails have no means of waste disposal under the present Japanese radioisotope regulation. (author)

Use of pliable bags in liquid scintillation counting

International Nuclear Information System (INIS)

Simonnet, G.; Jacquet, M.A.; Sharif, A.; Engler, R.

1981-01-01

Pliable plastic bags have been used to replace glass or plastic vials for liquid scintillation counting. The two major advantages of this method are the lower cost of the plastic bags and the fact that, per sample, the radioactive waste is significantly reduced. The following parameters have been checked: the impermeability of the bags to various scintillator mixtures and the fact that neither the irregular shape of the bags nor their position in the counting chamber had any effect on the results of the counting. The latter was also constant with time, at least over a period of 10 days. The technique has been used to count the radioactivity of 3 H-DNA precipitates prepared from bacteria and lymphocytes and deposited on filters impregnated with only 200 μl scintillator. It is a method that can be applied to the counting of any samples deposited on filters and insoluble in scintillator. (author)

Water Vapor Permeation in Plastics

Energy Technology Data Exchange (ETDEWEB)

Keller, Paul E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kouzes, Richard T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2017-01-01

Polyvinyl toluene (PVT) and polystyrene (PS) (referred to as “plastic scintillator”) are used for gamma ray detectors. A significant decrease in radiation detection performance has been observed in some PVT-based gamma-ray detectors in systems in outdoor environments as they age. Recent studies have revealed that plastic scintillator can undergo an environmentally related material degradation that adversely affects gamma ray detection performance under certain conditions and histories. A significant decrease in sensitivity has been seen in some gamma-ray detectors in some systems as they age. The degradation of sensitivity of plastic scintillator over time is due to a variety of factors, and the term “aging” is used to encompass all factors. Some plastic scintillator samples show no aging effects (no significant change in sensitivity over more than 10 years), while others show severe aging (significant change in sensitivity in less than 5 years). Aging effects arise from weather (variations in heat and humidity), chemical exposure, mechanical stress, light exposure, and loss of volatile components. The damage produced by these various causes can be cumulative, causing observable damage to increase over time. Damage may be reversible up to some point, but becomes permanent under some conditions. The objective of this report is to document the phenomenon of permeability of plastic scintillator to water vapor and to derive the relationship between time, temperature, humidity and degree of water penetration in plastic. Several conclusions are documented about the properties of water permeability of plastic scintillator.

Study of a 4πβ-γ coincidence system for absolute radionuclide activity measurement using plastic scintillators

International Nuclear Information System (INIS)

Piuvezam Filho, Helio

2007-01-01

The present work was intended to study a coincidence system 4π(PS)β-γ for absolute activity measurement using plastic scintillators in 4π geometry. Along with experiments on the coincidence system, simulations were also performed applying the Monte Carlo Method, by means of codes PENELOPE and ESQUEMA. These simulations were performed in order to calculate the extrapolation curve of the coincidence system 4π(PS)β-γ and compare it to experimental data. A new geometry was proposed to the coincidence system adding up a second photomultiplier tube to the previous system for improving light collection from the plastic scintillator, as this system presented limitations in the minimum detected energy due to the presence of electronic noise and low gain. The results show that an improvement in the signal-to-noise ratio was obtained, as well as in the minimum detected energy. Moreover, there was an increase in the detection efficiency. With these modifications, it is now possible to calibrate radionuclides which emit low energy electrons or X-rays, increasing the number of radionuclides that can be standardized with this type of system.(author)

The impact law of confining pressure and plastic parameter on Dilatancy of rock

Science.gov (United States)

Wang, Bin; Zhang, Zhenjie; Zhu, Jiebing

2017-08-01

Based on cyclic loading-unloading triaxle test of marble, the double parameter dilation angle model is established considering confining pressure effect and plastic parameter. Research shows that not only the strength but also the militancy behavior is highly depended on its confining pressure and plastic parameter during process of failure. Dilation angle evolution law shows obvious nonlinear characteristic almost with a rapid increase to the peak and then decrease gradually with plastic increasing, and the peak dilation angle value is inversely proportional with confining pressure. The proposed double parameter nonlinear dilation angle model can be used to well describe the Dilatancy of rock, which helps to understand the failure mechanism of surrounding rock mass and predict the range of plastic zone.

A large neutron missing mass spectrometer using long plastic scintillators with electronical determination of the neutron interaction point

International Nuclear Information System (INIS)

Apel, W.D.; Mueller, H.; Schinzel, D.; Sigurdsson, G.; Staudenmaier, H.M.; Stier, U.

1975-11-01

A large acceptance and high efficiency neutron detector is described. The sensitive area and volume of the detector is 3.07 m 2 and 1.03 m 3 respectively. The detector consists of sixteen elements of plastic scintillator, each having the dimensions (16 x 16 x 240) cm 3 . The mean detection efficiency is about 33% for neutrons of 100-500 MeV/c momentum. An interesting feature of this instrument is the accuracy achieved in locating incident particles, which is +-3 cm for charged particles and +-4 cm for neutrons. The accuracy achieved for the time-of-flight measurement is +-1 nsec for fast neutrons. (orig.) [de

Spectral characterization of plastic scintillation detector response as a function of magnetic field strength

Science.gov (United States)

Simiele, E.; Kapsch, R.-P.; Ankerhold, U.; Culberson, W.; DeWerd, L.

2018-04-01

The purpose of this work was to characterize intensity and spectral response changes in a plastic scintillation detector (PSD) as a function of magnetic field strength. Spectra measurements as a function of magnetic field strength were performed using an optical spectrometer. The response of both a PSD and PMMA fiber were investigated to isolate the changes in response from the scintillator and the noise signal as a function of magnetic field strength. All irradiations were performed in water at a photon beam energy of 6 MV. Magnetic field strengths of (0, ±0.35, ±0.70, ±1.05, and  ±1.40) T were investigated. Four noise subtraction techniques were investigated to evaluate the impact on the resulting noise-subtracted scintillator response with magnetic field strength. The noise subtraction methods included direct spectral subtraction, the spectral method, and variants thereof. The PMMA fiber exhibited changes in response of up to 50% with magnetic field strength due to the directional light emission from \\breve{C} erenkov radiation. The PSD showed increases in response of up to 10% when not corrected for the noise signal, which agrees with previous investigations of scintillator response in magnetic fields. Decreases in the \\breve{C} erenkov light ratio with negative field strength were observed with a maximum change at  ‑1.40 T of 3.2% compared to 0 T. The change in the noise-subtracted PSD response as a function of magnetic field strength varied with the noise subtraction technique used. Even after noise subtraction, the PSD exhibited changes in response of up to 5.5% over the four noise subtraction methods investigated.

Semiconductor high-energy radiation scintillation detector

International Nuclear Information System (INIS)

Kastalsky, A.; Luryi, S.; Spivak, B.

2006-01-01

We propose a new scintillation-type detector in which high-energy radiation generates electron-hole pairs in a direct-gap semiconductor material that subsequently recombine producing infrared light to be registered by a photo-detector. The key issue is how to make the semiconductor essentially transparent to its own infrared light, so that photons generated deep inside the semiconductor could reach its surface without tangible attenuation. We discuss two ways to accomplish this, one based on doping the semiconductor with shallow impurities of one polarity type, preferably donors, the other by heterostructure bandgap engineering. The proposed semiconductor scintillator combines the best properties of currently existing radiation detectors and can be used for both simple radiation monitoring, like a Geiger counter, and for high-resolution spectrography of the high-energy radiation. An important advantage of the proposed detector is its fast response time, about 1 ns, essentially limited only by the recombination time of minority carriers. Notably, the fast response comes without any degradation in brightness. When the scintillator is implemented in a qualified semiconductor material (such as InP or GaAs), the photo-detector and associated circuits can be epitaxially integrated on the scintillator slab and the structure can be stacked-up to achieve virtually any desired absorption capability

Investigation of the failure of a reactor pressure vessel by plastic instability

International Nuclear Information System (INIS)

Laemmer, H.; Ritter, B.

1994-01-01

A possible consequence of a core meltdown accident in a pressurized water reactor is the failure of the reactor pressure vessel under high internal pressure. With the aid of the finite element program ABAQUS and using a material model of the thermo-plasticity for large deformation, the failure of the reactor pressure vessel due to plastic instability was examined. It was apparent from the finite element calculations that solely due to reduction in strength of the material, even for internal wall temperatures clearly below the core melt; of about 2000 C, the critical internal pressure can fall to values which are lower than the working pressure. With the aid of simplified geometry, a lower limit for the pressure at failure of the reactor pressure vessel can be calculated. (orig./HP) [de

Measurements of energy resolution with hemispheric scintillators

International Nuclear Information System (INIS)

Mendonca, A.C.S.; Binns, D.A.C.; Tauhata, L.; Poledna, R.

1980-01-01

The hemispheric configuration is used for plastic scintillators type NE 102 with the aiming to optimize the light collect. Scintillators at this configuration, with radii of 3,81 cm and 2,54 cm, are showing improvement about 16-17% in the energy resolution, on cilyndric scintillators with the same volume, for gamma rays of 511-1275 KeV. (E.G.) [pt

Plastic Gamma Sensors: An Application in Detection of Radioisotopes

International Nuclear Information System (INIS)

Mukhopadhyay, S.

2003-01-01

A brief survey of plastic scintillators for various radiation measurement applications is presented here. The utility of plastic scintillators for practical applications such as gamma radiation monitoring, real-time radioisotope detection and screening is evaluated in laboratory and field measurements. This study also reports results of Monte Carlo-type predictive responses of common plastic scintillators in gamma and neutron radiation fields. Small-size plastic detectors are evaluated for static and dynamic gamma-ray detection sensitivity of selected radiation sources

Prototype tests for a highly granular scintillator-based hadronic calorimeter

OpenAIRE

Liu, Yong; Collaboration, for the CALICE

2017-01-01

Within the CALICE collaboration, several concepts for the hadronic calorimeter of a future lepton collider detector are studied. After having demonstrated the capabilities of the measurement methods in "physics prototypes", the focus now lies on improving their implementation in "technological prototypes", that are scalable to the full linear collider detector. The Analogue Hadronic Calorimeter (AHCAL) concept is a sampling calorimeter of tungsten or steel absorber plates and plastic scintill...

Readout of plastic scintillators with cooled large-area avalanche photodiodes

Energy Technology Data Exchange (ETDEWEB)

Mykulyak, A.; Kapusta, M.; Lynen, U.; Moszynski, M.; Mueller, W.F.J.; Orth, H.; Schwarz, C.; Szawlowski, M.; Trautmann, W.; Trzcinski, A.; Wolski, D.; Zwieglinski, B. E-mail: bzw@fuw.edu.pl

2004-05-11

Time-of-flight measurements in multifragmentation of heavy, relativistic projectiles require very good time resolution and at the same time the detecting system must cope with a dynamic range of up to 8000:1. We look into the possibility of application of large-area avalanche photodiodes (LAAPDs) as alternative light sensors to meet the above requirements. The paper presents the results of our amplitude and time response studies of a plastic scintillator BC-408 readout with a phi16 mm LAAPD using radioactive sources. The measurements were performed using two different setups. The best time resolution has been obtained by exploiting LAAPD cooling to increase its gain beyond that accessible at room temperature. We reach 610 ps (FWHM) at -26 deg. C for the corresponding LAAPD gain of {approx}900 and the {sup 90}Sr/{sup 90}Y {beta}-ray source. We hope to reach below the desired 400 ps with the latter setup at the higher light levels available with multifragmentation products.

Effects of Temperature and X-rays on Plastic Scintillating Fiber and Infrared Optical Fiber.

Science.gov (United States)

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

2015-05-11

In this study, we have studied the effects of temperature and X-ray energy variations on the light output signals from two different fiber-optic sensors, a fiber-optic dosimeter (FOD) based on a BCF-12 as a plastic scintillating fiber (PSF) and a fiber-optic thermometer (FOT) using a silver halide optical fiber as an infrared optical fiber (IR fiber). During X-ray beam irradiation, the scintillating light and IR signals were measured simultaneously using a dosimeter probe of the FOD and a thermometer probe of the FOT. The probes were placed in a beaker with water on the center of a hotplate, under variation of the tube potential of a digital radiography system or the temperature of the water in the beaker. From the experimental results, in the case of the PSF, the scintillator light output at the given tube potential decreased as the temperature increased in the temperature range from 25 to 60 °C. We demonstrated that commonly used BCF-12 has a significant temperature dependence of -0.263 ± 0.028%/°C in the clinical temperature range. Next, in the case of the IR fiber, the intensity of the IR signal was almost uniform at each temperature regardless of the tube potential range from 50 to 150 kVp. Therefore, we also demonstrated that the X-ray beam with an energy range used in diagnostic radiology does not affect the IR signals transmitted via a silver halide optical fiber.

PALS investigations of free volumes thermal expansion of J-PET plastic scintillator synthesized in polystyrene matrix

Directory of Open Access Journals (Sweden)

Wieczorek Anna

2015-12-01

Full Text Available The polystyrene doped with 2,5-diphenyloxazole as a primary fluor and 2-(4-styrylphenylbenzoxazole as a wavelength shifter prepared as a plastic scintillator was investigated using positronium probe in wide range of temperatures from 123 to 423 K. Three structural transitions at 260, 283, and 370 K were found in the material. In the o-Ps intensity dependence on temperature, the significant hysteresis is observed. Heated to 370 K, the material exhibits the o-Ps intensity variations in time.

Characterization of the exradin W1 plastic scintillation detector for small field applications in proton therapy

Science.gov (United States)

Hoehr, C.; Lindsay, C.; Beaudry, J.; Penner, C.; Strgar, V.; Lee, R.; Duzenli, C.

2018-05-01

Accurate dosimetry in small field proton therapy is challenging, particularly for applications such as ocular therapy, and suitable detectors for this purpose are sought. The Exradin W1 plastic scintillating fibre detector is known to out-perform most other detectors for determining relative dose factors for small megavoltage photon beams used in radiotherapy but its potential in small proton beams has been relatively unexplored in the literature. The 1 mm diameter cylindrical geometry and near water equivalence of the W1 makes it an attractive alternative to other detectors. This study examines the dosimetric performance of the W1 in a 74 MeV proton therapy beam with particular focus on detector response characteristics relevant to relative dose measurement in small fields suitable for ocular therapy. Quenching of the scintillation signal is characterized and demonstrated not to impede relative dose measurements at a fixed depth. The background cable-only (Čerenkov and radio-fluorescence) signal is 4 orders of magnitude less than the scintillation signal, greatly simplifying relative dose measurements. Comparison with other detectors and Monte Carlo simulations indicate that the W1 is useful for measuring relative dose factors for field sizes down to 5 mm diameter and shallow spread out Bragg peaks down to 6 mm in depth.

High-resolution x-ray imaging using a structured scintillator

Energy Technology Data Exchange (ETDEWEB)

Hormozan, Yashar, E-mail: hormozan@kth.se; Sychugov, Ilya; Linnros, Jan [Materials and Nano Physics, School of Information and Communication Technology, KTH Royal Institute of Technology, Electrum 229, Kista, Stockholm SE-16440 (Sweden)

2016-02-15

Purpose: In this study, the authors introduce a new generation of finely structured scintillators with a very high spatial resolution (a few micrometers) compared to conventional scintillators, yet maintaining a thick absorbing layer for improved detectivity. Methods: Their concept is based on a 2D array of high aspect ratio pores which are fabricated by ICP etching, with spacings (pitches) of a few micrometers, on silicon and oxidation of the pore walls. The pores were subsequently filled by melting of powdered CsI(Tl), as the scintillating agent. In order to couple the secondary emitted photons of the back of the scintillator array to a CCD device, having a larger pixel size than the pore pitch, an open optical microscope with adjustable magnification was designed and implemented. By imaging a sharp edge, the authors were able to calculate the modulation transfer function (MTF) of this finely structured scintillator. Results: The x-ray images of individually resolved pores suggest that they have been almost uniformly filled, and the MTF measurements show the feasibility of a few microns spatial resolution imaging, as set by the scintillator pore size. Compared to existing techniques utilizing CsI needles as a structured scintillator, their results imply an almost sevenfold improvement in resolution. Finally, high resolution images, taken by their detector, are presented. Conclusions: The presented work successfully shows the functionality of their detector concept for high resolution imaging and further fabrication developments are most likely to result in higher quantum efficiencies.

Vapor pressure measured with inflatable plastic bag

Science.gov (United States)

1965-01-01

Deflated plastic bag in a vacuum chamber measures initial low vapor pressures of materials. The bag captures the test sample vapors and visual observation of the vapor-inflated bag under increasing external pressures yields pertinent data.

A new plastic scintillation resin for single-step separation, concentration and measurement of technetium-99

Energy Technology Data Exchange (ETDEWEB)

Barrera, J. [Department of Analytical Chemistry, Universitat de Barcelona, Martí i Franqués, 1-11, E-08028, Barcelona (Spain); Tarancón, A., E-mail: alex.tarancon@ub.edu [Department of Analytical Chemistry, Universitat de Barcelona, Martí i Franqués, 1-11, E-08028, Barcelona (Spain); Bagán, H. [Department of Pure and Applied Biochemistry, Lund University, Getingevägen 60, hus II, 22100 SE, Lund (Sweden); García, J.F. [Department of Analytical Chemistry, Universitat de Barcelona, Martí i Franqués, 1-11, E-08028, Barcelona (Spain)

2016-09-14

Technetium is a synthetic element with no stable isotopes, produced as waste in nuclear power plants and in cyclotrons used for nuclear medicine. The element has high mobility, in the form of TcO{sub 4}{sup −}; its determination is therefore important for environmental protection. Technetium is found in low concentrations and therefore common methods for its analysis include long treatments in several steps and require large amounts of reagents for its purification and preconcentration. Plastic scintillation resins (PSresin) are novel materials used to separate, preconcentrate and measure radionuclides in a single step. The objective of this study is to prepare and characterise a PSresin for the preconcentration and measurement of {sup 99}Tc. The study first evaluates the reproducibility of the production of PSresins between batches and over time; showing good reproducibility and storage stability. Next, we studied the effect of some common non-radioactive interferences, showing small influences on measurement, and radioactive interferences ({sup 36}Cl and {sup 238}U/{sup 234}U). {sup 36}Cl can be removed by a simple treatment with 0.5 M HCl and {sup 238}U/{sup 234}U can be removed from the column by cleaning with a mixture of 0.1 M HNO{sub 3} and 0.1 M HF. In the latter case, a slight change in the morphology of the PSresin caused an increase in detection efficiency. Finally, the PSresin was applied to the measurement of real spiked samples (sea water and urine) with deviations lower than 10% in all cases. - Highlights: • A plastic scintillation resin for selective analysis of {sup 99}Tc has been developed. • The method is valid for analysis of {sup 99}Tc in seawater and urine samples. • Presence of Cl{sup −}, NO{sub 3}{sup −}, SO{sub 4}{sup 2−}, {sup 36}Cl, U and Th not affect retention of {sup 99}Tc.

