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Sample records for liquid organic scintillator

  1. 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.

  2. 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.

  3. Lithium-loaded liquid scintillators

    DOEpatents

    Dai, Sheng; Kesanli, Banu; Neal, John S.

    2012-05-15

    The invention is directed to a liquid scintillating composition containing (i) one or more non-polar organic solvents; (ii) (lithium-6)-containing nanoparticles having a size of up to 10 nm and surface-capped by hydrophobic molecules; and (iii) one or more fluorophores. The invention is also directed to a liquid scintillator containing the above composition.

  4. 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.

  5. Measurement of neutron dose with an organic liquid scintillator coupled with a spectrum weight function.

    PubMed

    Kim, E; Endo, A; Yamaguchi, Y; Yoshizawa, M; Nakamura, T

    2002-01-01

    A dose evaluation method for neutrons in the energy range of a few MeV to 100 MeV has been developed using a spectrum weight function (G-function), which is applied to an organic liquid scintillator of 12.7 cm in diameter and 12.7 cm in length. The G-function that converts the pulse height spectrum of the scintillator into the ambient dose equivalent, H*(10), was calculated by an unfolding method using successive approximation of the response function of the scintillator and the ambient dose equivalent per unit neutron fluence (H*(10) conversion coefficients) of ICRP 74. To verify the response function of the scintillator and the value of H*(10) evaluated by the G-function. pulse height spectra of the scintillator were measured in some different neutron fields, which have continuous energy, monoenergetic and quasi-monoenergetic spectra. Values of H*(10) estimated using the G-function and pulse height spectra of the scintillator were compared with those calculated using neutron energy spectra. These doses agreed with each other. From the results, it was concluded that H*(10) can be evaluated directly from the pulse height spectrum of the scintillator by applying the G-function proposed in this study. PMID:12212900

  6. A comparison of collimator geometries for imaging mixed radiation fields with fast liquid organic scintillators

    SciTech Connect

    Gamage, K. A. A.; Joyce, M. J.; Taylor, G. C.

    2011-07-01

    As a result of recent advances in digital pulse-shape discrimination methods it has become possible to image mixed fields (radiation environments compromising both neutrons and gamma rays) relatively quickly with a single, organic liquid 'fast' scintillator within a heavy metal collimator. The use of a liquid scintillator has significant benefits over other techniques for imaging radiation environments as the acquired data can be analysed to provide separate information about the gamma and neutron emissions from a source (or sources) in a single scan. The imaging resolution achieved is fundamentally related to the detector efficiency and to the collimator geometry. In this paper the impact of using two different geometries of tungsten collimator are compared experimentally and three different materials considered in the Monte Carlo simulation, in order to determine the optimum set-up for mixed-field imaging. The measurements were performed in the low-scatter facility of the National Physical Laboratory, Teddington. (authors)

  7. Liquid Scintillator Purification

    SciTech Connect

    Kishimoto, Y.

    2005-09-08

    The KamLAND collaboration has studied background requirements and purification methods needed to observe the 7Be neutrino from the sun. First we will discuss the present background situation in KamLAND where it is found that the main background components are 210Pb and 85Kr. It is then described how to purify the liquid scintillator. The present status and results on how to remove 210Pb from the liquid scintillator are discussed. Specifically, the detailed analysis of the effects of distillation and adsorption techniques are presented.

  8. Development of a new neutron monitor using a boron-loaded organic liquid scintillation detector

    NASA Astrophysics Data System (ADS)

    Rasolonjatovo, A. H. D.; Shiomi, T.; Kim, E.; Nakamura, T.; Nunomiya, T.; Endo, A.; Yamaguchi, Y.; Yoshizawa, M.

    2002-10-01

    A new type of neutron dose monitor was developed by using a 12.7 cm diameter×12.7 cm long boron-loaded organic liquid scintillation detector BC523A. This detector aims to have a response in the wide energy range of thermal energy to 100 MeV by using the H and C reactions to the fast neutrons of organic liquid and the 10B(n, α) reaction to thermalized neutrons in the liquid. The response functions of this detector were determined by the Monte Carlo simulation in the energy region from thermal energy to 100 MeV. Using these response functions, the spectrum-weighted dose function, G-function, to get the neutron dose from the light output spectrum of the detector was also determined by the unfolding technique. The calculated G-function was applied to determine the neutron dose in real neutron fields having energies ranging from thermal energy to several tens of MeV, where the light output spectra were measured with the BC523A detector. The thus-obtained ambient doses and effective doses show rather good agreement with the fluence-to-dose conversion factor given by ICRP 74. This detector will be useful as a wide-energy range neutron monitor.

  9. 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.

  10. 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.

  11. Free liquid scintillation counting bibliography

    SciTech Connect

    1996-12-31

    Packard Instrument Company announces the availability of its newly updated Bibliography of Packard Tri-Carb Liquid Scintillation Analyzers. This unique new booklet lists 628 references in which Packard Tri-Carb{reg_sign} liquid scintillation analyzers have been used in life science, environmental, nuclear power and archaeological measurements. All listings are cross-referenced by radionuclide, specific field of study and author.

  12. Study on gamma response function of EJ301 organic liquid scintillator with GEANT4 and FLUKA

    NASA Astrophysics Data System (ADS)

    Zhang, Su-Ya-La-Tu; Chen, Zhi-Qiang; Han, Rui; Liu, Xing-Quan; Wada, R.; Lin, Wei-Ping; Jin, Zeng-Xue; Xi, Yin-Yin; Liu, Jian-Li; Shi, Fu-Dong

    2013-12-01

    The gamma response function is required for energy calibration of EJ301 (5 cm in diameter and 20 cm in height) organic liquid scintillator detector by means of gamma sources. The GEANT4 and FLUKA Monte Carlo simulation packages were used to simulate the response function of the detector for standard 22Na, 60Co, 137Cs gamma sources. The simulated results showed a good agreement with experimental data by incorporating the energy resolution function to simulation codes. The energy resolution and the position of the maximum Compton electron energy were obtained by comparing measured light output distribution with simulated one. The energy resolution of the detector varied from 21.2% to 12.4% for electrons in the energy region from 0.341 MeV to 1.12 MeV. The accurate position of the maximum Compton electron energy was determined at the position 81% of maximum height of Compton edges distribution. In addition, the relation of the electron energy calibration and the effective neutron detection thresholds were described in detail. The present results indicated that both packages were suited for studying the gamma response function of EJ301 detector.

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

    DOE PAGES

    Keefer, G.; Grant, C.; Piepke, A.; Ebihara, T.; Ikeda, H.; Kishimoto, Y.; Kibe, Y.; Koseki, Y.; Ogawa, M.; Shirai, J.; et al

    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.

  14. 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

  15. New Organic Scintillators for Neutron Detection

    SciTech Connect

    Iwanowska, Joanna; Szczeniak, Tomasz

    2010-01-05

    This paper present the current work on neutron detection in Soltan Institute for Nuclear Studies. Lately, we have focused our research on the development of new organic scintillators including liquid scintillators for neutron detection and associated measurements. We measured liquid scintillators (also {sup 10}B-doped for thermal neutron detection){sup 3}He tubes, composites, etc. Response of the following detectors on thermal neutrons, fast neutrons and gamma radiation - the pulse shape discrimination (PSD)- has been mainly performed by means of a zero-crossing (ZC) method.

  16. Characterization of a 6Li-loaded liquid organic scintillator for fast neutron spectrometry and thermal neutron detection.

    PubMed

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

    2013-07-01

    The characterization of a liquid scintillator incorporating an aqueous solution of enriched lithium chloride to produce a scintillator with 0.40% (6)Li is presented, including the performance of the scintillator in terms of its optical properties and neutron response. The scintillator was incorporated into a fast neutron spectrometer, and the light output spectra from 2.5 MeV, 14.1 MeV, and (252)Cf neutrons were measured using capture-gated coincidence techniques. The spectrometer was operated without coincidence to perform thermal neutron measurements. Possible improvements in spectrometer performance are discussed.

  17. Development of neutron-monitor detector using liquid organic scintillator coupled with 6Li + ZnS(Ag) Sheet.

    PubMed

    Sato, Tatsuhiko; Endo, Akira; Yamaguchi, Yasuhiro; Takahashi, Fumiaki

    2004-01-01

    A phoswitch-type detector has been developed for monitoring neutron doses in high-energy accelerator facilities. The detector is composed of a liquid organic scintillator (BC501A) coupled with ZnS(Ag) sheets doped with 6Li. The dose from neutrons with energies above 1 MeV is evaluated from the light output spectrum of the BC501A by applying the G-function, which relates the spectrum to the neutron dose directly. The dose from lower energy neutrons, on the other hand, is estimated from the number of scintillations emitted from the ZnS(Ag) sheets. Characteristics of the phoswitch-type detector were studied experimentally in some neutron fields. It was found from the experiments that the detector has an excellent property of pulse-shape discrimination between the scintillations of BC501A and the ZnS(Ag) sheets. The experimental results also indicate that the detector is capable of reproducing doses from thermal neutrons as well as neutrons with energies from one to several tens of megaelectronvolts (MeV).

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  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. Mixed crystal organic scintillators

    DOEpatents

    Zaitseva, Natalia P; Carman, M Leslie; Glenn, Andrew M; Hamel, Sebastien; Hatarik, Robert; Payne, Stephen A; Stoeffl, Wolfgang

    2014-09-16

    A mixed organic crystal according to one embodiment includes a single mixed crystal having two compounds with different bandgap energies, the organic crystal having a physical property of exhibiting a signal response signature for neutrons from a radioactive source, wherein the signal response signature does not include a significantly-delayed luminescence characteristic of neutrons interacting with the organic crystal relative to a luminescence characteristic of gamma rays interacting with the organic crystal. According to one embodiment, an organic crystal includes bibenzyl and stilbene or a stilbene derivative, the organic crystal having a physical property of exhibiting a signal response signature for neutrons from a radioactive source.

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

    DOE PAGES

    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 % 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

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.; Bellefon, A. De; Kerret, H. De; 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.; Feilitzsch, F. Von; 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.

  14. 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.

  15. 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.

  16. Light yield and energy transfer in a new Gd-loaded liquid scintillator

    NASA Astrophysics Data System (ADS)

    Aberle, C.; Buck, C.; Hartmann, F. X.; Schönert, S.

    2011-11-01

    We investigate a new gadolinium-loaded organic liquid scintillator which is designed to detect electron antineutrinos. A model has been developed to account for the various energy transfer paths possible in a liquid scintillator with multiple solvents, one fluor and a quenching component. Experimental light yield measurements were carried out to determine the relative rates for the energy transfers included in the model. Model predictions were used to tune the luminescent properties of the Gd-loaded target scintillator and the unloaded Gamma Catcher scintillator for the reactor neutrino experiment Double Chooz.

