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Sample records for liquid scintillation perals

  1. Evaluation of a photo-electron rejecting alpha liquid scintillation (PERALS) spectrometer for the measurement of alpha-emitting radionuclides

    SciTech Connect

    Cadieux, J.R.

    1990-01-01

    Results from the evaluation of a PERALS spectrometer for alpha particle measurements by liquid scintillation counting in samples from the nuclear fuel cycle are presented. Examples of PERALS spectra of process, waste, and environmental samples containing Th, U, Pu and Am from the Savannah River Site are shown. The advantages, disadvantages, and limitations of the PERALS technique are discussed. 15 refs., 11 figs.

  2. Some applications of Photon/Electron-Rejecting Alpha Liquid Scintillation (PERALS) spectrometry to the assay of alpha emitters

    SciTech Connect

    McDowell, W.J.; Case, G.N.

    1988-01-01

    The combination of certain solvent extraction separations and a special kind of liquid scintillation detector and electronics designed for alpha spectrometry allows some highly accurate, yet simple determinations of alpha-emitting nuclides. Counting efficiency is 99.68% with backgrounds of <0.02 cpm. Energy resolution and peak position are sufficient for the identification of many nuclides. Rejection of interference from ..beta.. and ..gamma.. radiation is >99.95%. The Photon/Electron Rejecting Alpha Liquid Scintillation (PERALS) equipment is described and procedures for the separation and determination of uranium, thorium, plutonium, polonium, radium, and trivalent actinides are outlined. 25 refs., 10 figs., 1 tab.

  3. Neutron crosstalk between liquid scintillators

    SciTech Connect

    Verbeke, J. M.; Prasad, M. K.; Snyderman, N. J.

    2015-05-01

    We propose a method to quantify the fractions of neutrons scattering between liquid scintillators. Using a spontaneous fission source, this method can be utilized to quickly characterize an array of liquid scintillators in terms of crosstalk. The point model theory due to Feynman is corrected to account for these multiple scatterings. Using spectral information measured by the liquid scintillators, fractions of multiple scattering can be estimated, and mass reconstruction of fissile materials under investigation can be improved. Monte Carlo simulations of mono-energetic neutron sources were performed to estimate neutron crosstalk. A californium source in an array of liquid scintillators was modeled to illustrate the improvement of the mass reconstruction.

  4. Neutron crosstalk between liquid scintillators

    NASA Astrophysics Data System (ADS)

    Verbeke, J. M.; Prasad, M. K.; Snyderman, N. J.

    2015-09-01

    A method is proposed to quantify the fractions of neutrons scattering between liquid scintillators. Using a spontaneous fission source, this method can be utilized to quickly characterize an array of liquid scintillators in terms of crosstalk. The point model theory due to Feynman is corrected to account for these multiple scatterings. Using spectral information measured by the liquid scintillators, fractions of multiple scattering can be estimated, and mass reconstruction of fissile materials under investigation can be improved. Monte Carlo simulations of mono-energetic neutron sources were performed to estimate neutron crosstalk. A californium source in an array of liquid scintillators was modeled to illustrate the improvement of the mass reconstruction.

  5. Liquid scintillator tiles for calorimetry

    NASA Astrophysics Data System (ADS)

    Amouzegar, M.; Belloni, A.; Bilki, B.; Calderon, J.; De Barbaro, P.; Eno, S. C.; Hatakeyama, K.; Hirschauer, J.; Jeng, G. Y.; Pastika, N. J.; Pedro, K.; Rumerio, Paolo; Samuel, J.; Sharp, E.; Shin, Y. H.; Tiras, E.; Vishnevskiy, D.; Wetzel, J.; Yang, Z.; Yao, Y.; Youn, S. W.

    2016-11-01

    Future experiments in high energy and nuclear physics may require large, inexpensive calorimeters that can continue to operate after receiving doses of 50 Mrad or more. The light output of liquid scintillators suffers little degradation under irradiation. However, many challenges exist before liquids can be used in sampling calorimetry, especially regarding developing a packaging that has sufficient efficiency and uniformity of light collection, as well as suitable mechanical properties. We present the results of a study of a scintillator tile based on the EJ-309 liquid scintillator using cosmic rays and test beam on the light collection efficiency and uniformity, and some preliminary results on radiation hardness.

  6. Liquid scintillator tiles for calorimetry

    SciTech Connect

    Amouzegar, M.; Belloni, A.; Bilki, B.; Calderon, J.; Barbaro, P. De; Eno, S. C.; Hatakeyama, K.; Hirschauer, J.; Jeng, G. Y.; Pastika, N. J.; Pedro, K.; Rumerio, Paolo; Samuel, J.; Sharp, E.; Shin, Y. H.; Tiras, E.; Vishnevskiy, D.; Wetzel, J.; Yang, Z.; Yao, Y.; Youn, S. W.

    2016-11-28

    Future experiments in high energy and nuclear physics may require large, inexpensive calorimeters that can continue to operate after receiving doses of 50 Mrad or more. Also, the light output of liquid scintillators suffers little degradation under irradiation. However, many challenges exist before liquids can be used in sampling calorimetry, especially regarding developing a packaging that has sufficient efficiency and uniformity of light collection, as well as suitable mechanical properties. We present the results of a study of a scintillator tile based on the EJ-309 liquid scintillator using cosmic rays and test beam on the light collection efficiency and uniformity, and some preliminary results on radiation hardness.

  7. Neutron crosstalk between liquid scintillators

    DOE PAGES

    Verbeke, J. M.; Prasad, M. K.; Snyderman, N. J.

    2015-05-01

    We propose a method to quantify the fractions of neutrons scattering between liquid scintillators. Using a spontaneous fission source, this method can be utilized to quickly characterize an array of liquid scintillators in terms of crosstalk. The point model theory due to Feynman is corrected to account for these multiple scatterings. Using spectral information measured by the liquid scintillators, fractions of multiple scattering can be estimated, and mass reconstruction of fissile materials under investigation can be improved. Monte Carlo simulations of mono-energetic neutron sources were performed to estimate neutron crosstalk. A californium source in an array of liquid scintillators wasmore » modeled to illustrate the improvement of the mass reconstruction.« less

  8. Nanophosphor composite scintillator with a liquid matrix

    DOEpatents

    McKigney, Edward Allen; Burrell, Anthony Keiran; Bennett, Bryan L.; Cooke, David Wayne; Ott, Kevin Curtis; Bacrania, Minesh Kantilal; Del Sesto, Rico Emilio; Gilbertson, Robert David; Muenchausen, Ross Edward; McCleskey, Thomas Mark

    2010-03-16

    An improved nanophosphor scintillator liquid comprises nanophosphor particles in a liquid matrix. The nanophosphor particles are optionally surface modified with an organic ligand. The surface modified nanophosphor particle is essentially surface charge neutral, thereby preventing agglomeration of the nanophosphor particles during dispersion in a liquid scintillator matrix. The improved nanophosphor scintillator liquid may be used in any conventional liquid scintillator application, including in a radiation detector.

  9. Liquid scintillator tiles for calorimetry

    DOE PAGES

    Amouzegar, M.; Belloni, A.; Bilki, B.; ...

    2016-11-28

    Future experiments in high energy and nuclear physics may require large, inexpensive calorimeters that can continue to operate after receiving doses of 50 Mrad or more. Also, the light output of liquid scintillators suffers little degradation under irradiation. However, many challenges exist before liquids can be used in sampling calorimetry, especially regarding developing a packaging that has sufficient efficiency and uniformity of light collection, as well as suitable mechanical properties. We present the results of a study of a scintillator tile based on the EJ-309 liquid scintillator using cosmic rays and test beam on the light collection efficiency and uniformity,more » and some preliminary results on radiation hardness.« less

  10. Radiopure metal-loaded liquid scintillator

    SciTech Connect

    Rosero, Richard; Yeh, Minfang

    2015-08-17

    Metal-loaded liquid scintillator plays a key role in particle and nuclear physics experiments. The applications of metal ions in various neutrino experiments and the purification methods for different scintillator components are discussed in this paper.

  11. Radiopure Metal-Loaded Liquid Scintillator

    SciTech Connect

    Rosero, Richard; Yeh, Minfang

    2015-03-18

    Metal-loaded liquid scintillator plays a key role in particle and nuclear physics experiments. The applications of metal ions in various neutrino experiments and the purification methods for different scintillator components are discussed in this paper.

  12. Detecting scintillations in liquid helium

    NASA Astrophysics Data System (ADS)

    Huffman, P. R.; McKinsey, D. N.

    2013-09-01

    We review our work in developing a tetraphenyl butadiene (TPB)-based detection system for a measurement of the neutron lifetime using magnetically confined ultracold neutrons (UCN). As part of the development of the detection system for this experiment, we studied the scintillation properties of liquid helium itself, characterized the fluorescent efficiencies of different fluors, and built and tested three detector geometries. We provide an overview of the results from these studies as well as references for additional information.

  13. Measurement of radiation damage of water-based liquid scintillator and liquid scintillator

    DOE PAGES

    Bignell, L. J.; Diwan, M. V.; Hans, S.; ...

    2015-10-19

    Liquid scintillating phantoms have been proposed as a means to perform real-time 3D dosimetry for proton therapy treatment plan verification. We have studied what effect radiation damage to the scintillator will have upon this application. We have performed measurements of the degradation of the light yield and optical attenuation length of liquid scintillator and water-based liquid scintillator after irradiation by 201 MeV proton beams that deposited doses of approximately 52 Gy, 300 Gy, and 800 Gy in the scintillator. Liquid scintillator and water-based liquid scintillator (composed of 5% scintillating phase) exhibit light yield reductions of 1.74 ± 0.55 % andmore » 1.31 ± 0.59 % after ≈ 800 Gy of proton dose, respectively. Some increased optical attenuation was observed in the irradiated samples, the measured reduction to the light yield is also due to damage to the scintillation light production. Based on our results and conservative estimates of the expected dose in a clinical context, a scintillating phantom used for proton therapy treatment plan verification would exhibit a systematic light yield reduction of approximately 0.1% after a year of operation.« less

  14. Measurement of radiation damage of water-based liquid scintillator and liquid scintillator

    SciTech Connect

    Bignell, L. J.; Diwan, M. V.; Hans, S.; Jaffe, D. E.; Rosero, R.; Vigdor, S.; Viren, B.; Worcester, E.; Yeh, M.; Zhang, C.

    2015-10-19

    Liquid scintillating phantoms have been proposed as a means to perform real-time 3D dosimetry for proton therapy treatment plan verification. We have studied what effect radiation damage to the scintillator will have upon this application. We have performed measurements of the degradation of the light yield and optical attenuation length of liquid scintillator and water-based liquid scintillator after irradiation by 201 MeV proton beams that deposited doses of approximately 52 Gy, 300 Gy, and 800 Gy in the scintillator. Liquid scintillator and water-based liquid scintillator (composed of 5% scintillating phase) exhibit light yield reductions of 1.74 ± 0.55 % and 1.31 ± 0.59 % after ≈ 800 Gy of proton dose, respectively. Some increased optical attenuation was observed in the irradiated samples, the measured reduction to the light yield is also due to damage to the scintillation light production. Based on our results and conservative estimates of the expected dose in a clinical context, a scintillating phantom used for proton therapy treatment plan verification would exhibit a systematic light yield reduction of approximately 0.1% after a year of operation.

  15. Towards 14C-free liquid scintillator

    NASA Astrophysics Data System (ADS)

    Enqvist, T.; Barabanov, I. R.; Bezrukov, L. B.; Gangapshev, A. M.; Gavrilyuk, Y. M.; Grishina, V. Yu; Gurentsov, V. I.; Hissa, J.; Joutsenvaara, J.; Kazalov, V. V.; Krokhaleva, S.; Kutuniva, J.; Kuusiniemi, P.; Kuzminov, V. V.; Kurlovich, A. S.; Loo, K.; Lubsandorzhiev, B. K.; Lubsandorzhiev, S.; Morgalyuk, V. P.; Novikova, G. Y.; Pshukov, A. M.; Sinev, V. V.; lupecki, M. S.; Trzaska, W. H.; Umerov, Sh I.; Veresnikova, A. V.; Virkajärvi, A.; Yanovich, Y. A.; Zavarzina, V. P.

    2017-09-01

    A series of measurements has been started where the 14C concentration is determined from several liquid scintillator samples. A dedicated setup has been designed and constructed with the aim of measuring concentrations smaller than 10‑18. Measurements take place in two underground laboratories: in the Baksan Neutrino Observatory, Russia, and in the new Callio Lab in the Pyhäsalmi mine, Finland. Low-energy neutrino detection with a liquid scintillator requires that the intrinsic 14C concentration in the liquid is extremely low. In the Borexino CTF detector the concentration of 2 × 10‑18 has been achieved being the lowest value ever measured. In principle, the older the oil or gas source that the liquid scintillator is derived from and the deeper it situates, the smaller the 14C concentration is supposed to be. This, however, is not generally the case and the concentration is probably due to the U and Th content of the local environment.

  16. Liquid scintillators for optical fiber applications

    SciTech Connect

    Franks, L.A.; Lutz, S.S.

    1982-11-16

    A multicomponent liquid scintillator solution for use as a radiation-to-light converter in conjunction with a fiber optic transmission system. The scintillator includes a quantity of 1, 2 , 4, 5, 3H, 6H, 1 OH, tetrahydro-8-trifluoromethyl (1) benzopyrano (9, 9a, 1-gh) quinolizin-10-one (Coumarin) as a solute in a fluor solvent such as benzyl alcohol or pseudocumene. The use of bibuq as an additional or primary solute is also disclosed.

  17. Liquid scintillators for optical fiber applications

    DOEpatents

    Franks, Larry A.; Lutz, Stephen S.

    1982-01-01

    A multicomponent liquid scintillator solution for use as a radiation-to-light converter in conjunction with a fiber optic transmission system. The scintillator includes a quantity of 1, 2, 4, 5, 3H, 6H, 1 OH, tetrahydro-8-trifluoromethyl (1) benzopyrano (9, 9a, 1-gh) quinolizin-10-one (Coumarin) as a solute in a fluor solvent such as benzyl alcohol or pseudo-cumene. The use of BIBUQ as an additional or primary solute is also disclosed.

  18. Ternary liquid scintillator for optical fiber applications

    DOEpatents

    Franks, Larry A.; Lutz, Stephen S.

    1982-01-01

    A multicomponent liquid scintillator solution for use as a radiation-to-light converter in conjunction with a fiber optic transmission system. The scintillator includes a quantity of 5-amino-9-diethylaminobenz (a) phenoxazonium nitrate (Nile Blue Nitrate) as a solute in a fluor solvent such as benzyl alcohol. The use of PPD as an additional solute is also disclosed. The system is controllable by addition of a suitable quenching agent, such as phenol.

  19. Temporally Gated Liquid Scintillator Neutron Detectors

    NASA Astrophysics Data System (ADS)

    Morrison, John T.; Frische, Kyle D.; Roquemore, W. Melvyn

    2014-10-01

    Laser based neutron sources are of interest for non-destructive testing of materials and detection of sensitive materials. These sources typically also generate large numbers of secondary x-rays and gammas which can saturate Photo Multiplier Tubes (PMT's) measuring scintillating time of flight detectors if there is not sufficient time for them to recover before the arrival of the neutron signal. Improving the response time of scintillating of medium allows for closer placement of the detectors and improved sensitivity. Liquid scintillators have been employed to reduce the decay time of the scintillating medium and temporal gating of the PMT's prevents saturation of the PMT's by the preceding gamma flash. Detector design and results of the detector calibration will be presented. The work was supported by an NRC Fellowship AFRL RO # 13.30.02.B7486.

  20. Quality study of the purified liquid scintillator

    NASA Astrophysics Data System (ADS)

    Konno, Y.; Nakajima, K.; Kibe, Y.

    2008-07-01

    We have been distilling the KamLAND liquid scintillator (LS) for the low energy solar neutrino observation. The distillation removes radioactive impurities from LS efficiently. We developed two types of high sensitivity radon detectors to monitor 222Rn contamination which causes a primary background source 210Pb. Their required sensitivity is several mBq/m3. The features and the measurement results of these detectors are presented. We also report the study of liquid scintillator properties after the distillation: attenuation length, light output and PPO density.

  1. Development of new Polysiloxane Based Liquid Scintillators

    SciTech Connect

    Dalla Palma, M.; Quaranta, A.; Gramegna, F.; Marchi, T.; Cinausero, M.; Carturan, S.; Collazuol, G.; Checchia, C.; Degerlier, M.

    2015-07-01

    In the last decade, attention toward neutron detection has been growing in the scientific community, driven by new requirements in different fields of application ranging from homeland security to medical and material analysis, from research physics, to nuclear energy production. So far neutron detection, with particular attention to fast neutrons, has been mainly based on organic liquid scintillators, owing to their good efficiency and pulse shape discrimination (PSD) capability. Most of these liquids have however some main drawbacks given by toxicity, flammability, volatility and sensitivity to dissolved oxygen that limits the duration and the quality of their performances with worse handiness and increased costs. Phenyl-substituted polysiloxanes could address most of these issues, being characterized by low toxicity, low volatility and low flammability. Their optical properties can be tailored by changing the phenyl distribution and concentration thus allowing to increase the solubility of organic dyes, to modify the fluorescence spectra and to vary the refractive index of the medium. Furthermore, polysiloxanes have been recently exploited for the production of plastic scintillators with very good chemical and thermal stability and very good radiation hardness and the development of polysiloxane liquid scintillators could allow to combine these interesting properties with the supremacy of liquid scintillators as regarding PSD over plastics. For these reasons, the properties of several phenyl-substituted polysiloxane with different phenyl amounts and different viscosities have been investigated, with particular attention to the scintillation response and the pulse shape discrimination capability, and the results of the investigation are reported in this work. More in details, the scintillation light yield towards gamma rays ({sup 60}Co and {sup 137}Cs) of several polysiloxane liquids has been analyzed and compared with the light yield of a commercial non

  2. Near-infrared scintillation of liquid argon

    SciTech Connect

    Alexander, T.; Escobar, C. O.; Lippincott, W. H.; Rubinov, P.

    2016-03-03

    Since the 1970s it has been known that noble gases scintillate in the near infrared (NIR) region of the spectrum (0.7 $\\mu$m < $\\lambda$; < 1.5$\\mu$m). More controversial has been the question of the NIR light yield for condensed noble gases. We first present the motivation for using the NIR scintillation in liquid argon detectors, then briefly review early as well as more recent efforts and finally show encouraging preliminary results of a test performed at Fermilab.

  3. Light propagation and fluorescence quantum yields in liquid scintillators

    NASA Astrophysics Data System (ADS)

    Buck, C.; Gramlich, B.; Wagner, S.

    2015-09-01

    For the simulation of the scintillation and Cherenkov light propagation in large liquid scintillator detectors a detailed knowledge about the absorption and emission spectra of the scintillator molecules is mandatory. Furthermore reemission probabilities and quantum yields of the scintillator components influence the light propagation inside the liquid. Absorption and emission properties are presented for liquid scintillators using 2,5-Diphenyloxazole (PPO) and 4-bis-(2-Methylstyryl)benzene (bis-MSB) as primary and secondary wavelength shifter. New measurements of the quantum yields for various aromatic molecules are shown.

  4. New liquid scintillators for fiber-optic applications

    SciTech Connect

    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.

  5. Liquid Scintillation Detectors for High Energy Neutrinos

    SciTech Connect

    Smith, Stefanie N.; Learned, John G.

    2010-03-30

    Large open volume (not segmented) liquid scintillation detectors have been generally dedicated to low energy neutrino measurements, in the MeV energy region. We describe the potential employment of large detectors (>1 kiloton) for studies of higher energy neutrino interactions, such as cosmic rays and long-baseline experiments. When considering the physics potential of new large instruments the possibility of doing useful measurements with higher energy neutrino interactions has been overlooked. Here we take into account Fermat's principle, which states that the first light to reach each PMT will follow the shortest path between that PMT and the point of origin. We describe the geometry of this process, and the resulting wavefront, which we are calling the 'Fermat surface', and discuss methods of using this surface to extract directional track information and particle identification. This capability may be demonstrated in the new long-baseline neutrino beam from Jaeri accelerator to the KamLAND detector in Japan. Other exciting applications include the use of Hanohano as a movable long-baseline detector in this same beam, and LENA in Europe for future long-baseline neutrino beams from CERN. Also, this methodology opens up the question as to whether a large liquid scintillator detector should be given consideration for use in a future long-baseline experiment from Fermilab to the DUSEL underground laboratory at Homestake.

  6. Purification of KamLAND-Zen liquid scintillator

    SciTech Connect

    Ikeda, Haruo

    2013-08-08

    KamLAND-Zen is neutrino-less double-beta decay search experiment using enriched 300 kg of {sup 136}Xe dissolved in pure liquid scintillator. This report is purification work of liquid scintillator for KamLAND-Zen experiment before installation in the inner-balloon and background rejection processes after installation.

  7. Liquid Scintillator Production for the NOvA Experiment

    DOE PAGES

    Mufson, S.; Baugh, B.; Bower, C.; ...

    2015-04-15

    The NOvA collaboration blended and delivered 8.8 kt (2.72M gal) of liquid scintillator as the active detector medium to its near and far detectors. The composition of this scintillator was specifically developed to satisfy NOvA's performance requirements. A rigorous set of quality control procedures was put in place to verify that the incoming components and the blended scintillator met these requirements. The scintillator was blended commercially in Hammond, IN. The scintillator was shipped to the NOvA detectors using dedicated stainless steel tanker trailers cleaned to food grade.

  8. Liquid scintillator production for the NOvA experiment

    NASA Astrophysics Data System (ADS)

    Mufson, S.; Baugh, B.; Bower, C.; Coan, T. E.; Cooper, J.; Corwin, L.; Karty, J. A.; Mason, P.; Messier, M. D.; Pla-Dalmau, A.; Proudfoot, M.

    2015-11-01

    The NOvA collaboration blended and delivered 8.8 kt (2.72M gal) of liquid scintillator as the active detector medium to its near and far detectors. The composition of this scintillator was specifically developed to satisfy NOvA's performance requirements. A rigorous set of quality control procedures was put in place to verify that the incoming components and the blended scintillator met these requirements. The scintillator was blended commercially in Hammond, IN. The scintillator was shipped to the NOvA detectors using dedicated stainless steel tanker trailers cleaned to food grade.

  9. 11C Background in Liquid Scintillator Detectors

    NASA Astrophysics Data System (ADS)

    Pocar, Andrea

    2005-09-01

    Cosmogenic 11C produced in muon showers is one of the main backgrounds for the detection of pep and CNO solar neutrinos in underground organic liquid scintillator detectors. Experimental data available for the effective cross section for 11C by muons indicate that 11C is in fact the dominant background for the observation of such neutrinos. 11C decays are expected to total a rate 2.5 (20) times higher than the combined rate of pep and CNO neutrinos in Borexino (KamLAND) in the energy window preferred for the pep measurement, between 0.8 and 1.3 MeV. Background from 11C in organic liquid scintillator detectors can be reduced if a neutron is emitted when the 11C nuclide is created. 11C decays can be tagged on a one-by-one basis using a three-fold coincidence with the parent muon track and the subsequent neutron capture on protons. The efficiency of such background reduction critically relies on the emission of a free neutron associated with 11C production. In order to verify the hypothesis, first suggested by Deutsch, that a neutron is in fact always emitted when 11C is produced, we perform a detailed ab initio calculation of the production of cosmogenic 11C, taking into consideration all relevant production channels. Results of the calculation are compared with the effective cross sections measured by target experiments in muon beams. "Bilnd" channels without a neutron in the final state account for only about 5% of 11C production modes. An estimation of the effectiveness of the one-by-one tagging of 11C events, in light of such "blind" channels is performed for KamLAND, Borexino, and a possible scintillator experiment at SNOLab. Both KamLAND and Borexino can significantly improve their pep and CNO solar neutrino signal and could perform a 3% mesurement of the pep solar neutrino flux in five years. At SNOLab depths the muon flux is low enough that 11C background would be much smaller than the pep and CNO neutrino signal and hence negligible.

  10. Measurement of ortho-positronium properties in liquid scintillators

    SciTech Connect

    Perasso, S.; Franco, D.; Tonazzo, A.; Consolati, G.; Hans, S.; Yeh, M.; Jollet, C.; Meregaglia, A.

    2013-08-08

    Pulse shape discrimination in liquid scintillator detectors is a well-established technique for the discrimination of heavy particles from light particles. Nonetheless, it is not efficient in the separation of electrons and positrons, as they give rise to indistinguishable scintillator responses. This inefficiency can be overtaken through the exploitation of the formation of ortho-Positronium (o-Ps), which alters the time profile of light pulses induced by positrons. We characterized the o-Ps properties in the most commonly used liquid scintillators, i.e. PC, PXE, LAB, OIL and PC + PPO. In addition, we studied the effects of scintillator doping on the o-Ps properties for dopants currently used in neutrino experiments, Gd and Nd. Further measurements for Li-loaded and Tl-loaded liquid scintillators are foreseen. We found that the o-Ps properties are suitable for enhancing the electron-positron discrimination.

  11. Measurement of ortho-positronium properties in liquid scintillators

    NASA Astrophysics Data System (ADS)

    Perasso, S.; Consolati, G.; Franco, D.; Hans, S.; Jollet, C.; Meregaglia, A.; Tonazzo, A.; Yeh, M.

    2013-08-01

    Pulse shape discrimination in liquid scintillator detectors is a well-established technique for the discrimination of heavy particles from light particles. Nonetheless, it is not efficient in the separation of electrons and positrons, as they give rise to indistinguishable scintillator responses. This inefficiency can be overtaken through the exploitation of the formation of ortho-Positronium (o-Ps), which alters the time profile of light pulses induced by positrons. We characterized the o-Ps properties in the most commonly used liquid scintillators, i.e. PC, PXE, LAB, OIL and PC + PPO. In addition, we studied the effects of scintillator doping on the o-Ps properties for dopants currently used in neutrino experiments, Gd and Nd. Further measurements for Li-loaded and Tl-loaded liquid scintillators are foreseen. We found that the o-Ps properties are suitable for enhancing the electron-positron discrimination.

  12. Alpha counting and spectrometry using liquid scintillation methods

    SciTech Connect

    McDowell, W J

    1986-01-01

    The material in this report is intended to be a practical introduction and guide to the use of liquid scintillation for alpha counting and spectrometry. Other works devoted to the development of the theory of liquid scintillation exist and a minimum of such material is repeated here. Much remains to be learned and many improvements remain to be made in the use of liquid scintillation for alpha counting and spectrometry. It is hoped that this modest work will encourage others to continue development in the field.

  13. Plasmonic light yield enhancement of a liquid scintillator

    SciTech Connect

    Bignell, Lindsey J.; Jackson, Timothy W.; Mume, Eskender; Lee, George P.

    2013-05-27

    We demonstrate modifications to the light yield properties of an organic liquid scintillator due to the localization of the tertiary fluorophore component to the surface of Ag-core silica-shell nanoparticles. We attribute this enhancement to the near-field interaction of Ag nanoparticle plasmons with these fluor molecules. The scintillation light yield enhancement is shown to be equal to the fluorescence enhancement within measurement uncertainties. With a suitable choice of plasmon energy and scintillation fluor, this effect may be used to engineer scintillators with enhanced light yields for radiation detection applications.

  14. Liquid xenon scintillators for imaging of positron emitters.

    PubMed

    Lavoie, L

    The current understanding of xenon scintillation physics is summarized and keyed to the use of xenon as a gamma-ray detector in medical radioisotope imaging systems. Liquid xenon has a short scintillation pulse (approximately 10(8) sec) and high gamma-ray absorption and scintillation efficiencies. The fast pulse may facilitate imaging in vivo distributions of hot positron sources and allow recovery of additional spatial information by time-of-flight techniques. We begin by describing our own study of the feasibility of making a practical positron scanning system, and consider the problems of scintillation decay time, linearity, efficiency, purity, and electricfield amplifcation. The prospects for a practical instrument are considered.

  15. Plasmonic light yield enhancement of a liquid scintillator

    NASA Astrophysics Data System (ADS)

    Bignell, Lindsey J.; Mume, Eskender; Jackson, Timothy W.; Lee, George P.

    2013-05-01

    We demonstrate modifications to the light yield properties of an organic liquid scintillator due to the localization of the tertiary fluorophore component to the surface of Ag-core silica-shell nanoparticles. We attribute this enhancement to the near-field interaction of Ag nanoparticle plasmons with these fluor molecules. The scintillation light yield enhancement is shown to be equal to the fluorescence enhancement within measurement uncertainties. With a suitable choice of plasmon energy and scintillation fluor, this effect may be used to engineer scintillators with enhanced light yields for radiation detection applications.

  16. Rayleigh scattering of linear alkylbenzene in large liquid scintillator detectors

    SciTech Connect

    Zhou, Xiang Zhang, Zhenyu; Liu, Qian; Zheng, Yangheng; Wurm, Michael; Zhang, Qingmin; Ding, Yayun; Zhou, Li; Cao, Jun; Wang, Yifang

    2015-07-15

    Rayleigh scattering poses an intrinsic limit for the transparency of organic liquid scintillators. This work focuses on the Rayleigh scattering length of linear alkylbenzene (LAB), which will be used as the solvent of the liquid scintillator in the central detector of the Jiangmen Underground Neutrino Observatory. We investigate the anisotropy of the Rayleigh scattering in LAB, showing that the resulting Rayleigh scattering length will be significantly shorter than reported before. Given the same overall light attenuation, this will result in a more efficient transmission of photons through the scintillator, increasing the amount of light collected by the photosensors and thereby the energy resolution of the detector.

  17. Rayleigh scattering of linear alkylbenzene in large liquid scintillator detectors.

    PubMed

    Zhou, Xiang; Liu, Qian; Wurm, Michael; Zhang, Qingmin; Ding, Yayun; Zhang, Zhenyu; Zheng, Yangheng; Zhou, Li; Cao, Jun; Wang, Yifang

    2015-07-01

    Rayleigh scattering poses an intrinsic limit for the transparency of organic liquid scintillators. This work focuses on the Rayleigh scattering length of linear alkylbenzene (LAB), which will be used as the solvent of the liquid scintillator in the central detector of the Jiangmen Underground Neutrino Observatory. We investigate the anisotropy of the Rayleigh scattering in LAB, showing that the resulting Rayleigh scattering length will be significantly shorter than reported before. Given the same overall light attenuation, this will result in a more efficient transmission of photons through the scintillator, increasing the amount of light collected by the photosensors and thereby the energy resolution of the detector.

  18. A large area liquid scintillation multiphoton detector

    NASA Astrophysics Data System (ADS)

    Bharadwaj, V. K.; Cain, M. P.; Caldwell, D. O.; Denby, B. H.; Eisner, A. M.; Joshi, U. P.; Kennett, R. G.; Lu, A.; Morrison, R. J.; Pfost, D. R.; Stuber, H. R.; Summers, D. J.; Yellin, S. J.; Appel, J. A.

    1985-01-01

    A 60 layer lead-liquid scintillator shower detector, which we call the SLIC, has been used for multiphoton detection in the Fermilab tagged photon spectrometer. The detector has an unimpeded active area which is 2.44 m by 4.88 m and is segmented, by means of teflon coated channels, into 3.17 cm wide strips. The 60 layers in depth are broken into three directions of alternating readouts so that three position coordinates are determined for each shower. At present the readouts are made by 334 photomultiplier tubes coupled to BBQ doped wavelength shifter bars which integrate the entire depth of the detector. It is relatively straightforward to increase the number of readouts to include longitudinal segmentation and to increase the segmentation of the outer region which are at present read out two strips to a readout. The energy and position resolutions of isolated showers are about {12%}/{√E} and 3 mm., respectively. The SLIC has been used to study the K-π+π0 decay of the D 0 [1], as well as for electron and muon identification in ψ → e +e - and ψ → μ+μ- plus π0 identification in γp → ψχ [8].

  19. Characterizing Scintillation and Cherenkov Light in Water-Based Liquid Scintillators

    NASA Astrophysics Data System (ADS)

    Land, Benjamin; Caravaca, Javier; Descamps, Freija; Orebi Gann, Gabriel

    2016-09-01

    The recent development of Water-based Liquid Scintillator (WbLS) has made it possible to produce scintillating materials with highly tunable light yields and excellent optical clarity. This allows for a straightforward combination of the directional properties of Cherenkov light with the greater energy resolution afforded by the typically brighter scintillation light which lends itself well to a broad program of neutrino physics. Here we explore the light yields and time profiles of WbLS materials in development for Theia (formerly ASDC) as measured in CheSS: our bench-top Cherenkov and scintillation separation R&D project at Berkeley Lab. This work was supported by the Laboratory Directed Research and Development Program of Lawrence Berkeley National Laboratory under U.S. Department of Energy Contract No. DE-AC02-05CH11231.

  20. Water-based scintillators for large-scale liquid calorimetry

    SciTech Connect

    Winn, D.R.; Raftery, D.

    1985-02-01

    We have investigated primary and secondary solvent intermediates in search of a recipe to create a bulk liquid scintillator with water as the bulk solvent and common fluors as the solutes. As we are not concerned with energy resolution below 1 MeV in large-scale experiments, light-output at the 10% level of high-quality organic solvent based scintillators is acceptable. We have found encouraging performance from industrial surfactants as primary solvents for PPO and POPOP. This technique may allow economical and environmentally safe bulk scintillator for kiloton-sized high energy calorimetry.

  1. On the scintillation efficiency of carborane-loaded liquid scintillators for thermal neutron detection

    NASA Astrophysics Data System (ADS)

    Chang, Zheng; Okoye, Nkemakonam C.; Urffer, Matthew J.; Green, Alexander D.; Childs, Kyle E.; Miller, Laurence F.

    2015-01-01

    The scintillation efficiency in response to thermal neutrons was studied by loading different concentrations of carborane (0-8.5 wt%) and naphthalene (0 and 100 g/L) in five liquid organic scintillators. The sample was characterized in Pb and Cd shields under the irradiation of the thermal neutrons from a 252Cf source. A method was developed to extract the net neutron response from the pulse-height spectra. It was found that the order of scintillation efficiencies for both γ-rays and thermal neutrons is as follows: diisopropylnaphthalene>toluene (concentrated solutes)>toluene~pseudocumene~m-xylene. The quench constants, obtained by fitting the Stern-Volmer model to the plots of light output versus carborane concentration, are in the range of 0.35-1.4 M-1 for all the scintillators. The Birks factors, estimated using the specific energy loss profiles of the incident particles, are in the range of 9.3-14 mg cm-2 MeV-1 for all the samples. The light outputs are in the range of 63-86 keV electron equivalents (keVee) in response to thermal neutrons. Loading naphthalene generally promotes the scintillation efficiency of the scintillator with a benzene derivative solvent. Among all the scintillators tested, the diisopropylnaphthalene-based scintillator shows the highest scintillation efficiency, lowest Birks factor, and smallest quench constants. These properties are primarily attributed to the double fused benzene-ring structure of the solvent, which is more efficient to populate to the excited singlet state under ionizing radiation and to transfer the excitation energy to the fluorescent solutes.

  2. Ternary liquid scintillator for optical-fiber applications

    SciTech Connect

    Franks, L.A.; Lutz, S.S.

    1981-06-01

    A multicomponent liquid scintillator solution for use as a radiation-to-light converter in conjunction with a fiber optic transmission system. The scintillator includes a quantity of 5-amino-9-diethylaminobenz (a) phenoxazonium nitrate (Nile Blue Nitrate) as a solute in a fluor solvent such as benzyl alcohol. The use of PPD as an additional solute is also disclosed. The system is controllable by addition of a suitable quenching agent, such as phenol.

  3. Fluorescence decay-time constants in organic liquid scintillators.

    PubMed

    Marrodán Undagoitia, T; von Feilitzsch, F; Oberauer, L; Potzel, W; Ulrich, A; Winter, J; Wurm, M

    2009-04-01

    The fluorescence decay-time constants have been measured for several scintillator mixtures based on phenyl-o-xylylethane (PXE) and linear alkylbenzene (LAB) solvents. The resulting values are of relevance for the physics performance of the proposed large-volume liquid scintillator detector Low Energy Neutrino Astronomy (LENA). In particular, the impact of the measured values to the search for proton decay via p-->K(+)nu is evaluated in this work.

  4. Fluorescence decay-time constants in organic liquid scintillators

    SciTech Connect

    Marrodan Undagoitia, T.; Feilitzsch, F. von; Oberauer, L.; Potzel, W.; Ulrich, A.; Winter, J.; Wurm, M.

    2009-04-15

    The fluorescence decay-time constants have been measured for several scintillator mixtures based on phenyl-o-xylylethane (PXE) and linear alkylbenzene (LAB) solvents. The resulting values are of relevance for the physics performance of the proposed large-volume liquid scintillator detector Low Energy Neutrino Astronomy (LENA). In particular, the impact of the measured values to the search for proton decay via p{yields}K{sup +}{nu} is evaluated in this work.

  5. Purification of large liquid scintillators for Borexino

    SciTech Connect

    Benziger, J.B.; Calaprice, F.P.; Vogelaar, R.B.

    1993-10-01

    Distillation extraction and crystallization have been used on scintillator mixtures for solar neutrino physics to remove cosmo- genically produced impurities ({sup 7}Be) and naturally occurring impurities ({sup 238}U, {sup 232}Th, and {sup 40}K), and to improve the optical transmission. Distillation was effective at removing {sup 7}Be and other impurities from aromatic solvents (p-xylene and pseudocumene) used as scintillator solvents. Distillation also provided the greatest improvement in the optical clarity of the solvents. Commercially available fluors (PPO and PMP) have high levels of potassium, far in excess of those tolerable for Borexino. Extraction techniques have been found to be effective at removing radioactive impurities, particularly potassium, from the fluors. An overall strategy for on-line purification of the scintillator for Borexino will be presented.

  6. Development of a liquid scintillator neutron multiplicity counter (LSMC)

    NASA Astrophysics Data System (ADS)

    Frame, Katherine; Clay, Willam; Elmont, Tim; Esch, Ernst; Karpius, Peter; MacArthur, Duncan; McKigney, Edward; Santi, Peter; Smith, Morag; Thron, Jonathan; Williams, Richard

    2007-08-01

    A new neutron multiplicity counter is being developed that utilizes the fast response of liquid scintillator detectors. The ability to detect fast (vs. moderated) fission neutrons makes possible a coincidence gate of the order of tens of nanoseconds (vs. tens of microseconds). A neutron counter with such a narrow gate will be virtually insensitive to accidental coincidences, making it possible to measure items with a high single neutron background to greater accuracy in less time. This includes impure Pu items with high (α, n) rates as well as items of low-mass HEU where a strong active interrogation source is needed. Liquid scintillator detectors also allow for energy discrimination between interrogation source neutrons and fission neutrons, allowing for even greater assay sensitivity. Designing and building a liquid scintillator multiplicity counter (LSMC) requires a symbiotic effort of simulation and experiment to optimize performance and mitigate hardware costs in the final product. We present preliminary Monte-Carlo studies using the GEANT toolkit.

  7. Measurement of ortho-positronium properties in liquid scintillators

    NASA Astrophysics Data System (ADS)

    Perasso, S.; Consolati, G.; Franco, D.; Jollet, C.; Meregaglia, A.; Tonazzo, A.; Yeh, M.

    2014-03-01

    Pulse shape discrimination is a well-established technique for background rejection in liquid scintillator detectors. It is particularly effective in separating heavy particles from light particles, but not in distinguishing electrons from positrons. This inefficiency can be overtaken by exploiting the formation of ortho-positronium (o-Ps), which alters the time profile of light pulses induced by positrons. We characterized the o-Ps properties in the most commonly used liquid scintillators, i.e. PC, PXE, LAB, OIL and PC + PPO. In addition, we studied the effects of scintillator doping on the o-Ps properties for dopants used in neutrino-less double beta decay experiments (Nd and Te) and in anti-neutrino and neutron detection (Gd and Li respectively). We found that the o-Ps properties are similar in all the tested scintillators, with a lifetime around 3 ns and a formation probability of about 50%. This result indicates that an o-Ps-enhanced pulse shape discrimination can be applied in liquid scintillator detectors for neutrino and anti-neutrino detection and for neutrino-less double beta decay search.

  8. Calculations and measurements of the scintillator-to-water stopping power ratio of liquid scintillators for use in proton radiotherapy

    PubMed Central

    Ingram, W. Scott; Robertson, Daniel; Beddar, Sam

    2015-01-01

    Liquid scintillators are a promising detector for high-resolution three-dimensional proton therapy dosimetry. Because the scintillator comprises both the active volume of the detector and the phantom material, an ideal scintillator will exhibit water equivalence in its radiological properties. One of the most fundamental of these is the scintillator’s stopping power. The objective of this study was to compare calculations and measurements of scintillator-to-water stopping power ratios to evaluate the suitability of the liquid scintillators BC-531 and OptiPhase HiSafe 3 for proton dosimetry. We also measured the relative scintillation output of the two scintillators. Both calculations and measurements show that the linear stopping power of OptiPhase is significantly closer to water than that of BC-531. BC-531 has a somewhat higher scintillation output. OptiPhase can be mixed with water at high concentrations, which further improves its scintillator-to-water stopping power ratio. However, this causes the solution to become cloudy, which has a negative impact on the scintillation output and spatial resolution of the detector. OptiPhase is preferred over BC-531 for proton dosimetry because its density and scintillator-to-water stopping power ratio are more water equivalent. PMID:25705066

  9. Direct determination of lead-210 by liquid-scintillation counting

    NASA Technical Reports Server (NTRS)

    Fairman, W. D.; Sedlet, J.

    1969-01-01

    Soft betas, the internal conversion electrons, and unconverted gamma rays from lead-210 are efficiently detected in a liquid scintillation counting system with efficiency of 97 percent. The counter is interfaced with a multichannel pulse height analyzer. The spectra obtained is stored on paper tape and plotted on an x-y plotter.

  10. Measurement of Scintillation and Ionization Yield and Scintillation Pulse Shape from Nuclear Recoils in Liquid Argon

    SciTech Connect

    Cao, H.

    2015-05-26

    We have measured the scintillation and ionization yield of recoiling nuclei in liquid argon as a function of applied electric field by exposing a dual-phase liquid argon time projection chamber (LAr-TPC) to a low energy pulsed narrow band neutron beam produced at the Notre Dame Institute for Structure and Nuclear Astrophysics. Liquid scintillation counters were arranged to detect and identify neutrons scattered in the TPC and to select the energy of the recoiling nuclei. We also report measurements of the scintillation yields for nuclear recoils with energies from 10.3 to 57.3 keV and for median applied electric fields from 0 to 970 V/cm. For the ionization yields, we report measurements from 16.9 to 57.3 keV and for electric fields from 96.4 to 486 V/cm. Furthermore, we report the observation of an anticorrelation between scintillation and ionization from nuclear recoils, which is similar to the anticorrelation between scintillation and ionization from electron recoils. Assuming that the energy loss partitions into excitons and ion pairs from 83mKr internal conversion electrons is comparable to that from 207Bi conversion electrons, we obtained the numbers of excitons (Nex) and ion pairs (Ni) and their ratio (Nex/Ni) produced by nuclear recoils from 16.9 to 57.3 keV. Motivated by arguments suggesting direction sensitivity in LAr-TPC signals due to columnar recombination, a comparison of the light and charge yield of recoils parallel and perpendicular to the applied electric field is presented for the first time.

  11. Measurement of scintillation and ionization yield and scintillation pulse shape from nuclear recoils in liquid argon

    NASA Astrophysics Data System (ADS)

    Cao, H.; Alexander, T.; Aprahamian, A.; Avetisyan, R.; Back, H. O.; Cocco, A. G.; Dejongh, F.; Fiorillo, G.; Galbiati, C.; Grandi, L.; Guardincerri, Y.; Kendziora, C.; Lippincott, W. H.; Love, C.; Lyons, S.; Manenti, L.; Martoff, C. J.; Meng, Y.; Montanari, D.; Mosteiro, P.; Olvitt, D.; Pordes, S.; Qian, H.; Rossi, B.; Saldanha, R.; Sangiorgio, S.; Siegl, K.; Strauss, S. Y.; Tan, W.; Tatarowicz, J.; Walker, S.; Wang, H.; Watson, A. W.; Westerdale, S.; Yoo, J.; Scene Collaboration

    2015-05-01

    We have measured the scintillation and ionization yield of recoiling nuclei in liquid argon as a function of applied electric field by exposing a dual-phase liquid argon time projection chamber (LAr-TPC) to a low energy pulsed narrow band neutron beam produced at the Notre Dame Institute for Structure and Nuclear Astrophysics. Liquid scintillation counters were arranged to detect and identify neutrons scattered in the TPC and to select the energy of the recoiling nuclei. We report measurements of the scintillation yields for nuclear recoils with energies from 10.3 to 57.3 keV and for median applied electric fields from 0 to 970 V /cm . For the ionization yields, we report measurements from 16.9 to 57.3 keV and for electric fields from 96.4 to 486 V /cm . We also report the observation of an anticorrelation between scintillation and ionization from nuclear recoils, which is similar to the anticorrelation between scintillation and ionization from electron recoils. Assuming that the energy loss partitions into excitons and ion pairs from Krm83 internal conversion electrons is comparable to that from 207Bi conversion electrons, we obtained the numbers of excitons (Nex) and ion pairs (Ni) and their ratio (Nex/Ni ) produced by nuclear recoils from 16.9 to 57.3 keV. Motivated by arguments suggesting direction sensitivity in LAr-TPC signals due to columnar recombination, a comparison of the light and charge yield of recoils parallel and perpendicular to the applied electric field is presented for the first time.

  12. Measurement of Scintillation and Ionization Yield and Scintillation Pulse Shape from Nuclear Recoils in Liquid Argon

    DOE PAGES

    Cao, H.

    2015-05-26

    We have measured the scintillation and ionization yield of recoiling nuclei in liquid argon as a function of applied electric field by exposing a dual-phase liquid argon time projection chamber (LAr-TPC) to a low energy pulsed narrow band neutron beam produced at the Notre Dame Institute for Structure and Nuclear Astrophysics. Liquid scintillation counters were arranged to detect and identify neutrons scattered in the TPC and to select the energy of the recoiling nuclei. We also report measurements of the scintillation yields for nuclear recoils with energies from 10.3 to 57.3 keV and for median applied electric fields from 0more » to 970 V/cm. For the ionization yields, we report measurements from 16.9 to 57.3 keV and for electric fields from 96.4 to 486 V/cm. Furthermore, we report the observation of an anticorrelation between scintillation and ionization from nuclear recoils, which is similar to the anticorrelation between scintillation and ionization from electron recoils. Assuming that the energy loss partitions into excitons and ion pairs from 83mKr internal conversion electrons is comparable to that from 207Bi conversion electrons, we obtained the numbers of excitons (Nex) and ion pairs (Ni) and their ratio (Nex/Ni) produced by nuclear recoils from 16.9 to 57.3 keV. Motivated by arguments suggesting direction sensitivity in LAr-TPC signals due to columnar recombination, a comparison of the light and charge yield of recoils parallel and perpendicular to the applied electric field is presented for the first time.« less

  13. Measurement of scintillation and ionization yield and scintillation pulse shape from nuclear recoils in liquid argon

    SciTech Connect

    Cao, H.; Alexander, T.; Aprahamian, A.; Avetisyan, R.; Back, H. O.; Cocco, A. G.; DeJongh, F.; Fiorillo, G.; Galbiati, C.; Grandi, L.; Guardincerri, Y.; Kendziora, C.; Lippincott, W. H.; Love, C.; Lyons, S.; Manenti, L.; Martoff, C. J.; Meng, Y.; Montanari, D.; Mosteiro, P.; Olvitt, D.; Pordes, S.; Qian, H.; Rossi, B.; Saldanha, R.; Sangiorgio, S.; Siegl, K.; Strauss, S. Y.; Tan, W.; Tatarowicz, J.; Walker, S.; Wang, H.; Watson, A. W.; Westerdale, S.; Yoo, J.

    2015-05-01

    We have measured the scintillation and ionization yield of recoiling nuclei in liquid argon as a function of applied electric field by exposing a dual-phase liquid argon time projection chamber (LAr-TPC) to a low energy pulsed narrow band neutron beam produced at the Notre Dame Institute for Structure and Nuclear Astrophysics. Liquid scintillation counters were arranged to detect and identify neutrons scattered in the TPC and to select the energy of the recoiling nuclei. We report measurements of the scintillation yields for nuclear recoils with energies from 10.3 to 57.3 keV and for median applied electric fields from 0 to 970 V / cm . For the ionization yields, we report measurements from 16.9 to 57.3 keV and for electric fields from 96.4 to 486 V / cm . We also report the observation of an anticorrelation between scintillation and ionization from nuclear recoils, which is similar to the anticorrelation between scintillation and ionization from electron recoils. Assuming that the energy loss partitions into excitons and ion pairs from 83 m Kr internal conversion electrons is comparable to that from 207 Bi conversion electrons, we obtained the numbers of excitons ( N ex ) and ion pairs ( N i ) and their ratio ( N ex / N i ) produced by nuclear recoils from 16.9 to 57.3 keV. Motivated by arguments suggesting direction sensitivity in LAr-TPC signals due to columnar recombination, a comparison of the light and charge yield of recoils parallel and perpendicular to the applied electric field is presented for the first time.

  14. Liquid scintillation composition for low volume biological specimens

    SciTech Connect

    Mallik, A.; Edelstein, H.

    1984-04-17

    A liquid scintillation cocktail especially suitable for low volume biological specimens comprising an aromatic liquid, preferably pseudocumene, for capturing energy from radiation, at least one fluor, preferably PPO and Bis-MSB, and a mixture of anionic and nonionic surfactants. The cocktails are prepared by treating with a cation exchange resin to clarify and with a solid buffer to raise the temperature at which cloudiness develops upon heating.

  15. A capability for monitoring effluent tritium with liquid scintillation/robotics

    SciTech Connect

    Winn, W.G. )

    1993-01-01

    Strong interest persists in developing real-time tritium effluent monitoring. At the Savannah River site, this interest was intensified following a release from a K reactor heat exchanger in December 1991. Follow-up research and development resulted in adapting a flow-through tritium monitor based on scintillation beads and developing a similar system that mixes liquid scintillant into the sample stream. The bead system has the advantage of consuming little scintillant material, while the liquid scintillation method affords much better sensitivity. This study examines a method based on liquid scintillation and robotics, which can provide sensitivity and scintillant requirements that are intermediate to the foregoing.

  16. Comparing the response of PSD-capable plastic scintillator to standard liquid scintillator

    NASA Astrophysics Data System (ADS)

    Woolf, Richard S.; Hutcheson, Anthony L.; Gwon, Chul; Phlips, Bernard F.; Wulf, Eric A.

    2015-06-01

    This work discusses a test campaign to characterize the response of the recently developed plastic scintillator with pulse shape discrimination (PSD) capabilities (EJ-299-33). PSD is a property exhibited by certain types of scintillating material in which incident stimuli (fast neutrons or γ rays) can be separated by exploiting differences in the scintillation light pulse tail. Detector geometries used were: a 10 cm×10 cm×10 cm cube and a 10-cm diameter×10-cm long cylinder. EJ-301 and EJ-309 liquid scintillators with well-known responses were also tested. The work was conducted at the University of Massachusetts Lowell Van De Graaff accelerator. The facility accelerated protons on a thin Li target to yield quasi-monoenergetic neutrons from the 7Li(p,n)7Be reaction (Q-value: -1.644 MeV). Collimated fast neutrons were obtained by placing detectors behind a neutron spectrometer. Rotating the spectrometer, and thus changing the neutron energy, allowed us to achieve 0.5-3.2 MeV neutrons in 200-300 keV steps. Data were acquired through a flash analog-to-digital converter (ADC) capable of performing digital PSD measurements. By using the PSD technique to separate the neutron events from unwanted γ background, we constructed a pulse height spectrum at each energy. Obtaining a relationship of the relative light output versus energy allowed us to construct the response function for the EJ-299-33 and liquid scintillator. The EJ-299-33 response in terms of electron equivalent energy (Ee.e.) vs. proton equivalent energy (Ep.e.), how it compared with the standard xylene-based EJ-301 (or, NE-213/BC-501 A equivalent) and EJ-309 liquid scintillator response, and how the EJ-301 and EJ-309 compared, are presented. We find that the EJ-299-33 demonstrated a lower light output by up to 40% for <1.0 MeV neutrons; and ranging between a 5-35% reduction for 2.5-3.0 MeV neutrons compared to the EJ-301/309, depending on the scintillator and geometry. Monte Carlo modeling techniques were

  17. Positronium signature in organic liquid scintillators for neutrino experiments

    SciTech Connect

    Franco, D.; Consolati, G.; Trezzi, D.

    2011-01-15

    Electron antineutrinos are commonly detected in liquid scintillator experiments via inverse {beta} decay by looking at the coincidence between the reaction products: neutrons and positrons. Prior to positron annihilation, an electron-positron pair may form an orthopositronium (o-Ps) state, with a mean lifetime of a few nanoseconds. Even if the o-Ps decay is speeded up by spin-flip or pick-off effects, it may introduce distortions in the photon emission time distribution, crucial for position reconstruction and pulse shape discrimination algorithms in antineutrino experiments. Reversing the problem, the o-Ps-induced time distortion represents a new signature for tagging antineutrinos in liquid scintillator. In this article, we report the results of measurements of the o-Ps formation probability and lifetime for the most used solvents for organic liquid scintillators in neutrino physics (pseudocumene, linear alkyl benzene, phenylxylylethane, and dodecane). We characterize also a mixture of pseudocumene +1.5 g/l of 2,5-diphenyloxazole, a fluor acting as wavelength shifter. In the second part of the article, we demonstrate that the o-Ps-induced distortion of the scintillation photon emission time distributions represent an optimal signature for tagging positrons on an event by event basis, potentially enhancing the antineutrino detection.

  18. Optical Design Considerations for Efficient Light Collection from Liquid Scintillation Counters

    SciTech Connect

    Bernacki, Bruce E.; Douglas, Matthew; Erchinger, Jennifer L.; Fuller, Erin S.; Keillor, Martin E.; Morley, Shannon M.; Mullen, Crystal A.; Orrell, John L.; Panisko, Mark E.; Warren, Glen A.; Wright, Michael E.

    2015-01-01

    Liquid scintillation counters measure charged particle-emitting radioactive isotopes and are used for environmental studies, nuclear chemistry, and life science. Alpha and beta emissions arising from the material under study interact with the scintillation cocktail to produce light. The prototypical liquid scintillation counter employs low-level photon-counting detectors to measure the arrival of the scintillation light produced as a result of the dissolved material under study interacting with the scintillation cocktail. For reliable operation the counting instrument must convey the scintillation light to the detectors efficiently and predictably. Current best practices employ the use of two or more detectors for coincidence processing to discriminate true scintillation events from background events due to instrumental effects such as photomultiplier tube dark rates, tube flashing, or other light emission not generated in the scintillation cocktail vial. In low background liquid scintillation counters additional attention is paid to shielding the scintillation cocktail from naturally occurring radioactive material (NORM) present in the laboratory and within the instruments construction materials. Low background design is generally at odds with optimal light collection. This study presents the evolution of a light collection design for liquid scintillation counting in a low background shield. The basic approach to achieve both good light collection and a low background measurement is described. The baseline signals arising from the scintillation vial are modeled and methods to efficiently collect scintillation light are presented as part of the development of a customized low-background, high sensitivity liquid scintillation counting system.

  19. SBIR Final Report. Liquid Core Optical Scintillating Fibers

    SciTech Connect

    Beetz, C.P.; Steinbeck, J.; Buerstler, R.

    2000-05-16

    This Phase I SBIR project focused on developing flexible scintillating liquid core optical fibers, with potential uses in high-energy calorimetry, tracking, preradiators, active targets or other fast detectors. Progress on the six tasks of the project is summarized. The technical developments involve three technology components: (1) highly flexible capillaries or tubes of relatively low n (index of refraction) to serve as cladding and liquid core containment; (2) scintillator (and clear) fluids of relatively high n to serve as a core-- these fluids must have a high light transmission and, for some applications, radiation hardness; (3) optical end plugs, plug insertion, and plug-cladding tube sealing technology to contain the core fluids in the tubes, and to transmit the light.

  20. Optical properties of quantum-dot-doped liquid scintillators

    NASA Astrophysics Data System (ADS)

    Aberle, C.; Li, J. J.; Weiss, S.; Winslow, L.

    2013-10-01

    Semiconductor nanoparticles (quantum dots) were studied in the context of liquid scintillator development for upcoming neutrino experiments. The unique optical and chemical properties of quantum dots are particularly promising for the use in neutrinoless double-beta decay experiments. Liquid scintillators for large scale neutrino detectors have to meet specific requirements which are reviewed, highlighting the peculiarities of quantum-dot-doping. In this paper, we report results on laboratory-scale measurements of the attenuation length and the fluorescence properties of three commercial quantum dot samples. The results include absorbance and emission stability measurements, improvement in transparency due to filtering of the quantum dot samples, precipitation tests to isolate the quantum dots from solution and energy transfer studies with quantum dots and the fluorophore PPO.

  1. Optical properties of quantum-dot-doped liquid scintillators.

    PubMed

    Aberle, C; Li, J J; Weiss, S; Winslow, L

    2013-10-14

    Semiconductor nanoparticles (quantum dots) were studied in the context of liquid scintillator development for upcoming neutrino experiments. The unique optical and chemical properties of quantum dots are particularly promising for the use in neutrinoless double-beta decay experiments. Liquid scintillators for large scale neutrino detectors have to meet specific requirements which are reviewed, highlighting the peculiarities of quantum-dot-doping. In this paper, we report results on laboratory-scale measurements of the attenuation length and the fluorescence properties of three commercial quantum dot samples. The results include absorbance and emission stability measurements, improvement in transparency due to filtering of the quantum dot samples, precipitation tests to isolate the quantum dots from solution and energy transfer studies with quantum dots and the fluorophore PPO.

  2. Optical properties of quantum-dot-doped liquid scintillators

    PubMed Central

    Aberle, C.; Li, J.J.; Weiss, S.; Winslow, L.

    2014-01-01

    Semiconductor nanoparticles (quantum dots) were studied in the context of liquid scintillator development for upcoming neutrino experiments. The unique optical and chemical properties of quantum dots are particularly promising for the use in neutrinoless double-beta decay experiments. Liquid scintillators for large scale neutrino detectors have to meet specific requirements which are reviewed, highlighting the peculiarities of quantum-dot-doping. In this paper, we report results on laboratory-scale measurements of the attenuation length and the fluorescence properties of three commercial quantum dot samples. The results include absorbance and emission stability measurements, improvement in transparency due to filtering of the quantum dot samples, precipitation tests to isolate the quantum dots from solution and energy transfer studies with quantum dots and the fluorophore PPO. PMID:25392711

  3. Organic liquid scintillation detector shape and volume impact on radiation portal monitors

    NASA Astrophysics Data System (ADS)

    Paff, Marc G.; Clarke, Shaun D.; Pozzi, Sara A.

    2016-07-01

    We have developed and tested a radiation portal monitor using organic liquid scintillation detectors. In order to optimize our system designs, neutron measurements were carried out with three organic liquid scintillation detectors of different shapes and sizes, along with a 3He radiation portal monitor (RPM) as a reference. The three liquids tested were a 7.62 cm diameter by 7.62 cm length cylindrical active volume organic liquid scintillation detector, a 12.7 cm diameter by 12.7 cm length cylindrical active volume organic liquid scintillation detector, and a 25 cm by 25 cm by 10 cm "paddle" shaped organic liquid scintillation detector. Background and Cf-252 neutron measurements were recorded to allow for a comparison of neutron intrinsic efficiencies as well as receiver operating characteristics (ROC) curves between detectors. The 12.7 cm diameter cylindrical active volume organic liquid scintillation detector exhibited the highest intrinsic neutron efficiency (54%) of all three liquid scintillators. An ROC curve analysis for a heavily moderated Cf-252 measurement showed that using the 12.7 cm diameter by 12.7 cm length cylindrical active volume Eljen EJ309 organic liquid scintillation detector would result in the fewest needed detector units in order to achieve a near 100% positive neutron alarm rate while maintaining a better than 1 in 10,000 false alarm rate on natural neutron background. A small number of organic liquid scintillation detectors could therefore be a valid alternative to 3He in some RPM applications.

  4. Radiation effects on wavelength shifting fibers used with liquid scintillators

    SciTech Connect

    Ables, E.; Armatis, P.; Bionta, R.; Britt, H.; Clamp, O.; Cochran, C.; Graham, G.; Lowry, M.; Masquelier, D.; Skulina, K.; Wuest, C.; Bolen, L.; Cremaldi, L.; Harper, S.; Moore, B.; Quinn, B.; Reidy, J.; Zhou, J.; Croft, L.; Piercey, R.; Bauer, M.L.; Bishop, B.L.; Cohn, H.O.; Gabriel, T.A.; Gordeev, A.; Kamyshkov, Yu.; Lillei, R.A.; Plasil, F.; Read, K.; Rennich, M.J.; Savin, A.; Shmakov, K.; Singeltary, B.H.; Smirnov, A.; Tarkovsky, E.; Todd, R.A.; Young, K.G.; Berridge, S.C.; Bugg, W.M.; Handler, T.; Pisharody, M.; Aziz, T.; Banerjee, S.; Chendvankar, S.R.; Ganfuli, S.N.; Malhotra, K.; Mazumdar, K.; Raghavan, R.; Shankar, K.; Sudhakar, K.; Tonwar, S.C.; Arefiev, A.; Baranov, O.; Efremenko, Yu.; Gorodkov, Yu.; Malinin, A.; Nikitin, A.; Markizov, V.; Onoprienko, D.; Rozjkov, A.; Shoumilov, E.; Shoutko, V.

    1992-06-01

    The chemical compatibility of wave length shifting fibers with several liquid scintillators has been investigated. Based on systematic characterization of the behavior of the BC-517 family, a time of life of 70{endash}450 years was estimated for the polystyrene based wave length shifting fiber in BC-517P scintillator. WLS (wavelength shifting) fibers irradiated continuously to a dose of 6.4 Mrads (at .377Mrad/hr of Co-60) were observed to decrease from 100% to 5% transmission; however, after 100 hours of annealing, the transmission increased to 90%. Geant simulations of a simplified calorimeter located behind a BaF2 electromagnetic calorimeter for the GEM detector at SSC showed that the constant term in the energy resolution will change from 1.8 to 2.9 in five years at 10{star}{star}34 luminosity for psuedorapidity eta=3.

  5. Detecting energy dependent neutron capture distributions in a liquid scintillator

    NASA Astrophysics Data System (ADS)

    Balmer, Matthew J. I.; Gamage, Kelum A. A.; Taylor, Graeme C.

    2015-03-01

    A novel technique is being developed to estimate the effective dose of a neutron field based on the distribution of neutron captures in a scintillator. Using Monte Carlo techniques, a number of monoenergetic neutron source energies and locations were modelled and their neutron capture response was recorded. Using back propagation Artificial Neural Networks (ANN) the energy and incident direction of the neutron field was predicted from the distribution of neutron captures within a 6Li-loaded liquid scintillator. Using this proposed technique, the effective dose of 252Cf, 241AmBe and 241AmLi neutron fields was estimated to within 30% for four perpendicular angles in the horizontal plane. Initial theoretical investigations show that this technique holds some promise for real-time estimation of the effective dose of a neutron field.

  6. Stability of Gd-loaded liquid scintillator for reactor neutrino detection

    NASA Astrophysics Data System (ADS)

    Katsumata, M.; Miyata, H.; Tamura, N.; Kawasaki, T.

    2011-02-01

    Gd-loaded liquid scintillators are promising tools for detection of anti-electron neutrinos, yet their stability remains a concern for neutrino experiments. This study investigated the instability of a Gd-loaded liquid scintillator and found that Gd precipitated and light yield decreased due to oxidation. The precipitation not only reduced transmission but also decreased the Gd concentration. However, when the antioxidant 2,6-di- tert-butyl-4-methylphenol (BHT) was added to the liquid scintillator, we obtained a stable liquid scintillator at room temperature.

  7. A study of liquid scintillator and fiber materials for use in a fiber calorimeter

    SciTech Connect

    Altice, P.P. Jr.

    1990-04-01

    This reports an investigation into the performance of selected scintillation oils and fiber materials to test their applicability in high energy, liquid scintillator calorimetry. Two scintillating oils, Bicron BC-517 and an oil mixed for the MACRO experiment, and two fiber materials, Teflon and GlassClad PS-252, were tested for the following properties: light yield, attenuation length and internal reflection angle. The results of these tests indicated that the scintillation oils and the fiber materials had an overall good performance with lower energies and would meet the requirements of liquid scintillator detection at SSC energies. 6 refs.