A new plastic scintillation resin for single-step separation, concentration and measurement of technetium-99

International Nuclear Information System (INIS)

Barrera, J.; Tarancón, A.; Bagán, H.; García, J.F.

2016-01-01

Technetium is a synthetic element with no stable isotopes, produced as waste in nuclear power plants and in cyclotrons used for nuclear medicine. The element has high mobility, in the form of TcO_4"−; its determination is therefore important for environmental protection. Technetium is found in low concentrations and therefore common methods for its analysis include long treatments in several steps and require large amounts of reagents for its purification and preconcentration. Plastic scintillation resins (PSresin) are novel materials used to separate, preconcentrate and measure radionuclides in a single step. The objective of this study is to prepare and characterise a PSresin for the preconcentration and measurement of "9"9Tc. The study first evaluates the reproducibility of the production of PSresins between batches and over time; showing good reproducibility and storage stability. Next, we studied the effect of some common non-radioactive interferences, showing small influences on measurement, and radioactive interferences ("3"6Cl and "2"3"8U/"2"3"4U). "3"6Cl can be removed by a simple treatment with 0.5 M HCl and "2"3"8U/"2"3"4U can be removed from the column by cleaning with a mixture of 0.1 M HNO_3 and 0.1 M HF. In the latter case, a slight change in the morphology of the PSresin caused an increase in detection efficiency. Finally, the PSresin was applied to the measurement of real spiked samples (sea water and urine) with deviations lower than 10% in all cases. - Highlights: • A plastic scintillation resin for selective analysis of "9"9Tc has been developed. • The method is valid for analysis of "9"9Tc in seawater and urine samples. • Presence of Cl"−, NO_3"−, SO_4"2"−, "3"6Cl, U and Th not affect retention of "9"9Tc.

Test of tissue-equivalent scintillation detector for dose measurement of megavoltage beams

International Nuclear Information System (INIS)

Geso, M.; Ackerly, T.; Clift, M.A.

2000-01-01

Full text: The measurement of depth doses and profiles for a stereotactic radiotherapy beam presents special problems associated with the small beam size compared to the dosimeter's active detection area. In this work a locally fabricated organic plastic scintillator detector has been used to measure the depth dose and profile of a stereotactic radiotherapy beam. The 6MV beam is 1.25 cm diameter at isocentre, typical of small field stereotactic radiosurgery. The detector is a water/tissue equivalent plastic scintillator that is accompanied by Cerenkov subtraction detector. In this particular application, a negligible amount of Cerenkov light was detected. A photodiode and an electronic circuit is used instead of a photomultiplier for signal amplification. Comparison with data using a diode detector and a small size ionization chamber, indicate that the organic plastic scintillator detector is a valid detector for stereotactic radiosurgery dosimetry. The tissue equivalence of the organic scintillator also holds the promise of accurate dosimetry in the build up region. Depth doses measured using our plastic scintillator agree to within about 1% with those obtained using commercially available silicon diodes. Beam profiles obtained using plastic scintillator presents correct field width to within 0.35 mm, however some artifacts are visible in the profiles. These artifacts are about 5% discrepancy which has been shown not to be a significant factor in stereotactic radiotherapy dosimetry. Copyright (2000) Australasian College of Physical Scientists and Engineers in Medicine

Performance comparison of scintillators for alpha particle detectors

Energy Technology Data Exchange (ETDEWEB)

Morishita, Yuki [Graduate School of Medicine, Nagoya University, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya, Aichi 461-8673 (Japan); Japan Atomic Energy Agency, Muramatsu 4-33, Tokai-mura, Ibaraki 319-1194 (Japan); Yamamoto, Seiichi [Graduate School of Medicine, Nagoya University, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya, Aichi 461-8673 (Japan); Izaki, Kenji [Japan Atomic Energy Agency, Muramatsu 4-33, Tokai-mura, Ibaraki 319-1194 (Japan); Kaneko, Junichi H.; Toui, Kohei; Tsubota, Youichi; Higuchi, Mikio [Graduate School of Engineering, Hokkaido University, Kita 13, Nishi 8, Kita-ku, Sapporo, Hokkaido 060-8628 (Japan)

2014-11-11

Scintillation detectors for alpha particles are often used in nuclear fuel facilities. Alpha particle detectors have also become important in the research field of radionuclide therapy using alpha emitters. ZnS(Ag) is the most often used scintillator for alpha particle detectors because its light output is high. However, the energy resolution of ZnS(Ag)-based scintillation detectors is poor because they are not transparent. A new ceramic sample, namely the cerium doped Gd{sub 2}Si{sub 2}O{sub 7} (GPS) scintillator, has been tested as alpha particle detector and its performances have been compared to that one of three different scintillating materials: ZnS(Ag), GAGG and a standard plastic scintillator. The different scintillating materials have been coupled to two different photodetectors, namely a photomultiplier tube (PMT) and a Silicon Photo-multiplier (Si-PM): the performances of each detection system have been compared. Promising results as far as the energy resolution performances (10% with PMT and 14% with Si-PM) have been obtained in the case of GPS and GAGG samples. Considering the quantum efficiencies of the photodetectors under test and their relation to the emission wavelength of the different scintillators, the best results were achieved coupling the GPS with the PMT and the GAGG with the Si-PM.

Optimizing concentration of shifter additive for plastic scintillators of different size

Science.gov (United States)

Adadurov, A. F.; Zhmurin, P. N.; Lebedev, V. N.; Titskaya, V. D.

2009-02-01

This paper concerns the influence of wavelength shifting (secondary) luminescent additive (LA 2) on the light yield of polystyrene-based plastic scintillator (PS) taking self-absorption into account. Calculations of light yield dependence on concentration of 1.4-bis(2-(5-phenyloxazolyl)-benzene (POPOP) as LA 2 were made for various path lengths of photons in PS. It is shown that there is an optimal POPOP concentration ( Copt), which provides a maximum light yield for a given path length. This optimal concentration is determined by the competition of luminescence and self-reflection processes. Copt values were calculated for PS of different dimensions. For small PS, Copt≈0.02%, which agree with a common (standard) value of POPOP concentration. For higher PS dimensions, the optimal POPOP concentration is decreased (to Copt≈0.006% for 320×30×2 cm sample), reducing the light yield from PS by almost 35%.

Properties of the ukrainian polystyrene-based plastic scintillator UPS 923A

International Nuclear Information System (INIS)

Artikov, A.; Budagov, Yu.; Chirikov-Zorin, I.; Lyablin, M.; Chokheli, D.; Bellettini, G.; Mensione, A.; Tokar, S; Giokaris, N.; Manousakis-Katsikakis, A.

2005-01-01

The polystyrene-based scintillator UPS 923A was chosen for upgrading of the muon system for the CDF detector at the Fermilab Tevatron. Properties of this scintillator such as light output, light attenuation, long-term stability and also timing characteristics of the scintillator and wavelength shifting fibers were investigated. The method for the Bulk Attenuation Length measurements of the scintillator to its own light emitted was proposed. Comparative measurements of the characteristics of the UPS 923A and the polyvinyltoluene-based scintillator NE 114 were performed. It was found that natural aging of the NE 114 was two times faster than that of the UPS 923A

Polysiloxane scintillator composition

Science.gov (United States)

Walker, J.K.

1992-05-05

A plastic scintillator useful for detecting ionizing radiation comprising a matrix which comprises an optically transparent polysiloxane having incorporated therein at least one ionizing radiation-hard fluor capable of converting electromagnetic energy produced in the polysiloxane upon absorption of ionizing radiation to detectable light.

Scintillation properties of polycrystalline LaxY1-xO3 ceramic

Science.gov (United States)

Sahi, Sunil; Chen, Wei; Kenarangui, Rasool

2015-03-01

Scintillators are the material that absorbs the high-energy photons and emits visible photons. Scintillators are commonly used in radiation detector for security, medical imaging, industrial applications and high energy physics research. Two main types of scintillators are inorganic single crystals and organic (plastic or liquid) scintillators. Inorganic single crystals are expensive and difficult to grow in desire shape and size. Also, some efficient inorganic scintillator such as NaI and CsI are not environmental friendly. But on the other hand, organic scintillators have low density and hence poor energy resolution which limits their use in gamma spectroscopy. Polycrystalline ceramic can be a cost effective alternative to expensive inorganic single crystal scintillators. Here we have fabricated La0.2Y1.8O3 ceramic scintillator and studied their luminescence and scintillation properties. Ceramic scintillators were fabricated by vacuum sintering of La0.2Y1.8O3 nanoparticles at temperature below the melting point. La0.2Y1.8O3 ceramic were characterized structurally using XRD and TEM. Photoluminescence and radioluminescence studies were done using UV and X-ray as an excitation source. We have used gamma isotopes with different energy to studies the scintillation properties of La0.2Y1.8O3 scintillator. Preliminary studies of La0.2Y1.8O3 scintillator shows promising result with energy resolution comparable to that of NaI and CsI.

High efficiency algorithm for 3D transient thermo-elasto-plastic contact problem in reactor pressure vessel sealing system

International Nuclear Information System (INIS)

Xu Mingyu; Lin Tengjiao; Li Runfang; Du Xuesong; Li Shuian; Yang Yu

2005-01-01

There are some complex operating cases such as high temperature and high pressure during the operating process of nuclear reactor pressure vessel. It is necessary to carry out mechanical analysis and experimental investigation for its sealing ability. On the basis of the self-developed program for 3-D transient sealing analysis for nuclear reactor pressure vessel, some specific measures are presented to enhance the calculation efficiency in several aspects such as the non-linear solution of elasto-plastic problem, the mixed solution algorithm for contact problem as well as contract heat transfer problem and linear equation set solver. The 3-D transient sealing analysis program is amended and complemented, with which the sealing analysis result of the pressure vessel model can be obtained. The calculation results have good regularity and the calculation efficiency is twice more than before. (authors)

Dose verification of radiotherapy for lung cancer by using plastic scintillator dosimetry and a heterogeneous phantom

DEFF Research Database (Denmark)

Ottosson, Wiviann; Behrens, C. F.; Andersen, Claus E.

2015-01-01

Bone, air passages, cavities, and lung are elements present in patients, but challenging to properly correct for in treatment planning dose calculations. Plastic scintillator detectors (PSDs) have proven to be well suited for dosimetry in non-reference conditions such as small fields. The objective...... of this study was to investigate the performance of a commercial treatment planning system (TPS) using a PSD and a specially designed thorax phantom with lung tumor inserts. 10 treatment plans of different complexity and phantom configurations were evaluated. Although the TPS agreed well with the measurements...

Calibration of the time response functions of a quenched plastic scintillator for neutron time of flight

CERN Document Server

Chen, J B; Peng, H S; Tang, C H; Zhang, B H; Ding, Y K; Chen, M; Chen, H S; Li, C G; Wen, T S; Yu, R Z

2002-01-01

The time response functions of an ultrafast quenched plastic scintillation detector used to measure neutron time of flight spectra were calibrated by utilizing cosmic rays and implosion neutrons from DT-filled capsules at the Shenguang II laser facility. These sources could be regarded as delta function pulses due to their much narrower time widths than those of the time response functions of the detection system. The results showed that the detector responses to DT neutrons and to cosmic rays were 1.18 and 0.96 ns FWHM, respectively.

Development and radiation evaluation of mobile station for personnel monitoring system based on indigenous plastic scintillator sensor rods

International Nuclear Information System (INIS)

Chaudhary, H.S.; Parihar, A.; Senwar, K.R.; Prakash, V.; Rathore, A.S.

2018-01-01

The Mobile Station for Personnel Monitoring (MSPM) system has been designed and developed for rapid screening of personnel with respect to radiation contamination during nuclear or radiological emergency; it can also be used for prevention of illicit movement of radioactive sources. The objective was to develop a modular, transportable and easily deployable gamma portal monitoring system based on indigenous DLJ developed plastic scintillator sensors. The Gamma radiation response of the system is presented here

Set of counts by scintillations for atmospheric samplings; Ensemble de comptages par scintillations pour prelevements atmospheriques

Energy Technology Data Exchange (ETDEWEB)

Appriou, D.; Doury, A.

1962-07-01

The author reports the development of a scintillation-based counting assembly with the following characteristics: a photo-multiplier with a wide photo-cathode, a thin plastic scintillator for the counting of beta + alpha (and possibility of mounting an alpha scintillator), a relatively small own motion with respect to activities to be counted, a weakly varying efficiency. The authors discuss the counting objective, present equipment tests (counter, proportional amplifier and pre-amplifier, input drawer). They describe the apparatus operation, discuss the selection of scintillators, report the study of the own movement (electron-based background noise, total background noise, background noise reduction), discuss counts (influence of the external source, sensitivity to alpha radiations, counting homogeneity, minimum detectable activity) and efficiencies.

Investigation of linear accelerator pulse delivery using fast organic scintillator measurements

DEFF Research Database (Denmark)

Beierholm, Anders Ravnsborg; Andersen, Claus Erik; Lindvold, Lars René

2010-01-01

Fiber-coupled organic plastic scintillators present an attractive method for time-resolved dose measurements during radiotherapy. Most organic scintillators exhibit a fast response, making it possible to use them to measure individual high-energy X-ray pulses from a medical linear accelerator...... performed on Varian medical linear accelerators, delivering 6 MV X-ray beams. The dose delivery per radiation pulse was found to agree with expectations within roughly 1%, although minor discrepancies and transients were evident in the measurements....

SU-F-BRE-07: Experimental Validation of a Lung SBRT Technique Using a Novel, True Volumetric Plenoptic-Plastic-Scintillator Detector

International Nuclear Information System (INIS)

Goulet, M; Rilling, M; Gingras, L; Beaulieu, L; Archambault, L; Beddar, S

2014-01-01

Purpose: Lung SBRT is being used by an increasing number of clinics, including our center which recently treated its first patient. In order to validate this technique, the 3D dose distribution of the SBRT plan was measured using a previously developed 3D detector based on plenoptic camera and plastic scintillator technology. The excellent agreement between the detector measurement and the expected dose from the treatment planning system Pinnacle 3 shows great promise and amply justify the development of the technique. Methods: The SBRT treatment comprised 8 non-coplanar 6MV photon fields with a mean field size of 12 cm 2 at isocentre and a total prescription dose of 12Gy per fraction for a total of 48Gy. The 3D detector was composed of a 10×10×10 cm 2 EJ-260 water-equivalent plastic scintillator embedded inside a truncated cylindrical acrylic phantom of 10cm radius. The scintillation light was recorded using a static R5 light-field camera and the 3D dose was reconstructed at a 2mm resolution in all 3 dimensions using an iterative backprojection algorithm. Results: The whole 3D dose distribution was recorded at a rate of one acquisition per second. The mean absolute dose difference between the detector and Pinnacle 3 was 1.3% over the region with more than 10% of the maximum dose. 3D gamma tests performed over the same region yield passing rates of 98.8% and 96.6% with criteria of 3%/1mm and 2%/1mm, respectively. Conclusion: Experimental results showed that our beam modeling and treatment planning system calculation was adequate for the safe administration of small field/high dose techniques such as SBRT. Moreover, because of the real-time capability of the detector, further validation of small field rotational, dynamic or gated technique can be monitored or verified by this system

SU-F-BRE-07: Experimental Validation of a Lung SBRT Technique Using a Novel, True Volumetric Plenoptic-Plastic-Scintillator Detector

Energy Technology Data Exchange (ETDEWEB)

Goulet, M; Rilling, M; Gingras, L; Beaulieu, L; Archambault, L [CHU de Quebec and Universite Laval, Quebec, QC (Canada); Beddar, S [MD Anderson Cancer Ctr., Houston, TX (United States)

2014-06-15

Purpose: Lung SBRT is being used by an increasing number of clinics, including our center which recently treated its first patient. In order to validate this technique, the 3D dose distribution of the SBRT plan was measured using a previously developed 3D detector based on plenoptic camera and plastic scintillator technology. The excellent agreement between the detector measurement and the expected dose from the treatment planning system Pinnacle{sup 3} shows great promise and amply justify the development of the technique. Methods: The SBRT treatment comprised 8 non-coplanar 6MV photon fields with a mean field size of 12 cm{sup 2} at isocentre and a total prescription dose of 12Gy per fraction for a total of 48Gy. The 3D detector was composed of a 10×10×10 cm{sup 2} EJ-260 water-equivalent plastic scintillator embedded inside a truncated cylindrical acrylic phantom of 10cm radius. The scintillation light was recorded using a static R5 light-field camera and the 3D dose was reconstructed at a 2mm resolution in all 3 dimensions using an iterative backprojection algorithm. Results: The whole 3D dose distribution was recorded at a rate of one acquisition per second. The mean absolute dose difference between the detector and Pinnacle{sup 3} was 1.3% over the region with more than 10% of the maximum dose. 3D gamma tests performed over the same region yield passing rates of 98.8% and 96.6% with criteria of 3%/1mm and 2%/1mm, respectively. Conclusion: Experimental results showed that our beam modeling and treatment planning system calculation was adequate for the safe administration of small field/high dose techniques such as SBRT. Moreover, because of the real-time capability of the detector, further validation of small field rotational, dynamic or gated technique can be monitored or verified by this system.

Some adsorption characteristics of polysterene base scintillators

International Nuclear Information System (INIS)

Seredenko, T.N.; Ehkkerman, V.M.; Solomonov, V.M.; Gen, N.S.