  17. 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.

  18. 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.

  19. 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.

  20. Liquid Scintillator Production for the NOvA Experiment

    SciTech Connect

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

    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.

  1. 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.

  2. 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.

  3. 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. PMID:16604622

  4. A fine grained electromagnetic lead-liquid scintillator calorimeter

    NASA Astrophysics Data System (ADS)

    Bachman, L.; Bonesini, M.; Cavalli, D.; Costa, G.; Fischer, J.; Fluri, L.; Kienzle-Focacci, M. N.; Mandelli, L.; Martin, M.; Mazzanti, M.; Mermod, R.; Pensotti-Rancoita, S.; Perrin, D.; Rosselet, L.; Rutschmann, J.; Tamborini, M.; Vuilleumier, J. M.; Werlen, M.

    1983-02-01

    A new technique using liquid scintillator contained in teflon tubes to build a low cost high spatial resolution electromagnetic sampling calorimeter is described. Test results and comparison with a Monte Carlo simulation are presented.

  5. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

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

  7. Response of liquid scintillator assemblies as a function of angular orientation

    NASA Astrophysics Data System (ADS)

    Naeem, S. F.; Scarpelli, M.; Miller, E.; Clarke, S. D.; Pozzi, S. A.

    2014-06-01

    Liquid scintillator detector assemblies contain an inert nitrogen expansion volume to allow for expansion of the liquid with changing temperature. Measurements and Geant4 Monte Carlo simulations are performed to study the dependence of pulse height distribution shapes as a function of detector angle for two liquid scintillators assemblies filled with 97% organic-liquid cocktail and a 3% expansion volume. A 12.7-cm diameter by 12.7-cm long and a 7.6-cm diameter by 9.1-cm long EJ-309 liquid scintillator assemblies are investigated using a 137Cs gamma-ray source. Aside from the differences in dimensions, the detector assemblies also differed in the design of the active detector volume: there is no light guide in the 12.7-cm-diameter detector assembly, whereas the 7.6-cm-diameter detector contains a BK7 light guide between the scintillation liquid and optical coupling to the photomultiplier tube. Results for the 12.7-cm-diameter detector show a decrease in the position of the Compton edge ranges from 4% to 40% at detector orientations where the expansion volume exists between scintillating medium and the photomultiplier tube. Results for the 7.6-cm-diameter detector show that the position of the Compton edge is relatively unaffected at all detector orientations due to the presence of light guide.

  8. Gasolines as primary solvents in liquid scintillation counting

    SciTech Connect

    Fernandez, A.; Ma Pinto, R.; Sillero, A.

    1986-11-01

    Gasolines from several commercial sources have been used as primary solvents in liquid scintillation counting of dry and aqueous samples of either /sup 3/H- or /sup 14/C-labeled compounds. Dry samples can be counted only by the addition of fluors to the gasolines, and compared to a standard liquid scintillator, efficiencies of around 75% were attained. For the counting of aqueous samples, gasolines must also be supplemented with secondary solvents (i.e., 10% naphthalene, 5% Triton X-100, or 10% methanol). Simply with Triton X-100, efficiencies similar to those obtained with a dioxane-based liquid scintillator were observed in the case of some gasolines. Drawbacks to gasoline are the higher toxicity and the variation of efficiency, probably depending on the presence of color markers. On the positive side is the low price of the gasolines, compared with either toluene or dioxane, and the facility of purchasing.

  9. Carbon-14 Dating with the Liquid Scintillation Counter: Total Synthesis of the Benzene Solvent.

    PubMed

    Tamers, M A

    1960-09-01

    Samples are analyzed for natural radiocarbon content by a total synthesis of benzene from their organic constituents. The benzene is employed as the solvent in a liquid scintillation counter. The instrument used permits 15grams of carbon to be counted with an efficiency of 40 percent and a background of 13 counts per minute.

  10. Melt-cast organic glasses as high-efficiency fast neutron scintillators

    NASA Astrophysics Data System (ADS)

    Carlson, Joseph S.; Feng, Patrick L.

    2016-10-01

    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. 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.

  11. 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

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. Development of lithium-loaded liquid scintillator for PROSPECT

    NASA Astrophysics Data System (ADS)

    Norcini, Danielle; Prospect Collaboration

    2015-04-01

    The PROSPECT experiment will use a segmented detector positioned 7-20m from the High Flux Isotope Reactor core to measure the antineutrino spectrum of uranium-235 and perform a sterile neutrino search. Such measurements require the use of liquid scintillator with the capability to distinguish prompt and delayed signals from inverse beta decay events. The characterization of light yield, pulse shape discrimination performance, and neutron capture properties of the lithium-loaded scintillator have been studied with a test detector at Yale. These results will be discussed in the context of their application to antineutrino detection with the PROSPECT experiment. on behalf of the PROSPECT collaboration.

  17. 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

  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. Measuring the 14C content in liquid scintillators

    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.; Słupecki, M.; Trzaska, W. H.; Umerov, Sh I.; Veresnikova, A. V.; Virkajärvi, A.; Yanovich, Y. A.; Zavarzina, V. P.

    2016-05-01

    We are going to perform a series of measurements where the 14C/12 C ratio will be measured from several liquid scintillator samples with a dedicated setup. The setup is designed with the aim of measuring ratios smaller than 10-18. Measurements take place in two underground laboratories: in the Baksan Neutrino Observatory, Russia and in the Pyhäsalmi mine, Finland. In Baksan the measurements started in 2015 and in Pyhäsalmi they start in the beginning of 2015. In order to fully understand the operation of the setup and its background contributions a development of simulation packages has also been started. Low-energy neutrino detection with a liquid scintillator requires that the intrinsic 14C content in the liquid is extremely low. In the Borexino CTF detector at Gran Sasso, Italy the 14C/12C ratio of 2 × 10-18 has been achieved being the lowest 14C concentration ever measured. In principle, the older the oil or gas source that the liquid scintillator is derived of and the deeper it situates, the smaller the 14C/12C ratio is supposed to be. This, however, is not generally the case, and the ratio is probably determined by the U and Th content of the local environment.

  20. 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

  1. A Novel Particle Detector: Quantum Dot Doped Liquid Scintillator

    NASA Astrophysics Data System (ADS)

    Winslow, Lindley; Conrad, Janet; Jerry, Ruel

    2010-02-01

    Quantum dots are semiconducting nanocrystals. When excited by light shorter then their characteristic wavelength, they re-emit in a narrow band around this wavelength. The size of the quantum is proportional to the characteristic wavelength so they can be tuned for many applications. CdS quantum dots are made in wavelengths from 360nm to 460nm, a perfect range for the sensitivity of photo-multiplier tubes. The synthesis of quantum dots automatically leaves them in toluene, a good organic scintillator and Cd is a particularly interesting material as it has one of the highest thermal neutron cross sections and has several neutrinoless double beta decay and double electron capture isotopes. The performance of quantum dot loaded scintillator compared to standard scintillators is measured and some unique properties presented. )

  2. The next-generation liquid-scintillator neutrino observatory LENA

    NASA Astrophysics Data System (ADS)

    Wurm, Michael; Beacom, John F.; Bezrukov, Leonid B.; Bick, Daniel; Blümer, Johannes; Choubey, Sandhya; Ciemniak, Christian; D'Angelo, Davide; Dasgupta, Basudeb; Derbin, Alexander; Dighe, Amol; Domogatsky, Grigorij; Dye, Steve; Eliseev, Sergey; Enqvist, Timo; Erykalov, Alexey; von Feilitzsch, Franz; Fiorentini, Gianni; Fischer, Tobias; Göger-Neff, Marianne; Grabmayr, Peter; Hagner, Caren; Hellgartner, Dominikus; Hissa, Johannes; Horiuchi, Shunsaku; Janka, Hans-Thomas; Jaupart, Claude; Jochum, Josef; Kalliokoski, Tuomo; Kayunov, Alexei; Kuusiniemi, Pasi; Lachenmaier, Tobias; Lazanu, Ionel; Learned, John G.; Lewke, Timo; Lombardi, Paolo; Lorenz, Sebastian; Lubsandorzhiev, Bayarto; Ludhova, Livia; Loo, Kai; Maalampi, Jukka; Mantovani, Fabio; Marafini, Michela; Maricic, Jelena; Marrodán Undagoitia, Teresa; McDonough, William F.; Miramonti, Lino; Mirizzi, Alessandro; Meindl, Quirin; Mena, Olga; Möllenberg, Randolph; Muratova, Valentina; Nahnhauer, Rolf; Nesterenko, Dmitry; Novikov, Yuri N.; Nuijten, Guido; Oberauer, Lothar; Pakvasa, Sandip; Palomares-Ruiz, Sergio; Pallavicini, Marco; Pascoli, Silvia; Patzak, Thomas; Peltoniemi, Juha; Potzel, Walter; Räihä, Tomi; Raffelt, Georg G.; Ranucci, Gioacchino; Razzaque, Soebur; Rummukainen, Kari; Sarkamo, Juho; Sinev, Valerij; Spiering, Christian; Stahl, Achim; Thorne, Felicitas; Tippmann, Marc; Tonazzo, Alessandra; Trzaska, Wladyslaw H.; Vergados, John D.; Wiebusch, Christopher; Winter, Jürgen

    2012-06-01

    As part of the European LAGUNA design study on a next-generation neutrino detector, we propose the liquid-scintillator detector LENA (Low Energy Neutrino Astronomy) as a multipurpose neutrino observatory. The outstanding successes of the Borexino and KamLAND experiments demonstrate the large potential of liquid-scintillator detectors in low-energy neutrino physics. Low energy threshold, good energy resolution and efficient background discrimination are inherent to the liquid-scintillator technique. A target mass of 50 kt will offer a substantial increase in detection sensitivity. At low energies, the variety of detection channels available in liquid scintillator will allow for an energy - and flavor-resolved analysis of the neutrino burst emitted by a galactic Supernova. Due to target mass and background conditions, LENA will also be sensitive to the faint signal of the Diffuse Supernova Neutrino Background. Solar metallicity, time-variation in the solar neutrino flux and deviations from MSW-LMA survival probabilities can be investigated based on unprecedented statistics. Low background conditions allow to search for dark matter by observing rare annihilation neutrinos. The large number of events expected for geoneutrinos will give valuable information on the abundances of Uranium and Thorium and their relative ratio in the Earth's crust and mantle. Reactor neutrinos enable a high-precision measurement of solar mixing parameters. A strong radioactive or pion decay-at-rest neutrino source can be placed close to the detector to investigate neutrino oscillations for short distances and sub-MeV to MeV energies. At high energies, LENA will provide a new lifetime limit for the SUSY-favored proton decay mode into kaon and antineutrino, surpassing current experimental limits by about one order of magnitude. Recent studies have demonstrated that a reconstruction of momentum and energy of GeV particles is well feasible in liquid scintillator. Monte Carlo studies on the