  8. N-(2-Ethylhexyl)carbazole: A New Fluorophore Highly Suitable as a Monomolecular Liquid Scintillator.

    PubMed

    Montbarbon, Eva; Sguerra, Fabien; Bertrand, Guillaume H V; Magnier, Élodie; Coulon, Romain; Pansu, Robert B; Hamel, Matthieu

    2016-08-16

    The synthesis, photophysical properties, and applications in scintillation counting of N-(2-ethylhexyl)carbazole (EHCz) are reported. This molecule displays all of the required characteristics for an efficient liquid scintillator (emission wavelength, scintillation yield), and can be used without any extra fluorophores. Thus, its scintillation properties are discussed, as well as its fast neutron/gamma discrimination. For the latter application, the material is compared with the traditional liquid scintillator BC-501 A, and other liquid fluorescent molecules classically used as scintillation solvents, such as xylene, pseudocumene (PC), linear alkylbenzenes (LAB), diisopropylnaphthalene (DIN), 1-methylnaphthalene (1-MeNapht), and 4-isopropylbiphenyl (iPrBiph). For the first time, an excimeric form of a molecule has been advantageously used in scintillation counting. A moderate discrimination between fast neutrons and gamma rays was observed in bulk EHCz, with an apparent neutron/gamma discrimination potential half of that of BC-501 A.

  9. Developing Detectors for Scintillation Light in Liquid Argon for DUNE

    SciTech Connect

    Howard, Bruce

    2016-12-22

    The Deep Underground Neutrino experiment will conduct a broad program of physics research by studying a beam of neutrinos from Fermilab, atmospheric neutrinos, neutrinos from potential supernovae, and potential nucleon decay events. In pursuit of these studies, the experiment will deploy four 10kt fiducial mass liquid argon time projection chambers underground in Lead, South Dakota. Liquid argon time projection chambers allow high-resolution tracking and energy measurements. A precise timing signal is needed to provide the necessary time stamp to localize events in the drift direction. As liquid argon is a natural scintillator, a photon detection system will be deployed to provide such a signal, especially for non-beam events. In the baseline design for the single-phase time projection chamber, the detectors are contained within the anode plane assemblies. The design of two prototypes utilizing wavelength shifters and light guides are presented, and aspects of the research and development program are discussed.

  10. Optical scattering lengths in large liquid-scintillator neutrino detectors.

    PubMed

    Wurm, M; von Feilitzsch, F; Göger-Neff, M; Hofmann, M; Lachenmaier, T; Lewke, T; Marrodán Undagoitia, T; Meindl, Q; Möllenberg, R; Oberauer, L; Potzel, W; Tippmann, M; Todor, S; Traunsteiner, C; Winter, J

    2010-05-01

    For liquid-scintillator neutrino detectors of kiloton scale, the transparency of the organic solvent is of central importance. The present paper reports on laboratory measurements of the optical scattering lengths of the organic solvents phenylxylylethane, linear alkylbenzene (LAB), and dodecane, which are under discussion for next-generation experiments such as SNO+ (Sudbury Neutrino Observatory), HanoHano, or LENA (Low Energy Neutrino Astronomy). Results comprise the wavelength range of 415-440 nm. The contributions from Rayleigh and Mie scattering as well as from absorption/re-emission processes are discussed. Based on the present results, LAB seems to be the preferred solvent for a large-volume detector.

  11. Optical scattering lengths in large liquid-scintillator neutrino detectors

    SciTech Connect

    Wurm, M.; Feilitzsch, F. von; Goeger-Neff, M.; Hofmann, M.; Lewke, T.; Meindl, Q.; Moellenberg, R.; Oberauer, L.; Potzel, W.; Tippmann, M.; Todor, S.; Winter, J.; Lachenmaier, T.; Traunsteiner, C.; Undagoitia, T. Marrodan

    2010-05-15

    For liquid-scintillator neutrino detectors of kiloton scale, the transparency of the organic solvent is of central importance. The present paper reports on laboratory measurements of the optical scattering lengths of the organic solvents phenylxylylethane, linear alkylbenzene (LAB), and dodecane, which are under discussion for next-generation experiments such as SNO+ (Sudbury Neutrino Observatory), HanoHano, or LENA (Low Energy Neutrino Astronomy). Results comprise the wavelength range of 415-440 nm. The contributions from Rayleigh and Mie scattering as well as from absorption/re-emission processes are discussed. Based on the present results, LAB seems to be the preferred solvent for a large-volume detector.

  12. Determination of Total Body Radioactivity Using Liquid Scintillation Detectors

    NASA Astrophysics Data System (ADS)

    Reines, F.; Schuch, R. L.; Cowan, C. L.; Harrison, F. B.; Anderson, E. C.; Hayes, F. N.

    IN the course of developing equipment for other problems1, we have made some measurements of the total radioactivity content of several humans and a dog, using a technique which may have other applications in biophysics. The equipment used consists of a liquid scintillation detector in the shape of a cylinder 30 in. in diameter and 30 in. high, surrounded by RCA type 5819 photomultipliers, fortyfive of which were used in these measurements. Cylindrical steel inserts, 14 in. in diameter in one case and 20 in. in diameter in another, 32 in. high and 0.015 in. thick, were placed in the tank, leaving an annular region filled with liquid scintillator (toluene-terphenyl-α-naphthyl phenyl oxazole). A lead shield 5 in. thick was placed around the assembly, leaving only the top of the insert open. The fortyfive photomultipliers were connected in parallel and their output fed through a linear amplifier to a tenchannel pulse-height analyser (see Fig. 1)…

  13. High speed liquid scintillators for optical fiber applications

    NASA Astrophysics Data System (ADS)

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

    1982-02-01

    Three liquid scintillator systems have been developed which offer the long-wavelength emission and short impulse response required for long-path, wide-bandwidth, optical fiber applications. Binary liquid systems employing the dye Coumarin 540-A are reported with impulse responses (fwhm) of 1.4 ns at 570 nm in benzyl alcohol and 350 ps at 525 nm in pseudo-cumene. Addition of 10 g/ℓ of 4,4‴ di(2-butyloctoxy-1)-p-quaterphenyl substantially improves performance of the latter system at low Coumarin 540 concentrations. A third system using the dye Nile Blue nitrate has a fwhm of less than 1 ns at 700 nm when simultaneously heated and quenched with phenol.

  14. Scintillation light from cosmic-ray muons in liquid argon

    SciTech Connect

    Whittington, Denver Wade; Mufson, S.; Howard, B.

    2016-05-01

    This paper reports the results of an experiment to directly measure the time-resolved scintillation signal from the passage of cosmic-ray muons through liquid argon. Scintillation light from these muons is of value to studies of weakly-interacting particles in neutrino experiments and dark matter searches. The experiment was carried out at the TallBo dewar facility at Fermilab using prototype light guide detectors and electronics developed for the Deep Underground Neutrino Experiment. Two models are presented for the time structure of the scintillation light, a phenomenological model and a physically-motivated model. Both models find tT = 1:52 ms for the decay time constant of the Ar 2 triplet state. These models also show that the identification of the “early” light fraction in the phenomenological model, FE 25% of the signal, with the total light from singlet decays is an underestimate. The total fraction of singlet light is FS 36%, where the increase over FE is from singlet light emitted by the wavelength shifter through processes with long decay constants. The models were further used to compute the experimental particle identification parameter Fprompt, the fraction of light coming in a short time window after the trigger compared with the light in the total recorded waveform. The models reproduce quite well the typical experimental value 0.3 found by dark matter and double b-decay experiments, which suggests this parameter provides a robust metric for discriminating electrons and muons from more heavily ionizing particles.

  15. A large liquid scintillator detector for a long baseline neutrino oscillation experiment

    NASA Astrophysics Data System (ADS)

    Border, P.; Cushman, P.; Heller, K.; Maxam, D.; Nelson, J. K.; Ruddick, K.; Rusack, R.; Schwienhorst, R.; Berg, T.; Chase, T.; Hansen, M.; Bower, C.; Hatcher, R.; Heinz, R.; Miller, L.; Mufson, S.

    2001-05-01

    We present the concept and design of a liquid scintillator detector for a long-baseline neutrino oscillation experiment. Neutrinos interact in 2.5 cm thick steel plates alternating with 2.0 cm thick planes of liquid scintillator. The scintillator is contained in multicell PVC extrusions containing individual 2 cm×3 cm cells up to 8 m long. Readout of the scintillation light is via wavelength-shifting fibers which transport light to pixellated photodetectors at one end of the cells.

  16. Optimization of screening for radioactivity in urine by liquid scintillation.

    SciTech Connect

    Shanks, Sonoya Toyoko; Reese, Robert P.; Preston, Rose T.

    2007-08-01

    Numerous events have or could have resulted in the inadvertent uptake of radionuclides by fairly large populations. Should a population receive an uptake, valuable information could be obtained by using liquid scintillation counting (LSC) techniques to quickly screen urine from a sample of the affected population. This study investigates such LSC parameters as discrimination, quench, volume, and count time to yield guidelines for analyzing urine in an emergency situation. Through analyzing variations of the volume and their relationships to the minimum detectable activity (MDA), the optimum ratio of sample size to scintillating chemical cocktail was found to be 1:3. Using this optimum volume size, the alpha MDA varied from 2100 pCi/L for a 30-second count time to 35 pCi/L for a 1000-minute count time. The typical count time used by the Sandia National Laboratories Radiation Protection Sample Diagnostics program is 30 minutes, which yields an alpha MDA of 200 pCi/L. Because MDA is inversely proportional to the square root of the count time, count time can be reduced in an emergency situation to achieve the desired MDA or response time. Note that approximately 25% of the response time is used to prepare the samples and complete the associated paperwork. It was also found that if the nuclide of interest is an unknown, pregenerated discriminator settings and efficiency calibrations can be used to produce an activity value within a factor of two, which is acceptable for a screening method.

  17. Liquid argon scintillation light studies in LArIAT

    SciTech Connect

    Kryczynski, Pawel

    2016-10-12

    The LArIAT experiment is using its Liquid Argon Time Projection Chamber (LArTPC) in the second run of data-taking at the Fermilab Test Beam Facility. The goal of the experiment is to study the response of LArTPCs to charged particles of energies relevant for planned neutrino experiments. In addition, it will help to develop and evaluate the performance of the simulation, analysis, and reconstruction software used in other LAr neutrino experiments. Particles from a tertiary beam detected by LArIAT (mainly protons, pions and muons) are identified using a set of beamline detectors, including Wire Chambers, Time of Flight counters and Cherenkov counters, as well as a simplified sampling detector used to detect muons. In its effort towards augmenting LArTPC technology for other neutrino experiments, LArIAT also takes advantage of the scintillating capabilities of LAr and is testing the possibility of using the light signal to help reconstruct calorimetric information and particle ID. In this report, we present results from these studies of the scintillation light signal to evaluate detector performance and calorimetry.

  18. Liquid argon scintillation light studies in LArIAT

    NASA Astrophysics Data System (ADS)

    Kryczynski, Pawel; LArIAT Collaboration

    2017-09-01

    The LArIAT experiment is using its Liquid Argon Time Projection Chamber (LArTPC) in the second run of data-taking at the Fermilab Test Beam Facility. The goal of the experiment is to study the response of LArTPCs to charged particles of energies relevant for planned neutrino experiments. In addition, it will help to develop and evaluate the performance of the simulation, analysis, and reconstruction software used in other LAr neutrino experiments. Particles from a tertiary beam detected by LArIAT (mainly protons, pions and muons) are identified using a set of beamline detectors, including Wire Chambers, Time of Flight counters and Cherenkov counters, as well as a simplified sampling detector used to detect muons. In its effort towards augmenting LArTPC technology for other neutrino experiments, LArIAT also takes advantage of the scintillating capabilities of LAr and is testing the possibility of using the light signal to help reconstruct calorimetric information and particle ID. In this report, we present results from these studies of the scintillation light signal to evaluate detector performance and calorimetry.

  19. Improved pulse shape discrimination in EJ-301 liquid scintillators

    NASA Astrophysics Data System (ADS)

    Lang, R. F.; Masson, D.; Pienaar, J.; Röttger, S.

    2017-06-01

    Digital pulse shape discrimination has become readily available to distinguish nuclear recoil and electronic recoil events in scintillation detectors. We evaluate digital implementations of pulse shape discrimination algorithms discussed in the literature, namely the Charge Comparison Method, Pulse-Gradient Analysis, Fourier Series and Standard Event Fitting. In addition, we present a novel algorithm based on a Laplace Transform. Instead of comparing the performance of these algorithms based on a single Figure of Merit, we evaluate them as a function of recoil energy. Specifically, using commercial EJ-301 liquid scintillators, we examined both the resulting acceptance of nuclear recoils at a given rejection level of electronic recoils, as well as the purity of the selected nuclear recoil event samples. We find that both a Standard Event fit and a Laplace Transform can be used to significantly improve the discrimination capabilities over the whole considered energy range of 0 - 800keVee . Furthermore, we show that the Charge Comparison Method performs poorly in accurately identifying nuclear recoils.

  20. A step toward CNO solar neutrino detection in liquid scintillators

    NASA Astrophysics Data System (ADS)

    Villante, F. L.; Ianni, A.; Lombardi, F.; Pagliaroli, G.; Vissani, F.

    2011-07-01

    The detection of CNO solar neutrinos in ultrapure liquid scintillator detectors is limited by the background produced by bismuth-210 nuclei that undergo β-decay to polonium-210 with a lifetime of ˜7 days. Polonium-210 nuclei are unstable and decay with a lifetime equal to ˜200 days emitting α particles that can be also detected. In this Letter, we show that the Bi-210 background can be determined by looking at the time evolution of α-decay rate of Po-210, provided that α particle detection efficiency is stable over the data acquisition period and external sources of Po-210 are negligible. A sufficient accuracy can be obtained in a relatively short time. As an example, if the initial Po-210 event rate is ˜2000 cpd/100 ton or lower, a Borexino-like detector could start discerning CNO neutrino signal from Bi-210 background in Δt˜1 yr.

  1. Optimization of Pulse Shape Discrimination of PROSPECT Liquid Scintillator Signals

    NASA Astrophysics Data System (ADS)

    Han, Ke; Prospect Collaboration

    2015-04-01

    PROSPECT, A Precision Oscillation and Spectrum Experiment, will use a segmented Li-6 doped liquid scintillator detector for precision measurement of the reactor anti-neutrino spectrum at the High Flux Isotope Reactor at Oak Ridge National Laboratory. PROSPECT also searches for very short baseline neutrino oscillation, an indication of the existence of eV-scale sterile neutrinos. Pulse shape analysis of the prompt anti-neutino signal and delayed neutron capture on Li-6 signal will greatly suppress background sources such as fast neutrons and accidental coincidence of gammas. In this talk, I will discuss different pulse shape parameters used in PROSPECT prototype detectors and multivariate optimization of event selection cuts based on those parameters.

  2. Quality assurance manual plutonium liquid scintillation methods and procedures

    SciTech Connect

    Romero, L.

    1997-01-01

    Nose swipe analysis is a very important tool for Radiation Protection personnel. Nose swipe analysis is a very fast and accurate method for (1) determining if a worker has been exposed to airborne plutonium contamination and (2) Identifying the area where there has been a possible plutonium release. Liquid scintillation analysis techniques have been effectively applied to accurately determine the plutonium alpha activity on nose swipe media. Whatman-40 paper and Q-Tips are the only two media which have been evaluated and can be used for nose swipe analysis. Presently, only Q-Tips are used by Group HSE-1 Radiation Protection Personnel. However, both swipe media will be discussed in this report.

  3. Deuterated Liquid Scintillators: A New Tool for Neutron Measurements

    SciTech Connect

    Ojaruega, M.; Becchetti, F. D.; Torres-Isea, R.; Villano, A. N.; Roberts, A.; Kolata, J. J.; Lawrence, C. C.; Pozzi, S. A.; Flaska, M.; Clarke, S. D.

    2011-12-13

    The response of large (4x6) deuterated liquid scintillators (up to 10 cm diameter by 15 cm) to neutrons in the energy range from 0.5 MeV to 20 MeV has been studied using several nuclear reactions, including d(d,n), and {sup 12}C(d,n){sup 13}N, at the University of Notre Dame FN tandem accelerator. The latter two reactions utilized 9 MeV and 16 MeV deuteron beams, including a pulsed beam that also permitted time-of-flight (ToF) measurements. Combining pulse-shape discrimination and (ToF) allows gating on specific neutron energy groups to determine the detector response to specific neutron energies. Newly-obtained and optimized pulse shape discrimination using digitized pulse analysis from these detectors will be presented in this paper. These measurements confirmed the ability of these detectors to provide useful neutron spectra without ToF.

  4. Characterization and Modeling of a Water-based Liquid Scintillator

    SciTech Connect

    L. J. Bignell; Beznosko, D.; Diwan, M. V.; Hans, S.; Jaffe, D. E.; S. Kettell; Rosero, R.; Themann, H. W.; Viren, B.; Worcester, E.; Yeh, M.; Zhang, C.

    2015-12-15

    We characterised Water-based Liquid Scintillator (WbLS) using low energy protons, UV-VIS absorbance, and fluorescence spectroscopy. We have also developed and validated a simulation model that describes the behaviour of WbLS in our detector configurations for proton beam energies of 210 MeV, 475 MeV, and 2 GeV and for two WbLS compositions. These results have enabled us to estimate the light yield and ionisation quenching of WbLS, as well as to understand the influence of the wavelength shifting of Cherenkov light on our measurements. These results are relevant to the suitability of WbLS materials for next generation intensity frontier experiments.

  5. Background characterization of an ultra-low background liquid scintillation counter

    DOE PAGES

    Erchinger, J. L.; Orrell, John L.; Aalseth, C. E.; ...

    2017-01-26

    The Ultra-Low Background Liquid Scintillation Counter developed by Pacific Northwest National Laboratory will expand the application of liquid scintillation counting by enabling lower detection limits and smaller sample volumes. By reducing the overall count rate of the background environment approximately 2 orders of magnitude below that of commercially available systems, backgrounds on the order of tens of counts per day over an energy range of ~3–3600 keV can be realized. Finally, initial test results of the ULB LSC show promising results for ultra-low background detection with liquid scintillation counting.

  6. Application of scintillating properties of liquid xenon and silicon photomultiplier technology to medical imaging

    NASA Astrophysics Data System (ADS)

    Gomez-Cadenas, J. J.; Benlloch-Rodriguez, J. M.; Ferrario, Paola

    2016-04-01

    We describe a new positron emission time-of-flight apparatus using liquid xenon. The detector is based in a liquid xenon scintillating cell. The cell shape and dimensions can be optimized depending on the intended application. In its simplest form, the liquid xenon scintillating cell is a box in which two faces are covered by silicon photomultipliers and the others by a reflecting material such as Teflon. It is a compact, homogenous and highly efficient detector which shares many of the desirable properties of monolithic crystals, with the added advantage of high yield and fast scintillation offered by liquid xenon. Our initial studies suggest that good energy and spatial resolution comparable with that achieved by lutetium oxyorthosilicate crystals can be obtained with a detector based in liquid xenon scintillating cells. In addition, the system can potentially achieve an excellent coincidence resolving time of better than 100 ps.

  7. Design optimization of liquid scintillator cosmic-ray veto detector with BBQ shifter

    SciTech Connect

    Kruse, H.W.; Egdorf, S.S.; Simmons, D.F.

    1981-10-01

    Certain design characteristics of a liquid scintillator detector for charged cosmic particles, have been studied. These include evaluation of scintillator emission spectra, absorption in various thicknesses of BBQ shifter bars and effective transmission in long lengths of BBQ acrylic. For our BBQ sample, 12.5 mm thick with semicircular shape, the shifted light was transmitted with 2.0 m absorption length.

  8. Fast range measurement of spot scanning proton beams using a volumetric liquid scintillator detector

    PubMed Central

    Hui, CheukKai; Robertson, Daniel; Alsanea, Fahed; Beddar, Sam

    2016-01-01

    Accurate confirmation and verification of the range of spot scanning proton beams is crucial for correct dose delivery. Current methods to measure proton beam range using ionization chambers are either time-consuming or result in measurements with poor spatial resolution. The large-volume liquid scintillator detector allows real-time measurements of the entire dose profile of a spot scanning proton beam. Thus, liquid scintillator detectors are an ideal tool for measuring the proton beam range for commissioning and quality assurance. However, optical artefacts may decrease the accuracy of measuring the proton beam range within the scintillator tank. The purpose of the current study was to 1) develop a geometric calibration system to accurately calculate physical distances within the liquid scintillator detector, taking into account optical artefacts; and 2) assess the accuracy, consistency, and robustness of proton beam range measurement using the liquid scintillator detector with our geometric calibration system. The range of the proton beam was measured with the calibrated liquid scintillator system and was compared to the nominal range. Measurements were made on three different days to evaluate the setup robustness from day to day, and three sets of measurements were made for each day to evaluate the consistency from delivery to delivery. All proton beam ranges measured using the liquid scintillator system were within half a millimeter of the nominal range. The delivery-to-delivery standard deviation of the range measurement was 0.04 mm, and the day-to-day standard deviation was 0.10 mm. In addition to the accuracy and robustness demonstrated by these results when our geometric calibration system was used, the liquid scintillator system allowed the range of all 94 proton beams to be measured in just two deliveries, making the liquid scintillator detector a perfect tool for range measurement of spot scanning proton beams. PMID:27274863

  9. Comparison of neutron spectra measured with three sizes of organic liquid scintillators using differentiation analysis

    NASA Technical Reports Server (NTRS)

    Shook, D. F.; Pierce, C. R.

    1972-01-01

    Proton recoil distributions were obtained by using organic liquid scintillators of different size. The measured distributions are converted to neutron spectra by differentiation analysis for comparison to the unfolded spectra of the largest scintillator. The approximations involved in the differentiation analysis are indicated to have small effects on the precision of neutron spectra measured with the smaller scintillators but introduce significant error for the largest scintillator. In the case of the smallest cylindrical scintillator, nominally 1.2 by 1.3 cm, the efficiency is shown to be insensitive to multiple scattering and to the angular distribution to the incident flux. These characteristics of the smaller scintillator make possible its use to measure scalar flux spectra within media high efficiency is not required.

  10. Liquid scintillator composition optimization for use in ultra-high energy cosmic ray detector systems

    NASA Astrophysics Data System (ADS)

    Beznosko, Dmitriy; Batyrkhanov, Ayan; Iakovlev, Alexander; Yelshibekov, Khalykbek

    2017-06-01

    The Horizon-T (HT) detector system and the currently under R&D HT-KZ detector system are designed for the detection of Extensive Air Showers (EAS) with energies above ˜1016 eV (˜1017 eV for HT-KZ). The main challenges in both detector systems are the fast time resolutions needed for studying the temporary structure of EAS, and the extremely wide dynamic range needed to study the spatial distribution of charged particles in EAS disks. In order to detect the low-density of charged particles far from the EAS axis, a large-area detector is needed. Liquid scintillator with low cost would be a possible solution for such a detector, including the recently developed safe and low-cost water-based liquid scintillators. Liquid organic scintillators give a fast and high light yield (LY) for charged particle detection. It is similar to plastic scintillator in properties but is cost effective for large volumes. With liquid scintillator, one can create detection volumes that are symmetric and yet retain high LY detection. Different wavelength shifters affect the scintillation light by changing the output spectrum into the best detection region. Results of the latest studies of the components optimization in the liquid scintillator formulae are presented.

  11. Study of absorption and re-emission processes in a ternary liquid scintillation system

    NASA Astrophysics Data System (ADS)

    Xiao, Hua-Lin; Li, Xiao-Bo; Zheng, Dong; Cao, Jun; Wen, Liang-Jian; Wang, Nai-Yan

    2010-11-01

    Liquid scintillators are widely used as the neutrino target in neutrino experiments. The absorption and emission of different components of a ternary liquid scintillator (Linear Alkyl Benzene (LAB) as the solvent, 2,5-diphenyloxazole (PPO) as the fluor and p-bis-(o-methylstyryl)-benzene (bis-MSB) as wavelength shifter) are studied. It is shown that the absorption of this liquid scintillator is dominant by LAB and PPO at wavelengths less than 349 nm, and the absorption by bis-MSB becomes prevalent at the wavelength larger than 349 nm. The fluorescence quantum yields, which are the key parameters to model the absorption and re-emission processes in large liquid scintillation detectors, are measured.

  12. A bottle crusher, built to facilitate the disposal of liquid scintillation waste.

    PubMed

    Presswell, D; Bailey, M R

    1984-01-01

    A crusher for liquid scintillation bottles, designed to dispose of 2500 bottles per week, employs a revolving drum and sump for collection of spent fluid. Air extraction maintains safe levels by removing flammable vapours.

  13. Discovery potential for supernova relic neutrinos with slow liquid scintillator detectors

    NASA Astrophysics Data System (ADS)

    Wei, Hanyu; Wang, Zhe; Chen, Shaomin

    2017-06-01

    Detection of supernova relic neutrinos could provide key support for our current understanding of stellar and cosmological evolution, and precise measurements of these neutrinos could yield novel insights into the universe. In this paper, we studied the detection potential of supernova relic neutrinos using linear alkyl benzene (LAB) as a slow liquid scintillator. The linear alkyl benzene features good separation of Cherenkov and scintillation lights, thereby providing a new route for particle identification. We further addressed key issues in current experiments, including (1) the charged current background of atmospheric neutrinos in water Cherenkov detectors and (2) the neutral current background of atmospheric neutrinos in typical liquid scintillator detectors. A kiloton-scale LAB detector at Jinping with O(10) years of data could discover supernova relic neutrinos with a sensitivity comparable to that of large-volume water Cherenkov detectors, typical liquid scintillator detectors, and liquid argon detectors.

  14. Properties of Quantum-Dot-Doped Liquid Scintillators

    NASA Astrophysics Data System (ADS)

    Coy, Christopher

    2014-03-01

    Novel scintillators based on semiconducting nanocrystals called quantum dots have unique optical and chemical properties that make them interesting for future neutrino experiments especially those searching for neutrino-less double beta decay. In this talk, we report the results of laboratory-scale measurements for three candidate quantum-dot-doped scintillators. We focus on the key properties required for large-scale neutrino experiments, which are the emission spectrum, the attenuation length and the stability. I would like to follow the talk by Andrey Elagin on directionality in scintillators and precede Athena Ierokomos' talk on light yield in scintillators.

  15. Biocomponent determination in vinegars with the help of 14C measured by liquid scintillation counting.

    PubMed

    Tudyka, Konrad; Pawlyta, Jacek

    2014-02-15

    This article presents a method of carbon extraction from vinegar used in preparation of liquid scintillation counting cocktails for measurements of low (14)C radioactivity. The presented method is relatively fast and can be used to produce liquid scintillation cocktails e.g., via benzene synthesis. In this work we present specific radiocarbon radioactivity determinations and based on them estimation of bio product content for five commercially available vinegars. All investigated vinegars are likely produced from plants in fermentation process.

  16. Double phase (liquid/gas) xenon scintillation detector for WIMPs direct search

    NASA Astrophysics Data System (ADS)

    Yamashita, M.; Doke, T.; Kikuchi, J.; Suzuki, S.

    2003-10-01

    A double phase (liquid/gas) xenon prototype detector of a 0.3 l active volume for WIMPs direct search has been constructed and tested. Proportional scintillation signals are observed by a multi-wire anode mounted in gas phase after ionization electrons drifted successfully long distance in liquid xenon. Both direct and proportional scintillation were used to discriminate electron recoil from nuclear recoil. Basic performances of the detector and the rejection efficiency of background gamma rays were demonstrated.

  17. Retrospective Determination of Radon Exposure to Glass Using Liquid Scintillation Counting

    NASA Astrophysics Data System (ADS)

    Jones, Rodger Ferguson

    A method is introduced whereby glass samples exposed to known levels of ^{222}Rn are analyzed for ^{210}Pb build-up by liquid scintillation counting. This retrospective radon detector relies on the phenomena of recoil of the decaying nuclide on emission of an alpha -particle into the substrate of the glass. Simple liquid scintillation counting is then used to measure the activity of the ^{210}Pb. The surface of the glass containing the decay products is etched with hydrofluoric acid and then added to a scintillant. The method is useful for exposures up from around 250 PCi.l ^{-1}-years giving a correlation of.97 in a controlled laboratory experiment.

  18. Characterization of a cubic EJ-309 liquid scintillator detector

    NASA Astrophysics Data System (ADS)

    Tomanin, A.; Paepen, J.; Schillebeeckx, P.; Wynants, R.; Nolte, R.; Lavietes, A.

    2014-08-01

    A cubic EJ-309 liquid scintillator of 10 cm width has been characterized for its response to γ-rays and neutrons. Response functions to γ-rays were measured with calibrated radionuclide γ-ray sources in the energy range from 400 keV to 6 MeV. Response functions for neutrons were obtained from measurements at the PTB Van de Graaff accelerator with quasi-monoenergetic neutron beams in the energy range from 500 keV to 2.7 MeV, and at the PTB cyclotron with time-of-flight (TOF) measurements in the energy range from 2.5 to 14 MeV. The light output and resolution functions for electrons and protons were derived by a least squares adjustment to experimental data using theoretical response functions determined with Monte Carlo simulations. The simulated response function for neutron was validated by results of measurements with an AmBe neutron source which was characterized for its total neutron intensity. The results indicate that the cubic EJ-309 detector is suitable for use in mixed γ-ray and neutron fields.

  19. Development of a Position Sensitive Liquid Scintillator Bar-type Detector

    NASA Astrophysics Data System (ADS)

    Atencio, Ariella; Cizewski, Jolie; Walter, David; Chipps, Kelly; Febbraro, Michael; Pain, Steven; Smith, Karl; Thornsberry, Cory

    2016-09-01

    The ability to detect neutrons is important for both nuclear reactions and beta decay. Liquid scintillators have the useful property of Pulse Shape Discrimination(PSD), which can be used to separate gamma-ray-induced events when the scintillators are used as neutron detectors. Because of their ability to apply PSD, these liquid scintillators will have many applications in neutron detection, such as a recent experiment conducted at the University of Notre Dame. The liquid scintillators use a xylene based liquid made in-house at Oak Ridge National Laboratory. Naphthalene in the liquid scintillator improves the light output properties of the scintillator. An optimized method for the purification of naphthalene will be discussed as well as the first implementation of an array of these detectors. This work is supported in part by the NSF and the U.S. DOE. Research sponsored by the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the U.S. Department of Energy.

  20. Non-toxic liquid scintillators with high light output based on phenyl-substituted siloxanes

    NASA Astrophysics Data System (ADS)

    Dalla Palma, M.; Carturan, S. M.; Degerlier, M.; Marchi, T.; Cinausero, M.; Gramegna, F.; Quaranta, A.

    2015-04-01

    The work describes the development of a new class of liquid scintillators based on polysiloxane liquid compounds. These materials are characterized by low toxicity, chemical inertness, very low volatility and low flammability, allowing their use without concerns even at high temperatures in vacuum. In this view different polysiloxane based liquids have been tested, with variable content and distribution of phenyl lateral substituents and added with suitable dyes, namely 2,5-diphenyloxazole (PPO) and Lumogen Violet (LV). Absorption and fluorescence spectroscopy have been used in order to study the emission feature of the various compounds and to investigate the spectral matching between siloxane solvents and dissolved primary dyes. Scintillation efficiency towards 60Co and 137Cs gamma rays, relative to commercial liquid scintillator (EJ-309), has been measured and the results have been related to the energy transfer and energy migration mechanism from monomer and excimer forming sites in liquid siloxanes.

  1. Method for measuring multiple scattering corrections between liquid scintillators

    SciTech Connect

    Verbeke, J. M.; Glenn, A. M.; Keefer, G. J.; Wurtz, R. E.

    2016-04-11

    In this study, a time-of-flight method is proposed to experimentally quantify the fractions of neutrons scattering between scintillators. An array of scintillators is characterized in terms of crosstalk with this method by measuring a californium source, for different neutron energy thresholds. The spectral information recorded by the scintillators can be used to estimate the fractions of neutrons multiple scattering. With the help of a correction to Feynman's point model theory to account for multiple scattering, these fractions can in turn improve the mass reconstruction of fissile materials under investigation.

  2. Method for measuring multiple scattering corrections between liquid scintillators

    NASA Astrophysics Data System (ADS)

    Verbeke, J. M.; Glenn, A. M.; Keefer, G. J.; Wurtz, R. E.

    2016-07-01

    A time-of-flight method is proposed to experimentally quantify the fractions of neutrons scattering between scintillators. An array of scintillators is characterized in terms of crosstalk with this method by measuring a californium source, for different neutron energy thresholds. The spectral information recorded by the scintillators can be used to estimate the fractions of neutrons multiple scattering. With the help of a correction to Feynman's point model theory to account for multiple scattering, these fractions can in turn improve the mass reconstruction of fissile materials under investigation.

  3. Method for measuring multiple scattering corrections between liquid scintillators

    DOE PAGES

    Verbeke, J. M.; Glenn, A. M.; Keefer, G. J.; ...

    2016-04-11

    In this study, a time-of-flight method is proposed to experimentally quantify the fractions of neutrons scattering between scintillators. An array of scintillators is characterized in terms of crosstalk with this method by measuring a californium source, for different neutron energy thresholds. The spectral information recorded by the scintillators can be used to estimate the fractions of neutrons multiple scattering. With the help of a correction to Feynman's point model theory to account for multiple scattering, these fractions can in turn improve the mass reconstruction of fissile materials under investigation.

  4. Laboratory studies on the removal of radon-born lead from KamLAND's organic liquid scintillator

    NASA Astrophysics Data System (ADS)

    Keefer, G.; Grant, C.; Piepke, A.; Ebihara, T.; Ikeda, H.; Kishimoto, Y.; Kibe, Y.; Koseki, Y.; Ogawa, M.; Shirai, J.; Takeuchi, S.; Mauger, C.; Zhang, C.; Schweitzer, G.; Berger, B. E.; Dazeley, S.; Decowski, M. P.; Detwiler, J. A.; Djurcic, Z.; Dwyer, D. A.; Efremenko, Y.; Enomoto, S.; Freedman, S. J.; Fujikawa, B. K.; Furuno, K.; Gando, A.; Gando, Y.; Gratta, G.; Hatakeyama, S.; Heeger, K. M.; Hsu, L.; Ichimura, K.; Inoue, K.; Iwamoto, T.; Kamyshkov, Y.; Karwowski, H. J.; Koga, M.; Kozlov, A.; Lane, C. E.; Learned, J. G.; Maricic, J.; Markoff, D. M.; Matsuno, S.; McKee, D.; McKeown, R. D.; Miletic, T.; Mitsui, T.; Motoki, M.; Nakajima, Kyo; Nakajima, Kyohei; Nakamura, K.; O`Donnell, T.; Ogawa, H.; Piquemal, F.; Ricol, J.-S.; Shimizu, I.; Suekane, F.; Suzuki, A.; Svoboda, R.; Tajima, O.; Takemoto, Y.; Tamae, K.; Tolich, K.; Tornow, W.; Watanabe, Hideki; Watanabe, Hiroko; Winslow, L. A.; Yoshida, S.

    2015-01-01

    The removal of radioactivity from liquid scintillator has been studied in preparation of a low background phase of KamLAND. This paper describes the methods and techniques developed to measure and efficiently extract radon decay products from liquid scintillator. We report the radio-isotope reduction factors obtained when applying various extraction methods. During this study, distillation was identified as the most efficient method for removing radon-born lead from liquid scintillator.

  5. Laboratory studies on the removal of radon-born lead from KamLAND׳s organic liquid scintillator

    DOE PAGES

    Keefer, G.; Grant, C.; Piepke, A.; ...

    2014-09-28

    We studied the removal of radioactivity from liquid scintillator in preparation of a low background phase of KamLAND. We describe the methods and techniques developed to measure and efficiently extract radon decay products from liquid scintillator. Lastly, we report the radio-isotope reduction factors obtained when applying various extraction methods. During this study, distillation was identified as the most efficient method for removing radon daughters from liquid scintillator.

  6. Laboratory studies on the removal of radon-born lead from KamLAND׳s organic liquid scintillator

    SciTech Connect

    Keefer, G.; Grant, C.; Piepke, A.; Ebihara, T.; Ikeda, H.; Kishimoto, Y.; Kibe, Y.; Koseki, Y.; Ogawa, M.; Shirai, J.; Takeuchi, S.; Mauger, C.; Zhang, C.; Schweitzer, G.; Berger, B. E.; Dazeley, S.; Decowski, M. P.; Detwiler, J. A.; Djurcic, Z.; Dwyer, D. A.; Efremenko, Y.; Enomoto, S.; Freedman, S. J.; Fujikawa, B. K.; Furuno, K.; Gando, A.; Gando, Y.; Gratta, G.; Hatakeyama, S.; Heeger, K. M.; Hsu, L.; Ichimura, K.; Inoue, K.; Iwamoto, T.; Kamyshkov, Y.; Karwowski, H. J.; Koga, M.; Kozlov, A.; Lane, C. E.; Learned, J. G.; Maricic, J.; Markoff, D. M.; Matsuno, S.; McKee, D.; McKeown, R. D.; Miletic, T.; Mitsui, T.; Motoki, M.; Nakajima, Kyo; Nakajima, Kyohei; Nakamura, K.; O׳Donnell, T.; Ogawa, H.; Piquemal, F.; Ricol, J. -S.; Shimizu, I.; Suekane, F.; Suzuki, A.; Svoboda, R.; Tajima, O.; Takemoto, Y.; Tamae, K.; Tolich, K.; Tornow, W.; Watanabe, Hideki; Watanabe, Hiroko; Winslow, L. A.; Yoshida, S.

    2014-09-28

    We studied the removal of radioactivity from liquid scintillator in preparation of a low background phase of KamLAND. We describe the methods and techniques developed to measure and efficiently extract radon decay products from liquid scintillator. Lastly, we report the radio-isotope reduction factors obtained when applying various extraction methods. During this study, distillation was identified as the most efficient method for removing radon daughters from liquid scintillator.

  7. Response of organic liquid scintillators to fast neutrons and gamma radiation

    NASA Astrophysics Data System (ADS)

    Hoertz, Paul G.; Mills, Karmann; Davis, Lynn; Baldasaro, Nicholas; Gupta, Vijay

    2013-03-01

    Liquid organic scintillators are cocktails of aromatic fluorophores in an aromatic solvent. They find widespread use in Liquid Scintillation Counters with applications in medical diagnostics as well as fundamental nuclear and particle physics. Ultima Gold™ XR, a commercially available organic liquid scintillator from Perkin Elmer, can be used in both aqueous and non-aqueous systems and is typically used for beta detection in medical diagnostics. Its performance under gamma radiation and neutron radiation is less well-characterized. Special and normal Ultima Gold™ XR liquid scintillators were exposed in separate experiments to fast neutrons and high energy photons from a nuclear reactor and to gamma rays from a Co-60 source. To perform the measurements in the radiation chamber, a custom light collection system consisting of a fiber optic cable, spectrometer and a diffuse reflecting optical cavity was fabricated. Advanced calibration procedures, traceable to NIST standards, were developed to determine photon fluxes and flux densities of the scintillators under ionizing radiation conditions. The scintillator emission spectra under gamma radiation from a Co-60 source and neutron radiation from a pool-type nuclear reactor were recorded and compared. Results on the spectrometer design and comparison of the spectra under different exposure are presented.

  8. Structural design of a high energy particle detector using liquid scintillator

    SciTech Connect

    Berg, Timothy John; /Minnesota U.

    1997-02-01

    This thesis presents a design for a 10,000 ton liquid scintillator neutrino detector being considered for the MINOS project at Fermilab. Details of designing, manufacturing, and assembling the active detector components are presented. The detector consists of 1080 magnetized steel absorber planes alternating with 1080 active detector planes. Each active plane is made up of plastic extrusions divided into nearly 400 cells for positional resolution. Life tests on the plastic extrusions determine their feasibility for containing the scintillator. The extrusions are sealed at the bottom, filled with liquid scintillator, and have an optical fiber running the entire length of each cell. The fibers terminate at the top of each extrusion in a manifold. An optical-fiber-light-guide connects the fibers in each manifold to a photo-detector. The photo-detector converts the light signals from the scintillator and optical fibers into electrical impulses for computer analysis.

  9. Characterizing Scitillation and Cherenkov Light Yield in Water-Based Liquid Scintillators

    NASA Astrophysics Data System (ADS)

    Land, B. J.; Caravaca, J.; Descamps, F. B.; Orebi Gann, G. D.

    2016-03-01

    The recent development of Water-based Liquid Scintillator (WbLS) has made it possible to produce scintillating materials with highly tunable light yields and excellent optical clarity. This allows for a straightforward combination of the directional properties of Cherenkov light with the greater energy resolution afforded by the typically brighter scintillation light, which lends itself well to a broad program of neutrino physics. Here we explore the light yields and optical properties of WbLS materials in development for Theia (formerly ASDC) as measured in our benchtop Theia R&D at Berkeley Lab and extrapolate to larger detectors.

  10. Preliminary study of the inclusion of Water-based Liquid Scintillator in the WATCHMAN Detector

    SciTech Connect

    Sweany, Melinda; Feng, Patrick L.; Marleau, Peter

    2015-02-01

    This note summarizes an effort to characterize the effects of adding water-based liquid scintillator to the WATCHMAN detector. A detector model was built in the Geant4 Monte Carlo toolkit, and the position reconstruction of positrons within the detector was compared with and without scintillator. This study highlights the need for further modeling studies and small-scale experimental studies before inclusion into a large-scale detector, as the benefits compared to the associated costs are unclear.

  11. Performance and Application of VUV-sensitive MPPCs for Liquid Argon Scintillation Light

    NASA Astrophysics Data System (ADS)

    Washimi, Tatsuki; Tanaka, Masashi; Yorita, Kohei

    A new type of the Multi-Pixel Photon Counter (MPPC), sensitive to liquid argon (LAr) scintillation light (wavelength = 128 nm), is recently developed and produced by Hamamatsu Photonics K.K. In this talk, we report the basic properties of the new MPPCs and the absolute photon detection efficiency (PDE) for LAr scintillation light. Comparisons of different MPPC types (with or without cross-talk supression and pixel sizes of 50 and 100 µm) are also presented.

  12. GEANT4 simulation of the response of a liquid scintillation counter

    NASA Astrophysics Data System (ADS)

    Hurtado, S.

    2017-09-01

    Liquid Scintillation Counting (LSC) is widely used as a very efficient technique for radioactivity quantification. LSC is a powerful tool applied as much in low level environmental radioactivity monitoring, as in radionuclide metrology for the activity standardization of electron capture, pure-beta, and alpha nuclides. In order to quantify the sample activity, the number of scintillation photons are counted by one or several PMTs. However, the scintillation count rate varies with the detection efficiency. As an alternative to traditional methods for the calculation of detection efficiency, a Monte Carlo approach based on GEANT4 toolkit is presented for the simulation of light emission inside a Quantulus 1220 liquid scintillation counter with two PMT photomultipliers tubes working in sum-coincidence mode. To this end, the GEANT4 simulation handles a variety of processes at optical wavelengths including refraction and reflection at medium boundaries, Rayleigh scattering and bulk absorption, and additional processes which produce optical photons such as Cherenkov effect, transition radiation and scintillation, and includes a description of optical properties associated with each material constituting the detection system. The objective is to simulate the propagation of optical photons from their creation in the liquid scintillation cocktail to the production of photoelectrons in the PMTs. In this paper, we report in detail the results of the proposed simulation (detection efficiency, and additionally wall effect and absorption probabilities of gamma-rays) for different radionuclides such as 14C, 3H, 54Mn and 90Y, and its validation through the comparison with the experimental measurements.

  13. Development of a low background liquid scintillation counter for a shallow underground laboratory.

    PubMed

    Erchinger, J L; Aalseth, C E; Bernacki, B E; Douglas, M; Fuller, E S; Keillor, M E; Morley, S M; Mullen, C A; Orrell, J L; Panisko, M E; Warren, G A; Williams, R O; Wright, M E

    2015-11-01

    Pacific Northwest National Laboratory has recently opened a shallow underground laboratory intended for measurement of low-concentration levels of radioactive isotopes in samples collected from the environment. The development of a low-background liquid scintillation counter is currently underway to further augment the measurement capabilities within this underground laboratory. Liquid scintillation counting is especially useful for measuring charged particle (e.g., β and α) emitting isotopes with no (or very weak) gamma-ray yields. The combination of high-efficiency detection of charged particle emission in a liquid scintillation cocktail coupled with the low-background environment of an appropriately designed shield located in a clean underground laboratory provides the opportunity for increased-sensitivity measurements of a range of isotopes. To take advantage of the 35m-water-equivalent overburden of the underground laboratory, a series of simulations have evaluated the scintillation counter's shield design requirements to assess the possible background rate achievable. This report presents the design and background evaluation for a shallow underground, low background liquid scintillation counter design for sample measurements. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Timing properties and pulse shape discrimination of LAB-based liquid scintillator

    NASA Astrophysics Data System (ADS)

    Li, Xiao-Bo; Xiao, Hua-Lin; Cao, Jun; Li, Jin; Ruan, Xi-Chao; Heng, Yue-Kun

    2011-11-01

    Linear Alkyl Benzene (LAB) is a promising liquid scintillator solvent in neutrino experiments because it has many appealing properties. The timing properties of LAB-based liquid scintillator have been studied through ultraviolet and ionization excitation in this study. The decay time of LAB, PPO and bis-MSB is found to be 48.6 ns, 1.55 ns and 1.5 ns, respectively. A model can describe the absorption and re-emission process between PPO and bis-MSB perfectly. The energy transfer time between LAB and PPO with different concentrations can be obtained via another model. We also show that the LAB-based liquid scintillator has good (n, γ) and (α, γ) discrimination power.

  15. Exploring detection of nuclearites in a large liquid scintillator neutrino detector

    NASA Astrophysics Data System (ADS)

    Guo, Wan-Lei; Xia, Cheng-Jun; Lin, Tao; Wang, Zhi-Min

    2017-01-01

    We take the JUNO experiment as an example to explore nuclearites in the future large liquid scintillator detector. Comparing to the previous calculations, the visible energy of nuclearites across the liquid scintillator will be reestimated for the liquid scintillator based detector. Then the JUNO sensitivities to the nuclearite flux are presented. It is found that the JUNO projected sensitivities can be better than 7.7 ×10-17 cm-2 s-1 sr-1 for the nuclearite mass 1 015 GeV ≤M ≤1 024 GeV and initial velocity 10-4≤β0≤10-1 with a 20 year running. Note that the JUNO will give the most stringent limits for downgoing nuclearites with 1.6 ×1 013 GeV ≤M ≤4.0 ×1 015 GeV and a typical galactic velocity β0=10-3.

  16. Calibration of an EJ309 liquid scintillator using an AmBe neutron source

    NASA Astrophysics Data System (ADS)

    Bai, Huaiyong; Wang, Zhimin; Zhang, Luyu; Lu, Yi; Jiang, Haoyu; Chen, Jinxiang; Zhang, Guohui

    2017-08-01

    As the light output function of the EJ309 liquid scintillator is nonlinear with respect to the energy of the recoil proton and it is difficult to be predicted, it need to be measured. In the present work, an EJ309 liquid scintillator, 5.1 cm in diameter and 5.1 cm in length, is calibrated with an AmBe neutron source using the time-of-flight method. A Monte Carlo simulation is performed to improve the accuracy of the measured light output function. The obtained light output function is presented and it is compared with existing measurements. The energy resolution of the EJ309 Liquid scintillator is also illustrated.

  17. Electrokinetic removal of radionuclides contained in scintillation liquids absorbed in soil type Phaeozem.

    PubMed

    Valdovinos, V; Monroy-Guzmán, F; Bustos, E

    2016-10-01

    Control samples of scintillation liquids - Phaeozem soil mixtures were prepared with different scintillation liquids as the support electrolyte, Install Gel(®) XF, (Ultima Gold AB™ and Ultima Gold XR™), to construct the polarization curves, and to select the cell potential with the highest mass transfer to remove (24)Na (15 h) and (99m)Tc (6 h) as radiotracers from polluted Phaeozem soil. During the electrokinetic treatment (EKT), the removal of radionuclides contained in scintillation liquids absorbed in Phaeozem soil, liquid phase was characterized by Gas Chromatography coupled with a Flame Ionization Detector (GC-FID) and Fourier Transform Infrared Spectrometry (FTIR), solids by FTIR, before and after the application of cell potential. In this sense, the support electrolyte was selected based on the highest current generated (1 mA), as in the case of scintillation liquid 50% Ultima Gold XR™ + 50% Water (1:1), which was used for 6 h in the presence of a mesh and a titanium rod, as anode and cathode, respectively. Finally, the removal percentage accumulated in the liquid phase after the EKT of Phaeozem soil polluted by (99m)Tc was 61% close to the anode after 4 h. It was also 61% for (24)Na close to cathode after 2 h, and after 4 h it was 71.8%.

  18. Liquid scintillators with near infrared emission based on organoboron conjugated polymers.

    PubMed

    Tanaka, Kazuo; Yanagida, Takayuki; Yamane, Honami; Hirose, Amane; Yoshii, Ryousuke; Chujo, Yoshiki

    2015-11-15

    The organic liquid scintillators based on the emissive polymers are reported. A series of conjugated polymers containing organoboron complexes which show the luminescence in the near infrared (NIR) region were synthesized. The polymers showed good solubility in common organic solvents. From the comparison of the luminescent properties of the synthesized polymers between optical and radiation excitation, similar emission bands were detected. In addition, less significant degradation was observed. These data propose that the organoboron conjugated polymers are attractive platforms to work as an organic liquid scintillator with the emission in the NIR region.

  19. Scintillation efficiency for low energy nuclear recoils in liquid xenon dark matter detectors

    NASA Astrophysics Data System (ADS)

    Mu, Wei; Xiong, Xiaonu; Ji, Xiangdong

    2015-02-01

    We perform a theoretical study of the scintillation efficiency of the low energy region crucial for liquid xenon dark matter detectors. We develop a computer program to simulate the cascading process of the recoiling xenon nucleus in liquid xenon and calculate the nuclear quenching effect due to atomic collisions. We use the electronic stopping power extrapolated from experimental data to the low energy region, and take into account the effects of electron escape from electron-ion pair recombination using the generalized Thomas-Imel model fitted to scintillation data. Our result agrees well with the experiments from neutron scattering and vanishes rapidly as the recoil energy drops below 3 keV.

  20. Oxygen quenching in a LAB based liquid scintillator and the nitrogen bubbling model

    NASA Astrophysics Data System (ADS)

    Xiao, Hua-Lin; Deng, Jing-Shan; Wang, Nai-Yan

    2010-05-01

    The oxygen quenching effect in a Linear Alkl Benzene (LAB) based liquid scintillator (LAB as the solvent, 3 g/L 2, 5 diphe-nyloxazole (PPO) as the fluor and 15 mg/L p-bis-(o-methylstyryl)-benzene (bis-MSB) as the λ-shifter) is studied by measuring the light yield as a function of the nitrogen bubbling time. It is shown that the light yield of the fully purged liquid scintillator is increased by 11% at room temperature and the room atmospheric pressure. A simple nitrogen bubbling model is proposed to describe the relationship between the relative light yield (oxygen quenching factor) and the bubbling time.

  1. Determination of Low Level Alpha and Beta Emitters Using Liquid-Liquid Extraction and a Liquid Scintillation Spectrometer

    NASA Astrophysics Data System (ADS)

    Yu, Yu-Fu; BjØRnstad, H. E.; Salbu, B.

    Two radiochemical procedures for determination of low level strontium-90 and plutonium-239+240 in environmental and biological materials using combined selective solvent extraction with low level liquid scintillation counting have been presented. Y-90, the daughter nuclide of Sr-90, and Pu-239+240 are selectively extracted from nitric acid solution into 5% di(-2ethylhexyl)phosphoric acid (HDEHP) in toluene and the radionuclides of interest in organic phase are counted with an ultra low level scintillation counter "Quantulus". The lower detection limits for Sr-90 and Pu-239+240 are estimated to be 20 mBq and 0.3 mBq respectively. The developed procedures have been tested for soma environmental and biological samples and the preminarly results show that they are more simple and time-saving than traditional methods.

  2. Determination of the thermal, oxidative and photochemical degradation rates of scintillator liquid by fluorescence EEM spectroscopy.

    PubMed

    Andrews, N L P; Fan, J Z; Forward, R L; Chen, M C; Loock, H-P

    2016-12-21

    The thermal, oxidative and photochemical stability of the scintillator liquid proposed for the SNO+ experiment has been tested experimentally using accelerated aging methods. The stability of the scintillator constituents was determined through fluorescence excitation emission matrix (EEM) spectroscopy and absorption spectroscopy, using parallel factor analysis (PARAFAC) as an multivariate analysis tool. By exposing the scintillator liquid to a well-known photon flux at 365 nm and by measuring the decay rate of the fluorescence shifters and the formation rate of their photochemical degradation products, we can place an upper limit on the acceptable photon flux as 1.38 ± 0.09 × 10(-11) photon mol L(-1). Similarly, the oxidative stability of the scintillator liquid was determined by exposure to air at several elevated temperatures. Through measurement of the corresponding activation energy it was determined that the average oxygen concentration would have to be kept below 4.3-7.1 ppbw (headspace partial pressure below 24 ppmv). On the other hand, the thermal stability of the scintillator cocktail in the absence of light and oxygen was remarkable and poses no concern to the SNO+ experiment.

  3. Development of liquid scintillator containing a zirconium complex for neutrinoless double beta decay experiment

    NASA Astrophysics Data System (ADS)

    Fukuda, Yoshiyuki; Moriyama, Shigetaka; Ogawa, Izumi

    2013-12-01

    An organic liquid scintillator containing a zirconium complex has been developed for a new neutrinoless double beta decay experiment. In order to produce a detector that has good energy resolution (4% at 2.5 MeV) and low background (0.1 counts/(t·year)) and that can monitor tons of target isotope, we chose a zirconium β-diketone complex having high solubility (over 10 wt%) in anisole. However, the absorption peak of the diketone ligand overlaps with the luminescence of anisole. Therefore, the light yield of the liquid scintillator decreases in proportion to the concentration of the complex. To avoid this problem, we synthesized a β-keto ester complex introducing -OC3H7 or -OC2H5 substituent groups in the β-diketone ligand, which shifted the absorption peak to around 245 nm, which is shorter than the emission peak of anisole (275 nm). However, the shift of the absorption peak depends on the polarity of the scintillation solvent. Therefore we must choose a low polarity solvent for the liquid scintillator. We also synthesized a Zr-ODZ complex, which has a high quantum yield (30%) and good emission wavelength (425 nm) with a solubility 5 wt% in benzonitrile. However, the absorption peak of the Zr-ODZ complex was around 240 nm. Therefore, it is better to use the scintillation solvent which has shorter luminescence wavelength than that of the aromatic solvent.

  4. SU-E-T-641: Proton Range Measurements Using a Geometrically Calibrated Liquid Scintillator Detector

    SciTech Connect

    Hui, C; Robertson, D; Alsanea, F; Beddar, S

    2015-06-15

    Purpose: The purpose of this work is to develop a geometric calibration method to accurately calculate physical distances within a liquid scintillator detector and to assess the accuracy, consistency, and robustness of proton beam range measurements when using a liquid scintillator detector system with the proposed geometric calibration process. Methods: We developed a geometric calibration procedure to accurately convert pixel locations in the camera frame into physical locations in the scintillator frame. To ensure accuracy, the geometric calibration was performed before each experiment. The liquid scintillator was irradiated with spot scanning proton beams of 94 energies in two deliveries. A CCD camera was used to capture the two-dimensional scintillation light profile of each of the proton energies. An algorithm was developed to automatically calculate the proton range from the acquired images. The measured range was compared to the nominal range to assess the accuracy of the detector. To evaluate the robustness of the detector between each setup, the experiments were repeated on three different days. To evaluate the consistency of the measurements between deliveries, three sets of measurements were acquired for each experiment. Results: Using this geometric calibration procedure, the proton beam ranges measured using the liquid scintillator system were all within 0.3mm of the nominal range. The average difference between the measured and nominal ranges was −0.20mm. The delivery-to-delivery standard deviation of the proton range measurement was 0.04mm, and the setup-to-setup standard deviation of the measurement was 0.10mm. Conclusion: The liquid scintillator system can measure the range of all 94 beams in just two deliveries. With the proposed geometric calibration, it can measure proton range with sub-millimeter accuracy, and the measurements were shown to be consistent between deliveries and setups. Therefore, we conclude that the liquid scintillator

  5. Evaluating analytical ionization quenching correction models for 3D liquid organic scintillator detector

    NASA Astrophysics Data System (ADS)

    Alsanea, F.; Beddar, S.

    2017-05-01

    Proton therapy offers dosimetric advantage over conventional photon therapy due to the finite range of the proton beam, which improves dose conformity. However, one of the main challenges of proton beam therapy is verification of the complex treatment plans delivered to a patient. Thus, 3D measurements are needed to verify the complex dose distribution. A 3D organic scintillator detector is capable of such measurements. However, organic scintillators exhibit a non-linear relation to the ionization density called ionization quenching. The ionization quenching phenomenon in organic scintillators must be accounted for to obtain accurate dose measurements. We investigated the energy deposition by secondary electrons (EDSE) model to explain ionization quenching in 3D liquid organic scintillator when exposed to proton beams. The EDSE model was applied to volumetric scintillation measurement of proton pencil beam with energies of 85.6, 100.9, 144.9 and 161.9 MeV. The quenching parameter in EDSE model ρq was determined by plotting the total light output vs the initial energy of the ion. The results were compared to the Birks semi-empirical formula of scintillation light emission.

  6. Development of a low background liquid scintillation counter for a shallow underground laboratory

    SciTech Connect

    Erchinger, Jennifer L.; Aalseth, Craig E.; Bernacki, Bruce E.; Douglas, Matthew; Fuller, Erin S.; Keillor, Martin E.; Morley, Shannon M.; Mullen, Crystal A.; Orrell, John L.; Panisko, Mark E.; Warren, Glen A.; Williams, Russell O.; Wright, Michael E.

    2015-08-20

    Pacific Northwest National Laboratory has recently opened a shallow underground laboratory intended for measurement of lowconcentration levels of radioactive isotopes in samples collected from the environment. The development of a low-background liquid scintillation counter is currently underway to further augment the measurement capabilities within this underground laboratory. Liquid scintillation counting is especially useful for measuring charged particle (e.g., B, a) emitting isotopes with no (orvery weak) gamma-ray yields. The combination of high-efficiency detection of charged particle emission in a liquid scintillation cocktail coupled with the low-background environment of an appropriately-designed shield located in a clean underground laboratory provides the opportunity for increased-sensitivity measurements of a range of isotopes. To take advantage of the 35-meter water-equivalent overburden of the underground laboratory, a series of simulations have evaluated the instrumental shield design requirements to assess the possible background rate achievable. This report presents the design and background evaluation for a shallow underground, low background liquid scintillation counter design for sample measurements.

  7. Low level liquid scintillation counter performance in a low level surface laboratory

    NASA Astrophysics Data System (ADS)

    Kaihola, L.; Kojola, H.; Kananen, R.

    1986-11-01

    A surface low level laboratory has been constructed where usage of special materials has reduced the gamma background to {1}/{20} of the standard laboratory, lowering the background in a low level liquid scintillation counter by 40 to 55% in C-14 window for sample volumes 15 to 3 ml.

  8. Effect of low electric fields on alpha scintillation light yield in liquid argon

    SciTech Connect

    Agnes, P.; Albuquerque, I. F. M.; Alexander, T.; Alton, A. K.; Asner, D. M.; Back, H. O.; Baldin, B.; Biery, K.; Bocci, V.; Bonfini, G.; Bonivento, W.; Bossa, M.; Bottino, B.; Brigatti, A.; Brodsky, J.; Budano, F.; Bussino, S.; Cadeddu, M.; Cadoni, M.; Calaprice, F.; Canci, N.; Candela, A.; Caravati, M.; Cariello, M.; Carlini, M.; Catalanotti, S.; Cavalcante, P.; Chepurnov, A.; Cicalò, C.; Cocco, A. G.; Covone, G.; D'Angelo, D.; D'Incecco, M.; Davini, S.; Cecco, S. De; Deo, M. De; Vincenzi, M. De; Derbin, A.; Devoto, A.; Eusanio, F. Di; Pietro, G. Di; Dionisi, C.; Edkins, E.; Empl, A.; Fan, A.; Fiorillo, G.; Fomenko, K.; Forster, G.; Franco, D.; Gabriele, F.; Galbiati, C.; Giagu, S.; Giganti, C.; Giovanetti, G. K.; Goretti, A. M.; Granato, F.; Gromov, M.; Guan, M.; Guardincerri, Y.; Hackett, B. R.; Herner, K.; Hughes, D.; Humble, P.; Hungerford, E. V.; Ianni, A.; James, I.; Johnson, T. N.; Jollet, C.; Keeter, K.; Kendziora, C. L.; Koh, G.; Korablev, D.; Korga, G.; Kubankin, A.; Li, X.; Lissia, M.; Loer, B.; Lombardi, P.; Longo, G.; Ma, Y.; Machulin, I. N.; Mandarano, A.; Mari, S. M.; Maricic, J.; Marini, L.; Martoff, C. J.; Meregaglia, A.; Meyers, P. D.; Milincic, R.; Miller, J. D.; Montanari, D.; Monte, A.; Mount, B. J.; Muratova, V. N.; Musico, P.; Napolitano, J.; Agasson, A. Navrer; Odrowski, S.; Oleinik, A.; Orsini, M.; Ortica, F.; Pagani, L.; Pallavicini, M.; Pantic, E.; Parmeggiano, S.; Pelczar, K.; Pelliccia, N.; Pocar, A.; Pordes, S.; Pugachev, D. A.; Qian, H.; Randle, K.; Ranucci, G.; Razeti, M.; Razeto, A.; Reinhold, B.; Renshaw, A. L.; Rescigno, M.; Riffard, Q.; Romani, A.; Rossi, B.; Rossi, N.; Rountree, D.; Sablone, D.; Saggese, P.; Sands, W.; Savarese, C.; Schlitzer, B.; Segreto, E.; Semenov, D. A.; Shields, E.; Singh, P. N.; Skorokhvatov, M. D.; Smirnov, O.; Sotnikov, A.; Stanford, C.; Suvorov, Y.; Tartaglia, R.; Tatarowicz, J.; Testera, G.; Tonazzo, A.; Trinchese, P.; Unzhakov, E. V.; Verducci, M.; Vishneva, A.; Vogelaar, B.; Wada, M.; Walker, S.; Wang, H.; Wang, Y.; Watson, A. W.; Westerdale, S.; Wilhelmi, J.; Wojcik, M. M.; Xiang, X.; Xiao, X.; Xu, J.; Yang, C.; Zhong, W.; Zhu, C.; Zuzel, G.

    2017-01-01

    Measurements were made of scintillation light yield of alpha particles from the $^{222}$Rn decay chain within the DarkSide-50 liquid argon time projection chamber. The light yield was found to increase as the applied electric field increased, with alphas in a 200 V/cm electric field exhibiting a 2% increase in light yield compared to alphas in no field.