1980-01-01

It is necessary to account for the adsorption on the surface of a scintillator when measuring nuclide activity in solutions by submerging into these solutions plastic scintillators. Dependences of 144 Ce, 90 Y, 137 Cs adsorption on specific activities (α) and pH value of solution were investigated. It is shown that K-α ratio is described by the equation K=Casup(p), where K is the specific surface activity of the polystyrene scintillator. Values of C and p are presented for investigated nuclides. The criterion estimating the possibility for repeated usage of scintillator are considered

Optimizing concentration of shifter additive for plastic scintillators of different size

Energy Technology Data Exchange (ETDEWEB)

Adadurov, A.F. [Institute for Scintillating materials, NPC Institute for Single Crystals, NAN of Ukraine, Lenin Avenue 61, 61001 Kharkov (Ukraine)], E-mail: adadurov@isma.kharkov.ua; Zhmurin, P.N.; Lebedev, V.N.; Titskaya, V.D. [Institute for Scintillating materials, NPC Institute for Single Crystals, NAN of Ukraine, Lenin Avenue 61, 61001 Kharkov (Ukraine)

2009-02-11

This paper concerns the influence of wavelength shifting (secondary) luminescent additive (LA{sub 2}) on the light yield of polystyrene-based plastic scintillator (PS) taking self-absorption into account. Calculations of light yield dependence on concentration of 1.4-bis(2-(5-phenyloxazolyl)-benzene (POPOP) as LA{sub 2} were made for various path lengths of photons in PS. It is shown that there is an optimal POPOP concentration (C{sub opt}), which provides a maximum light yield for a given path length. This optimal concentration is determined by the competition of luminescence and self-reflection processes. C{sub opt} values were calculated for PS of different dimensions. For small PS, C{sub opt}{approx}0.02%, which agree with a common (standard) value of POPOP concentration. For higher PS dimensions, the optimal POPOP concentration is decreased (to C{sub opt}{approx}0.006% for 320x30x2 cm sample), reducing the light yield from PS by almost 35%.

ATLAS ALFA—measuring absolute luminosity with scintillating fibres

CERN Document Server

Franz, S

2009-01-01

ALFA is a high-precision scintillating fibre tracking detector under construction for the absolute determination of the LHC luminosity at the ATLAS interaction point. This detector, mounted in so-called Roman Pots, will track protons elastically scattered under μrad angles at IP1.In total there are four pairs of vertically arranged detector modules which approach the LHC beam axis to mm distance. Each detector module consists of ten layers of two times 64 scintillating fibres each (U and V planes). The fibres are coupled to 64 channels Multi-Anodes PhotoMultipliers Tubes read out by compact front-end electronics. Each detector module is complemented by so-called overlap detectors: Three layers of two times 30 scintillating fibres which will be used to measure the relative positioning of two vertically arranged main detectors. The total number of channels is about 15000. Conventional plastic scintillator tiles are mounted in front of the fibre detectors and will serve as trigger counter. The extremely restric...

Multisector scintillation detector with fiber-optic light collection

Science.gov (United States)

Ampilogov, N. V.; Denisov, S. P.; Kokoulin, R. P.; Petrukhin, A. A.; Prokopenko, N. N.; Shulzhenko, I. A.; Unatlokov, I. B.; Yashin, I. I.

2017-07-01

A new type of scintillation detector for the use in high energy physics is described. The octagonal detector consists of eight triangular scintillator sectors with total area of 1 m2. Each sector represents two plates of 2 cm thick plastic scintillator. Seven 1 mm thick WLS fibers are laid evenly between the plates. The space between the fibers is filled with silicone compound to provide better light collection. Fiber ends from all eight sectors are gathered in the central part of the detector into a bunch and docked to the cathode of a FEU-115m photomultiplier. The read-out of the counter signals is carried out from 7th and 12th dynodes, providing a wide dynamic range up to about 10000 particles. The front-end electronics of the detector is based on the flash-ADC with a sampling frequency of 200 MHz. The features of detecting and recording systems of the multisector scintillation detector (MSD) and the results of its testing are discussed.

Design, instrumentation and response characteristics of a 2 pi multi-detector of CsI(Tl) scintillators mounted inside the Plastic Ball spectrometer

NARCIS (Netherlands)

Joulaeizadeh, L.; Gasparic, I.; Bacelar, J.; Caplar, R.; Löhner, H.

2010-01-01

A 2 pi hemispherical detector consisting of 64 CsI(Tl) scintillator modules covering the angular range of 80 degrees -160 degrees has been constructed. This detector is employed as the Inner Shell of the Plastic Ball detector and was used in two experimental programs concerning the study of pionic

Determination of the light response of BC-404 plastic scintillator for protons and deuterons with energies between 1 and 11 MeV

Energy Technology Data Exchange (ETDEWEB)

Saraf, S.K.; Brient, C.E.; Egun, P.M.; Grimes, S.M.; Mishra, V.; Pedroni, R.S.

1988-05-10

The response of BC-404 plastic scintillator is measured up to 11 MeV for protons and up to 8 MeV for deuterons using a time-of-flight spectrometer. It is shown that the response is nonlinear in this energy range and can be described very well using a four-term polynomial in energy. Earlier response curves which were extrapolated from high energy data and from interpolation of low energy data at widely separated energies are nearly linear in the low energy region. A comparison has been made between our new measured data and the existing curves.

SU-F-T-09: In Phantom Full-Implant Validation of Plastic Scintillation Detectors for in Vivo Dosimetry During Low Dose Rate Brachytherapy

Energy Technology Data Exchange (ETDEWEB)

Therriault-Proulx, F; Bruno, T; Beddar, S [UT MD Anderson Cancer Center, Houston, TX (United States); Beaulieu, L [CHU de Quebec, Quebec, QC, CA (Canada)

2016-06-15

Purpose: To validate in a water phantom the use of plastic scintillation detectors to measure dose to the urethra and the rectal wall during a clinically realistic low dose rate (LDR) brachytherapy implant. Methods: A template was designed to replicate a clinically realistic LDR brachytherapy prostate implant inside a water phantom. Twenty-two catheters were inserted, including one mimicking the urethra and another the rectal wall. The needles inserted in the remaining 20 catheters were composed of thin-walled nylon tubes in which I-125 radioactive seeds (Air Kerma Strengths of (0.328±0.020)U) were abutted together with plastic spacers to replicate a typical loading. A plastic scintillation detector (PSD) with a 5-mm long × 1-mm diameter sensitive element was first placed inside the urethra and 1-second measurements were performed for 60s after each needle implant. Measurements were also performed at multiple positions along the urethra once all the needles were inserted. The procedure was then repeated with the PSD placed at the rectal wall. Results: Individual dose-rates ranging from 0.07µGy/s to 1.5µGy/s were measured after each needle implant. The average absolute relative differences were (6.2±3.6)% and (6.9±6.5)% to the values calculated with the TG-43 formalism, for the urethra and rectal wall respectively. These results are within expectations from the error uncertainty budget once accounting for uncertainties in seeds’ strength and positioning. Interestingly, the PSD allowed for unplanned error detection as the study was performed. Finally, the measured dose after the full implant at different positions along the mimicked organs at risk were in agreement with TG-43 values for all of the positions tested. Conclusion: Plastic scintillation detectors could be used as in vivo detectors for LDR brachytherapy as they would provide accurate dose information after each needle implant as well as along the organs at risk at the end of the implant.

Applications of liquid scintillation tubes

International Nuclear Information System (INIS)

Broga, D.W.

1977-01-01

A new cocktail containing device for liquid scintillation counting, the scintillation tube, consists of a two-layered plastic bag which is heatsealed after the cocktail and sample have been placed in it. It is then placed in a carrying vial and counted in a conventional liquid scintillation counter. These tubes have proved to be a practical and economical alternative to vials. Some of their advantages are elimination of absorption problems, transparency, lower background and higher counting efficiency, low breakage danger and savings in waste disposal costs. Two applications for which the tubes are particularly suitable are the counting of laboratory swipes and urine analysis. (author)

Quasi-periodic fluctuations of atmospheric pressure and cosmic rays observed in the stratosphere

International Nuclear Information System (INIS)

Kodama, Masahiro; Abe, Toshiaki; Sakai, Takasuke; Kato, Masato; Kogami, Shinichi.

1976-01-01

Quasi-periodicities of barometric pressure and cosmic ray intensity, with 5.5-minute period and one hour persistency, have been observed by means of a high-precision barometer and a large plastic scintillation counter in a balloon at an altitude of --18 km over the Pacific Ocean. From characteristics of such short period fluctuations, it is suggested that the observed pressure fluctuation may possibly be caused by the internal atmospheric gravity wave whose amplitude and wave length are --30 m and --30 km respectively. (auth.)

Construction and beam-tests of silicon-tungsten and scintillator-SiPM modules for the CMS High Granularity Calorimeter for HL-LHC

CERN Document Server

Chang, Yung-wei

2018-01-01

A High Granularity Calorimeter (HGCAL) is being designed to replace the existing endcap calorimeters in CMS for the HL-LHC era. It features unprecedented transverse and longitudinal segmentation for both electromagnetic (ECAL) and hadronic (HCAL) compartments, with silicon sensors being chosen for the high-pseudorapidity regions due to their radiation tolerance. The remainder of the HGCAL, in the lower radiation environment, will use plastic scintillator with on-tile SiPM readout. Prototype hexagonal silicon modules, featuring a new Skiroc2-CMS front-end chip, together with a modified version of the scintillator-SiPM CALICE AHCAL, have been built and tested in beams at CERN in 2017. In this poster, we present measurements of noise, calibration, shower shapes and performance with electrons, pions and muons.

DETEC, a Subprogram for Simulation of the Fast-Neutron Detection Process in a Hydro-Carbonous Plastic Scintillator

Energy Technology Data Exchange (ETDEWEB)

Gustafsson, B; Aspelund, O

1966-07-15

A description is given of the subprogram DETEC, which for energies below 5 MeV simulates the detection process of a fast-neutron within a large cylindrical plastic scintillator. DETEC has been coded in FORTRAN IV, and consists of a subroutine and a BLOCK-DATA subprogram. The latter is in its present form adapted to the dimensions 5 cm diam. x 8 cm of the scintillating materials NE102 and NE102A. The character of DETEC as a subprogram is manifest through the requirement of a main routine for generation of the following input parameters: 1. fast-neutron position; 2. direction; 3. energy; 4. entrance time; 5. input weight (all referred to the detector surface), and 6. the discriminator threshold. When these are provided, the virtues of DETEC are recording of the detected weight and the time elapsed prior to the detection event. The merits of DETEC are finally demonstrated in two typical applications.

DETEC, a Subprogram for Simulation of the Fast-Neutron Detection Process in a Hydro-Carbonous Plastic Scintillator

International Nuclear Information System (INIS)

Gustafsson, B.; Aspelund, O.

1966-07-01

A description is given of the subprogram DETEC, which for energies below 5 MeV simulates the detection process of a fast-neutron within a large cylindrical plastic scintillator. DETEC has been coded in FORTRAN IV, and consists of a subroutine and a BLOCK-DATA subprogram. The latter is in its present form adapted to the dimensions 5 cm diam. x 8 cm of the scintillating materials NE102 and NE102A. The character of DETEC as a subprogram is manifest through the requirement of a main routine for generation of the following input parameters: 1. fast-neutron position; 2. direction; 3. energy; 4. entrance time; 5. input weight (all referred to the detector surface), and 6. the discriminator threshold. When these are provided, the virtues of DETEC are recording of the detected weight and the time elapsed prior to the detection event. The merits of DETEC are finally demonstrated in two typical applications

Toward the Probabilistic Forecasting of High-latitude GPS Phase Scintillation

Science.gov (United States)

Prikryl, P.; Jayachandran, P.T.; Mushini, S. C.; Richardson, I. G.

2012-01-01

The phase scintillation index was obtained from L1 GPS data collected with the Canadian High Arctic Ionospheric Network (CHAIN) during years of extended solar minimum 2008-2010. Phase scintillation occurs predominantly on the dayside in the cusp and in the nightside auroral oval. We set forth a probabilistic forecast method of phase scintillation in the cusp based on the arrival time of either solar wind corotating interaction regions (CIRs) or interplanetary coronal mass ejections (ICMEs). CIRs on the leading edge of high-speed streams (HSS) from coronal holes are known to cause recurrent geomagnetic and ionospheric disturbances that can be forecast one or several solar rotations in advance. Superposed epoch analysis of phase scintillation occurrence showed a sharp increase in scintillation occurrence just after the arrival of high-speed solar wind and a peak associated with weak to moderate CMEs during the solar minimum. Cumulative probability distribution functions for the phase scintillation occurrence in the cusp are obtained from statistical data for days before and after CIR and ICME arrivals. The probability curves are also specified for low and high (below and above median) values of various solar wind plasma parameters. The initial results are used to demonstrate a forecasting technique on two example periods of CIRs and ICMEs.

All-plastic fiber-based pressure sensor

DEFF Research Database (Denmark)

Bundalo, Ivan-Lazar; Lwin, Richard; Leon-Saval, Sergio

2016-01-01

We present a feasibility study and a prototype of an all-plastic fiber-based pressure sensor. The sensor is based on long period gratings inscribed for the first time to the best of our knowledge by a CO2 laser in polymethyl methacrylate (PMMA) microstructured fibers and coupled to a pod......-like transducer that converts pressure to strain. The sensor prototype was characterized for pressures up to 150 mbars, and various parameters related to its construction were also characterized in order to enhance sensitivity. We consider this sensor in the context of future applications in endoscopic pressure...... sensors....

Study on determination of 90Sr by liquid scintillation spectrometry

International Nuclear Information System (INIS)

Zhai Xiufang; Li Weiping; Tian Mei; Zou Ronghu

2012-01-01

Both of Liquid scintillation counting and Cerenkov counting can be used to determinate 90 Sr in samples by Liquid scintillation spectrometry. In this work, effects of scintillation vials wit-h different material, Liquid scintillation cocktails, sample volume, Strontium carrier, pH, quenching (chemical quenching and color quenching)are studied, and both counting methods are compared. For Liquid scintillation counting. The results show that the best appropriate volume ratio of sample and liquid scintillation cocktail is 8:12 for OPTIPHASE HISAFE-3 and OPTIPHASE HISAFE-2, stability of solution decreased when sample load exceeds the maximum load for both Liquid scintillation cocktails, and OPTIPHASE HISAFE-3 also show superior performance for high saline solution. The type of scintillation vial haven't clear influence on the MDA of 90 Sr. Chemical quenching and color quenching can decrease the counting efficiency. For Cerenkov counting, the lowest MDA is obtained when polyethylene plastic vial is used and sample volume is 20 ml. Color quenching decreases the counting efficiency, while there isn't chemical quenching for Cerenkov counting. The MDA of 90 Sr is 1.19 and 1.00 Bq/L for Liquid scintillation counting and Cerenkov counting with the optimal labeling condition. (authors)

49 CFR 192.619 - Maximum allowable operating pressure: Steel or plastic pipelines.

Science.gov (United States)

2010-10-01

... plastic pipelines. 192.619 Section 192.619 Transportation Other Regulations Relating to Transportation... Operations § 192.619 Maximum allowable operating pressure: Steel or plastic pipelines. (a) No person may operate a segment of steel or plastic pipeline at a pressure that exceeds a maximum allowable operating...

High-symmetry organic scintillator systems

Science.gov (United States)

Feng, Patrick L.

2017-07-18

An ionizing radiation detector or scintillator system includes a scintillating material comprising an organic crystalline compound selected to generate photons in response to the passage of ionizing radiation. The organic compound has a crystalline symmetry of higher order than monoclinic, for example an orthorhombic, trigonal, tetragonal, hexagonal, or cubic symmetry. A photodetector is optically coupled to the scintillating material, and configured to generate electronic signals having pulse shapes based on the photons generated in the scintillating material. A discriminator is coupled to the photon detector, and configured to discriminate between neutrons and gamma rays in the ionizing radiation based on the pulse shapes of the output signals.

High-symmetry organic scintillator systems

Energy Technology Data Exchange (ETDEWEB)

Feng, Patrick L.

2018-03-13

An ionizing radiation detector or scintillator system includes a scintillating material comprising an organic crystalline compound selected to generate photons in response to the passage of ionizing radiation. The organic compound has a crystalline symmetry of higher order than monoclinic, for example an orthorhombic, trigonal, tetragonal, hexagonal, or cubic symmetry. A photodetector is optically coupled to the scintillating material, and configured to generate electronic signals having pulse shapes based on the photons generated in the scintillating material. A discriminator is coupled to the photon detector, and configured to discriminate between neutrons and gamma rays in the ionizing radiation based on the pulse shapes of the output signals.

High-symmetry organic scintillator systems

Science.gov (United States)

Feng, Patrick L.

2018-02-06

An ionizing radiation detector or scintillator system includes a scintillating material comprising an organic crystalline compound selected to generate photons in response to the passage of ionizing radiation. The organic compound has a crystalline symmetry of higher order than monoclinic, for example an orthorhombic, trigonal, tetragonal, hexagonal, or cubic symmetry. A photodetector is optically coupled to the scintillating material, and configured to generate electronic signals having pulse shapes based on the photons generated in the scintillating material. A discriminator is coupled to the photon detector, and configured to discriminate between neutrons and gamma rays in the ionizing radiation based on the pulse shapes of the output signals.

HE upgrade beyond phase 1. Finger scintillator option.

CERN Document Server

Afanasiev, Sergey; Boyarintsev, A.Yu; Emeliantchik, Igor; Golutvin, Igor; Grinyov, B.V; Ershov, Yuri; Levchuk, Leonid; Litomin, Aliaksandr; Malakhov, Alexander; Moisenz, Petr; Popov, V.F; Shumeiko, Nikolai; Smirnov, Vitaly; Sorokin, Pavlo; Zhmurin, Petro

2014-01-01

CMS hadron calorimeters (HB, HE, HO) have been in operation for several years and contributed substantially to the success of the CMS Physics Program. The endcap calorimeter HE suffered more radiation damage than anticipated causing rapid degradation of scintillator segments (tiles) which have a higher radiation flux from secondary particles than HB and HO. A proposal to upgrade of HE calorimeter will provide a solution for survivability at future LHC higher luminosity. A finger-strip plastic scintillator option has many advantages and is a lower cost alternative to keep the excellent HE performance at high luminosity. Measurements and simulations have been performed and this method is a good upgrade strategy.