  3. New Efficient Organic Scintillators Derived from Pyrazoline.

    PubMed

    Bliznyuk, Valery N; Seliman, Ayman F; Ishchenko, Alexander A; Derevyanko, Nadezhda A; DeVol, Timothy A

    2016-05-25

    We report on the synthesis, spectroscopic and scintillation properties of three new pyrazoline core based fluorophores. Fluorescence properties of the fluorophores have been studied both in a solution state and in a solid polyvinyltoluene (PVT) resin matrix of different porosity. The synthesized fluorophores were found to be promising candidates for application in plastic scintillators for detection of ionizing radiation (alpha, beta particles, γ rays and neutrons) and demonstrated superior efficiency in comparison to the existing commercially used fluorophores (2-(1-naphthyl)-5-phenyloxazole (αNPO), 9,10-diphenylanthracene, etc.). Moreover, the suggested synthetic route allows functionalization of the fluorophores with a vinyl group for further covalent bound to the PVT or other vinyl polymer matrices, which dramatically improves chemical stability of the system simultaneously improving the photoluminescence quantum yield. Possible mechanisms of the enhanced scintillation properties are discussed based on preliminary quantum mechanical calculations and spectroscopic characteristics of the fluorophores under study. PMID:27163887

  4. Optical design considerations for efficient light collection from liquid scintillation counters.

    PubMed

    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

    2015-03-20

    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. 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 present in the laboratory and within the instrument's 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 (LSC) 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 LSC system. PMID:25968530

  5. Simulation results of liquid and plastic scintillator detectors for reactor antineutrino detection - A comparison

    NASA Astrophysics Data System (ADS)

    Kashyap, V. K. S.; Pant, L. M.; Mohanty, A. K.; Datar, V. M.

    2016-03-01

    A simulation study of two kinds of scintillation detectors has been done using GEANT4. We compare plastic scintillator and liquid scintillator based designs for detecting electron antineutrinos emitted from the core of reactors. The motivation for this study is to set up an experiment at the research reactor facility at BARC for very short baseline neutrino oscillation study and remote reactor monitoring.

  6. 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.

  7. 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. PMID:27406840

  8. 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.

  9. A 222Rn source for low-background liquid scintillation detectors

    NASA Astrophysics Data System (ADS)

    Johnson, Michael; Benziger, Jay; Stoia, Catherine; Calaprice, Frank; Chen, Mark; Darnton, Nicholas; Loeser, Fred; Bruce Vogelaar, R.

    A technique for producing a radioactive source suitable for use in a low-background liquid scintillation detector is described. 222Rn was concentrated from air to prepare liquid scintillator sources spiked with 10 6 Bq/m 3 of the radioisotope. Air was stripped of CO 2 and water vapor, and passed over cooled charcoal which trapped the radon. The accumulated radon was desorbed and transferred into a pseudocumene-based scintillator. These sources have been used for position calibration in the Counting Test Facility (a 5 m 3 spherical liquid scintillation detector) at the Laboratori Nazionali del Gran Sasso.

  10. 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.

  11. ARAPUCA a new device for liquid argon scintillation light detection

    NASA Astrophysics Data System (ADS)

    Machado, A. A.; Segreto, E.

    2016-02-01

    We present a totally innovative device for the detection of liquid argon scintillation light, that has been named ARAPUCA (Argon R&D Advanced Program at UniCAmp). It is composed of a passive light collector and of active devices. The latters are standard SiPMs that operate at liquid argon temperature, while the passive collector is based on a new technology, never explored in this field before. It is a photon trap, that allows to collect light with extremely high efficiency. The total detection efficiency of the device can be tuned by modifying the ratio between the area of the active devices (SiPM) and the area of the optical window. For example, it will allow to reach a detection efficiency at the level of 1% on a surface of 50 × 50 cm2 with an active coverage of 2 × 2 cm2 (two/three large area SiPM). It is also a cheap device, since the major part of its cost is represented by the active devices. For these reason this appears to be the ideal device for scintillation light detection in large Time Projection Chambers. With appropriate modifications it can be used also in next generation Dark Matter detectors.

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

    NASA Astrophysics Data System (ADS)

    Whittington, D.; 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 composite model. Both models find τT = 1.52 μs for the decay time constant of the Ar2* 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 β-decay experiments, which suggests this parameter provides a robust metric for discriminating electrons and muons from more heavily ionizing particles.

  13. 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.

  14. Neutron imaging using the anisotropic response of crystalline organic scintillators.

    SciTech Connect

    Brubaker, Erik; Steele, John T.

    2010-11-01

    An anisotropy in a scintillator's response to neutron elastic scattering interactions can in principle be used to gather directional information about a neutron source using interactions in a single detector. In crystalline organic scintillators, such as anthracene, both the amplitude and the time structure of the scintillation light pulse vary with the direction of the proton recoil with respect to the crystalline axes. Therefore, we have investigated the exploitation of this effect to enable compact, high-efficiency fast neutron detectors that have directional sensitivity via a precise measurement of the pulse shape. We report measurements of the pulse height and shape dependence on proton recoil angle in anthracene, stilbene, p-terphenyl, diphenyl anthracene (DPA), and tetraphenyl butadiene (TPB). Image reconstruction for simulated neutron sources is demonstrated using maximum likelihood methods for optimal directional sensitivity.

  15. 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.

  16. 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.

  17. Showering cosmogenic muons in a large liquid scintillator

    NASA Astrophysics Data System (ADS)

    Grassi, Marco; Evslin, Jarah; Ciuffoli, Emilio; Zhang, Xinmin

    2014-09-01

    We present the results of FLUKA simulations of the propagation of cosmogenic muons in a 20 kton spherical liquid scintillator detector underneath 700 to 900 meters of rock. A showering muon is one which deposits at least 3 GeV in the detector in addition to ionization energy. We find that 20 percent of muons are showering and a further 11 percent of muon events are muon bundles, of which more than one muon enters the detector. In this range the showering and bundle fractions are robust against changes in the depth and topography, thus the total shower and bundle rate for a given experiment can be obtained by combining our results with an estimate for the total muon flux. One consequence is that a straightforward adaptation of the full detector showering muon cuts used by KamLAND to JUNO or RENO 50 would yield a nearly vanishing detector efficiency.

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

    DOE PAGES

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

    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.

  19. 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.

  20. 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

  1. Organic scintillator detector response simulations with DRiFT

    NASA Astrophysics Data System (ADS)

    Andrews, M. T.; Bates, C. R.; McKigney, E. A.; Solomon, C. J.; Sood, A.

    2016-09-01

    This work presents the organic scintillation simulation capabilities of DRiFT, a post-processing Detector Response Function Toolkit for MCNP® output. DRiFT is used to create realistic scintillation detector response functions to incident neutron and gamma mixed-field radiation. As a post-processing tool, DRiFT leverages the extensively validated radiation transport capabilities of MCNP® 6 , which also provides the ability to simulate complex sources and geometries. DRiFT is designed to be flexible, it allows the user to specify scintillator material, PMT type, applied PMT voltage, and quenching data used in simulations. The toolkit's capabilities, which include the generation of pulse shape discrimination plots and full-energy detector spectra, are demonstrated in a comparison of measured and simulated neutron contributions from 252Cf and PuBe, and photon spectra from 22Na and 228Th sources. DRiFT reproduced energy resolution effects observed in EJ-301 measurements through the inclusion of scintillation yield variances, photon transport noise, and PMT photocathode and multiplication noise.

  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. Partitioning of krypton-85 in liquid scintillation cocktail

    SciTech Connect

    Hohorst, F.A.; Sherlock, M.A.

    1994-12-01

    Krypton is one of the noble gases. As such, it forms compounds only with exceptionally strong oxidizing agents. The concentration of krypton in air is 1.139 parts per million by volume. In general, its behavior is best described as that of an ideal gas. Krypton-85 is the longest lived of the common radioactive noble gases with a half life of 10.72 years. Gamma radiation at 513.990 keV has an intensity of only 0.434%. Most decay is {beta}{sup -} emission with a maximum energy of 687.0 keV and an average energy of 251.4 keV. The analytical chemistry of krypton-85 is driven by these factors. High concentrations may be gamma counted directly. Low levels are typically determined by more sensitive techniques such as liquid scintillation counting (LSC) where detection limits on the order of 1 picocurie (pCi) are routinely achieved. For a 5 standard cubic centimeter (scc) sample, this represents a concentration of 0.2 pCi/scc, well below the DOE Air Immersion Derived Concentration Guideline (G) of 3 pCi/scc. As a gas, krypton in a sealed LSC vial distributes itself between the liquid phase and the gas phase. Some past work has used gamma counting at levels many orders of magnitude greater than those now achievable by LSC to study the distribution of krypton. This effect is of interest in the analytical chemistry of krypton-85 because geometrical considerations influence how much of the material in the gas phase decays generating particles which then impact the liquid phase where they may be counted.

  4. Liquid Scintillation Radioassay in Disposable Microcentrifuge Tubes: Radioimmune Precipitates and Other Applications

    PubMed Central

    Schaffer, F. L.; Soergel, M. E.

    1974-01-01

    A simple, economical radioassay system employing disposable polypropylene microcentrifuge tubes was developed. Plastic adapters permitted automatic operation in liquid scintillation spectrometers. Counting efficiencies of 3H, 14C, 32P, and 125I in liquid scintillation cocktails and of 32P by Cerenkov radiation (at lower efficiency in absence of added scintillator) were comparable to those in standard vials. Multipurpose use of the microtubes made the system versatile and expedient, e.g., collection of precipitates and radioassay in the same container. Collection of radioimmune precipitates was aided by a carrier inorganic precipitate, Mg2P2O7. Images PMID:4137041

  5. Organic scintillation detector response simulation using non-analog MCNPX-PoliMi

    SciTech Connect

    Prasad, S.; Clarke, S. D.; Pozzi, S. A.; Larsen, E. W.