  9. Effect of low electric fields on alpha scintillation light yield in liquid argon

    NASA Astrophysics Data System (ADS)

    Agnes, P.; Albuquerque, I. F. M.; Alexander, T.; Alton, A. K.; Asner, D. M.; Back, H. O.; Baldin, B.; Biery, K.; Bocci, V.; Bonfini, G.; Bonivento, W.; Bossa, M.; Bottino, B.; Brigatti, A.; Brodsky, J.; Budano, F.; Bussino, S.; Cadeddu, M.; Cadoni, M.; Calaprice, F.; Canci, N.; Candela, A.; Caravati, M.; Cariello, M.; Carlini, M.; Catalanotti, S.; Cavalcante, P.; Chepurnov, A.; Cicalò, C.; Cocco, A. G.; Covone, G.; D'Angelo, D.; D'Incecco, M.; Davini, S.; De Cecco, S.; De Deo, M.; De Vincenzi, M.; Derbin, A.; Devoto, A.; Di Eusanio, F.; Di Pietro, G.; Dionisi, C.; Edkins, E.; Empl, A.; Fan, A.; Fiorillo, G.; Fomenko, K.; Forster, G.; Franco, D.; Gabriele, F.; Galbiati, C.; Giagu, S.; Giganti, C.; Giovanetti, G. K.; Goretti, A. M.; Granato, F.; Gromov, M.; Guan, M.; Guardincerri, Y.; Hackett, B. R.; Herner, K.; Hughes, D.; Humble, P.; Hungerford, E. V.; Ianni, A.; James, I.; Johnson, T. N.; Jollet, C.; Keeter, K.; Kendziora, C. L.; Koh, G.; Korablev, D.; Korga, G.; Kubankin, A.; Li, X.; Lissia, M.; Loer, B.; Lombardi, P.; Longo, G.; Ma, Y.; Machulin, I. N.; Mandarano, A.; Mari, S. M.; Maricic, J.; Marini, L.; Martoff, C. J.; Meregaglia, A.; Meyers, P. D.; Milincic, R.; Miller, J. D.; Montanari, D.; Monte, A.; Mount, B. J.; Muratova, V. N.; Musico, P.; Napolitano, J.; Navrer Agasson, A.; Odrowski, S.; Oleinik, A.; Orsini, M.; Ortica, F.; Pagani, L.; Pallavicini, M.; Pantic, E.; Parmeggiano, S.; Pelczar, K.; Pelliccia, N.; Pocar, A.; Pordes, S.; Pugachev, D. A.; Qian, H.; Randle, K.; Ranucci, G.; Razeti, M.; Razeto, A.; Reinhold, B.; Renshaw, A. L.; Rescigno, M.; Riffard, Q.; Romani, A.; Rossi, B.; Rossi, N.; Rountree, D.; Sablone, D.; Saggese, P.; Sands, W.; Savarese, C.; Schlitzer, B.; Segreto, E.; Semenov, D. A.; Shields, E.; Singh, P. N.; Skorokhvatov, M. D.; Smirnov, O.; Sotnikov, A.; Stanford, C.; Suvorov, Y.; Tartaglia, R.; Tatarowicz, J.; Testera, G.; Tonazzo, A.; Trinchese, P.; Unzhakov, E. V.; Verducci, M.; Vishneva, A.; Vogelaar, B.; Wada, M.; Walker, S.; Wang, H.; Wang, Y.; Watson, A. W.; Westerdale, S.; Wilhelmi, J.; Wojcik, M. M.; Xiang, X.; Xiao, X.; Xu, J.; Yang, C.; Zhong, W.; Zhu, C.; Zuzel, G.

    2017-01-01

    Measurements were made of scintillation light yield of alpha particles from the 222Rn decay chain within the DarkSide-50 liquid argon time projection chamber. The light yield was found to increase as the applied electric field increased, with alphas in a 200 V/cm electric field exhibiting a ~2% increase in light yield compared to alphas in no field.

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

    SciTech Connect

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

    1981-01-01

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

  11. Measurement of the optical performance of liquid scintillator filled Teflon-fiber tubes

    SciTech Connect

    Zaman, S.M.

    1990-05-01

    A study of the optical performance of a liquid scintillator (BC517L) filled Teflon tube of inner diameter 0.06 cm, was carried out using a rectangular array of those tubes. Two experimental methods, the cosmic ray telescope and the direct scouce method, were used in measuring the light output (in photoelectrons) and the light attenuation length through the scintillator. Results showed the light output from this array for minimum ionizing charged particles to ba a fraction of a photoelectron (about 10{sup {minus}2}) and the attenuation length to be about 20.0 cm, for high energy particles, suggesting a limiting value for the tube diameter of the Teflon that can be used in scintillating fiber calorimeters for high energy physics experiments. 18 refs., 16 figs., 4 tabs.

  12. Searching for dark matter annihilation to monoenergetic neutrinos with liquid scintillation detectors

    SciTech Connect

    Kumar, J.; Sandick, P. E-mail: sandick@physics.utah.edu

    2015-06-01

    We consider searches for dark matter annihilation to monoenergetic neutrinos in the core of the Sun. We find that liquid scintillation neutrino detectors have enhanced sensitivity to this class of dark matter models, due to the energy and angular resolution possible for electron neutrinos and antineutrinos that scatter via charged-current interactions. In particular we find that KamLAND, utilizing existing data, could provide better sensitivity to such models than any current direct detection experiment for m{sub X} ∼< 15 Gev. KamLAND's sensitivity is signal-limited, and future liquid scintillation or liquid argon detectors with similar energy and angular resolution, but with larger exposure, will provide significantly better sensitivity. These detectors may be particularly powerful probes of dark matter with mass O(10) GeV.

  13. Searching for dark matter annihilation to monoenergetic neutrinos with liquid scintillation detectors

    SciTech Connect

    Kumar, J.; Sandick, P.

    2015-06-22

    We consider searches for dark matter annihilation to monoenergetic neutrinos in the core of the Sun. We find that liquid scintillation neutrino detectors have enhanced sensitivity to this class of dark matter models, due to the energy and angular resolution possible for electron neutrinos and antineutrinos that scatter via charged-current interactions. In particular we find that KamLAND, utilizing existing data, could provide better sensitivity to such models than any current direct detection experiment for m{sub X}≲15 Gev. KamLAND’s sensitivity is signal-limited, and future liquid scintillation or liquid argon detectors with similar energy and angular resolution, but with larger exposure, will provide significantly better sensitivity. These detectors may be particularly powerful probes of dark matter with mass O(10) GeV.

  14. An easy method for Ra-226 determination in river waters by liquid-scintillation counting

    NASA Astrophysics Data System (ADS)

    Moreno, H. P.; Vioque, I.; Manjón, G.; García-Tenorio, R.

    1999-01-01

    226Ra activity concentration in river water was determined using a low background liquid scintillation counter. Radium was extracted from the samples as Ra-BaSO4 precipitate which, afterwards, was dissolved with EDTA in ammonia medium. Solution was transferred into a low potassium glass vial and then mixed with a scintillation cocktail. Two different scintillation cocktails were selected for comparison. Efficiency, recovery yield and α/β separation were studied with both liquid scintillation cocktails. One single measurement, made one month after radium separation, allows to calculate the226Ra concentration as well as to assess the presence of alpha contamination of the sample. In the case of negligible interferences,224Ra concentrations can be subsequently evaluated in the same sample by the measurement made just after chemical separation of radium. This method has been applied for the determination of226Ra and224Ra activity concentrations in river water collected from different locations along the Odiel river estuary area (South-west of Spain). The presence of chemical industry, the wastes of which are released into the river, could be connected with radium activity concentration enhancements in the water.

  15. Feasibility study of a gadolinium-loaded DIN-based liquid scintillator

    NASA Astrophysics Data System (ADS)

    Song, Sook Hyung; Joo, Kyung Kwang; So, Sun Heang; Yeo, In Sung

    2013-09-01

    DIN (di-isopropylnaphthalene) has a high flashpoint and can be used as a base solvent in liquid scintillators. It reduces safety concerns to humans and the environment. (PPO, 3 g/ ℓ) and (bis-MSB, 30 mg/ ℓ) were dissolved to formulate a DIN-based liquid scintillator (LS). A gadolinium (Gd) complex with carboxylic acid was synthesized using a neutralized chemical reaction. Then, 0.1% Gd was loaded into the LS. This Gd-loaded DIN-based LS using a solvent-solvent extraction method is the first attempt at a LS. In this study, we investigated the physical and the optical properties of this LS, and we will summarize all the characteristics of the Gd-loaded DIN-based LS.

  16. Performance of a prototype active veto system using liquid scintillator for a dark matter search experiment

    NASA Astrophysics Data System (ADS)

    Park, J. S.; Adhikari, P.; Adhikari, G.; Oh, S. Y.; Kim, N. Y.; Kim, Y. D.; Ha, C.; Park, K. S.; Lee, H. S.; Jeon, E. J.

    2017-04-01

    We report the performance of an active veto system using a liquid scintillator with NaI(Tl) crystals for use in a dark matter search experiment. When a NaI(Tl) crystal is immersed in the prototype detector, the detector tags 48% of the internal 40K background in the 0-10 keV energy region. We also determined the tagging efficiency for events at 6-20 keV as 26.5±1.7% of the total events, which corresponds to 0.76±0.04 events/keV/kg/day. According to a simulation, approximately 60% of the background events from U, Th, and K radioisotopes in photomultiplier tubes are tagged at energies of 0-10 keV. Full shielding with a 40-cm-thick liquid scintillator can increase the tagging efficiency for both the internal 40K and external background to approximately 80%.

  17. Effect of low electric fields on alpha scintillation light yield in liquid argon

    DOE PAGES

    Agnes, P.; Albuquerque, I. F. M.; Alexander, T.; ...

    2017-01-24

    Measurements were made of scintillation light yield of alpha particles from themore » $$^{222}$$Rn decay chain within the DarkSide-50 liquid argon time projection chamber. Furthermore, the light yield was found to increase as the applied electric field increased, with alphas in a 200 V/cm electric field exhibiting a 2% increase in light yield compared to alphas in no field.« less

  18. The research program of the Liquid Scintillation Detector (LSD) in the Mont Blanc Laboratory

    NASA Technical Reports Server (NTRS)

    Dadykin, V. L.; Yakushev, V. F.; Korchagin, P. V.; Korchagin, V. B.; Malgin, A. S.; Ryassny, F. G.; Ryazhskaya, O. G.; Talochkin, V. P.; Zatsepin, G. T.; Badino, G.

    1985-01-01

    A massive (90 tons) liquid scintillation detector (LSD) has been running since October 1984 in the Mont Blanc Laboratory at a depth of 5,200 hg/sq cm of standard rock. The research program of the experiment covers a variety of topics in particle physics and astrophysics. The performance of the detector, the main fields of research are presented and the preliminary results are discussed.

  19. Polonium-210 assay using a background-rejecting extractive liquid-scintillation method

    SciTech Connect

    Case, C.N.; McDowell, W.J.

    1981-01-01

    This paper describes a procedure which combines solvent extraction with alpha liquid scintillation spectrometry. Pulse shape discrimination electronics are used to reject beta and gamma pulses and to lower the background count to acceptable levels. Concentration of /sup 210/Po and separation from interferring elements are accomplished using a H/sub 3/Po/sub 4/-HCl solution with TOPO combined with a scintillor in toluene. (DLC)

  20. Evaluation of the ultrasonic method for solubilizing Daphnia magna before liquid scintillation counting

    SciTech Connect

    Dauble, D.D.; Hanf, R.W. Jr.; Carlile, D.W.

    1984-11-01

    Adult Daphnia magna were exposed to /sup 14/C-labeled phenol and tissues analyzed for /sup 14/C uptake by three methods: (1) tissue solubilizer, (2) tissue solubilizer plus sonication, and (3) sonication alone. Analysis by liquid scintillation counting revealed that measurements of total activity among treatments were not significantly different (..cap alpha.. less than or equal to 0.10) at two count levels. Sonicated samples showed less variation than tissue samples that were solubilized. 5 references, 1 table.

  1. A liquid scintillator neutron multiplicity counter for assaying special nuclear material

    NASA Astrophysics Data System (ADS)

    Sheets, Steven; Glenn, A. M.; Kerr, P. L.; Kim, K. S.; Nakae, L. F.; Newby, R. J.; Prasad, M. K.; Snyderman, N. J.; Verbeke, J. M.; Wurtz, R. E.

    2010-11-01

    The use of 3-He detectors to infer the mass of a fissioning source from the statistical properties of the neutron multiplicity distribution is a mature technology. We describe a new neutron multiplicity counter using the fast timing of liquid scintillators for the non-destructive assay of special nuclear materials (SNM). A liquid scintillator multiplicity counter (LSMC) that detects fast fission neutrons makes possible a coincidence gate on the order of nanoseconds (vs. tens of microseconds for thermal counters). This allows a LSMC to assay SNM in high rate environments where the fission chains would overlap for a thermal counter. This includes items such as impure Pu with high (α,n) rates as well as low mass HEU where an active interrogation source is needed. Furthermore, the time-of-flight of correlated n-γ pairs allows the LSMC to act as an imager of SNM. We report on the development of a liquid scintillator multiplicity counter at Lawrence Livermore National Laboratory. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  2. Design of a Low Background Liquid Scintillation Counter for a Shallow Underground Laboratory

    NASA Astrophysics Data System (ADS)

    Orrell, John; Aalseth, Craig; Bernacki, Bruce; Douglas, Matt; Erchinger, Jennifer; Fuller, Erin; Keillor, Martin; Morley, Shannon; Mullen, Crystal; Panisko, Mark; Shaff, Sarah; Warren, Glen; Wright, Michael

    2014-09-01

    Pacific Northwest National Laboratory operates a 35-meter water-equivalent overburden, shallow underground laboratory for measuring low-concentration radioactive isotopes in environmental samples collected. A low-background liquid scintillation counter is under development. Liquid scintillation counting is useful for beta-emitting isotopes without (or low) gamma ray yields. The high-efficiency beta detection in a liquid scintillation cocktail coupled with the low-background environment of a shield located in a clean underground laboratory provides for increased-sensitivity measurements to a range of isotopes. Benchmarked simulations have evaluated the shield design requirements to assess the background rate achievable. Assay of shield construction materials provides the basis for the shield design development. The low background design is informed by efforts in experimental design of neutrinoless double beta decay experiments, direct detection dark matter experiments, and low energy neutrino detection experiments. In this vein a background budget for the instrument is presented with attention to low background methods directed toward applications of nuclear measurements.

  3. Neutron emission measurement at the HL-2A tokamak device with a liquid scintillation detector

    SciTech Connect

    Xie, Xufei; Chen, Zhongjing; Peng, Xingyu; Yuan, Xi; Zhang, Xing; Cui, Zhiqiang; Du, Tengfei; Hu, Zhimeng; Li, Tao; Fan, Tieshuan Chen, Jinxiang; Li, Xiangqing; Zhang, Guohui; Gorini, Giuseppe; Yuan, Guoliang; Yang, Jinwei; Yang, Qingwei

    2014-10-15

    Neutron emission measurement at the HL-2A tokamak device with a liquid scintillation detector is described. The detector was placed at a location with little structure material in the field of view, and equipped with a gain monitoring system which could provide the possibility to evaluate the gain variation as well as to correct for the detector response. Time trace of the neutron emissivity was obtained and it was consistent with the result of a standard {sup 235}U fission chamber. During the plasma discharge the neutron yield could vary by about four orders of magnitude and the fluctuation of the detector gain was up to about 6%. Pulse height spectrum of the liquid scintillation detector was constructed and corrected with the aid of the gain monitoring system, and the correction was found to be essential for the assessment of the neutron energy spectrum. This successful measurement offered experience and confidence for the application of liquid scintillation detectors in the upcoming neutron camera system.

  4. Development of an Ultra-Low Background Liquid Scintillation Counter for Trace Level Analysis

    SciTech Connect

    Erchinger, Jennifer L.; Orrell, John L.; Aalseth, Craig E.; Bernacki, Bruce E.; Douglas, Matthew; Finn, Erin C.; Fuller, Erin S.; Keillor, Martin E.; Morley, Shannon M.; Mullen, Crystal A.; Panisko, Mark E.; Shaff, Sarah M.; Warren, Glen A.; Wright, Michael E.

    2015-09-01

    Low-level liquid scintillation counting (LSC) has been established as one of the radiation detection techniques useful in elucidating environmental processes and environmental monitoring around nuclear facilities. The Ultra-Low Background Liquid Scintillation Counter (ULB-LSC) under construction in the Shallow Underground Laboratory at Pacific Northwest National Laboratory aims to further reduce the MDAs and/or required sample processing. Through layers of passive shielding in conjunction with an active veto and 30 meters water equivalent overburden, the background reduction is expected to be 10 to 100 times below typical analytic low-background liquid scintillation systems. Simulations have shown an expected background of around 14 counts per day. A novel approach to the light collection will use a coated hollow light guide cut into the inner copper shielding. Demonstration LSC measurements will show low-energy detection, spectral deconvolution, and alpha/beta discrimination capabilities, from trials with standards of tritium, strontium-90, and actinium-227, respectively. An overview of the system design and expected demonstration measurements will emphasize the potential applications of the ULB-LSC in environmental monitoring for treaty verification, reach-back sample analysis, and facility inspections.

  5. Characterization of a ^6Li-loaded organic liquid scintillator for fast neutron spectrometry

    NASA Astrophysics Data System (ADS)

    Bass, C. D.; Heimbach, C. R.; Nico, J. S.; Beise, E. J.; Breuer, H.; Erwin, D.; Langford, T.; Rodrigues, A.

    2010-11-01

    Fast neutrons induced by natural radioactivity and cosmic rays are important sources of background for low-background searches of dark matter, neutrinoless double beta decay, and solar neutrinos. One method for performing fast neutron spectroscopy involves a capture-gated coincidence between a fast neutron that thermalizes through elastic scattering within an organic scintillator and its subsequent capture on a nuclide having a high thermal neutron capture cross section. Thermalization within an organic scintillator occurs within a few ns, but the neutron capture time is typically of order 10s to 100s of μs. A capture signal preceded by a thermalization signal within a characteristic time can be used to select those fast neutrons that have deposited all of their kinetic energy into the scintillator, and the thermalization signal can provide spectroscopic information. We report on a number of measurements performed to characterize the properties of an organic liquid scintillator based on di-isopropyl naphthalene and loaded with ^6Li. This work has been carried out within a joint UMd and NIST project to develop a fast neutron spectrometer suitable for use in a deep underground, low-background laboratory. In particular, we report on measurements of optical properties, light yield, and fast neutron response.

  6. Scintillation efficiency of liquid argon in low energy neutron-argon scattering

    NASA Astrophysics Data System (ADS)

    Creus, W.; Allkofer, Y.; Amsler, C.; Ferella, A. D.; Rochet, J.; Scotto-Lavina, L.; Walter, M.

    2015-08-01

    Experiments searching for weak interacting massive particles with noble gases such as liquid argon require very low detection thresholds for nuclear recoils. A determination of the scintillation efficiency is crucial to quantify the response of the detector at low energy. We report the results obtained with a small liquid argon cell using a monoenergetic neutron beam produced by a deuterium-deuterium fusion source. The light yield relative to electrons was measured for six argon recoil energies between 11 and 120 keV at zero electric drift field.

  7. Recent Developments In Fast Neutron Detection And Multiplicity Counting With Verification With Liquid Scintillator

    SciTech Connect

    Nakae, L; Chapline, G; Glenn, A; Kerr, P; Kim, K; Ouedraogo, S; Prasad, M; Sheets, S; Snyderman, N; Verbeke, J; Wurtz, R

    2011-09-30

    For many years at LLNL, we have been developing time-correlated neutron detection techniques and algorithms for applications such as Arms Control, Threat Detection and Nuclear Material Assay. Many of our techniques have been developed specifically for the relatively low efficiency (a few percent) attainable by detector systems limited to man-portability. Historically, we used thermal neutron detectors (mainly {sup 3}He), taking advantage of the high thermal neutron interaction cross-sections. More recently, we have been investigating the use of fast neutron detection with liquid scintillators, inorganic crystals, and in the near future, pulse-shape discriminating plastics which respond over 1000 times faster (nanoseconds versus tens of microseconds) than thermal neutron detectors. Fast neutron detection offers considerable advantages, since the inherent nanosecond production time-scales of spontaneous fission and neutron-induced fission are preserved and measured instead of being lost by thermalization required for thermal neutron detectors. We are now applying fast neutron technology to the safeguards regime in the form of fast portable digital electronics as well as faster and less hazardous scintillator formulations. Faster detector response times and sensitivity to neutron momentum show promise for measuring, differentiating, and assaying samples that have modest to very high count rates, as well as mixed fission sources like Cm and Pu. We report on measured results with our existing liquid scintillator array, and progress on the design of a nuclear material assay system that incorporates fast neutron detection, including the surprising result that fast liquid scintillator detectors become competitive and even surpass the precision of {sup 3}He-based counters measuring correlated pairs in modest (kg) samples of plutonium.

  8. Recent Developments in Fast Neutron Detection and Multiplicity Counting with Liquid Scintillator

    SciTech Connect

    Nakae, L. F.; Chapline, G. F.; Glenn, A. M.; Kerr, P. L.; Kim, K. S.; Ouedraogo, S. A.; Prasad, M. K.; Sheets, S. A.; Snyderman, N. J.; Verbeke, J. M.; Wurtz, R. E.

    2011-12-13

    For many years, LLNL researchers have been developing time-correlated neutron detection techniques and algorithms for applications such as Arms Control, Threat Detection and Nuclear Material Assay. Many of the techniques have been developed specifically for the relatively low efficiency (a few percent) attainable by detector systems limited to man-portability. Historically, thermal neutron detectors (mainly {sup 3}He) were used, taking advantage of the high thermal neutron interaction cross sections. More recently, we have been investigating the use of fast neutron detection with liquid scintillators, inorganic crystals, and in the near future, pulse-shape discriminating plastics that respond over 1000 times faster (ns versus tens of {mu}s) than thermal neutron detectors. Fast neutron detection offers considerable advantages since the inherent ns production timescales of spontaneous fission and neutron-induced fission are preserved and measured instead of being lost by thermalization required for thermal neutron detectors. We are now applying fast neutron technology to the safeguards regime in the form of fast portable digital electronics as well as faster and less hazardous scintillator formulations. Faster detector response times and sensitivity to neutron momentum show promise for measuring, differentiating, and assaying samples that have modest to very high count rates, as well as mixed fission sources like Cm and Pu. We report on measured results with our existing liquid scintillator array and progress on the design of a nuclear material assay system that incorporates fast neutron detection, including the surprising result that fast liquid scintillator detectors become competitive and even surpass the precision of {sup 3}He-based counters measuring correlated pairs in modest (kg) samples of plutonium.

  9. Preliminary investigation of a luminescent colloidal quantum dots-based liquid scintillator

    NASA Astrophysics Data System (ADS)

    Delage, Marie-Ève; Lecavalier, Marie-Ève; Larivière, Dominic; Allen, Claudine Nì; Beaulieu, Luc

    2017-05-01

    Nanoparticles are appealing materials because of their versatility in addition to the uniqueness of their properties enabling one to use them in different applications. Radiation detection with colloidal quantum dots (cQDs) is one of the domains where the nanoscience entered lately. The luminescent nanocrystals that are cQDs are of particular interest in scintillation dosimetry, where they could play the role of the fluorophore in a liquid scintillator. The study presented in this paper investigates the response of a cQD-based liquid scintillator to X-ray radiation in order to characterize the dose and cQDs concentration dependence of the radioluminescence (RL) signal. For a beam energy of 180 kVp, the latter was found to be linear as a function of dose, with a majority of the signal (∼80%) coming from the cQDs and not the solvent, in this case hexane. Even with an ultra low concentration (μM), cQDs emit sufficient light to be detected. The RL intensity followed also a linear trend as a function of cQDs concentration, independently of the exposure time.

  10. Preliminary study of light yield dependence on LAB liquid scintillator composition

    NASA Astrophysics Data System (ADS)

    Ye, Xing-Chen; Yu, Bo-Xiang; Zhou, Xiang; Zhao, Li; Ding, Ya-Yun; Liu, Meng-Chao; Ding, Xue-Feng; Zhang, Xuan; Jie, Quan-Lin; Zhou, Li; Fang, Jian; Chen, Hai-Tao; Hu, Wei; Niu, Shun-Li; Yan, Jia-Qing; Zhao, Hang; Hong, Dao-Jin

    2015-09-01

    Liquid scintillator (LS) will be adopted as the detector material in JUNO (Jiangmen Underground Neutrino Observatory). The energy resolution requirement of JUNO is 3%, which has never previously been reached. To achieve this energy resolution, the light yield of liquid scintillator is an important factor. PPO (the fluor) and bis-MSB (the wavelength shifter) are the two main materials dissolved in LAB. To study the influence of these two materials on the transmission of scintillation photons in LS, 25 and 12 cm-long quartz vessels were used in a light yield experiment. LS samples with different concentration of PPO and bis-MSB were tested. At these lengths, the light yield growth is not obvious when the concentration of PPO is higher than 4 g/L. The influence from bis-MSB becomes insignificant when its concentration is higher than 8 mg/L. This result could provide some useful suggestions for the JUNO LS. Supported by Strategic Priority Research Program of Chinese Academy of Sciences (XDA10010500), National Natural Science Foundation of China (11390384) and CAS Center for Excellence in Particle Physics (CCEPP)

  11. Limits on low-energy neutrino fluxes with the Mont Blanc liquid scintillator detector

    NASA Astrophysics Data System (ADS)

    Aglietta, M.; Antonioli, P.; Badino, G.; Bologna, G.; Castagnoli, C.; Castellina, A.; Dadykin, V. L.; Fulgione, W.; Galeotti, P.; Khalchukov, F. F.; Korolkova, E. V.; Kortchaguin, P. V.; Kortchaguin, V. B.; Kudryavtsev, V. A.; Malguin, A. S.; Periale, L.; Ryassny, V. G.; Ryazhskaya, O. G.; Saavedra, O.; Trinchero, G.; Vernetto, S.; Yakushev, V. F.; Zatsepin, G. T.

    1992-11-01

    The LSD liquid scintillation detector has been operating since 1985 as an underground neutrino observatory in the Mont Blanc Laboratory with the main objective of detecting antineutrino bursts from collapsing stars. In August 1988 the construction of an additional lead and borex paraffin shield considerably reduced the radioactive background and increased the sensitivity of the apparatus. In this way the search for steady fluxes of low-energy neutrinos of different flavours through their interactions with free protons and carbon nuclei of the scintillator was made possible. No evidence for a galactic collapse was observed during the whole period of measurement. The corresponding 90% c.l. upper limit on the galactic collapses rate is 0.45 y -1 for a burst duration of ΔT ⩽ 10 s. After analysing the last 3 years data, the following 90% c.l. upper limits on the steady neutrino and antineutrino fluxes were obtained:

  12. A new gadolinium-loaded liquid scintillator for reactor neutrino detection

    NASA Astrophysics Data System (ADS)

    Ding, Yayun; Zhang, Zhiyong; Liu, Jinchang; Wang, Zhimin; Zhou, Pengju; Zhao, Yuliang

    2008-01-01

    A high flash point, low toxicity gadolinium-loaded liquid scintillator (Gd-LS) has been developed for the detection of reactor neutrino. Carboxylic acid 3,5,5-trimethylhexanoic acid is used as complexing ligand to form organo-complex with gadolinium chloride, and 2,5-diphenyloxazole (PPO), and 1,4-bis[2-methylstyryl]benzene (bis-MSB) are used as primary fluor and wavelength shifter, respectively. The scintillator base is linear alkyl benzene (LAB). The Gd-LS prepared with such recipe has long attenuation length, high light yield and long-term stability. Eight hundred liters of Gd-LS (1 g/L Gd) was synthesized and tested in a prototype detector at Institute of High Energy Physics. Preliminary results of the obviously peaks corresponding to neutron captured by H and Gd give an additional evidence that such Gd-LS are very promising for anti-neutrino detection.

  13. Initial evaluation of proportional scintillation in liquid Xenon for direct dark matter detection

    NASA Astrophysics Data System (ADS)

    Ye, T.; Giboni, K. L.; Ji, X.

    2014-12-01

    The Liquid Xenon Time Projection Chamber (LXeTPC) is often seen as an ideal detector for the direct Dark Matter (DM) search. In such experiments an efficient γ-ray background discrimination is essential. This can be achieved by distinguishing the ionization density, different for γ-rays and Nuclear Recoils. Two quantities are used for this measurement, the direct scintillation light generated by the ionizing event, and the free charges swept away by an electric field before recombination occurs. Present LXe detectors apply the Dual Phase principle, i.e. the charges are extracted into the gas phase and are measured by the proportional light they produce in a strong electric field in the gas. With ever growing dimensions of the detectors it is difficult to meet the tight mechanical tolerances required. Proportional scintillation also occurs in the liquid phase, although at much higher field strengths. Such field strengths can be reached in the 1/r field close to thin wires. All the limitations due to the extraction of electrons into the gas phase are avoided. Since the liquid level has not to be crossed, the design of the detector becomes simpler with many advantages over Dual Phase detectors. Our initial tests clearly show the pulses. They are much shorter, and their length is limited by longitudinal diffusion of the drifting charges. The threshold for proportional light production seems significantly lower, and estimates of the gain are more favorable than previously predicted. We attribute these discrepancies to our improved liquid purity.

  14. Occulting Light Concentrators in Liquid Scintillator Neutrino Detectors

    NASA Astrophysics Data System (ADS)

    Buizza Avanzini, Margherita; Cabrera, Anatael; Dusini, Stefano; Grassi, Marco; He, Miao; Wu, Wenjie

    2017-09-01

    The experimental efforts characterizing the era of precision neutrino physics revolve around collecting high-statistics neutrino samples and attaining an excellent energy and position resolution. Next generation liquid-based neutrino detectors, such as JUNO, HyperKamiokande, etc, share the use of a large target mass, and the need of pushing light collection to the edge for maximal calorimetric information. Achieving high light collection implies considerable costs, especially when considering detector masses of several kt. A traditional strategy to maximize the effective photo-coverage with the minimum number of PMTs relies on Light Concentrators (LC), such as Winston Cones. In this paper, the authors introduce a novel concept called Occulting Light Concentrators (OLC), whereby a traditional LC gets tailored to a conventional PMT, by taking into account its single-photoelectron collection efficiency profile and thus occulting the worst performing portion of the photocathode. Thus, the OLC shape optimization takes into account not only the optical interface of the PMT, but also the maximization of the PMT detection performances. The light collection uniformity across the detector is another advantage of the OLC system. By considering the case of JUNO, we will show OLC capabilities in terms of light collection and energy resolution.

  15. Prompt directional detection of galactic supernova by combining large liquid scintillator neutrino detectors

    NASA Astrophysics Data System (ADS)

    Fischer, V.; Chirac, T.; Lasserre, T.; Volpe, C.; Cribier, M.; Durero, M.; Gaffiot, J.; Houdy, T.; Letourneau, A.; Mention, G.; Pequignot, M.; Sibille, V.; Vivier, M.

    2015-08-01

    Core-collapse supernovae produce an intense burst of electron antineutrinos in the few-tens-of-MeV range. Several Large Liquid Scintillator-based Detectors (LLSD) are currently operated worldwide, being very effective for low energy antineutrino detection through the Inverse Beta Decay (IBD) process. In this article, we develop a procedure for the prompt extraction of the supernova location by revisiting the details of IBD kinematics over the broad energy range of supernova neutrinos. Combining all current scintillator-based detector, we show that one can locate a canonical supernova at 10 kpc with an accuracy of 45 degrees (68% C.L.). After the addition of the next generation of scintillator-based detectors, the accuracy could reach 12 degrees (68% C.L.), therefore reaching the performances of the large water Čerenkov neutrino detectors. We also discuss a possible improvement of the SuperNova Early Warning System (SNEWS) inter-experiment network with the implementation of a directionality information in each experiment. Finally, we discuss the possibility to constrain the neutrino energy spectrum as well as the mass of the newly born neutron star with the LLSD data.

  16. Prompt directional detection of galactic supernova by combining large liquid scintillator neutrino detectors

    SciTech Connect

    Fischer, V.; Chirac, T.; Lasserre, T. E-mail: tchirac@gmail.fr; and others

    2015-08-01

    Core-collapse supernovae produce an intense burst of electron antineutrinos in the few-tens-of-MeV range. Several Large Liquid Scintillator-based Detectors (LLSD) are currently operated worldwide, being very effective for low energy antineutrino detection through the Inverse Beta Decay (IBD) process. In this article, we develop a procedure for the prompt extraction of the supernova location by revisiting the details of IBD kinematics over the broad energy range of supernova neutrinos. Combining all current scintillator-based detector, we show that one can locate a canonical supernova at 10 kpc with an accuracy of 45 degrees (68% C.L.). After the addition of the next generation of scintillator-based detectors, the accuracy could reach 12 degrees (68% C.L.), therefore reaching the performances of the large water Čerenkov neutrino detectors. We also discuss a possible improvement of the SuperNova Early Warning System (SNEWS) inter-experiment network with the implementation of a directionality information in each experiment. Finally, we discuss the possibility to constrain the neutrino energy spectrum as well as the mass of the newly born neutron star with the LLSD data.

  17. Sample volume optimization for radon-in-water detection by liquid scintillation counting.

    PubMed

    Schubert, Michael; Kopitz, Juergen; Chałupnik, Stanisław

    2014-08-01

    Radon is used as environmental tracer in a wide range of applications particularly in aquatic environments. If liquid scintillation counting (LSC) is used as detection method the radon has to be transferred from the water sample into a scintillation cocktail. Whereas the volume of the cocktail is generally given by the size of standard LSC vials (20 ml) the water sample volume is not specified. Aim of the study was an optimization of the water sample volume, i.e. its minimization without risking a significant decrease in LSC count-rate and hence in counting statistics. An equation is introduced, which allows calculating the ²²²Rn concentration that was initially present in a water sample as function of the volumes of water sample, sample flask headspace and scintillation cocktail, the applicable radon partition coefficient, and the detected count-rate value. It was shown that water sample volumes exceeding about 900 ml do not result in a significant increase in count-rate and hence counting statistics. On the other hand, sample volumes that are considerably smaller than about 500 ml lead to noticeably lower count-rates (and poorer counting statistics). Thus water sample volumes of about 500-900 ml should be chosen for LSC radon-in-water detection, if 20 ml vials are applied.

  18. TDCR and CIEMAT/NIST Liquid Scintillation Methods applied to the Radionuclide Metrology

    NASA Astrophysics Data System (ADS)

    da Cruz, P. A. L.; da Silva, C. J.; Iwahara, A.; Loureiro, J. S.; De Oliveira, A. E.; Tauhata, L.; Lopes, R. T.

    2016-07-01

    This work presents TDCR and CIEMAT/NIST methods of liquid scintillation implemented in National Institutes of Metrology for activity standardization of radionuclides, which decay by beta emission and electron capture. The computer codes used to calculate the detection efficiency take into account: decay schemes, beta decay theory, quenching parameter evaluation, Poisson statistic model and Monte Carlo simulation for photon and particle interactions in the detection system. Measurements were performed for pure emitters 3H, 14C, 99Tc and for 68Ge/68Ga which decay by electron capture and positron emission, with uncertainties smaller than 1% (k = 1).

  19. Neutron detection in a high gamma ray background with liquid scintillators

    SciTech Connect

    Stevanato, L.; Cester, D.; Viesti, G.; Nebbia, G.

    2013-04-19

    The capability of liquid scintillator (namely 2'' Multiplication-Sign 2'' cells of EJ301 and EJ309) of detecting neutrons in a very high gamma ray background is explored. A weak {sup 252}Cf source has been detected in a high {sup 137}Cs gamma ray background corresponding to a dose rate of 100 {mu}Sv/h with probability of detection in compliance with IEC requirements for hand held instruments. Tests were performed with new generation of CAEN digitizers, in particular the V1720 (8 Channel 12bit 250 MS/s) one.

  20. The determination of low levels of cobalt-60 in environmental waters by liquid scintillation counting

    USGS Publications Warehouse

    Claassen, H.C.

    1970-01-01

    A method for determination of cobalt-60 in waters at levels greater than 0.5 pCi per sample is presented. A modification of the method may be used to analyze fluvial sediments and soils. After the cobalt has been separated, first as the hydroxide and then as the thiocyanate complex in methyl isobutyl ketone, it is counted in a liquid scintillation system at 80% efficiency. Separation factors achieved for six isotopes are generally greater than 2,000. The time for a single analysis, exclusive of the counting and evaporation operations, is about 2 h. ?? 1970.

  1. Uncertainties in 63Ni and 55Fe determinations using liquid scintillation counting methods.

    PubMed

    Herranz, M; Idoeta, R; Abelairas, A; Legarda, F

    2012-09-01

    The implementation of (63)Ni and (55)Fe determination methods in an environmental laboratory implies their validation. In this process, the uncertainties related to these methods should be analysed. In this work, the expression of the uncertainty of the results obtained using separation methods followed by liquid scintillation counting is presented. This analysis includes the consideration of uncertainties coming from the different alternatives which these methods use as well as those which are specific to the individual laboratory and the competency of its operators in applying the standard ORISE (Oak Ridge Institute for Science and Education) methods. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. A versatile and economic whole-body counter based on liquid scintillation detector modules.

    PubMed

    Smith, T; Cronquist, A G

    1977-05-01

    A whole-body counter comprising rectangular liquid scintillator detector modules is described. Photomultipliers are used economically and the use of local shielding leads to a further reduction in cost. In conjunction with a moving bed, the modular arrangement provides a versatile system which allows high sensitivity static counting using all detectors, or scan counting using selected combinations of detectors. The total body potassium content of a standard man (140 g K) can be estimated with a statistical counting error of 2.2% in a counting time of 1000 seconds. Methods of using the counter for total body potassium and gastro-intestinal absorption measurements are presented.

  3. Analysis of radioactive strontium-90 in food by Čerenkov liquid scintillation counting.

    PubMed

    Pan, Jingjing; Emanuele, Kathryn; Maher, Eileen; Lin, Zhichao; Healey, Stephanie; Regan, Patrick

    2017-01-27

    A simple liquid scintillation counting method using DGA/TRU resins for removal of matrix/radiometric interferences, Čerenkov counting for measuring (90)Y, and EDXRF for quantifying Y recovery was validated for analyzing (90)Sr in various foods. Analysis of samples containing energetic β emitters required using TRU resin to avoid false detection and positive bias. Additional 34% increase in Y recovery was obtained by stirring the resin while eluting Y with H2C2O4. The method showed acceptable accuracy (±10%), precision (10%), and detectability (~0.09Bqkg(-1)).

  4. Neutron-gamma discrimination employing pattern recognition of the signal from liquid scintillator

    NASA Astrophysics Data System (ADS)

    Kamada, Kohji; Enokido, Uhji; Ogawa, Seiji

    1999-05-01

    A pattern recognition method was applied to the neutron-gamma discrimination of the pulses from the liquid scintillator, NE-213. The circuit for the discrimination is composed of A/D converter, fast SCA, memory control circuit, two digital delay lines and two buffer memories. All components are packed on a small circuit board and are installed into a personal computer. Experiments using a weak 252Cf n-γ source were undertaken to test the feasibility of the circuit. The circuit is of very easy adjustment and, at the same time, of very economical price when compared with usual discrimination circuits, such as the TAC system.

  5. Comparison of (14)C liquid scintillation counting at NIST and NRC Canada.

    PubMed

    Bergeron, Denis E; Galea, Raphael; Laureano-Pérez, Lizbeth; Zimmerman, Brian E

    2016-03-01

    An informal bilateral comparison of (14)C liquid scintillation (LS) counting at the National Research Council of Canada (NRC) and the National Institute of Standards and Technology (NIST) has been completed. Two solutions, one containing (14)C-labeled sodium benzoate and one containing (14)C-labeled n-hexadecane, were measured at both laboratories. Despite observed LS cocktail instabilities, the two laboratories achieved accord in their standardizations of both solutions. At the conclusion of the comparison, the beta spectrum used for efficiency calculations was identified as inadequate and the data were reanalyzed with different inputs, improving accord. Published by Elsevier Ltd.

  6. Comparison of C-14 liquid scintillation counting at NIST and NRC Canada

    PubMed Central

    Bergeron, Denis E.; Galea, Raphael; Laureano-Pérez, Lizbeth; Zimmerman, Brian E.

    2016-01-01

    An informal bilateral comparison of 14C liquid scintillation (LS) counting at the National Research Council of Canada (NRC) and the National Institute of Standards and Technology (NIST) has been completed. Two solutions, one containing 14C-labeled sodium benzoate and one containing 14C-labeled n-hexadecane, were measured at both laboratories. Despite observed LS cocktail instabilities, the two laboratories achieved accord in their standardizations of both solutions. At the conclusion of the comparison, the beta spectrum used for efficiency calculations was identified as inadequate and the data were reanalyzed with different inputs, improving accord. PMID:26585641

  7. Plutonium and uranium determination in environmental samples: combined solvent extraction-liquid scintillation method.

    PubMed

    McDowell, W J; Farrar, D T; Billings, M R

    1974-12-01

    A method for the determination of uranium and plutonium by a combined high-resolution liquid scintillation-solvent extraction method is presented. Assuming a sample count equal to background count to be the detection limit, the lower detection limit for these and other alpha-emitting nuclides is 1.0 dpm with a Pyrex sample tube, 0.3 dpm with a quartz sample tube using present detector shielding or 0.02 d.p.m. with pulse-shape discrimination. Alpha-counting efficiency is 100%. With the counting data presented as an alpha-energy spectrum, an energy resolution of 0.2-0.3 MeV peak half-width and an energy identification to +/-0.1 MeV are possible. Thus, within these limits, identification and quantitative determination of a specific alpha-emitter, independent of chemical separation, are possible. The separation procedure allows greater than 98% recovery of uranium and plutonium from solution containing large amounts of iron and other interfering substances. In most cases uranium, even when present in 10(8)-fold molar ratio, may be quantitatively separated from plutonium without loss of the plutonium. Potential applications of this general analytical concept to other alpha-counting problems are noted. Special problems associated with the determination of plutonium in soil and water samples are discussed. Results of tests to determine the pulse-height and energy-resolution characteristics of several scintillators are presented. Construction of the high-resolution liquid scintillation detector is described.

  8. Performance characterization of a 3D liquid scintillation detector for discrete spot scanning proton beam systems

    NASA Astrophysics Data System (ADS)

    Darne, Chinmay D.; Alsanea, Fahed; Robertson, Daniel G.; Sahoo, Narayan; Beddar, Sam

    2017-07-01

    Existing systems for proton beam dosimetry are limited in their ability to provide a complete, accurate, and detailed account of volumetric dose distribution. In this work, we describe the design and development of a portable, fast, and reusable liquid scintillator-based three-dimensional (3D) optical detection system for use in proton therapy. Our long-term goal is to use this system clinically for beam characterization, dosimetry, and quality assurance studies of discrete spot scanning proton beam systems. The system used a 20  ×  20  ×  20 cm3 liquid scintillator volume. Three mutually orthogonal cameras surrounding this volume captured scintillation photons emitted in response to the proton beams. The cameras exhibited a mean spatial resolution of 0.21 mm over the complete detection volume and a temporal resolution of 11 ms. The system is shown to be capable of capturing all 94 beam energies delivered by a synchrotron and performing rapid beam range measurements with a mean accuracy of 0.073  ±  0.030 mm over all energies. The range measurement uncertainty for doses less than 1 cGy was found to be  ±0.355 mm, indicating high precision for low dose detection. Finally, we demonstrated that using multiple cameras allowed for the precise locations of the delivered beams to be tracked in 3D. We conclude that this detector is capable of real-time and accurate tracking of dynamic spot beam deliveries in 3D. The high-resolution light profiles it generates will be useful for future 3D construction of dose maps.

  9. Preparation and performance study of a novel liquid scintillator with mixed solvent as the matrix

    NASA Astrophysics Data System (ADS)

    Zheng, Zhanlong; Zhu, Jiayi; Luo, Xuan; Xu, Yewei; Zhang, Qianfeng; Zhang, Xing; Bi, Yutie; Zhang, Lin

    2017-04-01

    A novel liquid scintillator with the mixed solvent as the matrix was prepared for obtaining a good comprehensive performance. In this ternary liquid scintillator, the combination of 20% pseudocumene (PC) and 80% linear-alkyl benzene (LAB) by volume was chosen as the mixed solvent, and 2,5-diphenyloxazole (PPO) and 1,4-bis(2-Methylstyryl) benzene (bis-MSB) were as the primary fluor and wavelength shifter, respectively. The optimum prescription was obtained with regard to the light yield. Some characterizations based on the optimal formulation were conducted. The fluorescence emission spectra and wavelength-dependent optical attenuation length of the sample were measured by the fluorescence spectrophotometer and an UV-Vis spectrometer, respectively. The light yield was characterized by adopting the home-made optical platform device. The decay time was tested by adopting the time-correlated single photon counting (TCSPC) technique featured in high dynamic range of several orders of magnitude in light intensity. The experimental test results showed that the sample had a fairly good comprehensive performance.

  10. Determination of specific activity of iron-55 by spectrophotometry and liquid scintillation counting with bathophenanthroline complex

    SciTech Connect

    Yonezawa, C.; Hoshi, M.; Tachikawa, E.

    1985-12-01

    A method for determining the macroscopic amount of iron and its radioactivity (/sup 55/Fe) in radioactive corrosion products was established with a single chemical procedure. The iron was first extracted into a liquid scintillator (2,5-diphenyloxazole-xylene) as an ion associate of iron bathophenanthroline (BPT) complex and perchlorate at pH 3-8, followed by measurement of its radioactivity by a liquid scintillation counter and its absorbance by a spectrophotometer. The absorption maximum and molar absorptivity (epsilon) of the complex were 535 nm and 22,000, respectively. The system conforms to Beer's law at concentrations of up to 30 ..mu..g of iron in 10 mL of organic phase. The counting efficiency of the extracted /sup 55/Fe was found to be 60%. Although /sup 60/Co is extracted into the PPO-xylene together with /sup 5/)2%Fe, it is separated from /sup 55/Fe by back extraction with 0.005 M ethylenediaminetetraacetic acid (pH 6.0) into the aqueous phase. The effects of other foreign elements and radionuclides were also examined. The proposed method was successfully applied to analysis of radioactive corrosion products. 21 references, 6 figures, 3 tables.

  11. Determination of selected natural radionuclide concentrations in southwestern Caspian groundwater using liquid scintillation counting.

    PubMed

    Jowzaee, Sedigheh

    2013-12-01

    Twenty-seven spring water samples from southwestern shore of the Caspian Sea were analysed for their contents of gross alpha and beta, ²²²Rn, ²²⁶Ra and total uranium using a liquid scintillation counter (LSC). Other methods such as the Environmental Protection Agency (EPA) method 900 for gross alpha/beta measurement, radon emanation for ²²⁶Ra determination and laser fluorimetry for total uranium content were applied to make a comparison with the LSC technique. The levels of measured ²²²Rn and ²²⁶Ra range from 0.5 to 54 Bq l⁻¹ and from 14 to 297 mBq l⁻¹, respectively. The levels of gross alpha and beta are from 16 mBq l⁻¹ to 1.0 Bq l⁻¹ and from 22 to 630 mBq l⁻¹, respectively. The total uranium contents are from 3 to 66 mBq l⁻¹. It has been shown that the simple liquid scintillation counting technique could be applied conveniently for such studies where analysis of numerous samples is concerned.

  12. Laboratory Studies of Lead Removal from Liquid Scintillator in Preparation for KamLAND's Low Background Phase

    SciTech Connect

    Keefer, Gregory

    2011-04-27

    The removal of Radon induced Lead from liquid scintillator was extensively studied in preparation for KamLAND's low background phase. This work presents the results from laboratory experiments performed at the University of Alabama and their implications for KamLAND and future low background experiments using carbon based liquid scintillator. It was observed that distillation was the most effective purification procedure and that one must consider a non-polar and non-ionic component of Lead in order to reach the levels of radio-purity required for these new class of ultra-low background experiments.

  13. Performance of VUV-sensitive MPPC for liquid argon scintillation light

    NASA Astrophysics Data System (ADS)

    Igarashi, T.; Tanaka, M.; Washimi, T.; Yorita, K.

    2016-10-01

    A new multi-pixel photon counter (MPPC) sensitive to vacuum ultra-violet (VUV) light (wavelength λ < 150 nm) has recently been developed and produced by Hamamatsu Photonics K.K. In this study, the basic properties of the new MPPC are measured at the cryogenic facility of the Waseda University using liquid nitrogen. The temperature dependence of the breakdown voltage, capacitance, and dark count rate of the MPPCs are also evaluated. Using an 241Am α-ray source, the absolute photon detection efficiency (PDE) of the liquid argon (LAr) scintillation light (λ=128 nm) for the latest MPPC model is estimated to be 13%. Based on these basic measurements a possible application of the new MPPC to LAr detectors in dark matter search is suggested.

  14. Recent development in organic scintillators

    NASA Technical Reports Server (NTRS)

    Horrocks, D. L.; Wirth, H. O.

    1969-01-01

    Discussion on recent developments of organic scintillators includes studies of organic compounds that form glass-like masses which scintillate and are stable at room temperature, correlations between molecular structure of organic scintillators and self-quenching, recently developed fast scintillators, and applications of liquid-scintillation counters.

  15. Nd loaded liquid scintillator to search for 150Nd neutrinoless double beta decay

    NASA Astrophysics Data System (ADS)

    Barabanov, I.; Bezrukov, L.; Cattadori, C.; Danilov, N.; di Vacri, A.; Ianni, A.; Nisi, S.; Ortica, F.; Romani, A.; Salvo, C.; Smirnov, O.; Yanovich, E.

    2008-11-01

    The 150Nd is considered one of the most attractive candidate for searching neutrinoless double beta (0νββ-) decay, thanks to its high Q-value (3.367 MeV), that makes the external background issue less significative respect to other isotopes, and favorable computed matrix elements. The isotopic abundance of this isotope in natural neodimium is only 5.6% and up to now, it has been investigated only in low mass experiments. The next step is to increase the sensitivity of the experiments using larger mass of neodymium (10 ton-1 kton). This could be possible with a Nd loaded liquid scintillator (LS). At the Gran Sasso National Laboratory (LNGS), a joint INFN (Istituto Nazionale di Fisica Nucleare) and INR (Institute for Nuclear Research of Moscow) working group has been carrying out since 2001 an R&D activity aiming to develop organic liquid scintillators (LS) doped with metals. The achieved know-how and the satisfactory results obtained both with In and Gd allowed to face the development and production of Nd doped LS. The development of metal doped LS is challenging because the metal has to be embedded in a proper organic system that makes it soluble in an organic solvent minimizing the impact of the metal-organic compound on the optical and scintillation properties of the LS. A further challenge in the case of Nd is the presence of absorption bands of this element in the optical region with a transparent region around 400 nm, which is about at the maximum of the scintillator emission spectrum. A 2.5 1 Nd loaded LS has been produced diluting an originally developed Nd-Carboxylic (Nd-CBX) salt in pseudocumene (PC), the solvent of the Borexino liquid scintillator. The measured light yield, at [Nd] = 6.5 g/1 and [PPO] = 1.5 g/1, is ~ 75% of pure PC at the same fluor concentration (~ 10000 ph/MeV). The Nd doped LS has been tested in a 2 1 quartz cell (wrapped by VM2000 reflector film) having dimensions 5x5x100 cm3. The light propagates in the cell by total internal

  16. Computational aspects in modelling the interaction of low-energy X-rays with liquid scintillators.

    PubMed

    Grau Carles, A; Grau Malonda, A

    2006-01-01

    The commercial liquid scintillators available nowadays are mostly complex cocktails that frequently include non-negligible amounts of heavier elements than the commonly expected carbon or hydrogen. In May 1993, nine laboratories agreed to participate in the frame of the EUROMET project in a comparison of the activity concentration measurement of 55Fe. One particular aspect of the results that caught one's eye was a small systematic difference between the activity concentrations obtained with Ultima Gold and Insta Gel. The detection of the radiation emitted by EC nuclides involves, in addition to the atomic rearrangement generated by the capture of the electron by the nucleus, a frequently ignored secondary atomic rearrangement process due to photoionization. Such a process can be neglected for scintillators that only contain hydrogen and carbon, e.g., toluene, but must be taken into account when the EC nuclide solution is incorporated to cocktails with heavier elements, e.g., Ultima Gold. All along the present year, an improved version of the program EMI has been developed. This code adds the photoionization reduced energy correction to the previous versions, and successfully explains the systematic difference between the measured activity concentrations of 55Fe in Ultima Gold and Insta Gel.

  17. Combustion water purification techniques influence on OBT analysing using liquid scintillation counting method

    SciTech Connect

    Varlam, C.; Vagner, I.; Faurescu, I.; Faurescu, D.

    2015-03-15

    In order to determine organically bound tritium (OBT) from environmental samples, these must be converted into water, measurable by liquid scintillation counting (LSC). For this purpose we conducted some experiments to determine OBT level of a grass sample collected from an uncontaminated area. The studied grass sample was combusted in a Parr bomb. However usual interfering phenomena were identified: color or chemical quench, chemiluminescence, overlap over tritium spectrum because of other radionuclides presence as impurities ({sup 14}C from organically compounds, {sup 36}Cl as chloride and free chlorine, {sup 40}K as potassium cations) and emulsion separation. So the purification of the combustion water before scintillation counting appeared to be essential. 5 purification methods were tested: distillation with chemical treatment (Na{sub 2}O{sub 2} and KMnO{sub 4}), lyophilization, chemical treatment (Na{sub 2}O{sub 2} and KMnO{sub 4}) followed by lyophilization, azeotropic distillation with toluene and treatment with a volcanic tuff followed by lyophilization. After the purification step each sample was measured and the OBT measured concentration, together with physico-chemical analysis of the water analyzed, revealed that the most efficient method applied for purification of the combustion water was the method using chemical treatment followed by lyophilization.

  18. Pulse-shape discrimination and energy resolution of a liquid-argon scintillator with xenon doping

    NASA Astrophysics Data System (ADS)

    Wahl, C. G.; Bernard, E. P.; Lippincott, W. H.; Nikkel, J. A.; Shin, Y.; McKinsey, D. N.

    2014-06-01

    Liquid-argon scintillation detectors are used in fundamental physics experiments and are being considered for security applications. Previous studies have suggested that the addition of small amounts of xenon dopant improves performance in light or signal yield, energy resolution, and particle discrimination. In this study, we investigate the detector response for xenon dopant concentrations from 9 ± 5 ppm to 1100 ± 500 ppm xenon (by weight) in 6 steps. The 3.14-liter detector uses tetraphenyl butadiene (TPB) wavelength shifter with dual photomultiplier tubes and is operated in single-phase mode. Gamma-ray-interaction signal yield of 4.0 ± 0.1 photoelectrons/keV improved to 5.0 ± 0.1 photoelectrons/keV with dopant. Energy resolution at 662 keV improved from (4.4 ± 0.2)% (σ) to (3.5 ± 0.2)% (σ) with dopant. Pulse-shape discrimination performance degraded greatly at the first addition of dopant, slightly improved with additional additions, then rapidly improved near the end of our dopant range, with performance becoming slightly better than pure argon at the highest tested dopant concentration. Some evidence of reduced neutron scintillation efficiency with increasing dopant concentration was observed. Finally, the waveform shape outside the TPB region is discussed, suggesting that the contribution to the waveform from xenon-produced light is primarily in the last portion of the slow component.

  19. Preparation of Gd Loaded Liquid Scintillator for Daya Bay Neutrino Experiment

    NASA Astrophysics Data System (ADS)

    Ya-yun, Ding; Zhi-yong, Zhang

    2010-05-01

    Gadolinium loaded liquid scintillator (Gd-LS) is an excellent target material for reactor antineutrino experiments. Ideal Gd-LS should have long attenuation length, high light yield, long term stability, low toxicity, and should be compatible with the material used to build the detector. We have developed a new Gd-LS recipe in which carboxylic acid 3,5,5-trimethylhexanoic acid is used as the complexing ligand to gadolinium, 2,5-diphenyloxazole (PPO) and 1,4-bis[2-methylstyryl]benzene (bis-MSB) are used as primary fluor and wavelength shifter, respectively. The scintillator base is linear alkyl benzene (LAB). Eight hundred liters of Gd-LS has been synthesized and tested in a prototype detector. Results show that the Gd-LS has high quality and is suitable for underground experiments in large quantity. Large scale production facility has been built. A full batch production of 4 t Gd-LS has been produced and monitored for several months. The production of 180 t Gd-LS will be carried out in the near future.

  20. Preparation of Gd Loaded Liquid Scintillator for Daya Bay Neutrino Experiment

    SciTech Connect

    Ding Yayun; Zhang Zhiyong

    2010-05-12

    Gadolinium loaded liquid scintillator (Gd-LS) is an excellent target material for reactor antineutrino experiments. Ideal Gd-LS should have long attenuation length, high light yield, long term stability, low toxicity, and should be compatible with the material used to build the detector. We have developed a new Gd-LS recipe in which carboxylic acid 3,5,5-trimethylhexanoic acid is used as the complexing ligand to gadolinium, 2,5-diphenyloxazole (PPO) and 1,4-bis[2-methylstyryl]benzene (bis-MSB) are used as primary fluor and wavelength shifter, respectively. The scintillator base is linear alkyl benzene (LAB). Eight hundred liters of Gd-LS has been synthesized and tested in a prototype detector. Results show that the Gd-LS has high quality and is suitable for underground experiments in large quantity. Large scale production facility has been built. A full batch production of 4 t Gd-LS has been produced and monitored for several months. The production of 180 t Gd-LS will be carried out in the near future.

  1. Apparatus for positioning an external radioactive standard in a liquid scintillation counter

    SciTech Connect

    Horrocks, D.L.; Kampf, R.S.

    1987-07-07

    This patent describes a liquid scintillation counter having a counting chamber for receiving a sample containing a scintillator substance and a sample of a radioactive substance to be counted. The improved apparatus positions a radioactive source in an operating location to irradiate the sample in the counting chamber comprising, in combination: (1) a continuous bidirectionally flexible conveyor forming a closed loop for conveying the radioactive source through on operating location and a storage location; (2) means supporting the radioactive source at a position along the flexible conveyor for conveyance; (3) guide means for supporting the conveyor and for guiding conveyor movement along a selected path, the path transversing at spaced positions the storage location for the radioactive source remote from the counting chamber and the operating location for the radioactive source near to the counting chamber; and (4) drive means coupled to the continuous flexible conveyor to draw the conveyor around the path for conveying the radioactive source through the spaced storage and operating locations.

  2. Tomographic analysis of neutron and gamma pulse shape distributions from liquid scintillation detectors at Joint European Torus

    SciTech Connect

    Giacomelli, L.; Conroy, S.; Gorini, G.; Horton, L.; Murari, A.; Popovichev, S.; Syme, D. B.

    2014-02-15

    The Joint European Torus (JET, Culham, UK) is the largest tokamak in the world devoted to nuclear fusion experiments of magnetic confined Deuterium (D)/Deuterium-Tritium (DT) plasmas. Neutrons produced in these plasmas are measured using various types of neutron detectors and spectrometers. Two of these instruments on JET make use of organic liquid scintillator detectors. The neutron emission profile monitor implements 19 liquid scintillation counters to detect the 2.45 MeV neutron emission from D plasmas. A new compact neutron spectrometer is operational at JET since 2010 to measure the neutron energy spectra from both D and DT plasmas. Liquid scintillation detectors are sensitive to both neutron and gamma radiation but give light responses of different decay time such that pulse shape discrimination techniques can be applied to identify the neutron contribution of interest from the data. The most common technique consists of integrating the radiation pulse shapes within different ranges of their rising and/or trailing edges. In this article, a step forward in this type of analysis is presented. The method applies a tomographic analysis of the 3-dimensional neutron and gamma pulse shape and pulse height distribution data obtained from liquid scintillation detectors such that n/γ discrimination can be improved to lower energies and additional information can be gained on neutron contributions to the gamma events and vice versa.

  3. Tomographic analysis of neutron and gamma pulse shape distributions from liquid scintillation detectors at Joint European Torus.

    PubMed

    Giacomelli, L; Conroy, S; Gorini, G; Horton, L; Murari, A; Popovichev, S; Syme, D B

    2014-02-01

    The Joint European Torus (JET, Culham, UK) is the largest tokamak in the world devoted to nuclear fusion experiments of magnetic confined Deuterium (D)/Deuterium-Tritium (DT) plasmas. Neutrons produced in these plasmas are measured using various types of neutron detectors and spectrometers. Two of these instruments on JET make use of organic liquid scintillator detectors. The neutron emission profile monitor implements 19 liquid scintillation counters to detect the 2.45 MeV neutron emission from D plasmas. A new compact neutron spectrometer is operational at JET since 2010 to measure the neutron energy spectra from both D and DT plasmas. Liquid scintillation detectors are sensitive to both neutron and gamma radiation but give light responses of different decay time such that pulse shape discrimination techniques can be applied to identify the neutron contribution of interest from the data. The most common technique consists of integrating the radiation pulse shapes within different ranges of their rising and/or trailing edges. In this article, a step forward in this type of analysis is presented. The method applies a tomographic analysis of the 3-dimensional neutron and gamma pulse shape and pulse height distribution data obtained from liquid scintillation detectors such that n/γ discrimination can be improved to lower energies and additional information can be gained on neutron contributions to the gamma events and vice versa.

  4. An alpha–gamma coincidence spectrometer based on the Photon–Electron Rejecting Alpha Liquid Scintillation (PERALS®) system

    DOE PAGES

    Cadieux, J. R.; Fugate, G. A.; King, III, G. S.

    2015-02-07

    Here, an alpha–gamma coincidence spectrometer has been developed for the measurement of selected actinide isotopes in the presence of high beta/gamma fields. The system is based on a PERALS® liquid scintillation counter for beta/alpha discrimination and was successfully tested with both high purity germanium and bismuth germanate, gamma-ray detectors using conventional analog electronics.

  5. Liquid scintillation counting of polycarbonates: a sensitive technique for measurement of activity concentration of some radioactive noble gases.

    PubMed

    Mitev, K; Zhivkova, V; Pressyanov, D; Georgiev, S; Dimitrova, I; Gerganov, G; Boshkova, T

    2014-11-01

    This work explores the application of the liquid scintillation counting of polycarbonates for measurement of the activity concentration of radioactive noble gases. Results from experimental studies of the method are presented. Potential applications in the monitoring of radioactive noble gases are discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Optimization of liquid scintillation measurements applied to smears and aqueous samples collected in industrial environments

    NASA Astrophysics Data System (ADS)

    Chapon, Arnaud; Pigrée, Gilbert; Putmans, Valérie; Rogel, Gwendal

    Search for low-energy β contaminations in industrial environments requires using Liquid Scintillation Counting. This indirect measurement method supposes a fine control from sampling to measurement itself. Thus, in this paper, we focus on the definition of a measurement method, as generic as possible, for both smears and aqueous samples' characterization. That includes choice of consumables, sampling methods, optimization of counting parameters and definition of energy windows, using the maximization of a Figure of Merit. Detection limits are then calculated considering these optimized parameters. For this purpose, we used PerkinElmer Tri-Carb counters. Nevertheless, except those relative to some parameters specific to PerkinElmer, most of the results presented here can be extended to other counters.

  7. Development of an Array of Liquid Scintillators to Measure the Prompt Fission Neutron Spectrum at LANSCE

    NASA Astrophysics Data System (ADS)

    Perdue, B. A.; Taddeucci, T. N.; Haight, R. C.; Bredeweg, T.; Devlin, M.; Fotiades, N.; Jandel, M.; Laptev, A.; Lee, H. Y.; Nelson, R. O.; O'Donnell, J. M.; Ullmann, J. L.; Wender, S. A.; Wu, C. Y.; Kwan, E.; Chyzh, A.; Henderson, R. A.; Gostic, J. M.

    2014-05-01

    Higher quality measurements of outgoing prompt neutron spectra from neutron-induced fission as a function of the incoming neutron energy are needed. These data can be used in designing new fast reactors, predicting criticality for safety analyses, and developing techniques for global security applications. As part of the program to measure the prompt fission neutron spectra (PFNS) from the fission of 239Pu at the Los Alamos Neutron Science Center, we are developing a new array of liquid-scintillator detectors. This array will be used to measure the PFNS over a range of outgoing neutron energies from approximately 600 keV to 12 MeV and incident neutron energies from 0.5 to 30 MeV. A complete characterization of the detectors and the array as a whole will be carried out, targeted at understanding the light-output curves, efficiencies, and the neutron multiple-scattering backgrounds.

  8. Neutron detection in nuclear astrophysics experiments: study of organic liquid scintillators

    NASA Astrophysics Data System (ADS)

    Ciani, Giovanni Francesco

    2016-02-01

    In order to study the nuclear reaction 13 C(α,n)16 O, crucial for the nucleosynthesis of heavy nuclei (A>58), the LUNA collaboration at Laboratori Nazionali del Gran Sasso, is looking for the best neutron detector to use in the set up. One of the possibilities is to use detectors based on cell filled with Organic Liquid Scintillator BC501A. These detectors are sensible to fast neutron, but also to gamma rays. A Pulse Shape Discrimination process using the Zero Crossing method has been performed to select only signals from neutrons. Comparing the neutron spectra after the Pulse Shape Discrimination and the spectrum from a GEANT4 simulations, the efficiency of the BC501A, in function of the neutron energy and varying the light threshold, has been evaluated.

  9. Theoretical study of structure and stability of small gadolinium carboxylate complexes in liquid scintillator solvents.

    PubMed

    Huang, Pin-Wen

    2014-09-01

    The structural properties of three small gadolinium carboxylate complexes in three liquid scintillator solvents (pseudocumene, linear alkylbenzene, and phenyl xylylethane) were theoretically investigated using density functional theory (B3LYP/LC-RECP) and polarizable continuum model (PCM). The average interaction energy between gadolinium atom and carboxylate ligand (E(int)) and the energy difference of the highest singly occupied molecular orbital and lowest unoccupied molecular orbital (Δ(SL)) were calculated to evaluate and compare the relative stability of these complexes in solvents. The calculation results show that the larger (with a longer alkyl chain) gadolinium carboxylate complex has greater stability than the smaller one, while these gadolinium carboxylates in linear alkylbenzene were found to have greater stability than those in the other two solvents.