Dose rate effects in the radiation damage of the plastic scintillators of the CMS Hadron Endcap Calorimeter

CERN Document Server

INSPIRE-00314584

2016-10-07

We present measurements of the reduction of light output by plastic scintillators irradiated in the CMS detector during the 8 TeV run of the Large Hadron Collider and show that they indicate a strong dose rate effect. The damage for a given dose is larger for lower dose rate exposures. The results agree with previous measurements of dose rate effects, but are stronger due to the very low dose rates probed. We show that the scaling with dose rate is consistent with that expected from diffusion effects.

Lead foil wrapping of the plastic scintillators for the gamma ray detection: optical reflector or spectrum intensifier?

International Nuclear Information System (INIS)

Taheri, A.; Askari, M.; Sasanpour, M. Taghan

2017-01-01

This paper studies the effect of lead wrapping on the response of the plastic scintillators as gamma detectors. Experimental tests and Geant4 simulations showed that lead wrapping cannot increase the gamma absorption efficiency of the detector but, as a reflector, it can improve the optical properties of the detector. The reflectivity of the lead foil as an optical reflector was determined equal to 66% using an experimental-simulation combined method. Based on the obtained results, the optical collection efficiency of the detector was also increased about 4% after employing the lead reflector.

Application of plastic scintillation detector in the construction of a monitoring system of radioactive contamination in water

International Nuclear Information System (INIS)

Morgado, Mario Monteiro; Moraes, Marco Antonio P.V. de; Madi Filho, Tufic

1996-01-01

Plastic scintillation detector system has been set up and used gamma ray radiation monitoring purpose in water. In order to determine its relative efficiency characteristics, several conventional solids gamma source has been used in the energy from 60 keV to 133 keV. The efficiency variation in this interval was from 31.8% to 13.2%, respectively and at 661.6 keV was 21.3 % +-0.86%. The sensibility of the system has been determined for use a 131 I radioactive solution as 41.25 kBq/m 3 . (author)

Test of a Fiber Optic-Based LYSO Scintillator Dosimeter in a 60Co Irradiation Chamber

International Nuclear Information System (INIS)

Kim, Tae Hyoung; Kim, Jae Kyung; Park, Jae Woo

2010-01-01

Due to its excellent remote measurability and high spatial resolution, the fiber optic-based radiation dosimeter has been extensively explored for its usability in medical applications by several researchers. In the previous work, we reported the result of our investigation on feasibility of a photon dosimeter constructed with a BGO(Bi 4 Ge 3 O 12 ) or GSO(Gd 2 SiO 5 ) scintillator piece coupled to a plastic optical fiber. The plastic optical fiber had a diameter of 3mm and the scintillator piece was in a cylindrical form with 5mm diameter. The size of the scitillator piece as well as the fiber should be as small as possible for higher spatial resolution, and the radiation hardness should be high enough for stable operation in strong radiation fields. Recently, LYSO(Cerium-doped Lutetium Yttrium Orthosilicate) scintillators, which have much higher light yield and radiation hardness than BGO and GSO, have been commercially available. This paper reports the result of our investigation on dosimetric characteristics of a fiber optic-based dosimeter employing a smaller LYSO scintillator piece with 2mm diameter coupled to a silica optical fiber with 1mm core diameter

Light yield as a function of gas pressure and electric field in gas scintillation proportional counters

International Nuclear Information System (INIS)

Favata, F.; Smith, A.; Bavdaz, M.; Kowalski, T.Z.

1990-01-01

We have investigated the dependence of the scintillation light output for Xe on gas pressure in the range 0.14-1.4 bar, using a gas scintillation proportional counter, in different experimental configurations. We have compared our work with that of previous workers, and have shown that both our results and the results of previous authors are compatible with the intrinsic light output being independent of gas pressure, with any observed dependence being a pure experimental effect due to the spectral response of the various UV detectors used. We also use our experimental data for determining the ratio between the cross section of the Xe 2 ** +Xe→Xe 2 * +Xe reaction and the rate of the Xe 2 ** →2Xe+γ UV reaction. (orig.)

Performance of the first prototype of the CALICE scintillator strip electromagnetic calorimeter

CERN Document Server

Francis, K.; Schlereth, J.; Smith, J.; Xia, L.; Baldolemar, E.; Li, J.; Park, S.T.; Sosebee, M.; White, A.P.; Yu, J.; Eigen, G.; Mikami, Y.; Watson, N.K.; Thomson, M.A.; Ward, D.R.; Benchekroun, D.; Hoummada, A.; Khoulaki, Y.; Apostolakis, J.; Dotti, A.; Folger, G.; Ivantchenko, V.; Ribon, A.; Uzhinskiy, V.; Carloganu, C.; Gay, P.; Manen, S.; Royer, L.; Tytgat, M.; Zaganidis, N.; Blazey, G.C.; Dyshkant, A.; Lima, J.G.R.; Zutshi, V.; Hostachy, J. -Y.; Morin, L.; Cornett, U.; David, D.; Ebrahimi, A.; Falley, G.; Gadow, K.; Goettlicher, P.; Guenter, C.; Hartbrich, O.; Hermberg, B.; Karstensen, S.; Krivan, F.; Krueger, K.; Lutz, B.; Morozov, S.; Morgunov, V.; Neubueser, C.; Reinecke, M.; Sefkow, F.; Smirnov, P.; Terwort, M.; Garutti, E.; Laurien, S.; Lu, S.; Marchesini, I.; Matysek, M.; Ramilli, M.; Briggl, K.; Eckert, P.; Harion, T.; Schultz-Coulon, H. -Ch.; Shen, W.; Stamen, R.; Bilki, B.; Norbeck, E.; Northacker, D.; Onel, Y.; Wilson, G.W.; Kawagoe, K.; Sudo, Y.; Yoshioka, T.; Dauncey, P.D.; Wing, M.; Salvatore, F.; Cortina Gil, E.; Mannai, S.; Baulieu, G.; Calabria, P.; Caponetto, L.; Combaret, C.; Della Negra, R.; Grenier, G.; Han, R.; Ianigro, J-C.; Kieffer, R.; Laktineh, I.; Lumb, N.; Mathez, H.; Mirabito, L.; Petrukhin, A.; Steen, A.; Tromeur, W.; Vander donckt, M.; Zoccarato, Y.; Calvo Alamillo, E.; Fouz, M.-C.; Puerta-Pelayo, J.; Corriveau, F.; Bobchenko, B.; Chadeeva, M.; Danilov, M.; Epifantsev, A.; Markin, O.; Mizuk, R.; Novikov, E.; Popov, V.; Rusinov, V.; Tarkovsky, E.; Besson, D.; Buzhan, P.; Ilyin, A.; Kantserov, V.; Kaplin, V.; Karakash, A.; Popova, E.; Tikhomirov, V.; Kiesling, C.; Seidel, K.; Simon, F.; Soldner, C.; Weuste, L.; Amjad, M.S.; Bonis, J.; Callier, S.; Conforti di Lorenzo, S.; Cornebise, P.; Doublet, Ph.; Dulucq, F.; Fleury, J.; Frisson, T.; van der Kolk, N.; Li, H.; Martin-Chassard, G.; Richard, F.; de la Taille, Ch.; Poeschl, R.; Raux, L.; Rouene, J.; Seguin-Moreau, N.; Anduze, M.; Balagura, V.; Boudry, V.; Brient, J-C.; Cornat, R.; Frotin, M.; Gastaldi, F.; Guliyev, E.; Haddad, Y.; Magniette, F.; Musat, G.; Ruan, M.; Tran, T.H.; Videau, H.; Bulanek, B.; Zacek, J.; Cvach, J.; Gallus, P.; Havranek, M.; Janata, M.; Kvasnicka, J.; Lednicky, D.; Marcisovsky, M.; Polak, I.; Popule, J.; Tomasek, L.; Tomasek, M.; Ruzicka, P.; Sicho, P.; Smolik, J.; Vrba, V.; Zalesak, J.; Belhorma, B.; Ghazlane, H.; Kotera, K.; Ono, H.; Takeshita, T.; Uozumi, S.; Jeans, D.; Chang, S.; Khan, A.; Kim, D.H.; Kong, D.J.; Oh, Y.D.; Goetze, M.; Sauer, J.; Weber, S.; Zeitnitz, C.

2014-11-01

A first prototype of a scintillator strip-based electromagnetic calorimeter was built, consisting of 26 layers of tungsten absorber plates interleaved with planes of 45x10x3 mm3 plastic scintillator strips. Data were collected using a positron test beam at DESY with momenta between 1 and 6 GeV/c. The prototype's performance is presented in terms of the linearity and resolution of the energy measurement. These results represent an important milestone in the development of highly granular calorimeters using scintillator strip technology. This technology is being developed for a future linear collider experiment, aiming at the precise measurement of jet energies using particle flow techniques.

Scintillation detectors, applications in ambient dose rate measurement of ionizing radiation

International Nuclear Information System (INIS)

Harja, C.

1997-01-01

For the task of developing an ambient dose rate measuring probe, the company MAB decided for a design combining an organic plastic scintillator and a secondary electron multiplier. MAB tested a range of available plastic scintillators suitable for this task, and one proved to be particularly good for the intended purpose. This scintillator is a product of the British company NE Technology Ltd. and was specially developed for dosimetry applications, offering the following advantages: The response within the range from 33 keV to 1.3 MeV (Co-60) is much more constant than with combined-design types; there is no afterglow under conditions of excessive load. (orig./CB) [de

TH-CD-201-10: Highly Efficient Synchronized High-Speed Scintillation Camera System for Measuring Proton Range, SOBP and Dose Distributions in a 2D-Plane

International Nuclear Information System (INIS)

Goddu, S; Sun, B; Grantham, K; Zhao, T; Zhang, T; Bradley, J; Mutic, S

2016-01-01

Purpose: Proton therapy (PT) delivery is complex and extremely dynamic. Therefore, quality assurance testing is vital, but highly time-consuming. We have developed a High-Speed Scintillation-Camera-System (HS-SCS) for simultaneously measuring multiple beam characteristics. Methods: High-speed camera was placed in a light-tight housing and dual-layer neutron shield. HS-SCS is synchronized with a synchrocyclotron to capture individual proton-beam-pulses (PBPs) at ∼504 frames/sec. The PBPs from synchrocyclotron trigger the HS-SCS to open its shutter for programmed exposure-time. Light emissions within 30×30×5cm3 plastic-scintillator (BC-408) were captured by a CCD-camera as individual images revealing dose-deposition in a 2D-plane with a resolution of 0.7mm for range and SOBP measurements and 1.67mm for profiles. The CCD response as well as signal to noise ratio (SNR) was characterized for varying exposure times, gains for different light intensities using a TV-Optoliner system. Software tools were developed to analyze ∼5000 images to extract different beam parameters. Quenching correction-factors were established by comparing scintillation Bragg-Peaks with water scanned ionization-chamber measurements. Quenching corrected Bragg-peaks were integrated to ascertain proton-beam range (PBR), width of Spared-Out-Bragg-Peak (MOD) and distal

TH-CD-201-10: Highly Efficient Synchronized High-Speed Scintillation Camera System for Measuring Proton Range, SOBP and Dose Distributions in a 2D-Plane

Energy Technology Data Exchange (ETDEWEB)

Goddu, S; Sun, B; Grantham, K; Zhao, T; Zhang, T; Bradley, J; Mutic, S [Washington University School of Medicine, Saint Louis, MO (United States)

2016-06-15

Purpose: Proton therapy (PT) delivery is complex and extremely dynamic. Therefore, quality assurance testing is vital, but highly time-consuming. We have developed a High-Speed Scintillation-Camera-System (HS-SCS) for simultaneously measuring multiple beam characteristics. Methods: High-speed camera was placed in a light-tight housing and dual-layer neutron shield. HS-SCS is synchronized with a synchrocyclotron to capture individual proton-beam-pulses (PBPs) at ∼504 frames/sec. The PBPs from synchrocyclotron trigger the HS-SCS to open its shutter for programmed exposure-time. Light emissions within 30×30×5cm3 plastic-scintillator (BC-408) were captured by a CCD-camera as individual images revealing dose-deposition in a 2D-plane with a resolution of 0.7mm for range and SOBP measurements and 1.67mm for profiles. The CCD response as well as signal to noise ratio (SNR) was characterized for varying exposure times, gains for different light intensities using a TV-Optoliner system. Software tools were developed to analyze ∼5000 images to extract different beam parameters. Quenching correction-factors were established by comparing scintillation Bragg-Peaks with water scanned ionization-chamber measurements. Quenching corrected Bragg-peaks were integrated to ascertain proton-beam range (PBR), width of Spared-Out-Bragg-Peak (MOD) and distal.

Systematic studies of small scintillators for new sampling calorimeter

Indian Academy of Sciences (India)

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

Pulse shape discrimination in non-aromatic plastics

Energy Technology Data Exchange (ETDEWEB)

Paul Martinez, H.; Pawelczak, Iwona; Glenn, Andrew M.; Leslie Carman, M.; Zaitseva, Natalia; Payne, Stephen

2015-01-21

Recently it has been demonstrated that plastic scintillators have the ability to distinguish neutrons from gamma rays by way of pulse shape discrimination (PSD). This discovery has lead to new materials and new capabilities. Here we report our work with the effects of aromatic, non-aromatic, and mixed aromatic/non-aromatic matrices have on the performance of PSD plastic scintillators.

A feasibility study for the use of BGO scintillator in conjunction with a plastic optical fiber for remote gamma ray dosimetry

International Nuclear Information System (INIS)

Kim, Yong Ho; Seo, Min Woo; Park, Jae Woo

2008-01-01

A feasibility study has been carried out on a remote radiation dosimeter employing a BGO scintillator as the radiation sensing head and a plastic optical fiber as a light pipe. The sensor head is prepared in two sizes: the larger one has the size 4.7mm x 4.7mm x 10mm and the smaller one has the size 2.2mm x 2.2mm x 10mm. A low attenuation plastic optical fiber with 3mm diameter and 10m length is attached to the square surface of the larger scintillator, and the same optical fiber with 2mm diameter is attached to the smaller one. The polished scintillator is wrapped with white Teflon tape, and the fiber is shielded with a thermal shrink tube to block the ambient light. The lights generated in the sensor head are detected by a pulse-type photomultiplier tube module. Co-60 sources with radioactivity of 50μCi and 1mCi are used to test the performance of the constructed dosimeter models. The total number of pulses is measured as a function of the distance from the sensor head to the source. MCNPX simulation is also carried out for the source and dosimeter arrangements to assess the feasibility of the dosimeter model. The dosimeter model measures fairly well the change in the number of pulses as the source-to-detector distance changes, but shows poor capability to measure the pulse height spectrum and source activity. (author)

Scintillator quenching effects observed in the AMS-1 TOF data

Science.gov (United States)

Esquivel, O.; Reyes, T.; Menchaca-Rocha, A.

2001-05-01

An analytical expression for the light output response of plastic scintillators as a function of the energy and the z identity of the incident ion is proposed. The effect of the δ rays is considered in the calculation of the scintillation efficiency. .

Fine-granularity electromagnetic calorimeter using plastic scintillator strip-array

International Nuclear Information System (INIS)

Nagano, A.; Yamauchi, S.; Matsunaga, H.; Kim, S.; Matsumoto, T.; Sekiguchi, K.; Uchida, N.; Yamada, Y.; Yamamoto, S.; Evtoukhovitch, P.; Fujii, Y.; Garutti, E.; Iba, S.; Itoh, S.; Kajino, F.; Kalinnikov, V.; Kallies, W.; Kanzaki, J.; Kawagoe, K.; Kishimoto, S.; Miyata, H.; Mzavia, D.; Nakajima, N.; Nakamura, R.; Ono, H.; Samoilov, V.; Sanchez, A.L.C.; Takeshita, T.; Tamura, Y.; Tsamalaidze, Z.

2006-01-01

For the future linear collider calorimetry, fine-granularity is indispensable for energy measurements based on particle flow algorithm, which could achieve better energy resolution for jets than the conventional method. To explore the possibility for such a calorimeter using scintillator, an electromagnetic calorimeter test module, made of scintillator-strips and lead plates, was constructed and tested with test beams. Performance of the test module is presented in this article, in terms of the shower profile studies as well as energy and spatial measurements

Water-equivalent one-dimensional scintillating fiber-optic dosimeter for measuring therapeutic photon beam

International Nuclear Information System (INIS)

Moon, Jinsoo; Won Jang, Kyoung; Jae Yoo, Wook; Han, Ki-Tek; Park, Jang-Yeon; Lee, Bongsoo

2012-01-01

In this study, we fabricated a one-dimensional scintillating fiber-optic dosimeter, which consists of 9 scintillating fiber-optic dosimeters, septa, and PMMA blocks for measuring surface and percentage depth doses of a therapeutic photon beam. Each dosimeter embedded in the 1-D scintillating fiber-optic dosimeter is composed of square type organic scintillators and plastic optical fibers. Also black PVC films are used as septa to minimize cross-talk between the scintillating fiber-optic dosimeters. To construct a dosimeter system, a 1-D scintillating fiber-optic dosimeter and a CMOS image sensor were combined with 20 m-length plastic optical fibers. Using the dosimeter system, we measured surface and percentage depth doses of 6 and 15 MV photon beams and compared the results with those of EBT films and an ionization chamber. - Highlights: ► Fabrication of a one-dimensional scintillating fiber-optic dosimeter. ► The one-dimensional scintillating fiber-optic dosimeter has 9 scintillating fiber-optic dosimeters. ► Measurements of surface and percentage depth doses of a therapeutic photon beam. ► The results were compared with those of EBT films and an ionization chamber.