    2012-07-01

    Organic liquid scintillation detectors are valuable for the detection of special nuclear material since they are capable of detecting both neutrons and gamma rays. Scintillators can also provide energy information which is helpful in identification and characterization of the source. In order to design scintillation based measurement systems appropriate simulation tools are needed. MCNPX-PoliMi is capable of simulating scintillation detector response; however, simulations have traditionally been run in analog mode which leads to long computation times. In this paper, non-analog MCNPX-PoliMi mode which uses variance reduction techniques is applied and tested. The non-analog MCNPX-PoliMi simulation test cases use source biasing, geometry splitting and a combination of both variance reduction techniques to efficiently simulate pulse height distribution and then time-of-flight for a heavily shielded case with a {sup 252}Cf source. An improvement factor (I), is calculated for distributions in each of the three cases above to analyze the effectiveness of the non-analog MCNPX-PoliMi simulations in reducing computation time. It is found that of the three cases, the last case which uses a combination of source biasing and geometry splitting shows the most improvement in simulation run time for the same desired variance. For pulse height distributions speedup ranging from a factor 5 to 25 is observed, while for time-of-flights the speedup factors range from 3 to 10. (authors)

  6. Standardization of radium-223 by liquid scintillation counting.

    PubMed

    Cessna, J T; Zimmerman, B E

    2010-01-01

    Liquid scintillation (LS) counting was undertaken as part of the primary standardization of (223)Ra. Radium-223 decays with a half life of 11.43 d through a chain of shorter-lived daughter radionuclides, resulting in five alpha decays and three beta decays. The CIEMAT/NIST method of tritium efficiency tracing was employed, with the beta efficiencies being calculated using the program CN2004, developed by the Physikalisch-Technische Bundesanstalt (PTB). The total calculated LS efficiency, considering all daughter radionuclides, was approximately 598%. Separate experiments were performed to rule out loss of the 3.96 s (219)Ra daughter from the cocktail and possible counting loss of the 1.78 ms (215)Po daughter due to LS counter dead-time. No loss was observed in either experiment. In the final experiment an expanded uncertainty (k=2) of 0.55% was achieved. Results were in excellent agreement with confirmatory measurements performed by 2pialpha proportional counting. However, results are not in agreement with methods based on gamma ray measurements.

  7. 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.

  8. Method for measuring multiple scattering corrections between liquid scintillators

    DOE PAGES

    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.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. A Highly Efficient Neutron Veto Using Boron-Loaded Liquid Scintillator

    SciTech Connect

    Wright, A.; Mosteiro, P.; Loer, B.; Calaprice, F.

    2011-04-27

    By surrounding a dark matter detector with a layer of boron-loaded liquid scintillator, a highly efficient neutron veto can be produced. In Monte Carlo studies, a one meter thick layer of scintillator has a veto efficiency greater than 99.5% for nuclear recoil events induced by radiogenic neutrons, and a veto efficiency of more than 95% for nuclear recoil events produced by cosmogenic neutrons. The use of boron-loaded scintillator both reduces the veto-induced dead time by decreasing the neutron capture time and allows high neutron detection efficiency to be achieved in a relatively compact geometry.

  14. Passive Measurement of Organic-Scintillator Neutron Signatures for Nuclear Safeguards Applications

    SciTech Connect

    Jennfier L. Dolan; Eric C. Miller; Alexis C. Kaplan; Andreas Enqvist; Marek Flaska; Alice Tomanin; Paolo Peerani; David L. Chichester; Sara A. Pozzi

    2012-10-01

    At nuclear facilities, domestically and internationally, most measurement systems used for nuclear materials’ control and accountability rely on He-3 detectors. Due to resource shortages, alternatives to He-3 systems are needed. This paper presents preliminary simulation and experimental efforts to develop a fast-neutron-multiplicity counter based on liquid organic scintillators. This mission also provides the opportunity to broaden the capabilities of such safeguards measurement systems to improve current neutron-multiplicity techniques and expand the scope to encompass advanced nuclear fuels.

  15. Energy transfer and light yield properties of a new highly loaded indium(III) β-diketonate organic scintillator system

    NASA Astrophysics Data System (ADS)

    Buck, C.; Hartmann, F. X.; Motta, D.; Schoenert, S.

    2007-02-01

    We present combined experimental and model studies of the light yield and energy transfer properties of a newly developed high light yield scintillator based on indium(III)-tris(2,4-pentanedionate) in a 2-(4-biphenyl)-5-phenyloxazole (BPO), methoxybenzene organic liquid; of interest to the detection of solar electron neutrino oscillations. Optical measurements are made to understand the energy transfer properties and a model is advanced to treat the unusual conditions of high metal and fluor loadings. Such scintillator types are of interest to the exploration of novel luminescent materials and the development of large-scale detectors for studying fundamental properties of naturally occurring neutrinos.

  16. 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. PMID:26334781

  17. A study of the scintillation light induced in liquid xenon by electrons and alpha particles

    NASA Technical Reports Server (NTRS)

    Aprile, Elena; Mukherjee, Reshmi; Suzuki, Masayo

    1990-01-01

    The time dependence and the intensity of the primary scintillation light in liquid Xe excited by Am-241 alpha particles and Bi-207 internal-conversion electrons were measured at different electric-field strengths. High-purity liquid Xe was used to fill a parallel-plate ionization chamber equipped with a CaF2 window coupled to a UV-sensitive photomultiplier tube. The effect of the specific ionization density on the scintillation light and the time correlation between the light signal and the charge signal is reported. It is demonstrated that the fast scintillation signal produced in liquid Xe by an ionizing particle provides an ideal trigger in a detector aiming at a complete three-dimensional event reconstruction with an excellent background rejection capability.

  18. Experimental determination of elemental compositions and densities of several common liquid scintillators.

    PubMed

    Rodríguez-Barquero, Leonor; Los Arcos, José M

    2010-01-01

    New accurate data for the density and the elemental composition of several common liquid scintillators have been determined in this work. These data can be used to correctly determine or calculate the counting efficiency of radio-nuclides as well as to evaluate more accurately the uncertainties in LSC measurements due to variability on the composition of scintillators. The discrepancy between nominal densities at 20 degrees C and the real densities at 20 degrees C or 16 degrees C can reach up to 4% among different batches of commercial scintillators all having the same nominal composition. Also significant differences in the elemental composition of commercial cocktails have been found compared to the nominal values. These differences range from 2% up to 260% depending on the element and the scintillator being measured. PMID:20106669

  19. Spatial response characterization of liquid scintillator detectors using collimated gamma-ray and neutron beams

    NASA Astrophysics Data System (ADS)

    Naeem, S. F.; Clarke, S. D.; Pozzi, S. A.

    2013-10-01

    Liquid scintillators are suitable for many applications because they can detect and characterize fast neutrons as well as gamma-rays. This paper presents the response of a 15-cm-in-length×15-cm-in-height×8.2-cm-in-width EJ-309 liquid scintillator with respect to the position of neutron and gamma-ray interactions. Liquid scintillator cells are typically filled with 97% of the scintillating cocktail to address thermal expansion of the liquid in varying temperature conditions. Measurements were taken with collimated 137Cs and 252Cf sources for gamma-ray and neutron mapping of the detector, respectively. MCNPX-PoliMi (ver. 2.0) simulations were also performed to demonstrate the spatial response of the detector. Results show that the detector response is greatest at the center and decreases when the collimated neutron and gamma-ray beam is moved toward the edge of the detector. The measured response in the voxels surrounding the detector center decreased by approximately 6% and 12% for gamma-ray and neutron scans, respectively, when compared to the center voxel. The measured decrease in the detector response was most pronounced at the corners of detector assembly. For the corner voxels located in the bottom row of the detector, the measured response decreased by approximately 39% for both gamma-ray and neutron scans. For the corner voxels located in the top row of the detector, the measured response decreased by approximately 66% and 48% for gamma-ray and neutron scans, respectively. Both measurements and simulations show the inefficient production of secondary charged particles in the voxels located in the top portion of the detector due to the presence of expansion volume. Furthermore, the presence of the expansion volume potentially affects the transport of the scintillation light through the coupling window between the liquid scintillator and the photocathode in the photomultiplier tube.

  20. 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.

  1. Effect of quench on alpha/beta pulse shape discrimination of liquid scintillation cocktails.

    PubMed

    DeVol, Timothy A; Theisen, Christopher D; DiPrete, David P

    2007-05-01

    The objectives of this paper are (1) to illustrate that knowledge of the external quench parameter is insufficient to properly setup a pulse shape discriminating liquid scintillation counter (LSC) for quantitative measurement, (2) to illustrate dependence on pulse shape discrimination on the radionuclide (more than just radiation and energy), and (3) to compare the pulse shape discrimination (PSD) of two commercial instruments. The effects various quenching agents, liquid scintillation cocktails, radionuclides, and LSCs have on alpha/beta pulse shape discriminating liquid scintillation counting were quantified. Alpha emitting radionuclides (239)Pu and (241)Am and beta emitter (90)Sr/(90)Y were investigated to quantify the nuclide dependence on alpha/beta pulse shape discrimination. Also, chemical and color quenching agents, nitromethane, nitric acid, and yellow dye impact on alpha/beta pulse shape discrimination using PerkinElmer Optiphase "HiSafe" 2 and 3, and Ultima Gold AB liquid scintillation cocktails were determined. The prepared samples were counted on the PerkinElmer Wallac WinSpectral 1414 alpha/beta pulse shape discriminating LSC. It was found that for the same level of quench, as measured by the external quench parameter, different quench agents influenced the pulse shape discrimination and the pulse shape discrimination parameters differently. The radionuclide also affects alpha/beta pulse shape discrimination. By comparison with the PerkinElmer Tri-carb 3150 TR/AB, the Wallac 1414 exhibited better pulse shape discrimination capability under the same experimental conditions. PMID:17440321

  2. A lead-liquid scintillator electromagnetic calorimeter for direct photon physics

    NASA Astrophysics Data System (ADS)

    Bonesini, M.; Bonvin, E.; Booth, P. S. L.; Bortoletto, D.; Carroll, L. J.; Cass, A. J.; Cavalli, D.; Cecchet, G.; Costa, G.; Donnat, M.; Dorsaz, P. A.; Edwards, D. N.; Fischer, J. R.; Fluri, L.; Frame, D.; Gianotti, F.; Jack, S.; Jackson, J. N.; Kelly, M.; Kienzle-Focacci, M. N.; Lucock, R.; Lynch, J. G.; Mandelli, L.; Martin, M.; Mathys, L.; Maxwell, A.; Mazzanti, M.; Myerscough, J. J.; Negus, P. J.; Pensotti-Rancoita, S.; Perini, L.; Perrin, D.; Perrin, E.; Range, W. H.; Rosselet, L.; Rutschmann, J.; Snow, S. W.; Tamborini, M.; Thompson, A. S.; Turnbull, R. M.; Wells, J.; Werlen, M.

    1987-11-01

    A fine-grained sampling electromagnetic calorimeter using liquid scintillator contained in teflon tubes, its associated electronics and reconstruction programs, as used in an experiment on direct photons at CERN, are described. The performance of the system based on three years of operation is discussed.