  10. Discriminating cosmic muons and radioactivity using a liquid scintillation fiber detector

    NASA Astrophysics Data System (ADS)

    Zhang, Y. P.; Xu, J. L.; Lu, H. Q.; Zhang, P.; Zhang, C. C.; Yang, C. G.

    2017-03-01

    In the case of underground experiments for neutrino physics or rare event searches, the background caused by cosmic muons contributes significantly and therefore must be identified and rejected. We proposed and optimized a new detector using liquid scintillator with wavelenghth-shifting fibers which can be employed as a veto detector for cosmic muons background rejection. From the prototype study, it has been found that the detector has good performances and is capable of discriminating between muons induced signals and environmental radiation background. Its muons detection efficiency is greater than 98%, and on average, 58 photo-electrons (p.e.) are collected when a muon passes through the detector. To optimize the design and enhance the collection of light, the reflectivity of the coating materials has been studied in detail. A Monte Carlo simulation of the detector has been developed and compared to the performed measurements showing a good agreement between data and simulation results.

  11. Standardization of 241Am by digital coincidence counting, liquid scintillation counting and defined solid angle counting.

    PubMed

    Balpardo, C; Capoulat, M E; Rodrigues, D; Arenillas, P

    2010-01-01

    The nuclide (241)Am decays by alpha emission to (237)Np. Most of the decays (84.6%) populate the excited level of (237)Np with energy of 59.54 keV. Digital coincidence counting was applied to standardize a solution of (241)Am by alpha-gamma coincidence counting with efficiency extrapolation. Electronic discrimination was implemented with a pressurized proportional counter and the results were compared with two other independent techniques: Liquid scintillation counting using the logical sum of double coincidences in a TDCR array and defined solid angle counting taking into account activity inhomogeneity in the active deposit. The results show consistency between the three methods within a limit of a 0.3%. An ampoule of this solution will be sent to the International Reference System (SIR) during 2009. Uncertainties were analysed and compared in detail for the three applied methods.

  12. Suppression of gamma-ray sensitivity of liquid scintillators for neutron detection

    NASA Astrophysics Data System (ADS)

    Swiderski, L.; Moszyński, M.; Wolski, D.; Iwanowska, J.; Szczęśniak, T.; Schotanus, P.; Hurlbut, C.

    2011-10-01

    Methods to reduce gamma-ray sensitivity of a liquid scintillator EJ309 have been studied. Zero-crossing pulse shape discrimination method was used to separate events generated by neutron and gamma radiation between 60- keVee and 4 MeVee. The measurements were carried out under irradiation from an intense 137Cs source, yielding dose rate of 10 mR/h at the detector. A Pu-Be source was used to establish neutron integration window. Pile-up rejection (PUR) circuit was used to reduce gamma-ray induced events under irradiation from an intense gamma-ray source. Further, application of lead, tin and copper shields was done in order to decrease intrinsic gamma-neutron detection efficiency.

  13. Extractive procedure for uranium determination in water samples by liquid scintillation counting.

    PubMed

    Gomez Escobar, V; Vera Tomé, F; Lozano, J C; Martín Sánchez, A

    1998-07-01

    An extractive procedure for uranium determination using liquid scintillation counting with the URAEX cocktail is described. Interference from radon and a strong influence of nitrate ion were detected in this procedure. Interference from radium, thorium and polonium emissions were very low when optimal operating conditions were reached. Quenching effects were considered and the minimum detectable activity was evaluated for different sample volumes. Isotopic analysis of samples can be performed using the proposed method. Comparisons with the results obtained with the general procedure used in alpha spectrometry with passivated implanted planar silicon detectors showed good agreement. The proposed procedure is thus suitable for uranium determination in water samples and can be considered as an alternative to the laborious conventional chemical preparations needed for alpha spectrometry methods using semiconductor detectors.

  14. Results of the liquid scintillation detector of the Mont Blanc Laboratory

    NASA Astrophysics Data System (ADS)

    Aglietta, M.; Badino, G.; Bologna, G. F.; Castagnoli, C.; Fulgione, W.

    1986-04-01

    Preliminary results research on collapsing-star neutrino bursts and cosmic-ray muons, obtained using the 90-ton 72 element liquid-scintillation detector (LSD) at Mt. Blanc Laboratory since October 1984, are presented in tables and graphs and characterized. The theoretically expected energy and time values for neutrinos from collapsing stars of 2 solar mass are calculated, and it is shown that no burst with multiplicity 6 or greater and Delta t 30 s or less was detected in 4 mo of LSD live time, corresponding to a preliminary upper limit of 3/yr for Galactic stellar collapses. About 3 muons/h crossing at least two counters were observed, and detection of aobut 700 muon bundles per year of multiplicity 2 or greater or 90 bundles per year of multiplicity 3 or greater is predicted. The possible use of the LSD to search for nucleon instability (proton decay into muons) is considered.

  15. Characterization of liquid scintillation detector (BC-501A) and digital pulse shape discrimination (DPSD) system

    SciTech Connect

    Lombigit, L. Yussup, N. Ibrahim, Maslina Mohd; Rahman, Nur Aira Abd; Rawi, M. Z. M.

    2015-04-29

    A digital n/γ pulse shape discrimination (PSD) system is currently under development at Instrumentation and Automation Centre, Malaysian Nuclear Agency. This system aims at simultaneous detection of fast neutron and gamma ray in mixed radiations environment. This work reports the system characterization performed on the liquid scintillation detector (BC-501A) and digital pulse shape discrimination (DPSD) system. The characterization involves measurement of electron light output from the BC-501A detector and energy channels calibration of the pulse height spectra acquired with DPSD system using set of photon reference sources. The main goal of this experiment is to calibrate the ADC channel of our DPSD system, characterized the BC-501 detector and find the position of Compton edge which later could be used as threshold for the n/γ PSD experiment. The detector resolution however is worse as compared to other published data but it is expected as our detector has a smaller active volume.

  16. Characterization of a 10B-doped liquid scintillator as a capture-gated neutron spectrometer

    NASA Astrophysics Data System (ADS)

    Hunt, S.; Iliadis, C.; Longland, R.

    2016-03-01

    We use a 250 MHz digitizer to characterize the pulse shape discrimination of a BC-523A 10B-doped liquid scintillator with capture-gating capabilities. Our results are compared to recent work claiming pulse shape discrimination between fast and thermal neutron signals. The capture event is identified, and we explain the origin of signals that are often misinterpreted. We use the time-of-flight method to measure the detector energy resolution for fast incident monoenergetic neutrons and the intrinsic neutron detection efficiency. Monte Carlo simulations are performed and we find agreement between measured and simulated results. These steps are important for understanding 10B-doped capture-gated spectroscopy in mixed radiation environments, as efficiencies using capture-gating are rarely reported in the literature.

  17. Unfolding the fast neutron spectra of a BC501A liquid scintillation detector using GRAVEL method

    NASA Astrophysics Data System (ADS)

    Chen, YongHao; Chen, XiMeng; Lei, JiaRong; An, Li; Zhang, XiaoDong; Shao, JianXiong; Zheng, Pu; Wang, XinHua

    2014-10-01

    Accurate knowledge of the neutron energy spectra is useful in basic research and applications. The overall procedure of measuring and unfolding the fast neutron energy spectra with BC501A liquid scintillation detector is described. The recoil proton spectrum of 241Am-Be neutrons was obtained experimentally. With the NRESP7 code, the response matrix of detector was simulated. Combining the recoil proton spectrum and response matrix, the unfolding of neutron spectra was performed by GRAVEL iterative algorithm. A MatLab program based on the GRAVEL method was developed. The continuous neutron spectrum of 241Am-Be source and monoenergetic neutron spectrum of D-T source have been unfolded successfully and are in good agreement with their standard reference spectra. The unfolded 241Am-Be spectrum are more accurate than the spectra unfolded by artificial neural networks in recent years.

  18. Development and Characterization of 6Li-doped Liquid Scintillator Detectors for PROSPECT

    NASA Astrophysics Data System (ADS)

    Gaison, Jeremy; Prospect Collaboration

    2016-09-01

    PROSPECT, the Precision Reactor Oscillation and Spectrum experiment, is a phased reactor antineutrino experiment designed to search for eV-scale sterile neutrinos via short-baseline neutrino oscillations and to make a precision measurement of the 235U reactor antineutrino spectrum. A multi-ton, optically segmented detector will be deployed at Oak Ridge National Laboratory's (ORNL) High Flux Isotope Reactor (HFIR) to measure the reactor spectrum at baselines ranging from 7-12m. A two-segment detector prototype with 50 liters of active liquid scintillator target has been built to verify the detector design and to benchmark its performance. In this presentation, we will summarize the performance of this detector prototype and describe the optical and energy calibration of the segmented PROSPECT detectors.

  19. Study on Response Function of Organic Liquid Scintillator for High-Energy Neutrons

    NASA Astrophysics Data System (ADS)

    Satoh, Daiki; Sato, Tatsuhiko; Endo, Akira; Yamaguchi, Yasuhiro; Takada, Masashi; Ishibashi, Kenji

    2005-05-01

    Response functions of liquid organic scintillator for neutrons up to 800 MeV have been measured at the Heavy-Ion Medical Accelerator in Chiba (HIMAC) of National Institute of Radiological Sciences (NIRS). 800-MeV/u Si ions and 400-MeV/u C ions bombarded a thick carbon target to produce neutrons. The kinetic energies of emitted neutrons were determined by the time-of-flight (TOF) method. Light output for neutrons was evaluated by eliminating events due to gamma-rays and charged particles. The measured response functions were compared with calculations using SCINFUL-QMD and CECIL codes. It was found that SCINFUL-QMD reproduced our experimental data adequately.

  20. Laboratory measurement of radioactivity purification for 212Pb in liquid scintillator

    NASA Astrophysics Data System (ADS)

    Hu, Wei; Fang, Jian; Yu, Bo-Xiang; Zhang, Xuan; Zhou, Li; Cai, Xiao; Sun, Li-Jun; Liu, Wan-Jin; Wang, Lan; Lü, Jun-Guang

    2016-09-01

    Liquid scintillator (LS) has been widely used in past and running neutrino experiments, and is expected also to be used in future experiments. Requirements on LS radio-purity have become higher and higher. Water extraction is a powerful method to remove soluble radioactive nuclei, and a mini-extraction station has been constructed. To evaluate the extraction efficiency and optimize the operation parameters, a setup to load radioactivity to LS and a laboratory scale setup to measure radioactivity using the 212Bi-212Po-208Pb cascade decay have been developed. Experience from this laboratory study will be useful for the design of large scale water extraction plants and the optimization of working conditions in the future. Supported by The Strategic Priority Research Program of the Chinese Academy of Sciences (XDA10010500), Natural Science Foundation of China (11390384)

  1. Analysis of 161Tb by radiochemical separation and liquid scintillation counting

    SciTech Connect

    Jiang, J.; Davies, A.; Arrigo, L.; Friese, J.; Seiner, B. N.; Greenwood, L.; Finch, Z.

    2015-12-05

    The determination of 161Tb activity is problematic due to its very low fission yield, short half-life, and the complication of its gamma spectrum. At AWE, radiochemically purified 161Tb solution was measured on a PerkinElmer 1220 QuantulusTM Liquid Scintillation Spectrometer. Since there was no 161Tb certified standard solution available commercially, the counting efficiency was determined by the CIEMAT/NIST Efficiency Tracing method. The method was validated during a recent inter-laboratory comparison exercise involving the analysis of a uranium sample irradiated with thermal neutrons. Lastly, the measured 161Tb result was in excellent agreement with the result using gamma spectrometry and the result obtained by Pacific Northwest National Laboratory.

  2. Analysis of 161Tb by radiochemical separation and liquid scintillation counting

    DOE PAGES

    Jiang, J.; Davies, A.; Arrigo, L.; ...

    2015-12-05

    The determination of 161Tb activity is problematic due to its very low fission yield, short half-life, and the complication of its gamma spectrum. At AWE, radiochemically purified 161Tb solution was measured on a PerkinElmer 1220 QuantulusTM Liquid Scintillation Spectrometer. Since there was no 161Tb certified standard solution available commercially, the counting efficiency was determined by the CIEMAT/NIST Efficiency Tracing method. The method was validated during a recent inter-laboratory comparison exercise involving the analysis of a uranium sample irradiated with thermal neutrons. Lastly, the measured 161Tb result was in excellent agreement with the result using gamma spectrometry and the result obtainedmore » by Pacific Northwest National Laboratory.« less

  3. Determination of (226)Ra in produced water by liquid scintillation counting.

    PubMed

    Godoy, José Marcus; Vianna, Lucas M; Godoy, Maria Luiza D P; Almeida, Ana Cristina

    2016-08-01

    It is proposed a method for the determination of (226)Ra in offshore platform liquid effluent samples (produced water). The method is based on a two-phase liquid scintillation counting system and allows for the direct and simple determination of (226)Ra content. Samples with high barium content may also have high (226)Ra concentration. Therefore, the sample volume is based on the barium concentration and ranges from 10 mL to 100 mL. Our new method was tested using multiple real samples and was compared with the BaSO4 precipitation method. The results based on the LSC were 30% higher than the precipitation method, which is attributed to the self-absorption of alpha particles in the BaSO4 precipitate. The determination of both (226)Ra and (228)Ra in the liquid effluent of offshore oil platforms is mandatory in Brazil. Thus, a second method of accurately assessing (228)Ra content remains necessary. Copyright © 2016. Published by Elsevier Ltd.

  4. COCO, a Compton coincidence experiment to study liquid scintillator response in the 1-20 keV energy range

    NASA Astrophysics Data System (ADS)

    Péron, M. N.; Cassette, P.

    1994-12-01

    The use of Liquid Scintillation Counting (LSC) as a fundamental radionuclide standardisation method requires a correct description of the physical phenomena occurring during the LSC process. In that framework, a special point of interest is the description of the liquid scintillator response, especially for low-energy electrons, in a region where this response is known to be non-linear. As there is no simple way to produce monoenergetic electrons in the liquid scintillator, we have simulated these electrons using a Compton interaction coincidence method. Due to the energy conservation law, the selection of the energy of the scattered Compton X-ray photon is equivalent to the selection of the energy of a monoenergetic electron. This paper describes the experimental system and the methods used to analyse the experimental results in order to deduce the statistical distribution of the photons emitted by the scintillator. The effects of some artefacts are discussed, including the accidental coincidences and the influence of cascade Compton interactions.

  5. Exploration of the potential of liquid scintillators for real-time 3D dosimetry of intensity modulated proton beams

    PubMed Central

    Beddar, Sam; Archambault, Louis; Sahoo, Narayan; Poenisch, Falk; Chen, George T.; Gillin, Michael T.; Mohan, Radhe

    2009-01-01

    In this study, the authors investigated the feasibility of using a 3D liquid scintillator (LS) detector system for the verification and characterization of proton beams in real time for intensity and energy-modulated proton therapy. A plastic tank filled with liquid scintillator was irradiated with pristine proton Bragg peaks. Scintillation light produced during the irradiation was measured with a CCD camera. Acquisition rates of 20 and 10 frames per second (fps) were used to image consecutive frame sequences. These measurements were then compared to ion chamber measurements and Monte Carlo simulations. The light distribution measured from the images acquired at rates of 20 and 10 fps have standard deviations of 1.1% and 0.7%, respectively, in the plateau region of the Bragg curve. Differences were seen between the raw LS signal and the ion chamber due to the quenching effects of the LS and due to the optical properties of the imaging system. The authors showed that this effect can be accounted for and corrected by Monte Carlo simulations. The liquid scintillator detector system has a good potential for performing fast proton beam verification and characterization. PMID:19544791

  6. XENON100 Dark Matter Search: Scintillation Response of Liquid Xenon to Electronic Recoils

    NASA Astrophysics Data System (ADS)

    Lim, Kyungeun Elizabeth

    Dark matter is one of the missing pieces necessary to complete the puzzle of the universe. Numerous astrophysical observations at all scales suggest that 23 % of the universe is made of nonluminous, cold, collisionless, nonbaryonic, yet undiscovered dark matter. Weakly Interacting Massive Particles (WIMPs) are the most well-motivated dark matter candidates and significant efforts have been made to search for WIMPs. The XENON100 dark matter experiment is currently the most sensitive experiment in the global race for the first direct detection of WIMP dark matter. XENON100 is a dual-phase (liquid-gas) time projection chamber containing a total of 161 kg of liquid xenon (LXe) with a 62kg WIMP target mass. It has been built with radiopure materials to achieve an ultra-low electromagnetic background and operated at the Laboratori Nazionali del Gran Sasso in Italy. WIMPs are expected to scatter off xenon nuclei in the target volume. Simultaneous measurement of ionization and scintillation produced by nuclear recoils allows for the detection of WIMPs in XENON100. Data from the XENON100 experiment have resulted in the most stringent limits on the spin-independent elastic WIMP-nucleon scattering cross sections for most of the significant WIMP masses. As the experimental precision increases, a better understanding of the scintillation and ionization response of LXe to low energy (< 10 keV) particles is crucial for the interpretation of data from LXe based WIMP searches. A setup has been built and operated at Columbia University to measure the scintillation response of LXe to both electronic and nuclear recoils down to energies of a few keV, in particular for the XENON100 experiment. In this thesis, I present the research carried out in the context of the XENON100 dark matter search experiment. For the theoretical foundation of the XENON100 experiment, the first two chapters are dedicated to the motivation for and detection medium choice of the XENON100 experiment

  7. Effects of sampling technique, storage, cocktails, sources of variation, and extraction on the liquid scintillation technique for radon in water

    SciTech Connect

    Kinner, N.E.; Malley, J.P. Jr.; Clement, J.A.; Quern, P.A.; Schell, G.S.; Lessard, C.E. )

    1991-06-01

    Sampling and analytical procedures used in the liquid scintillation counting technique to determine radon in water were examined in a series of experiments. Factors evaluated included the following: sample collection, length of storage, sources of variability, choice of scintillation cocktail, and extraction procedure. Collection using the direct syringe technique yielded the highest radon activities, but its widespread use may be limited by cost and problems with distribution of syringes. Storage in VOA bottles was primarily affected by radioactive decay; however, leakage also led to decreases in radon activity. Sample preparation and instrumentation caused the majority of the variability observed in this study. An Opti-Fluor O scintillation cocktail yielded significantly higher count rates and was less expensive than toluene and mineral oil based cocktails. The data suggested that while the extraction procedure should not be considered in calculating the efficiency factor, samples should be shaken to maximize the rate of transfer of radon to the cocktail phase.

  8. Patient-specific quality assurance for spot scanning proton beams using a large-volume liquid scintillator detector

    NASA Astrophysics Data System (ADS)

    Robertson, D.; Beddar, S.

    2017-05-01

    A large-volume liquid scintillator detector was used to measure individual energy layers from a clinical prostate treatment plan on a scanning proton beam system. Lateral and beam’s-eye view images of the dose distribution were acquired with two CCD cameras facing adjacent sides of a scintillator tank. The measured dose images were compared with calculated dose distributions from a validated Monte Carlo model. The measured and calculated dose distributions showed good agreement, with the exception of the Bragg peak region of the lateral view, which exhibited ionization quenching. The beam’s-eye and lateral views achieved gamma analysis passing rates of 99.7% and 92.5%, respectively, using gamma criteria of 3%, 3 mm. Large-volume scintillator detectors show promise for quick and accurate measurements of patient treatment fields for scanning proton beam systems.

  9. Review of plastic and liquid scintillation dosimetry for photon, electron, and proton therapy

    NASA Astrophysics Data System (ADS)

    Beaulieu, Luc; Beddar, Sam

    2016-10-01

    While scintillation dosimetry has been around for decades, the need for a dosimeter tailored to the reality of modern radiation therapy—in particular a real-time, water-equivalent, energy-independent dosimeter with high spatial resolution—has generated renewed interest in scintillators over the last 10 years. With the advent of at least one commercial plastic scintillation dosimeter and the ever-growing scientific literature on this subject, this topical review is intended to provide the medical physics community with a wide overview of scintillation physics, related optical concepts, and applications of plastic scintillation dosimetry.

  10. Characterizing a fast-response, low-afterglow liquid scintillator for neutron time-of-flight diagnostics in fast ignition experiments

    SciTech Connect

    Abe, Y. Hosoda, H.; Arikawa, Y.; Nagai, T.; Kojima, S.; Sakata, S.; Inoue, H.; Iwasa, Y.; Iwano, K.; Yamanoi, K.; Fujioka, S.; Nakai, M.; Sarukura, N.; Shiraga, H.; Norimatsu, T.; Azechi, H.

    2014-11-15

    The characteristics of oxygen-enriched liquid scintillators with very low afterglow are investigated and optimized for application to a single-hit neutron spectrometer for fast ignition experiments. It is found that 1,2,4-trimethylbenzene has better characteristics as a liquid scintillator solvent than the conventional solvent, p-xylene. In addition, a benzophenon-doped BBQ liquid scintillator is shown to demonstrate very rapid time response, and therefore has potential for further use in neutron diagnostics with fast time resolution.

  11. SOLVENT PURIFICATION AND FLUOR SELECTION FOR GADOLINIUM-LOADED LIQUID SCINTILLATORS

    SciTech Connect

    Kesete, T.; Storm, A.; Hahn, R. L.; Yeh, M.; Seleem, S.

    2007-01-01

    The last decade has seen huge progress in the study of neutrinos, elementary sub-atomic particles. Continued growth in the fi eld of neutrino research depends strongly on the calculation of the neutrino mixing angle θ13, a fundamental neutrino parameter that is needed as an indicative guideline for proposed next-generation neutrino experiments. Experiments involving reactor antineutrinos are favored for the calculation of θ13 because their derivation equation for θ13 is relatively simple and unambiguous. A Gd-loaded liquid scintillator (Gd-LS) is the centerpiece of the detector and it consists of ~99% aromatic solvent, ~0.1% Gd, and < 1% fl uors. Key required characteristics of the Gd-LS are long-term chemical stability, high optical transparency, and high photon production by the scintillator. This summer’s research focused on two important aspects of the detector: (1) purifi cation of two selected scintillation solvents, 1, 2, 4-trimethylbenzene (PC) and linear alkyl benzene (LAB), to improve the optical transparency and long-term chemical stability of the Gd-LS, and (2) investigation of the added fl uors to optimize the photon production. Vacuum distillation and column separation were used to purify PC and LAB, respectively. Purifi cation was monitored using UV-visible absorption spectra and verifi ed in terms of decreased solvent absorption at 430nm. Absorption in PC at 430nm decreased by a factor slightly >10 while the absorption in LAB was lowered by a factor of ~5. Photon production for every possible combination of two solvents, four primary shifters, and two secondary shifters was determined by measuring the Compton-Scattering excitation induced by an external Cs-137 gamma source (Eγ ~ 662-keV). The ideal shifter concentration was identifi ed by measuring the photon production as a function of shifter quantity in a series of samples. Results indicate that 6g/L p-terphenyl with 150mg/L 1,4-Bis(2-methylstyryl)-benzene (bis-MSB) produces the maximum

  12. Relative scintillation efficiency of liquid xenon in the XENON10 direct dark matter search

    NASA Astrophysics Data System (ADS)

    Manzur, Angel

    There is almost universal agreement that most of the mass in the Universe consists of dark matter. Many lines of reasoning suggest that the dark matter consists of a weakly interactive massive particle (WIMP) with mass ranging from 10 GeV/c 2 to a few TeV/c 2 . Today, numerous experiments aim for direct or indirect dark matter detection. XENON10 is a direct detection experiment using a xenon dual phase time projection chamber. Particles interacting with xenon will create a scintillation signal ( S 1) and ionization. The charge produced is extracted into the gas phase and converted into a proportional scintillation light ( S 2), with an external electric field. The dominant background, b particles and g rays, will undergo an electron recoil (ER) interaction, while WIMPs and neutrons will undergo a nuclear recoil (NR) interaction. Event-by-event discrimination of background signals is based on log 10 ( S 2/ S 1) NR < log 10 ( S 2/ S 1) ER and the 3-D position reconstruction. In 2006 the XENON10 detector started underground operations at laboratorio Nazionali del Gran Sasso in Italy. After 6 months of operations, totaling 58.6 live days and 5.4 kg of fiducial mass, XENON10 set the best upper limits at the time. Finding a spin- independent WIMP-nucleon cross-section s h = 8.8 × 10^-44 cm 2 and a spin- dependent WIMP-neutron cross-section s h = 1.0 × 10^-38 cm 2 for a WIMP mass of 100 GeV/c 2 (90% C.L.). In this work I give an overview of the dark matter evidence and review the requirements for a dark matter search. In particular I discuss the XENON10 detector, deployment, operation, calibrations, analysis and WIMP-nucleon cross- section limits. Finally, I present our latest results for the relative scintillation efficiency ([Special characters omitted.] ) for nuclear recoils in liquid xenon, which was the biggest source of uncertainty in the XENON10 limit. This quantity is essential to determine the nuclear energy scale and to determine the WIMP-nucleon cross

  13. Liquid scintillation counting methodology for 99Tc analysis. A remedy for radiopharmaceutical waste

    SciTech Connect

    Khan, Mumtaz; Um, Wooyong

    2015-08-13

    This paper presents a new approach for liquid scintillation counting (LSC) analysis of single-radionuclide samples containing appreciable organic or inorganic quench. This work offers better analytical results than existing LSC methods for technetium-99 (99gTc) analysis with significant savings in analysis cost and time. The method was developed to quantify 99gTc in environmental liquid and urine samples using LSC. Method efficiency was measured in the presence of 1.9 to 11,900 ppm total dissolved solids. The quench curve was proved to be effective in the case of spiked 99gTc activity calculation for deionized water, tap water, groundwater, seawater, and urine samples. Counting efficiency was found to be 91.66% for Ultima Gold LLT (ULG-LLT) and Ultima Gold (ULG). Relative error in spiked 99gTc samples was ±3.98% in ULG and ULG-LLT cocktails. Minimum detectable activity was determined to be 25.3 mBq and 22.7 mBq for ULG-LLT and ULG cocktails, respectively. A pre-concentration factor of 1000 was achieved at 100°C for 100% chemical recovery.

  14. Liquid scintillation counting methodology for (99)Tc analysis: a remedy for radiopharmaceutical waste.

    PubMed

    Khan, Mumtaz; Um, Wooyong

    2015-09-01

    This paper presents a new approach for liquid scintillation counting (LSC) analysis of single-radionuclide samples containing appreciable organic or inorganic quench. This work offers better analytical results than existing LSC methods for technetium-99 ((99g)Tc) analysis with significant savings in analysis cost and time. The method was developed to quantify (99g)Tc in environmental liquid and urine samples using LSC. Method efficiency was measured in the presence of 1.9 to 11 900 ppm total dissolved solids. The resultant quench curve proved to be effective for quantifying spiked (99g)Tc activity in deionized water, tap water, groundwater, seawater, and urine samples. Counting efficiency was found to be 91.66% for Ultima Gold LLT (ULG-LLT) and Ultima Gold (ULG). Relative error in spiked (99g)Tc samples was ±3.98% in ULG and ULG-LLT cocktails. Minimum detectable activity was determined to be 25.3 and 22.7 mBq for ULG-LLT and ULG cocktails, respectively. A preconcentration factor of 1000 was achieved at 100 °C for 100% chemical recovery.

  15. Hybrid Light Imaging Using Cerenkov Luminescence and Liquid Scintillation for Preclinical Optical Imaging In Vivo.

    PubMed

    Shimamoto, Masako; Gotoh, Kumiko; Hasegawa, Koki; Kojima, Akihiro

    2016-08-01

    Cerenkov luminescence imaging (CLI) has recently emerged as a molecular imaging modality for radionuclides emitting β-particles. The aim of this study was to develop a hybrid light imaging (HLI) technique using a liquid scintillator to assist CLI by increasing the optical signal intensity from both β-particle and γ-ray emitting radionuclides located at deep regions in vivo. A commercial optical imaging system was employed to collect all images by HLI and CLI. To investigate the performance characteristics of HLI with a commercially available liquid scintillator (Emulsifier-safe), phantom experiments were conducted for two typical β-particle and γ-ray emitters, sodium iodide (Na[(131)I]I) and 2-deoxy-2-[(18)F]fluoro-D-glucose ([(18)F]FDG), respectively. To evaluate the feasibility of HLI for in vivo imaging, HLI was applied to a Na[(131)I]I injected nu/nu mouse and an [(18)F]FDG injected Balb-c mouse and compared with CLI alone. Measured HLI wavelength spectra with Emulsifier-safe showed higher signal intensities than for CLI at 500-600 nm. For material preventing light transmission of 12-mm thickness, CLI imaging provided quite low intensity and obscure signals of the source. However, despite degraded spatial resolution, HLI imaging provided sustained visualization of the source shape, with signal intensities 10-14 times higher than for CLI at 10-mm thickness. Furthermore, at 0, 4, and 8-mm material thicknesses, HLI showed a strong correlation between Na[(131)I]I or [(18)F]FDG radioactivity and signal intensity, as for CLI. In vivo studies also demonstrated that HLI could successfully visualize Na[(131)I]I uptake in the mouse thyroid gland in the prone position and [(18)F]FDG accumulation in the heart in the supine position, which were not observed with CLI. Our preliminary studies suggest that HLI can provide enhanced imaging of a β-particle probe emitting together with γ-rays at deep tissue locations. HLI may be a promising imaging technique to assist

  16. Updated results from the 3-ton Gd loaded liquid scintillator target after 2 years of data taking at LNGS

    NASA Astrophysics Data System (ADS)

    Barabanov, I.; Cattadori, C.; Danilov, N.; di Vacri, A.; Ioannucci, L.; Krilov, Y.; Yanovich, E.; Aglietta, M.; Bari, G.; Bonardi, A.; Bruno, G.; Fulgione, W.; Kemp, E.; Malguine, A.; Porta, A.; LVD Collaboration

    2008-07-01

    We performed a 3-m3 Gd experiment by doping (up to 0.1% in weight) two counters of the LVD experiment, at LNGS, with a Gd organic salt developed and produced as the result of a joint INFN/INR research activity. Feasibility of the experiment and performances of the Gd doped liquid scintillator (Gd-LS) have been presented. The chemical and physical properties of the Gd-LS and its performance as a neutron detector, namely neutron capture efficiency and average capture time are being monitored since the doping time in 2005. From laboratory survey we can state the stability of the trasmittance (T) at the reference wavelength (425 nm) with a C.L. of 81% and 96% respectively for the first and the second doped counter. This is the largest stable Gd-doped organic liquid scintillator target ever produced and continuously operated for a long period.

  17. Application of a BC501A Liquid Scintillation Detector with a Gain Stabilization System on the EAST Tokamak

    NASA Astrophysics Data System (ADS)

    Peng, Xingyu; Chen, Zhongjing; Du, Tengfei; Hu, Zhimeng; Ge, Lijian; Chen, Jinxiang; Li, Xiangqing; Fan, Tieshuan

    2016-01-01

    A 2” × 2” BC501A liquid scintillation detector with a gain stabilization system is developed and applied to neutron and γ-ray measurement on the EAST tokamak. Energy calibration of a liquid scintillator using a fast coincidence method is presented and compared with the Monte Carlo simulation. Determination of the proton light output function of the BC501A is presented. Results from dedicated experiments with an Am-Be neutron source, γ source and quasi-monoenergetic neutron beams, and from measurements on EAST tokamak are presented and discussed. supported by the National Magnetic Confinement Fusion Science Program of China (Nos. 2013GB106004 and 2012GB101003) and National Natural Science Foundation of China (No. 91226102)

  18. The angular dependence of pulse shape discrimination and detection sensitivity in cylindrical and cubic EJ-309 organic liquid scintillators

    NASA Astrophysics Data System (ADS)

    Jones, A. R.; Joyce, M. J.

    2017-01-01

    Liquid scintillators are used widely for neutron detection and for the assay of nuclear materials. However, due to the constituents of the detector and the nitrogen void within the detector cell, usually incorporated to accommodate any expansion that might occur to avoid leakage, fluctuations in detector response have been observed associated with the orientation of the detector when in use. In this work the angular dependence of the pulse-shape discrimination performance in an EJ309 liquid scintillator has been investigated with 252Cf in terms of the separation of γ -ray and neutron events, described quantitatively by the figure-of-merit. A subtle dependence in terms of pulse-shape discrimination is observed. In contrast, a more significant dependence of detection sensitivity with the angle of orientation is evident.

  19. Decoloration and solubilization of plant tissue prior to determination of 3H, 14C, and 35S by liquid scintillation.

    PubMed

    Smith, I K; Lang, A L

    1987-08-01

    A method is described for the decoloration and partial solubilization of plant tissue with 2% sodium hypochlorite. Following treatment of the digest with ammonia, the samples are suitable for the determination of 3H, 14C, and 35S by liquid scintillation counting. The color quenching is negligible and counting efficiencies are high: 30-40% for 3H and 90-95% for 14C.

  20. Establishment of a method for ²²²Rn determination in water by low-level liquid scintillation counter.

    PubMed

    Todorović, Nataša; Jakonić, Ivana; Nikolov, Jovana; Hansman, Jan; Vesković, Miroslav

    2014-11-01

    A procedure for the determination of (222)Rn in environmental water samples using liquid scintillation counting (LSC) was performed. The (226)Ra content in the water was determined by gamma-ray spectroscopy. An application of this procedure to drinking water collected from a public drinking fountain in Vojvodina (Serbia) is presented, including calculations of the annual effective dose for ingestion and inhalation for adults.

  1. Liquid scintillation counting of /sup 14/C for differentiation of synthetic ethanol from ethanol of fermentation

    SciTech Connect

    Martin, G.E.; Noakes, J.E.; Alfonso, F.C.; Figert, D.M.

    1981-09-01

    Samples containing ethanol are fractionated on a column so that the resultant ethanol content is > 93%. Determination of /sup 14/C by liquid scintillation counting on the ethanol fraction differentiates ethanol produced by fermentation from synthetic ethanol produced from fossil fuel sources. Twenty-seven samples were fractionated and analyzed for the /sup 14/C isotope. Six samples were synthetic ethanol derived from ethylene gas (direct and indirect process), and yielded a mean value for /sup 14/C isotope of 0.167 dpm/g carbon with a standard deviation (SD) of 0.066 dpm/g carbon (disintegrations per minute per gram of carbon). The remaining samples were ethanol derived from the fermentation of natural materials, such as corn, pear, sugar cane, grape, cherry, and blackberry, and yielded a mean value for /sup 14/C isotope of 16.11 dpm/g carbon with an SD of 1.27. The /sup 14/C values for specific mixtures of a synthetic and a natural ethanol compare favorably with the analytical values obtained by this procedure.

  2. Liquid Scintillation Counting of Environmental Radioisotopes: A Review of the Impact of Background Reduction

    SciTech Connect

    Douglas, Matthew; Bernacki, Bruce E.; Erchinger, Jennifer L.; Finn, Erin C.; Fuller, Erin S.; Hoppe, Eric W.; Keillor, Martin E.; Morley, Shannon M.; Mullen, Crystal A.; Orrell, John L.; Panisko, Mark E.; Warren, Glen A.; Wright, Michael E.

    2016-03-09

    Liquid scintillation counting (LSC) is a versatile and commonplace method for radiometric measurement of charged particle emitting radionuclides. The LSC method provides utility in a range of environmental science applications including hydrological studies of water transport, anthropogenic releases of radionuclides into the environment, and vertical mixing rates within oceans. Instrumental measurement background is one limiting factor of radiometric measurement sensitivity. As part of the development of a custom low background LSC system located in a shallow underground laboratory at Pacific Northwest National Laboratory, a number of measurement applications of LSC have been considered and are summarized here. The focus is on determining which aspects of such measurements would gain the greatest benefit from the reduction of LSC backgrounds by a factor of 10-100 relative to values reported in the literature. Examples of benefits include lowering the minimum detectable activity, reducing the sample size required, and shortening the elapsed timeline of the processing and analysis sequence. In particular tritium, strontium, and actinium isotopes are examined as these isotopes cover a range of requirements related to the LSC measurement method (e.g., 3H: low energy; Sr: spectral deconvolution; Ac: alpha/beta discrimination).

  3. Indium-loaded Liquid Scintillator for the Low Energy Neutrino Spectrometer (LENS)

    NASA Astrophysics Data System (ADS)

    Hu, Liangming; Hans, Sunej; Rosero, Richard; Beriguete, Wanda; Chan, Wai Ting; Cumming, James; Yeh, Minfang; Roundtree, Derek; Vogelaar, Bruce

    2012-03-01

    The Chemistry Department at Brookhaven National Laboratory has a long history of neutrino research since Ray Davis's Homestake experiment. The Solar Neutrino and Nuclear Chemistry group has been successfully building large neutrino detectors over the past decade for various physics experiments, using tens to hundreds of tons of liquid scintillator. Among them, LENS aims to use 8% indium-loaded LS (In-LS, first investigated by Raghavan in the 1970s) for a real-time measurement of over 95% of sub-MeV solar neutrinos, mainly from pp-, CNO-, and ^7Be-processes. A nearly background-free spectral image from neutrino interactions on ^115In can be obtained via a triple coincidence tag in space and time. LENS detector R&D has made major progress in the recent years. The development of In-LS, in collaboration with Virginia Tech, now meets the challenging requirements of light yield, optical clarity, and chemical stability; and the collaboration is in the process of building a 410-L prototype (miniLENS). In this talk, the preparation and properties of In-LS for the miniLENS detector will be presented.

  4. Development of a gadolinium-loaded liquid scintillator for the Hanaro short baseline prototype detector

    NASA Astrophysics Data System (ADS)

    Yeo, In Sung; Joo, Kyung Kwang; So, Sun Heang; Song, Sook Hyung; Kim, Hong Joo; So, Jung Ho; Park, Kang Soon; Ma, Kyung Ju; Jeon, Eun Ju; Kim, Jin Yu; Kim, Young Duk; Lee, Jason; Lee, Jeong-Yeon; Sun, Gwang-Min

    2014-02-01

    We propose a new experiment on the site of the Korea Atomic Energy Research Institute (KAERI) located at Daejeon, Korea. The Hanaro short baseline (SBL) nuclear reactor with a thermal power output 30 MW is used to investigate a reactor neutrino anomaly. A Hanaro SBL prototype detector having a 60- l volume has been constructed ˜6 m away from the reactor core. A gadolinium (Gd)-loaded liquid scintillator (LS) is used as an active material to trigger events. The selection of the LS is guided by physical and technical requirements, as well as safety considerations. A linear alkyl benzene (LAB) is used as a base solvent of the Hanaro SBL prototype detector. Three g/ l of PPO and 30 mg/ l of bis-MSB are dissolved to formulate the LAB-based LS. Then, a 0.5% gadolinium (Gd) complex with carboxylic acid is loaded into the LAB-based LS by using the liquidliquid extraction method. In this paper, we will summarize all the characteristics of the Gd-loaded LAB-based LS for the Hanaro prototype detector.

  5. Neutron light output response and resolution functions in EJ-309 liquid scintillation detectors

    SciTech Connect

    Enqvist, Andreas; Lawrence, Christopher C.; Wieger, Brian M.; Pozzi, Sara A.; Massey, Thomas N.

    2013-03-26

    Here, the neutron light output response functions and detector resolution functions were measured at Ohio University's tandem Van de Graaff generator for three cylindrical EJ-309 liquid scintillator cells, having dimensions 12.7(circle divide)-by-12.7, 7.6-by-7.6, and 7.6-by-5.1 cm. A 7.44 MeV deuteron beam was used on an Al-27 target generating a continuous spectrum over the energy range from a few hundred keV to over 10 MeV. The light output response functions are determined using an exponential fit. Detector resolution functions are obtained for the 12.7-by-12.7 and 7.6-by-7.6 cm detectors. It is demonstrated that the dependence on detector size is important for the light output response functions, but not to the same extent for the resolution function, even when photomultiplier tubes, detector material, and other detector characteristics are carefully matched.

  6. Discrimination of neutrons and γ-rays in liquid scintillator based on Elman neural network

    NASA Astrophysics Data System (ADS)

    Zhang, Cai-Xun; Lin, Shin-Ted; Zhao, Jian-Ling; Yu, Xun-Zhen; Wang, Li; Zhu, Jing-Jun; Xing, Hao-Yang

    2016-08-01

    In this work, a new neutron and γ (n/γ) discrimination method based on an Elman Neural Network (ENN) is proposed to improve the discrimination performance of liquid scintillator (LS) detectors. Neutron and γ data were acquired from an EJ-335 LS detector, which was exposed in a 241Am-9Be radiation field. Neutron and γ events were discriminated using two methods of artificial neural network including the ENN and a typical Back Propagation Neural Network (BPNN) as a control. The results show that the two methods have different n/γ discrimination performances. Compared to the BPNN, the ENN provides an improved of Figure of Merit (FOM) in n/γ discrimination. The FOM increases from 0.907 ± 0.034 to 0.953 ± 0.037 by using the new method of the ENN. The proposed n/γ discrimination method based on ENN provides a new choice of pulse shape discrimination in neutron detection. Supported by National Natural Science Foundation of China (11275134,11475117)

  7. Using the transportable, computer-operated, liquid-scintillator fast-neutron spectrometer system

    SciTech Connect

    Thorngate, J.H.

    1988-11-01

    When a detailed energy spectrum is needed for radiation-protection measurements from approximately 1 MeV up to several tens of MeV, organic-liquid scintillators make good neutron spectrometers. However, such a spectrometer requires a sophisticated electronics system and a computer to reduce the spectrum from the recorded data. Recently, we added a Nuclear Instrument Module (NIM) multichannel analyzer and a lap-top computer to the NIM electronics we have used for several years. The result is a transportable fast-neutron spectrometer system. The computer was programmed to guide the user through setting up the system, calibrating the spectrometer, measuring the spectrum, and reducing the data. Measurements can be made over three energy ranges, 0.6--2 MeV, 1.1--8 MeV, or 1.6--16 MeV, with the spectrum presented in 0.1-MeV increments. Results can be stored on a disk, presented in a table, and shown in graphical form. 5 refs., 51 figs.

  8. Measurement of the spectral fluence rate of reference neutron sources with a liquid scintillation detector.

    PubMed

    Zimbal, A

    2007-01-01

    Reference neutron sources such as (241)AmBe(alpha,n) and (252)Cf are commonly used to calibrate neutron detectors for radiation protection purposes. The calibration factors of these detectors depend on the spectral distribution of the neutron fluence from the source. Differences between the spectral fluence of the neutron source and the ISO-recommended reference spectra might be caused by the properties of the individual source. The spectral neutron fluence rates of different reference neutron sources used at PTB were measured with a liquid scintillation detector (NE213), using maximum entropy unfolding and a new, experimentally determined detector response matrix. The detector response matrix was determined by means of the time-of-flight technique at a pulsed neutron source with a broad energy distribution realised at the PTB accelerator facility. The results of the measurements of the reference sources are compared with the ISO-recommended reference spectra. For the PTB (241)AmBe(alpha,n) reference source, the spectral neutron fluence was determined by means of a high-resolution (3)He semiconductor sandwich spectrometer in 1982. These measurements were the basis for the ISO recommendations. The current measurements confirm the high-energy part (E(n) > 2 MeV) of this spectrum and demonstrate the suitability of this new method for high-resolution spectrometry of broad neutron spectra.

  9. Neutron light output response and resolution functions in EJ-309 liquid scintillation detectors

    DOE PAGES

    Enqvist, Andreas; Lawrence, Christopher C.; Wieger, Brian M.; ...

    2013-03-26

    Here, the neutron light output response functions and detector resolution functions were measured at Ohio University's tandem Van de Graaff generator for three cylindrical EJ-309 liquid scintillator cells, having dimensions 12.7(circle divide)-by-12.7, 7.6-by-7.6, and 7.6-by-5.1 cm. A 7.44 MeV deuteron beam was used on an Al-27 target generating a continuous spectrum over the energy range from a few hundred keV to over 10 MeV. The light output response functions are determined using an exponential fit. Detector resolution functions are obtained for the 12.7-by-12.7 and 7.6-by-7.6 cm detectors. It is demonstrated that the dependence on detector size is important for themore » light output response functions, but not to the same extent for the resolution function, even when photomultiplier tubes, detector material, and other detector characteristics are carefully matched.« less

  10. Discrete Wavelet Transform Method for High Flux n-γ Discrimination With Liquid Scintillators

    NASA Astrophysics Data System (ADS)

    Singh, Harleen; Mehra, Rohit

    2017-07-01

    A Novel method based on discrete wavelet transform (DWT) for n-γ discrimination in high radiation flux is presented. We investigated the behavior of higher order wavelets from different families such as the Daubechies family, symlets, and coiflet type wavelets for pulse shape discrimination. A DWT-based average pulse analysis of neutron and γ-ray pulses suggests less sensitivity of db2, db3, sym4, and coif1 wavelets over the widely used Haar wavelet and the charge comparison method for the pile-up events. The DWT method with proposed wavelets is applied to a mixed radiation field at an energy threshold of 500 keVee obtained from an americium-beryllium source exposed to BC501 liquid scintillator which was coupled to a 12-b digital oscilloscope with sampling rate of 2.5 GSamples/s. The proposed wavelets require a short processing gate and are more suitable when applied to high count rate measurement with large fraction of pile-up events in the data set. Furthermore, these wavelets are very stable toward the variation in the width of processing gate in DWT. This feature is very helpful in the optimization of processing gate for the real-time applications.

  11. An improved liquid scintillation counting method for the determination of gross alpha activity in groundwater wells.

    PubMed

    Ruberu, Shiyamalie R; Liu, Yun-Gang; Perera, S Kusum

    2008-10-01

    A liquid scintillation counting (LSC) method having several advantages over the gas proportional counting (GPC) U.S. Environmental Protection Agency (EPA) Method 900.0 for the detection of gross alpha activity in drinking water was evaluated in this study. The improved method described here involves the use of nitromethane as the quench agent for establishing counting efficiencies and spillover factors, and it minimizes sample preparation. It has the advantage of achieving the regulatory detection limit of 111 mBq L(-1) with short count times (100 min) and small sample aliquot sizes. A thorough method validation study was performed by testing field samples ranging in total dissolved solids (TDS) from 0.3 mg L(-1) to 1,000 mg L(-1) and spiking each matrix from 194 mBq L(-1) to 11.6 Bq L(-1). Comparable method precision and accuracy was observed on the two types of LSC instruments tested, Perkin Elmer Quantulus 1220 and Packard 2550, with the former giving better performance. Data presented demonstrate that this efficient and high throughput LSC method is suitable for groundwater samples in excess of 1,000 mg L(-1) of TDS in contrast with the 500 mg L(-1) limit by the routine GPC method. Groundwater wells across the state of California were sampled, analyzed for gross alpha activity using the EPA- approved method and the improved LSC method, and the results were compared.

  12. 210Pb and 210Po determination in environmental samples using liquid scintillation counting and alpha spectrometry

    NASA Astrophysics Data System (ADS)

    Pérez Sánchez, D.; Martin Sánchez, A.; Jurado Vargas, M.

    2003-01-01

    A simple radiochemical procedure has been developed to determine 210Pb and 210Po in environmental samples from the same matrix. Sediment samples are decomposed by leaching with mineral acids or by microwave digestion, while water samples are pre-concentrated. One part of the resulting solution, spiked with 209Po, is used for 210Po determination by spontaneous deposition onto nickel disks (α-spectrometry). The other part is assayed for 210Pb, separating the Pb either by anion-exchange (sediment samples), or by solvent extraction (water samples). The 210Pb source is finally prepared by precipitation as oxalate and the chemical recovery determined by gravimetry. The 210Pb activity concentration is determined by liquid scintillation. A standard sediment sample supplied by IAEA and spiked water samples were analysed to check the procedure. The 210Pb and 210Po measurements agreed well with the certifications, deviations being less than 10%. The mean recoveries for Pb and Po were (70±12)% and (77±8%) for sediments, and (70±10)% and (81±7)% for waters, respectively.

  13. ACID EVAPORATION OF ULTIMA GOLD TM AB LIQUID SCINTILLATION COCKTAIL RESIDUE

    SciTech Connect

    Kyser, E.; Fondeur, F.; Crump, S.

    2011-12-21

    Prior analyses of samples from the F/H Lab solutions showed the presence of diisopropylnapthalene (DIN), a major component of Ultima Gold{trademark} AB liquid scintillation cocktail (LSC). These solutions are processed through H-Canyon Tank 10.5 and ultimately through the 17.8E evaporator. Similar solutions originated in SRNL streams sent to the same H Canyon tanks. This study examined whether the presence of these organics poses a process-significant hazard for the evaporator. Evaporation and calorimetry testing of surrogate samples containing 2000 ppm of Ultima Gold{trademark} AB LSC in 8 M nitric acid have been completed. These experiments showed that although reactions between nitric acid and the organic components do occur, they do not appear to pose a significant hazard for runaway reactions or generation of energetic compounds in canyon evaporators. The amount of off-gas generated was relatively modest and appeared to be well within the venting capacity of the H-Canyon evaporators. A significant fraction of the organic components likely survives the evaporation process primarily as non-volatile components that are not expected to represent any new process concerns during downstream operations such as neutralization. Laboratory Waste solutions containing minor amounts of DIN can be safely received, stored, transferred, and processed through the canyon waste evaporator.

  14. An improved sensitive assay for polonium-210 by use of a background-rejecting extractive liquid-scintillation method.

    PubMed

    Case, G N; McDowell, W J

    1982-10-01

    A procedure is described for the determination of polonium-210 in various types of materials, including ores, mill tailings, and environmental samples, by a combined solvent-extraction liquid-scintillation spectrometry method. Concentration of polonium-210 and separation from interfering elements (such as iron) are accomplished by extraction from a 7M phosphoric acid-0.01M hydrochloric acid solution with 0.20M trioctylphosphine oxide solution (together with a scintillator) in toluene. The polonium-210 is determined by counting the 5.3-MeV alpha-radiation with a photon/ electron-rejecting alpha liquid-scintillation spectrometer. Extraction coefficients of over 1000 for polonium ensure quantitative recovery, and no other alpha-emitters in the decay chains of uranium-238, uranium-235 and thorium-232 are extracted. The results for several samples show the relative standard deviation to be approximately 1.2%. A lower limit of detection of 0.0038 pCi is proposed, based on a counting time of 1000 min and an easily obtainable background of 0.01 cpm for the alpha peak.

  15. Development of a liquid scintillator-based 3D detector for range measurements of spot-scanned proton beams

    NASA Astrophysics Data System (ADS)

    Darne, C. D.; Robertson, D.; Beddar, S.

    2017-05-01

    The goal of the present study is to develop a liquid scintillator-based 3D detector and investigate its performance for beam range measurements in real time. The detector design consists of a tank filled with water-equivalent liquid scintillator that scintillates in response to incident proton beams. Three scientific complementary metal-oxide semiconductor (sCMOS) cameras collect the resulting optical signals. Preliminary measurements have shown that the optical detection system can record light distribution profiles anywhere inside the tank with an average spatial resolution of 0.23 mm. By employing multiple cameras the system is capable of capturing high resolution 2D depth and beams-eye profiles of the delivered beam and can consequently localize the position of beam anywhere inside the tank. It is also shown that it is capable of accurately measuring proton beam range with no more than 0.3 mm difference from the nominal range. The detector system thus demonstrates its ability to perform fast, high-resolution, and precise beam range measurements in 3D.

  16. The light-yield response of a NE-213 liquid-scintillator detector measured using 2-6 MeV tagged neutrons

    NASA Astrophysics Data System (ADS)

    Scherzinger, J.; Al Jebali, R.; Annand, J. R. M.; Fissum, K. G.; Hall-Wilton, R.; Kanaki, K.; Lundin, M.; Nilsson, B.; Perrey, H.; Rosborg, A.; Svensson, H.

    2016-12-01

    The response of a NE-213 liquid-scintillator detector has been measured using tagged neutrons from 2 to 6 MeV originating from an Am/Be neutron source. The neutron energies were determined using the time-of-flight technique. Pulse-shape discrimination was employed to discern between gamma-rays and neutrons. The behavior of both the fast (35 ns) and the combined fast and slow (475 ns) components of the neutron scintillation-light pulses were studied. Three different prescriptions were used to relate the neutron maximum energy-transfer edges to the corresponding recoil-proton scintillation-light yields, and the results were compared to simulations. The overall normalizations of parametrizations which predict the fast or total light yield of the scintillation pulses were also tested. Our results agree with both existing data and existing parametrizations. We observe a clear sensitivity to the portion and length of the neutron scintillation-light pulse considered.

  17. Study of SiPM custom arrays for scintillation light detection in a Liquid Argon Time Projection Chamber

    NASA Astrophysics Data System (ADS)

    Cervi, T.; Babicz, M. E.; Bonesini, M.; Falcone, A.; Kose, U.; Nessi, M.; Menegolli, A.; Pietropaolo, F.; Raselli, G. L.; Rossella, M.; Torti, M.; Zani, A.

    2017-03-01

    Liquid Argon Time Projection Chamber (LAr-TPC) technique has been established as one of the most promising for the next generation of experiments dedicated to neutrino and rare-event physics. LAr-TPCs have the fundamental feature to be able to both collect the charge and the scintillation light produced after the passage of a ionizing particle inside the Argon volume. Scintillation light is traditionally detected by large surface Photo-Multiplier Tubes (PMTs) working at cryogenic temperature. Silicon Photo-Multipliers (SiPMs) are semiconductor-based devices with performances comparable to the PMT ones, but with very small active areas. For this reason we built a prototype array composed by SiPMs connected in different electrical configurations. We present results on preliminary tests made with four SiPMs, connected both in parallel and in series configurations, deployed into a 50 liters LAr-TPC exposed to cosmic rays at CERN.

  18. Light yield and n-γ pulse-shape discrimination of liquid scintillators based on linear alkyl benzene

    NASA Astrophysics Data System (ADS)

    Kögler, T.; Junghans, A. R.; Beyer, R.; Hannaske, R.; Massarczyk, R.; Schwengner, R.; Wagner, A.

    2012-03-01

    The relative light yields of NE-213 and LAB-based liquid scintillators to electrons were determined in the electron energy range 5-1600 keV using a combination of monoenergetic photon sources and a Compton spectrometer. The light yield was found to be proportional to energy for both types of scintillator and expected deviations below 100 keV were described successfully applying Birks' law. Digital pulse-shape discrimination in a mixed n-γ field of a 252Cf source was investigated for LAB+PPO and LAB+PPO+bis-MSB and compared to NE-213. In combination with these two solutes, LAB shows poorer abilities to separate neutron-induced pulses from photon-induced ones.

  19. Light yield and n-γ pulse-shape discrimination of liquid scintillators based on linear alkyl benzene

    NASA Astrophysics Data System (ADS)

    Kögler, T.; Beyer, R.; Birgersson, E.; Hannaske, R.; Junghans, A. R.; Massarczyk, R.; Matic, A.; Wagner, A.; Zuber, K.

    2013-02-01

    The relative light yields of NE-213 and linear alkyl benzene (LAB) based liquid scintillators from electrons were determined in the electron energy range 13-1600 keV using a combination of monoenergetic γ sources and a Compton spectrometer. The light yield was found to be proportional to energy for both types of scintillator and expected deviations below 100 keV were described successfully applying Birks’ law. A description of the Cherenkov light contribution to the total light yield was achieved for both detectors and is in agreement with the electromagnetic theory of fast particles in matter. Digital pulse-shape discrimination in a mixed n-γ field from a 252Cf source was investigated for LAB+PPO and LAB+PPO+bis-MSB and compared to NE-213. In combination with these two solutes, LAB shows poorer abilities to separate neutron-induced pulses from γ-induced ones.

  20. Determination of strontium-90 in deer bones by liquid scintillation spectrometry after separation on Sr-specific ion exchange columns.

    PubMed

    Landstetter, Claudia; Wallner, Gabriele

    2006-01-01

    The activity concentration of (90)Sr was determined in several deer bones from Austria. Strontium specific ion exchange columns with 4',4''(5'')-di-t-butylcyclohexane-18-crown-6 from Eichrom Industries, Inc. were used for separation. The yield of the chemical procedure was quantified with AAS. Directly after column separation, the solution containing (90)Sr was mixed with the scintillation cocktail HiSafe III and measured by liquid scintillation counting. Prevention of (210)Pb contamination and reusability of the separation columns was investigated as well as the activity distribution within the bones. Results were compared with pre-Chernobyl measurements in Austria; a correlation between activity concentration of (90)Sr and site altitude was found.

  1. The use of low-level liquid scintillation spectrometry for rapid measurement and decision making

    SciTech Connect

    Schoenhofer, F.

    1998-12-31

    Liquid scintillation spectrometry (LSC) has proved over the last fifteen years to be an excellent tool for low-level counting of beta- and alpha-particle emitters. Using low-level instruments the determination of, for instance {sup 90}Sr, could be considerably simplified in the laboratory, saving time and also money for chemicals and manpower. Furthermore, low-level instruments have been successfully used for measurements when fast analysis was required. The four instruments (Quantulus, Wallac Oy), that the author uses, have not only very low background, which cuts measurement time considerably; but from the pulse- height spectra much information about the nature of the radionuclides present and the absence of specific radionuclides can be extracted. From the absence of high-energy beta-particle activity in the pulse-height spectra of precipitation in the first days after the Chernobyl accident the author could draw the conclusion, that practically no {sup 90}Y was present and therefore only small amounts of {sup 90}Sr, if any, could be expected in precipitation and later in food. This enabled them to make the decision not to waste time with a large number of {sup 90}Sr analyses. Large numbers of drinking water samples could be screened for contamination much more sensitively and faster than by gamma-ray spectrometry. More examples will be presented of cases where rapid information was needed; how contamination and nuclear installations can be easily checked and how LSC helped to cut down the time required, the manpower and the costs for radon measurements and environmental surveillance.

  2. A Measurement of the Absorption of Liquid Argon Scintillation Light by Dissolved Nitrogen at the Part-Per-Million Level

    SciTech Connect

    Jones, B. J.P.; Chiu, C. S.; Conrad, J. M.; Ignarra, C. M.; Katori, T.; Toups, M.

    2013-07-24

    Here we report on a measurement of the absorption length of scintillation light in liquid argon due to dissolved nitrogen at the part-per-million (ppm)level. We inject controlled quantities of nitrogen into a high purity volume of liquid argon and monitor the light yield from an alpha source.The source is placed at different distances from a cryogenic photomultiplier tube assembly. By comparing the light yield from each position we extract the absorption cross section of nitrogen. We find that nitrogen absorbs argon scintillation light with strength of (1.51±0.15) × 10$-$4 cm$-$1ppm$-$1, correspondingto an absorption cross section of (4.99±0.51) × 10$-$21 cm2 molecule$-$1.We obtain the relationship between absorption length and nitrogenconcentration over the 0 to 50 ppm range and discuss the implicationsfor the design and data analysis of future large liquid argon time projection chamber (LArTPC)detectors. Our results indicate that for a current-generation LArTPC, wherea concentration of 2 parts per million of nitrogen is expected, the attenuationlength due to nitrogen will be 30±3 meters.

  3. Determination of 125I impurities in [ 123I]labelled radiopharmaceuticals, by liquid scintillation counting: sensitivity of the method

    NASA Astrophysics Data System (ADS)

    Bonardi, M. L.; Birattari, C.; Groppi, F.; Gini, L.; Mainardi, C. H. S.; Menapace, E.

    2004-01-01

    Iodine-125 is a radioisotopic impurity "always" present in iodine-123, produced by nuclear reactions induced either on natural or "highly" enriched targets. Liquid scintillation counting is a very sensitive tool to determine low level impurities of both low energy electrons and photons in aqueous and organic solutions of radiopharmaceutical compounds. With this technique it was possible to determine, on commercial samples, that the content of 125I was of the order of not less than 0.1% for 123I produced via 127I(p,5n) reactions and not less than 0.01% for 123I produced via "highly" enriched 124Xe(p,X) nuclear reactions.

  4. Results of low energy background measurements with the Liquid Scintillation Detector (LSD) of the Mont Blanc Laboratory

    NASA Technical Reports Server (NTRS)

    Aglietta, M.; Badino, G.; Bologna, G. F.; Castagnoli, C.; Fulgione, W.; Galeotti, P.; Saavedra, O.; Trinchero, G. C.; Vernetto, S.; Dadykin, V. L.

    1985-01-01

    The 90 tons liquid scintillation detector (LSD) is fully running since October 1984, at a depth of 5,200 hg/sq cm of standard rock underground. The main goal is to search for neutrino bursts from collapsing stars. The experiment is very sensitive to detect low energy particles and has a very good signature to gamma-rays from (n,p) reaction which follows the upsilon e + p yields n + e sup + neutrino capture. The analysis of data is presented and the preliminary results on low energy measurements are discussed.

  5. Radiocarbon dating of archaeological samples (sambaqui) using CO(2) absorption and liquid scintillation spectrometry of low background radiation.

    PubMed

    Mendonça, Maria Lúcia T G; Godoy, José M; da Cruz, Rosana P; Perez, Rhoneds A R

    2006-01-01

    Sambaqui means, in the Tupi language, a hill of shells. The sambaquis are archaeological sites with remains of pre-historical Brazilian occupation. Since the sambaqui sites in the Rio de Janeiro state region are older than 10,000 years, the applicability of CO(2) absorption on Carbo-sorb and (14)C determination by counting on a low background liquid scintillation counter was tested. In the present work, sambaqui shells were treated with H(3)PO(4) in a closed vessel in order to generate CO(2). The produced CO(2) was absorbed on Carbo-sorb. On saturation about 0.6g of carbon, as CO(2), was mixed with commercial liquid scintillation cocktail (Permafluor), and the (14)C activity determined by counting on a low background counter, Packard Tricarb 3170 TR/SL, for a period of 1000 mins to enable detection of a radiocarbon age of 22,400 BP. But only samples with ages up to 3500 BP were submitted to the method because the samples had been collected in the municipality of Guapimirim, in archaeological sambaqui-type sites belonging to this age range. The same samples were sent to the (14)C Laboratory of the Centro de Energia Nuclear na Agricultura (CENA/USP) where similar results were obtained.

  6. Homestake tracking spectrometer: a one-mile deep 1400-ton liquid-scintillation nucleon-decay detector

    SciTech Connect

    Cherry, M.L.; Davidson, I.; Lande, K.; Lee, C.K.; Marshall, E.; Steinberg, R.I.; Cleveland, B.; Davis, R. Jr.; Lowenstein, D.

    1982-01-01

    We describe a proposed nucleon decay detector able to demonstrate the existence of nucleon decay for lifetimes up to 5 x 10/sup 32/ yr. The proposed instrument is a self-vetoed completely-active 1400-ton liquid scintillation Tracking Spectrometer to be located in the Homestake Mine at a depth of 4200 mwe, where the cosmic ray muon flux is only 1100/m/sup 2//yr, more than 10/sup 7/ times lower than the flux at the earth's surface. Based on computer simulations and laboratory measurements, the Tracking Spectrometer will have a spatial resolution of +- 15 cm (0.32 radiation lengths); energy resolution of +- 4.2%; and time resolution of +-1.3 ns. Because liquid scintillator responds to total ionization energy, all neutrinoless nucleon decay modes will produce a sharp (+- 4.2%) total energy peak at approximately 938 MeV, thereby allowing clear separation of nucleon decay events from atmospheric neutrino and other backgrounds. The instrument will be about equally sensitive to most nucleon decay modes. It will be able to identify most of the likely decay modes (including n ..-->.. ..nu.. + K/sub s//sup 0/ as suggested by supersymmetric grand unified theories), as well as determine the charge of lepton secondaries and the polarization of secondary muons.