Detection of Beta-rays by using Plastic Scintillating Fibers

International Nuclear Information System (INIS)

Park, Chan Hee

2005-02-01

Optical fibers have been used as sensing materials in various nuclear applications. Optical fiber sensors have proven to present several advantages as compared with other conventional sensors. They can be prepared in very small sizes and they are light enough to be easily put into very narrow channels such as between nuclear to be easily put into very narrow channels such as between nuclear fuel rods. No electrical power is needed to the sensor part so they are less susceptible to troubles in harsh environments such as underground and underwater. Optical fiber sensors cost relatively cheap to make, so that they are more suitable for multi-point radiation monitoring such as in nuclear power plants, accelerators, fusion study facilities. If one develops radiation sensors using scintillating optical fibers, that can directly measure the concentration of 3 H or 14 C in radioactive liquid, they can be useful tools to substitute the current liquid scintillation counters. They can be also used to measure the radioactivity of liquid radioactive wastes by dipping into the liquid wastes. Recently, several new scintillating materials of high density and low hygroscopicity have been found, and they can be transformed into good radiation-detection tools when they are combined with optical fibers. In this study, we have used commercially available plastic scintillating fibers of Bicron model BCF-12 (0.5mm, 1mm in diameter) to detect beta rays emitted from 3 H, 14 C. Several types of radiation sensors were constructed : each was constructed with thirty strands of the fibers being packed an aluminum tube. The optical signals generated inside the fiber bundle were converted into electrical pluses by a photomultiplier tube(PMT). The pulses were counted either through a non-coincidence circuit or a coincidence circuit. Two types of sensors were constructed for the non-coincidence counting. The open type (sensor A) is a sensor for which one end of the fibers is open and the other end

Buried plastic scintillator muon telescope (BATATA)

Energy Technology Data Exchange (ETDEWEB)

Alfaro, R. [Inst. de Fisica, Universidad Nacional Autonoma de Mexico, Mexico, D.F., C.P. 04510 (Mexico); De Donato, C.; D' Olivo, J.C.; Guzman, A.; Medina-Tanco, G. [Inst. de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Mexico, D.F., C.P. 04510 (Mexico); Moreno Barbosa, E. [Fac. de Ciencias Fisico Matematicas, Benemerita Universidad Autonoma de Puebla, Puebla (Mexico); Paic, G.; Patino Salazar, E. [Inst. de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Mexico, D.F., C.P. 04510 (Mexico); Salazar Ibarguen, H. [Fac. de Ciencias Fisico Matematicas, Benemerita Universidad Autonoma de Puebla, Puebla (Mexico); Sanchez, F.A., E-mail: federico.sanchez@nucleares.unam.m [Inst. de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Mexico, D.F., C.P. 04510 (Mexico); Supanitsky, A.D. [Inst. de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Mexico, D.F., C.P. 04510 (Mexico); Valdes-Galicia, J.F. [Inst. de Geofisica, Universidad Nacional Autonoma de Mexico, Mexico, D.F., C.P. 04510 (Mexico); Vargas Trevino, A.D.; Vergara Limon, S. [Fac. de Ciencias de la Electronica, Benemerita Universidad Autonoma de Puebla, Puebla (Mexico); Villasenor, L.M. [Inst. de Fisica y Matematicas, Universidad Michoacana de San Nicolas Hidalgo Morelia (Mexico); Observatorio Pierre Auger, Av. San Martin Norte 304 (5613) Malarguee, Prov. Mendoza (Argentina)

2010-05-21

Muon telescopes have multiple applications in the area of cosmic ray research. We are currently building such a detector with the objective of comparing the ground penetration of muon vs. electron-gamma signals originated in cosmic ray showers. The detector is composed by a set of three parallel dual-layer scintillator planes, buried at fixed depths ranging from 120 to 600g/cm{sup 2}. Each layer is 4m{sup 2} and is composed by 49 rectangular strips of 4cmx2m, oriented at a 90{sup 0} angle with respect to its companion layer, which gives an xy-coincidence pixel of 4x4cm{sup 2}. The scintillators are MINOS extruded polystyrene strips, with an embedded Bicron BC92 wavelength shifting (WLS) fibers, of 1.5 mm in diameter. Light is collected by Hamamatsu H7546B multi-anode PMTs of 64 pixels. The front-end (FE) electronics works in counting mode and signals are transmitted to the surface DAQ stage using low-voltage differential signaling (LVDS). Any strip signal above threshold opens a GPS-tagged 2{mu}s data collection window. Data, including signal and background, are acquired by a system of FPGA (Spartan 2E) boards and a single-board computer (TS7800).

Buried plastic scintillator muon telescope (BATATA)

International Nuclear Information System (INIS)

Alfaro, R.; De Donato, C.; D'Olivo, J.C.; Guzman, A.; Medina-Tanco, G.; Moreno Barbosa, E.; Paic, G.; Patino Salazar, E.; Salazar Ibarguen, H.; Sanchez, F.A.; Supanitsky, A.D.; Valdes-Galicia, J.F.; Vargas Trevino, A.D.; Vergara Limon, S.; Villasenor, L.M.

2010-01-01

Muon telescopes have multiple applications in the area of cosmic ray research. We are currently building such a detector with the objective of comparing the ground penetration of muon vs. electron-gamma signals originated in cosmic ray showers. The detector is composed by a set of three parallel dual-layer scintillator planes, buried at fixed depths ranging from 120 to 600g/cm 2 . Each layer is 4m 2 and is composed by 49 rectangular strips of 4cmx2m, oriented at a 90 0 angle with respect to its companion layer, which gives an xy-coincidence pixel of 4x4cm 2 . The scintillators are MINOS extruded polystyrene strips, with an embedded Bicron BC92 wavelength shifting (WLS) fibers, of 1.5 mm in diameter. Light is collected by Hamamatsu H7546B multi-anode PMTs of 64 pixels. The front-end (FE) electronics works in counting mode and signals are transmitted to the surface DAQ stage using low-voltage differential signaling (LVDS). Any strip signal above threshold opens a GPS-tagged 2μs data collection window. Data, including signal and background, are acquired by a system of FPGA (Spartan 2E) boards and a single-board computer (TS7800).

Development of multi-color scintillator based X-ray image intensifier

International Nuclear Information System (INIS)

Nittoh, Koichi; Konagai, Chikara; Noji, Takashi

2004-01-01

A multi-color scintillator based high-sensitive, wide dynamic range and long-life X-ray image intensifier has been developed. An europium activated Y 2 O 2 S scintillator, emitting red, green and blue photons of different intensities, is utilized as the output fluorescent screen of the intensifier. By combining this image intensifier with a suitably tuned high sensitive color CCD camera, it is possible for a sensitivity of the red color component to become six times higher than that of the conventional image intensifier. Simultaneous emission of a moderate green color and a weak blue color covers different sensitivity regions. This widens the dynamic range, by nearly two orders of ten. With this image intensifier, it is possible to image simultaneously complex objects containing various different X-ray transmission from paper, water or plastic to heavy metals. This high sensitivity intensifier, operated at lower X-ray exposure, causes less degradation of scintillator materials and less colorization of output screen glass, and thus helps achieve a longer lifetime. This color scintillator based image intensifier is being introduced for X-ray inspection in various fields

A high-pressure hydrogen time projection chamber for the MuCap experiment

Energy Technology Data Exchange (ETDEWEB)

Egger, J.; Fahrni, D.; Hildebrandt, M.; Hofer, A.; Meier, L.; Petitjean, C. [Paul Scherrer Institute, Villigen PSI (Switzerland); Andreev, V.A.; Ganzha, V.A.; Kravtsov, P.A.; Krivshich, A.G.; Maev, E.M.; Maev, O.E.; Petrov, G.; Semenchuk, G.G.; Vasilyev, A.A.; Vorobyov, A.A.; Vznuzdaev, M.E. [Petersburg Nuclear Physics Institute, Gatchina (Russian Federation); Banks, T.I. [University of California, Department of Physics, Berkeley, California (United States); Clayton, S.M. [University of Illinois at Urbana-Champaign, Department of Physics, Urbana, Illinois (United States); Gray, F.E. [University of California, Department of Physics, Berkeley, California (United States); Regis University, Department of Physics and Computational Science, Denver, Colorado (United States); University of Washington, Department of Physics, Seattle, Washington (United States); Kammel, P.; Kiburg, B.; Winter, P. [University of Illinois at Urbana-Champaign, Department of Physics, Urbana, Illinois (United States); University of Washington, Department of Physics, Seattle, Washington (United States); Lauss, B. [Paul Scherrer Institute, Villigen PSI (Switzerland); University of California, Department of Physics, Berkeley, California (United States)

2014-10-15

The MuCap experiment at the Paul Scherrer Institute performed a high-precision measurement of the rate of the basic electroweak process of nuclear muon capture by the proton, μ{sup -} + p → n + ν{sub μ}. The experimental approach was based on the use of a time projection chamber (TPC) that operated in pure hydrogen gas at a pressure of 10bar and functioned as an active muon stopping target. The TPC detected the tracks of individual muon arrivals in three dimensions, while the trajectories of outgoing decay (Michel) electrons were measured by two surrounding wire chambers and a plastic scintillation hodoscope. The muon and electron detectors together enabled a precise measurement of the μp atom's lifetime, from which the nuclear muon capture rate was deduced. The TPC was also used to monitor the purity of the hydrogen gas by detecting the nuclear recoils that follow muon capture by elemental impurities. This paper describes the TPC design and performance in detail. (orig.)

Useful effectiveness of plastic pipes for gas pipelines operating at low pressure

Energy Technology Data Exchange (ETDEWEB)

Zayutsev, K I

1976-06-01

Because a significant portion of the feeder lines in the Soviet union operate at relatively low pressures up to 75 to 150 psi, it is economically feasible to replace the conventional pipeline material (steel) with plastic. Cost savings result from lower material costs and ease of laying plastic pipe. Because of stiffness and corrosion requirements, the steel pipe used for these low-pressure pipelines is much thicker than needed to withstand the pressure used. Data are tabulated on the comparative costs and manpower requirements for the construction of 1 km of steel, polyvinyl chloride, and polyethylene gas pipelines ranging in diameter from 3 to 14 in. Generally, the plastic pipelines required 15 to 30% less man-days and were 20 to 35% lower in cost to build. The plastic pipelines can operate at 150 to 175 psi pressure and at temperatures up to 100 to 140/sup 0/F. In research conducted at VNIIST (All-Union Research Institute for the Construction of Trunk Pipelines) on plastic pipelines, a 2.5-mile test section has been operating successfully for 2 years, and new techniques and equipment for joining plastic pipe up to 25-in. diameter are being developed.

Fine grained hodoscopes based on scintillating optical fibres

International Nuclear Information System (INIS)

Borenstein, S.R.; Strand, R.C.

1985-01-01

This is a description of the development and testing of scintillating optical fibers for use in a fine grained hodoscope for experiments in High Energy Physics. After a brief discussion of the need for such a device in experiments in high rate environments, a description is given of the process of drawing and cladding plastic scintillator to form scintillating optical fibers. This is followed by a description of the test procedures used to evaluate the resultant fibers both in the laboratory and at the accelerator. A discussion of three possible readout schemes then follows. These are individual photomultiplier tubes, avalanche photo-diodes and microchannel plates with segmented anodes. The results of this study are then presented. The present status of the project is then summarized, in which it is pointed out that significant improvement in useful fiber length has been achieved as a result of this development program. The difficulty of quality control in fiber production remains a serious limitation, and a satisfactory readout scheme with good optical coupling between many hodoscope elements and photodetectors has yet to be achieved. (orig.)

Effects of Friction and Anvil Design on Plastic Deformation during the Compression Stage of High-Pressure Torsion

Energy Technology Data Exchange (ETDEWEB)

Song, Yuepeng; Chen, Miaomiao; Xu, Baoyan; Guo, Jing; Xu, Lingfeng; Wang, Zheng [Mechanical and Electronic Engineering College, Tai’an (China); Gao, Dongsheng [Shandong Provincial Key Laboratory of Horticultural Machineries and Equipments, Tai’an (China); Kim, Hyoung Seop [Department of Materials Science and Engineering, Pohang (Korea, Republic of)

2016-11-15

Herein, we report the results of our investigation on the effect of friction and anvil design on the heterogeneous plastic-deformation characteristics of copper during the compressive stage of high-pressure torsion (HPT), using the finite element method. The results indicate that the friction and anvil geometry play important roles in the homogeneity of the deformation. These variables affect the heterogeneous level of strain in the HPT compressed disks, as well as the flash in the disk edge region. The heterogeneous plastic deformation of the disks becomes more severe with the increasing depth of the cavity, as anvil angle and friction coefficient increase. However, the homogeneity increases with increases in the wall angle. The length of flash and the area of the dead metal zone increase with the depth of the cavity, while they decrease at a wall angle of 180°.

Plastic scintillation dosimetry: comparison of three solutions for the Cerenkov challenge

Energy Technology Data Exchange (ETDEWEB)

Liu, P Z Y; Suchowerska, N; Lambert, J; Abolfathi, P; McKenzie, D R, E-mail: pliu@physics.usyd.edu.au [School of Physics, University of Sydney, NSW 2006 (Australia)

2011-09-21

In scintillation dosimetry, a Cerenkov background signal is generated when a conventional fibre optic is exposed to radiation produced by a megavoltage linear accelerator. Three methods of measuring dose in the presence of Cerenkov background are compared. In the first method, a second background fibre is used to estimate the Cerenkov signal in the signal fibre. In the second method, a colour camera is used to measure the combined scintillation and Cerenkov light in two wavelength ranges and a mathematical process is used to extract the scintillation signal. In the third method, a hollow air core light guide is used to carry the scintillation signal through the primary radiation field. In this paper, the strengths and weaknesses of each dosimetry system are identified and recommendations for the optimum method for common clinical dosimetry situations are made.

POSSuMUS: a position sensitive scintillating muon SiPM detector

CERN Document Server

Ruschke, Alexander

The development of a modular designed large scale scintillation detector with a two-dimensional position sensitivity is presented in this thesis. This novel POsition Sensitive Scintillating MUon SiPM Detector is named POSSuMUS. The POSSuMUS detector is capable to determine the particle’s position in two space dimensions with a fast trigger capability. Each module is constructed from two trapezoidal shaped plastic scintillators to form one rectangular shaped detector module. Both trapezoids are optically insulated against each other. In both trapezoids the scintillation light is collected by plastic fibers and guided towards silicon photomultipliers (SiPMs). SiPMs are light sensors which are capable to detect even smallest amounts of light. By combining several detector modules, position sensitive areas from 100 cm2 to few m2 are achievable with few readout channels. Therefore, POSSuMUS provides a cost effective detector concept. The position sensitivity along the trapezoidal geometry of one detector module ...

Performance evaluation of X-ray CT using visible scintillation light

International Nuclear Information System (INIS)

Kodama, Kiyoyuki; Hamada, Minoru; Suzuki, Tamotsu; Hashimoto, Masatoshi; Hanada, Takashi; Ide, Tatsuya; Maruyama, Koichi

2004-01-01

We proposed a new method of performance evaluation for X-ray CT using visible scintillation light and examined its usefulness in this study. When we scanned a plastic scintillator disk in a gantry opening of the X-ray CT, we could observe visible scintillation light. The rotation of the light-emitting area of the disk corresponded to that of the X-ray tube. We were able to record the scintillation light by digital video camera. By analyzing the area of visible scintillation light, the rotation speed of the X-ray tube, angular spread of the X-ray beam, uniformity of the incident X-rays, and change in X-ray energy were measured. No other method is available to obtain the above parameters of X-ray CT during a single CT scan. In the measurements of the uniformity of incident X-rays and change of X-ray energy, our method showed good accuracy in detecting the attenuation caused by the couch between the X-ray tube and the plastic scintillator disc. The proposed method is inexpensive and easy-to-use. We conclude that the method is a useful tool for performance evaluation as well as a maintenance tool for X-ray CT. (author)

Microfluidic Scintillation Detectors for High Energy Physics

CERN Document Server

Maoddi, Pietro; Mapelli, Alessandro

This thesis deals with the development and study of microfluidic scintillation detectors, a technology of recent introduction for the detection of high energy particles. Most of the interest for such devices comes from the use of a liquid scintillator, which entails the possibility of changing the active material in the detector, leading to increased radiation resistance. A first part of the thesis focuses on the work performed in terms of design and modelling studies of novel prototype devices, hinting to new possibilities and applications. In this framework, the simulations performed to validate selected designs and the main technological choices made in view of their fabrication are addressed. The second part of this thesis deals with the microfabrication of several prototype devices. Two different materials were studied for the manufacturing of microfluidic scintillation detectors, namely the SU-8 photosensitive epoxy and monocrystalline silicon. For what concerns the former, an original fabrication appro...

Effects of detector-source distance and detector bias voltage variations on time resolution of general purpose plastic scintillation detectors.

Science.gov (United States)

Ermis, E E; Celiktas, C

2012-12-01

Effects of source-detector distance and the detector bias voltage variations on time resolution of a general purpose plastic scintillation detector such as BC400 were investigated. (133)Ba and (207)Bi calibration sources with and without collimator were used in the present work. Optimum source-detector distance and bias voltage values were determined for the best time resolution by using leading edge timing method. Effect of the collimator usage on time resolution was also investigated. Copyright © 2012 Elsevier Ltd. All rights reserved.

Stopped cosmic-ray muons in plastic scintillators on the surface and at the depth of 25 m.w.e

International Nuclear Information System (INIS)

Maletić, D; Dragić, A; Banjanac, R; Joković, D; Veselinović, N; Udovicić, V; Savić, M; Anicin, I; Puzović, J

2013-01-01

Cosmic ray muons stopped in 5 cm thick plastic scintillators at surface and at depth of 25 m.w.e are studied. Apart from the stopped muon rate we measured the spectrum of muon decay electrons and the degree of polarization of stopped muons. Preliminary results for the Michel parameter yield values lower than the currently accepted one, while the asymmetry between the numbers of decay positrons registered in the upper and lower hemispheres appear higher than expected on the basis of numerous earlier studies.