  3. Metal-organic scintillator crystals for X-ray, gamma ray, and neutron detection

    DOEpatents

    Boatner, Lynn A; Kolopus, James A.; Neal, John S; Ramey, Joanne Oxendine; Wisniewski, Dariusz J

    2012-01-03

    New metal-organic materials are useful as scintillators and have the chemical formula LX.sub.3(CH.sub.3OH).sub.4 where L is Y, Sc, or a lanthanide element, and X is a halogen element. An example of the scintillator materials is CeCl.sub.3(CH.sub.3OH).sub.4.

  4. 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.

  5. Development of InP solid state detector and liquid scintillator containing metal complex for measurement of pp/7Be solar neutrinos and neutrinoless double beta decay

    NASA Astrophysics Data System (ADS)

    Fukuda, Yoshiyuki; Moriyama, Shigetaka

    2012-07-01

    A large volume solid state detector using a semi-insulating Indium Phosphide (InP) wafer have been developed for measurement of pp/7Be solar neutrinos. Basic performance such as the charge collection efficiency and the energy resolution were measured by 60% and 20%, respectively. In order to detect two gammas (115keV and 497keV) from neutrino capture, we have designed hybrid detector which consist InP detector and liquid xenon scintillator for IPNOS experiment. New InP detector with thin electrode (Cr 50Å- Au 50Å). For another possibility, an organic liquid scintillator containing indium complex and zirconium complex were studied for a measurement of low energy solar neutrinos and neutrinosless double beta decay, respectively. Benzonitrile was chosen as a solvent because of good solubility for the quinolinolato complexes (2 wt%) and of good light yield for the scintillation induced by gamma-ray irradiation. The photo-luminescence emission spectra of InQ3 and ZrQ4 in benzonitrile was measured and liquid scintillator cocktail using InQ3 and ZrQ4 (50mg) in benzonitrile solutions (20 mL) with secondary scintillators with PPO (100mg) and POPOP (10mg) was made. The energy spectra of incident gammas were measured, and they are first results of the gamma-ray energy spectra using luminescent of metal complexes.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Advances in Neutron Spectroscopy with Deuterated Organic Scintillators

    NASA Astrophysics Data System (ADS)

    Febbraro, Michael; Pain, Steve; Becchetti, Frederick

    2015-10-01

    Deuterated organic scintillators have shown promise as neutron detectors for nuclear science as well as applications in nuclear non-proliferation and safeguards. In particular, they can extract neutron spectra without the use of neutron time-of-flight measurement (n-ToF) utilizing spectrum unfolding techniques. This permits the measure of cross sections of bound and unbound states with high efficiency and angular coverage. In the case of measurements with radioactive ion beams where low beam intensities limit long path n-ToF, short path n-ToF can be used to discriminate neutrons of interest from room return and background neutrons. This presentation will provide recent advances with these types of detectors. Digital pulse-shape discrimination using fast waveform digitizers, spectrum unfolding methods for extraction of neutron spectra, and a new safer deuterated-xylene formulation EJ-301D will be discussed. In addition, experimental results from measurements of discrete and continuous neutron spectra which illustrate the advantage of these detectors for certain applications in nuclear physics research and nuclear security will be shown. This work is supported by NSF and DOE.

  11. 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.

  12. 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.

  13. Solar neutrino interactions with liquid scintillators used for double beta-decay experiments

    NASA Astrophysics Data System (ADS)

    Ejiri, Hiroyasu; Zuber, Kai

    2016-08-01

    Solar neutrinos interact within double-beta-decay (DBD) detectors and hence will contribute to backgrounds (BGs) for DBD experiments. Background contributions due to solar neutrinos are evaluated for their interactions with atomic electrons and nuclei in liquid scintillation detectors used for DBD experiments. They are shown to be serious BGs for high-sensitivity DBD experiments to search for the Majorana neutrino masses in the inverted and normal hierarchy regions.

  14. 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.

  15. 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.

  16. Evaluation of a reflective coating for an organic scintillation detector

    NASA Astrophysics Data System (ADS)

    Tarancón, A.; Marin, E.; Tent, J.; Rauret, G.; Garcia, J. F.

    2012-05-01

    A reflective coating based on white paint, black paint and varnish has been evaluated to determine its reflective capabilities and its potential use in radioactivity detectors based on organic scintillators. Three different white paints, all of which were based on TiO2, were also tested to determine the one with the best performance and lowest radioactivity content. In a first experiment, we evaluated the capability of the reflective coating by measuring 90Sr/90Y with PSm in a polyethylene vial partially painted with EJ510 (Eljen Technology) reflective paint, black paint and varnish. In a second experiment, we compared the performance of the EJ510 to that of other white paints used for artistic purposes (Vallejo and Rembrandt). The results showed that, when a vial was only partially painted with the white paints (keeping a window free of paint to allow photons to exit), the efficiency and spectral distribution of the painted vial was similar to that of a non-painted vial. This behavior showed the efficiency of the reflective coatings. In terms of reflection capabilities, all of the tested paints were equivalent; however, the background was higher for the EJ510 paint. Analyses using high-resolution gamma spectroscopy indicated the presence of natural radionuclides (40K, 226Ra and 228Ra) in the EJ510. On the basis of the results (high reflection capabilities and the absence of radioactive impurities) and its lower cost, the Vallejo paint was selected as the white reflective paint. The final structure of the reflective coating was composed of five white paint layers, a black paint (to avoid external light entrance) and a layer of varnish (to protect the paints).

  17. 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.

  18. Simple algorithms for digital pulse-shape discrimination with liquid scintillation detectors

    NASA Astrophysics Data System (ADS)

    Alharbi, T.

    2015-01-01

    The development of compact, battery-powered digital liquid scintillation neutron detection systems for field applications requires digital pulse processing (DPP) algorithms with minimum computational overhead. To meet this demand, two DPP algorithms for the discrimination of neutron and γ-rays with liquid scintillation detectors were developed and examined by using a NE213 liquid scintillation detector in a mixed radiation field. The first algorithm is based on the relation between the amplitude of a current pulse at the output of a photomultiplier tube and the amount of charge contained in the pulse. A figure-of-merit (FOM) value of 0.98 with 450 keVee (electron equivalent energy) energy threshold was achieved with this method when pulses were sampled at 250 MSample/s and with 8-bit resolution. Compared to the similar method of charge-comparison this method requires only a single integration window, thereby reducing the amount of computations by approximately 40%. The second approach is a digital version of the trailing-edge constant-fraction discrimination method. A FOM value of 0.84 with an energy threshold of 450 keVee was achieved with this method. In comparison with the similar method of rise-time discrimination this method requires a single time pick-off, thereby reducing the amount of computations by approximately 50%. The algorithms described in this work are useful for developing portable detection systems for applications such as homeland security, radiation dosimetry and environmental monitoring.

  19. 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.

  20. 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.

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

    NASA Astrophysics Data System (ADS)

    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.

    2011-12-01

    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 3He) 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 μs) 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 3He-based counters measuring correlated pairs in modest (kg) samples of plutonium.

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

    SciTech Connect

    Nakae, L F; Kerr, P L; Newby, R J; Prasad, M K; Rowland, M S; Snyderman, N J; Verbeke, J M; Wurtz, R E

    2010-01-07

    For many years at LLNL we have been developing time-correlated neutron detection techniques and algorithms for many applications including Arms Control, Threat Detection and Nuclear Material Assaying. Many of our techniques have been developed specifically for relatively low efficiency (a few %) inherent in the man-portable systems. Historically we used thermal neutron detectors (mainly {sup 3}He) taking advantage of the high thermal neutron interaction cross-sections but more recently we have been investigating fast neutron detection with liquid scintillators and inorganic crystals. We have discovered considerable detection advantages with fast neutron detection as the inherent nano-second production time-scales of fission and neutron induced fission are preserved instead of being lost in neutron thermalization required for thermal neutron detectors. We are now applying fast neutron technology (new fast and portable digital electronics as well as new faster and less hazardous scintillator formulations) to the safeguards regime and faster detector response times and neutron momentum sensitivity show promise in measuring, differentiating and assaying samples that have very high count rates as well as mixed fission sources (e.g. Cm and Pu). We report on measured results with our existing liquid scintillator array and progress on design of nuclear material assaying system that incorporates fast neutron detection.

  3. 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)

  4. The Liquid Xenon Scintillation Calorimeter of the MEG Experiment:. Operation of a Large Prototype

    NASA Astrophysics Data System (ADS)

    Signorelli, Giovanni

    2005-02-01

    The MEG experiment at PSI will search for the μ → eγ decay well below the present experimental limit (BR < 1.2 × 10-11). The detection of the 52.8 MeV photon in the experiment will be done by an innovative liquid Xenon calorimeter in which only the information provided by the scintillation light is used for the photon energy and position reconstruction. The major issues concerning this calorimeter, such as transparency to scintillation light and PMT behaviour at low temperature, will be reviewed. The calorimeter has been extensively tested with various particles: α-sources, cosmic ray muons and electrons. Recently a test with high energy photons from π0 decays has been carried out at PSI: the calorimeter response to photons in an energy range very close to the final experimental conditions will be presented.

  5. Comparison of light transport-incorporated MCNPX and FLUKA codes in generating organic scintillators responses to neutrons and gamma rays

    NASA Astrophysics Data System (ADS)

    Tajik, M.; Ghal-Eh, N.

    2015-08-01

    The NE102 plastic scintillator response to 137Cs gamma rays and NE213 liquid scintillator response to both mono-energetic and 241Am-Be neutrons have been modeled using FLUKA's EVENTBIN and MCNPX's PTRAC cards. The comparison made in different energy regions confirms that the overall difference is less than 6%.

  6. Development of deep-UV sensitive MPPC for liquid xenon scintillation detector

    NASA Astrophysics Data System (ADS)

    Ootani, W.; Ieki, K.; Iwamoto, T.; Kaneko, D.; Mori, T.; Nakaura, S.; Nishimura, M.; Ogawa, S.; Sawada, R.; Shibata, N.; Uchiyama, Y.; Yoshida, K.; Sato, K.; Yamada, R.

    2015-07-01

    The liquid xenon (LXe) γ-ray detector for the MEG II experiment is based on a highly granular scintillation readout with Multi-Pixel Photon Counters (MPPCs). Here we report on the development of a large-area MPPC sensitive to LXe scintillation light in deep-UV range for the MEG II LXe detector. A prototype model of the deep-UV MPPC with an active area of 12 × 12mm2 was successfully tested in LXe, showing an excellent performance such as a high photon detection efficiency for the LXe scintillation light (about 20% at ΔV = 2.5 V), a high internal gain (about 106 at ΔV = 2.5 V) and an excellent single photoelectron resolution. The sensor chip of the MPPC is segmented into four sectors, which are then connected in series in order to reduce the overall sensor capacitance. The signal fall time of about 135 ns for the non-segmented sensor was significantly reduced down to 25 ns with the series-connected sensor segments. The preliminary results on the performance of the deep-UV MPPC are presented.