  7. Digital pulse shape discrimination methods for n-γ separation in an EJ-301 liquid scintillation detector

    NASA Astrophysics Data System (ADS)

    Wan, Bo; Zhang, Xue-Ying; Chen, Liang; Ge, Hong-Lin; Ma, Fei; Zhang, Hong-Bin; Ju, Yong-Qin; Zhang, Yan-Bin; Li, Yan-Yan; Xu, Xiao-Wei

    2015-11-01

    A digital pulse shape discrimination system based on a programmable module NI-5772 has been established and tested with an EJ-301 liquid scintillation detector. The module was operated by running programs developed in LabVIEW, with a sampling frequency up to 1.6 GS/s. Standard gamma sources 22Na, 137Cs and 60Co were used to calibrate the EJ-301 liquid scintillation detector, and the gamma response function was obtained. Digital algorithms for the charge comparison method and zero-crossing method have been developed. The experimental results show that both digital signal processing (DSP) algorithms can discriminate neutrons from γ-rays. Moreover, the zero-crossing method shows better n-γ discrimination at 80 keVee and lower, whereas the charge comparison method gives better results at higher thresholds. In addition, the figure-of-merit (FOM) for detectors of two different dimensions were extracted at 9 energy thresholds, and it was found that the smaller detector presented better n-γ separation for fission neutrons. Supported by National Natural Science Foundation of China (91226107, 11305229) and the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA03030300)

  8. Separating double-beta decay events from solar neutrino interactions in a kiloton-scale liquid scintillator detector by fast timing

    NASA Astrophysics Data System (ADS)

    Elagin, Andrey; Frisch, Henry J.; Naranjo, Brian; Ouellet, Jonathan; Winslow, Lindley; Wongjirad, Taritree

    2017-03-01

    We present a technique for separating nuclear double beta decay (ββ -decay) events from background neutrino interactions due to 8B decays in the sun. This background becomes dominant in a kiloton-scale liquid-scintillator detector deep underground and is usually considered as irreducible due to an overlap in deposited energy with the signal. However, electrons from 0 νββ -decay often exceed the Cherenkov threshold in liquid scintillator, producing photons that are prompt and correlated in direction with the initial electron direction. The use of large-area fast photodetectors allows some separation of these prompt photons from delayed isotropic scintillation light and, thus, the possibility of reconstructing the event topology. Using a simulation of a 6.5 m radius liquid scintillator detector with 100 ps resolution photodetectors, we show that a spherical harmonics analysis of early-arrival light can discriminate between 0 νββ -decay signal and 8B solar neutrino background events on a statistical basis. Good separation will require the development of a slow scintillator with a 5 ns risetime.

  9. Characteristic parameters in the measurement of (14)C of biobased diesel fuels by liquid scintillation.

    PubMed

    Idoeta, R; Pérez, E; Herranz, M; Legarda, F

    2014-11-01

    The direct method based on the radiocarbon content present in modern-day materials used for the quantification of the renewable origin component in diesel has been analysed in order to establish the best sample preparation and measuring conditions that minimise the limit of detection. The scintillation cocktail and the diesel/cocktail ratio have been optimised. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Separately measuring radon and thoron concentrations exhaled from soil using AlphaGUARD and liquid scintillation counter methods.

    PubMed

    Yasuoka, Y; Sorimachi, A; Ishikawa, T; Hosoda, M; Tokonami, S; Fukuhori, N; Janik, M

    2010-10-01

    It was shown that radon and thoron concentrations exhaled from soil were separately measured using the AlphaGUARD and liquid scintillation counter (LSC) methods. The thoron concentrations from the RAD 7 were used to create the conversion equation to calculate thoron levels with the AlphaGUARD. However, the conversion factor was found to depend on the air flow rate. When air containing thoron of ∼60 kBq m(-3) was fed to the scintillation cocktail, thoron and thoron progeny could not be measured with the LSC method. The radon concentration of about 10 kBq m(-3) was measured with three methods, first with the LSC method and then with two AlphaGUARDs (one in the diffusion mode and the other in the flow mode (0.5 l min(-1))). There were no significant differences between these results. Finally, it was shown that the radon and thoron concentrations in air could be measured with the AlphaGUARD and LSC methods.

  11. Liquid scintillation based quantitative measurement of dual radioisotopes (3H and 45Ca) in biological samples for bone remodeling studies.

    PubMed

    Hui, Susanta K; Sharma, M; Bhattacharyya, M H

    2012-01-01

    Acute and prolonged bone complications associated with radiation and chemotherapy in cancer survivors underscore the importance of establishing a laboratory-based complementary dual-isotope tool to evaluate short- as well as long-term bone remodeling in an in vivo model. To address this need, a liquid scintillation dual-label method was investigated using different scintillation cocktails for quantitative measurement of (3)H-tetracycline ((3)H-TC) and (45)Ca as markers of bone turnover in mice. Individual samples were prepared over a wide range of known (45)Ca/(3)H activity ratios. Results showed that (45)Ca/(3)H activity ratios determined experimentally by the dual-label method were comparable to the known activity ratios (percentage difference ∼2%), but large variations were found in samples with (45)Ca/(3)H activity ratios in range of 2-10 (percentage difference ∼20-30%). Urine and fecal samples from mice administered with both (3)H-TC and (45)Ca were analyzed with the dual-label method. Positive correlations between (3)H and (45)Ca in urine (R=0.93) and feces (R=0.83) indicate that (3)H-TC and (45)Ca can be interchangeably used to monitor longitudinal in vivo skeletal remodeling.

  12. DETECTORS AND EXPERIMENTAL METHODS: Measurement of the neutron spectrum of a Pu-C source with a liquid scintillator

    NASA Astrophysics Data System (ADS)

    Wang, Song-Lin; Huang, Han-Xiong; Ruan, Xi-Chao; Li, Xia; Bao, Jie; Nie, Yang-Bo; Zhong, Qi-Ping; Zhou, Zu-Ying; Kong, Xiang-Zhong

    2009-05-01

    The neutron response function for a BC501A liquid scintillator (LS) has been measured using a series of monoenergetic neutrons produced by the p-T reaction. The proton energies were chosen such as to produce neutrons in the energy range of 1 to 20 MeV. The principles of the technique of unfolding a neutron energy spectrum by using the measured neutron response function and the measured Pulse Height (PH) spectrum is briefly described. The PH spectrum of neutrons from the Pu-C source, which will be used for the calibration of the reactor antineutrino detectors for the Daya Bay neutrino experiment, was measured and analyzed to get the neutron energy spectrum. Simultaneously the neutron energy spectrum of an Am-Be source was measured and compared with other measurements as a check of the result for the Pu-C source. Finally, an error analysis and a discussion of the results are given.

  13. Luminescence and scintillation properties of liquid phase epitaxy grown Y2SiO5:Ce single crystalline films

    NASA Astrophysics Data System (ADS)

    Wantong, Kriangkrai; Yawai, Nattasuda; Chewpraditkul, Weerapong; Kucera, Miroslav; Hanus, Martin; Nikl, Martin

    2017-06-01

    Luminescence and scintillation properties of Y2SiO5:Ce single crystalline film (YSO:Ce-LPE) grown by the liquid phase epitaxy technique are investigated and compared to the bulk Czochralski-grown YSO:Ce single crystal (YSO:Ce-SC). The light yield (LY) and energy resolution are measured using an R6231 photomultiplier under excitation with α - and γ- rays. At 662 keV γ- rays, the LY value of 12,410 ph/MeV obtained for YSO:Ce -LPE is lower than that of 20,150 ph/MeV for YSO:Ce -SC whereas the comparable LY value and energy resolution are obtained under excitation with 5.5 MeV α- rays. The ratio of LY under excitation with α- and γ- rays (α/γ ratio) is determined. Dependence of LY on an amplifier shaping time (0.5-12 μs) is also measured.

  14. Absolute measurement of anti. nu. /sub p/ for /sup 252/Cf using the ORNL large liquid scintillator neutron detector

    SciTech Connect

    Spencer, R.R.; Gwin, R.; Ingle, R.

    1981-08-01

    The ORNL large liquid scintillator detector was used in a precise determination of anti ..nu../sub p/, the number of neutrons emitted promptly, for spontaneous fission of /sup 252/Cf. Measurements of the detector efficiency over a broad energy region were made by means of a proton-recoil technique employing the ORELA white neutron source. Monte Carlo calculation of the detector efficiency for a spectrum representative of /sup 252/Cf fission neutrons was calibrated with these elaborate measurements. The unusually flat response of the neutron detector resulted in elimination of several known sources of error. Experimental measurement was coupled with calculational methods to correct for other known errors. These measurements lead to an unusually small estimated uncertainty of 0.2% in the value obtained, anti ..nu../sub p/ = 3.773 +- 0.007.

  15. Attenuation length measurements of a liquid scintillator with LabVIEW and reliability evaluation of the device

    NASA Astrophysics Data System (ADS)

    Gao, Long; Yu, Bo-Xiang; Ding, Ya-Yun; Zhou, Li; Wen, Liang-Jian; Xie, Yu-Guang; Wang, Zhi-Gang; Cai, Xiao; Sun, Xi-Lei; Fang, Jian; Xue, Zhen; Zhang, Ai-Wu; Lü, Qi-Wen; Sun, Li-Jun; Ge, Yong-Shuai; Liu, Ying-Biao; Niu, Shun-Li; Hu, Tao; Cao, Jun; Lü, Jun-Guang

    2013-07-01

    An attenuation length measurement device was constructed using an oscilloscope and LabVIEW for signal acquisition and processing. The performance of the device has been tested in a variety of ways. The test results show that the set-up has a good stability and high precision (sigma/mean reached 0.4 percent). Besides, the accuracy of the measurement system will decrease by about 17 percent if a filter is used. The attenuation length of a gadolinium-loaded liquid scintillator (Gd-LS) was measured as 15.10±0.35 m where Gd-LS was heavily used in the Daya Bay Neutrino Experiment. In addition, one method based on the Beer-Lambert law was proposed to investigate the reliability of the measurement device, the R-square reached 0.9995. Moreover, three purification methods for Linear Alkyl Benzene (LAB) production were compared in the experiment.

  16. e+/e- discrimination in liquid scintillator and its usage to suppress 8He/9Li backgrounds

    NASA Astrophysics Data System (ADS)

    Cheng, Ya-Ping; Wen, Liang-Jian; Zhang, Peng; Cao, Xing-Zhong

    2017-01-01

    Reactor neutrino experiments build large-scale detector systems to detect neutrinos. In liquid scintillator, a neutral bound state of a positron and an electron, named positronium, can be formed. The spin triplet state is called ortho-positronium (o-Ps). In this article, an experiment is designed to measure the lifetime of o-Ps, giving a result of 3.1 ns. A PSD parameter based on photon emission time distribution (PETD) was constructed to discriminate e+/e-. Finally, the application of e+/e- discrimination in the JUNO experiment is shown. It helps suppress 8He/9Li backgrounds and improves the sensitivity by 0.6 in χ 2 analysis with an assumption of σ = 1 ns PMT Transit Time Spread, which will bring a smearing effect to the PETD. Supported by National Natural Science Foundation of China (11575226, 11475197, 11205183)

  17. A simple method to determine bioethanol content in gasoline using two-step extraction and liquid scintillation counting.

    PubMed

    Yunoki, Shunji; Saito, Masaaki

    2009-12-01

    A simple method for determining bioethanol content in gasoline containing bioethanol (denoted as E-gasoline in this study) is urgently required. Liquid scintillation counting (LSC) was employed based on the principle that (14)C exists in bioethanol but not in synthetic ethanol. Bioethanol was extracted in two steps by water from E-gasoline containing 3% (E3) or 10% (E10) bioethanol. The (14)C radioactivity was measured by LSC and converted to the amount of bioethanol. The bioethanol content in E-gasoline was determined precisely from the partition coefficient in the extraction and the amount of bioethanol in the water phases: 2.98+/-0.10% for E3 and 10.0+/-0.1% for E10 (means+/-SD; n=3). It appears that this method can be used to determine bioethanol content in E-gasoline quickly and easily.

  18. Solid scintillation counting: a new technique for measuring radiolabeled compounds.

    PubMed

    Wunderly, S W

    1989-01-01

    This report describes the theory and practice of anew solid scintillator technique for measurement of radiolabeled compounds useful in bioresearch. Solid scintillation counting is expected to replace liquid scintillation counting in certain applications involving non-volatile radiolabeled substrates.

  19. p-Terphenyl: An alternative to liquid scintillators for neutron detection

    NASA Astrophysics Data System (ADS)

    Sardet, A.; Varignon, C.; Laurent, B.; Granier, T.; Oberstedt, A.

    2015-08-01

    A detailed characterization of doped paraterphenyl (p-Terphenyl) neutron detectors was obtained by means of γ-sources and a 252Cf fission chamber. The intrinsic timing resolution, the energy resolution up to 2 MeVee, and the electron-equivalent energy calibration were determined using γ-sources. The neutron time-of-flight spectrum from the spontaneous fission of 252Cf provided information on the proton energy calibration, the light output function, and the intrinsic neutron detection efficiency between 0 and 8 MeV for a threshold of 250 keV. Measurements of the latter were also performed using monoenergetic neutron beams. The applied experimental methods were cross-checked using two BC501A scintillation detectors, which were previously calibrated at the Physikalisch-Technische Bundesanstalt in Braunschweig, Germany. Results were compared to Monte-Carlo simulations performed using NRESP7 and NEFF7 codes.

  20. Simultaneous determination of gross alpha, gross beta and ²²⁶Ra in natural water by liquid scintillation counting.

    PubMed

    Fons, J; Zapata-García, D; Tent, J; Llauradó, M

    2013-11-01

    The determination of gross alpha, gross beta and (226)Ra activity in natural waters is useful in a wide range of environmental studies. Furthermore, gross alpha and gross beta parameters are included in international legislation on the quality of drinking water [Council Directive 98/83/EC]. In this work, a low-background liquid scintillation counter (Wallac, Quantulus 1220) was used to simultaneously determine gross alpha, gross beta and (226)Ra activity in natural water samples. Sample preparation involved evaporation to remove (222)Rn and its short-lived decay daughters. The evaporation process concentrated the sample ten-fold. Afterwards, a sample aliquot of 8 mL was mixed with 12 mL of Ultima Gold AB scintillation cocktail in low-diffusion vials. In this study, a theoretical mathematical model based on secular equilibrium conditions between (226)Ra and its short-lived decay daughters is presented. The proposed model makes it possible to determine (226)Ra activity from two measurements. These measurements also allow determining gross alpha and gross beta simultaneously. To validate the proposed model, spiked samples with different activity levels for each parameter were analysed. Additionally, to evaluate the model's applicability in natural water, eight natural water samples from different parts of Spain were analysed. The eight natural water samples were also characterised by alpha spectrometry for the naturally occurring isotopes of uranium ((234)U, (235)U and (238)U), radium ((224)Ra and (226)Ra), (210)Po and (232)Th. The results for gross alpha and (226)Ra activity were compared with alpha spectrometry characterization, and an acceptable concordance was obtained.

  1. Enhancement of archaeological heritage. El Risco de las Cuevas at Perales de Tajuña, Madrid (Spain)

    NASA Astrophysics Data System (ADS)

    Freire-Lista, David Martin; Alvarez de Buergo, Mónica; Fort, Rafael

    2016-04-01

    Heritage conservation has a great impact on the economy of a country. The enhancement of archaeological sites is an investment that promotes tourism and culture. The interdisciplinary knowledge of heritage should be the basis of its management. Preventive actions, non-destructive analytical techniques and monitoring for the conservation of these assets should be promoted. "El Risco de las Cuevas" is a highly decayed and nearly vertical gypsum escarpment which contains a series of dwellings excavated during the Chalcolithic and much more recent times. It is located at Perales de Tajuña, 40 km southeast of Madrid, Spain. This monument is approximately 70 metres high and 500 metres wide. It was listed as a cultural and monumental heritage site by the regional government of Madrid in 1998. The gypsum escarpment housing the dwellings forms part of a lower Miocene unit (Madrid Basin). Debris cones with a mixture of debris from the lower, medium and upper units are found at the bottom of the rockwall. The vulnerability of this monument to atmospheric agents has been studied using "in situ" monitoring techniques of humidity, temperature and rate of rockfalls. Drones have been used for aerial photography in the highest areas of the escarpment and have provided an information network of fractures likely to cause rockfall. Gypsum artificial accelerated ageing has been carried out in the laboratory, including freeze/thaw, wet/dry, thermal shock and dissolution tests. To determine the response of these accelerated ageing processes, density, micro-roughness, ultrasound velocities (Vp and Vs), air permeability and microscopy measurements were made before, during and after ageing tests. Geomorphological studies, rates of decay, material characteristics and durability tests indicate that the decay is controlled by the mineralogy, clay content and porosity of the gypsum rock, as well as microclimate, temperature changes and rock fractures. Rockfalls are particularly relevant in the

  2. Monitoring gross alpha and beta activity in liquids by using ZnS(Ag) scintillation detectors

    SciTech Connect

    Stevanato, L.; Cester, D.; Filippi, D.; Lunardon, M.; Mistura, G.; Moretto, S.; Viesti, G.; Badocco, D.; Pastore, P.; Romanini, F.

    2015-07-01

    In this work the possibility of monitoring gross alpha and beta activity in liquids using EJ-444 was investigated. Specific tests were carried out to determine the change of the detector properties in water tests. Possible protecting coating is also proposed and tested. Alpha/beta real-time monitoring in liquids is a goal of the EU project TAWARA{sub R}TM. (authors)

  3. Study of NaI(Tl) scintillator cooled down to liquid nitrogen temperature

    NASA Astrophysics Data System (ADS)

    Sibczyński, P.; Moszyński, M.; Szczęśniak, T.; Czarnacki, W.

    2012-11-01

    Since early 50's NaI(Tl) scintillators have been commonly used in many branches of physics and industry due to their relatively low price, high light output and fair energy resolution. Through this period of time, both spectroscopic and luminescence properties of NaI(Tl) were measured at room temperature. In this work, the gamma spectrometry and the luminescence properties of the NaI(Tl) at LN2 temperature were studied. The gamma spectrometry was carried out with the light readout by avalanche photodiodes cooled down together with the crystal in the cryostat. It was observed that non-proportionality measured at LN2 temperature is significantly better than that at room temperature. The energy resolution of the NaI(Tl) at 662 keV measured at LN2 temperature was estimated to be 6.57%, comparable to that measured commonly at RT with photomultipliers. A decay time measurement of the NaI(Tl) at LN2 showed a slower decay of 736±10 ns.

  4. Verification of proton range, position, and intensity in IMPT with a 3D liquid scintillator detector system

    PubMed Central

    Archambault, L.; Poenisch, F.; Sahoo, N.; Robertson, D.; Lee, A.; Gillin, M. T.; Mohan, R.; Beddar, S.

    2012-01-01

    Purpose: Intensity-modulated proton therapy (IMPT) using spot scanned proton beams relies on the delivery of a large number of beamlets to shape the dose distribution in a highly conformal manner. The authors have developed a 3D system based on liquid scintillator to measure the spatial location, intensity, and depth of penetration (energy) of the proton beamlets in near real-time. Methods: The detector system consists of a 20 × 20 × 20 cc liquid scintillator (LS) material in a light tight enclosure connected to a CCD camera. This camera has a field of view of 25.7 by 19.3 cm and a pixel size of 0.4 mm. While the LS is irradiated, the camera continuously acquires images of the light distribution produced inside the LS. Irradiations were made with proton pencil beams produced with a spot-scanning nozzle. Pencil beams with nominal ranges in water between 9.5 and 17.6 cm were scanned to irradiate an area of 10 × 10 cm square on the surface of the LS phantom. Image frames were acquired at 50 ms per frame. Results: The signal to noise ratio of a typical Bragg peak was about 170. Proton range measured from the light distribution produced in the LS was accurate to within 0.3 mm on average. The largest deviation seen between the nominal and measured range was 0.6 mm. Lateral position of the measured pencil beam was accurate to within 0.4 mm on average. The largest deviation seen between the nominal and measured lateral position was 0.8 mm; however, the accuracy of this measurement could be improved by correcting light scattering artifacts. Intensity of single proton spots were measured with precision ranging from 3 % for the smallest spot intensity (0.005 MU) to 0.5 % for the largest spot (0.04 MU). Conclusions: Our LS detector system has been shown to be capable of fast, submillimeter spatial localization of proton spots delivered in a 3D volume. This system could be used for beam range, intensity and position verification in IMPT. PMID:22380355

  5. Verification of proton range, position, and intensity in IMPT with a 3D liquid scintillator detector system

    SciTech Connect

    Archambault, L.; Poenisch, F.; Sahoo, N.; Robertson, D.; Lee, A.; Gillin, M. T.; Mohan, R.; Beddar, S.

    2012-03-15

    Purpose: Intensity-modulated proton therapy (IMPT) using spot scanned proton beams relies on the delivery of a large number of beamlets to shape the dose distribution in a highly conformal manner. The authors have developed a 3D system based on liquid scintillator to measure the spatial location, intensity, and depth of penetration (energy) of the proton beamlets in near real-time. Methods: The detector system consists of a 20 x 20 x 20 cc liquid scintillator (LS) material in a light tight enclosure connected to a CCD camera. This camera has a field of view of 25.7 by 19.3 cm and a pixel size of 0.4 mm. While the LS is irradiated, the camera continuously acquires images of the light distribution produced inside the LS. Irradiations were made with proton pencil beams produced with a spot-scanning nozzle. Pencil beams with nominal ranges in water between 9.5 and 17.6 cm were scanned to irradiate an area of 10 x 10 cm square on the surface of the LS phantom. Image frames were acquired at 50 ms per frame. Results: The signal to noise ratio of a typical Bragg peak was about 170. Proton range measured from the light distribution produced in the LS was accurate to within 0.3 mm on average. The largest deviation seen between the nominal and measured range was 0.6 mm. Lateral position of the measured pencil beam was accurate to within 0.4 mm on average. The largest deviation seen between the nominal and measured lateral position was 0.8 mm; however, the accuracy of this measurement could be improved by correcting light scattering artifacts. Intensity of single proton spots were measured with precision ranging from 3 % for the smallest spot intensity (0.005 MU) to 0.5 % for the largest spot (0.04 MU). Conclusions: Our LS detector system has been shown to be capable of fast, submillimeter spatial localization of proton spots delivered in a 3D volume. This system could be used for beam range, intensity and position verification in IMPT.

  6. Absolute standardizations of (99m)Tc and (57)Co by 4π electron-gamma liquid scintillation coincidence counting for SIRTI and SIR comparisons.

    PubMed

    Rooy, M W van; Staden, M J van; Simpson, B R S; Lubbe, J

    2017-07-25

    The radionuclides (99m)Tc and (57)Co were standardized via absolute liquid scintillation counting techniques. We provide the first technical report on the absolute standardization of (99m)Tc using 4π(LS)e-γ coincidence counting. The low detection efficiency of low-energy conversion electrons translates into a large efficiency extrapolation range. A simulation indicated that the γ-ray interacting with the liquid scintillator introduces curvature to the count rate vs. efficiency relationship, the approximation of the functional form used for extrapolation providing the main measurement uncertainty for (99m)Tc. A detection efficiency analysis for both radionuclides is presented. Results from the standardizations, and SIRTI and SIR comparison exercises are reported. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Results of a 3-ton experiment with a Gd loaded liquid scintillator target performed in the frame of LVD at LNGS

    NASA Astrophysics Data System (ADS)

    Aglietta, M.; Bari, G.; Bruno, G.; Fulgione, W.; Kemp, E.; Porta, A.; Malguine, A.; Cattadori, C.; Danilov, N.; DiVacri, A.; Krilov, Yu.; Yanovich, E.; LVD Collaboration

    2011-12-01

    In the frame of the LVD experimental program in the INFN Gran Sasso National Laboratory (LNGS), we performed a 3-ton Gd experiment, by loading (up to 0.1% in weight) the LVD organic liquid scintillator with a Gd organic salt developed and produced as the result of a joint INFN/INR research activity. Performances, feasibility and preliminary results on stability have been presented.

  8. Development of a System for Survey of Radon Concentration of the Dayton Area Using a Liquid Scintillation Counter and Analysis of the Data

    DTIC Science & Technology

    1992-03-01

    conversion, a calibration factor, an elution time constant, and adsorption time constant were calculated . The procedure for handling the vials...the vials were done on Packard Tri- Carb 2200CA Liquid Scintillation Analyzer. To calculate radon concentration in pCi/l from net counts per minute...started to set up a system for a large scale survey of radon concentration. He used one of Sharp’s protocol for calculating the radon concentration. Using

  9. Validation of a procedure for the analysis of (226)Ra in naturally occurring radioactive materials using a liquid scintillation counter.

    PubMed

    Kim, Hyuncheol; Jung, Yoonhee; Ji, Young-Yong; Lim, Jong-Myung; Chung, Kun Ho; Kang, Mun Ja

    2017-01-01

    An analytical procedure for detecting (226)Ra in naturally occurring radioactive materials (NORMs) using a liquid scintillation counter (LSC) was developed and validated with reference materials (zircon matrix, bauxite matrix, coal fly ash, and phosphogypsum) that represent typical NORMs. The (226)Ra was released from samples by a fusion method and was separated using sulfate-coprecipitation. Next, a (222)Rn-emanation technique was applied for the determination of (226)Ra. The counting efficiency was 238 ± 8% with glass vials. The recovery for the reference materials was 80 ± 11%. The linearity of the method was tested with different masses of zircon matrix reference materials. Using 15 types of real NORMs, including raw materials and by-products, this LSC method was compared with γ-spectrometry, which had already been validated for (226)Ra analysis. The correlation coefficient for the results from the LSC method and γ-spectrometry was 0.993 ± 0.058.

  10. Radiation hazards and lifetime risk assessment of tap water using liquid scintillation counting and high-resolution gamma spectrometry.

    PubMed

    Al-Shboul, K F; Alali, A E; Batayneh, I M; Al-Khodire, H Y

    2017-09-12

    In this work, two complementary techniques, viz. liquid scintillation counting and high-resolution gamma spectrometry are utilized to analyze radionuclides concentrations in tap water of Irbid governorate, Jordan, and study their correlation. Gross alpha and gross beta concentrations, in the tap water samples collected from the nine districts of Irbid governorate, ranged from <82 to 484 mBq/L with a mean of 295 mBq/L and from <216 to 984 mBq/L with a mean of 611 mBq/L, respectively. Furthermore, gamma spectrometry analysis, for the tap water samples, shows that the activity concentrations of (226)Ra, (232)Th, and (40)K ranged between <19 and 302 mBq/L, 24 to 119 mBq/L, and <101 to 342 mBq/L, respectively. There was a weak or even no correlation among the identified natural radionuclides with no trace of artificial radioactivity. In addition, the results of both techniques show that storing tap water in drilled wells leads to higher levels of radioactivity concentrations beyond the international permissible limits. Furthermore, the average lifetime risk and annual effective dose received by age-grouped inhabitants due to direct and indirect tap water consumption are evaluated, where most of the received dose is attributed to (226)Ra. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Determination of radiostrontium in milk samples by ultra-low-level liquid scintillation counting: a validated approach.

    PubMed

    dell'Oro, Daniela; Iammarino, Marco; Bortone, Nicola; Mangiacotti, Michele; Chiaravalle, Antonio Eugenio

    2014-01-01

    Strontium-90 is a hazardous radionuclide derived from nuclear fission processes, and it decays emitting high-energy beta-particles forming yttrium-90. It may be easily absorbed in humans through several food supply chains, since it is chemically similar to some important biological elements such as potassium and calcium. In this work an analytical method for the determination of radiostrontium in milk by liquid scintillation counting was developed in order to obtain a precise quantification at low activity concentration levels. Moreover, a full validative approach was applied to confirm method reliability. Good analytical performance was obtained by developing an in-house validation model according to Regulation 882/2004/EC and Decision 657/2002/EC with a good selectivity, a decision threshold and detection limit corresponding to 0.003 and 0.006 Bq l⁻¹ (α = β = 0.05) respectively, a repeatability value, expressed as CV%, equal to 13%, a mean recovery value equal to 102.5% and a measurement uncertainty equal to 11.5%. Strontium and yttrium chemical yields were determined by a reliable analytical method by inductively coupled mass spectrometry, assuring a suitable correction of final result. The results of the method validation, combined with a quality control assurance, performed on a reference material, demonstrated that the procedure represents a substantial improvement in the determination of ⁹⁰Sr relating to accurate confirmation analyses.

  12. Determination of (222)Rn absorption properties of polycarbonate foils by liquid scintillation counting. Application to (222)Rn measurements.

    PubMed

    Mitev, K; Cassette, P; Georgiev, S; Dimitrova, I; Sabot, B; Boshkova, T; Tartès, I; Pressyanov, D

    2016-03-01

    This work demonstrates that a Liquid Scintillation Counting (LSC) technique using a Triple to Double Coincidence Ratio counter with extending dead-time is very appropriate for the accurate measurement of (222)Rn activity absorbed in thin polycarbonate foils. It is demonstrated that using a toluene-based LS cocktail, which dissolves polycarbonates, the (222)Rn activity absorbed in thin Makrofol N foil can be determined with a relative standard uncertainty of about 0.7%. A LSC-based application of the methodology for determination of the diffusion length of (222)Rn in thin polycarbonate foils is proposed and the diffusion length of (222)Rn in Makrofol N (38.9±1.3µm) and the partition coefficient of (222)Rn in Makrofol N from air (112±12, at 20°C) and from water (272±17, at 21°C) are determined. Calibration of commercial LS spectrometers for (222)Rn measurements by LSC of thin polycarbonate foils is performed and the minimum detectable activities by this technique are estimated.

  13. Digital processing of signals arising from organic liquid scintillators for applications in the mixed-field assessment of nuclear threats

    NASA Astrophysics Data System (ADS)

    Aspinall, M. D.; Joyce, M. J.; Mackin, R. O.; Jarrah, Z.; Peyton, A. J.

    2008-10-01

    The nuclear aspect of the CBRN* threat is often divided amongst radiological substances posing no criticality risk, often referred to as 'dirty bomb' scenarios, and fissile threats. The latter have the theoretical potential for criticality excursion, resulting in elevated neutron fluxes in addition to the γ-ray component that is common to dirty bombs. Even in isolation of the highly-unlikely criticality scenario, fissile substances often exhibit radiation fields comprising a significant neutron component which can require considerably different counterterrorism measures and clean-up methodologies. The contrast between these threats can indicate important differences in the relative sophistication of the perpetrators and their organizations. Consequently, the detection and discrimination of nuclear perils in terms of mixed-field content is an important assay in combating terrorist threats. In this paper we report on the design and implementation of a fast digitizer and embedded-processor for onthe- fly signal processing of events from organic liquid scintillators. A digital technique, known as Pulse Gradient Analysis (PGA), has been developed at Lancaster University for the digital discrimination of neutrons and γ rays. PGA has been deployed on bespoke hardware and demonstrates remarkable improvement over analogue methods for the assay of mixed fields and the real-time discrimination of neutrons and γ rays. In this regard the technology constitutes an attractive and affordable means for the discrimination of the radiation fields arising from fissile threats and those from dirty bombs. Data are presented demonstrating this capability with sealed radioactive sources.

  14. Separation and Purification and Beta Liquid Scintillation Analysis of Sm-151 in Savannah River Site and Hanford Site DOE High Level Waste

    SciTech Connect

    Dewberry, R.A.

    2001-02-13

    This paper describes development work to obtain a product phase of Sm-151 pure of any other radioactive species so that it can be determined in US Department of Energy high level liquid waste and low level solid waste by liquid scintillation {beta}-spectroscopy. The technique provides separation from {mu}Ci/ml levels of Cs-137, Pu alpha and Pu-241 {beta}-decay activity, and Sr-90/Y-90 activity. The separation technique is also demonstrated to be useful for the determination of Pm-147.

  15. Magnetic iron oxide nanoparticles for the collection and direct measurement of adsorbed alpha-emitting radionuclides from environmental waters by liquid scintillation analysis

    SciTech Connect

    O'Hara, Matthew J.; Addleman, R. Shane

    2017-01-01

    Radioactive contamination in the environment, be it from accidental or intentional release, can create an urgent need to assess water and food supplies, the environment, and monitor human health. Alpha-emitting radionuclides represent the most ionizing, and therefore the most damaging, form of radiation when internalized. Additionally, because of its ease of energy attenuation in solids or liquids, alpha emissions cannot be reliably monitored using non-destructive means. In the event of such an emergency, rapid and efficient methods will be needed to screen scores of samples (food, water, and human excreta) within a short time window. Unfortunately, the assay of alpha-emitting radionuclides using traditional radioanalytical methods is typically labor intensive and time consuming. The creation of analytical counting sources typically requires a series of chemical treatment steps to achieve well performing counting sources. In an effort to devise radioanalytical methods that are fast, require little labor, and minimize the use of toxic or corrosive agents, researchers at PNNL have evaluated magnetite (Fe3O4) nanoparticles as extracting agents for alpha-emitting radionuclides from chemically unmodified aqueous systems. It is demonstrated that bare magnetic nanoparticles exhibit high affinity for representative α-emitting radionuclides (241Am and 210Po) from representative aqueous matrices: river and ground water. Furthermore, use of the magnetic properties of these materials to concentrate the sorbed analyte from the bulk aqueous solution has been demonstrated. The nanoparticle concentrate can be either directly dispensed into scintillation cocktail, or first dissolved and then added to scintillation cocktail as a solution for alpha emission assay by liquid scintillation analysis. Despite the extreme quench caused by the metal oxide suspensions, the authors have demonstrated that quench correction features available on modern liquid scintillation analyzers can be

  16. Measurement of 90sr in aqueous samples using liquid scintillation counting with full spectrum DPM method.

    PubMed

    Lee, M H; Chung, K H; Choi, G K; Lee, C W

    2002-08-01

    90Sr activity was measured with the full spectrum DPM (FS-DPM) counting method after plotting the quench correction curves of 90Sr and 90Y, and the FS-DPM method was applied to determine the 90Sr in liquid waste samples. The optimum regions of 90Sr and 90Y were set for measuring 90Sr with the dual label DPM (DL-DPM) method. The direct measurement of purified 90Sr with spectrum unfolding techniques could overcome the disadvantages of the DL-DPM method. The activities of 90Sr in the 90Sr/90Y standardized solution measured with the FS-DPM protocols were close to the true activity. The concentrations of 90Sr in the liquid waste samples measured with the FS-DPM counting method were compared with those obtained with conventional methods.

  17. MO-F-CAMPUS-T-03: Verification of Range, SOBP Width, and Output for Passive-Scattering Proton Beams Using a Liquid Scintillator Detector

    SciTech Connect

    Henry, T; Robertson, D; Therriault-Proulx, F; Beddar, S

    2015-06-15

    Purpose: Liquid scintillators have been shown to provide fast and high-resolution measurements of radiation beams. However, their linear energy transfer-dependent response (quenching) limits their use in proton beams. The purpose of this study was to develop a simple and fast method to verify the range, spread-out Bragg peak (SOBP) width, and output of a passive-scattering proton beam with a liquid scintillator detector, without the need for quenching correction. Methods: The light signal from a 20×20×20 cm3 liquid scintillator tank was collected with a CCD camera. Reproducible landmarks on the SOBP depth-light curve were identified which possessed a linear relationship with the beam range and SOBP width. The depth-light profiles for three beam energies (140, 160 and 180 MeV) with six SOBP widths at each energy were measured with the detector. Beam range and SOBP width calibration factors were obtained by comparing the depth-light curve landmarks with the nominal range and SOBP width for each beam setting. The daily output stability of the liquid scintillator detector was also studied by making eight repeated output measurements in a cobalt-60 beam over the course of two weeks. Results: The mean difference between the measured and nominal beam ranges was 0.6 mm (σ=0.2 mm), with a maximum difference of 0.9 mm. The mean difference between the measured and nominal SOBP widths was 0.1 mm (σ=1.8 mm), with a maximum difference of 4.0 mm. Finally an output variation of 0.14% was observed for 8 measurements performed over 2 weeks. Conclusion: A method has been developed to determine the range and SOBP width of a passive-scattering proton beam in a liquid scintillator without the need for quenching correction. In addition to providing rapid and accurate beam range and SOBP measurements, the detector is capable of measuring the output consistency with a high degree of precision. This project was supported in part by award number CA182450 from the National Cancer

  18. A measurement of the time profile of scintillation induced by low energy gamma-rays in liquid xenon with the XMASS-I detector

    NASA Astrophysics Data System (ADS)

    Takiya, H.; Abe, K.; Hiraide, K.; Ichimura, K.; Kishimoto, Y.; Kobayashi, K.; Kobayashi, M.; Moriyama, S.; Nakahata, M.; Norita, T.; Ogawa, H.; Sekiya, H.; Takachio, O.; Takeda, A.; Tasaka, S.; Yamashita, M.; Yang, B. S.; Kim, N. Y.; Kim, Y. D.; Itow, Y.; Kegasa, R.; Kobayashi, K.; Masuda, K.; Fushimi, K.; Martens, K.; Suzuki, Y.; Fujita, R.; Hosokawa, K.; Miuchi, K.; Oka, N.; Onishi, Y.; Takeuchi, Y.; Kim, Y. H.; Lee, J. S.; Lee, K. B.; Lee, M. K.; Fukuda, Y.; Nishijima, K.; Nakamura, S.

    2016-10-01

    We report the measurement of the emission time profile of scintillation from gamma-ray induced events in the XMASS-I 832 kg liquid xenon scintillation detector. Decay time constant was derived from a comparison of scintillation photon timing distributions between the observed data and simulated samples in order to take into account optical processes such as absorption and scattering in liquid xenon. Calibration data of radioactive sources, 55Fe, 241Am, and 57Co were used to obtain the decay time constant. Assuming two decay components, τ1 and τ2, the decay time constant τ2 increased from 27.9 ns to 37.0 ns as the gamma-ray energy increased from 5.9 keV to 122 keV. The accuracy of the measurement was better than 1.5 ns at all energy levels. A fast decay component with τ1 ∼ 2 ns was necessary to reproduce data. Energy dependencies of τ2 and the fraction of the fast decay component were studied as a function of the kinetic energy of electrons induced by gamma-rays. The obtained data almost reproduced previously reported results and extended them to the lower energy region relevant to direct dark matter searches.

  19. Investigating the Anisotropic Scintillation Response in Organic Crystal Scintillator Detectors

    NASA Astrophysics Data System (ADS)

    Schuster, Patricia Frances

    This dissertation presents several studies that experimentally characterize the scintillation anisotropy in organic crystal scintillators. These include measurements of neutron, gamma-ray and cosmic muon interactions in anthracene, a historical benchmark among organic scintillator materials, to confirm and extend measurements previously available in the literature. The gamma-ray and muon measurements provide new experimental confirmation that no scintillation anisotropy is present in their interactions. Observations from these measurements have updated the hypothesis for the physical mechanism that is responsible for the scintillation anisotropy concluding that a relatively high dE/dx is required in order to produce a scintillation anisotropy. The directional dependence of the scintillation output in liquid and plastic materials was measured to experimentally confirm that no scintillation anisotropy correlated to detector orientation exists in amorphous materials. These observations confirm that the scintillation anisotropy is not due to an external effect on the measurement system, and that a fixed, repeating structure is required for a scintillation anisotropy. The directional dependence of the scintillation output in response to neutron interactions was measured in four stilbene crystals of various sizes and growth-methods. The scintillation anisotropy in these materials was approximately uniform, indicating that the crystal size, geometry, and growth method do not significantly impact the effect. Measurements of three additional pure crystals and two mixed crystals were made. These measurements showed that 1) the magnitude of the effect varies with energy and material, 2) the relationship between the light output and pulse shape anisotropy varies across materials, and 3) the effect in mixed materials is very complex. These measurements have informed the hypothesis of the mechanism that produces the directional dependence. By comparing the various relationships

  20. Scintillator material

    DOEpatents

    Anderson, David F.; Kross, Brian J.

    1992-01-01

    An improved scintillator material comprising cerium fluoride is disclosed. Cerium fluoride has been found to provide a balance of good stopping power, high light yield and short decay constant that is superior to known scintillator materials such as thallium-doped sodium iodide, barium fluoride and bismuth germanate. As a result, cerium fluoride is favorably suited for use as a scintillator material in positron emission tomography.

  1. Scintillator material

    DOEpatents

    Anderson, David F.; Kross, Brian J.

    1994-01-01

    An improved scintillator material comprising cerium fluoride is disclosed. Cerium fluoride has been found to provide a balance of good stopping power, high light yield and short decay constant that is superior to known scintillator materials such as thallium-doped sodium iodide, barium fluoride and bismuth germanate. As a result, cerium fluoride is favorably suited for use as a scintillator material in positron emission tomography.

  2. Scintillator material

    DOEpatents

    Anderson, D.F.; Kross, B.J.

    1992-07-28

    An improved scintillator material comprising cerium fluoride is disclosed. Cerium fluoride has been found to provide a balance of good stopping power, high light yield and short decay constant that is superior to known scintillator materials such as thallium-doped sodium iodide, barium fluoride and bismuth germanate. As a result, cerium fluoride is favorably suited for use as a scintillator material in positron emission tomography. 4 figs.

  3. Scintillator material

    DOEpatents

    Anderson, D.F.; Kross, B.J.

    1994-06-07

    An improved scintillator material comprising cerium fluoride is disclosed. Cerium fluoride has been found to provide a balance of good stopping power, high light yield and short decay constant that is superior to known scintillator materials such as thallium-doped sodium iodide, barium fluoride and bismuth germanate. As a result, cerium fluoride is favorably suited for use as a scintillator material in positron emission tomography. 4 figs.

  4. Quenching equation for scintillation

    NASA Astrophysics Data System (ADS)

    Kato, Takahisa

    1980-06-01

    A mathematical expression is postulated showing the relationship between counting rate and quenching agent concentration in a liquid scintillation solution. The expression is more suited to a wider range of quenching agent concentrations than the Stern-Volmer equation. An estimation of the quenched correction is demonstrated using the expression.

  5. Sensitivity and uncertainty analysis of the simulation of 123I and 54Mn gamma and X-ray emissions in a liquid scintillation vial.

    PubMed

    Bignell, L J; Mo, L; Alexiev, D; Hashemi-Nezhad, S R

    2010-01-01

    Radiation transport simulations of the most probable gamma- and X-ray emissions of (123)I and (54)Mn in a three photomultiplier tube liquid scintillation detector have been carried out. A Geant4 simulation was used to acquire energy deposition spectra and interaction probabilities with the scintillant, as required for absolute activity measurement using the triple to double coincidence ratio (TDCR) method. A sensitivity and uncertainty analysis of the simulation model is presented here. The uncertainty in the Monte Carlo simulation results due to the input parameter uncertainties was found to be more significant than the statistical uncertainty component for a typical number of simulated decay events. The model was most sensitive to changes in the volume of the scintillant. Estimates of the relative uncertainty associated with the simulation outputs due to the combined stochastic and input uncertainties are provided. A Monte Carlo uncertainty analysis of an (123)I TDCR measurement indicated that accounting for the simulation uncertainties increases the uncertainty of efficiency of the logical sum of double coincidence by 5.1%. Copyright 2009 Elsevier Ltd. All rights reserved.

  6. CNO and pep neutrino spectroscopy in Borexino: Measurement of the deep-underground production of cosmogenic C11 in an organic liquid scintillator

    NASA Astrophysics Data System (ADS)

    Back, H.; Balata, M.; Bellini, G.; Benziger, J.; Bonetti, S.; Caccianiga, B.; Calaprice, F.; D'Angelo, D.; de Bellefon, A.; de Kerret, H.; Derbin, A.; Etenko, A.; Ford, R.; Franco, D.; Galbiati, C.; Gazzana, S.; Giammarchi, M.; Goretti, A.; Grieb, C.; Harding, E.; Heusser, G.; Ianni, A.; Ianni, A. M.; Kobychev, V. V.; Korga, G.; Kozlov, Y.; Kryn, D.; Laubenstein, M.; Lendvai, C.; Leung, M.; Litvinovich, E.; Lombardi, P.; Machulin, I.; Maneira, J.; Manuzio, D.; Manuzio, G.; Masetti, F.; Mazzucato, U.; McCarty, K.; Meroni, E.; Miramonti, L.; Monzani, M. E.; Muratova, V.; Niedermeier, L.; Oberauer, L.; Obolensky, M.; Ortica, F.; Pallavicini, M.; Papp, L.; Perasso, L.; Pocar, A.; Raghavan, R. S.; Ranucci, G.; Razeto, A.; Sabelnikov, A.; Salvo, C.; Schoenert, S.; Shutt, T.; Simgen, H.; Skorokhvatov, M.; Smirnov, O.; Sotnikov, A.; Sukhotin, S.; Suvorov, Y.; Tarasenkov, V.; Tartaglia, R.; Vignaud, D.; Vogelaar, R. B.; von Feilitzsch, F.; Vyrodov, V.; Wójcik, M.; Zaimidoroga, O.; Zuzel, G.

    2006-10-01

    Borexino is an experiment for low-energy neutrino spectroscopy at the Gran Sasso underground laboratories. It is designed to measure the monoenergetic Be7 solar neutrino flux in real time, via neutrino-electron elastic scattering in an ultrapure organic liquid scintillator. Borexino has the potential to also detect neutrinos from the pep fusion process and the CNO cycle. For this measurement to be possible, radioactive contamination in the detector must be kept extremely low. Once sufficiently clean conditions are met, the main background source is C11, produced in reactions induced by the residual cosmic muon flux on C12. In the process, a free neutron is almost always produced. C11 can be tagged on an event-by-event basis by looking at the threefold coincidence with the parent muon track and the subsequent neutron capture on protons. This coincidence method has been implemented on the Borexino Counting Test Facility data. We report on the first event-by-event identification of in situ muon-induced C11 in a large underground scintillator detector. We measure a C11 production rate of 0.130 ± 0.026(stat) ± 0.014(syst) day-1 ton-1, in agreement with predictions from both experimental studies performed with a muon beam on a scintillator target and ab initio estimations based on the C11 producing nuclear reactions.

  7. Determination of 222Rn in fresh water: development of a robust method of analysis by alpha/beta separation liquid scintillation spectrometry.

    PubMed

    Pates, Jacqueline M; Mullinger, Neil J

    2007-01-01

    Liquid scintillation spectrometry is used widely for determining (222)Rn in natural waters; however, the benefits of alpha/beta separation have not been fully explored. The extractants toluene and Ultima Gold F were compared, and both performed well for a range of extreme waters. A robust method for calibrating extraction and counting efficiencies has been developed. Detection limits are 20 mBql(-1) (toluene) and 16 mBql(-1) (UGF) for a 60 min count and 600-ml sample, halving the required sample volume.

  8. Deuterated-xylene (xylene-d10; EJ301D): A new, improved deuterated liquid scintillator for neutron energy measurements without time-of-flight

    SciTech Connect

    Becchetti, F. D.; Raymond, R. S.; Torres-Isea, R. O.; Di Fulvio, A.; Clarke, S. D.; Pozzi, S. A.; Febbraro, M.

    2016-03-02

    In conjunction with Eljen Technology, Inc. (Sweetwater,TX) we have designed, constructed, and evaluated a 3 in. x 3 in. deuterated-xylene organic liquid scintillator (C8D10; EJ301D) as a fast neutron detector. Similar to deuterated benzene (C6D6; NE230, BC537, and E1315) this scintillator can provide good pulse shape discrimination between neutrons and gamma rays, has good timing characteristics, and can provide a light spectrum with peaks corresponding to discrete neutron energy groups up to ca. 20 MeV. Unlike benzene -based detectors, deuterated xylene is less volatile, less toxic, is not known to be carcinogenic, has a higher flashpoint, and hence is much safer for many applications. In addition E1301D can provide slightly more light output and better PSD than deuterated-benzene scintillators. We show that, as with deuterated-benzene scintillators, the light -response spectra can be unfolded to provide useable neutron energy spectra without need for time-of-flight (ToF). An array of these detectors arranged at many angles close to a reaction target can be much more effective ( x 10 to x 100 or more) than an array of long-path ToF detectors which must utilize a narrowly-bunched and pulse-selected beam. Here, as we demonstrate using a small Van de Graaff accelerator, measurements can thus be performed when a bunched and pulse -selected beam (as needed for time-of-flight) is not available.

  9. Deuterated-xylene (xylene-d10; EJ301D): A new, improved deuterated liquid scintillator for neutron energy measurements without time-of-flight

    DOE PAGES

    Becchetti, F. D.; Raymond, R. S.; Torres-Isea, R. O.; ...

    2016-03-02

    In conjunction with Eljen Technology, Inc. (Sweetwater,TX) we have designed, constructed, and evaluated a 3 in. x 3 in. deuterated-xylene organic liquid scintillator (C8D10; EJ301D) as a fast neutron detector. Similar to deuterated benzene (C6D6; NE230, BC537, and E1315) this scintillator can provide good pulse shape discrimination between neutrons and gamma rays, has good timing characteristics, and can provide a light spectrum with peaks corresponding to discrete neutron energy groups up to ca. 20 MeV. Unlike benzene -based detectors, deuterated xylene is less volatile, less toxic, is not known to be carcinogenic, has a higher flashpoint, and hence is muchmore » safer for many applications. In addition E1301D can provide slightly more light output and better PSD than deuterated-benzene scintillators. We show that, as with deuterated-benzene scintillators, the light -response spectra can be unfolded to provide useable neutron energy spectra without need for time-of-flight (ToF). An array of these detectors arranged at many angles close to a reaction target can be much more effective ( x 10 to x 100 or more) than an array of long-path ToF detectors which must utilize a narrowly-bunched and pulse-selected beam. Here, as we demonstrate using a small Van de Graaff accelerator, measurements can thus be performed when a bunched and pulse -selected beam (as needed for time-of-flight) is not available.« less

  10. Deuterated-xylene (xylene-d10; EJ301D): A new, improved deuterated liquid scintillator for neutron energy measurements without time-of-flight

    NASA Astrophysics Data System (ADS)

    Becchetti, F. D.; Raymond, R. S.; Torres-Isea, R. O.; Di Fulvio, A.; Clarke, S. D.; Pozzi, S. A.; Febbraro, M.

    2016-06-01

    In conjunction with Eljen Technology, Inc. (Sweetwater,TX) we have designed, constructed, and evaluated a 3 in. ×3 in. deuterated-xylene organic liquid scintillator (C8D10; EJ301D) as a fast neutron detector. Similar to deuterated benzene (C6D6; NE230, BC537, and EJ315) this scintillator can provide good pulse-shape discrimination between neutrons and gamma rays, has good timing characteristics, and can provide a light spectrum with peaks corresponding to discrete neutron energy groups up to ca. 20 MeV. Unlike benzene-based detectors, deuterated xylene is less volatile, less toxic, is not known to be carcinogenic, has a higher flashpoint, and hence is much safer for many applications. In addition EJ301D can provide slightly more light output and better PSD than deuterated-benzene scintillators. We show that, as with deuterated-benzene scintillators, the light-response spectra can be unfolded to provide useable neutron energy spectra without need for time-of-flight (ToF). An array of these detectors arranged at many angles close to a reaction target can be much more effective (×10 to ×100 or more) than an array of long-path ToF detectors which must utilize a narrowly-bunched and pulse-selected beam. As we demonstrate using a small Van de Graaff accelerator, measurements can thus be performed when a bunched and pulse-selected beam (as needed for time-of-flight) is not available.

  11. Scintillation Counters

    NASA Astrophysics Data System (ADS)

    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.

  12. Motion-induced alterations in 2-deoxyglucose uptake in brainstem nuclei of squirrel monkeys: autoradiographic and liquid scintillation studies.

    PubMed

    Brizzee, K R; Dunlap, W P

    1983-01-01

    Each of 8 young adult female squirrel monkeys were injected via a femoral vein cannula with 167 microCi/100 g body weight of 2-(1,2-3H)-deoxy-D-glucose (2-DG) (New England Nuclear, 37.3 Ci/mmol) in 0.5 ml sterile saline. 4 additional female squirrel monkeys were injected in the same manner with 100 microCi/100 g body weight of the (3H)-2-DG. 2 h after this initial injection the original 8 animals were injected with 16.7 microCi/100 g body weight of 2-(1-14C)-deoxy-D-glucose (51.3 mCi/mmol) in 0.5 ml sterile saline. The 4 additional animals were injected with 25 microCi/100 g body weight of the (14C)-2-DG. Half of the animals each dose level were restrained in the upright position with Velcro straps and a nontraumatic moulded plastic head holder on a modified animal restraint board [Withrow and Devine, 1972] with the head in the sagittal plane but tilted forward about 20 degrees. They were then subjected to horizontal rotary motion at 25 rpm together with a vertical movement of 6 inches at 0.5 Hz for 1 h in a lighted room. The other half of the animals at each dose were restrained in the same manner and maintained in a quiescent state. At the end of this period each animal was anesthetized with ketamine, and the brain was quickly dissected out and frozen in isopentane cooled to -60 degrees C with dry ice. Transverse cryostat sections (-15 degrees C) of the brainstem were cut alternately at 200 and 20 microns from the nucleus gracilis caudally through the superior vestibular nucleus rostrally. Micropunch samples of the individual vestibular nuclei, and other brainstem nuclei and areas were obtained from the 200-microns sections with a modification of the method of Eik-Nes and Brizzee with a small stainless steel punch measuring 850 microns in diameter. The frozen punch samples were prepared for liquid scintillation counting (Beckman LS7500 system). Differential (3H) and (14C) counts (cpm) were made employing external standards. The 20-microns sections were prepared

  13. Determination of the 10Be half-life by multicollector ICP-MS and liquid scintillation counting

    NASA Astrophysics Data System (ADS)

    Chmeleff, Jérôme; von Blanckenburg, Friedhelm; Kossert, Karsten; Jakob, Dieter

    2010-01-01

    A new method was designed and used for determining the half-life of the isotope 10Be. The method is based on (1) accurate 10Be/ 9Be measurements of 9Be-spiked solutions of a 10Be-rich master solution using multicollector ICP mass spectrometry (MC-ICP-MS) and (2) liquid scintillation counting (LSC) using the CIEMAT/NIST method for determining the activity concentrations of the solutions whose 10Be concentrations were determined by mass spectrometry. Important requirements for the success of this approach (a) was the previous coating of glass ampoules filled for counting experiments with 9Be, thereby reducing the risk of the adsorptive loss of 10Be; (b) the removal of Boron from solutions to be measured by MC-ICP-MS by cation chromatography without the introduction of mass fractionation and (c) the accurate determination of the mass bias of 10Be/ 9Be measurements by ICP-MS which are always affected by the space-charge effect. The mass bias factor was determined to be 1.1862 ± 0.071 for 10Be/ 9Be from careful fitting and error propagation of ratios of measured Li, B, Si, Cr, Fe, Cu, Sr, Nd, Hf, Tl and U standard solutions of known composition under the same measurement conditions. Employing this factor, an absolute 10Be/ 9Be ratio of 1.464 ± 0.014 was determined for a first dilution of the 10Be-rich master solution. This solution is now available as an absolute Be ratio standard in AMS measurements. Finally, a half-life of (1.386 ± 0.016) My (standard uncertainty) was calculated. This value is much more precise than previous estimates and was derived from a fully independent set of experiments. In a parallel, fully independent study using the same master solution, Korschinek et al. [35] have determined a half-life of (1.388 ± 0.018) My. The combined half-life and uncertainty amounts to (1.387 ± 0.012) My. We suggest the use of this value in nuclear studies and in studies that make use of cosmogenic 10Be in environmental and geologic samples.

  14. A Dose Distribution Study of Uranyl Nitrate in Zebrafish using Liquid Scintillation and Passivated Implanted Planar Silicon Detectors

    NASA Astrophysics Data System (ADS)

    Alshammari, Ohud Fhaid

    Standard curves for a Perkin Elmer TriCarb 2800 liquid scintillation detector (LSC) and a Ludlum 3030p Passivated Implanted Planar Silicon detector have been developed and utilized for studying the dose distribution of depleted uranium (DU) within zebrafish. The DU source was crystallized uranyl nitrate (N2O8U•6H2O) solution, normally used for staining in electron microscopy with a manufactured average specific activity of 0.3 uCi/g. Zebrafish, both larvae and adults, were exposed to three different mass concentrations, dissected, dissolved and counted using an LSC. The counts were compared to the standard curve correlating the measured activity to that of the mass absorbed. It was found that the larvae were more tolerant to the toxicity of the DU by almost a factor of 10 showing survival up to 200 ppm where the adults had zero survival when exposed to concentrations above 20 ppm. The absorbed DU was observed to concentrate more heavily in the skeletal structure and the blood containing organs (liver and heart) when comparing the relative mass concentrations observed in each organ compared to that of the whole fish exposed to the same concentration. The highest absorbed dose rate was found in the skeletal system at 3.5 mGy/d followed by the blood containing organs at 2.2 mGy/d when exposed to 20 ppm DU. It was also noted that the bioconcentration factors (BCF) of the adult zebrafish followed the same trend observed in similar studies. As the mass concentration of DU was lowered, the BCF calculated for fish exposed increased with a BCF of 130.6 found for those exposed to 20 ppm U and a BCF of 774.2 for fish exposed to 2 ppm. This method shows to present a suitable way of developing a dose distribution for DU along with similar isotopes which will be instrumental in studying the long term effects of more specific exposures to natural radioactive metals combined with other common environmental exposures.

  15. Multiparameter liquid scintillation spectrometry

    NASA Astrophysics Data System (ADS)

    Polach, Henry; Kojola, Hannu; Nurmi, Jarmo; Soini, Erkki

    1984-11-01

    Multiparameter analog to digital conversion and multichannel pulse height analyses, enabling simultaneous acquisition of four different 1024 ch energy spectra, enhance the accuracy of low-level counting of 3H and 14C. The new LS spectrometer, the QUANTULUS, is based on the concept of "total optimisation" where all known factors enabling reduction of background and data validation have been considered. These involve: special counting vials, random access — variable time base — sequential counting, electronic background reduction, and a " master spectra" library with continuous monitoring of user selected validity parameters by high resolution MCA.

  16. A comparison of digital zero-crossing and charge-comparison methods for neutron/γ-ray discrimination with liquid scintillation detectors

    NASA Astrophysics Data System (ADS)

    Nakhostin, M.

    2015-10-01

    In this paper, we have compared the performances of the digital zero-crossing and charge-comparison methods for n/γ discrimination with liquid scintillation detectors at low light outputs. The measurements were performed with a 2″×2″ cylindrical liquid scintillation detector of type BC501A whose outputs were sampled by means of a fast waveform digitizer with 10-bit resolution, 4 GS/s sampling rate and one volt input range. Different light output ranges were measured by operating the photomultiplier tube at different voltages and a new recursive algorithm was developed to implement the digital zero-crossing method. The results of our study demonstrate the superior performance of the digital zero-crossing method at low light outputs when a large dynamic range is measured. However, when the input range of the digitizer is used to measure a narrow range of light outputs, the charge-comparison method slightly outperforms the zero-crossing method. The results are discussed in regard to the effects of the quantization noise and the noise filtration performance of the zero-crossing filter.

  17. Scintillator Measurements for SNO+

    NASA Astrophysics Data System (ADS)

    Kaptanoglu, Tanner; SNO+ Collaboration

    2016-03-01

    SNO+ is a neutrino detector located 2km underground in the SNOLAB facility with the primary goal of searching for neutrinoless double beta decay. The detector will be filled with a liquid scintillator target primarily composed of linear alkyl benzene (LAB). As charged particles travel through the detector the LAB produces scintillation light which is detected by almost ten thousand PMTs. The LAB is loaded with Te130, an isotope known to undergo double beta decay. Additionally, the LAB is mixed with an additional fluor and wavelength shifter to improve the light output and shift the light to a wavelength regime in which the PMTs are maximally efficient. The precise scintillator optics drastically affect the ultimate sensitivity of SNO+. I will present work being done to measure the optical properties of the SNO+ scintillator cocktail. The measured properties are used as input to a scintillation model that allows us to extrapolate to the SNO+ scale and ultimately predict the sensitivity of the experiment. Additionally, I will present measurements done to characterize the R5912 PMT, a candidate PMT for the second phase of SNO+ that provides better light collection, improved charge resolution, and a narrower spread in timing.

  18. [Development of a simple quantitative method for the strontium-89 concentration of radioactive liquid waste using the plastic scintillation survey meter for beta rays].

    PubMed

    Narita, Hiroto; Tsuchiya, Yuusuke; Hirase, Kiyoshi; Uchiyama, Mayuki; Fukushi, Masahiro

    2012-11-01

    Strontium-89 (89Sr: pure beta, E; 1.495 MeV-100%, halflife: 50.5 days) chloride is used as pain relief from bone metastases. An assay of 89Sr is difficult because of a pure beta emitter. For management of 89Sr, we tried to evaluate a simple quantitative method for the 59Sr concentration of radioactive liquid waste using scintillation survey meter for beta rays. The counting efficiency of the survey meter with this method was 35.95%. A simple 30 minutes measurement of 2 ml of the sample made the quantitative measurement of 89Sr practical. Reducing self-absorption of the beta ray in the solution by counting on the polyethlene paper improved the counting efficiency. Our method made it easy to manage the radioactive liquid waste under the legal restrictions.

  19. LArGe: Background suppression using liquid argon (LAr) scintillation for 0 νββ decay search with enriched germanium (Ge) detectors

    NASA Astrophysics Data System (ADS)

    Di Marco, M.; Peiffer, P.; Schönert, S.

    2007-10-01

    Measurements with a bare p-type high purity germanium diode (HPGe) submerged in a 19 kg liquid argon (LAr) scintillation detector at MPIK-Heidelberg are reported. The liquid argon-germanium system (LArGe) is operated as a 4 π anti-Compton spectrometer to suppress backgrounds in the HPGe. This R&D is carried out in the framework of the Gerda experiment which searches for 0 νββ decays with HPGe detectors enriched in 76Ge. The goal of this work is to develop a novel method to discriminate backgrounds in 0 νββ search which would ultimately allow to investigate the effective neutrino mass free of background events down to the inverse mass hierarchy scale. Other applications in low-background counting are expected.

  20. Pulse Shape Analysis Techniques in Liquid Scintillator for the Identification and Suppression of Radioactive Backgrounds to Neutrinoless Double Beta Decay

    NASA Astrophysics Data System (ADS)

    Dunger, J.; SNO+ Collaboration

    2017-09-01

    Spatial/temporal patterns of light produced in large scintillator experiments like SNO+ are sensitive to particle ID/count. Here we set out rules for choosing a test statistic for hypothesis testing based on timing and demonstrate two applications to the SNO+ [1] neutrinoless double beta decay (0νββ) experiment: constraining internal 60Co contamination, and suppressing the 2.6 MeV γ background created by 208Tl decay on the acrylic vessel.

  1. Absolute measurements of the response function of an NE213 organic liquid scintillator for the neutron energy range up to 206 /MeV

    NASA Astrophysics Data System (ADS)

    Nakao, Noriaki; Kurosawa, Tadahiro; Nakamura, Takashi; Uwamino, Yoshitomo

    2001-05-01

    The absolute values of the neutron response functions of a 12.7 cm diameter by 12.7 cm long NE213 organic liquid scintillator were measured using a quasi-monoenergetic neutron field in the energy range of 66- 206 MeV via the 7Li(p,n) 7Be reaction in the ring cyclotron facility at RIKEN. The measured response functions were compared with calculations using a Monte Carlo code developed by Cecil et al. The measurements clarified that protons escaping through the scintillator wall induced by high-energy neutrons increase from 6% for 66 MeV neutrons to 35% for 206 MeV neutrons, and that this wall effect causes a difficult problem for n-γ discrimination. Measured response functions without the wall-effect events were also obtained by eliminating the escaping-proton events in the analysis, and compared with calculations using a modified Monte Carlo code. Comparisons between the measurements and calculations both with and without any wall-effect events gave a good agreement, but some discrepancy in the light output distribution could be found, mainly because the deuteron generation process was not taken into account in the calculation. The calculated efficiencies for 10 MeVee threshold, however, also gave good agreement within about 10% with the measurements.

  2. Measurements of high energy neutrons penetrated through iron shields using the Self-TOF detector and an NE213 organic liquid scintillator

    NASA Astrophysics Data System (ADS)

    Sasaki, M.; Nakao, N.; Nunomiya, T.; Nakamura, T.; Fukumura, A.; Takada, M.

    2002-11-01

    Neutron energy spectra penetrated through iron shields were measured using the Self-TOF detector and an NE213 organic liquid scintillator which have been newly developed by our group at the Heavy-Ion Medical Accelerator in Chiba (HIMAC) of National Institute of Radiological Sciences (NIRS), Japan. Neutrons were generated by bombarding 400 MeV/nucleon C ion on a thick (stopping-length) copper target. The neutron spectra in the energy range from 20 to 800 MeV were obtained through the FORIST unfolding code with their response functions and compared with the MCNPX calculations combined with the LA150 cross section library. The neutron fluence measured by the NE213 detector was simulated by the track length estimator in the MCNPX, and evaluated the contribution of the room-scattered neutrons. The calculations are in fairly good agreement with the measurements. Neutron fluence attenuation lengths were obtained from the experimental results and the calculation.

  3. Determination of sulfur in fly ash and fuel oil standard reference materials by radiochemical neutron activation analysis and liquid scintillation counting

    SciTech Connect

    Li, M.; Filby, R.H.

    1983-12-01

    Sulfur was determined in NBS Coal Fly Ash (SRM 1633) and Residual Fuel Oils (SRM's 1619, 1620a, 1634a) by radiochemical neutron activation analysis (NAA) using the /sup 34/S(n,..gamma..)/sup 35/S reaction. The /sup 35/S was separated from solutions of the standards by either cation-anion exchange on Dowex 50W-X8/Dowex 1-X8 or by adsorption on Al/sub 2/O/sub 3/. Liquid scintillation counting of aqueous solutions was used for /sup 35/S measurement. The /sup 35/Cl(n,p)/sup 35/S interference was corrected for by measurement of chlorine by instrumental NAA. The method may be applied to very small samples of fly ash or air particulates (<10/sup -3/ g). 1 figure, 5 tables.