TH-CD-201-04: A Study of Cherenkov Light Generated and Collected in Plastic Scintillation Detector

Energy Technology Data Exchange (ETDEWEB)

Archambault, L [CHUQ Pavillon Hotel-Dieu de Quebec, Quebec, QC (Canada); Papaconstadopoulos, P [McGill Montreal General Hospital, Montreal, QC (Canada); Seuntjens, J [McGill Montreal General Hospital, Montreal, QC (Canada); McGill University, Montreal, Quebec (Canada); Bouchard, H [CHUM-Hospital Notre-Dame, Montreal, QC (Canada)

2016-06-15

Purpose: To study Cherenkov light emission in plastic scintillation detectors (PSDs) from a theoretical point of view to identify situations that may arise where the calibration coefficient obtained in one condition is not applicable to another condition. By identifying problematic situations, we hope to provide guidance on how to confidently use PSDs. Methods: Cherenkov light emission in PSD was modelled using basic physical principles. In particular, changes in refractive index as a function of wavelength were accounted for using the Sellmeier empirical equation. Both electron and photon beams were considered. For photons, realistic distributions of secondary charged particles were calculated using Klein-Nishina’s formula. Cherenkov production and collection in PSDs were studied for a range of parameters including beam energy, charged particle momentum distribution, detector orientation and material composition. Finally, experimental validation was made using a commercial plastic scintillation detector. Results: In specific situations, results show that the Cherenkov spectrum coupled in the PSD can deviate from its expected behaviour (i.e. one over the square of the wavelength). In these cases were the model is realistic it is possible to see a peak wavelength instead of a monotonically decreasing function. Consequences of this phenomenon are negligible when the momentum of charged particle is distributed randomly, but in some clinically relevant cases, such as an electron beam at depth close to R50 or for photon beams with minimal scatter component, the value of the calibration coefficient can be altered. Experimental tests with electron beams showed changes in the Cherenkov light ratio, the parameter used in the calibration of PSDs, up to 2–3% depending on the PSD orientation. Conclusion: This work is the first providing a physical explanation for apparent change in PSD calibration coefficient. With this new information at hand, it will be possible to

Set of counts by scintillations for atmospheric samplings

International Nuclear Information System (INIS)

Appriou, D.; Doury, A.

1962-01-01

The author reports the development of a scintillation-based counting assembly with the following characteristics: a photo-multiplier with a wide photo-cathode, a thin plastic scintillator for the counting of beta + alpha (and possibility of mounting an alpha scintillator), a relatively small own motion with respect to activities to be counted, a weakly varying efficiency. The authors discuss the counting objective, present equipment tests (counter, proportional amplifier and pre-amplifier, input drawer). They describe the apparatus operation, discuss the selection of scintillators, report the study of the own movement (electron-based background noise, total background noise, background noise reduction), discuss counts (influence of the external source, sensitivity to alpha radiations, counting homogeneity, minimum detectable activity) and efficiencies

Pulse shape discrimination with scintillation detectors

International Nuclear Information System (INIS)

Winyard, R.A.

A quantitative study of pulse shape discrimination with scintillation counters has been undertaken using a crossover timing technique. The scintillators investigated included experimental and commercial liquids and plastics in addition to inorganic phosphors. The versatility of the pulse shape discrimination system has been demonstrated by extending the measurements to investigate phoswiches and liquids loaded with radioactive materials and by its application to the suppression of unwanted backgrounds in delayed coincidence counting for the measurement of nuclear half-lives and isotope identification have been carried out. (author)

Plane strain analytical solutions for a functionally graded elastic-plastic pressurized tube

International Nuclear Information System (INIS)

Eraslan, Ahmet N.; Akis, Tolga

2006-01-01

Plane strain analytical solutions to functionally graded elastic and elastic-plastic pressurized tube problems are obtained in the framework of small deformation theory. The modulus of elasticity and the uniaxial yield limit of the tube material are assumed to vary radially according to two parametric parabolic forms. The analytical plastic model is based on Tresca's yield criterion, its associated flow rule and ideally plastic material behaviour. Elastic, partially plastic and fully plastic stress states are investigated. It is shown that the elastoplastic response of the functionally graded pressurized tube is affected significantly by the material nonhomogeneity. Different modes of plasticization may take place unlike the homogeneous case. It is also shown mathematically that the nonhomogeneous elastoplastic solution presented here reduces to that of a homogeneous one by appropriate choice of the material parameters

AN EVALUATION OF THE BASIC CHARACTERISTICS OF A PLASTIC SCINTILLATING FIBRE DETECTOR IN CT RADIATION FIELDS.

Science.gov (United States)

Terasaki, Kento; Fujibuchi, Toshioh; Toyoda, Takatoshi; Yoshida, Yutaka; Akasaka, Tsutomu; Nohtomi, Akihiro; Morishita, Junji

2016-12-01

The ionisation chamber for computed tomography (CT) is an instrument that is most commonly used to measure the computed tomography dose index. However, it has been reported that the 10 cm effective detection length of the ionisation chamber is insufficient due to the extent of the dose distribution outside the chamber. The purpose of this study was to estimate the basic characteristics of a plastic scintillating fibre (PSF) detector with a long detection length of 50 cm in CT radiation fields. The authors investigated position dependence using diagnostic X-ray equipment and dependencies for energy, dose rate and slice thickness using an X-ray CT system. The PSF detector outputs piled up at a count rate of 10 000 counts ms -1 in dose rate dependence study. With calibration, this detector may be useful as a CT dosemeter with a long detection length except for the measurement at high dose rate. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Elastic-plastic behaviour of thick-walled containers considering plastic compressibility

International Nuclear Information System (INIS)

Betten, J.; Frosch, H.G.

1983-01-01

In this paper the elastic-plastic behaviour of thick-walled pressure vessels with internal and external pressure is studied. To describe the mechanical behaviour of isotropic, plastic compressible materials we use a plastic potential which is a single-valued function of the principle stresses. For cylinders and spheres an analytic expression for the computation of stresses and residual stresses is specified. Afterwards the strains are calculated by using the finite difference method. Some examples will high-light the influence of the plastic compressibility on the behaviour of pressure vessels. (orig.) [de

Using neutrons to measure keV temperatures in highly compressed plastic at multi-Gbar pressures

Science.gov (United States)

Nilsen, J.; Bachmann, B.; Zimmerman, G. B.; Hatarik, R.; Döppner, T.; Swift, D.; Hawreliak, J.; Collins, G. W.; Falcone, R. W.; Glenzer, S. H.; Kraus, D.; Landen, O. L.; Kritcher, A. L.

2016-12-01

We have designed an experiment for the National Ignition Facility to measure the Hugoniot of materials such as plastic at extreme pressures. The design employs a strong spherically converging shock launched through a solid ball of material using a hohlraum radiation drive. The shock front conditions can be characterized using X-ray radiography until background from shock coalescence overtakes the backlit signal. Shock coalescence at the center is predicted to reach tens of Gbars and can be further characterized by measuring the X-ray self-emission and 2.45 MeV neutrons emitted from the shock flash region. In this simulation design work the standard plastic sphere is replaced with a deuterated polyethylene sphere, CD2, that reaches sufficiently high densities and temperatures in the central hot spot to produce neutrons from Deuterium-Deuterium (DD) fusion reactions that can be measured by a neutron time of flight spectrometer (nTOF) and act as a temperature diagnostic. This paper focuses on the design of these experiments, based on an extensive suite of radiation-hydrodynamics simulations, and the interpretation of the predicted DD neutron signals. The simulations predict mean temperatures of 1 keV in the central hot spot with mean densities of 33 g/cc and mean pressures of 25 Gbar. A preliminary comparison with early experimental results looks promising with an average ion temperature of 1.06 ± 0.15 keV in the central hot spot estimated from the nTOF spectral width and measured neutron yield of 7.0 (±0.5) × 109 DD neutrons.

Development of radiation hard scintillators

International Nuclear Information System (INIS)

Markley, F.; Woods, D.; Pla-Dalmau, A.; Foster, G.; Blackburn, R.

1992-05-01

Substantial improvements have been made in the radiation hardness of plastic scintillators. Cylinders of scintillating materials 2.2 cm in diameter and 1 cm thick have been exposed to 10 Mrads of gamma rays at a dose rate of 1 Mrad/h in a nitrogen atmosphere. One of the formulations tested showed an immediate decrease in pulse height of only 4% and has remained stable for 12 days while annealing in air. By comparison a commercial PVT scintillator showed an immediate decrease of 58% and after 43 days of annealing in air it improved to a 14% loss. The formulated sample consisted of 70 parts by weight of Dow polystyrene, 30 pbw of pentaphenyltrimethyltrisiloxane (Dow Corning DC 705 oil), 2 pbw of p-terphenyl, 0.2 pbw of tetraphenylbutadiene, and 0.5 pbw of UVASIL299LM from Ferro

High-resolution tracking using large capillary bundles filled with liquid scintillator

CERN Document Server

Annis, P; Benussi, L; Bruski, N; Buontempo, S; Currat, C; D'Ambrosio, N; Van Dantzig, R; Dupraz, J P; Ereditato, A; Fabre, Jean-Paul; Fanti, V; Feyt, J; Frekers, D; Frenkel, A; Galeazzi, F; Garufi, F; Goldberg, J; Golovkin, S V; Gorin, A M; Grégoire, G; Harrison, K; Höpfner, K; Holtz, K; Konijn, J; Kozarenko, E N; Kreslo, I E; Kushnirenko, A E; Liberti, B; Martellotti, G; Medvedkov, A M; Michel, L; Migliozzi, P; Mommaert, C; Mondardini, M R; Panman, J; Penso, G; Petukhov, Yu P; Rondeshagen, D; Siegmund, W P; Tyukov, V E; Van Beek, G; Vasilchenko, V G; Vilain, P; Visschers, J L; Wilquet, G; Winter, Klaus; Wolff, T; Wörtche, H J; Wong, H; Zimyn, K V

2000-01-01

We have developed large high-resolution tracking detectors based on glass capillaries filled with organic liquid scintillator of high refractive index. These liquid-core scintillating optical fibres act simultaneously as detectors of charged particles and as image guides. Track images projected onto the readout end of a capillary bundle are visualized by an optoelectronic chain consisting of a set of image-intensifier tubes followed by a photosensitive CCD or by an EBCCD camera. Two prototype detectors, each composed of \\hbox{$\\approx 10^6$} capillaries with \\hbox{20$-$25 $\\mu$m} diameter and \\hbox{0.9$-$1.8 m} length, have been tested, and a spatial resolution of the order of \\hbox{20$-$40 $\\mu$m} has been attained. A high scintillation efficiency and a large light-attenuation length, in excess of 3 m, was achieved through special purification of the liquid scintillator. Along the tracks of minimum-ionizing particles, the hit densities obtained were $\\sim$ 8 hits/mm at the readout window, and \\hbox{$\\sim$ 3 ...

A SiPM-based scintillator prototype for the upgrade of the Pierre Auger Observatory

Energy Technology Data Exchange (ETDEWEB)

Schumacher, Johannes; Bretz, Thomas; Hebbeker, Thomas; Kemp, Julian; Meissner, Rebecca; Middendorf, Lukas; Niggemann, Tim; Peters, Christine [III. Physikalisches Institut A, RWTH Aachen University (Germany); Collaboration: Pierre-Auger-Collaboration

2016-07-01

Plastic scintillator-based detectors are simple and yet powerful instruments, commonly used in particle physics experiments. These detectors are also planned to be installed at the Pierre Auger Observatory as part of the upgrade called AugerPrime. Here, a single detector module will consist of several large-sized scintillator bars. Embedded wavelength shifting fibres read out the scintillation light and are coupled to a single photo-sensitive device. We investigate the application of silicon photomultipliers (SiPMs) in this scope, which benefits from high photon detection efficiency and stability. We show the performance of a SiPM-based prototype device installed in the 2 m{sup 2} detector ASCII - an early prototype of the scintillating detector planned for AugerPrime. We focus on the electronics, the optical coupling and the in situ calibration. As ASCII has been operating with SiPMs for several months now, we also highlight first high-energy events seen in coincidence with the Surface Detector of the Pierre Auger Observatory.

Plastic limit pressure of spherical vessels with combined hardening involving large deformation

International Nuclear Information System (INIS)

Leu, S.-Y.; Liao, K.-C.; Lin, Y.-C.

2014-01-01

The paper aims to investigate plastic limit pressure of spherical vessels of nonlinear combined isotropic/kinematic hardening materials. The Armstrong-Frederick kinematic hardening model is adopted and the Voce hardening law is incorporated for isotropic hardening behavior. Analytically, we extend sequential limit analysis to deal with combined isotropic/kinematic hardening materials. Further, exact solutions of plastic limit pressure were developed analytically by conducting both static and kinematic limit analysis. The onset of instability was also derived and solved iteratively by Newton's method. Numerically, elastic–plastic analysis is also performed by the commercial finite-element code ABAQUS incorporated with the user subroutine UMAT implemented with user materials of combined hardening. Finally, the problem formulation and the solution derivations presented here are validated by a very good agreement between the numerical results of exact solutions and the results of elastic–plastic finite-element analysis by ABAQUS. -- Highlights: • Sequential limit analysis is extended to consider combined hardening. • Exact solutions of plastic limit pressure are developed. • The onset of instability of a spherical vessel is derived and solved numerically

Calorimetry using organic scintillators, 'a sideways perspective'.

Energy Technology Data Exchange (ETDEWEB)

Proudfoot, J.

1999-09-10

Over the last two decades, calorimetry baaed on organic scintillators has developed into an excellent technology for many experimental situations in high energy physics. The primary difficulty, that of extracting the light signals, has benefited from two milestone innovations. The first was the use of wavelength-shifting bars to allow light to be efficiently collected from large areas of scintillator and then readily piped to a readout device. The second of these was the extension of this approach to plastic wavelength-shifting optical fibers whose great flexibility and small diameter allowed a minimum of detector volume to be compromised by the read-out. These two innovations coupled with inventiveness have produced many varied and successful calorimeters. Equal response to both hadronic and electromagnetic showers can be realized in scintillator-based calorimeters. However, in general this is not the case and it is likely that in the search for greater performance, in the future, combined tracking and calorimeter systems will be required.

Spectral Analysis Method of Plastic Scintillator-based Radiation Detector against Nuclear/Radiological Terrorism

International Nuclear Information System (INIS)

Kwak, Sung-Woo; Yoo, Ho-Sik; Jang, Sung Soon; Kim, Jung-Soo; Yoon, Wan-Ki

2008-01-01

In these days, the threats relating to nuclear or radioactive materials have become a matter of internationally increased grave concern. A plastic scintillation detector in radiation portal monitoring (RPM) application has been used to detect radioactive sources in steel scrap entering reprocessing facilities, and to detect illicit transport of radioactive material across border ports-of-entry. The detection systems for RPM application usually are large and can not easily be moved to a different location. For some situations, an inconspicuous and mobile system for the radioactive or nuclear material during road transport is needed. The mobile radiation detection system has employed a NaI- based radiation detector to detect and identify the material hidden in vehicle. There are some operational constraints - short measuring time, weak activity due to heavy shield of illegal source, long distance - of inspection system in such nuclear security applications. Due to these constraints, large area sensor is required to maximize its sensitivity. Large NaI material, however, is extremely expensive. In designing a radiation detector for prevention of illicit trafficking of nuclear or radioactive materials, the trade-off should be carefully optimized between performance and cost in order to achieve cost-effective inspection system. For the cost-effective mobile radiation detection system, this paper describes new spectral analysis method to use the crude spectroscopic information available from a plastic detector to discriminate other man-made radiation source from NORM

Characterization of the Ionospheric Scintillations at High Latitude using GPS Signal

Science.gov (United States)

Mezaoui, H.; Hamza, A. M.; Jayachandran, P. T.

2013-12-01

Transionospheric radio signals experience both amplitude and phase variations as a result of propagation through a turbulent ionosphere; this phenomenon is known as ionospheric scintillations. As a result of these fluctuations, Global Positioning System (GPS) receivers lose track of signals and consequently induce position and navigational errors. Therefore, there is a need to study these scintillations and their causes in order to not only resolve the navigational problem but in addition develop analytical and numerical radio propagation models. In order to quantify and qualify these scintillations, we analyze the probability distribution functions (PDFs) of L1 GPS signals at 50 Hz sampling rate using the Canadian High arctic Ionospheric Network (CHAIN) measurements. The raw GPS signal is detrended using a wavelet-based technique and the detrended amplitude and phase of the signal are used to construct probability distribution functions (PDFs) of the scintillating signal. The resulting PDFs are non-Gaussian. From the PDF functional fits, the moments are estimated. The results reveal a general non-trivial parabolic relationship between the normalized fourth and third moments for both the phase and amplitude of the signal. The calculated higher-order moments of the amplitude and phase distribution functions will help quantify some of the scintillation characteristics and in the process provide a base for forecasting, i.e. develop a scintillation climatology model. This statistical analysis, including power spectra, along with a numerical simulation will constitute the backbone of a high latitude scintillation model.

Search for Erzion nuclear catalysis chains from cosmic ray Erzions stopping in organic scintillator

International Nuclear Information System (INIS)

Bazhutov, Yu.N.; Pletnikov, E.V.

2006-01-01

In the framework of Erzion model, charged cosmic ray Erzions stopping in organic substance begin to create Erzion nuclear catalysis chains with frequency of ∼ 100 MHz during ∼ 10-100 ms. Using an organic substance (plastic) scintillator we can observe long and flat (10-100 ms) pulses of large amplitude (∼100 MeV). No elementary particle can imitate such pulses. It is expected that such pulses in a plastic scintillator with mass of 100 kg will appear at the sea level every week. Such pulses can be observed every day with the Spectrometric Scintillation Super-Telescope (SSTIS) built at IZMIRAN for cosmic rays monitoring. (authors)

Pressure vessel failure at high internal pressure

International Nuclear Information System (INIS)

Laemmer, H.; Ritter, B.

1995-01-01

A RPV failure due to plastic instability was investigated using the ABAQUS finite element code together with a material model of thermal plasticity for large deformations. Not only rotational symmetric temperature distributions were studied, but also 'hot spots'. Calculations show that merely by the depletion of strength of the material - even at internal wall temperatures well below the melting point of the fuel elements of about 2000/2400 C - the critical internal pressure can decrease to values smaller than the operational pressure of 16 Mpa. (orig.)