  7. 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.

  8. 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.

  9. 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. PMID:22405638

  10. 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).

  11. Mixed incineration of RAIW and liquid scintillator waste after storage for decay

    SciTech Connect

    Naba, K.; Nakazato, K.; Kataoka, K.; Imao, K.

    1993-12-31

    Most medical radioactive waste is combustible after radioactive decay. Moreover mixed incineration of LLW with biomedical radioactive waste will lessen radiation exposure to the public. This paper describes the total system flowsheet for the processing of liquid scintillator wastes and radioimmunoassay tube wastes containing iodine 125 (after a two-year storage for decay). The process was tested with a 60 kg/hr capacity incinerator from 1987 to 1991; this has been upgraded to a 150 kg/hr incinerator which is used for nonradioactive biomedical waste incineration as well.

  12. Measurement of liquid scintillation sources of (210)Pb obtained from (222)Rn decay.

    PubMed

    Antohe, A; Sahagia, M; Luca, A; Ioan, M-R; Ivan, C

    2016-03-01

    Liquid scintillation samples were filled with (222)Rn and the activity was measured with good precision after reaching the secular equilibrium with the progeny (218)Po, (214)Pb, (214)Bi and (214)Po. After decay of most of (222)Rn activity, the samples contain (210)Pb and progeny. The activities of (210)Pb and progeny can be calculated as a function of time using the initial (222)Rn activity. The samples were measured in a TDCR counter and the experimentally determined counting efficiencies are in accordance with previously published results.

  13. Measurement of liquid scintillation sources of (210)Pb obtained from (222)Rn decay.

    PubMed

    Antohe, A; Sahagia, M; Luca, A; Ioan, M-R; Ivan, C

    2016-03-01

    Liquid scintillation samples were filled with (222)Rn and the activity was measured with good precision after reaching the secular equilibrium with the progeny (218)Po, (214)Pb, (214)Bi and (214)Po. After decay of most of (222)Rn activity, the samples contain (210)Pb and progeny. The activities of (210)Pb and progeny can be calculated as a function of time using the initial (222)Rn activity. The samples were measured in a TDCR counter and the experimentally determined counting efficiencies are in accordance with previously published results. PMID:26725538

  14. Measurements of serum glucose using the luciferin/Luciferase system and a liquid scintillation spectrometer

    SciTech Connect

    Idahl, L.A.; Sandstroem, P.E.; Sehlin, J.

    1986-05-15

    A single-step assay for serum glucose measurements is described. The assay is based on the phosphorylation of D-glucose by glucokinase and the measurement of ATP consumption by firefly luciferase. The luminescence is recorded in an ordinary liquid scintillation spectrometer. The use of stable reagents and a stable final signal (light emission) makes it possible to analyze a large number of samples in each assay run. The assay is of particular value when repeated serum glucose determinations are performed on samples from small laboratory animals.

  15. 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.

  16. A rope-net support system for the liquid scintillator detector for the SNO+ experiment

    NASA Astrophysics Data System (ADS)

    Bialek, A.; Chen, M.; Cleveland, B.; Gorel, P.; Hallin, A.; Harvey, P. J.; Heise, J.; Kraus, C.; Krauss, C. B.; Lawson, I.; Ng, C. J.; Pinkney, B.; Rogowsky, D. M.; Sibley, L.; Soluk, R.; Soukup, J.; Vázquez-Jáuregui, E.

    2016-08-01

    The detector for the SNO+ experiment consists of 780 000 kg of liquid scintillator contained in an acrylic vessel that is surrounded by water. A mechanical system has been installed to counteract the 1.25 MN of buoyant force on the acrylic and prevent the vessel from moving. The system is a rope net, designed using a Finite Element Analysis to calculate the amount of stress on the acrylic induced by the ropes, hydrostatic pressures and gravity. A dedicated test was performed to measure strains in the acrylic arising from the complex geometry of the knots in the rope system. The ratio between measured and FEA calculated strains was 1.3.

  17. 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.

  18. Hybrid metal organic scintillator materials system and particle detector

    DOEpatents

    Bauer, Christina A.; Allendorf, Mark D.; Doty, F. Patrick; Simmons, Blake A.

    2011-07-26

    We describe the preparation and characterization of two zinc hybrid luminescent structures based on the flexible and emissive linker molecule, trans-(4-R,4'-R') stilbene, where R and R' are mono- or poly-coordinating groups, which retain their luminescence within these solid materials. For example, reaction of trans-4,4'-stilbenedicarboxylic acid and zinc nitrate in the solvent dimethylformamide (DMF) yielded a dense 2-D network featuring zinc in both octahedral and tetrahedral coordination environments connected by trans-stilbene links. Similar reaction in diethylformamide (DEF) at higher temperatures resulted in a porous, 3-D framework structure consisting of two interpenetrating cubic lattices, each featuring basic to zinc carboxylate vertices joined by trans-stilbene, analogous to the isoreticular MOF (IRMOF) series. We demonstrate that the optical properties of both embodiments correlate directly with the local ligand environments observed in the crystal structures. We further demonstrate that these materials produce high luminescent response to proton radiation and high radiation tolerance relative to prior scintillators. These features can be used to create sophisticated scintillating detection sensors.

  19. Measurement of the muon-induced neutron yield in liquid scintillator and stainless steel at LNGS with the LVD experiment

    SciTech Connect

    Persiani, R.; Garbini, M.; Sartorelli, G.; Selvi, M.; Collaboration: LVD Collaboration

    2013-08-08

    We describe the measurement of the muon-induced neutron yield in liquid scintillator and stainless steel (SS) at the Gran Sasso National Laboratory (LNGS), with the LVD experiment. The Large Volume Detector (LVD) is located in Hall A of the LNGS and is made of 1000 t of liquid scintillator and 1000 t of SS. Using an independent measurement to evaluate the background and with the support of a full Monte Carlo simulation based on Geant4, we measured a neutron yield of (2.9±0.6)×10{sup −4} and (1.5±0.3)×10{sup −3} in liquid scintillator and in stainless steel, respectively.

  20. [Distillation of used liquid scintillation cocktail and the possibility of re-utilization of the recovered solvent].

    PubMed

    Miyatake, H; Saito, K

    1984-03-01

    Liquid(toluene and dioxane)scintillation cocktail containing [methyl-3H]thymidine as a radioactive material was distilled by a rotary evaporator after storage for 0 to 12 months. The solvent obtained by distillation was then purified by several treatments, and the 3H-concentration in the solvent after each treatment was determined accurately. The 3H-concentration in the rotary evaporator-distillate of the cocktails reached about 0.2% of that of the original scintillation cocktails when they were stored for 12 months. But these radioactive materials could be removed completely from each solvent by several refining treatments: washing with water followed by dehydration with molecular sieves in case of toluene scintillation cocktail, and desiccation by adding excess amount of KOH in case of dioxane scintillation cocktail. It was concluded that the distillation followed by several simple refining treatments was useful to regenerate the refined solvent available for the preparation of liquid scintillation cocktail and also as a preliminary step to dispose of the waste scintillation cocktail.

  1. A neutron multiplicity analysis method for uranium samples with liquid scintillators

    NASA Astrophysics Data System (ADS)

    Zhou, Hao; Lin, Hongtao; Liu, Guorong; Li, Jinghuai; Liang, Qinglei; Zhao, Yonggang

    2015-10-01

    A new neutron multiplicity analysis method for uranium samples with liquid scintillators is introduced. An active well-type fast neutron multiplicity counter has been built, which consists of four BC501A liquid scintillators, a n/γdiscrimination module MPD-4, a multi-stop time to digital convertor MCS6A, and two Am-Li sources. A mathematical model is built to symbolize the detection processes of fission neutrons. Based on this model, equations in the form of R=F*P*Q*T could be achieved, where F indicates the induced fission rate by interrogation sources, P indicates the transfer matrix determined by multiplication process, Q indicates the transfer matrix determined by detection efficiency, T indicates the transfer matrix determined by signal recording process and crosstalk in the counter. Unknown parameters about the item are determined by the solutions of the equations. A 252Cf source and some low enriched uranium items have been measured. The feasibility of the method is proven by its application to the data analysis of the experiments.

  2. 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.

  3. 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.

  4. 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.

  5. Studies of neutron-γ pulse shape discrimination in EJ-309 liquid scintillator using charge integration method

    NASA Astrophysics Data System (ADS)

    Pawełczak, I. A.; Ouedraogo, S. A.; Glenn, A. M.; Wurtz, R. E.; Nakae, L. F.

    2013-05-01

    Pulse shape discrimination capability based on the charge integration has been investigated for liquid scintillator EJ-309. The effectiveness of neutron-γ discrimination in 4-in. diameter and 3-in. thick EJ-309 cells coupled with 3-in. photomultiplier tubes has been carefully studied in the laboratory environment and compared to the commonly used EJ-301 liquid scintillator formulation. Influences of distortions in pulse shape caused by 13.7-m long cables necessary for some remote operations have been examined. The parameter space for an effective neutron-γ discrimination for these assays, such as position and width of a gate used for integration of the delayed light, has been explored.

  6. Fast neutron tomography with real-time pulse-shape discrimination in organic scintillation detectors

    NASA Astrophysics Data System (ADS)

    Joyce, Malcolm J.; Agar, Stewart; Aspinall, Michael D.; Beaumont, Jonathan S.; Colley, Edmund; Colling, Miriam; Dykes, Joseph; Kardasopoulos, Phoevos; Mitton, Katie

    2016-10-01

    A fast neutron tomography system based on the use of real-time pulse-shape discrimination in 7 organic liquid scintillation detectors is described. The system has been tested with a californium-252 source of dose rate 163 μSv/h at 1 m and neutron emission rate of 1.5×107 per second into 4π and a maximum acquisition time of 2 h, to characterize two 100×100×100 mm3 concrete samples. The first of these was a solid sample and the second has a vertical, cylindrical void. The experimental data, supported by simulations with both Monte Carlo methods and MATLAB®, indicate that the presence of the internal cylindrical void, corners and inhomogeneities in the samples can be discerned. The potential for fast neutron assay of this type with the capability to probe hydrogenous features in large low-Z samples is discussed. Neutron tomography of bulk porous samples is achieved that combines effective penetration not possible with thermal neutrons in the absence of beam hardening.