  4. Analysis of low level radioactive metabolites in biological fluids using high-performance liquid chromatography with microplate scintillation counting: method validation and application.

    PubMed

    Zhu, Mingshe; Zhao, Weiping; Vazquez, Natasha; Mitroka, James G

    2005-09-01

    TopCount, a microplate scintillation counter (MSC), has been recently employed as an off-line liquid radiochromatographic detector for radioactive metabolite profile analysis. The present study was undertaken to validate TopCount for metabolite profiling with respect to sensitivity, accuracy, precision and radioactivity recovery. Matrix effects of various human samples on TopCount performance and capability of MSC for volatile metabolite analysis were also investigated. TopCount had a limit of detection (LOD) of 5 DPM and a limit of quantification (LOQ) of 15 DPM for [(14)C]-labeled compounds at a 10min counting time. It was two-fold more sensitive than a liquid scintillation counter (LSC), and 50-100-fold more sensitive than a radioactivity flow detector (RFD). TopCount had comparable accuracy and precision to RFD, and comparable precision to LSC for determining relative abundance of metabolites. Human liver microsome incubation (up to 1 mL), plasma (up to 1 mL), urine (up to 2 mL) and feces (up to 50mg) had no significant quenching effects on TopCount performance. Benzoic acid, a volatile metabolite, was detected by TopCount, but not by Microbeta counter after microplates were dried under vacuum. Radioactivity recovery in HPLC-MSC analysis was reliably determined using an LSC-based method. Examples of using HPLC-MSC for analysis of low levels of radioactive metabolites are presented, including determination of plasma metabolite profile, in vitro reactive metabolites trapped by [(3)H]glutathione, and metabolite concentrations in an enzyme kinetic experiment. The data from this study strongly suggest that HPLC in combination with TopCount is a viable alternative analytical tool for detection and quantification of low levels of radioactive metabolites in biological fluids.

  5. Organic liquid scintillation detectors for on-the-fly neutron/gamma alarming and radionuclide identification in a pedestrian radiation portal monitor

    NASA Astrophysics Data System (ADS)

    Paff, Marc Gerrit; Ruch, Marc L.; Poitrasson-Riviere, Alexis; Sagadevan, Athena; Clarke, Shaun D.; Pozzi, Sara

    2015-07-01

    We present new experimental results from a radiation portal monitor based on the use of organic liquid scintillators. The system was tested as part of a 3He-free radiation portal monitor testing campaign at the European Commission's Joint Research Centre in Ispra, Italy, in February 2014. The radiation portal monitor was subjected to a wide range of test conditions described in ANSI N42.35, including a variety of gamma-ray sources and a 20,000 n/s 252Cf source. A false alarm test tested whether radiation portal monitors ever alarmed in the presence of only natural background. The University of Michigan Detection for Nuclear Nonproliferation Group's system triggered zero false alarms in 2739 trials. It consistently alarmed on a variety of gamma-ray sources travelling at 1.2 m/s at a 70 cm source to detector distance. The neutron source was detected at speeds up to 3 m/s and in configurations with up to 8 cm of high density polyethylene shielding. The success of on-the-fly radionuclide identification varied with the gamma-ray source measured as well as with which of two radionuclide identification methods was used. Both methods used a least squares comparison between the measured pulse height distributions to library spectra to pick the best match. The methods varied in how the pulse height distributions were modified prior to the least squares comparison. Correct identification rates were as high as 100% for highly enriched uranium, but as low as 50% for 241Am. Both radionuclide identification algorithms produced mixed results, but the concept of using liquid scintillation detectors for gamma-ray and neutron alarming in radiation portal monitor was validated.

  6. Measurement of the scintillation time spectra and pulse-shape discrimination of low-energy β and nuclear recoils in liquid argon with DEAP-1

    SciTech Connect

    Amaudruz, P. -A.; Batygov, M.; Beltran, B.; Bonatt, J.; Boudjemline, K.; Boulay, M. G.; Broerman, B.; Bueno, J. F.; Butcher, A.; Cai, B.; Caldwell, T.; Chen, M.; Chouinard, R.; Cleveland, B. T.; Cranshaw, D.; Dering, K.; Duncan, F.; Fatemighomi, N.; Ford, R.; Gagnon, R.; Giampa, P.; Giuliani, F.; Gold, M.; Golovko, V. V.; Gorel, P.; Grace, E.; Graham, K.; Grant, D. R.; Hakobyan, R.; Hallin, A. L.; Hamstra, M.; Harvey, P.; Hearns, C.; Hofgartner, J.; Jillings, C. J.; Kuźniak, M.; Lawson, I.; La Zia, F.; Li, O.; Lidgard, J. J.; Liimatainen, P.; Lippincott, W. H.; Mathew, R.; McDonald, A. B.; McElroy, T.; McFarlane, K.; McKinsey, D. N.; Mehdiyev, R.; Monroe, J.; Muir, A.; Nantais, C.; Nicolics, K.; Nikkel, J.; Noble, A. J.; O’Dwyer, E.; Olsen, K.; Ouellet, C.; Pasuthip, P.; Peeters, S. J. M.; Pollmann, T.; Rau, W.; Retière, F.; Ronquest, M.; Seeburn, N.; Skensved, P.; Smith, B.; Sonley, T.; Tang, J.; Vázquez-Jáuregui, E.; Veloce, L.; Walding, J.; Ward, M.

    2016-09-17

    The DEAP-1 low-background liquid argon detector has been used to measure scintillation pulse shapes of beta decays and nuclear recoil events and to demonstrate the feasibility of pulse-shape discrimination down to an electron-equivalent energy of 20 keVee. The relative intensities of singlet/triplet states in liquid argon have been measured as a function of energy between 15 and 500 keVee for both beta and nuclear recoils. Using a triple-coincidence tag we find the fraction of beta events that are misidentified as nuclear recoils to be less than 6 x 10-8 between 43-86 keVee and that the discrimination parameter agrees with a simple analytic model. The discrimination measurement is currently limited by nuclear recoils induced by cosmic-ray generated neutrons, and is expected to improve by operating the detector underground at SNOLAB. The analytic model predicts a beta misidentification fraction of 10-10 for an electron-equivalent energy threshold of 20 keVee. This reduction allows for a sensitive search for spin-independent scattering of WIMPs from 1000 kg of liquid argon with a WIMP-nucleon cross-section sensitivity of 10-46 cm2.

  7. Measurement of the scintillation time spectra and pulse-shape discrimination of low-energy β and nuclear recoils in liquid argon with DEAP-1

    DOE PAGES

    Amaudruz, P. -A.; Batygov, M.; Beltran, B.; ...

    2016-09-17

    The DEAP-1 low-background liquid argon detector has been used to measure scintillation pulse shapes of beta decays and nuclear recoil events and to demonstrate the feasibility of pulse-shape discrimination down to an electron-equivalent energy of 20 keVee. The relative intensities of singlet/triplet states in liquid argon have been measured as a function of energy between 15 and 500 keVee for both beta and nuclear recoils. Using a triple-coincidence tag we find the fraction of beta events that are misidentified as nuclear recoils to be less than 6 x 10-8 between 43-86 keVee and that the discrimination parameter agrees with amore » simple analytic model. The discrimination measurement is currently limited by nuclear recoils induced by cosmic-ray generated neutrons, and is expected to improve by operating the detector underground at SNOLAB. The analytic model predicts a beta misidentification fraction of 10-10 for an electron-equivalent energy threshold of 20 keVee. This reduction allows for a sensitive search for spin-independent scattering of WIMPs from 1000 kg of liquid argon with a WIMP-nucleon cross-section sensitivity of 10-46 cm2.« less

  8. Waveshifters and Scintillators for Ionizing Radiation Detection

    SciTech Connect

    B.Baumgaugh; J.Bishop; D.Karmgard; J.Marchant; M.McKenna; R.Ruchti; M.Vigneault; L.Hernandez; C.Hurlbut

    2007-12-11

    Scintillation and waveshifter materials have been developed for the detection of ionizing radiation in an STTR program between Ludlum Measurements, Inc. and the University of Notre Dame. Several new waveshifter materials have been developed which are comparable in efficiency and faster in fluorescence decay than the standard material Y11 (K27) used in particle physics for several decades. Additionally, new scintillation materials useful for fiber tracking have been developed which have been compared to 3HF. Lastly, work was done on developing liquid scintillators and paint-on scintillators and waveshifters for high radiation environments.

  9. New Scintillators for Photosensitive Gaseous Detectors

    NASA Astrophysics Data System (ADS)

    Charpak, G.; Peskov, V.; Scigocki, D.; Valbis, J.

    A new family of scintillators are presented. Their properties are similar to those of barium fluoride, and the spectrum of the scintillation emission is between 140 and 300 nm. Our latest efficiency measurements of ethyl ferrocene and triethylamine liquid or caesium iodide solid photocathodes, in parallel-plate avalanche chambers (PPACs) at high electric field, are also presented. We discuss the revolutionary consequences of the combination of the new scintillators with PPACs with semitransparent photocathodes deposited on the crystals, such as high speed, high resistance to radiation damage, compacity, high gamma efficiency, and applications to tracking devices with scintillation optical fibres.

  10. Scintillation and ionization responses of liquid xenon to low energy electronic and nuclear recoils at drift fields from 236 V /cm to 3.93 kV /cm

    NASA Astrophysics Data System (ADS)

    Lin, Qing; Fei, Jialing; Gao, Fei; Hu, Jie; Wei, Yuehuan; Xiao, Xiang; Wang, Hongwei; Ni, Kaixuan

    2015-08-01

    We present new measurements of the scintillation and ionization yields in liquid xenon for low energy electronic (about 3 - 7 keVe e ) and nuclear recoils (about 8 - 20 keVn r ) at different drift fields from 236 V /cm to 3.93 kV /cm , using a three-dimensional sensitive liquid xenon time projection chamber with high energy and position resolutions. Our measurement of signal responses to nuclear recoils agrees with predictions from the NEST model. However, our measured ionization (scintillation) yields for electronic recoils are consistently higher (lower) than those from the NEST model by about 5 e-/keVe e (ph /keVe e) at all scanned drift fields. New recombination parameters based on the Thomas-Imel box model are derived from our data. Given the lack of precise measurement of scintillation and ionization yields for low energy electronic recoils in liquid xenon previously, our new measurement provides so far the best available data covering low energy regions at different drift fields for liquid xenon detectors relevant to dark matter searches.

  11. SCINTILLATION SPECTROMETER

    DOEpatents

    Bell, P.R.; Francis, J.E.

    1960-06-21

    A portable scintillation spectrometer is described which is especially useful in radio-biological studies for determining the uptake and distribution of gamma -emitting substances in tissue. The spectrometer includes a collimator having a plurality of apertures that are hexagonal in cross section. Two crystals are provided: one is activated to respond to incident rays from the collimator; the other is not activated and shields the first from external radiation.

  12. Plastic scintillation dosimetry: Optimal selection of scintillating fibers and scintillators

    SciTech Connect

    Archambault, Louis; Arsenault, Jean; Gingras, Luc; Sam Beddar, A.; Roy, Rene; Beaulieu, Luc

    2005-07-15

    Scintillation dosimetry is a promising avenue for evaluating dose patterns delivered by intensity-modulated radiation therapy plans or for the small fields involved in stereotactic radiosurgery. However, the increase in signal has been the goal for many authors. In this paper, a comparison is made between plastic scintillating fibers and plastic scintillator. The collection of scintillation light was measured experimentally for four commercial models of scintillating fibers (BCF-12, BCF-60, SCSF-78, SCSF-3HF) and two models of plastic scintillators (BC-400, BC-408). The emission spectra of all six scintillators were obtained by using an optical spectrum analyzer and they were compared with theoretical behavior. For scintillation in the blue region, the signal intensity of a singly clad scintillating fiber (BCF-12) was 120% of that of the plastic scintillator (BC-400). For the multiclad fiber (SCSF-78), the signal reached 144% of that of the plastic scintillator. The intensity of the green scintillating fibers was lower than that of the plastic scintillator: 47% for the singly clad fiber (BCF-60) and 77% for the multiclad fiber (SCSF-3HF). The collected light was studied as a function of the scintillator length and radius for a cylindrical probe. We found that symmetric detectors with nearly the same spatial resolution in each direction (2 mm in diameter by 3 mm in length) could be made with a signal equivalent to those of the more commonly used asymmetric scintillators. With augmentation of the signal-to-noise ratio in consideration, this paper presents a series of comparisons that should provide insight into selection of a scintillator type and volume for development of a medical dosimeter.

  13. Plastic scintillation dosimetry: Optimal selection of scintillating fibers and scintillators.

    PubMed

    Archambault, Louis; Arsenault, Jean; Gingras, Luc; Sam Beddar, A; Roy, René; Beaulieu, Luc

    2005-07-01

    Scintillation dosimetry is a promising avenue for evaluating dose patterns delivered by intensity-modulated radiation therapy plans or for the small fields involved in stereotactic radiosurgery. However, the increase in signal has been the goal for many authors. In this paper, a comparison is made between plastic scintillating fibers and plastic scintillator. The collection of scintillation light was measured experimentally for four commercial models of scintillating fibers (BCF-12, BCF-60, SCSF-78, SCSF-3HF) and two models of plastic scintillators (BC-400, BC-408). The emission spectra of all six scintillators were obtained by using an optical spectrum analyzer and they were compared with theoretical behavior. For scintillation in the blue region, the signal intensity of a singly clad scintillating fiber (BCF-12) was 120% of that of the plastic scintillator (BC-400). For the multiclad fiber (SCSF-78), the signal reached 144% of that of the plastic scintillator. The intensity of the green scintillating fibers was lower than that of the plastic scintillator: 47% for the singly clad fiber (BCF-60) and 77% for the multiclad fiber (SCSF-3HF). The collected light was studied as a function of the scintillator length and radius for a cylindrical probe. We found that symmetric detectors with nearly the same spatial resolution in each direction (2 mm in diameter by 3 mm in length) could be made with a signal equivalent to those of the more commonly used asymmetric scintillators. With augmentation of the signal-to-noise ratio in consideration, this paper presents a series of comparisons that should provide insight into selection of a scintillator type and volume for development of a medical dosimeter. © 2005 American Association of Physicists in Medicine.

  14. Plastic scintillation dosimetry: optimal selection of scintillating fibers and scintillators.

    PubMed

    Archambault, Louis; Arsenault, Jean; Gingras, Luc; Beddar, A Sam; Roy, René; Beaulieu, Luc

    2005-07-01

    Scintillation dosimetry is a promising avenue for evaluating dose patterns delivered by intensity-modulated radiation therapy plans or for the small fields involved in stereotactic radiosurgery. However, the increase in signal has been the goal for many authors. In this paper, a comparison is made between plastic scintillating fibers and plastic scintillator. The collection of scintillation light was measured experimentally for four commercial models of scintillating fibers (BCF-12, BCF-60, SCSF-78, SCSF-3HF) and two models of plastic scintillators (BC-400, BC-408). The emission spectra of all six scintillators were obtained by using an optical spectrum analyzer and they were compared with theoretical behavior. For scintillation in the blue region, the signal intensity of a singly clad scintillating fiber (BCF-12) was 120% of that of the plastic scintillator (BC-400). For the multiclad fiber (SCSF-78), the signal reached 144% of that of the plastic scintillator. The intensity of the green scintillating fibers was lower than that of the plastic scintillator: 47% for the singly clad fiber (BCF-60) and 77% for the multiclad fiber (SCSF-3HF). The collected light was studied as a function of the scintillator length and radius for a cylindrical probe. We found that symmetric detectors with nearly the same spatial resolution in each direction (2 mm in diameter by 3 mm in length) could be made with a signal equivalent to those of the more commonly used asymmetric scintillators. With augmentation of the signal-to-noise ratio in consideration, this paper presents a series of comparisons that should provide insight into selection of a scintillator type and volume for development of a medical dosimeter.

  15. Linear lateral vibration of axisymmetric liquid briges

    NASA Astrophysics Data System (ADS)

    Ferrera, C.; Montanero, J. M.; Cabezas, M. G.

    A liquid bridge is a mass of liquid sustained by the action of the surface tension force between two parallel supporting disks Apart from their basic scientific interest a liquid bridge can be considered as the simplest idealization of the configuration appearing in the floating zone technique used for crystal growth and purification of high melting point materials footnote Messeguer et al emph Crystal Growth Res bf 5 27 1999 This has conferred considerable interest on the study of liquid bridges not only in fluid mechanics but also in the field of material engineering The axisymmetric dynamics of an isothermal liquid bridge has been frequently analysed over the past years The studies have considered different phenomena such as free oscillations footnote Montanero emph E J Mech B Fluids bf 22 169 2003 footnote Acero and Montanero emph Phys Fluids bf 17 078105 2005 forced vibrations footnote Perales and Messeguer emph Phys Fluids A bf 4 1110 1992 g-jitter effects footnote Messeguer and Perales emph Phys Fluids A bf 3 2332 1991 extensional deformation footnote Zhang et al emph J Fluid Mech bf 329 207 1996 and breakup process footnote Espino et al emph Phys Fluids bf 14 3710 2002 among others Works considering the nonaxisymmetric dynamical behaviour of a liquid bridge has been far less common footnote Sanz and Diez emph J Fluid Mech bf 205 503 1989 In the present study the linear vibration of an axisymmetric liquid

  16. Development of liquid scintillation based 4πβ(LS)-γ coincidence counting system and demonstration of its performance by standardization of ⁶⁰Co.

    PubMed

    Kulkarni, D B; Anuradha, R; Joseph, Leena; Tomar, B S

    2013-02-01

    A single-vial, single-PMT 4πβ(LS)-γ coincidence counting system has been developed at the Radiation Safety Systems Division, BARC. It has advantages of simple sample preparation, higher counting efficiency and the absence of self absorption over the conventional proportional counter based 4πβ(PC)-γ coincidence counting system. The performance of the system is demonstrated by standardizing a (60)Co solution using the 4πβ(LS)-γ coincidence counting system, 4πβ(PC)-γ coincidence counting system and CIEMAT/NIST method and comparing the results obtained by each method. The detection efficiency of liquid scintillation counter of the 4πβ(LS)-γ coincidence counting system was varied by color quenching, by chemical quenching and by varying the bias voltage applied to the LSC PMT. For the proportional counter based 4πβ(PC)-γ coincidence counting system the detection efficiency was varied by source self absorption. The activity concentrations obtained using the 4πβ(LS)-γ coincidence counting system, the 4πβ(PC)-γ coincidence counting system and the CIEMAT/NIST method are comparable within the uncertainty limits. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Beta Emitter Radionuclides (90Sr) Contamination in Animal Feed: Validation and Application of a Radiochemical Method by Ultra Low Level Liquid Scintillation Counting

    PubMed Central

    Iammarino, Marco; dell’Oro, Daniela; Bortone, Nicola

    2015-01-01

    90Sr is considered as a dangerous contaminant of agri-food supply chains due to its chemical affinity with Calcium, which makes its absorption in bones easy. 90Sr accumulation in raw materials and then in final products is particularly significant in relationship to its ability to transfer into animal source products. The radionuclides transfer (137Cs and 90Sr) from environment to forages and then to products of animal origin (milk, cow and pork meats) was studied and evaluated in different studies, which were carried out in contaminated areas, from Chernobyl disaster until today. In the present work, the development and validation of a radiochemical method for the detection of 90Sr in different types of animal feed, and the application of this technique for routinely control activities, are presented. Liquid scintillation counting was the employed analytical technique, since it is able to determine very low activity concentrations of 90Sr (<0.01 Bq Kg–1). All samples analysed showed a 90Sr contamination much higher than method detection limit (0.008 Bq kg–1). In particular, the highest mean activity concentration was registered in hay samples (2.93 Bq kg–1), followed by silage samples (2.07 Bq kg–1) and animal feeds (0.77 Bq kg–1). In fact, all samples were characterized by 90Sr activity concentrations much lower than reference limits. This notwithstanding, the necessity to monitor these levels was confirmed, especially considering that 90Sr is a possible carcinogen for human. PMID:27800378

  18. Beta Emitter Radionuclides ((90)Sr) Contamination in Animal Feed: Validation and Application of a Radiochemical Method by Ultra Low Level Liquid Scintillation Counting.

    PubMed

    Iammarino, Marco; dell'Oro, Daniela; Bortone, Nicola; Chiaravalle, Antonio Eugenio

    2015-02-03

    (90)Sr is considered as a dangerous contaminant of agri-food supply chains due to its chemical affinity with Calcium, which makes its absorption in bones easy. (90)Sr accumulation in raw materials and then in final products is particularly significant in relationship to its ability to transfer into animal source products. The radionuclides transfer ((137)Cs and (90)Sr) from environment to forages and then to products of animal origin (milk, cow and pork meats) was studied and evaluated in different studies, which were carried out in contaminated areas, from Chernobyl disaster until today. In the present work, the development and validation of a radiochemical method for the detection of (90)Sr in different types of animal feed, and the application of this technique for routinely control activities, are presented. Liquid scintillation counting was the employed analytical technique, since it is able to determine very low activity concentrations of (90)Sr (<0.01 Bq Kg(-1)). All samples analysed showed a (90)Sr contamination much higher than method detection limit (0.008 Bq kg(-1)). In particular, the highest mean activity concentration was registered in hay samples (2.93 Bq kg(-1)), followed by silage samples (2.07 Bq kg(-1)) and animal feeds (0.77 Bq kg(-1)). In fact, all samples were characterized by (90)Sr activity concentrations much lower than reference limits. This notwithstanding, the necessity to monitor these levels was confirmed, especially considering that (90)Sr is a possible carcinogen for human.

  19. Effective determination of the long-lived nuclide 41Ca in nuclear reactor bioshield concretes: comparison of liquid scintillation counting and accelerator mass spectrometry.

    PubMed

    Warwick, P E; Croudace, I W; Hillegonds, D J

    2009-03-01

    The routine application of liquid scintillation counting to (41)Ca determination has been hindered by the absence of traceable calibration standards of known (41)Ca activity concentrations. The introduction of the new IRMM (41)Ca mass-spectrometric standards with sufficiently high (41)Ca activities for radiometric detection has partly overcome this although accurate measurement of stable Ca concentrations coupled with precise half-life data are still required to correct the certified (41)Ca:(40)Ca ratios to (41)Ca activity concentrations. In this study, (41)Ca efficiency versus quench curves have been produced using the IRMM standard, and their accuracy validated by comparison with theoretical calculations of (41)Ca efficiencies. Further verification of the technique was achieved through the analysis of (41)Ca in a reactor bioshield core that had been previously investigated for other radionuclide variations. Calcium-41 activity concentrations of up to 25 Bq/g were detected. Accelerator mass spectrometry (AMS) measurements of the same suite of samples showed a very good agreement, providing validation of the procedure. Calcium-41 activity concentrations declined exponentially with distance from the core of the nuclear reactor and correlated well with the predicted neutron flux.

  20. Systematic study of particle quenching in organic scintillators

    NASA Astrophysics Data System (ADS)

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

    2013-01-01

    Among the different factors that affect measurements by organic scintillators, the majority of attention has been focused on those related to the scintillator (i.e., ionization, chemical, color and optical quenching), and less attention has been paid to the loss of energy before the particle (i.e., alpha or beta) arrives at the scintillator (i.e., particle quenching). This study evaluates the effect of particle quenching in different scintillation methods (i.e., using two plastic scintillation microspheres (PSm1 and PSm2), liquid scintillator and gel scintillator) by measuring solutions that contain increasing concentrations of NaCl, BaCl2 and glycerin. The results show the importance of particle quenching in PSm measurements because detection efficiency decreases with increasing concentrations of the quenching component, although the spectrum position and external standard parameter remain constant. The results have shown evidence of particle quenching, although at a lower magnitude, in the liquid scintillation or gel scintillation measurements. Moreover, the use of two PSm with different diameters and salty compound that alters the equilibrium of the liquid and gel emulsions also exemplified the importance of the transmission of optical photons through different scintillation media (i.e., optical quenching). Improvement and deterioration of the optical conditions on the scintillation media is manifested as a movement of the spectrum to higher and lower energies, respectively. The results obtained with PSm were confirmed by Monte Carlo simulation.

  1. The Use of Isotope Dilution Alpha Spectrometry and Liquid Scintillation Counting to Determine Radionuclides in Environmental Samples

    SciTech Connect

    Bylyku, Elida

    2009-04-19

    In Albania in recent years it has been of increasing interest to determine various pollutants in the environment and their possible effects on human health. The radiochemical procedure used to identify Pu, Am, U, Th, and Sr radioisotopes in soil, sediment, water, coal, and milk samples is described. The analysis is carried out in the presence of respective tracer solutions and combines the procedure for Pu analysis based on anion exchange, the selective method for Sr isolation based on extraction chromatography using Sr-Spec resin, and the application of the TRU-Spec column for separation of Am fraction. An acid digestion method has been applied for the decomposition of samples. The radiochemical procedure involves the separation of Pu from Th, Am, and Sr by anion exchange, followed by the preconcentration of Am and Sr by coprecipitation with calcium oxalate. Am is separated from Sr by extraction chromatography. Uranium is separated from the bulk elements by liquid-liquid extraction using UTEVA registered resin. Thin sources for alpha spectrometric measurements are prepared by microprecipitation with NdF3. Two International Atomic Energy Agency reference materials were analyzed in parallel with the samples.

  2. Metal-loaded organic scintillators for neutrino physics

    SciTech Connect

    Buck, Christian; Yeh, Minfang

    2016-08-03

    Organic liquid scintillators are used in many neutrino physics experiments of the past and present. In particular for low energy neutrinos when realtime and energy information are required, liquid scintillators have several advantages compared to other technologies. In many cases the organic liquid needs to be loaded with metal to enhance the neutrino signal over background events. Several metal loaded scintillators of the past suffered from chemical and optical instabilities, limiting the performance of these neutrino detectors. Different ways of metal loading are described in the article with a focus on recent techniques providing metal loaded scintillators that can be used under stable conditions for many years even in ton scale experiments. Lastly, we review applications of metal loaded scintillators in neutrino experiments and compare the performance as well as the prospects of different scintillator types.

  3. Metal-loaded organic scintillators for neutrino physics

    DOE PAGES

    Buck, Christian; Yeh, Minfang

    2016-08-03

    Organic liquid scintillators are used in many neutrino physics experiments of the past and present. In particular for low energy neutrinos when realtime and energy information are required, liquid scintillators have several advantages compared to other technologies. In many cases the organic liquid needs to be loaded with metal to enhance the neutrino signal over background events. Several metal loaded scintillators of the past suffered from chemical and optical instabilities, limiting the performance of these neutrino detectors. Different ways of metal loading are described in the article with a focus on recent techniques providing metal loaded scintillators that can bemore » used under stable conditions for many years even in ton scale experiments. Lastly, we review applications of metal loaded scintillators in neutrino experiments and compare the performance as well as the prospects of different scintillator types.« less

  4. Metal-loaded organic scintillators for neutrino physics

    SciTech Connect

    Buck, Christian; Yeh, Minfang

    2016-08-03

    Organic liquid scintillators are used in many neutrino physics experiments of the past and present. In particular for low energy neutrinos when realtime and energy information are required, liquid scintillators have several advantages compared to other technologies. In many cases the organic liquid needs to be loaded with metal to enhance the neutrino signal over background events. Several metal loaded scintillators of the past suffered from chemical and optical instabilities, limiting the performance of these neutrino detectors. Different ways of metal loading are described in the article with a focus on recent techniques providing metal loaded scintillators that can be used under stable conditions for many years even in ton scale experiments. Lastly, we review applications of metal loaded scintillators in neutrino experiments and compare the performance as well as the prospects of different scintillator types.

  5. Metal-loaded organic scintillators for neutrino physics

    NASA Astrophysics Data System (ADS)

    Buck, Christian; Yeh, Minfang

    2016-09-01

    Organic liquid scintillators are used in many neutrino physics experiments of the past and present. In particular for low energy neutrinos when realtime and energy information are required, liquid scintillators have several advantages compared to other technologies. In many cases the organic liquid needs to be loaded with metal to enhance the neutrino signal over background events. Several metal loaded scintillators of the past suffered from chemical and optical instabilities, limiting the performance of these neutrino detectors. Different ways of metal loading are described in the article with a focus on recent techniques providing metal loaded scintillators that can be used under stable conditions for many years even in ton scale experiments. Applications of metal loaded scintillators in neutrino experiments are reviewed and the performance as well as the prospects of different scintillator types are compared.

  6. Broad energy range neutron spectroscopy using a liquid scintillator and a proportional counter: Application to a neutron spectrum similar to that from an improvised nuclear device

    NASA Astrophysics Data System (ADS)

    Xu, Yanping; Randers-Pehrson, Gerhard; Marino, Stephen A.; Garty, Guy; Harken, Andrew; Brenner, David J.

    2015-09-01

    A novel neutron irradiation facility at the Radiological Research Accelerator Facility (RARAF) has been developed to mimic the neutron radiation from an Improvised Nuclear Device (IND) at relevant distances (e.g. 1.5 km) from the epicenter. The neutron spectrum of this IND-like neutron irradiator was designed according to estimations of the Hiroshima neutron spectrum at 1.5 km. It is significantly different from a standard reactor fission spectrum, because the spectrum changes as the neutrons are transported through air, and it is dominated by neutron energies from 100 keV up to 9 MeV. To verify such wide energy range neutron spectrum, detailed here is the development of a combined spectroscopy system. Both a liquid scintillator detector and a gas proportional counter were used for the recoil spectra measurements, with the individual response functions estimated from a series of Monte Carlo simulations. These normalized individual response functions were formed into a single response matrix for the unfolding process. Several accelerator-based quasi-monoenergetic neutron source spectra were measured and unfolded to test this spectroscopy system. These reference neutrons were produced from two reactions: T(p,n)3He and D(d,n)3He, generating neutron energies in the range between 0.2 and 8 MeV. The unfolded quasi-monoenergetic neutron spectra indicated that the detection system can provide good neutron spectroscopy results in this energy range. A broad-energy neutron spectrum from the 9Be(d,n) reaction using a 5 MeV deuteron beam, measured at 60 degrees to the incident beam was measured and unfolded with the evaluated response matrix. The unfolded broad neutron spectrum is comparable with published time-of-flight results. Finally, the pair of detectors were used to measure the neutron spectrum generated at the RARAF IND-like neutron facility and a comparison is made to the neutron spectrum of Hiroshima.

  7. Broad Energy Range Neutron Spectroscopy using a Liquid Scintillator and a Proportional Counter: Application to a Neutron Spectrum Similar to that from an Improvised Nuclear Device

    PubMed Central

    Randers-Pehrson, Gerhard; Marino, Stephen A.; Garty, Guy; Harken, Andrew; Brenner, David J.

    2015-01-01

    A novel neutron irradiation facility at the Radiological Research Accelerator Facility (RARAF) has been developed to mimic the neutron radiation from an Improvised Nuclear Device (IND) at relevant distances (e.g. 1.5 km) from the epicenter. The neutron spectrum of this IND-like neutron irradiator was designed according to estimations of the Hiroshima neutron spectrum at 1.5 km. It is significantly different from a standard reactor fission spectrum, because the spectrum changes as the neutrons are transported through air, and it is dominated by neutron energies from 100 keV up to 9 MeV. To verify such wide energy range neutron spectrum, detailed here is the development of a combined spectroscopy system. Both a liquid scintillator detector and a gas proportional counter were used for the recoil spectra measurements, with the individual response functions estimated from a series of Monte Carlo simulations. These normalized individual response functions were formed into a single response matrix for the unfolding process. Several accelerator-based quasi-monoenergetic neutron source spectra were measured and unfolded to test this spectroscopy system. These reference neutrons were produced from two reactions: T(p,n)3He and D(d,n)3He, generating neutron energies in the range between 0.2 and 8 MeV. The unfolded quasi-monoenergetic neutron spectra indicated that the detection system can provide good neutron spectroscopy results in this energy range. A broad-energy neutron spectrum from the 9Be(d,n) reaction using a 5 MeV deuteron beam, measured at 60 degrees to the incident beam was measured and unfolded with the evaluated response matrix. The unfolded broad neutron spectrum is comparable with published time-of-flight results. Finally, the pair of detectors were used to measure the neutron spectrum generated at the RARAF IND-like neutron facility and a comparison is made to the neutron spectrum of Hiroshima. PMID:26273118

  8. Broad Energy Range Neutron Spectroscopy using a Liquid Scintillator and a Proportional Counter: Application to a Neutron Spectrum Similar to that from an Improvised Nuclear Device.

    PubMed

    Xu, Yanping; Randers-Pehrson, Gerhard; Marino, Stephen A; Garty, Guy; Harken, Andrew; Brenner, David J

    2015-09-11

    A novel neutron irradiation facility at the Radiological Research Accelerator Facility (RARAF) has been developed to mimic the neutron radiation from an Improvised Nuclear Device (IND) at relevant distances (e.g. 1.5 km) from the epicenter. The neutron spectrum of this IND-like neutron irradiator was designed according to estimations of the Hiroshima neutron spectrum at 1.5 km. It is significantly different from a standard reactor fission spectrum, because the spectrum changes as the neutrons are transported through air, and it is dominated by neutron energies from 100 keV up to 9 MeV. To verify such wide energy range neutron spectrum, detailed here is the development of a combined spectroscopy system. Both a liquid scintillator detector and a gas proportional counter were used for the recoil spectra measurements, with the individual response functions estimated from a series of Monte Carlo simulations. These normalized individual response functions were formed into a single response matrix for the unfolding process. Several accelerator-based quasi-monoenergetic neutron source spectra were measured and unfolded to test this spectroscopy system. These reference neutrons were produced from two reactions: T(p,n)(3)He and D(d,n)(3)He, generating neutron energies in the range between 0.2 and 8 MeV. The unfolded quasi-monoenergetic neutron spectra indicated that the detection system can provide good neutron spectroscopy results in this energy range. A broad-energy neutron spectrum from the (9)Be(d,n) reaction using a 5 MeV deuteron beam, measured at 60 degrees to the incident beam was measured and unfolded with the evaluated response matrix. The unfolded broad neutron spectrum is comparable with published time-of-flight results. Finally, the pair of detectors were used to measure the neutron spectrum generated at the RARAF IND-like neutron facility and a comparison is made to the neutron spectrum of Hiroshima.

  9. Determination of radon-222 in ground water using liquid scintillation counting-survey of carefree cave-creek water basin in Arizona

    SciTech Connect

    Barnett, J.M.; McKlveen, J.W.; Hood, W.K. III

    1992-12-31

    Well water used in homes may contribute additional {sup 222}Rn to the indoor radon concentration. Our research objectives are to establish a method to measure radon in ground water using liquid scintillation (LS) spectrometry, and to determine the lung dose from the radon released into the air. The method involves collecting a nonaerated, slow, steady flow of water from a pumping well into a 437-mi (16-oz) glass bottle. A high meniscus assures no head space, and the sample is capped. In the laboratory, standard 22-ml LS glass vials are filled with 10 ml of a toluene-based, mineral oil, LS cocktail and two 5-ml sample aliquots. The vial is capped tightly, shaken vigorously, and placed in the LS counter. Equilibrium was established in about 3.5 h, after which samples were counted for 100 min each. Only radon and daughters were measured. According to NUREG/CR-4007, the lower limit of detection is 1.9 Bq L{sup -1} (51 pCi L{sup -1}) in the window of interest. The radon progeny detection efficiency was between 320 and 330% per unit radon activity (accounting for the detection efficiency of each alpha particle and the beta continuum), and the average background was approximately 6 counts per minute. We expect that wells containing radon concentrations between 100 and 1000 Bq L{sup -1} would produce an effective dose equivalent to the lungs of 0.4 to 0.7 mSv y{sup -1} (40-70 mrem y{sup -1}). Our study of 28 wells in Carefree-Cave Creek indicates that in 25% of the wells, radon levels were over 100 Bq L{sup -1} (2700 pCi L{sup -1}). Twelve wells were chosen for monthly monitoring to ensure the efficiency of the methodology. This simple method allows us to count a large number of samples over a short time period.

  10. A new value for the half-life of 10Be by Heavy-Ion Elastic Recoil Detection and liquid scintillation counting

    NASA Astrophysics Data System (ADS)

    Korschinek, G.; Bergmaier, A.; Faestermann, T.; Gerstmann, U. C.; Knie, K.; Rugel, G.; Wallner, A.; Dillmann, I.; Dollinger, G.; von Gostomski, Ch. Lierse; Kossert, K.; Maiti, M.; Poutivtsev, M.; Remmert, A.

    2010-01-01

    The importance of 10Be in different applications of accelerator mass spectrometry (AMS) is well-known. In this context the half-life of 10Be has a crucial impact, and an accurate and precise determination of the half-life is a prerequisite for many of the applications of 10Be in cosmic-ray and earth science research. Recently, the value of the 10Be half-life has been the centre of much debate. In order to overcome uncertainties inherent in previous determinations, we introduced a new method of high accuracy and precision. An aliquot of our highly enriched 10Be master solution was serially diluted with increasing well-known masses of 9Be. We then determined the initial 10Be concentration by least square fit to the series of measurements of the resultant 10Be/ 9Be ratio. In order to minimize uncertainties because of mass bias which plague other low-energy mass spectrometric methods, we used for the first time Heavy-Ion Elastic Recoil Detection (HI-ERD) for the determination of the 10Be/ 9Be isotopic ratios, a technique which does not suffer from difficult to control mass fractionation. The specific activity of the master solution was measured by means of accurate liquid scintillation counting (LSC). The resultant combination of the 10Be concentration and activity yields a 10Be half-life of T1/2 = 1.388 ± 0.018 (1 s, 1.30%) Ma. In a parallel but independent study (Chmeleff et al. [11]), found a value of 1.386 ± 0.016 (1.15%) Ma. Our recommended weighted mean and mean standard error for the new value for 10Be half-life based on these two independent measurements is 1.387 ± 0.012 (0.87%) Ma.

  11. Measurements of the response functions of a large size NE213 organic liquid scintillator for neutrons up to 800 MeV.

    PubMed

    Taniguchi, S; Moriya, T; Takada, M; Hatanaka, K; Wakasa, T; Saito, T

    2005-01-01

    The response functions of 25.4 cm (length) x 25.4 cm (diameter) NE213 organic liquid scintillator have been measured for neutrons in the energy range from 20 to 800 MeV at the Heavy-Ion Medical Accelerator in Chiba (HIMAC) and at the Research Center for Nuclear Physics (RCNP) of Osaka University. At HIMAC, white (continuous) energy spectrum neutrons were produced by the 400 MeV per nucleon carbon ion bombardment on a thick graphite target, whose energy spectrum has already been measured by Kurosawa et al., [Nucl. Sci. Eng. 132, 30 (1999)] and the response functions of the time-of-flight-gated monoenergetic neutrons in a wide energy range from 20 to 800 MeV were simultaneously measured. At RCNP, the quasi-monoenergetic neutrons were produced via 7Li(p,n)7Be reaction by 250 MeV proton beam bombardment on a thin 7Li target, and the TOF-gated 245 MeV peak neutrons were measured. The absolute peak neutron yield was obtained by the measurement of 478 keV gamma rays from the 7Be nuclei produced in a Li target. The measured results show that the response functions for monoenergetic neutrons < 250 MeV have a recoil proton plateau and an edge around the maximum light output, which increases with increasing incident neutron energy, on the other hand > 250 MeV, the plateau and the edge become unclear because the proton range becomes longer than the detector size and the escaping protons increase. It can be found that the efficiency of the 24.5 cm (diameter) x 25.4 cm (length) NE213 for the 250 MeV neutrons is -10 times larger than the 12.7 cm (length) x 12.7 cm (diameter) NE213, which is widely used as a neutron spectrometer.

  12. Measurement of light emission in scintillation vials

    SciTech Connect

    Duran Ramiro, M. Teresa; Garcia-Torano, Eduardo

    2005-09-15

    The efficiency and energy resolution of liquid scintillation counting (LSC) systems are strongly dependent on the optical characteristics of scintillators, vials, and reflectors. This article presents the results of measurements of the light-emission profile of scintillation vials. Two measurement techniques, autoradiographs and direct measurements with a photomultiplier tube, have been used to obtain light-emission distribution for standard vials of glass, etched glass and polyethylene. Results obtained with both techniques are in good agreement. For the first time, the effect of the meniscus in terms of light contribution has been numerically estimated. These results can help design LSC systems that are more efficient in terms of light collection.

  13. Measurement of the scintillation time spectra and pulse-shape discrimination of low-energy β and nuclear recoils in liquid argon with DEAP-1

    NASA Astrophysics Data System (ADS)

    Amaudruz, P.-A.; Batygov, M.; Beltran, B.; Bonatt, J.; Boudjemline, K.; Boulay, M. G.; Broerman, B.; Bueno, J. F.; Butcher, A.; Cai, B.; Caldwell, T.; Chen, M.; Chouinard, R.; Cleveland, B. T.; Cranshaw, D.; Dering, K.; Duncan, F.; Fatemighomi, N.; Ford, R.; Gagnon, R.; Giampa, P.; Giuliani, F.; Gold, M.; Golovko, V. V.; Gorel, P.; Grace, E.; Graham, K.; Grant, D. R.; Hakobyan, R.; Hallin, A. L.; Hamstra, M.; Harvey, P.; Hearns, C.; Hofgartner, J.; Jillings, C. J.; Kuźniak, M.; Lawson, I.; La Zia, F.; Li, O.; Lidgard, J. J.; Liimatainen, P.; Lippincott, W. H.; Mathew, R.; McDonald, A. B.; McElroy, T.; McFarlane, K.; McKinsey, D. N.; Mehdiyev, R.; Monroe, J.; Muir, A.; Nantais, C.; Nicolics, K.; Nikkel, J.; Noble, A. J.; O'Dwyer, E.; Olsen, K.; Ouellet, C.; Pasuthip, P.; Peeters, S. J. M.; Pollmann, T.; Rau, W.; Retière, F.; Ronquest, M.; Seeburn, N.; Skensved, P.; Smith, B.; Sonley, T.; Tang, J.; Vázquez-Jáuregui, E.; Veloce, L.; Walding, J.; Ward, M.

    2016-12-01

    The DEAP-1 low-background liquid argon detector was used to measure scintillation pulse shapes of electron and nuclear recoil events and to demonstrate the feasibility of pulse-shape discrimination down to an electron-equivalent energy of 20 keVee. In the surface dataset using a triple-coincidence tag we found the fraction of β events that are misidentified as nuclear recoils to be < 1.4 ×10-7 (90% C.L.) for energies between 43-86 keVee and for a nuclear recoil acceptance of at least 90%, with 4% systematic uncertainty on the absolute energy scale. The discrimination measurement on surface was limited by nuclear recoils induced by cosmic-ray generated neutrons. This was improved by moving the detector to the SNOLAB underground laboratory, where the reduced background rate allowed the same measurement to be done with only a double-coincidence tag. The combined data set contains 1.23 × 108 events. One of those, in the underground data set, is in the nuclear-recoil region of interest. Taking into account the expected background of 0.48 events coming from random pileup, the resulting upper limit on the level of electronic recoil contamination is < 2.7 ×10-8 (90% C.L.) between 44-89 keVee and for a nuclear recoil acceptance of at least 90%, with 6% systematic uncertainty on the absolute energy scale. We developed a general mathematical framework to describe pulse-shape-discrimination parameter distributions and used it to build an analytical model of the distributions observed in DEAP-1. Using this model, we project a misidentification fraction of approximately 10-10 for an electron-equivalent energy threshold of 15 keVee for a detector with 8 PE/keVee light yield. This reduction enables a search for spin-independent scattering of WIMPs from 1000 kg of liquid argon with a WIMP-nucleon cross-section sensitivity of 10-46 cm2, assuming negligible contribution from nuclear recoil backgrounds.

  14. Separation of scintillation and Cherenkov lights in linear alkyl benzene

    SciTech Connect

    Li, Mohan; Guo, Ziyi; Yeh, Minfang; Wang, Zhe; Chen, Shaomin

    2016-09-11

    To separate scintillation and Cherenkov lights in water-based liquid scintillator detectors is a desired feature for future neutrino and proton decay experiments. Linear alkyl benzene (LAB) is one important ingredient of a water-based liquid scintillator currently under development. In this paper we report on the separation of scintillation and Cherenkov lights observed in an LAB sample. The rise and decay times of the scintillation light are measured to be (7.7±3.0)ns and (36.6±2.4)ns, respectively, while the full width [–3σ, 3σ] of the Cherenkov light is 12 ns and is dominated by the time resolution of the photomultiplier tubes. Here, the scintillation light yield was measured to be(1.01±0.12)×103photons/MeV.

  15. Separation of scintillation and Cherenkov lights in linear alkyl benzene

    SciTech Connect

    Li, Mohan; Guo, Ziyi; Yeh, Minfang; Wang, Zhe; Chen, Shaomin

    2016-09-11

    To separate scintillation and Cherenkov lights in water-based liquid scintillator detectors is a desired feature for future neutrino and proton decay experiments. Linear alkyl benzene (LAB) is one important ingredient of a water-based liquid scintillator currently under development. In this paper we report on the separation of scintillation and Cherenkov lights observed in an LAB sample. The rise and decay times of the scintillation light are measured to be (7.7±3.0)ns and (36.6±2.4)ns, respectively, while the full width [–3σ, 3σ] of the Cherenkov light is 12 ns and is dominated by the time resolution of the photomultiplier tubes. Here, the scintillation light yield was measured to be(1.01±0.12)×103photons/MeV.

  16. Scintillators and applications thereof

    DOEpatents

    Williams, Richard T.

    2015-09-01

    Scintillators of various constructions and methods of making and using the same are provided. In some embodiments, a scintillator comprises at least one radiation absorption region and at least one spatially discrete radiative exciton recombination region.

  17. Scintillators and applications thereof

    DOEpatents

    Williams, Richard T.

    2014-07-15

    Scintillators of various constructions and methods of making and using the same are provided. In some embodiments, a scintillator comprises at least one radiation absorption region and at least one spatially discrete radiative exciton recombination region.

  18. High latitude scintillations

    NASA Astrophysics Data System (ADS)

    Basu, Santimay; Basu, Sunanda

    High-latitude phase and amplitude scintillations have been observed with quasi-geostationary polar beacon satellites, high-altitude orbiting GPS satellites, and low-altitude orbiting HiLat and Polar Bear satellites. The scintillation behavior observed in the polar cap, cusp, and nightside auroral oval is described. Consideration is given to the possible mechanisms for the generation of irregularities that cause scintillations. The importance of coordinated multitechnique measurements for scintillation studies is stressed.

  19. SNO+ Scintillator Purification and Assay

    NASA Astrophysics Data System (ADS)

    Ford, R.; Chen, M.; Chkvorets, O.; Hallman, D.; Vázquez-Jáuregui, E.

    2011-04-01

    We describe the R&D on the scintillator purification and assay methods and technology for the SNO+ neutrino and double-beta decay experiment. The SNO+ experiment is a replacement of the SNO heavy water with liquid scintillator comprised of 2 g/L PPO in linear alkylbenzene (LAB). During filling the LAB will be transported underground by rail car and purified by multi-stage distillation and steam stripping at a flow rate of 19 LPM. While the detector is operational the scintillator can be recirculated at 150 LPM (full detector volume in 4 days) to provide repurification as necessary by either water extraction (for Ra, K, Bi) or by functional metal scavenger columns (for Pb, Ra, Bi, Ac, Th) followed by steam stripping to remove noble gases and oxygen (Rn, O2, Kr, Ar). The metal scavenger columns also provide a method for scintillator assay for ex-situ measurement of the U and Th chain radioactivity. We have developed "natural" radioactive spikes of Pb and Ra in LAB and use these for purification testing. Lastly, we present the planned operating modes and purification strategies and the plant specifications and design.

  20. SNO+ Scintillator Purification and Assay

    SciTech Connect

    Ford, R.; Vazquez-Jauregui, E.; Chen, M.; Chkvorets, O.; Hallman, D.

    2011-04-27

    We describe the R and D on the scintillator purification and assay methods and technology for the SNO+ neutrino and double-beta decay experiment. The SNO+ experiment is a replacement of the SNO heavy water with liquid scintillator comprised of 2 g/L PPO in linear alkylbenzene (LAB). During filling the LAB will be transported underground by rail car and purified by multi-stage distillation and steam stripping at a flow rate of 19 LPM. While the detector is operational the scintillator can be recirculated at 150 LPM (full detector volume in 4 days) to provide repurification as necessary by either water extraction (for Ra, K, Bi) or by functional metal scavenger columns (for Pb, Ra, Bi, Ac, Th) followed by steam stripping to remove noble gases and oxygen (Rn, O{sub 2}, Kr, Ar). The metal scavenger columns also provide a method for scintillator assay for ex-situ measurement of the U and Th chain radioactivity. We have developed ''natural'' radioactive spikes of Pb and Ra in LAB and use these for purification testing. Lastly, we present the planned operating modes and purification strategies and the plant specifications and design.

  1. Scintillator manufacture at Fermilab

    SciTech Connect

    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.

  2. Lead carbonate scintillator materials

    DOEpatents

    Derenzo, Stephen E.; Moses, William W.

    1991-01-01

    Improved radiation detectors containing lead carbonate or basic lead carbonate as the scintillator element are disclosed. Both of these scintillators have been found to provide a balance of good stopping power, high light yield and short decay constant that is superior to other known scintillator materials. The radiation detectors disclosed are favorably suited for use in general purpose detection and in medical uses.

  3. Scintillator materials for calorimetry

    SciTech Connect

    Weber, M.J.

    1994-09-01

    Requirements for fast, dense scintillator materials for calorimetry in high energy physics and approaches to satisfying these requirements are reviewed with respect to possible hosts and luminescent species. Special attention is given to cerium-activated crystals, core-valence luminescence, and glass scintillators. The present state of the art, limitations, and suggestions for possible new scintillator materials are presented.

  4. Scintillator manufacture at Fermilab

    NASA Astrophysics Data System (ADS)

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

    1998-11-01

    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.

  5. Scintillator reflective layer coextrusion

    DOEpatents

    Yun, Jae-Chul; Para, Adam

    2001-01-01

    A polymeric scintillator has a reflective layer adhered to the exterior surface thereof. The reflective layer comprises a reflective pigment and an adhesive binder. The adhesive binder includes polymeric material from which the scintillator is formed. A method of forming the polymeric scintillator having a reflective layer adhered to the exterior surface thereof is also provided. The method includes the steps of (a) extruding an inner core member from a first amount of polymeric scintillator material, and (b) coextruding an outer reflective layer on the exterior surface of the inner core member. The outer reflective layer comprises a reflective pigment and a second amount of the polymeric scintillator material.

  6. Synthesis of plastic scintillation microspheres: Evaluation of scintillators

    NASA Astrophysics Data System (ADS)

    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 3H, 51.2% for 14C, 180.6% for 90Sr/90Y and 76.7% for 241Am. 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 of

  7. Characterization of the scintillation anisotropy in crystalline stilbene scintillator detectors

    SciTech Connect

    Schuster, P.; Brubaker, E.

    2016-11-23

    This study reports a series of measurements that characterize the directional dependence of the scintillation response of crystalline melt-grown and solution-grown trans-stilbene to incident DT and DD neutrons. These measurements give the amplitude and pulse shape dependence on the proton recoil direction over one hemisphere of the crystal, confirming and extending previous results in the literature for melt-grown stilbene and providing the first measurements for solution-grown stilbene. In similar measurements of liquid and plastic detectors, no directional dependence was observed, confirming the hypothesis that the anisotropy in stilbene and other organic crystal scintillators is a result of internal effects due to the molecular or crystal structure and not an external effect on the measurement system.

  8. Characterization of the scintillation anisotropy in crystalline stilbene scintillator detectors

    DOE PAGES

    Schuster, P.; Brubaker, E.

    2016-11-23

    This study reports a series of measurements that characterize the directional dependence of the scintillation response of crystalline melt-grown and solution-grown trans-stilbene to incident DT and DD neutrons. These measurements give the amplitude and pulse shape dependence on the proton recoil direction over one hemisphere of the crystal, confirming and extending previous results in the literature for melt-grown stilbene and providing the first measurements for solution-grown stilbene. In similar measurements of liquid and plastic detectors, no directional dependence was observed, confirming the hypothesis that the anisotropy in stilbene and other organic crystal scintillators is a result of internal effects duemore » to the molecular or crystal structure and not an external effect on the measurement system.« less

  9. Characterization of the scintillation anisotropy in crystalline stilbene scintillator detectors

    NASA Astrophysics Data System (ADS)

    Schuster, P.; Brubaker, E.

    2017-07-01

    This paper reports a series of measurements that characterize the directional dependence of the scintillation response of crystalline melt-grown and solution-grown trans-stilbene to incident DT and DD neutrons. These measurements give the amplitude and pulse shape dependence on the proton recoil direction over one hemisphere of the crystal, confirming and extending previous results in the literature for melt-grown stilbene and providing the first measurements for solution-grown stilbene. In similar measurements of liquid and plastic detectors, no directional dependence was observed, confirming the hypothesis that the anisotropy in stilbene and other organic crystal scintillators is a result of internal effects due to the molecular or crystal structure and not an external effect on the measurement system.

  10. Development of a quasi-monoenergetic neutron field and measurements of the response function of an organic liquid scintillator for the neutron energy range from 66 to 206 MeV

    NASA Astrophysics Data System (ADS)

    Nakao, Noriaki; Kurosawa, Tadahiro; Nakamura, Takashi; Uwamino, Yoshitomo

    2002-01-01

    A quasi-monoenergetic neutron field was developed using a thin 7Li target bombarded by protons in the energy range from 70 to 210 MeV at the RIKEN ring cyclotron facility. The neutron energy spectra were measured with an NE213 organic liquid scintillator using the TOF method. The absolute peak neutron yields were obtained by measurements of 478 keV γ-rays from 7Be nuclei produced in a 7Li target through the 7Li( p,n) 7Be (g.s.+0.429 MeV) reaction. Using the neutron field, the absolute values of the neutron response functions of a 12.7 cm diameter by 12.7 cm long NE213 organic liquid scintillator were measured, and were compared with calculations using a Monte Carlo code developed by Cecil et al. The measured response functions without any wall-effect events were also obtained, and compared with calcualtions using a modified Monte Carlo code. Comparisons between a measurement and a calculation both with and without any wall-effect events gave a good agreement.

  11. Real-time volumetric scintillation dosimetry

    NASA Astrophysics Data System (ADS)

    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.

  12. Properties of scintillator solutes

    SciTech Connect

    Fluornoy, J.M.

    1998-06-01

    This special report summarizes measurements of the spectroscopic and other properties of the solutes that were used in the preparation of several new liquid scintillators developed at EG and G/Energy Measurements/Santa Barbara Operations (the precursor to Bechtel Nevada/Special Technologies Laboratory) on the radiation-to-light converter program. The data on the individual compounds are presented in a form similar to that used by Prof. Isadore Berlman in his classic handbook of fluorescence spectra. The temporal properties and relative efficiencies of the new scintillators are presented in Table 1, and the efficiencies as a function of wavelength are presented graphically in Figure 1. In addition, there is a descriptive glossary of the abbreviations used herein. Figure 2 illustrates the basic structures of some of the compounds and of the four solvents reported in this summary. The emission spectra generally exhibit more structure than the absorption spectra, with the result that the peak emission wavelength for a given compound may lie several nm away from the wavelength, {lambda}{sub avg}, at the geometric center of the emission spectrum. Therefore, the author has chosen to list absorption peaks, {lambda}{sub max}, and emission {lambda}{sub avg} values in Figures 3--30, as being most illustrative of the differences between the compounds. The compounds, BHTP, BTPB, ADBT, and DPTPB were all developed on this program. P-terphenyl, PBD, and TPB are commercially available blue emitters. C-480 and the other longer-wavelength emitters are laser dyes available commercially from Exciton Corporation. 1 ref., 30 figs.

  13. Composite solid-state scintillators for neutron detection

    DOEpatents

    Dai, Sheng; Im, Hee-Jung; Pawel, Michelle D.

    2006-09-12

    Applicant's present invention is a composite scintillator for neutron detection comprising a matrix material fabricated from an inorganic sol-gel precursor solution homogeneously doped with a liquid scintillating material and a neutron absorbing material. The neutron absorbing material yields at least one of an electron, a proton, a triton, an alpha particle or a fission fragment when the neutron absorbing material absorbs a neutron. The composite scintillator further comprises a liquid scintillating material in a self-assembled micelle formation homogeneously doped in the matrix material through the formation of surfactant-silica composites. The scintillating material is provided to scintillate when traversed by at least one of an electron, a proton, a triton, an alpha particle or a fission fragment. The scintillating material is configured such that the matrix material surrounds the micelle formation of the scintillating material. The composite scintillator is fabricated and applied as a thin film on substrate surfaces, a coating on optical fibers or as a glass material.

  14. The XENON100 Dark Matter Experiment: Design, Construction, Calibration and 2010 Search Results with Improved Measurement of the Scintillation Response of Liquid Xenon to Low-Energy Nuclear Recoils

    NASA Astrophysics Data System (ADS)

    Plante, Guillaume

    An impressive array of astrophysical observations suggest that 83% of the matter in the universe is in a form of non-luminous, cold, collisionless, non-baryonic dark matter. Several extensions of the Standard Model of particle physics aimed at solving the hierarchy problem predict stable weakly interacting massive particles (WIMPs) that could naturally have the right cosmological relic abundance today to compose most of the dark matter if their interactions with normal matter are on the order of a weak scale cross section. These candidates also have the added benefit that their properties and interaction rates can be computed in a well defined particle physics model. A considerable experimental effort is currently under way to uncover the nature of dark matter. One method of detecting WIMP dark matter is to look for its interactions in terrestrial detectors where it is expected to scatter off nuclei. In 2007, the XENON10 experiment took the lead over the most sensitive direct detection dark matter search in operation, the CDMS II experiment, by probing spin-independent WIMP-nucleon interaction cross sections down to sigmachi N ˜ 5 x 10-44 cm 2 at 30 GeV/c2. Liquefied noble gas detectors are now among the technologies at the forefront of direct detection experiments. Liquid xenon (LXe), in particular, is a well suited target for WIMP direct detection. It is easily scalable to larger target masses, allows discrimination between nuclear recoils and electronic recoils, and has an excellent stopping power to shield against external backgrounds. A particle losing energy in LXe creates both ionization electrons and scintillation light. In a dual-phase LXe time projection chamber (TPC) the ionization electrons are drifted and extracted into the gas phase where they are accelerated to amplify the charge signal into a proportional scintillation signal. These two signals allow the three-dimensional localization of events with millimeter precision and the ability to

  15. Subnanosecond Scintillation Detector

    NASA Technical Reports Server (NTRS)

    Hoenk, Michael (Inventor); Hennessy, John (Inventor); Hitlin, David (Inventor)

    2017-01-01

    A scintillation detector, including a scintillator that emits scintillation; a semiconductor photodetector having a surface area for receiving the scintillation, wherein the surface area has a passivation layer configured to provide a peak quantum efficiency greater than 40% for a first component of the scintillation, and the semiconductor photodetector has built in gain through avalanche multiplication; a coating on the surface area, wherein the coating acts as a bandpass filter that transmits light within a range of wavelengths corresponding to the first component of the scintillation and suppresses transmission of light with wavelengths outside said range of wavelengths; and wherein the surface area, the passivation layer, and the coating are controlled to increase the temporal resolution of the semiconductor photodetector.

  16. Shifting scintillator neutron detector

    DOEpatents

    Clonts, Lloyd G; Cooper, Ronald G; Crow, Jr., Morris Lowell; Hannah, Bruce W; Hodges, Jason P; Richards, John D; Riedel, Richard A

    2014-03-04

    Provided are sensors and methods for detecting thermal neutrons. Provided is an apparatus having a scintillator for absorbing a neutron, the scintillator having a back side for discharging a scintillation light of a first wavelength in response to the absorbed neutron, an array of wavelength-shifting fibers proximate to the back side of the scintillator for shifting the scintillation light of the first wavelength to light of a second wavelength, the wavelength-shifting fibers being disposed in a two-dimensional pattern and defining a plurality of scattering plane pixels where the wavelength-shifting fibers overlap, a plurality of photomultiplier tubes, in coded optical communication with the wavelength-shifting fibers, for converting the light of the second wavelength to an electronic signal, and a processor for processing the electronic signal to identify one of the plurality of scattering plane pixels as indicative of a position within the scintillator where the neutron was absorbed.

  17. Real-time, digital pulse-shape discrimination in non-hazardous fast liquid scintillation detectors: Prospects for safety and security

    SciTech Connect

    Joyce, M. J.; Aspinall, M. D.; Cave, F. D.; Lavietes, A. D.

    2011-07-01

    Pulse-shape discrimination (PSD) in fast, organic scintillation detectors is a long-established technique used to separate neutrons and {gamma} rays in mixed radiation fields. In the analogue domain the method can achieve separation in real time, but all knowledge of the pulses themselves is lost thereby preventing the possibility of any post- or repeated analysis. Also, it is typically reliant on electronic systems that are largely obsolete and which require significant experience to set up. In the digital domain, PSD is often more flexible but significant post-processing has usually been necessary to obtain neutron/{gamma}-ray separation. Moreover, the scintillation media on which the technique relies usually have a low flash point and are thus deemed hazardous. This complicates the ease with which they are used in industrial applications. In this paper, results obtained with a new portable digital pulse-shape discrimination instrument are described. This instrument provides real-time, digital neutron/{gamma} separation whilst preserving the synchronization with the time-of-arrival for each event, and realizing throughputs of 3 x 10{sup 6} events per second. Furthermore, this system has been tested with a scintillation medium that is non-flammable and not hazardous. (authors)

  18. Separation of scintillation and Cherenkov lights in linear alkyl benzene

    DOE PAGES

    Li, Mohan; Guo, Ziyi; Yeh, Minfang; ...

    2016-09-11

    To separate scintillation and Cherenkov lights in water-based liquid scintillator detectors is a desired feature for future neutrino and proton decay experiments. Linear alkyl benzene (LAB) is one important ingredient of a water-based liquid scintillator currently under development. In this paper we report on the separation of scintillation and Cherenkov lights observed in an LAB sample. The rise and decay times of the scintillation light are measured to be (7.7±3.0)ns and (36.6±2.4)ns, respectively, while the full width [–3σ, 3σ] of the Cherenkov light is 12 ns and is dominated by the time resolution of the photomultiplier tubes. Here, the scintillationmore » light yield was measured to be(1.01±0.12)×103photons/MeV.« less

  19. Study of equatorial scintillations

    NASA Technical Reports Server (NTRS)

    Pomalaza, J.; Woodman, R.; Tisnado, G.; Nakasone, E.

    1972-01-01

    Observations of the amplitude scintillations produced by the F-region in equatorial areas are presented. The equipment used for conducting the observations is described. The use of transmissions from the ATS-1, ATS-3, and ATS-5 for obtaining data is described. The two principal subjects discussed are: (1) correlation between satellite and incoherent radar observations of scintillations and (2) simultaneous observations of scintillations at 136 MHz and 1550 MHz.

  20. Lead carbonate scintillator materials

    DOEpatents

    Derenzo, S.E.; Moses, W.W.

    1991-05-14

    Improved radiation detectors containing lead carbonate or basic lead carbonate as the scintillator element are disclosed. Both of these scintillators have been found to provide a balance of good stopping power, high light yield and short decay constant that is superior to other known scintillator materials. The radiation detectors disclosed are favorably suited for use in general purpose detection and in medical uses. 3 figures.

  1. The SNO+ Scintillator Purification Plant and Projected Sensitivity to Solar Neutrinos in the Pure Scintillator Phase

    NASA Astrophysics Data System (ADS)

    Pershing, Teal; SNO+ Collaboration

    2016-03-01

    The SNO+ detector is a neutrino and neutrinoless double-beta decay experiment utilizing the renovated SNO detector. In the second phase of operation, the SNO+ detector will contain 780 tons of organic liquid scintillator composed of 2 g/L 2,5-diphenyloxazole (PPO) in linear alkylbenzene (LAB). In this phase, SNO+ will strive to detect solar neutrinos in the sub-MeV range, including CNO production neutrinos and pp production neutrinos. To achieve the necessary detector sensitivity, a four-part scintillator purification plant has been constructed in SNOLAB for the removal of ionic and radioactive impurities. We present an overview of the SNO+ scintillator purification plant stages, including distillation, water extraction, gas stripping, and metal scavenger columns. We also give the projected SNO+ sensitivities to various solar-produced neutrinos based on the scintillator plant's projected purification efficiency.