A gamma-ray discriminating neutron scintillator

International Nuclear Information System (INIS)

Eschbach, P.A.; Miller, S.D.; Cole, M.C.

1994-01-01

A neutron scintillator has been developed at Pacific Northwest Laboratory which responds directly to as little as 10 mrem/hour dose equivalent rate fast neutron fields. The scintillator is composed of CaF 2 :Eu or of NaI grains within a silicone rubber or polystyrene matrix, respectively. Neutrons colliding with the plastic matrix provide knockon protons, which in turn deposit energy within the grains of phosphor to produce pulses of light. Neutron interactions are discriminated from gamma-ray events on the basis of pulse height. Unlike NE-213 liquid scintillators, this solid scintillator requires no pulseshape discrimination and therefore requires less hardware. Neutron events are anywhere from two to three times larger than the gamma-ray exposures are compared to 0.7 MeV gamma-ray exposures. The CaF 2 :Eu/silicone rubber scintillator is nearly optically transparent, and can be made into a very sizable detector (4 cm x 1.5 cm) without degrading pulse height. This CaF 2 :Eu scintillator has been observed to have an absolute efficiency of 0.1% when exposed to 5-MeV accelerator-generated neutrons (where the absolute efficiency is the ratio of observed neutron events divided by the number of fast neutrons striking the detector)

Primary 4{pi}{beta}-{gamma} coincidence system for standardization of radionuclides by means of plastic scintillators; Sistema primario por coincidencias 4{pi}{beta}-{gamma} para a padronizacao de radionuclideos empregando cintiladores plasticos

Energy Technology Data Exchange (ETDEWEB)

Baccarelli, Aida Maria

2003-07-01

The present work describes a 4{pi}({alpha},{beta})-{gamma} coincidence system for absolute measurement of radionuclide activity using a plastic scintillator in 4{pi} geometry for charged particles detection and a Nal (Tl) crystal for gamma-ray detection. Several shapes and dimensions of the plastic scintillator have been tried in order to obtain the best system configuration. Radionuclides which decay by alpha emission, {beta}{sup -}, {beta}{sup +} and electron capture have been standardized. The results showed excellent agreement with other conventional primary system which makes use of a 4{pi} proportional counter for X-ray and charged particle detection. The system developed in the present work have some advantages when compared with the conventional systems, namely; it does not need metal coating on the films used as radioactive source holders. When compared to liquid scintillators, is showed the advantage of not needing to be kept in dark for more than 24 h to allow phosphorescence decay of ambient light. Therefore it can be set to count immediately after the sources are placed inside of it. (author)

The development of a high-resolution scintillating fiber tracker with silicon photomultiplier readout

International Nuclear Information System (INIS)

Roper Yearwood, Gregorio

2013-01-01

In this work I present the design and test results for a novel, modular tracking detector from scintillating fibers which are read out by silicon photomultiplier (SiPM) arrays. The detector modules consist of 0.25 mm thin scintillating fibers which are closely packed in five-layer ribbons. Two ribbons are fixed to both sides of a carbon-fiber composite structure. Custom made SiPM arrays with a photo-detection efficiency of about 50% read out the fibers. Several 860 mm long and 32 mm wide tracker modules were tested in a secondary 12 GeV/c beam at the PS facilities, CERN in November of 2009. During this test a spatial resolution better than 0.05 mm at an average light yield of about 20 photons for a minimum ionizing particle was determined. This work details the characterization of scintillating fibers and silicon photomultipliers of different make and model. It gives an overview of the production of scintillating fiber modules. The behavior of detector modules during the test-beam is analyzed in detail and different options for the front-end electronics are compared. Furthermore, the implementation of the proposed tracking detector from scintillating fibers within the scope of the PERDaix experiment is discussed. The PERDaix detector is a permanent magnet spectrometer with a weight of 40 kg. It consists of 8 tracking detector layers from scintillating fibers, a time-of-flight detector from plastic scintillator bars with silicon photomultiplier readout and a transition radiation detector from an irregular fleece radiator and Xe/CO 2 filled proportional counting tubes. The PERDaix detector was launched with a helium balloon within the scope of the ''Balloon-Experiments for University Students'' (BEXUS) program from Kiruna, Sweden in November 2010. For a few hours PERDaix reached an altitude of 33 km and measured cosmic rays. In May 2011, the PERDaix detector was characterized during a test-beam at the PS-facilities at CERN. This work introduces methods for event

A lens-coupled scintillation counter in cryogenic environment

International Nuclear Information System (INIS)

Stoykov, A; Scheuermann, R; Amato, A; Bartkowiak, M; Konter, J A; Rodriguez, J; Sedlak, K

2011-01-01

In this work we present an elegant solution for a scintillation counter to be integrated into a cryogenic system. Its distinguishing feature is the absence of a continuous light guide coupling the scintillation and the photodetector parts, operating at cryogenic and room temperatures respectively. The prototype detector consists of a plastic scintillator with glued-in wavelength-shifting fiber located inside a cryostat, a Geiger-mode Avalanche Photodiode (G-APD) outside the cryostat, and a lens system guiding the scintillation light re-emitted by the fiber to the G-APD through optical windows in the cryostat shields. With a 0.8 mm diameter multiclad fiber and a 1 mm active area G-APD the coupling efficiency of the 'lens light guide' is about 50%. A reliable performance of the detector down to 3 K is demonstrated.

Scintillation Counters

Science.gov (United States)

Bell, Zane W.

Scintillators find wide use in radiation detection as the detecting medium for gamma/X-rays, and charged and neutral particles. Since the first notice in 1895 by Roentgen of the production of light by X-rays on a barium platinocyanide screen, and Thomas Edison's work over the following 2 years resulting in the discovery of calcium tungstate as a superior fluoroscopy screen, much research and experimentation have been undertaken to discover and elucidate the properties of new scintillators. Scintillators with high density and high atomic number are prized for the detection of gamma rays above 1 MeV; lower atomic number, lower-density materials find use for detecting beta particles and heavy charged particles; hydrogenous scintillators find use in fast-neutron detection; and boron-, lithium-, and gadolinium-containing scintillators are used for slow-neutron detection. This chapter provides the practitioner with an overview of the general characteristics of scintillators, including the variation of probability of interaction with density and atomic number, the characteristics of the light pulse, a list and characteristics of commonly available scintillators and their approximate cost, and recommendations regarding the choice of material for a few specific applications. This chapter does not pretend to present an exhaustive list of scintillators and applications.

Plastic scintillator with effective pulse shape discrimination for neutron and gamma detection

Science.gov (United States)

Zaitseva, Natalia P.; Carman, M Leslie; Cherepy, Nerine; Glenn, Andrew M.; Hamel, Sebastien; Payne, Stephen A.; Rupert, Benjamin L.

2016-04-12

In one embodiment, a scintillator material includes a polymer matrix; and a primary dye in the polymer matrix, the primary dye being a fluorescent dye, the primary dye being present in an amount of 5 wt % or more; wherein the scintillator material exhibits an optical response signature for neutrons that is different than an optical response signature for gamma rays. In another embodiment, a scintillator material includes a polymer matrix; and a primary dye in the polymer matrix, the primary dye being a fluorescent dye, the primary dye being present in an amount greater than 10 wt %.

Ionosphere Scintillation at Low and High Latitudes (Modelling vs Measurement)

Science.gov (United States)

Béniguel, Yannick

2016-04-01

This paper will address the problem of scintillations characteristics, focusing on the parameters of interest for a navigation system. Those parameters are the probabilities of occurrence of simultaneous fading, the bubbles surface at IPP level, the cycle slips and the fades duration statistics. The scintillation characteristics obtained at low and high latitudes will be compared. These results correspond to the data analysis performed after the ESA Monitor ionosphere measurement campaign [1], [2]. A second aspect of the presentation will be the modelling aspect. It has been observed that the phase scintillation dominates at high latitudes while the intensity scintillation dominates at low latitudes. The way it can be reproduced and implemented in a propagation model (e.g. GISM model [3]) will be presented. Comparisons of measurements with results obtained by modelling will be presented on some typical scenarios. References [1] R. Prieto Cerdeira, Y. Beniguel, "The MONITOR project: architecture, data and products", Ionospheric Effects Symposium, Alexandria (Va), May 2011 [2] Y. Béniguel, R Orus-Perez , R. Prieto-Cerdeira , S. Schlueter , S. Scortan, A. Grosu "MONITOR 2: ionospheric monitoring network in support to SBAS and other GNSS and scientific purposes", IES Conference, Alexandria (Va), May 2015-05-22 [3] Y. Béniguel, P. Hamel, "A Global Ionosphere Scintillation Propagation Model for Equatorial Regions", Journal of Space Weather Space Climate, 1, (2011), doi: 10.1051/swsc/2011004

Sci-Sat AM: Radiation Dosimetry and Practical Therapy Solutions - 10: Towards LET detection: A study on the effects of scintillator doping

Energy Technology Data Exchange (ETDEWEB)

Nusrat, Humza; Pang, Geordi; Ahmad, Syed; Keller, Brian; Sarfehnia, Arman [Ryerson University, Sunnybrook Health Sciences Centre (Canada)

2016-08-15

Purpose: In radiotherapy, the amount of radiation delivered is determined by optimizing the amount of absorbed dose to the tumor. Dose does not always correlate well with the actual biological effects of radiation. This work seeks to validate the LET-dependence of doped plastic scintillators for use in a radiation beam quality (LET) detector. Methods: The LET spectrum ([Φ]) can be resolved knowing the measured signals of uniquely LET-dependent detectors, [S], and the response of each LET-dependent detector to specific LETs ([R]), through the relation [Φ]=[S][R]{sup −1}. Plastic scintillator response is intrinsically LET dependent and can be varied via doping. Initial prototype consists of plastic scintillator and glass taper coupled to an optical fiber; components are housed in black acrylic, reducing effect of ambient light. In order to determine [R], the light response matrix, GEANT4.10.1 Monte Carlo (MC) was used. To validate MC, measurements were done using high energy electrons (9,12,15MeV) and orthovoltage x-rays (100,250kV); scintillator signal was normalized to dose measured simultaneously. Results: Stopping power was varied by changing particle type/energy; measurements indicated that as stopping power increased from 1.9 to 6.6MeV/cm, detector response increased by 263% (+/−29.2%) for 5%Pb-doped scintillator (155% in MC); 52% (+/−7.8%) increase observed when undoped scintillator was used (49% in MC). 5%Pb-doped discrepancy (100kV x-rays) is being investigated. Conclusions: This work validates that doping effects LET/energy response of scintillators; an effect that can be utilized for construction of an LET detector.

Dosimetry in clinical static magnetic fields using plastic scintillation detectors

DEFF Research Database (Denmark)

Stefanowicz, S.; Latzel, H.; Lindvold, Lars René

2013-01-01

. In conclusion, we found some deviations up to 7% of the supposed signal. Although the scintillators are of much denser material, we measured the same behavior in signal as in (Meijsing et al., 2009) for a Farmer ionization chamber or as in (Raaijmakers et al., 2007) for films described which indicates radiation......-vivo dosimetry in radiation treatments and diagnostics and could be, being all-optical, promising candidates for this application. To study the basic feasibility of using PSDs with organic scintillators in magnetic fields, we measured the response of these dosimeters in presence of magnetic fields up to 1 T...

The mechanism of coking pressure generation II: Effect of high volatile matter coking coal, semi-anthracite and coke breeze on coking pressure and contraction

Energy Technology Data Exchange (ETDEWEB)

Merrick Mahoney; Seiji Nomura; Koichi Fukuda; Kenji Kato; Anthony Le Bas; David R. Jenkins; Sid McGuire [BHP Billiton Technology, Shortland, NSW (Australia)

2010-07-15

One of the most important aspects of the cokemaking process is to control and limit the coking pressure since excessive coking pressure can lead to operational problems and oven wall damage. Following on from a previous paper on plastic layer permeability we have studied the effect of contraction of semi-coke on coking pressure and the effect of organic additives on contraction. A link between contraction (or simulated contraction) outside the plastic layer and coking pressure was demonstrated. The interaction between this contraction, local bulk density around the plastic layer and the dependence of the permeability of the plastic layer on bulk density was discussed as possible mechanisms for the generation of coking pressure. The effect of blending either a high volatile matter coal or one of two semi-anthracites with low volatile matter, high coking pressure coals on the coking pressure of the binary blends has been explained using this mechanism. 25 refs., 10 figs., 4 tabs.

Design of new polymers to improve radiation stability of plastic scintillators

International Nuclear Information System (INIS)

Barashkov, N.; Korotkikh, N.; Novikova, T.; Markley, F.; Pla-Dalmau, A.; Foster, G.; Rivard, M.

1993-11-01

Diffusion enhancers have been used to increase the radiation stability of scintillators. There is a danger that such additions will also allow the scintillation dyes to diffuse out of the matrix. Covalent bonding of the dyes into the matrix would eliminate any luminophore migration. We have demonstrated that dyes with vinyl and divinyl groups can be successfully bonded into a styrene matrix. Both primary and secondary luminophores have been bonded into the matrix and in several cases they have been compared with similar luminophores without the vinyl groups in otherwise identical compositions. In general the bonding does not greatly affect either the radiation stability of the composition or its light output, but is therefore proven to be an acceptable method of preventing luminophore migration. Scintillators with a base of aromatic or alicyclic epoxy resins have also been made with bonded luminophores. In these compositions the bonding is accomplished by using luminophores with one or two amine groups or epoxy groups. When using the amines, they are first prereacted with the epoxy resin and the modified epoxy is then cured with hexahydrophthalic anhydride or trimethoxyboroxine. The emission and absorption spectra of many of these reactive luminophores are given, along with the light outputs and radiation stability of the resulting scintilators

Design of new polymers to improve radiation stability of plastic scintillators

Energy Technology Data Exchange (ETDEWEB)

Barashkov, N.; Korotkikh, N.; Novikova, T. [Karpov Inst. of Physical Chemistry (Russian Federation); Markley, F.; Pla-Dalmau, A.; Foster, G. [Fermi National Accelerator Lab., Batavia, IL (United States); Rivard, M. [Michigan Univ., Ann Arbor, MI (United States)

1993-11-01

Diffusion enhancers have been used to increase the radiation stability of scintillators. There is a danger that such additions will also allow the scintillation dyes to diffuse out of the matrix. Covalent bonding of the dyes into the matrix would eliminate any luminophore migration. We have demonstrated that dyes with vinyl and divinyl groups can be successfully bonded into a styrene matrix. Both primary and secondary luminophores have been bonded into the matrix and in several cases they have been compared with similar luminophores without the vinyl groups in otherwise identical compositions. In general the bonding does not greatly affect either the radiation stability of the composition or its light output, but is therefore proven to be an acceptable method of preventing luminophore migration. Scintillators with a base of aromatic or alicyclic epoxy resins have also been made with bonded luminophores. In these compositions the bonding is accomplished by using luminophores with one or two amine groups or epoxy groups. When using the amines, they are first prereacted with the epoxy resin and the modified epoxy is then cured with hexahydrophthalic anhydride or trimethoxyboroxine. The emission and absorption spectra of many of these reactive luminophores are given, along with the light outputs and radiation stability of the resulting scintilators.

High-pressure-high-temperature treatment of natural diamonds

CERN Document Server

Royen, J V

2002-01-01

The results are reported of high-pressure-high-temperature (HPHT) treatment experiments on natural diamonds of different origins and with different impurity contents. The diamonds are annealed in a temperature range up to 2000 sup o C at stabilizing pressures up to 7 GPa. The evolution is studied of different defects in the diamond crystal lattice. The influence of substitutional nitrogen atoms, plastic deformation and the combination of these is discussed. Diamonds are characterized at room and liquid nitrogen temperature using UV-visible spectrophotometry, Fourier transform infrared spectrophotometry and photoluminescence spectrometry. The economic implications of diamond HPHT treatments are discussed.

Application of large area SiPMs for the readout of a plastic scintillator based timing detector

Science.gov (United States)

Betancourt, C.; Blondel, A.; Brundler, R.; Dätwyler, A.; Favre, Y.; Gascon, D.; Gomez, S.; Korzenev, A.; Mermod, P.; Noah, E.; Serra, N.; Sgalaberna, D.; Storaci, B.

2017-11-01

In this study an array of eight 6 mm × 6 mm area SiPMs was coupled to the end of a long plastic scintillator counter which was exposed to a 2.5 GeV/c muon beam at the CERN PS. Timing characteristics of bars with dimensions 150 cm × 6 cm × 1 cm and 120 cm × 11 cm × 2.5 cm have been studied. An 8-channel SiPM anode readout ASIC (MUSIC R1) based on a novel low input impedance current conveyor has been used to read out and amplify SiPMs independently and sum the signals at the end. Prospects for applications in large-scale particle physics detectors with timing resolution below 100 ps are provided in light of the results.

Analysis of mean lifetime for capture of neutrons in boron-loaded plastic scintillators

Energy Technology Data Exchange (ETDEWEB)

Kamykowski, E.A. (Grumman Corp., Bethpage, NY (USA). Research Center)

1990-12-20

The commercial availabiltiy of boron-loaded organic scintillators has led to the development of neutron detectors that operate as ''electronically'' black, totally absorbing spectrometers. The key to the enhanced spectroscopy is the delayed capture of nearly thermalized neutrons by {sup 10}B that can occur within a few microseconds after the energy pulse from prompt proton recoils. Accurate information regarding the mean lifetime is important for correct setting of the timing logic of the detection system to obtain good neutron detection efficiency with a low chance coincidence rate. In this paper we present an analysis of the mean lifetime for neutron capture for the boron-loaded plastic BC454. Measurements of the capture time constant obtained with a 7.62 cm diameter, 10.16 cm long detector are compared with values computed with the time-dependent Monte Carlo neutron transport code MCNP. Additional analyses using MCNP examine the dependence of the mean lifetime on the boron concentration, the detector's dimensions and the incident neutron energy. (orig.).

Cerenkov counting and Cerenkov-scintillation counting with high refractive index organic liquids using a liquid scintillation counter

International Nuclear Information System (INIS)

Wiebe, L.I.; Helus, F.; Maier-Borst, W.