  7. X-ray imaging with scintillator-sensitized hybrid organic photodetectors

    NASA Astrophysics Data System (ADS)

    Büchele, Patric; Richter, Moses; Tedde, Sandro F.; Matt, Gebhard J.; Ankah, Genesis N.; Fischer, Rene; Biele, Markus; Metzger, Wilhelm; Lilliu, Samuele; Bikondoa, Oier; MacDonald, J. Emyr; Brabec, Christoph J.; Kraus, Tobias; Lemmer, Uli; Schmidt, Oliver

    2015-12-01

    Medical X-ray imaging requires cost-effective and high-resolution flat-panel detectors for the energy range between 20 and 120 keV. Solution-processed photodetectors provide the opportunity to fabricate detectors with a large active area at low cost. Here, we present a disruptive approach that improves the resolution of such detectors by incorporating terbium-doped gadolinium oxysulfide scintillator particles into an organic photodetector matrix. The X-ray induced light emission from the scintillators is absorbed within hundreds of nanometres, which is negligible compared with the pixel size. Hence, optical crosstalk, a limiting factor in the resolution of scintillator-based X-ray detectors, is minimized. The concept is validated with a 256 × 256 pixel detector with a resolution of 4.75 lp mm-1 at a MTF = 0.2, significantly better than previous stacked scintillator-based flat-panel detectors. We achieved a resolution that proves the feasibility of solution-based detectors in medical applications. Time-resolved electrical characterization showed enhanced charge carrier mobility with increased scintillator filling, which is explained by morphological changes.

  8. 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.

  9. The Rayleigh ratio measurement for SNO+ liquid scintillator and background studies of the internal ropes

    NASA Astrophysics Data System (ADS)

    Asahi, Satoko

    As a successor of the Sudbury Neutrino Observatory, the SNO+ experiment is planned to start data taking in early 2013. Making use of the liquid scintillator, Linear Alkylbenzene (LAB), the SNO+ experiment aims to perform flux measurements of low energy solar neutrinos in one phase, and wait for neutrinoless double beta decay events in another phase where 44 kg of natural Neodymium would be added into LAB. The Rayleigh ratio of LAB was found to be 16.60 +/- 3.14 x 10--6 cm--1 at 546 nm using the relative measurement technique. The wavelength dependency of the Rayleigh scattering was also examined and compared with the theoretical prediction. A setup which is usable to measure the angular dependency of the Rayleigh scattering was built, and an isotropic behaviour of the scattering was tested. The beta and gamma backgrounds, due to the internal calibration ropes situated in the scintillator volume, were studied using the SNO+ Monte Carlo Package. Also, the amount of 210Pb originating from the internal calibration ropes due to the intrinsic contamination of 238U, Rn emanation and plated on the surface prior to the installation were assessed to examine if it is a tolerable level to achieve the target level of 13.4 background events per day.

  10. 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.

  11. Procedure for separation of Se and determination of Se-79 by liquid scintillation

    SciTech Connect

    Dewberry, R.A.

    1991-08-11

    This report describes the development work and demonstration of a technique for separation of selenium suitable for determination of Se-79 by liquid scintillation counting. The technique has been demonstrated on actual DWPF (Defense Waste Processing Facility) sludge samples which contain very large loads of Sr-90 activity. The separation required a decontamination of selenium from Sr by a factor of over 10{sup 6}, from Co and Cs by factor of 10{sup 4}, and from Tc-99 by a factor of 100, while still maintaining a selenium recovery of about 50%. Using this technique the author has determined Se-79 in five actual DWPF samples with a precision of about 70% relative standard deviation. This separation has not been demonstrated on actual DWPF samples which have the largest Cs-137 loads. He does not anticipate that these untested samples will present a difficult problem.

  12. 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.

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

    DOE PAGES

    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 obtainedmore » by Pacific Northwest National Laboratory.« less

  14. 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.

  15. 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)

  16. 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.

  17. Determination of 36Cl in biological shield concrete using pyrohydrolysis and liquid scintillation counting.

    PubMed

    Itoh, Mitsuo; Watanabe, Kazuo; Hatakeyama, Mutsuo; Tachibana, Mitsuo

    2002-07-01

    A method for the determination of 36Cl in biological shield concrete of nuclear reactors was developed. Cl in the concrete sample was extracted quantitatively by pyrohydrolysis at 900 degrees C and recovered in Na2CO3 solution for subsequent measurement of 36Cl by liquid scintillation counting. WO3 was used as an accelerator in the pyrohydrolysis. The Cl extraction procedure was optimized by investigating experimental conditions with the use of ion chromatography and its recovery was evaluated by the analysis of the geochemical reference samples. The detection limit of 36Cl was 0.02 Bq g(-1) for a sample weight of 2 g. The relative standard deviation was 3-7% for the samples containing 0.5 Bq g(-1) levels of 36Cl. The method was applied to determine 36Cl in biological shield concrete of the Japan Power Demonstration Reactor. PMID:12173658

  18. Determination of 235U/238U atom ratio in uranium samples using liquid scintillation counting (LSC).

    PubMed

    Alamelu, D; Aggarwal, S K

    2009-01-15

    A correlation has been developed for the determination of (235)U/(238)U atom ratio in uranium samples using liquid scintillation counting (LSC). The (235)U/(238)U atom ratio determined by thermal ionization mass spectrometry (TIMS) was correlated to the ratio of (i) alpha-count rate and (ii) Cerenkov count rate due to (234 m)Pa in the sample; both measured by LSC. This correlation is linear over the range of (235)U/(238)U atom ratio encountered in the nuclear fuel samples, i.e. the low enriched uranium (LEU) samples with (235)U<20 atom%. The methodology based on this correlation will be useful for the quick determination and verification of (235)U/(238)U atom ratios in fuel samples using cost effective technique of LSC. PMID:19064080

  19. 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.

  20. 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.

  1. Validation of efficiency tracing and zero detection threshold techniques using liquid scintillation analyser TriCarb.

    PubMed

    Reddy, P J; Bhade, S P D; Babu, D A R; Sharma, D N

    2011-11-01

    Efficiency tracing with unquenched 14C and zero detection threshold with unquenched 3H as tracers are practical and simple techniques which have been implemented to quantify the activity of various beta emitters using liquid scintillation analyser. These techniques are used to study the influence of quench level on activity quantification and the activity levels up to which these techniques are applicable. The results indicate that, for an activity level of 166.67 Bq, both the techniques are in good agreement with the reference activity with a relative discrepancy of ≤4.6 %. The relative discrepancy of ~10 % is observed for extreme quench values of ~111. For all the radionuclides with the activity level of 1.67 Bq, the uncertainty in activity quantification raises to ~8 % and for the activity level from 8.33 to 100 Bq, the uncertainty reduces to 1 %. PMID:21196460

  2. PROSPECT Background Studies and Operation of Li-Loaded Liquid Scintillator Detectors at a Research Reactor

    NASA Astrophysics Data System (ADS)

    Langford, Thomas; Prospect Collaboration

    2015-04-01

    Segmented antineutrino detectors placed near compact research reactors provide an excellent opportunity to probe short-baseline neutrino oscillations and precisely measure the reactor antineutrino spectrum. PROSPECT is a phased experiment that will explore the favored reactor anomaly parameter space at the High Flux Isotope Reactor (HFIR) at Oak Ridge National Lab. Measurements of the reactor correlated and ambient backgrounds will be presented, as well as a discussion of active and passive mitigation plans. A lithium-loaded liquid scintillator test detector is currently in operation at HFIR within a prototype shielding cave. Results from recent operation will be presented along with a discussion of their impact on PROSPECT. on behalf of the PROSPECT collaboration.

  3. Standardization of Ga-68 by coincidence measurements, liquid scintillation counting and 4πγ counting.

    PubMed

    Roteta, Miguel; Peyres, Virginia; Rodríguez Barquero, Leonor; García-Toraño, Eduardo; Arenillas, Pablo; Balpardo, Christian; Rodrígues, Darío; Llovera, Roberto

    2012-09-01

    The radionuclide (68)Ga is one of the few positron emitters that can be prepared in-house without the use of a cyclotron. It disintegrates to the ground state of (68)Zn partially by positron emission (89.1%) with a maximum energy of 1899.1 keV, and partially by electron capture (10.9%). This nuclide has been standardized in the frame of a cooperation project between the Radionuclide Metrology laboratories from CIEMAT (Spain) and CNEA (Argentina). Measurements involved several techniques: 4πβ-γ coincidences, integral gamma counting and Liquid Scintillation Counting using the triple to double coincidence ratio and the CIEMAT/NIST methods. Given the short half-life of the radionuclide assayed, a direct comparison between results from both laboratories was excluded and a comparison of experimental efficiencies of similar NaI detectors was used instead. PMID:22421395

  4. 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. PMID:20031433

  5. ecCNO solar neutrinos: A challenge for gigantic ultra-pure liquid scintillator detectors

    NASA Astrophysics Data System (ADS)

    Villante, F. L.

    2015-03-01

    Neutrinos produced in the Sun by electron capture reactions on 13N, 15O and 17F, to which we refer as ecCNO neutrinos, are not usually considered in solar neutrino analysis since the expected fluxes are extremely low. The experimental determination of this sub-dominant component of the solar neutrino flux is very difficult but could be rewarding since it provides a determination of the metallic content of the solar core and, moreover, probes the solar neutrino survival probability in the transition region at Eν ∼ 2.5 MeV. In this Letter, we suggest that this difficult measure could be at reach for future gigantic ultra-pure liquid scintillator detectors, such as LENA.

  6. 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.

  7. 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. PMID:27116402

  8. 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.

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

    PubMed

    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

    2014-11-01

    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. PMID:25430305

  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. Automated high performance liquid chromatography and liquid scintillation counting determination of pesticide mixture octanol/water partition rates

    SciTech Connect

    Moody, R.P.; Carroll, J.M.; Kresta, A.M.

    1987-12-01

    Two novel methods are reported for measuring octanol/water partition rates of pesticides. A liquid scintillation counting (LSC) method was developed for automated monitoring of /sup 14/C-labeled pesticides partitioning in biphasic water/octanol cocktail systems with limited success. A high performance liquid chromatography (HPLC) method was developed for automated partition rate monitoring of several constituents in a pesticide mixture, simultaneously. The mean log Kow +/- SD determined from triplicate experimental runs were for: 2,4-D-DMA (2,4-dichlorophenoxyacetic acid dimethylamine), 0.65 +/- .17; Deet (N,N-diethyl-m-toluamide), 2.02 +/- .01; Guthion (O,O-dimethyl-S-(4-oxo-1,2,3-benzotriazin-3(4H)-ylmethyl) phosphorodithioate), 2.43 +/- .03; Methyl-Parathion (O,O-dimethyl-O-(p-nitrophenyl) phosphorothioate), 2.68 +/- .05; and Fenitrothion (O,O-dimethyl O-(4-nitro-m-tolyl) phosphorothioate), 3.16 +/- .03. A strong positive linear correlation (r = .9979) was obtained between log Kow and log k' (log Kow = 2.35 (log k') + 0.63). The advantages that this automated procedure has in comparison with the standard manual shake-flask procedure are discussed.