  2. Energy Transfer Based Nanocomposite Scintillator for Radiation Detection

    NASA Astrophysics Data System (ADS)

    Aslam, Soha; Sahi, Sunil; Chen, Wei; Ma, Lun; Kenarangui, Rasool

    2014-09-01

    Scintillators are the materials that emit light upon irradiation with high energy radiation like X-ray or gamma-ray. Inorganic single crystal and organic (plastic and liquid) are the two most used scintillator types. Both of these scintillator kinds have advantages and disadvantages. Inorganic single crystals are expensive and difficult to grow in desire shape and size. Also, single crystal scintillator such as NaI and CsI are very hygroscopic. On the other hand, organic scintillators have low density which limits their applications in gamma spectroscopy. Due to high quantum yield and size dependent emission, nanoparticles have attracted interested in various field of research. Here, we have studies the nanoparticles for radiation detection. We have synthesized nanoparticles of Cerium fluoride (CeF3), Zinc Oxide (ZnO), Cadmium Telluride (CdTe), Copper complex and Zinc sulfide (ZnS). We have used Fluorescence Resonance Energy Transfer (FRET) principle to enhance the luminescence properties of nanocomposite scintillator. Nanocomposites scintillators are structurally characterized with X-ray diffraction (XRD) and Transmission Electron Microscopy (TEM). Optical properties are studied using Photoluminescence, UV-Visible and X-ray. Enhancements in the luminescence are observed under UV and X-ray excitation. Preliminary studies shows nanocomposite scintillators are promising for radiation detection. Scintillators are the materials that emit light upon irradiation with high energy radiation like X-ray or gamma-ray. Inorganic single crystal and organic (plastic and liquid) are the two most used scintillator types. Both of these scintillator kinds have advantages and disadvantages. Inorganic single crystals are expensive and difficult to grow in desire shape and size. Also, single crystal scintillator such as NaI and CsI are very hygroscopic. On the other hand, organic scintillators have low density which limits their applications in gamma spectroscopy. Due to high quantum

  3. Comparison of the absorption of micronized (Daflon 500 mg) and nonmicronized 14C-diosmin tablets after oral administration to healthy volunteers by accelerator mass spectrometry and liquid scintillation counting.

    PubMed

    Garner, R C; Garner, J V; Gregory, S; Whattam, M; Calam, A; Leong, D

    2002-01-01

    Daflon 500 mg, is a micronized purified flavonoid fraction, containing 90% w/w diosmin and 10% w/w of flavonoids expressed as hesperidin, used clinically in the treatment of chronic venous insufficiency and hemorrhoidal disease. This study was designed to investigate the influence of particle size on the overall absorption of diosmin after oral administration of micronized (mean particle size = 1.79 microm, with 80% of particles having a size lower than 3.45 microm) and nonmicronized diosmin (mean particle size = 36.5 microm, with 80% of particles comprised between 19.9 and 159 microm). In a double blinded, cross-over study design, 500 mg tablets containing trace amounts (approximately 25 nCi) of (14)C-diosmin were administered to 12 healthy male volunteers as a single oral dose. Accelerator mass spectrometry and liquid scintillation counting were used for the measurement of (14)C-diosmin in urine and feces. Absorption of (14)C-diosmin from the gastrointestinal tract, measured by the urinary excretion of total radioactivity, was significantly improved with the micronized (57.9 +/- 20.2%) compared with the nonmicronized material (32.7 +/- 18.8%). Statistical comparison of the urinary excretion of the two pharmaceutical formulations showed this difference to be highly significant (p = 0.0004, analysis of variance). The overall excretion of the radiolabeled dose was 100% with mean +/- SD of 109 +/- 23% and 113 +/- 20% for the micronized and nonmicronized forms, respectively. The results of this study show: 1. the impact of a reduction of particle size on the extent of absorption of diosmin, giving a pharmacokinetic explanation to the better clinical efficacy observed with the micronized formulation, and 2. the use of accelerator mass spectrometry in conjunction with liquid scintillation counting in measurement of bioavailability in a human cross-over study comparing two drug formulations containing trace amounts of radioactivity. Copyright 2002 Wiley-Liss, Inc.

  4. Improvements in apparatus and procedures for using an organic liquid scintillator as a fast-neutron spectrometer for radiation protection applications

    SciTech Connect

    Thorngate, J.H.

    1987-05-15

    For use in radiation protection measurements, a neutron spectrometer must have a wide energy range, good sensitivity, medium resolution, and ease of taking and reducing data. No single spectrometer meets all of these requirements. Several experiments aimed at improving and characterizing the detector response to gamma rays and neutrons were conducted. A light pipe (25 mm) was needed between the scintillator cell and the photomultiplier tube to achieve the best resolution. The light output of the scintillator as a function of gamma-ray energy was measured. Three experiments were conducted to determine the light output as a function of neutron energy. Monte Carlo calculations were made to evaluate the effects of multiple neutron scattering and edge effects in the detector. The electronic systems associated with the detector were improved with a transistorized circuit providing the bias voltage for the photomultiplier tube dynodes. This circuit was needed to obtain pulse-height linearity over the wide range of signal sizes. A special live-time clock was built to compensate for the large amount of dead time generated by the pulse-shape discrimination circuit we chose to use. 64 refs., 58 figs., 9 tabs.

  5. Scintillation properties of polycrystalline LaxY1-xO3 ceramic

    NASA Astrophysics Data System (ADS)

    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.

  6. Thin film scintillators

    NASA Astrophysics Data System (ADS)

    McDonald, Warren; McKinney, George; Tzolov, Marian

    2015-03-01

    Scintillating materials convert energy flux (particles or electromagnetic waves) into light with spectral characteristic matching a subsequent light detector. Commercial scintillators such as yttrium aluminum garnet (YAG) and yttrium aluminum perovskite (YAP) are commonly used. These are inefficient at lower energies due to the conductive coating present on their top surface, which is needed to avoid charging. We hypothesize that nano-structured thin film scintillators will outperform the commercial scintillators at low electron energies. We have developed alternative thin film scintillators, zinc tungstate and zinc oxide, which show promise for higher sensitivity to lower energy electrons since they are inherently conductive. Zinc tungstate films exhibit photoluminescence quantum efficiency of 74%. Cathodoluminescence spectroscopy was applied in transmission and reflection geometries. The comparison between the thin films and the YAG and YAP commercial scintillators shows much higher light output from the zinc tungstate and zinc oxide at electron energies less than 5 keV. Our films were integrated in a backscattered electron detector. This detector delivers better images than an identical detector with commercial YAG scintillator at low electron energies. Dr. Nicholas Barbi from PulseTor LLC, Dr. Anura Goonewardene, NSF Grants: #0806660, #1058829, #0923047.

  7. DETECTORS AND EXPERIMENTAL METHODS: Measurement of the response function and the detection efficiency of an organic liquid scintillator for neutrons between 1 and 30 MeV

    NASA Astrophysics Data System (ADS)

    Huang, Han-Xiong; Ruan, Xi-Chao; Chen, Guo-Chang; Zhou, Zu-Ying; Li, Xia; Bao, Jie; Nie, Yang-Bo; Zhong, Qi-Ping

    2009-08-01

    The light output function of a varphi50.8 mm × 50.8 mm BC501A scintillation detector was measured in the neutron energy region of 1 to 30 MeV by fitting the pulse height (PH) spectra for neutrons with the simulations from the NRESP code at the edge range. Using the new light output function, the neutron detection efficiency was determined with two Monte-Carlo codes, NEFF and SCINFUL. The calculated efficiency was corrected by comparing the simulated PH spectra with the measured ones. The determined efficiency was verified at the near threshold region and normalized with a Proton-Recoil-Telescope (PRT) at the 8-14 MeV energy region.

  8. Synthesis and characterization of nanocomposite scintillators for radiation detection

    NASA Astrophysics Data System (ADS)

    Sahi, Sunil Kumar

    Inorganic single crystal and organic (plastic and liquid) scintillators are commonly used for radiation detection. Inorganic single crystals are efficient and have better energy resolution compared to organic scintillators. However, inorganic single crystals are difficult to grow in large size and hence expensive. On the other hand, fast decay time and ease of fabrication makes organic scintillators attractive for many applications. However, poor energy resolution of organic scintillators limits its applications in gamma ray spectroscopy. The poor energy resolution is due to the low Z-value and low density of organic scintillator. The Z-value of organic plastic scintillator can be increase by loading nanoparticles in plastic matrix. It is expected that the increase in Z-value would result in improve energy resolution of nanocomposite scintillator. However, the loss of optical transparency due to nanoparticles loading is one of the major concerns of nanocomposite scintillators. In this dissertation, we used different methods to synthesize La xCe1-xF3 nanoparticles with high dispersion in polymer matrix. High nanoparticle dispersion is important to load high concentration of nanoparticles into polymer matrix without losing the transparency of the polymer matrix. The as synthesized nanoparticles are dispersed into monomers and polymerized using heat initiated bulk polymerization method. Nanoparticles are characterized using TEM, XRD, FTIR and TGA. The optical and scintillation properties of nanoparticles and nanocomposites are studied using spectroscopic techniques. The pulse height spectra obtained using nanocomposite fabricated by loading up to 30 wt% nanoparticles clearly show a photopeak for the 122 keV line of the Co-57 isotope. The generation of the photopeak is due to the enhanced photoelectric effect as a result of increased effective atomic number (Zeff) and density of nanocomposite scintillator. The pulse height spectra of Cs-137 gamma source show a full

  9. Segmented scintillation antineutrino detector

    DOEpatents

    Reyna, David

    2017-05-09

    The various technologies presented herein relate to incorporating a wavelength-shifting material in a scintillator to facilitate absorption of a first electromagnetic particle (e.g., a first photon) having a first wavelength and subsequent generation and emission of a second electromagnetic particle (e.g., a second photon) having a second wavelength. The second electromagnetic particle can be emitted isotropically, with a high probability that the direction of emission of the second electromagnetic particle is disparate to the direction of travel of the first electromagnetic particle (and according angle of incidence). Isotropic emission of the second electromagnetic particle enables the second electromagnetic particle to be retained in the scintillator owing to internal reflection. Accordingly, longer length scintillators can be constructed, and accordingly, the scintillator array has a greater area (and volume) over which to detect electromagnetic particles (e.g., antineutrinos) being emitted from a nuclear reaction.

  10. Scintillating pad detectors

    SciTech Connect

    Adams, D.; Baumbaugh, B.; Borcherding, F.

    1996-12-31

    We have been investigating the performance of scintillating pad detectors, individual small tiles of scintillator that are read out with wavelength-shifting fibers and visible light photon counters, for application in high luminosity colliding beam experiments such as the D0 Upgrade. Such structures could provide {open_quotes}pixel{close_quotes} type readout over large fiducial volumes for tracking, preshower detection and triggering.

  11. Probing Cherenkov and Scintillation Light Separation for Next-Generation Neutrino Detectors

    NASA Astrophysics Data System (ADS)

    Caravaca, J.; Descamps, F. B.; Land, B. J.; Orebi Gann, G. D.; Wallig, J.; Yeh, M.

    2017-09-01

    The ability to separate Cherenkov and scintillation signals in liquid scintillator detectors would enable outstanding background rejection for next-generation neutrino experiments. Reconstruction of directional information, ring imaging, and sub-Cherenkov threshold detection all have the potential to substantially improve particle and event identification. The Cherenkov-Scintillation Separation (CHESS) experiment uses an array of small, fast photomultipliers (PMTs) and state-of-the-art electronics to demonstrate the reconstruction of a Cherenkov ring in a scintillation medium based on photon hit times and detected charge. This setup has been used to characterize the ability to detect Cherenkov light in a range of target media. We show results with pure organic scintillator (LAB) and the prospects with scintillators with a secondary fluor (LAB/PPO). There are future plans to deploy the newly developed water-based liquid scintillator, a medium with a higher Cherenkov/Scintillation light yield ratio than conventional pure liquid scintillators, enhancing the visibility of the less abundant Cherenkov light in the presence of scintillation light. These results can inform the development of future large-scale detectors, such as the proposed Theia experiment, or other large detectors at underground laboratories such as the far-site of the new Long Baseline Neutrino Facility at the Sanford Underground Research Facility. CHESS detector calibrations and commissioning will be discussed, and the latest results will be presented.

  12. Ionospheric Scintillation Explorer (ISX)

    NASA Astrophysics Data System (ADS)

    Iuliano, J.; Bahcivan, H.

    2015-12-01

    NSF has recently selected Ionospheric Scintillation Explorer (ISX), a 3U Cubesat mission to explore the three-dimensional structure of scintillation-scale ionospheric irregularities associated with Equatorial Spread F (ESF). ISX is a collaborative effort between SRI International and Cal Poly. This project addresses the science question: To what distance along a flux tube does an irregularity of certain transverse-scale extend? It has been difficult to measure the magnetic field-alignment of scintillation-scale turbulent structures because of the difficulty of sampling a flux tube at multiple locations within a short time. This measurement is now possible due to the worldwide transition to DTV, which presents unique signals of opportunity for remote sensing of ionospheric irregularities from numerous vantage points. DTV spectra, in various formats, contain phase-stable, narrowband pilot carrier components that are transmitted simultaneously. A 4-channel radar receiver will simultaneously record up to 4 spatially separated transmissions from the ground. Correlations of amplitude and phase scintillation patterns corresponding to multiple points on the same flux tube will be a measure of the spatial extent of the structures along the magnetic field. A subset of geometries where two or more transmitters are aligned with the orbital path will be used to infer the temporal development of the structures. ISX has the following broad impact. Scintillation of space-based radio signals is a space weather problem that is intensively studied. ISX is a step toward a CubeSat constellation to monitor worldwide TEC variations and radio wave distortions on thousands of ionospheric paths. Furthermore, the rapid sampling along spacecraft orbits provides a unique dataset to deterministically reconstruct ionospheric irregularities at scintillation-scale resolution using diffraction radio tomography, a technique that enables prediction of scintillations at other radio frequencies, and

  13. Scintillator plate calorimetry

    SciTech Connect

    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.

  14. Improvement of the Eakins and Brown method for measuring 59Fe and 55Fe in blood and other iron-containing materials by liquid scintillation counting and sample preparation using microwave digestion and ion-exchange column purification of iron.

    PubMed

    Viteri, F E; Kohaut, B A

    1997-01-01

    The simultaneous measurement of 59Fe and 55Fe in whole blood by liquid scintillation counting by the Eakins and Brown (EB) method is extensively used in iron absorption studies. The EB method requires many steps which increase the chances of error and decrease its sensitivity. We describe two modifications to the above method consisting of microwave digestion and column purification of iron. This "New Method" (NM) is simpler and more precise, and sensitive than the EB method. Counting efficiencies with the NM are similar for 59Fe (75%) as with the EB method but are better for 55Fe (29% for NM vs 22%), and cross counting from 59Fe into the 55Fe window is lower with the NM (3.7-4.5%) than with the EB method (10-12%). For the NM, recoveries of radioactive blood samples, in relation to processed standards ranged from 100 to 103% for 59Fe and 101 to 113% for 55Fe. For the EB method, recoveries ranged from 94 to 99% for 59Fe and from 88 to 93% for 55Fe. Even with very low counts, average intrarun CV with the NM was lower than 5.4% for either isotope, while it was as high as 10.0% for 55Fe with the EB method.

  15. A scintillator purification plant and fluid handling system for SNO+

    NASA Astrophysics Data System (ADS)

    Ford, Richard J.

    2015-08-01

    A large capacity purification plant and fluid handling system has been constructed for the SNO+ neutrino and double-beta decay experiment, located 6800 feet underground at SNOLAB, Canada. SNO+ is a refurbishment of the SNO detector to fill the acrylic vessel with liquid scintillator based on Linear Alkylbenzene (LAB) and 2 g/L PPO, and also has a phase to load natural tellurium into the scintillator for a double-beta decay experiment with 130Te. The plant includes processes multi-stage dual-stream distillation, column water extraction, steam stripping, and functionalized silica gel adsorption columns. The plant also includes systems for preparing the scintillator with PPO and metal-loading the scintillator for double-beta decay exposure. We review the basis of design, the purification principles, specifications for the plant, and the construction and installations. The construction and commissioning status is updated.

  16. A scintillator purification plant and fluid handling system for SNO+

    SciTech Connect

    Ford, Richard J.

    2015-08-17

    A large capacity purification plant and fluid handling system has been constructed for the SNO+ neutrino and double-beta decay experiment, located 6800 feet underground at SNOLAB, Canada. SNO+ is a refurbishment of the SNO detector to fill the acrylic vessel with liquid scintillator based on Linear Alkylbenzene (LAB) and 2 g/L PPO, and also has a phase to load natural tellurium into the scintillator for a double-beta decay experiment with {sup 130}Te. The plant includes processes multi-stage dual-stream distillation, column water extraction, steam stripping, and functionalized silica gel adsorption columns. The plant also includes systems for preparing the scintillator with PPO and metal-loading the scintillator for double-beta decay exposure. We review the basis of design, the purification principles, specifications for the plant, and the construction and installations. The construction and commissioning status is updated.

  17. Scintillator Waveguide For Sensing Radiation

    DOEpatents

    Bliss, Mary; Craig, Richard A.; Reeder; Paul L.

    2003-04-22

    The present invention is an apparatus for detecting ionizing radiation, having: a waveguide having a first end and a second end, the waveguide formed of a scintillator material wherein the therapeutic ionizing radiation isotropically generates scintillation light signals within the waveguide. This apparatus provides a measure of radiation dose. The apparatus may be modified to permit making a measure of location of radiation dose. Specifically, the scintillation material is segmented into a plurality of segments; and a connecting cable for each of the plurality of segments is used for conducting scintillation signals to a scintillation detector.

  18. Scintillator requirements for medical imaging

    SciTech Connect

    Moses, William W.

    1999-09-01

    Scintillating materials are used in a variety of medical imaging devices. This paper presents a description of four medical imaging modalities that make extensive use of scintillators: planar x-ray imaging, x-ray computed tomography (x-ray CT), SPECT (single photon emission computed tomography) and PET (positron emission tomography). The discussion concentrates on a description of the underlying physical principles by which the four modalities operate. The scintillator requirements for these systems are enumerated and the compromises that are made in order to maximize imaging performance utilizing existing scintillating materials are discussed, as is the potential for improving imaging performance by improving scintillator properties.

  19. Polysiloxane scintillator composition

    DOEpatents

    Walker, James K.

    1992-01-01

    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.

  20. Polysiloxane scintillator composition

    DOEpatents

    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.

  1. Boron loaded scintillator

    DOEpatents

    Bell, Zane William [Oak Ridge, TN; Brown, Gilbert Morris [Knoxville, TN; Maya, Leon [Knoxville, TN; Sloop, Jr., Frederick Victor; Sloop, Jr., Frederick Victor [Oak Ridge, TN

    2009-10-20

    A scintillating composition for detecting neutrons and other radiation comprises a phenyl containing silicone rubber with carborane units and at least one phosphor molecule. The carbonate units can either be a carborane molecule dispersed in the rubber with the aid of a compatibilization agent or can be covalently bound to the silicone.

  2. An equatorial scintillation model

    NASA Astrophysics Data System (ADS)

    Fremouw, E. J.; Robins, R. E.

    1985-09-01

    Radiowave scintillation in the presence of natural and/or high altitude nuclear disturbances has the potential to disrupt numerous transionospheric radio and radar systems. This report develops a model characterizing the plasma density irregularities that produce scintillation in the naturally disturbed equatorial F layer. The model has been incorporated into Program WBMOD along with subroutines for computing both link geometry and scintillation indices, the latter by means of phase screen diffraction theory. The model is based on similarly extensive analysis of Wideband data from two equatorial stations. It describes irregularities at an effective height of 350 km that are isotropic across the geomagnetic field and elongated by a factor of 50 along the field and whose one dimensional spatial power spectrum obeys a single regime power law with a (negative) spectral index of 1.5. The height-integrated spectral strength of the irregularities is modeled as a function of solar epoch (sunspot number), the angle between the sunset terminator and the geomagnetic field line through the equatorial F layer point in question (a measure of seasonal and longitudinal variation), time after E-layer sunset on that field line, and the F-layer magnetic apex latitude of the point. The report also highlights a factor missing from complete characterization of the joint seasonal/longitudinal variation of scintillation, thought to depend upon thermospheric neutral winds.

  3. SCINTILLATION EXPOSURE RATE DETECTOR

    DOEpatents

    Spears, W.G.

    1960-11-01

    A radiation detector for gamma and x rays is described. The detector comprises a scintillation crystal disposed between a tantalum shield and the input of a photomultiplier tube, the crystal and the shield cooperating so that their combined response to a given quantity of radiation at various energy levels is substantially constant.

  4. Cherenkov and scintillation light separation on the CheSS experiment

    NASA Astrophysics Data System (ADS)

    Caravaca, Javier; Land, Benjamin; Descamps, Freija; Orebi Gann, Gabriel D.

    2016-09-01

    Separation of the scintillation and Cherenkov light produced in liquid scintillators enables outstanding capabilities for future particle detectors, the most relevant being: particle directionality information in a low energy threshold detector and improved particle identification. The CheSS experiment uses an array of small, fast photomultipliers (PMTs) and state-of-the-art electronics to demonstrate the reconstruction of a Cherenkov ring in liquid scintillator using two techniques: based on the photon density and using the photon hit time information. A charged particle ionizing a scintillation medium produces a prompt Cherenkov cone and late isotropic scintillation light, typically delayed by several ns. The fast response of our PMTs and DAQ provides a precision well below the ns level, making possible the time separation. Furthermore, the usage of the new developed water-based liquid scintillators (WbLS) enhances the separation since it allows tuning of the Cherenkov/Scintillation ratio. Latest results on the separation for pure liquid scintillators and WbLS will be presented.

  5. Reflectance of polytetrafluoroethylene for xenon scintillation light

    SciTech Connect

    Silva, C.; Pinto da Cunha, J.; Pereira, A.; Chepel, V.; Lopes, M. I.; Solovov, V.; Neves, F.

    2010-03-15

    Gaseous and liquid xenon particle detectors are being used in a number of applications including dark matter search and neutrino-less double beta decay experiments. Polytetrafluoroethylene (PTFE) is often used in these detectors both as electrical insulator and as a light reflector to improve the efficiency of detection of scintillation photons. However, xenon emits in the vacuum ultraviolet (VUV) wavelength region ({lambda}{approx_equal}175 nm) where the reflecting properties of PTFE are not sufficiently known. In this work, we report on measurements of PTFE reflectance, including its angular distribution, for the xenon scintillation light. Various samples of PTFE, manufactured by different processes (extruded, expanded, skived, and pressed) have been studied. The data were interpreted with a physical model comprising both specular and diffuse reflections. The reflectance obtained for these samples ranges from about 47% to 66% for VUV light. Other fluoropolymers, namely, ethylene tetrafluoroethylene (ETFE), fluorinated ethylene propylene (FEP), and perfluoro-alkoxyalkane (PFA) were also measured.

  6. Neutron detection with single crystal organic scintillators

    SciTech Connect

    Zaitseva, N; Newby, J; Hamel, S; Carman, L; Faust, M; Lordi, V; Cherepy, N; Stoeffl, W; Payne, S

    2009-07-15

    Detection of high-energy neutrons in the presence of gamma radiation background utilizes pulse-shape discrimination (PSD) phenomena in organics studied previously only with limited number of materials, mostly liquid scintillators and single crystal stilbene. The current paper presents the results obtained with broader varieties of luminescent organic single crystals. The studies involve experimental tools of crystal growth and material characterization in combination with the advanced computer modeling, with the final goal of better understanding the relevance between the nature of the organic materials and their PSD properties. Special consideration is given to the factors that may diminish or even completely obscure the PSD properties in scintillating crystals. Among such factors are molecular and crystallographic structures that determine exchange coupling and exciton mobility in organic materials and the impurity effect discussed on the examples of trans-stilbene, bibenzyl, 9,10-diphenylanthracene and diphenylacetylene.

  7. Plastic scintillators: a powerful tool to reduce mixed waste

    SciTech Connect

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

    2008-07-01

    Wastes containing radioactive and organic compounds (mixed wastes) are difficult to dispose because of the regulations established for nuclear and hazardous wastes. Mixed wastes originate mainly in the emulsions generated in beta emitter determinations by Liquid Scintillation techniques. The use of plastic scintillators instead of liquid cocktails may facilitate the segregation, after measurement, of sample and scintillator without introducing additional wastes in the measurement step. In this study, we compare the capability of Plastic Scintillation (PS) versus Liquid Scintillation (LS) and Cerenkov (C) techniques to determine beta emitters in routine measurements. Results obtained show that high and medium energy beta emitters (Sr-90/Y-90 and C-14) can be quantified in aqueous samples by using PS with similar relative errors (< 5%) as those obtained by LS or C, for any activity level considered. For low energy emitters (H-3), best results using PS are achieved for medium activity levels. Additionally, measurements performed in solutions including alpha (Pu-238) and beta-gamma (Cs-134) emitters confirm the capability of PS to extent the application of this technique to the determination of these types of isotopes. (authors)

  8. Neutron spectroscopy with scintillation detectors using wavelets

    NASA Astrophysics Data System (ADS)

    Hartman, Jessica

    The purpose of this research was to study neutron spectroscopy using the EJ-299-33A plastic scintillator. This scintillator material provided a novel means of detection for fast neutrons, without the disadvantages of traditional liquid scintillation materials. EJ-299-33A provided a more durable option to these materials, making it less likely to be damaged during handling. Unlike liquid scintillators, this plastic scintillator was manufactured from a non-toxic material, making it safer to use, as well as easier to design detectors. The material was also manufactured with inherent pulse shape discrimination abilities, making it suitable for use in neutron detection. The neutron spectral unfolding technique was developed in two stages. Initial detector response function modeling was carried out through the use of the MCNPX Monte Carlo code. The response functions were developed for a monoenergetic neutron flux. Wavelets were then applied to smooth the response function. The spectral unfolding technique was applied through polynomial fitting and optimization techniques in MATLAB. Verification of the unfolding technique was carried out through the use of experimentally determined response functions. These were measured on the neutron source based on the Van de Graff accelerator at the University of Kentucky. This machine provided a range of monoenergetic neutron beams between 0.1 MeV and 24 MeV, making it possible to measure the set of response functions of the EJ-299-33A plastic scintillator detector to neutrons of specific energies. The response of a plutonium-beryllium (PuBe) source was measured using the source available at the University of Nevada, Las Vegas. The neutron spectrum reconstruction was carried out using the experimentally measured response functions. Experimental data was collected in the list mode of the waveform digitizer. Post processing of this data focused on the pulse shape discrimination analysis of the recorded response functions to remove the

  9. Composite scintillator screen

    DOEpatents

    Zeman, Herbert D.

    1994-01-01

    A scintillator screen for an X-ray system includes a substrate of low-Z material and bodies of a high-Z material embedded within the substrate. By preselecting the size of the bodies embedded within the substrate, the spacial separation of the bodies and the thickness of the screen, the sensitivity of the screen to X-rays within a predetermined energy range can be predicted.

  10. An Equatorial Scintillation Model

    DTIC Science & Technology

    1985-09-30

    been incor- porated into Program WBMOD along with subroutines for computing both link geometry and scintillation indices, the latter by means of...phase4screen diffraction theory. , Earlier versions of WBMOD , which are operational at USAF Global Weather Central and at several other user locations...which has been incorporated in WBMOD Version 8DI, is based on similarly extensive analysis of Wideband data from two equatorial stations. It describes

  11. A scintillating fission detector for neutron flux measurements

    SciTech Connect

    Stange, Sy; Esch, Ernst I; Burgett, Eric A; May, Iain; Muenchausen, Ross E; Taw, Felicia; Tovesson, Fredrik K

    2010-01-01

    Neutron flux monitors are commonly used for a variety of nuclear physics applications. A scintillating neutron detector, consisting of a liquid scintillator loaded with fissionable material, has been developed, characterized, and tested in the beam line at the Los Alamos Neutron Science Center, and shows a significant improvement in neutron sensitivity compared with a conventional fission chamber. Recent research on nanocomposite-based scintillators for gamma-ray detection indicates that this approach can be extended to load nanoparticles of fissionable material into a scintillating matrix, with up to three orders of magnitude higher loading than typical fission chambers. This will result in a rugged, cost-efficient detector with high efficiency, a short signal rise time, and the ability to be used in low neutron-flux environments. Initial efforts to utilize the luminescence of uranyl oxide to eliminate the need for wavelength-shifting dyes were unsuccessful. Excitation of uranyl compounds has been reported at wavelengths ranging from 266 nm to 532 nm. However, neither the 300 nm emission of toluene, nor the 350 nm emission of PPO, nor the 410 nm emission of POPOP resulted in significant excitation of and emission by uranyl oxide. As indicated by UV/visible spectroscopy, light emitted at these wavelengths was absorbed by the colored solution. {sup 235}U remains the most attractive candidate for a fissionable scintillator, due to its high fission cross-section and lack of a threshold fission energy, but all solutions containing molecular uranium compounds will be colored, most more highly than the U{sup 6+} compounds used here. Research is therefore continuing toward the fabrication of uranium nanoparticles, in which, due to Rayleigh scattering, the coloration should be less pronounced. The characterization of the thorium-loaded liquid scintillator and the fabrication of the 100 mL detectors for use at LANSCE demonstrated the feasibility of loading fissionable

  12. Experiment to demonstrate separation of Cherenkov and scintillation signals

    DOE PAGES

    Caravaca, J.; Descamps, F. B.; Land, B. J.; ...

    2017-05-05

    The ability to separately identify the Cherenkov and scintillation light components produced in scintillating mediums holds the potential for a major breakthrough in neutrino detection technology, allowing development of a large, low-threshold, directional detector with a broad physics program. Furthermore, the CHESS (CHErenkov/Scintillation Separation) experiment employs an innovative detector design with an array of small, fast photomultiplier tubes and state-of-the-art electronics to demonstrate the reconstruction of a Cherenkov ring in a scintillating medium based on photon hit time and detected photoelectron density. Our paper describes the physical properties and calibration of CHESS along with first results. The ability to reconstructmore » Cherenkov rings are demonstrated in a water target, and a time precision of 338 ± 12 ps FWHM is achieved. Finally, Monte Carlo–based predictions for the ring imaging sensitivity with a liquid scintillator target predict an efficiency for identifying Cherenkov hits of 94 ± 1 % and 81 ± 1 % in pure linear alkyl benzene (LAB) and LAB loaded with 2 g/L of a fluor, PPO, respectively, with a scintillation contamination of 12 ± 1 % and 26 ± 1 % .« less

  13. Experiment to demonstrate separation of Cherenkov and scintillation signals

    NASA Astrophysics Data System (ADS)

    Caravaca, J.; Descamps, F. B.; Land, B. J.; Wallig, J.; Yeh, M.; Orebi Gann, G. D.

    2017-05-01

    The ability to separately identify the Cherenkov and scintillation light components produced in scintillating mediums holds the potential for a major breakthrough in neutrino detection technology, allowing development of a large, low-threshold, directional detector with a broad physics program. The CHESS (CHErenkov/Scintillation Separation) experiment employs an innovative detector design with an array of small, fast photomultiplier tubes and state-of-the-art electronics to demonstrate the reconstruction of a Cherenkov ring in a scintillating medium based on photon hit time and detected photoelectron density. This paper describes the physical properties and calibration of CHESS along with first results. The ability to reconstruct Cherenkov rings is demonstrated in a water target, and a time precision of 338 ±12 ps FWHM is achieved. Monte Carlo-based predictions for the ring imaging sensitivity with a liquid scintillator target predict an efficiency for identifying Cherenkov hits of 94 ±1 % and 81 ±1 % in pure linear alkyl benzene (LAB) and LAB loaded with 2 g/L of a fluor, PPO, respectively, with a scintillation contamination of 12 ±1 % and 26 ±1 % .

  14. New scintillator and waveshifter materials

    NASA Astrophysics Data System (ADS)

    Zheng, H.; Baumbaugh, B.; Gerig, A.; Hurlbut, C.; Kauffman, J.; Marchant, J.; Pla-Dalmau, A.; Reynolds, K.; Ruchti, R.; Warchol, J.; Wayne, M.

    1998-11-01

    Experimental applications requiring fast timing and/or high efficiency position and energy measurements typically use scintillation materials. Scintillators utilized for triggering, tracking, and calorimetry in colliding beam detectors are vulnerable to the high radiation fields associated with such experiments. We have begun an investigation of several fluorescent dyes which might lead to fast, efficient, and radiation resistant scintillators. Preliminary results of spectral analysis and efficiency are presented.

  15. PLASTIC SCINTILLATOR FOR RADIATION DOSIMETRY.

    PubMed

    Kim, Yewon; Yoo, Hyunjun; Kim, Chankyu; Lim, Kyung Taek; Moon, Myungkook; Kim, Jongyul; Cho, Gyuseong

    2016-09-01

    Inorganic scintillators, composed of high-atomic-number materials such as the CsI(Tl) scintillator, are commonly used in commercially available a silicon diode and a scintillator embedded indirect-type electronic personal dosimeters because the light yield of the inorganic scintillator is higher than that of an organic scintillator. However, when it comes to tissue-equivalent dose measurements, a plastic scintillator such as polyvinyl toluene (PVT) is a more appropriate material than an inorganic scintillator because of the mass energy absorption coefficient. To verify the difference in the absorbed doses for each scintillator, absorbed doses from the energy spectrum and the calculated absorbed dose were compared. From the results, the absorbed dose of the plastic scintillator was almost the same as that of the tissue for the overall photon energy. However, in the case of CsI, it was similar to that of the tissue only for a photon energy from 500 to 4000 keV. Thus, the values and tendency of the mass energy absorption coefficient of the PVT are much more similar to those of human tissue than those of the CsI. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. A new tritiated water measurement method with plastic scintillator pellets.

    PubMed

    Furuta, Etsuko; Iwasaki, Noriko; Kato, Yuka; Tomozoe, Yusuke

    2016-01-01

    A new tritiated water measurement method with plastic scintillator pellets (PS-pellets) by using a conventional liquid scintillation counter was developed. The PS-pellets used were 3 mm in both diameter and length. A low potassium glass vial was filled full with the pellets, and tritiated water was applied to the vial from 5 to 100 μl. Then, the sample solution was scattered in the interstices of the pellets in a vial. This method needs no liquid scintillator, so no liquid organic waste fluid is generated. The counting efficiency with the pellets was approximately 48 % when a 5 μl solution was used, which was higher than that of conventional measurement using liquid scintillator. The relationship between count rate and activity showed good linearity. The pellets were able to be used repeatedly, so few solid wastes are generated with this method. The PS-pellets are useful for tritiated water measurement; however, it is necessary to develop a new device which can be applied to a larger volume and measure low level concentration like an environmental application.

  17. A scintillator purification system for the Borexino solar neutrino detector

    NASA Astrophysics Data System (ADS)

    Benziger, J.; Cadonati, L.; Calaprice, F.; Chen, M.; Corsi, A.; Dalnoki-Veress, F.; Fernholz, R.; Ford, R.; Galbiati, C.; Goretti, A.; Harding, E.; Ianni, Aldo; Ianni, Andrea; Kidner, S.; Leung, M.; Loeser, F.; McCarty, K.; McKinsey, D.; Nelson, A.; Pocar, A.; Salvo, C.; Schimizzi, D.; Shutt, T.; Sonnenschein, A.

    2008-03-01

    Purification of the 278 tons of liquid scintillator and 889 tons of buffer shielding for the Borexino solar neutrino detector is performed with a system that combines distillation, water extraction, gas stripping, and filtration. This paper describes the principles of operation, design, and construction of that purification system, and reviews the requirements and methods to achieve system cleanliness and leak-tightness.

  18. DESCANT - the deuterated scintillator array for neutron tagging

    NASA Astrophysics Data System (ADS)

    Garrett, P. E.

    2014-01-01

    The DESCANT array is a new device for neutron detection based on deuterated liquid scintillator. It has been designed to be coupled with the TIGRESS and GRIFFIN γ-ray spectrometers to enable neutron tagging in fusion-evaporation reactions, and β-delayed neutron studies.

  19. Detecting dark matter with scintillating bubble chambers

    NASA Astrophysics Data System (ADS)

    Zhang, Jianjie; Dahl, C. Eric; Jin, Miaotianzi; Baxter, Daniel

    2016-03-01

    Threshold based direct WIMP dark matter detectors such as the superheated bubble chambers developed by the PICO experiment have demonstrated excellent electron-recoil and alpha discrimination, excellent scalability, ease of change of target fluid, and low cost. However, the nuclear-recoil like backgrounds have been a limiting factor in their dark matter sensitivity. We present a new type of detector, the scintillating bubble chamber, which reads out the scintillation pulse of the scattering events as well as the pressure, temperature, acoustic traces, and bubble images as a conventional bubble chamber does. The event energy provides additional handle to discriminate against the nuclear-recoil like backgrounds. Liquid xenon is chosen as the target fluid in our prototyping detector for its high scintillation yield and suitable vapor pressure which simplifies detector complexity. The detector can be used as an R&D tool to study the backgrounds present in the current PICO bubble chambers or as a prototype for standalone dark matter detectors in the future. Supported by DOE Grant DE-SC0012161.

  20. GPS Scintillation Analysis.

    DTIC Science & Technology

    2007-11-02

    Rev. 2-89) Prescribed by ANSI Std. Z39-1 298-102 TABLE OF CONTENTS 1. INTRODUCTION 1 2. GPS COMPARISON WITH ALL-SKY IMAGES OVER AGUA VERDE...Depletions from 1 October 1994 2 3. GPS data from Agua Verde, Chile on the night of 1 October 1994 3 4. PL-SCINDA display of GPS ionospheric...comparison of GPS measurements with GOES8 L-band scintillation data, are discussed. 2. GPS COMPARISON WITH ALL-SKY IMAGES OVER AGUA VERDE, CHILE As

  1. Scintillation detector for carbon-14

    NASA Technical Reports Server (NTRS)

    Knoll, G. F.; Rogers, W. L.

    1971-01-01

    Detector consists of plastic, cylindrical double-wall scintillation cell, which is filled with gas to be analyzed. Thin, inner cell wall is isolated optically from outer (guard) scintillator wall by evaporated-aluminum coating. Bonding technique provides mechanical support to cell wall when device is exposed to high temperatures.

  2. Hybrid scintillators for neutron discrimination

    DOEpatents

    Feng, Patrick L; Cordaro, Joseph G; Anstey, Mitchell R; Morales, Alfredo M

    2015-05-12

    A composition capable of producing a unique scintillation response to neutrons and gamma rays, comprising (i) at least one surfactant; (ii) a polar hydrogen-bonding solvent; and (iii) at least one luminophore. A method including combining at least one surfactant, a polar hydrogen-bonding solvent and at least one luminophore in a scintillation cell under vacuum or an inert atmosphere.

  3. Development of intrinsic IPT scintillator

    SciTech Connect

    Bross, A.D.

    1989-07-31

    We report on the development of a new polystyrene based plastic scintillator. Optical absorption, fluorescence and light output measurements are presented. Preliminary results of radiation damage effects are also given and compared to the effects on a commercial plastic scintillator, NE 110. 6 refs., 12 figs.

  4. Development of radiation hard scintillators

    NASA Astrophysics Data System (ADS)

    Markley, F.; Davidson, M.; Keller, J.; Foster, G.; Pla-Dalmau, A.; Harmon, J.; Biagtan, E.; Schueneman, G.; Senchishin, V.; Gustfason, H.

    1993-11-01

    The authors have demonstrated that the radiation stability of scintillators made from styrene polymer is very much improved by compounding with pentaphenyl trimethyl trisiloxane (DC 705 vacuum pump oil). The resulting scintillators are softer than desired, so they decided to make the scintillators directly from monomer where the base resin could be easily crosslinked to improve the mechanical properties. They can now demonstrate that scintillators made directly from the monomer, using both styrene and 4-methyl styrene, are also much more radiation resistant when modified with DC705 oil. In fact, they retain from 92% to 95% of their original light output after gamma irradiation to 10 Mrads in nitrogen with air annealing. When these scintillators made directly from monomer are compared with scintillators of the same composition made from polymer the latter have much higher light outputs. They commonly reach 83% while those made from monomer give only 50% to 60% relative to the reference, BC408. When oil modified scintillators using both p-terphenyl and tetra phenyl butadiene are compared with identical scintillators except that they use 3 hydroxy-flavone as the only luminophore the radiation stability is the same. However the 3HF system gives only 30% as much light as BC408 instead of 83% when both are measured with a green extended Phillips XP2081B phototube.

  5. Extruding plastic scintillator at Fermilab

    SciTech Connect

    Anna Pla-Dalmau; Alan D. Bross; Victor V. Rykalin

    2003-10-31

    An understanding of the costs involved in the production of plastic scintillators and the development of a less expensive material have become necessary with the prospects of building very large plastic scintillation detectors. Several factors contribute to the high cost of plastic scintillating sheets, but the principal reason is the labor-intensive nature of the manufacturing process. In order to significantly lower the costs, the current casting procedures had to be abandoned. Since polystyrene is widely used in the consumer industry, the logical path was to investigate the extrusion of commercial-grade polystyrene pellets with dopants to yield high quality plastic scintillator. This concept was tested and high quality extruded plastic scintillator was produced. The D0 and MINOS experiments are already using extruded scintillator strips in their detectors. An extrusion line has recently been installed at Fermilab in collaboration with NICADD (Northern Illinois Center for Accelerator and Detector Development). This new facility will serve to further develop and improve extruded plastic scintillator. This paper will discuss the characteristics of extruded plastic scintillator and its raw materials, the different manufacturing techniques and the current R&D program at Fermilab.

  6. Development of radiation hard scintillators

    SciTech Connect

    Markley, F.; Davidson, M.; Keller, J.; Foster, G.; Pla-Dalmau, A.; Harmon, J.; Biagtan, E.; Schueneman, G.; Senchishin, V.; Gustfason, H.; Rivard, M.

    1993-11-01

    The authors have demonstrated that the radiation stability of scintillators made from styrene polymer is very much improved by compounding with pentaphenyltrimethyltrisiloxane (DC 705 vacuum pump oil). The resulting scintillators are softer than desired, so they decided to make the scintillators directly from monomer where the base resin could be easily crosslinked to improve the mechanical properties. They can now demonstrate that scintillators made directly from the monomer, using both styrene and 4-methyl styrene, are also much more radiation resistant when modified with DC705 oil. In fact, they retain from 92% to 95% of their original light output after gamma irradiation to 10 Mrads in nitrogen with air annealing. When these scintillators made directly from monomer are compared with scintillators of the same composition made from polymer the latter have much higher light outputs. They commonly reach 83% while those made form monomer give only 50% to 60% relative to the reference, BC408. When oil modified scintillators using both p-terphenyl and tetraphenylbutadiene are compared with identical scintillators except that they use 3 hydroxy-flavone as the only luminophore the radiation stability is the same. However the 3HF system gives only 30% as much light as BC408 instead of 83% when both are measured with a green extended Phillips XP2081B phototube.

  7. Scintillator based beta batteries

    NASA Astrophysics Data System (ADS)

    Rensing, Noa M.; Tiernan, Timothy C.; Shirwadkar, Urmila; O'Dougherty, Patrick; Freed, Sara; Hawrami, Rastgo; Squillante, Michael R.

    2013-05-01

    Some long-term, remote applications do not have access to conventional harvestable energy in the form of solar radiation (or other ambient light), wind, environmental vibration, or wave motion. Radiation Monitoring Devices, Inc. (RMD) is carrying out research to address the most challenging applications that need power for many months or years and which have undependable or no access to environmental energy. Radioisotopes are an attractive candidate for this energy source, as they can offer a very high energy density combined with a long lifetime. Both large scale nuclear power plants and radiothermal generators are based on converting nuclear energy to heat, but do not scale well to small sizes. Furthermore, thermo-mechanical power plants depend on moving parts, and RTG's suffer from low efficiency. To address the need for compact nuclear power devices, RMD is developing a novel beta battery, in which the beta emissions from a radioisotope are converted to visible light in a scintillator and then the visible light is converted to electrical power in a photodiode. By incorporating 90Sr into the scintillator SrI2 and coupling the material to a wavelength-matched solar cell, we will create a scalable, compact power source capable of supplying milliwatts to several watts of power over a period of up to 30 years. We will present the latest results of radiation damage studies and materials processing development efforts, and discuss how these factors interact to set the operating life and energy density of the device.

  8. Antineutrino geophysics with liquid scintillator detectors

    NASA Astrophysics Data System (ADS)

    Rothschild, Casey G.; Chen, Mark C.; Calaprice, Frank P.

    Detecting the antineutrinos emitted by the decay of radioactive elements in the mantle and crust could provide a direct measurement of the total abundance of uranium and thorium in the Earth. In calculating the antineutrino flux at specific sites, the local geology of the crust and the background from the world's nuclear power reactors are important considerations. Employing a global crustal map, with type and thickness data, and using recent estimates of the uranium and thorium distribution in the Earth, we calculate the antineutrino event rate for two new neutrino detectors. We show that spectral features allow terrestrial antineutrino events to be identified above reactor antineutrino backgrounds and that the uranium and thorium contributions can be separately determined.

  9. Large-Area Liquid Scintillation Detector Slab

    NASA Astrophysics Data System (ADS)

    Crouch, M. F.; Gurr, H. S.; Hruschka, A. A.; Jenkins, T. L.; Kropp, W. P.; Reines, P.; Sobel, H.

    The following sections are included: * SUMMARY * INTRODUCTION * DETECTOR RESPONSE FUNCTION F(z) AND EVENT POSITION DETERMINATION * REFINEMENTS IN THE DETECTOR CONFIGURATION DESIGN * DETECTOR PERFORMANCE * APPENDIX * REFERENCES

  10. Proton recoil scintillator neutron rem meter

    DOEpatents

    Olsher, Richard H.; Seagraves, David T.

    2003-01-01

    A neutron rem meter utilizing proton recoil and thermal neutron scintillators to provide neutron detection and dose measurement. In using both fast scintillators and a thermal neutron scintillator the meter provides a wide range of sensitivity, uniform directional response, and uniform dose response. The scintillators output light to a photomultiplier tube that produces an electrical signal to an external neutron counter.

  11. Gadolinium-loaded gel scintillators for neutron and antineutrino detection

    SciTech Connect

    Riddle, Catherine Lynn; Akers, Douglas William; Demmer, Ricky Lynn; Paviet, Patricia Denise; Drigert, Mark William

    2016-11-29

    A gadolinium (Gd) loaded scintillation gel (Gd-ScintGel) compound allows for neutron and gamma-ray detection. The unique gel scintillator encompasses some of the best features of both liquid and solid scintillators, yet without many of the disadvantages associated therewith. Preferably, the gel scintillator is a water soluble Gd-DTPA compound and water soluble fluorophores such as: CdSe/ZnS (or ZnS) quantum dot (Q-dot) nanoparticles, coumarin derivatives 7-hydroxy-4-methylcoumarin, 7-hydroxy-4-methylcoumarin-3-acetic acid, 7-hydroxycoumarin-3-carboxylic acid, and Alexa Fluor 350 as well as a carbostyril compound, carbostyril 124 in a stable water-based gel, such as methylcellulose or polyacrylamide polymers. The Gd-loaded ScintGel allows for a homogenious distribution of the Gd-DTPA and the fluorophores, and yields clean fluorescent emission peaks. A moderator, such as deuterium or a water-based clear polymer, can be incorporated in the Gd-ScintGel. The gel scintillators can be used in compact detectors, including neutron and antineutrino detectors.

  12. High energy resolution plastic scintillator

    NASA Astrophysics Data System (ADS)

    van Loef, Edgar V.; Feng, Patrick; Markosyan, Gary; Shirwadkar, Urmila; Doty, Patrick; Shah, Kanai S.

    2016-09-01

    In this paper we present results on a novel tin-loaded plastic scintillator. We will show that this particular plastic scintillator has a light output similar to that of BGO, a fast scintillation decay (< 10 ns), exhibits good neutron/gamma PSD with a Figure-of-Merit of 1.3 at 2.5 MeVee cut-off energy, and excellent energy resolution of about 12% (FWHM) at 662 keV. Under X-ray excitation, the radioluminescence spectrum exhibits a broad band between 350 and 500 nm peaking at 420 nm which is well-matched to bialkali photomultiplier tubes and UV-enhanced photodiodes.

  13. Scintillator materials containing lanthanum fluorides

    DOEpatents

    Moses, William W.

    1991-01-01

    An improved radiation detector containing a crystalline mixture of LaF.sub.3 and CeF.sub.3 as the scintillator element is disclosed. Scintillators made with from 25% to 99.5% LaF.sub.3 and the remainder CeF.sub.3 have been found to provide a balance of good stopping power, high light yield and short decay constant that is equal to or superior to other known scintillator materials, and which may be processed from natural starting materials containing both rare earth elements. The radiation detectors disclosed are favorably suited for use in general purpose detection and in positron emission tomography.

  14. Ionospheric scintillation studies

    NASA Technical Reports Server (NTRS)

    Rino, C. L.; Freemouw, E. J.

    1973-01-01

    The diffracted field of a monochromatic plane wave was characterized by two complex correlation functions. For a Gaussian complex field, these quantities suffice to completely define the statistics of the field. Thus, one can in principle calculate the statistics of any measurable quantity in terms of the model parameters. The best data fits were achieved for intensity statistics derived under the Gaussian statistics hypothesis. The signal structure that achieved the best fit was nearly invariant with scintillation level and irregularity source (ionosphere or solar wind). It was characterized by the fact that more than 80% of the scattered signal power is in phase quadrature with the undeviated or coherent signal component. Thus, the Gaussian-statistics hypothesis is both convenient and accurate for channel modeling work.

  15. Drift scintillation meter

    NASA Astrophysics Data System (ADS)

    1984-03-01

    This is the final report for the subject contract under which The University of Texas at Dallas (UTD) built, tested and delivered an engineering model and three flight versions of the Drift Scintillation Meter (DSM) to the Air Force Geophysics Laboratory for flight on the Air Force DMSP satellites. The report is divided into three sections. Section 1 contains the instrument description and theory of operation. Section 2 contains a description of planned spacecraft-level instrument testing, stimulation requirements and instrument handling and safety. Section 3 contains an instrument interconnection diagram and a list of the schematics, drawings, parts lists and wiring lists that describe the as-built configuration of the instrument. This documentation is available in the R&D Equipment Information Reports that were submitted to AFGL after each instrument delivery.

  16. Scintillator fiber optic long counter

    DOEpatents

    McCollum, Tom; Spector, Garry B.

    1994-01-01

    A flat response position sensitive neutron detector capable of providing neutron spectroscopic data utilizing scintillator fiber optic filaments embedded in a neutron moderating housing having an open end through which neutrons enter to be detected.

  17. Scintillator fiber optic long counter

    DOEpatents

    McCollum, T.; Spector, G.B.

    1994-03-29

    A flat response position sensitive neutron detector capable of providing neutron spectroscopic data utilizing scintillator fiber optic filaments embedded in a neutron moderating housing having an open end through which neutrons enter to be detected is described. 11 figures.

  18. Photon statistics in scintillation crystals

    NASA Astrophysics Data System (ADS)

    Bora, Vaibhav Joga Singh

    Scintillation based gamma-ray detectors are widely used in medical imaging, high-energy physics, astronomy and national security. Scintillation gamma-ray detectors are eld-tested, relatively inexpensive, and have good detection eciency. Semi-conductor detectors are gaining popularity because of their superior capability to resolve gamma-ray energies. However, they are relatively hard to manufacture and therefore, at this time, not available in as large formats and much more expensive than scintillation gamma-ray detectors. Scintillation gamma-ray detectors consist of: a scintillator, a material that emits optical (scintillation) photons when it interacts with ionization radiation, and an optical detector that detects the emitted scintillation photons and converts them into an electrical signal. Compared to semiconductor gamma-ray detectors, scintillation gamma-ray detectors have relatively poor capability to resolve gamma-ray energies. This is in large part attributed to the "statistical limit" on the number of scintillation photons. The origin of this statistical limit is the assumption that scintillation photons are either Poisson distributed or super-Poisson distributed. This statistical limit is often dened by the Fano factor. The Fano factor of an integer-valued random process is dened as the ratio of its variance to its mean. Therefore, a Poisson process has a Fano factor of one. The classical theory of light limits the Fano factor of the number of photons to a value greater than or equal to one (Poisson case). However, the quantum theory of light allows for Fano factors to be less than one. We used two methods to look at the correlations between two detectors looking at same scintillation pulse to estimate the Fano factor of the scintillation photons. The relationship between the Fano factor and the correlation between the integral of the two signals detected was analytically derived, and the Fano factor was estimated using the measurements for SrI2:Eu, YAP

  19. About NICADD extruded scintillating strips

    SciTech Connect

    Dyshkant, A.; Beznosko, D.; Blazey, G.; Chakraborty, D.; Francis, K.; Kubik, D.; Lima, J.G.; Rykalin, V.; Zutshi, v.; Baldina, E.; Bross, A.; Deering, P.; Nebel, T.; Pla-Dalmau, A.; Schellpfeffer, J.; Serritella, C.; Zimmerman, J.; /Fermilab

    2005-04-01

    The results of control measurements of extruded scintillating strip responses to a radioactive source Sr-90 are provided, and details of strip choice, preparation, and method of measurement are included. About four hundred one meter long extruded scintillating strips were measured at four different points. These results were essential for prototyping a tail catcher and muon tracker for a future international electron positron linear collider detector.

  20. Cherenkov and scintillation light separation on the TheiaR &D experiment

    NASA Astrophysics Data System (ADS)

    Caravaca, Javier; Land, Benjamin

    2016-03-01

    Identifying by separate the scintillation and Cherenkov light produced in a scintillation medium enables outstanding capabilities for future particle detectors, being the most relevant: allowing particle directionality information in a low energy threshold detector and improved particle identification. The TheiaR &D experiment uses an array of small and fast photomultipliers (PMTs) and state-of-the-art electronics to demonstrate the reconstruction of a Cherenkov ring in a scintillation medium, based on the number of produced photoelectrons and the timing information. A charged particle ionizing a scintillation medium produces a prompt Cherenkov cone and late isotropic scintillation light, typically delayed by <1ns. The fast response of our PMTs and DAQ provides a precision well below the ns level, making possible the time separation. Furthermore, the usage of the new developed water-based liquid scintillators (WBLS) provides a medium with a tunable Cherenkov/Scintillation light yield ratio, enhancing the visibility of the dimer Cherenkov light in presence of the scintillation light. Description of the experiment, details of the analysis and preliminary results of the first months of running will be discussed.

  1. Extruded plastic scintillator including inorganic powders

    DOEpatents

    Bross, Alan D.; Mellott, Kerry L.; Pla-Dalmau, Anna

    2006-06-27

    A method for producing a plastic scintillator is disclosed. A plurality of nano-sized particles and one or more dopants can be combined with a plastic material for the formation of a plastic scintillator thereof. The nano-sized particles, the dopant and the plastic material can be combined within the dry inert atmosphere of an extruder to produce a reaction that results in the formation of a plastic scintillator thereof and the deposition of energy within the plastic scintillator, such that the plastic scintillator produces light signifying the detection of a radiative element. The nano-sized particles can be treated with an inert gas prior to processing the nano-sized particles, the dopant and the plastic material utilizing the extruder. The plastic scintillator can be a neutron-sensitive scintillator, x-ray sensitive scintillator and/or a scintillator for the detection of minimum ionizing particles.

  2. Scintillation Light Background Discrimination in the SBND Experiment

    NASA Astrophysics Data System (ADS)

    Hill, Colton; Szelc, Andrzej; Garcia-Gamez, Diego

    2017-01-01

    SBND is a liquid argon detector being constructed along the Fermilab Booster Neutrino Beamline. As a part of the Short Baseline Neutrino Program, it will attempt to resolve the MiniBooNE low energy excess hinting at possible oscillations into sterile neutrinos. SBND will install a light detection system with a much higher expected light yield than previous argon neutrino experiments. This will enable scintillation light to play a key role in measuring the properties of neutrinos, and improve the sensitivity to interesting low energy physics such as supernova neutrinos or nucleon decay. A challenge for low energy measurements in large liquid argon detectors is the contribution from 39Ar, which being present in atmospheric argon, provides a steady source of scintillation light. I will present studies to develop methods of reducing the impact of 39Ar backgrounds while maintaining sensitivity to low energy physics signals.

  3. Characterization of cerium fluoride nanocomposite scintillators

    SciTech Connect

    Stange, Sy; Esch, Ernst I; Brown, Leif O; Couture, Aaron J; Mckigney, Edward A; Muenchausen, Ross E; Del Sesto, Rico E; Gilbertson, Robert D; Mccleskey, T Mark; Reifarth, Rene

    2009-01-01

    Measurement of the neutron capture cross-sections of a number of short-lived isotopes would advance both pure and applied scientific research. These cross-sections are needed for calculation of criticality and waste production estimates for the Advanced Fuel Cycle Initiative, for analysis of data from nuclear weapons tests, and to improve understanding of nucleosynthesis. However, measurement of these cross-sections would require a detector with a faster signal decay time than those used in existing neutron capture experiments. Crystals of faster detector materials are not available in sufficient sizes and quantities to supply these large-scale experiments. Instead, we propose to use nanocomposite detectors, consisting of nanoscale particles of a scintillating material dispersed in a matrix material. We have successfully fabricated cerium fluoride (CeF{sub 3}) nanoparticles and dispersed them in a liquid matrix. We have characterized this scintillator and have measured its response to neutron capture. Results of the optical, structural, and radiation characterization will be presented.

  4. Characterization of Deuterated-xylene Scintillator as a Neutron Spectrometer

    DOE PAGES

    Di Fulvio, Angela; Becchetti, F. D.; Raymond, R. S.; ...

    2016-11-16

    We have experimentally characterized the neutron light output response functions of a deuterated-xylene scintillator for neutron energies lower than 10 MeV. We then used the response matrix to unfold the energy distribution of neutrons produced via several reactions, i.e. spontaneous fission, d(d,n)3He, 27Al(d,n)28Si, and 9Be(alpha,n)12C. Organic scintillators based on deuterated compounds show a fast response and good gamma-neutron discrimination capability, similar to proton-based scintillators. Deuterated scintillators can also effectively provide neutron spectra by unfolding measured data with the detector response matrix, without the need of time-of-flight. Deuteron recoils, produced by elastic collisions between deuterium and impinging neutrons, are preferentially forward-scattered.more » This non-isotropic reaction results in distinct peaks in the response functions to monoenergetic neutrons. In this work, we evaluated a custom-fabricated 7.62 cm x 7.62 cm deuterated-xylene (EJ301D) liquid scintillator. This liquid has a low volatility and higher flash point, compared to benzene-based deuterated detectors, e.g. EJ315 and NE230. We measured the EJ301D detector neutron response matrix (up to 6 MeV neutron energy) using an intense Cf252 source and the time-of-flight technique. The number of response functions obtained using our method is only limited by counting statistics and by the experimentally achievable energy resolution. Multi-channel unfolding was performed successfully for neutron spectra with different energy spectra.« less

  5. Characterization of Deuterated-xylene Scintillator as a Neutron Spectrometer

    SciTech Connect

    Di Fulvio, Angela; Becchetti, F. D.; Raymond, R. S.; Torres-Isea, R. O.; Clarke, S. D.; Pozzi, Sara A.

    2016-11-16

    We have experimentally characterized the neutron light output response functions of a deuterated-xylene scintillator for neutron energies lower than 10 MeV. We then used the response matrix to unfold the energy distribution of neutrons produced via several reactions, i.e. spontaneous fission, d(d,n)3He, 27Al(d,n)28Si, and 9Be(alpha,n)12C. Organic scintillators based on deuterated compounds show a fast response and good gamma-neutron discrimination capability, similar to proton-based scintillators. Deuterated scintillators can also effectively provide neutron spectra by unfolding measured data with the detector response matrix, without the need of time-of-flight. Deuteron recoils, produced by elastic collisions between deuterium and impinging neutrons, are preferentially forward-scattered. This non-isotropic reaction results in distinct peaks in the response functions to monoenergetic neutrons. In this work, we evaluated a custom-fabricated 7.62 cm x 7.62 cm deuterated-xylene (EJ301D) liquid scintillator. This liquid has a low volatility and higher flash point, compared to benzene-based deuterated detectors, e.g. EJ315 and NE230. We measured the EJ301D detector neutron response matrix (up to 6 MeV neutron energy) using an intense Cf252 source and the time-of-flight technique. The number of response functions obtained using our method is only limited by counting statistics and by the experimentally achievable energy resolution. Multi-channel unfolding was performed successfully for neutron spectra with different energy spectra.

  6. Molecular origins of scintillation in organic scintillators (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Feng, Patrick; Mengesha, Wondwosen; Myllenbeck, Nicholas

    2016-09-01

    Organic-based scintillators are indispensable materials for radiation detection owing to their high sensitivity to fast neutrons, low cost, and tailorable properties. There has been a recent resurgence of interest in organic scintillators due to exciting discoveries related to neutron discrimination and gamma-ray spectroscopy, which represent capabilities previously thought not possible in these materials. I will discuss our development of crystalline and polymer-based scintillators for these applications. Structure-property relationships related to intermolecular interactions and host-guest electronic exchange will be discussed in the context of energy-transfer pathways relevant to scintillation. An emphasis will be placed on the rational design of these materials, as guided by first principles and DFT calculations. Two related topics will be discussed: 1) Incorporation of organometallic triplet-harvesting additives to plastic scintillator matrices to confer a 'two-state' (singlet and triplet) luminescence signature to different types of ionizing radiation. This approach relies upon energetic and spatial overlap between the donor and acceptor excited states for efficient electronic exchange. Key considerations also include synthetic modification of the luminescence spectra and kinetics, as well as the addition of secondary additives to increase the recombination efficiency. 2) Design of organotin-containing plastic scintillators as a route towards gamma-ray spectroscopy. Organometallic compounds were selected on the basis of distance-dependent quenching relationships, phase compatibility with the polymer matrix, and the gamma-ray cross sections. This approach is guided by molecular modeling and radiation transport modeling to achieve the highest possible detection sensitivity luminescence intensity.

  7. FNAL-NICADD extruded scintillator

    SciTech Connect

    Beznosko, D.; Bross, A.; Dyshkant, A.; Pla-Dalmau, A.; Rykalin, V.; /Northern Illinois U.

    2005-09-01

    The possibility to produce a scintillator that satisfies the demands of physicists from different science areas has emerged with the installation of an extrusion line at Fermi National Accelerator Laboratory (FNAL). The extruder is the product of the fruitful collaboration between FNAL and Northern Illinois Center for Accelerator and Detector Development (NICADD) at Northern Illinois University (NIU). The results from the light output, light attenuation length and mechanical tolerance indicate that FNAL-NICADD scintillator is of high quality. Improvements in the extrusion die will yield better scintillator profiles and decrease the time needed for initial tuning. This paper will present the characteristics of the FNAL-NICADD scintillator based on the measurements performed. They include the response to MIPs from cosmic rays for individual extruded strips and irradiation studies where extruded samples were irradiated up to 1 Mrad. We will also discuss the results achieved with a new die design. The attractive perspective of using the extruded scintillator with MRS (Metal Resistive Semiconductor) photodetector readout will also be shown.

  8. Advances in scintillators for medical imaging applications

    NASA Astrophysics Data System (ADS)

    van Loef, Edgar V.; Shah, Kanai S.

    2014-09-01

    A review is presented of some recent work in the field of inorganic scintillator research for medical imaging applications, in particular scintillation detectors for Single-Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET).

  9. Scintillating glass fiber neutron senors

    SciTech Connect

    Abel, K.H.; Arthur, R.J.; Bliss, M.

    1994-04-01

    Cerium-doped lithium-silicate glass fibers have been developed at Pacific Northwest Laboratory (PNL) for use as thermal neutron detectors. By using highly-enriched {sup 6} Li , these fibers efficiently capture thermal neutrons and produce scintillation light that can be detected at the ends of the fibers. Advantages of scintillating fibers over {sup 3}He or BF{sub 3} proportional tubes include flexibility in geometric configuration, ruggedness in high-vibration environments, and less detector weight for the same neutron sensitivity. This paper describes the performance of these scintillating fibers with regard to count rates, pulse height spectra, absolute efficiencies, and neutron/gamma discrimination. Fibers with light transmission lengths (1/e) of greater than 2 m have been produced at PNL. Neutron sensors in fiber form allow development of a variety of neutron detectors packaged in previously unavailable configurations. Brief descriptions of some of the devices already produced are included to illustrate these possibilities.

  10. Unitary scintillation detector and system

    DOEpatents

    McElhaney, Stephanie A.; Chiles, Marion M.