1978-01-01

18 F and 14 C radioactivity was measured in methyl salicylate (MS), a high refractive index hybrid Cherenkov-scintillation generating medium, using a liquid scintillation counter. At concentrations of up to 21.4%, in MS, dimethyl sulfoxide (DMSO) quenched 14 C fluorescence, and with a 10-fold excess of DMSO over MS, 18 F count rates were reduced below that for DMSO alone, probably as a result of concentration-independent self-quenching due to 'dark-complex' formation. DMSO in lower concentrations did not reduce the counting efficiency of 18 F in MS. Nitrobenzene was a concentration-dependent quencher for both 14 C and 18 F in MS. Chlorobenzene (CB) and DMSO were both found to be weak Cherenkov generators with 18 F. Counting efficiencies for 18 F in MS, CB, and DMSO were 50.3, 7.8 and 4.3% respectively in the coincidence counting mode, and 58.1, 13.0 and 6.8% in the singles mode. 14 C efficiencies were 14.4 and 22.3% for coincidence and singles respectively, and 15.3 and 42.0% using a modern counter designed for coincidence and single photon counting. The high 14 C and 18 F counting efficiency in MS are discussed with respect to excitation mechanism, on the basis of quench and channels ratios changes observed. It is proposed that MS functions as an efficient Cherenkov-scintillation generator for high-energy beta emitters such as 18 F, and as a low-efficiency scintillator for weak beta emitting radionuclides such as 14 C. (author)

Optimisation of the imaging and dosimetric characteristics of an electronic portal imaging device employing plastic scintillating fibres using Monte Carlo simulations.

Science.gov (United States)

Blake, S J; McNamara, A L; Vial, P; Holloway, L; Kuncic, Z

2014-11-21

A Monte Carlo model of a novel electronic portal imaging device (EPID) has been developed using Geant4 and its performance for imaging and dosimetry applications in radiotherapy has been characterised. The EPID geometry is based on a physical prototype under ongoing investigation and comprises an array of plastic scintillating fibres in place of the metal plate/phosphor screen in standard EPIDs. Geometrical and optical transport parameters were varied to investigate their impact on imaging and dosimetry performance. Detection efficiency was most sensitive to variations in fibre length, achieving a peak value of 36% at 50 mm using 400 keV x-rays for the lengths considered. Increases in efficiency for longer fibres were partially offset by reductions in sensitivity. Removing the extra-mural absorber surrounding individual fibres severely decreased the modulation transfer function (MTF), highlighting its importance in maximising spatial resolution. Field size response and relative dose profile simulations demonstrated a water-equivalent dose response and thus the prototype's suitability for dosimetry applications. Element-to-element mismatch between scintillating fibres and underlying photodiode pixels resulted in a reduced MTF for high spatial frequencies and quasi-periodic variations in dose profile response. This effect is eliminated when fibres are precisely matched to underlying pixels. Simulations strongly suggest that with further optimisation, this prototype EPID may be capable of simultaneous imaging and dosimetry in radiotherapy.

Optimisation of the imaging and dosimetric characteristics of an electronic portal imaging device employing plastic scintillating fibres using Monte Carlo simulations

Science.gov (United States)

Blake, S. J.; McNamara, A. L.; Vial, P.; Holloway, L.; Kuncic, Z.

2014-11-01

A Monte Carlo model of a novel electronic portal imaging device (EPID) has been developed using Geant4 and its performance for imaging and dosimetry applications in radiotherapy has been characterised. The EPID geometry is based on a physical prototype under ongoing investigation and comprises an array of plastic scintillating fibres in place of the metal plate/phosphor screen in standard EPIDs. Geometrical and optical transport parameters were varied to investigate their impact on imaging and dosimetry performance. Detection efficiency was most sensitive to variations in fibre length, achieving a peak value of 36% at 50 mm using 400 keV x-rays for the lengths considered. Increases in efficiency for longer fibres were partially offset by reductions in sensitivity. Removing the extra-mural absorber surrounding individual fibres severely decreased the modulation transfer function (MTF), highlighting its importance in maximising spatial resolution. Field size response and relative dose profile simulations demonstrated a water-equivalent dose response and thus the prototype’s suitability for dosimetry applications. Element-to-element mismatch between scintillating fibres and underlying photodiode pixels resulted in a reduced MTF for high spatial frequencies and quasi-periodic variations in dose profile response. This effect is eliminated when fibres are precisely matched to underlying pixels. Simulations strongly suggest that with further optimisation, this prototype EPID may be capable of simultaneous imaging and dosimetry in radiotherapy.

Scintillator tiles with SiPM readout for calorimetry and fast timing in SuperKEKB commissioning

Energy Technology Data Exchange (ETDEWEB)

Windel, Hendrik [Max-Planck-Institute for Physics (Germany); Collaboration: CALICE-D-Collaboration

2016-07-01

The CALICE collaboration is studying plastic scintillators coupled to silicon photomultipliers as sensors for calorimeters for future linear colliders like ILC and CLIC. Current detector concepts foresee up to ten million channels for the hadronic calorimeter. A larger number of different types of SiPMs and scintillator materials exist and their properties have to be investigated to provide best results. For these purposes a dedicated laboratory setup has been developed to provide high resolution scanning of the scintillator tiles with a radioactive source. The data acquisition of this setup as well as a fast online analysis has been implemented in LABVIEW. A modified version of this setup, together with hardware previously used for measuring timing properties of hardronic showers, will be used in the commissioning phase of the SuperKEKB accelerator. This contribution discusses results from detailed investigations of different scintillator tiles, including the study of different materials. Key performance criteria for their application in calorimetry and in background measurements with high time resolution at SuperKEKB are also presented. The CALICE collaboration is studying plastic scintillators coupled to silicon photomultipliers as sensors for calorimeters for future linear colliders like ILC and CLIC. Current detector concepts foresee up two ten million channels for the hadronic calorimeter. In the real detector several thousands of these plastic scintillators will be used. To provide comparability between each of them, investigations of homogeneity for different packaging types and scintillating materials are needed as well as different attempts in tile arrangement to take inter tile crosstalk into account. A larger number of different types of SiPMs and scintillator materials exist and their properties have to be investigated to provide best results. For these purposes a dedicated LABVIEW based setup consistent of data acquisition system (DAQ) and analysis

Scintillators

International Nuclear Information System (INIS)

Cusano, D.A.; Holub, F.F.; Prochazka, S.

1979-01-01

Scintillator bodies comprising phosphor materials and having high optical translucency with low light absorption, and methods of making the scintillator bodies, are described. Fabrication methods include (a) a hot-pressing process, (b) cold-pressing followed by sintering, (c) controlled cooling from a melt, and (d) hot-forging. The scintillator bodies that result are easily machined to desired shapes and sizes. Suitable phosphors include BaFCl:Eu, LaOBr:Tb, CsI:Tl, CaWO 4 and CdWO 4 . (U.K.)

Development of a hard x-ray focal plane compton polarimeter: a compact polarimetric configuration with scintillators and Si photomultipliers

Science.gov (United States)

Chattopadhyay, T.; Vadawale, S. V.; Goyal, S. K.; Mithun, N. P. S.; Patel, A. R.; Shukla, R.; Ladiya, T.; Shanmugam, M.; Patel, V. R.; Ubale, G. P.

2016-02-01

X-ray polarization measurement of cosmic sources provides two unique parameters namely degree and angle of polarization which can probe the emission mechanism and geometry at close vicinity of the compact objects. Specifically, the hard X-ray polarimetry is more rewarding because the sources are expected to be intrinsically highly polarized at higher energies. With the successful implementation of Hard X-ray optics in NuSTAR, it is now feasible to conceive Compton polarimeters as focal plane detectors. Such a configuration is likely to provide sensitive polarization measurements in hard X-rays with a broad energy band. We are developing a focal plane hard X-ray Compton polarimeter consisting of a plastic scintillator as active scatterer surrounded by a cylindrical array of CsI(Tl) scintillators. The scatterer is 5 mm diameter and 100 mm long plastic scintillator (BC404) viewed by normal PMT. The photons scattered by the plastic scatterer are collected by a cylindrical array of 16 CsI(Tl) scintillators (5 mm × 5 mm × 150 mm) which are read by Si Photomultiplier (SiPM). Use of the new generation SiPMs ensures the compactness of the instrument which is essential for the design of focal plane detectors. The expected sensitivity of such polarimetric configuration and complete characterization of the plastic scatterer, specially at lower energies have been discussed in [11, 13]. In this paper, we characterize the CsI(Tl) absorbers coupled to SiPM. We also present the experimental results from the fully assembled configuration of the Compton polarimeter.

Electron response of some low-Z scintillators in wide energy range

International Nuclear Information System (INIS)

Swiderski, L; Marcinkowski, R; Moszynski, M; Czarnacki, W; Szawlowski, M; Szczesniak, T; Pausch, G; Plettner, C; Roemer, K

2012-01-01

Light yield nonproportionality and the intrinsic resolution of some low atomic number scintillators were studied by means of the Wide Angle Compton Coincidence (WACC) technique. The plastic and liquid scintillator response to Compton electrons was measured in the energy range of 10 keV up to 4 MeV, whereas a CaF 2 :Eu sample was scanned from 3 keV up to 1 MeV. The nonproportionality of the CaF 2 :Eu light yield has characteristics typical for inorganic scintillators of the multivalent halides group, whereas tested organic scintillators show steeply increasing nonproportionality without saturation point. This is in contrast to the behavior of all known inorganic scintillators having their nonproportionality curves at saturation above energies between tens and several hundred keV.

Electron response of some low-Z scintillators in wide energy range

Science.gov (United States)

Swiderski, L.; Marcinkowski, R.; Moszynski, M.; Czarnacki, W.; Szawlowski, M.; Szczesniak, T.; Pausch, G.; Plettner, C.; Roemer, K.

2012-06-01

Light yield nonproportionality and the intrinsic resolution of some low atomic number scintillators were studied by means of the Wide Angle Compton Coincidence (WACC) technique. The plastic and liquid scintillator response to Compton electrons was measured in the energy range of 10 keV up to 4 MeV, whereas a CaF2:Eu sample was scanned from 3 keV up to 1 MeV. The nonproportionality of the CaF2:Eu light yield has characteristics typical for inorganic scintillators of the multivalent halides group, whereas tested organic scintillators show steeply increasing nonproportionality without saturation point. This is in contrast to the behavior of all known inorganic scintillators having their nonproportionality curves at saturation above energies between tens and several hundred keV.

Extraction of depth-dependent perturbation factors for silicon diodes using a plastic scintillation detector.

Science.gov (United States)

Lacroix, Frederic; Guillot, Mathieu; McEwen, Malcolm; Gingras, Luc; Beaulieu, Luc

2011-10-01

This work presents the experimental extraction of the perturbation factor in megavoltage electron beams for three models of silicon diodes (IBA Dosimetry, EFD and SFD, and the PTW 60012 unshielded) using a plastic scintillation detector (PSD). The authors used a single scanning PSD mounted on a high-precision scanning tank to measure depth-dose curves in 6-, 12-, and 18-MeV clinical electron beams. They also measured depth-dose curves using the IBA Dosimetry, EFD and SFD, and the PTW 60012 unshielded diodes. The authors used the depth-dose curves measured with the PSD as a perturbation-free reference to extract the perturbation factors of the diodes. The authors found that the perturbation factors for the diodes increased substantially with depth, especially for low-energy electron beams. The experimental results show the same trend as published Monte Carlo simulation results for the EFD diode; however, the perturbations measured experimentally were greater. They found that using an effective point of measurement (EPOM) placed slightly away from the source reduced the variation of perturbation factors with depth and that the optimal EPOM appears to be energy dependent. The manufacturer recommended EPOM appears to be incorrect at low electron energy (6 MeV). In addition, the perturbation factors for diodes may be greater than predicted by Monte Carlo simulations.

Extraction of depth-dependent perturbation factors for silicon diodes using a plastic scintillation detector

International Nuclear Information System (INIS)

Lacroix, Frederic; Guillot, Mathieu; McEwen, Malcolm; Gingras, Luc; Beaulieu, Luc

2011-01-01

Purpose: This work presents the experimental extraction of the perturbation factor in megavoltage electron beams for three models of silicon diodes (IBA Dosimetry, EFD and SFD, and the PTW 60012 unshielded) using a plastic scintillation detector (PSD). Methods: The authors used a single scanning PSD mounted on a high-precision scanning tank to measure depth-dose curves in 6-, 12-, and 18-MeV clinical electron beams. They also measured depth-dose curves using the IBA Dosimetry, EFD and SFD, and the PTW 60012 unshielded diodes. The authors used the depth-dose curves measured with the PSD as a perturbation-free reference to extract the perturbation factors of the diodes. Results: The authors found that the perturbation factors for the diodes increased substantially with depth, especially for low-energy electron beams. The experimental results show the same trend as published Monte Carlo simulation results for the EFD diode; however, the perturbations measured experimentally were greater. They found that using an effective point of measurement (EPOM) placed slightly away from the source reduced the variation of perturbation factors with depth and that the optimal EPOM appears to be energy dependent. Conclusions: The manufacturer recommended EPOM appears to be incorrect at low electron energy (6 MeV). In addition, the perturbation factors for diodes may be greater than predicted by Monte Carlo simulations.

SU-E-T-423: TrueBeam Small Field Dosimetry Using Commercial Plastic Scintillation and Other Stereotactic Detectors

Energy Technology Data Exchange (ETDEWEB)

Pino, R [Houston Methodist Hospital, Houston, TX (United States); Therriault-Proulx, F; Wang, X; Yang, J; Beddar, S [University of Texas MD Anderson Cancer Center, Houston, TX (United States)

2014-06-01

Purpose: To perform dose profile and output factor (OF) measurements with the Exradin W1 plastic scintillation detector (PSD) for small fields made by the high-definition multi-leaf collimator (MLC) on the TrueBeam STx system and to compare them to values measured with an IBA CC01 ionization chamber and a Sun Nuclear Edge detector diode for 6 MV photon beams. Methods: The Exradin W1 is a new small volume near-water equivalent and energy independent PSD manufactured by Standard Imaging, Inc. All measurements were performed in an IBA Blue Phantom water tank. Square MLC-shaped fields with sides ranging from 0.5 cm to 2 cm and jawshaped fields with sides ranging from 1 cm to 40 cm were measured using an SAD setup at 10 cm depth. Dose profile and percent depth dose (PDD) measurements were also taken under the same conditions for MLC fields 0.5×0.5 and 1×1 cm2 in size with jaws at 2×2cm2. The CC01 and W1 were vertically mounted. Results: OFs measured with the W1 for jaw only square fields were consistent with the ones measured with a Farmers PTW TN33013 ion chamber (1.8% maximum deviation). OF and penumbra measurement results are presented below. PDDs measured for all detectors are within 1.5% for the 0.5×0.5 cm2 and within 1% for the 1×1 cm2 MLC fields.Output factors:MLC size W1 CC01 EDGE0.5cm 0.555 0.541 0.5851.0cm 0.716 0.702 0.7331.5cm 0.779 0.761 0.7772.0cm 0.804 0.785 0.796Penumbras (mm):MLC size W1 CC01 EDGE0.5cm 2.7 2.9 2.51.0cm 3.0 3.4 2. Conclusion: OFs measured for small MLC fields were consistent with the ones measured with the other stereotactic detectors. Measured penumbras are consistent with detector size. The Exradin W1 PSD is an excellent choice for characterizing MLC-shaped small beam dosimetry used for stereotactic radiosurgery and body radiation therapy. Sam Beddar would like to disclose a NIH/NCI SBIR Phase II grant (2R44CA153824-02A1) with Standard Imaging, Title: “Water-Equivalent Plastic Scintillation Detectors for Small Field

SU-E-T-423: TrueBeam Small Field Dosimetry Using Commercial Plastic Scintillation and Other Stereotactic Detectors

International Nuclear Information System (INIS)

Pino, R; Therriault-Proulx, F; Wang, X; Yang, J; Beddar, S

2014-01-01

Purpose: To perform dose profile and output factor (OF) measurements with the Exradin W1 plastic scintillation detector (PSD) for small fields made by the high-definition multi-leaf collimator (MLC) on the TrueBeam STx system and to compare them to values measured with an IBA CC01 ionization chamber and a Sun Nuclear Edge detector diode for 6 MV photon beams. Methods: The Exradin W1 is a new small volume near-water equivalent and energy independent PSD manufactured by Standard Imaging, Inc. All measurements were performed in an IBA Blue Phantom water tank. Square MLC-shaped fields with sides ranging from 0.5 cm to 2 cm and jawshaped fields with sides ranging from 1 cm to 40 cm were measured using an SAD setup at 10 cm depth. Dose profile and percent depth dose (PDD) measurements were also taken under the same conditions for MLC fields 0.5×0.5 and 1×1 cm2 in size with jaws at 2×2cm2. The CC01 and W1 were vertically mounted. Results: OFs measured with the W1 for jaw only square fields were consistent with the ones measured with a Farmers PTW TN33013 ion chamber (1.8% maximum deviation). OF and penumbra measurement results are presented below. PDDs measured for all detectors are within 1.5% for the 0.5×0.5 cm2 and within 1% for the 1×1 cm2 MLC fields.Output factors:MLC size W1 CC01 EDGE0.5cm 0.555 0.541 0.5851.0cm 0.716 0.702 0.7331.5cm 0.779 0.761 0.7772.0cm 0.804 0.785 0.796Penumbras (mm):MLC size W1 CC01 EDGE0.5cm 2.7 2.9 2.51.0cm 3.0 3.4 2. Conclusion: OFs measured for small MLC fields were consistent with the ones measured with the other stereotactic detectors. Measured penumbras are consistent with detector size. The Exradin W1 PSD is an excellent choice for characterizing MLC-shaped small beam dosimetry used for stereotactic radiosurgery and body radiation therapy. Sam Beddar would like to disclose a NIH/NCI SBIR Phase II grant (2R44CA153824-02A1) with Standard Imaging, Title: “Water-Equivalent Plastic Scintillation Detectors for Small Field

Electrophoresis of biomass decomposition products and position sensitive detection of the separated C-14 labelled substrates by plastic scintillator measurements

International Nuclear Information System (INIS)