    1994-01-01

    The invention is a unitary alpha, beta, and gamma scintillation detector and system for sensing the presence of alpha, beta, and gamma radiations selectively or simultaneously. The scintillators are mounted in a light-tight housing provided with an entrance window for admitting alpha, beta, and gamma radiation and excluding ambient light from the housing. Light pulses from each scintillator have different decay constants that are converted by a photosensitive device into corresponding differently shaped electrical pulses. A pulse discrimination system identifies the electrical pulses by their respective pulse shapes which are determined by decay time. The identified electrical pulses are counted in separate channel analyzers to indicate the respective levels of sensed alpha, beta, and gamma radiations.

  11. Unitary scintillation detector and system

    DOEpatents

    McElhaney, S.A.; Chiles, M.M.

    1994-05-31

    The invention is a unitary alpha, beta, and gamma scintillation detector and system for sensing the presence of alpha, beta, and gamma radiations selectively or simultaneously. The scintillators are mounted in a light-tight housing provided with an entrance window for admitting alpha, beta, and gamma radiation and excluding ambient light from the housing. Light pulses from each scintillator have different decay constants that are converted by a photosensitive device into corresponding differently shaped electrical pulses. A pulse discrimination system identifies the electrical pulses by their respective pulse shapes which are determined by decay time. The identified electrical pulses are counted in separate channel analyzers to indicate the respective levels of sensed alpha, beta, and gamma radiations. 10 figs.

  12. Fracture-resistant lanthanide scintillators

    DOEpatents

    Doty, F Patrick [Livermore, CA

    2011-01-04

    Lanthanide halide alloys have recently enabled scintillating gamma ray spectrometers comparable to room temperature semiconductors (<3% FWHM energy resolutions at 662 keV). However brittle fracture of these materials upon cooling hinders the growth of large volume crystals. Efforts to improve the strength through non-lanthanide alloy substitution, while preserving scintillation, have been demonstrated. Isovalent alloys having nominal compositions of comprising Al, Ga, Sc, Y, and In dopants as well as aliovalent alloys comprising Ca, Sr, Zr, Hf, Zn, and Pb dopants were prepared. All of these alloys exhibit bright fluorescence under UV excitation, with varying shifts in the spectral peaks and intensities relative to pure CeBr.sub.3. Further, these alloys scintillate when coupled to a photomultiplier tube (PMT) and exposed to .sup.137Cs gamma rays.

  13. Development of radiation hard scintillators

    NASA Astrophysics Data System (ADS)

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

    1993-01-01

    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.

  14. Scintillation-Hardened GPS Receiver

    NASA Technical Reports Server (NTRS)

    Stephens, Donald R.

    2015-01-01

    CommLargo, Inc., has developed a scintillation-hardened Global Positioning System (GPS) receiver that improves reliability for low-orbit missions and complies with NASA's Space Telecommunications Radio System (STRS) architecture standards. A software-defined radio (SDR) implementation allows a single hardware element to function as either a conventional radio or as a GPS receiver, providing backup and redundancy for platforms such as the International Space Station (ISS) and high-value remote sensing platforms. The innovation's flexible SDR implementation reduces cost, weight, and power requirements. Scintillation hardening improves mission reliability and variability. In Phase I, CommLargo refactored an open-source GPS software package with Kalman filter-based tracking loops to improve performance during scintillation and also demonstrated improved navigation during a geomagnetic storm. In Phase II, the company generated a new field-programmable gate array (FPGA)-based GPS waveform to demonstrate on NASA's Space Communication and Navigation (SCaN) test bed.

  15. Interstellar scintillations of pulsar radiation.

    PubMed

    Lang, K R

    1969-12-12

    Time fluctuations in the intensity of pulsed radiation from CP 0834, CP 1133, AP 1237, and CP 1919 have been investigated. Power spectra, modulation indices, frequency distributions, and decorrelation frequencies are consistent with scintillation theory. If it is assumed that these scintillations are due to irregularities in the interstellar medium that travel at a velocity of 20 kilometers per second, the irregularities have a scale size on the order of 10(4) kilometers and a distance from the earth of approximately 70 parsecs. These interstellar scintillations would not have been observed if the apparent angular diameters of the pulsars were larger than 0.3 X 10(-5) second of arc, and they would cause even a point radio source to have an apparent angular diameter of approximately 10(-3) second of arc at 318 megahertz.

  16. Development of radiation hard scintillators

    SciTech Connect

    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.

  17. Optical artefact characterization and correction in volumetric scintillation dosimetry

    PubMed Central

    Robertson, Daniel; Hui, Cheukkai; Archambault, Louis; Mohan, Radhe; Beddar, Sam

    2014-01-01

    The goals of this study were (1) to characterize the optical artefacts affecting measurement accuracy in a volumetric liquid scintillation detector, and (2) to develop methods to correct for these artefacts. The optical artefacts addressed were photon scattering, refraction, camera perspective, vignetting, lens distortion, the lens point spread function, stray radiation, and noise in the camera. These artefacts were evaluated by theoretical and experimental means, and specific correction strategies were developed for each artefact. The effectiveness of the correction methods was evaluated by comparing raw and corrected images of the scintillation light from proton pencil beams against validated Monte Carlo calculations. Blurring due to the lens and refraction at the scintillator tank-air interface were found to have the largest effect on the measured light distribution, and lens aberrations and vignetting were important primarily at the image edges. Photon scatter in the scintillator was not found to be a significant source of artefacts. The correction methods effectively mitigated the artefacts, increasing the average gamma analysis pass rate from 66% to 98% for gamma criteria of 2% dose difference and 2 mm distance to agreement. We conclude that optical artefacts cause clinically meaningful errors in the measured light distribution, and we have demonstrated effective strategies for correcting these optical artefacts. PMID:24321820

  18. Optical artefact characterization and correction in volumetric scintillation dosimetry

    NASA Astrophysics Data System (ADS)

    Robertson, Daniel; Hui, Cheukkai; Archambault, Louis; Mohan, Radhe; Beddar, Sam

    2014-01-01

    The goals of this study were (1) to characterize the optical artefacts affecting measurement accuracy in a volumetric liquid scintillator detector, and (2) to develop methods to correct for these artefacts. The optical artefacts addressed were photon scattering, refraction, camera perspective, vignetting, lens distortion, the lens point spread function, stray radiation, and noise in the camera. These artefacts were evaluated by theoretical and experimental means, and specific correction strategies were developed for each artefact. The effectiveness of the correction methods was evaluated by comparing raw and corrected images of the scintillation light from proton pencil beams against validated Monte Carlo calculations. Blurring due to the lens and refraction at the scintillator tank-air interface were found to have the largest effect on the measured light distribution, and lens aberrations and vignetting were important primarily at the image edges. Photon scatter in the scintillator was not found to be a significant source of artefacts. The correction methods effectively mitigated the artefacts, increasing the average gamma analysis pass rate from 66% to 98% for gamma criteria of 2% dose difference and 2 mm distance to agreement. We conclude that optical artefacts cause clinically meaningful errors in the measured light distribution, and we have demonstrated effective strategies for correcting these optical artefacts.

  19. Development of novel UV emitting single crystalline film scintillators

    NASA Astrophysics Data System (ADS)

    Zorenko, Yu; Gorbenko, V.; Savchyn, V.; Voznyak, T.; Nikl, M.; Mares, J. A.; Martin, T.; Douissard, P.-A.

    2011-04-01

    The work is dedicated to development of new types of UV -emitting scintillators based on single crystalline films (SCF) of aluminimum perovskites and garnets grown by the liquid phase epitaxy (LPE) method. The development of the following three types of UV SCF scintillators is considered in this work: i) Ce-doped SCF of Y-Lu-Al-perovskites with Ce3+ emission in the 360-370 nm range with a decay time of 16-17 ns; ii) Pr-doped SCF of Y-Lu-Al garnets with Pr3+ emission in the 300-400 nm range with a decay time of 13-17 ns; iii) La3+ and Sc3+ doped SCF of Y-Lu-Al-garnets, emitting in the 290-400 nm range due to formation of the LaY,Lu, ScY,Lu and ScAl centers with decay time of 250-575 ns. The results of testing the several novel UV-emitting SCFs scintillators for visualization of X-ray images at ESFR are presented. It is shown that the UV emission of the LuAG:Sc, LuAG:La and LuAG:Pr SCFs is efficient enough for conversion of X-ray to the UV light and that these scintillators can be used for improvement of the resolution of imaging detectors in synchrotron radiation applications.

  20. Scintillator Cosmic Ray Super Telescope

    NASA Astrophysics Data System (ADS)

    González, L. X.; Valdés-Galicia, J. F.; Matsubara, Y.; Nagai, Y.; Itow, Y.; Sako, T.; López, D.; Mitsuka, G.; Munakata, K.; Kato, C.; Yasue, S.; Kosai, M.; Tsurusashi, M.; Nakamo, Y.; Shibata, S.; Takamaru, H.; Kojima, H.; Tsuchiya, H.; Watanabe, K.; Koi, T.; Fragoso, E.; Hurtado, A.; Musalem, O.

    2013-04-01

    The Scintillator Cosmic Ray Super Telescope (SciCRST) is a new experiment to detect solar neutrons, and also it is expected to work as a muon and cosmic ray detector. The SciCRST consist of 14,848 plastic scintillator bars, and it will be installed at the top of Sierra Negra volcano, Mexico, 4580 m.a.s.l. We use a prototype, called as miniSciBar, to test the hardware and software of the final experiment. In this paper, we present the status and details of the experiment, and results of the prototype.

  1. Hygroscopicity Evaluation of Halide Scintillators

    SciTech Connect

    Zhuravleva, M; Stand, L; Wei, H; Hobbs, C. L.; Boatner, Lynn A; Ramey, Joanne Oxendine; Burger, Arnold; Rowe, E; Bhattacharya, P.; Tupitsyn, E; Melcher, Charles L

    2014-01-01

    A collaborative study of relative hygroscopicity of anhydrous halide scintillators grown at various laboratories is presented. We have developed a technique to evaluate moisture sensitivity of both raw materials and grown crystals, in which the moisture absorption rate is measured using a gravimetric analysis. Degradation of the scintillation performance was investigated by recording gamma-ray spectra and monitoring the photopeak position, count rate and energy resolution. The accompanying physical degradation of the samples exposed to ambient atmosphere was photographically recorded as well. The results were compared with ben

  2. Composite scintillators for detection of ionizing radiation

    DOEpatents

    Dai, Sheng [Knoxville, TN; Stephan, Andrew Curtis [Knoxville, TN; Brown, Suree S [Knoxville, TN; Wallace, Steven A [Knoxville, TN; Rondinone, Adam J [Knoxville, TN

    2010-12-28

    Applicant's present invention is a composite scintillator having enhanced transparency for detecting ionizing radiation comprising a material having optical transparency wherein said material comprises nano-sized objects having a size in at least one dimension that is less than the wavelength of light emitted by the composite scintillator wherein the composite scintillator is designed to have selected properties suitable for a particular application.

  3. Characteristics of High Latitude Ionosphere Scintillations

    NASA Astrophysics Data System (ADS)

    Morton, Y.

    2012-12-01

    As we enter a new solar maximum period, global navigation satellite systems (GNSS) receivers, especially the ones operating in high latitude and equatorial regions, are facing an increasing threat from ionosphere scintillations. The increased solar activities, however, also offer a great opportunity to collect scintillation data to characterize scintillation signal parameters and ionosphere irregularities. While there are numerous GPS receivers deployed around the globe to monitor ionosphere scintillations, most of them are commercial receivers whose signal processing mechanisms are not designed to operate under ionosphere scintillation. As a result, they may distort scintillation signal parameters or lose lock of satellite signals under strong scintillations. Since 2008, we have established and continuously improved a unique GNSS receiver array at HAARP, Alaska. The array contains high ends commercial receivers and custom RF front ends which can be automatically triggered to collect high quality GPS and GLONASS satellite signals during controlled heating experiments and natural scintillation events. Custom designed receiver signal tracking algorithms aim to preserve true scintillation signatures are used to process the raw RF samples. Signal strength, carrier phase, and relative TEC measurements generated by the receiver array since its inception have been analyzed to characterize high latitude scintillation phenomena. Daily, seasonal, and solar events dependency of scintillation occurrence, spectral contents of scintillation activities, and plasma drifts derived from these measurements will be presented. These interesting results demonstrate the feasibility and effectiveness of our experimental data collection system in providing insightful details of ionosphere responses to active perturbations and natural disturbances.

  4. Photonic crystal scintillators and methods of manufacture

    DOEpatents

    Torres, Ricardo D.; Sexton, Lindsay T.; Fuentes, Roderick E.; Cortes-Concepcion, Jose

    2015-08-11

    Photonic crystal scintillators and their methods of manufacture are provided. Exemplary methods of manufacture include using a highly-ordered porous anodic alumina membrane as a pattern transfer mask for either the etching of underlying material or for the deposition of additional material onto the surface of a scintillator. Exemplary detectors utilizing such photonic crystal scintillators are also provided.

  5. Measurement of α -particle quenching in LAB based scintillator in independent small-scale experiments

    NASA Astrophysics Data System (ADS)

    von Krosigk, B.; Chen, M.; Hans, S.; Junghans, A. R.; Kögler, T.; Kraus, C.; Kuckert, L.; Liu, X.; Nolte, R.; O'Keeffe, H. M.; Tseung, H. Wan Chan; Wilson, J. R.; Wright, A.; Yeh, M.; Zuber, K.

    2016-03-01

    The α -particle light response of liquid scintillators based on linear alkylbenzene (LAB) has been measured with three different experimental approaches. In the first approach, α -particles were produced in the scintillator via ^{12}C( n,α )^9Be reactions. In the second approach, the scintillator was loaded with 2 % of ^{nat}Sm providing an α -emitter, ^{147}Sm, as an internal source. In the third approach, a scintillator flask was deployed into the water-filled SNO+ detector and the radioactive contaminants ^{222}Rn, ^{218}Po and ^{214}Po provided the α -particle signal. The behavior of the observed α -particle light outputs are in agreement with each case successfully described by Birks' law. The resulting Birks parameter kB ranges from (0.0066± 0.0016) to (0.0076± 0.0003) cm/MeV. In the first approach, the α -particle light response was measured simultaneously with the light response of recoil protons produced via neutron-proton elastic scattering. This enabled a first time a direct comparison of kB describing the proton and the α -particle response of LAB based scintillator. The observed kB values describing the two light response functions deviate by more than 5σ . The presented results are valuable for all current and future detectors, using LAB based scintillator as target, since they depend on an accurate knowledge of the scintillator response to different particles.

  6. Measurement of light yield dependence on electron energy for SNO+ scintillator

    NASA Astrophysics Data System (ADS)

    Wan Chan Tseung, Hok

    2011-10-01

    SNO+ is a multi-purpose neutrino experiment whose reach extends to the following areas of neutrino physics: neutrinoless double beta decay (with Nd-loaded scintillator), geo-neutrinos, reactor and low-energy solar neutrinos, as well as supernova neutrinos. It is a ~780-tonne liquid scintillator detector currently under construction at the SNOLAB facility in Sudbury, Ontario,Canada. The scintillator to be used in SNO+ is linear alkylbenzene (LAB) with ~2 g/L of PPO (2,5-diphenyloxazole). In this talk, we describe an experiment to test the linearity of the response of LAB-PPO with respect to electrons. We find that below ~0.4 MeV, the energy scale of LAB-PPO becomes non-linear. An explanation is given in terms of Cherenkov light absorption and re-emission by the scintillator. This research has been supported under DOE Grant No. DE-FG02-97ER41020.

  7. Melt-cast organic glasses as high-efficiency fast neutron scintillators

    SciTech Connect

    Carlson, Joseph S.; Feng, Patrick L.

    2016-06-24

    In this work we report a new class of organic-based scintillators that combines several of the desirable attributes of existing crystalline, liquid, and plastic organic scintillators. The prepared materials may be isolated in single crystalline form or melt-cast to produce highly transparent glasses that have been shown to provide high light yields of up to 16,000 photons/MeVee, as evaluated against EJ-200 plastic scintillators and solution-grown trans-stilbene crystals. The prepared organic glasses exhibit neutron/gamma pulse-shape discrimination (PSD) and are compatible with wavelength shifters to reduce optical self-absorption effects that are intrinsic to pure materials such as crystalline organics. In conclusion, the combination of high scintillation efficiency, PSD capabilities, and facile scale-up via melt-casting distinguishes this new class of amorphous materials from existing alternatives.

  8. Neutron detection with noble gas scintillation: a review of recent results

    NASA Astrophysics Data System (ADS)

    Lavelle, C. M.; Coplan, Michael; Miller, Eric C.; Thompson, Alan K.; Kowler, Alex; Vest, Rob; Yue, Andrew; Koeth, Tim; Al-Sheikhly, Mohammad; Clark, Charles

    2015-08-01

    Thermal neutron detection is of vital importance to many disciplines, including neutron scattering, workplace monitoring, and homeland protection. We survey recent results from our collaboration which couple low-pressure noble gas scintillation with novel approaches to neutron absorbing materials and geometries to achieve potentially advantageous detector concepts. Noble gas scintillators were used for neutron detection as early as the late 1950's. Modern use of noble gas scintillation includes liquid and solid forms of argon and xenon in the dark matter and neutron physics experiments and commercially available high pressure applications have achieved high resolution gamma ray spectroscopy. Little attention has been paid to the overlap between low pressure noble gas scintillation and thermal neutron detection, for which there are many potential benefits.

  9. Melt-cast organic glasses as high-efficiency fast neutron scintillators

    SciTech Connect

    Carlson, Joseph S.; Feng, Patrick L.

    2016-06-24

    In this work we report a new class of organic-based scintillators that combines several of the desirable attributes of existing crystalline, liquid, and plastic organic scintillators. The prepared materials may be isolated in single crystalline form or melt-cast to produce highly transparent glasses that have been shown to provide high light yields of up to 16,000 photons/MeVee, as evaluated against EJ-200 plastic scintillators and solution-grown trans-stilbene crystals. The prepared organic glasses exhibit neutron/gamma pulse-shape discrimination (PSD) and are compatible with wavelength shifters to reduce optical self-absorption effects that are intrinsic to pure materials such as crystalline organics. In conclusion, the combination of high scintillation efficiency, PSD capabilities, and facile scale-up via melt-casting distinguishes this new class of amorphous materials from existing alternatives.

  10. Melt-cast organic glasses as high-efficiency fast neutron scintillators

    DOE PAGES

    Carlson, Joseph S.; Feng, Patrick L.

    2016-06-24

    In this work we report a new class of organic-based scintillators that combines several of the desirable attributes of existing crystalline, liquid, and plastic organic scintillators. The prepared materials may be isolated in single crystalline form or melt-cast to produce highly transparent glasses that have been shown to provide high light yields of up to 16,000 photons/MeVee, as evaluated against EJ-200 plastic scintillators and solution-grown trans-stilbene crystals. The prepared organic glasses exhibit neutron/gamma pulse-shape discrimination (PSD) and are compatible with wavelength shifters to reduce optical self-absorption effects that are intrinsic to pure materials such as crystalline organics. In conclusion, themore » combination of high scintillation efficiency, PSD capabilities, and facile scale-up via melt-casting distinguishes this new class of amorphous materials from existing alternatives.« less

  11. Extruded plastic scintillator for MINERvA

    SciTech Connect

    Pla-Dalmau, Anna; Bross, Alan D.; Rykalin, Victor V.; Wood, Brian M.; /NICADD, DeKalb

    2005-11-01

    An extrusion line has recently been installed at Fermilab in collaboration with NICADD (Northern Illinois Center for Accelerator and Detector Development). This new facility will serve to further develop and improve extruded plastic scintillator. Since polystyrene is widely used in the consumer industry, the logical path was to investigate the extrusion of commercial-grade polystyrene pellets with dopants to yield high quality plastic scintillator. The D0 and MINOS experiments are already using extruded scintillator strips in their detectors. A new experiment at Fermilab is pursuing the use of extruded plastic scintillator. A new plastic scintillator strip is being tested and its properties characterized. The initial results are presented here.

  12. Method of making a scintillator waveguide

    DOEpatents

    Bliss, Mary; Craig, Richard A.; Reeder, Paul L.

    2000-01-01

    The present invention is an apparatus for detecting ionizing radiation, having: a waveguide having a first end and a second end, the waveguide formed of a scintillator material wherein the therapeutic ionizing radiation isotropically generates scintillation light signals within the waveguide. This apparatus provides a measure of radiation dose. The apparatus may be modified to permit making a measure of location of radiation dose. Specifically, the scintillation material is segmented into a plurality of segments; and a connecting cable for each of the plurality of segments is used for conducting scintillation signals to a scintillation detector.

  13. Complex Dynamics of Equatorial Scintillation

    NASA Astrophysics Data System (ADS)

    Piersanti, Mirko; Materassi, Massimo; Forte, Biagio; Cicone, Antonio

    2017-04-01

    Radio power scintillation, namely highly irregular fluctuations of the power of trans-ionospheric GNSS signals, is the effect of ionospheric plasma turbulence. The scintillation patterns on radio signals crossing the medium inherit the ionospheric turbulence characteristics of inter-scale coupling, local randomness and large time variability. On this basis, the remote sensing of local features of the turbulent plasma is feasible by studying radio scintillation induced by the ionosphere. The distinctive character of intermittent turbulent media depends on the fluctuations on the space- and time-scale statistical properties of the medium. Hence, assessing how the signal fluctuation properties vary under different Helio-Geophysical conditions will help to understand the corresponding dynamics of the turbulent medium crossed by the signal. Data analysis tools, provided by complex system science, appear to be best fitting to study the response of a turbulent medium, as the Earth's equatorial ionosphere, to the non-linear forcing exerted by the Solar Wind (SW). In particular we used the Adaptive Local Iterative Filtering, the Wavelet analysis and the Information theory data analysis tool. We have analysed the radio scintillation and ionospheric fluctuation data at low latitude focusing on the time and space multi-scale variability and on the causal relationship between forcing factors from the SW environment and the ionospheric response.

  14. Light Collection in Liquid Noble Gases

    SciTech Connect

    McKinsey, Dan

    2013-05-29

    Liquid noble gases are increasingly used as active detector materials in particle and nuclear physics. Applications include calorimeters and neutrino oscillation experiments as well as searches for neutrinoless double beta decay, direct dark matter, muon electron conversion, and the neutron electric dipole moment. One of the great advantages of liquid noble gases is their copious production of ultraviolet scintillation light, which contains information about event energy and particle type. I will review the scintillation properties of the various liquid noble gases and the means used to collect their scintillation light, including recent advances in photomultiplier technology and wavelength shifters.

  15. Organic scintillators with pulse shape discrimination for detection of radiation (Conference Presentation)

    NASA Astrophysics Data System (ADS)

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

    2016-09-01

    The detection of neutrons in the presence of gamma-ray fields has important applications in the fields of nuclear physics, homeland security, and medical imaging. Organic scintillators provide several attractive qualities as neutron detection materials including low cost, fast response times, ease of scaling, and the ability to implement pulse shape discrimination (PSD) to discriminate between neutrons and gamma-rays. This talk will focus on amorphous organic scintillators both in plastic form and small-molecule organic glass form. The first section of this talk will describe recent advances and improvements in the performance of PSD-capable plastic scintillators. The primary advances described in regard to modification of the polymer matrix, evaluation of new scintillating dyes, improved fabrication conditions, and implementation of additives which impart superior performance and mechanical properties to PSD-capable plastics as compared to commercially-available plastics and performance comparable to PSD-capable liquids. The second section of this talk will focus on a class of small-molecule organic scintillators based on modified indoles and oligophenylenes which form amorphous glasses as PSD-capable neutron scintillation materials. Though indoles and oligophenylenes have been known for many decades, their PSD properties have not been investigated and their scintillation properties only scantily investigated. Well-developed synthetic methodologies have permitted the synthesis of a library of structural analogs of these compounds as well as the investigation of their scintillation properties. The emission wavelengths of many indoles are in the sensitive region of common photomultiplier tubes, making them appropriate to be used as scintillators in either pure or doped form. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. This work has been supported by the U

  16. Neutron response characterization for an EJ299-33 plastic scintillation detector

    DOE PAGES

    Lawrence, Chris C.; Febbraro, Michael; Massey, Thomas N.; ...

    2014-05-10

    Organic scintillation detectors have shown promise as neutron detectors for characterizing special nuclear materials in various arms-control and homeland security applications. Recent advances have yielded a new plastic scintillator - EJ299-33 - with pulse-shape-discrimination (PSD) capability. Plastic scintillators would have a much expanded range of deployment relative to liquids and crystals. Here in this paper, we present a full characterization of pulse height response to fission-energy neutrons for an EJ299-33 detector with 7.62-by-7.62-cm cylindrical active volume, and compare with an EJ309 liquid scintillator in the same assembly. Scintillation light output relations, energy resolutions, and response matrices are presented for bothmore » detectors. A Continuous spectrum neutron source, obtained via the bombardment of 27Al with 7.44-MeV deuterons at the Edwards Accelerator Facility at Ohio University, was used for the measurement. A new procedure for evaluating and comparing PSD performance is presented which accounts for the effect of the light output relation on the ability to detect low energy neutrons. The EJ299-33 is shown to have considerable deficit in matrix condition, and in PSD figure of merit when compared to EJ309, especially when neutron energy is taken into account. Furthermore the EJ299 is likely to bring a modest PSD capability into a array of held applications that are not accessible to liquids or crystals.« less

  17. Neutron response characterization for an EJ299-33 plastic scintillation detector

    SciTech Connect

    Lawrence, Chris C.; Febbraro, Michael; Massey, Thomas N.; Flaska, Marek; Becchetti, F. D.; Pozzi, Sara A.

    2014-05-10

    Organic scintillation detectors have shown promise as neutron detectors for characterizing special nuclear materials in various arms-control and homeland security applications. Recent advances have yielded a new plastic scintillator - EJ299-33 - with pulse-shape-discrimination (PSD) capability. Plastic scintillators would have a much expanded range of deployment relative to liquids and crystals. Here in this paper, we present a full characterization of pulse height response to fission-energy neutrons for an EJ299-33 detector with 7.62-by-7.62-cm cylindrical active volume, and compare with an EJ309 liquid scintillator in the same assembly. Scintillation light output relations, energy resolutions, and response matrices are presented for both detectors. A Continuous spectrum neutron source, obtained via the bombardment of 27Al with 7.44-MeV deuterons at the Edwards Accelerator Facility at Ohio University, was used for the measurement. A new procedure for evaluating and comparing PSD performance is presented which accounts for the effect of the light output relation on the ability to detect low energy neutrons. The EJ299-33 is shown to have considerable deficit in matrix condition, and in PSD figure of merit when compared to EJ309, especially when neutron energy is taken into account. Furthermore the EJ299 is likely to bring a modest PSD capability into a array of held applications that are not accessible to liquids or crystals.

  18. Cosmic ray scintillations. II - General theory of interplanetary scintillations

    NASA Technical Reports Server (NTRS)

    Owens, A. J.

    1974-01-01

    The motion of charged particles in a stochastic magnetic field with nonzero mean is considered via a generalized quasi-linear expansion of Liouville's equation. The general result is an equation relating cosmic ray scintillations to magnetic fluctuations and to cosmic ray gradients. The resonant interaction between particles and the random magnetic field is considered in detail, and the effect of nonlinear terms in the equations is considered. The nonlinear terms are important in damping out initial conditions and in determining conditions near cyclotron resonances. The application of the theory to the propagation of cosmic rays during quiet times in interplanetary space is considered. It is concluded that cosmic ray scintillations in interplanetary space may provide useful information about interplanetary particles and fields and also about nonlinear plasma interactions.

  19. Scintillation Monitoring Using Asymmetry Index

    NASA Astrophysics Data System (ADS)

    Shaikh, Muhammad Mubasshir; Mahrous, Ayman; Abdallah, Amr; Notarpietro, Riccardo

    Variation in electron density can have significant effect on GNSS signals in terms of propagation delay. Ionospheric scintillation can be caused by rapid change of such delay, specifically, when they last for a longer period of time. Ionospheric irregularities that account for scintillation may vary significantly in spatial range and drift with the background plasma at speeds of 45 to 130 m/sec. These patchy irregularities may occur several times during night, e.g. in equatorial region, with the patches move through the ray paths of the GNSS satellite signals. These irregularities are often characterized as either ‘large scale’ (which can be as large as several hundred km in East-West direction and many times that in the North-South direction) or ‘small scale’ (which can be as small as 1m). These small scale irregularities are regarded as the main cause of scintillation [1,2]. In normal solar activity conditions, the mid-latitude ionosphere is not much disturbed. However, during severe magnetic storms, the aurora oval extends towards the equator and the equator anomaly region may stretched towards poles extending the scintillation phenomena more typically associated with those regions into mid-latitudes. In such stormy conditions, the predicted TEC may deviate largely from the true value of the TEC both at low and mid-latitudes due to which GNSS applications may be strongly degraded. This work is an attempt to analyze ionospheric scintillation (S4 index) using ionospheric asymmetry index [3]. The asymmetry index is based on trans-ionospheric propagation between GPS and LEO satellites in a radio occultation (RO) scenario, using background ionospheric data provided by MIDAS [4]. We attempted to simulate one of the recent geomagnetic storms (NOAA scale G4) occurred over low/mid-latitudes. The storm started on 26 September 2011 at UT 18:00 and lasted until early hours of 27 September 2011. The scintillation data for the storm was taken from an ionospheric

  20. LHCb Upgrade: Scintillating Fibre Tracker

    NASA Astrophysics Data System (ADS)

    Tobin, Mark; LHCb Upgrade Scintillating Fibre Tracker Group

    2016-07-01

    The LHCb detector will be upgraded during the Long Shutdown 2 (LS2) of the LHC in order to cope with higher instantaneous luminosities and to read out the data at 40 MHz using a trigger-less read-out system. All front-end electronics will be replaced and several sub-detectors must be redesigned to cope with higher occupancy. The current tracking detectors downstream of the LHCb dipole magnet will be replaced by the Scintillating Fibre (SciFi) Tracker. The SciFi Tracker will use scintillating fibres read out by Silicon Photomultipliers (SiPMs). State-of-the-art multi-channel SiPM arrays are being developed to read out the fibres and a custom ASIC will be used to digitise the signals from the SiPMs. The evolution of the design since the Technical Design Report in 2014 and the latest R & D results are presented.

  1. Scintillation Forecasting Using NPOESS Data

    NASA Astrophysics Data System (ADS)

    Basu, B.; Retterer, J.; Demajistre, R.; de La Beaujardiere, O.; Scro, K.

    2005-12-01

    We have conducted a theoretical study of the use of NPOESS data for the forecasting of equatorial radio scintillation using knowledge of the equatorial Appleton anomaly, e.g., the peak-to-valley ratio of TEC (Total Electron Content) between the anomaly crests and the magnetic equator. The peak-to-valley ratio can be obtained from the UV (ultraviolet) imagery of the anomaly region that will be provided by the NPOESS sensors. The post-sunset enhancement of the upward drift velocity of the equatorial plasma has been shown, both theoretically and observationally, to be an important determinant of both the onset of scintillation and the strength of the anomaly. The technical approach is to run PBMOD, the AFRL low-latitude ionosphere model, with a range of post-sunset vertical drift velocities to determine the quantitative relationship between the peak-to-valley ratio and the maximum value of the pot-sunset upward drift velocity of equatorial plasma. Once the relationship is validated, it will be used to estimate the maximum value of the drift velocity from the peak-to-valley ratio, which is derived from the UV imagery data provided by NPOESS-like sensor, such as GUVI on TIMED satellite. The drift velocity will then be used in PBMOD to simulate the formation and evolution of equatorial plasma `bubbles' and calculate the distribution of the amplitude scintillation index S4. Results of the study will be discussed.

  2. Scintillation Reduction Method for Photometric Measurements

    NASA Astrophysics Data System (ADS)

    Ryan, P.; Sandler, D.

    1998-10-01

    We explore the reduction of scintillation via differencing signals from binary stars. Theory has been extended to include temporal and angular separation effects simultaneously. For meter-class telescopes, scintillation for a 2" binary is reduced by greater than a factor of 3. Aperture averaging for differential scintillation had a D^-1.4+/-0.1 dependence for exposure times <=0.25 s versus D^-1.1+/-0.1 for absolute scintillation. For 1.5 m diameter telescopes, the influence of binary separation on differential scintillation for theta<5^'' went as theta^0.6 for instantaneous scintillation and rose slightly with exposure time. If the deconvolution problem can be solved, differencing signals from binary stars offers the potential for increased photometric accuracy.

  3. A Review of Ionospheric Scintillation Models

    NASA Astrophysics Data System (ADS)

    Priyadarshi, S.

    2015-03-01

    This is a general review of the existing climatological models of ionospheric radio scintillation for high and equatorial latitudes. Trans-ionospheric communication of radio waves from transmitter to user is affected by the ionosphere which is highly variable and dynamic in both time and space. Scintillation is the term given to irregular amplitude and phase fluctuations of the received signals and related to the electron density irregularities in the ionosphere. Key sources of ionospheric irregularities are plasma instabilities; every irregularities model is based on the theory of radio wave propagation in random media. It is important to understand scintillation phenomena and the approach of different theories. Therefore, we have briefly discussed the theories that are used to interpret ionospheric scintillation data. The global morphology of ionospheric scintillation is also discussed briefly. The most important (in our opinion) analytical and physical models of scintillation are reviewed here.

  4. A Review of Ionospheric Scintillation Models.

    PubMed

    Priyadarshi, S

    This is a general review of the existing climatological models of ionospheric radio scintillation for high and equatorial latitudes. Trans-ionospheric communication of radio waves from transmitter to user is affected by the ionosphere which is highly variable and dynamic in both time and space. Scintillation is the term given to irregular amplitude and phase fluctuations of the received signals and related to the electron density irregularities in the ionosphere. Key sources of ionospheric irregularities are plasma instabilities; every irregularities model is based on the theory of radio wave propagation in random media. It is important to understand scintillation phenomena and the approach of different theories. Therefore, we have briefly discussed the theories that are used to interpret ionospheric scintillation data. The global morphology of ionospheric scintillation is also discussed briefly. The most important (in our opinion) analytical and physical models of scintillation are reviewed here.

  5. Morphology of auroral zone radio wave scintillation

    SciTech Connect

    Rino, C.L.; Matthews, S.J.

    1980-08-01

    This paper describes the morphology of midnight sector and morning sector auroral zone scintillation observations made over a two-year period using the Wideband satelite, which is in a sun-synchronous, low-altitude orbit. No definitive seasonal variation was found. The nighttime data showed the highest scintillation ocurrence levels, but significant amounts of morning scintillation were observed. For the most part the scintillation activity followed the general pattern of local magnetic activity. The most prominent feature in the nightime data is a localized amplitude and phase scintillation enhancement at the point where the propagation vector lies within an L shell. A geometrical effect due to a dynamic slab of sheetlike structures in the F region is hypothesized as the source of his enhancement. The data have been sorted by magnetic activity, proximity to local midnight, and season. The general features of the data are in agreement with the accepted morphology of auroral zone scintillation.

  6. Development of new scintillators for medical applications

    NASA Astrophysics Data System (ADS)

    Lecoq, Paul

    2016-02-01

    For a long time the discovery of new scintillators has been more serendipitous than driven by a deep understanding of the mechanisms at the origin of the scintillation process. This situation has dramatically changed since the 1990's with an increased demand for scintillators of better performance for large particle physics experiments as well as for medical imaging. It is now possible to design a scintillator for a specific purpose. The bandgap can be adjusted, the traps energy levels and their concentration can be finely tuned and their influence can be damped or on the contrary enhanced by specific doping for an optimization of the performance of the scintillator. Several examples are given in this paper of such crystal engineering attempts to improve the performance of crystal scintillators used in medical imaging devices. An attention is also given to spectacular progress in crystal production technologies, which open new perspectives for large scale and cost effective crystal production with consistent quality.

  7. Study of phenylxylylethane (PXE) as scintillator for low energy neutrino experiments

    NASA Astrophysics Data System (ADS)

    Back, H. O.; Balata, M.; de Bari, A.; Beau, T.; de Bellefon, A.; Bellini, G.; Benziger, J.; Bonetti, S.; Brigatti, A.; Buck, C.; Caccianiga, B.; Cadonati, L.; Calaprice, F.; Cecchet, G.; Chen, M.; Di Credico, A.; Dadoun, O.; D'Angelo, D.; Derbin, A.; Deutsch, M.; Elisei, F.; Etenko, A.; von Feilitzsch, F.; Fernholz, R.; Ford, R.; Franco, D.; Freudiger, B.; Galbiati, C.; Gatti, F.; Gazzana, S.; Giammarchi, M. G.; Giugni, D.; Göger-Neff, M.; Goretti, A.; Grieb, C.; de Haas, E.; Hagner, C.; Hampel, W.; Harding, E.; Hartmann, F. X.; Hertrich, T.; Hess, H.; Heusser, G.; Ianni, A.; Ianni, A. M.; de Kerret, H.; Kiko, J.; Kirsten, T.; Korga, G.; Korschinek, G.; Kozlov, Y.; Kryn, D.; Laubenstein, M.; Lendvai, C.; Loeser, F.; Lombardi, P.; Malvezzi, S.; Maneira, J.; Manno, I.; Manuzio, D.; Manuzio, G.; Masetti, F.; Martemianov, A.; Mazzucato, U.; McCarty, K.; Meroni, E.; Miramonti, L.; Monzani, M. E.; Musico, P.; Niedermeier, L.; Oberauer, L.; Obolensky, M.; Ortica, F.; Pallavicini, M.; Papp, L.; Parmeggiano, S.; Perasso, L.; Pocar, A.; Raghavan, R. S.; Ranucci, G.; Rau, W.; Razeto, A.; Resconi, E.; Sabelnikov, A.; Salvo, C.; Scardaoni, R.; Schimizzi, D.; Schönert, S.; Schuhbeck, K. H.; Seitz, E.; Simgen, H.; Shutt, T.; Skorokhvatov, M.; Smirnov, O.; Sonnenschein, A.; Sotnikov, A.; Sukhotin, S.; Tarasenkov, V.; Tartaglia, R.; Testera, G.; Vignaud, D.; Vogelaar, R. B.; Vyrodov, V.; Wojcik, M.; Zaimidoroga, O.; Zuzel, G.

    2008-01-01

    We report on the study of a new liquid scintillator target for neutrino interactions in the framework of the research and development program of the Borexino solar neutrino experiment. The scintillator consists of 1,2-dimethyl-4-(1-phenylethyl)-benzene (phenyl-o-xylylethane, PXE) as solvent and 1,4-diphenylbenzene (para-Terphenyl, p-Tp) as primary and 1,4-bis(2-methylstyryl)benzene (bis-MSB) as secondary solute. The density close to that of water and the high flash point makes it an attractive option for large scintillation detectors in general. The study focused on optical properties, radioactive trace impurities and novel purification techniques of the scintillator. Attenuation lengths of the scintillator mixture of 12 m at 430 nm were achieved after purification with an alumina column. A radiocarbon isotopic ratio of C14/C12=9.1×10-18 has been measured in the scintillator. Initial trace impurities, e.g. 238U at 3.2×10-14 g/g could be purified to levels below 1×10-17 g/g by silica gel solid column purification.

  8. Separation and subsequent determination of low radioactivity levels of radium by extraction scintillation.

    PubMed

    Borai, E H; Lasheen, Y F; El-Sofany, E A; Abdel-Rassoul, A A

    2008-08-15

    A method is developed for separation and subsequent determination of low (226)Ra levels based on its extraction efficiency by various organic extractants followed by direct interaction with mixed scintillation cocktail (SC) in toluene as the most suitable solvent. Three organic extractants including Tricaprylmethyleammonium chloride (Aliquat-336), triphenylphosphine sulphide (TPPS) and tri-n-octylphosphine oxide (TOPO) are individually embedded in 1-phenyl,4-phenyloxazole (PPO) as a primary scintillator and 1,4-di-2-(4-methyl, 5-phenyl oxazoyl) benzene (POPOP) as a second scintillator. Different parameters affecting the extraction process including shaking time, type and concentration of extractant, aqueous/organic volume ratio as well as various levels of (226)Ra are individually investigated. Based on the optimized condition, it was found that the extraction of (226)Ra by Aliquat-336 is highly selective with efficient separation capability from (133)Ba, which is necessary to determine the yield and recovery of (226)Ra in related measurements. The combination of extraction with direct scintillation processes is mainly elaborated to overcome the heterogeneity problem and hence the slow scintillation rate that often exists in conventional liquid scintillation counting especially with low radioactivity levels.

  9. Scintillator tiles read out with silicon photomultipliers

    NASA Astrophysics Data System (ADS)

    Pooth, O.; Radermacher, T.; Weingarten, S.; Weinstock, L.

    2015-10-01

    A detector prototype based on a fast plastic scintillator read out with silicon photomultipliers is presented. All studies have been done with cosmic muons and focus on parameter optimization such as coupling the SiPM to the scintillator or wrapping the scintillator with reflective material. The prototype shows excellent results regarding the light-yield and offers a detection efficiency of 99.5% with a signal purity of 99.9% for cosmic muons.

  10. Holes: Ionospheric Scintillation, GPS and Imputation

    DTIC Science & Technology

    2007-03-01

    HOLES: IONOSPHERIC SCINTILLATION GPS AND IMPUTATION THESIS Robert A. Steenburgh, Senior Master Sergeant, USAF AFIT/GAP/ENP/07-06 DEPARTMENT OF THE...of Defense, or the United States Government. AFIT/GAP/ENP/07-06 HOLES: IONOSPHERIC SCINTILLATION GPS AND IMPUTATION THESIS Presented to the Faculty...Master Sergeant, USAF March 2007 APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED. AFIT/GAP/ENP/07-06 HOLES: IONOSPHERIC SCINTILLATION GPS AND

  11. Neutron position-sensitive scintillation detector

    DOEpatents

    Strauss, Michael G.; Brenner, Raul

    1984-01-01

    A device is provided for mapping one- and two-dimensional distributions of neutron-positions in a scintillation detector. The device consists of a lithium glass scintillator coupled by an air gap and a light coupler to an array of photomultipliers. The air gap concentrates light flashes from the scintillator, whereas the light coupler disperses this concentrated light to a predetermined fraction of the photomultiplier tube array.

  12. Low-cost extruded plastic scintillator

    NASA Astrophysics Data System (ADS)

    Pla-Dalmau, Anna; Bross, Alan D.; Mellott, Kerry L.

    2001-07-01

    Motivated by a need for lower cost plastic scintillation detectors, we have tested commercially available polystyrene pellets in order to produce scintillating materials that can be extruded into various shapes. Selection of the raw materials is discussed. Two techniques are described that add wavelength shifting dopants to polystyrene pellets and extrude plastic scintillating bars using these materials. Data on light yield and transmittance are presented.

  13. Recording of relativistic particles in thin scintillators

    SciTech Connect

    Tolstukhin, I A.; Somov, Alexander S.; Somov, S. V.; Bolozdynya, A. I.

    2014-11-01

    Results of investigating an assembly of thin scintillators and silicon photomultipliers for registering relativistic particles with the minimum ionization are presented. A high efficiency of registering relativistic particles using an Ej-212 plastic scintillator, BSF-91A wavelength-shifting fiber (Saint-Gobain), and a silicon photomultiplier (Hamamtsu) is shown. The measurement results are used for creating a scintillation hodoscope of the magnetic spectrometer for registering γ quanta in the GlueX experiment.

  14. Spacecraft Radio Scintillation and Solar System Exploration

    NASA Technical Reports Server (NTRS)

    Woo, Richard

    1993-01-01

    When a wave propagates through a turbulent medium, scattering by the random refractive index inhomogeneities can lead to a wide variety of phenomena that have been the subject of extensive study. The observed scattering effects include amplitude or intensity scintillation, phase scintillation, angular broadening, and spectral broadening, among others. In this paper, I will refer to these scattering effects collectively as scintillation. Although the most familiar example is probably the twinkling of stars (light wave intensity scintillation by turbulence in the Earth's atmosphere), scintillation has been encountered and investigated in such diverse fields as ionospheric physics, oceanography, radio astronomy, and radio and optical communications. Ever since planetary spacecraft began exploring the solar system, scintillation has appeared during the propagation of spacecraft radio signals through planetary atmospheres, planetary ionospheres, and the solar wind. Early studies of these phenomena were motivated by the potential adverse effects on communications and navigation, and on experiments that use the radio link to conduct scientific investigations. Examples of the latter are radio occultation measurements (described below) of planetary atmospheres to deduce temperature profiles, and the search for gravitational waves. However,these concerns soon gave way to the emergence of spacecraft radio scintillation as a new scientific tool for exploring small-scale dynamics in planetary atmospheres and structure in the solar wind, complementing in situ and other remote sensing spacecraft measurements, as well as scintillation measurements using natural (celestial) radio sources. The purpose of this paper is to briefly describe and review the solar system spacecraft radio scintillation observations, to summarize the salient features of wave propagation analyses employed in interpreting them, to underscore the unique remote sensing capabilities and scientific relevance of

  15. Divalent fluoride doped cerium fluoride scintillator

    DOEpatents

    Anderson, David F.; Sparrow, Robert W.

    1991-01-01

    The use of divalent fluoride dopants in scintillator materials comprising cerium fluoride is disclosed. The preferred divalent fluoride dopants are calcium fluoride, strontium fluoride, and barium fluoride. The preferred amount of divalent fluoride dopant is less than about two percent by weight of the total scintillator. Cerium fluoride scintillator crystals grown with the addition of a divalent fluoride have exhibited better transmissions and higher light outputs than crystals grown without the addition of such dopants. These scintillators are useful in radiation detection and monitoring applications, and are particularly well suited for high-rate applications such as positron emission tomography (PET).

  16. High-symmetry organic scintillator systems

    DOEpatents

    Feng, Patrick L.

    2017-06-14

    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.

  17. Radio wave scintillations at equatorial regions

    NASA Technical Reports Server (NTRS)

    Poularikas, A. D.

    1972-01-01

    Radio waves, passing through the atmosphere, experience amplitude and phase fluctuations know as scintillations. A characterization of equatorial scintillation, which has resulted from studies of data recorded primarily in South America and equatorial Africa, is presented. Equatorial scintillation phenomena are complex because they appear to vary with time of day (pre-and postmidnight), season (equinoxes), and magnetic activity. A wider and more systematic geographical coverage is needed for both scientific and engineering purposes; therefore, it is recommended that more observations should be made at earth stations (at low-geomagnetic latitudes) to record equatorial scintillation phenomena.

  18. High-symmetry organic scintillator systems

    DOEpatents

    Feng, Patrick L.

    2017-09-05

    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.

  19. High-symmetry organic scintillator systems

    DOEpatents

    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.

  20. Performance of wavefront sensors in strong scintillation

    NASA Astrophysics Data System (ADS)

    Barchers, Jeffrey D.; Fried, David L.; Link, Donald J.; Tyler, Glenn A.; Moretti, William; Brennan, Terry J.; Fugate, Robert Q.

    2003-02-01

    The estimation accuracy of wavefront sensors in strong scintillation is examined. Wave optical simulation is used to characterize the performance of several wavefront sensors in the absence of measurement noise. The estimation accuracy of a Schack-Hartmann sensor is shown to be poor in strong scintillation due primarily to the presence of branch points in the phase function. The estimation accuracy of a unit-shear, shearing interferometer is found to be significantly better than that of a Hartmann sensor in strong scintillation. The estimation accuracy of a phase shifting point diffraction interferometer is shown to be invariant with scintillation.

  1. Gaseous photomultipliers for the readout of scintillators and detection Cherenkov radiation

    SciTech Connect

    Peskov, V.; Borovik-Romanov, A.

    1993-11-01

    The latest achievements in the development of gaseous detectors for registering UV and visible photons are described. Possible modifications of their design for some particular applications such as the readout of crystal scintillators. noble liquids, fibers and for large area Cherenkov detectors are discussed.

  2. Scalability, Scintillation Readout and Charge Drift in a Kilogram Scale Solid Xenon Particle Detector

    SciTech Connect

    Yoo, J.; Cease, H.; Jaskierny, W. F.; Markley, D.; Pahlka, R. B.; Balakishiyeva, D.; Saab, T.; Filipenko, M.

    2014-10-23

    We report a demonstration of the scalability of optically transparent xenon in the solid phase for use as a particle detector above a kilogram scale. We employ a liquid nitrogen cooled cryostat combined with a xenon purification and chiller system to measure the scintillation light output and electron drift speed from both the solid and liquid phases of xenon. Scintillation light output from sealed radioactive sources is measured by a set of high quantum efficiency photomultiplier tubes suitable for cryogenic applications. We observed a reduced amount of photons in solid phase compared to that in liquid phase. We used a conventional time projection chamber system to measure the electron drift time in a kilogram of solid xenon and observed faster electron drift speed in the solid phase xenon compared to that in the liquid phase.

  3. Accelerated discovery of elpasolite scintillators

    SciTech Connect

    Doty, F. Patrick; Yang, Pin; Zhou, Xiaowang

    2014-12-01

    Elpasolite scintillators are a large family of halides which includes compounds reported to meet the NA22 program goals of <3% energy resolution at 662 keV1. This work investigated the potential to produce quality elpasolite compounds and alloys of useful sizes at reasonable cost, through systematic experimental and computational investigation of crystal structure and properties across the composition space. Discovery was accelerated by computational methods and models developed previously to efficiently identify cubic members of the elpasolite halides, and to evaluate stability of anion and cation exchange alloys.

  4. Photodetectors for Scintillator Proportionality Measurement

    SciTech Connect

    Moses, William W.; Choong, Woon-Seng; Hull, Giulia; Payne, Steve; Cherepy, Nerine; Valentine, J.D.

    2010-10-18

    We evaluate photodetectors for use in a Compton Coincidence apparatus designed for measuring scintillator proportionality. There are many requirements placed on the photodetector in these systems, including active area, linearity, and the ability to accurately measure low light levels (which implies high quantum efficiency and high signal-to-noise ratio). Through a combination of measurement and Monte Carlo simulation, we evaluate a number of potential photodetectors, especially photomultiplier tubes and hybrid photodetectors. Of these, we find that the most promising devices available are photomultiplier tubes with high ({approx}50%) quantum efficiency, although hybrid photodetectors with high quantum efficiency would be preferable.

  5. A Scintillating Fibre Tracker for MICE

    NASA Astrophysics Data System (ADS)

    Ellis, Malcolm

    The provision of intense stored muon beams would allow the properties of neutrinos to be measured precisely and provide a route to multi-TeV lepton-anti-lepton collisions. The short muon lifetime makes it impossible to employ traditional cooling techniques while maintaining the muon-beam intensity. Ionisation cooling, a process in which the muon beam is passed through a series of liquid hydrogen absorbers followed by accelerating RF-cavities, is the proposed cooling technique. The international Muon Ionisation Cooling Experiment (MICE) collaboration has been approved at the Rutherford Appleton Laboratory and proposes to perform an engineering demonstration of ionisation cooling. The MICE experiment will require the measurement of the momentum and position of muons entering and leaving a section of ionisation cooling channel with high precision and purity in the presence of a large background. The technology chosen to meet this challenge is scintillating fibres readout with Visible Light Photon Detectors. The design, construction and operation of a prototype detector is described, as well as a summary of ongoing research and development activities in preparation for supplying the trackers needed for the MICE experiment.

  6. Epoxy resins produce improved plastic scintillators

    NASA Technical Reports Server (NTRS)

    Markley, F. W.

    1967-01-01

    Plastic scintillator produced by the substitution of epoxy resins for the commonly used polystyrene is easy to cast, stable at room temperature, and has the desirable properties of a thermoset or cross-linked system. Such scintillators can be immersed directly in strong solvents, an advantage in many chemical and biological experiments.

  7. Scintillator handbook with emphasis on cesium iodide

    NASA Technical Reports Server (NTRS)

    Tidd, J. L.; Dabbs, J. R.; Levine, N.

    1973-01-01

    This report provides a background of reasonable depth and reference material on scintillators in general. Particular attention is paid to the cesium iodide scintillators as used in the High Energy Astronomy Observatory (HEAO) experiments. It is intended especially for use by persons such as laboratory test personnel who need to obtain a working knowledge of these materials and their characteristics in a short time.

  8. Binderless composite scintillator for neutron detection

    DOEpatents

    Hodges, Jason P [Knoxville, TN; Crow, Jr; Lowell, M [Oak Ridge, TN; Cooper, Ronald G [Oak Ridge, TN

    2009-03-10

    Composite scintillator material consisting of a binderless sintered mixture of a Lithium (Li) compound containing .sup.6Li as the neutron converter and Y.sub.2SiO.sub.5:Ce as the scintillation phosphor, and the use of this material as a method for neutron detection. Other embodiments of the invention include various other Li compounds.

  9. The Temporal Structure of Strongly Scintillating Signals.

    DTIC Science & Technology

    1979-01-31

    referred to as "equatorial spread-F." The discovery of gigahertz scintillation (Craft and Westerlund , 1972) was II unexpected, although nighttime...and L. H. Westerlund , "Scintillations at 4 and 6 GHz Caused by the Ionosphere," paper presented at AIAA 10th Aerospace Sciences Meeting, San Diego

  10. Current status on plastic scintillators modifications

    SciTech Connect

    Hamel, Matthieu; Bertrand, Guillaume H.V.; Carrel, Frederick; Coulon, Romain; Dumazert, Jonathan; Montbarbon, Eva; Sguerra, Fabien

    2015-07-01

    Recent developments of plastic scintillators are reviewed, from 2000 to March 2015. All examples are distributed into the main purpose, i.e. the nature of the radionuclide provided with the scope of detection of various radiation particles. The main characteristics of these newly created scintillators and their detection properties are given. (authors)

  11. A scintillation playback system for quantum links

    NASA Astrophysics Data System (ADS)

    Rabinovich, William S.; Mahon, Rita; Bashkansky, Mark; Freeman, Rachel; Reintjes, John

    2017-02-01

    Quantum key distribution (QKD) using free space optical (FSO) systems will, in most applications, involve atmospheric propagation. As is well known from classical FSO communication links, turbulence can cause large power variation in the link strength. Optical scintillation can cause fades below and surges above the mean power that last tens of milliseconds. Fades can be as deep as 20-30 dB. Previously we have demonstrated a system that allows laboratory studies of the effects of scintillation that faithfully represent the effects seen in the field. Scintillation is recorded using a modified FSO system and then played back in the laboratory using a fiber optic based system. The result is a laboratory experiment that reproduces, with high fidelity, the field conditions and component performance of the actual link. We have applied this same technique to studying scintillation effects on a QKD link. Scintillation was recorded at the US Naval Research Laboratory's Maritime Lasercom Testbed This facility has sites on both sides of Chesapeake Bay separated by 16 km. A single-photon scintillation playback system was constructed. This scintillation playback system was designed to implement a BB84 protocol, but other QKD protocols could also be used. After the playback experiment the data can be analyzed to determine key length, error rate and other parameters. The set up can be used to study a variety of protocols for QKD in scintillation. Application to studies such as this will be presented.

  12. Prospects of the search for neutrino bursts from supernovae with Baksan large volume scintillation detector

    NASA Astrophysics Data System (ADS)

    Petkov, V. B.

    2016-11-01

    Observing a high-statistics neutrino signal from the supernova explosions in the Galaxy is a major goal of low-energy neutrino astronomy. The prospects for detecting all flavors of neutrinos and antineutrinos from the core-collapse supernova (ccSN) in operating and forthcoming large liquid scintillation detectors (LLSD) are widely discussed now. One of proposed LLSD is Baksan Large Volume Scintillation Detector (BLVSD). This detector will be installed at the Baksan Neutrino Observatory (BNO) of the Institute for Nuclear Research, Russian Academy of Sciences, at a depth of 4800 m.w.e. Low-energy neutrino astronomy is one of the main lines of research of the BLVSD.

  13. Luminescent and scintillation properties of YAG:Tm and YAG:Ce,Tm single crystalline films

    NASA Astrophysics Data System (ADS)

    Zorenko, Yu.; Gorbenko, V.; Savchyn, V.; Suchocki, A.; Wrzesinski, H.; Walczyk, K.; Fabisiak, K.; Bilski, P.; Twardak, A.

    2014-08-01

    The paper is dedicated to studying the luminescent and scintillation properties of the single crystalline films (SCF) of Tm and Tm-Ce doped Y3Al5O12 garnets grown by the liquid phase epitaxy method. We have found that the effective Tm → Ce energy transfer is observed in YAG:Ce,Tm SCF. As a result of such transfer, the scintillation light yield of YAG:Ce,Tm SCF under α-particles excitation can be large in comparison with YAG:Ce SCF counterpart.

  14. Radio wave scintillations in the ionosphere

    NASA Astrophysics Data System (ADS)

    Yeh, K. C.; Liu, C.-H.

    1982-04-01

    A review is provided of the current status of the ionosphere scintillation of radio waves, taking into account both observational and theoretical points of view. Particular attention is given to aspects of transionospheric radio wave propagation and signal statistics. The characterization of ionospheric irregularities is discussed. The observational evidence is considered along with correlation functions and spectra, the optical path and the correlation of the total electron content, the optical path structure function, and frozen fields and their generalizations. Scintillation theories are examined, taking into account a statement of the problem, the phase screen theory, a theory for weak scintillation, the parabolic equation method, the probability distributions of the scintillating signals, and polarization scintillation. A description is provided of experimental results, and aspects of temporal behavior are investigated.

  15. Empirical modelling of equatorial ionospheric scintillation

    NASA Astrophysics Data System (ADS)

    Pasricha, P. K.; Reddy, B. M.

    1986-06-01

    A computer-based model of ionospheric scintillations has been developed by Fremouw (socalled the WBMOD model) to give a mean scintillation index for a given set of observing conditions. The WBMOD model incorporates some of the scintillation observations made with the DNA wideband satellite. A comparison is made between the scintillation morphology observed at an equatorial station Ooty with the one evolved with the WBMOD model. Morphological features at other stations in the equatorial region are briefly described. The WBMOD model predicts the pre-midnight maximum seen at the Indian longitudes. The seasonal pattern reproduced by the model incorporates longitudinal variability. The solar activity dependence in the model seems to be rather high. Empirical expressions giving the dependence of scintillation index on morphological parameters are obtained

  16. Extruded scintillator for the Calorimetry applications

    NASA Astrophysics Data System (ADS)

    Dyshkant, A.; Rykalin, V.; Pla-Dalmau, A.; Beznosko, D.

    2006-10-01

    An extrusion line has been installed and successfully operated at FNAL (Fermi National Accelerator Laboratory) in collaboration with NICADD (Northern Illinois Center for Accelerator and Detector Development). This new Facility will serve to further develop and improve extruded plastic scintillator. Recently progress has been made in producing co-extruded plastic scintillator, thus increasing the potential HEP applications of this Facility. The current R&D work with extruded and co-extruded plastic scintillator for a potential ALICE upgrade, the ILC calorimetry program and the MINERvA experiment show the attractiveness of the chosen strategy for future experiments and calorimetry. We extensively discuss extruded and co-extruded plastic scintillator in calorimetry in synergy with new Solid State Photomultipliers. The characteristics of extruded and co-extruded plastic scintillator will be presented here as well as results with non-traditional photo read-out.

  17. Extruded scintillator for the calorimetry applications

    SciTech Connect

    Dyshkant, A.; Rykalin, V.; Pla-Dalmau, A.; Beznosko, D.; /SUNY, Stony Brook

    2006-08-01

    An extrusion line has been installed and successfully operated at FNAL (Fermi National Accelerator Laboratory) in collaboration with NICADD (Northern Illinois Center for Accelerator and Detector Development). This new Facility will serve to further develop and improve extruded plastic scintillator. Recently progress has been made in producing co-extruded plastic scintillator, thus increasing the potential HEP applications of this Facility. The current R&D work with extruded and co-extruded plastic scintillator for a potential ALICE upgrade, the ILC calorimetry program and the MINERvA experiment show the attractiveness of the chosen strategy for future experiments and calorimetry. We extensively discuss extruded and co-extruded plastic scintillator in calorimetry in synergy with new Solid State Photomultipliers. The characteristics of extruded and co-extruded plastic scintillator will be presented here as well as results with non-traditional photo read-out.

  18. Scintillation Effects on Space Shuttle GPS Data

    NASA Technical Reports Server (NTRS)

    Goodman, John L.; Kramer, Leonard

    2001-01-01

    Irregularities in ionospheric electron density result in variation in amplitude and phase of Global Positioning System (GPS) signals, or scintillation. GPS receivers tracking scintillated signals may lose carrier phase or frequency lock in the case of phase sc intillation. Amplitude scintillation can cause "enhancement" or "fading" of GPS signals and result in loss of lock. Scintillation can occur over the equatorial and polar regions and is a function of location, time of day, season, and solar and geomagnetic activity. Mid latitude regions are affected only very rarely, resulting from highly disturbed auroral events. In the spring of 1998, due to increasing concern about scintillation of GPS signals during the upcoming solar maximum, the Space Shuttle Program began to assess the impact of scintillation on Collins Miniaturized Airborne GPS Receiver (MAGR) units that are to replace Tactical Air Control and Navigation (TACAN) units on the Space Shuttle orbiters. The Shuttle Program must determine if scintillation effects pose a threat to safety of flight and mission success or require procedural and flight rule changes. Flight controllers in Mission Control must understand scintillation effects on GPS to properly diagnose "off nominal" GPS receiver performance. GPS data from recent Space Shuttle missions indicate that the signals tracked by the Shuttle MAGR manifest scintillation. Scintillation is observed as anomalous noise in velocity measurements lasting for up to 20 minutes on Shuttle orbit passes and are not accounted for in the error budget of the MAGR accuracy parameters. These events are typically coincident with latitude and local time occurrence of previously identified equatorial spread F within about 20 degrees of the magnetic equator. The geographic and seasonal history of these events from ground-based observations and a simple theoretical model, which have potential for predicting events for operational purposes, are reviewed.

  19. Simulation of optical interstellar scintillation

    NASA Astrophysics Data System (ADS)

    Habibi, F.; Moniez, M.; Ansari, R.; Rahvar, S.

    2013-04-01

    Aims: Stars twinkle because their light propagates through the atmosphere. The same phenomenon is expected on a longer time scale when the light of remote stars crosses an interstellar turbulent molecular cloud, but it has never been observed at optical wavelengths. The aim of the study described in this paper is to fully simulate the scintillation process, starting from the molecular cloud description as a fractal object, ending with the simulations of fluctuating stellar light curves. Methods: Fast Fourier transforms are first used to simulate fractal clouds. Then, the illumination pattern resulting from the crossing of background star light through these refractive clouds is calculated from a Fresnel integral that also uses fast Fourier transform techniques. Regularisation procedure and computing limitations are discussed, along with the effect of spatial and temporal coherency (source size and wavelength passband). Results: We quantify the expected modulation index of stellar light curves as a function of the turbulence strength - characterised by the diffraction radius Rdiff - and the projected source size, introduce the timing aspects, and establish connections between the light curve observables and the refractive cloud. We extend our discussion to clouds with different structure functions from Kolmogorov-type turbulence. Conclusions: Our study confirms that current telescopes of ~4 m with fast-readout, wide-field detectors have the capability of discovering the first interstellar optical scintillation effects. We also show that this effect should be unambiguously distinguished from any other type of variability through the observation of desynchronised light curves, simultaneously measured by two distant telescopes.

  20. Development of Scintillator Detectors for Fast-Ignition Experiments and Down-Scattered Neutron Measurements on OMEGA

    NASA Astrophysics Data System (ADS)

    Glebov, V. Yu.; Stoeckl, C.; Theobald, W.; Sangster, T. C.; Marshall, K. L.; Shoup, M. J., III; Buczek, T.; Pruyne, A.; Fox, M.; Duffy, T.; Moran, M. J.; Lauck, R.

    2009-11-01

    A small signal must be recorded after very large DT or hard x-ray signals in a neutron time-of-flight detector to measure down-scattered neutrons in cryogenic DT implosions or to measure neutron yield in the presence of hard x-ray background from an ultrahigh-intensity laser. Several detectors with plastic and liquid scintillators were developed and tested at the Omega/Omega EP Laser Facility in cryogenic DT implosions and integrated fast-ignition experiments. A gated photomultiplier tube was used to eliminate large DT or hard x-ray signals. The liquid scintillator consists of 0.4% PPO, 0.04% MSB dissolved in xylene and saturated with oxygen. The afterglow (long decay constant) with this scintillator is ˜100x less than conventional scintillators. This is an essential property to mitigate the residual scintillator signal in down-scattered neutron measurements and fast-ignition experiments. Detector designs and responses with the different scintillators will be presented. This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement Nos. DE-FC52-08NA28302, DE-FC02-04ER54789, and DE-FG02-05ER54839.