  13. The performance of MACRO liquid scintillator in the search for magnetic monopoles with 10^-3

    NASA Astrophysics Data System (ADS)

    MACRO Collaboration; Ambrosio, M.; Antolini, R.; Auriemma, G.; Baker, R.; Baldini, A.; Barbarino, G. C.; Barish, B. C.; Battistoni, G.; Bellotti, R.; Bemporad, C.; Bernardini, P.; Bilokon, H.; Bisi, V.; Bloise, C.; Bosio, T.; Bower, C.; Bussino, S.; Cafagna, R.; Calicchio, M.; Campana, D.; Carboni, M.; Castellano, M.; Cecchini, S.; Cei, F.; Chiarella, V.; Corona, A.; Coutu, S.; de Cataldo, G.; Dekhissi, H.; de Marzo, C.; de Mitri, I.; de Vincenzi, M.; di Credico, A.; Erriquez, O.; Fantini, R.; Favuzzi, C.; Forti, C.; Fusco, P.; Giacomelli, G.; Giannini, G.; Giglietto, N.; Goretti, M.; Grassi, M.; Green, P.; Grillo, A.; Guarino, F.; Guarnaccia, P.; Gustavino, C.; Habig, A.; Hanson, K.; Hawthorne, A.; Heinz, R.; Hong, J. T.; Iarocci, E.; Katsavounidis, E.; Kearns, E.; Kyriazopoulou, S.; Lamanna, E.; Lane, C.; Levin, D. S.; Lipari, P.; Liu, G.; Liu, R.; Longley, N. P.; Longo, M. J.; Ludlam, G.; Mancarella, G.; Mandrioli, G.; Margiotta-Neri, A.; Marini, A.; Martello, D.; Marzari-Chiesa, A.; Mazziotta, M. N.; Michael, D. G.; Mikheyev, S.; Miller, L.; Monacelli, P.; Montaruli, T.; Monteno, M.; Mufson, S.; Musser, J.; Nicoló, D.; Nolty, R.; Okada, C.; Orth, C.; Osteria, G.; Palamara, O.; Parlati, S.; Patera, V.; Patrizii, L.; Pazzi, R.; Peck, C. W.; Petrera, S.; Pignatano, N. D.; Pistilli, P.; Popa, V.; Rainó, A.; Reynoldson, J.; Ronga, F.; Rubizzo, U.; Sanzgiri, A.; Sartogo, F.; Satriano, C.; Satta, L.; Scapparone, E.; Scholberg, K.; Sciubba, A.; Serra-Lugaresi, P.; Severi, M.; Sinev, V.; Sitta, M.; Spinelli, P.; Spinetti, M.; Spurio, M.; Steinberg, R.; Stone, J. L.; Sulak, L. R.; Surdo, A.; Tarlé, G.; Togo, V.; Valente, V.; Walter, C. W.; Webb, R.

    1997-02-01

    MACRO is designed to make a multiply redundant search for GUT magnetic monopoles over a wide velocity range. The 100 MHz pulse height recorder and synchronous encoder (PHRASE) and the energy reconstruction processor (ERP) are two components of that search, both based on the MACRO liquid scintillator. They are sensitive to monopoles with or without captured nuclei in the range beta~10^-3 to beta~1. Here, the performance of these systems is discussed, including also analysis methods and background evaluations.

  14. 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.

  15. Getting the most from the detection of Galactic supernova neutrinos in future large liquid-scintillator detectors

    NASA Astrophysics Data System (ADS)

    Lu, Jia-Shu; Li, Yu-Feng; Zhou, Shun

    2016-07-01

    Future large liquid-scintillator detectors can be implemented to observe neutrinos from a core-collapse supernova in our Galaxy in various reaction channels: (1) the inverse beta decay ν¯ e+p →n +e+ , (2) the elastic neutrino-proton scattering ν +p →ν +p , (3) the elastic neutrino-electron scattering ν +e-→ν +e- , (4) the charged-current νe interaction νe+12C →e-+12N, (5) the charged-current ν¯ e interaction ν¯ e+12C →e++12B, and (6) the neutral-current interaction ν +12C →ν +12C* The less abundant 13C atoms in the liquid scintillator are also considered as a target, and both the charged-current interaction νe+13C →e-+13N and the neutral-current interaction ν +13C →ν +13C* are taken into account. In this work, we show for the first time that a global analysis of all these channels at a single liquid-scintillator detector, such as Jiangmen Underground Neutrino Observatory, is very important to test the average-energy hierarchy of supernova neutrinos and how the total energy is partitioned among neutrino flavors. In addition, the dominant channels for reconstructing neutrino spectra and the impact of other channels are discussed in great detail.

  16. An emergency urine bioassay method for 241Am by extraction chromatography and liquid scintillation counting.

    PubMed

    Sadi, Baki B; Li, Chunsheng; Masoud, Ali; Ko, Raymond; Kramer, Gary H

    2010-09-01

    An emergency urine bioassay method has been developed for the determination of (241)Am in human urine samples. The method is based on extraction chromatographic separation of (241)Am from urine on a single DGA (N,N,N',N'-tetraoctyldiglycolamide) resin column followed by liquid scintillation counting of (241)Am. The minimum detectable activity (MDA) for the method was 0.02 Bq. Considering the volume of urine sample (17.2 ml) used by the method; the MDA was 1.3 Bq l(-1). Measurement accuracy (relative bias, B(r)) and repeatability (relative precision, S(B)) of the method were found to be -3.4 and 8.9 %, respectively, when urine samples were spiked with (241)Am (20 Bq l(-1)). Excellent linearity (r(2) > 0.999) was established over the range of 2-200 Bq l(-1). The method was also found to be robust (S(B)=10.2 %) against matrix effects from different urine samples. Performance of the rapid bioassay method for accuracy and repeatability were evaluated against the performance criteria for radiobioassay (ANSI N13.30) and found to be in compliance. Considering the simplicity, excellent analytical figures of merit and fast sample turnaround time (<1 h), it is a very promising rapid bioassay method for supporting the medical response to an emergency where internal contamination of (241)Am is involved.

  17. 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)

  18. Measurement of 90Sr in contaminated Fukushima soils using liquid scintillation counter.

    PubMed

    Kavasi, N; Sahoo, S K; Arae, H; Yoshida, S; Sorimachi, A; Tokonami, S

    2015-11-01

    A method based on liquid scintillation counting system has been developed for the measurement of (90)Sr in Fukushima soil samples due to contamination of (134)Cs and (137)Cs. Three soil samples were collected within 30 km radius from the Fukushima Daiichi Nuclear Power Plant (FDNPP). Activity concentration of (134)Cs and (137)Cs were measured using a gamma spectroscopy system with high-purity germanium detector. (90)Sr contamination is little elevated but comparable with the background contamination level that originated from atmospheric nuclear weapon tests, whereas radiocesium contamination has increased significantly. Activity concentration of (90)Sr in the soil samples varied in the range of 10.4±0.6-22.0±1.2 Bq kg(-1). Activity concentrations of (134)Cs and (137)Cs in the soil samples were in the range of 28.2±0.2-56.3±0.2 kBq kg(-1) and 35.2±0.1-70.2±0.2 kBq kg(-1), respectively (reference date for decay correction is 1 December 2011). PMID:25956786

  19. PSA discriminator influence on (222)Rn efficiency detection in waters by liquid scintillation counting.

    PubMed

    Stojković, Ivana; Todorović, Nataša; Nikolov, Jovana; Tenjović, Branislava

    2016-06-01

    A procedure for the (222)Rn determination in aqueous samples using liquid scintillation counting (LSC) was evaluated and optimized. Measurements were performed by ultra-low background spectrometer Quantulus 1220™ equipped with PSA (Pulse Shape Analysis) circuit which discriminates alpha/beta spectra. Since calibration procedure is carried out with (226)Ra standard, which has both alpha and beta progenies, it is clear that PSA discriminator has vital importance in order to provide precise spectra separation. Improvement of calibration procedure was done through investigation of PSA discriminator level and, consequentially, the activity of (226)Ra calibration standard influence on (222)Rn efficiency detection. Quench effects on generated spectra i.e. determination of radon efficiency detection were also investigated with quench calibration curve obtained. Radon determination in waters based on modified procedure according to the activity of (226)Ra standard used, dependent on PSA setup, was evaluated with prepared (226)Ra solution samples and drinking water samples with assessment of measurement uncertainty variation included. PMID:27016710

  20. 234Th analysis of marine sediments via extraction chromatography and liquid scintillation counting.

    PubMed

    Nour, Svetlana; Burnett, William C; Horwitz, E Philip

    2002-08-01

    234Th is widely used as a natural tracer for study of biological mixing and particle scavenging processes in the ocean. This naturally occurring nuclide serves this purpose due to its convenient half-life (24.1 days), constant rate of production from 238U dissolved in seawater, and its strong tendency to attach to particles in seawater. As a beta/gamma emitter, 234Th may be determined using low-level gas-flow proportional counting, gamma spectrometry, and liquid scintillation counting (LSC). We describe here a technique which combines Cerenkov counting to evaluate 234Th (via 234Pa) with LSC alpha counting of 230Th added to the samples as a yield tracer. Our separation approach is based on a sample preparation procedure for marine sediments using nitric acid leaching in a "hot block", and extraction chromatography (TEVA x Resin) for Th isolation. Samples are counted in plastic LSC vials, using Ultima Gold AB cocktail, in 1 M H3PO4 media. A series of sediment samples spiked with known amounts of 234Th yielded activities within a few percent of the anticipated values. PMID:12150283

  1. 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.

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

    DOE PAGES

    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 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

  3. Aging of LAB-based liquid scintillator in stainless steel containers

    NASA Astrophysics Data System (ADS)

    Chen, Hai-Tao; Yu, Bo-Xiang; Shan, Qing; Ding, Ya-Yun; Du, Bing; Liu, Shu-Tong; Zhang, Xuan; Zhou, Li; Jia, Wen-Bao; Fang, Jian; Ye, Xing-Chen; Hu, Wei; Niu, Shun-Li; Yan, Jia-Qing; Zhao, Hang; Hong, Dao-Jin

    2015-06-01

    Types 316 and 304 stainless steel are two candidates for the storage vessels and piping systems of LAB-based liquid scintillator (LS) in the JUNO experiment. LS aging experiments are carried out at temperatures of 40 °C and 25 °C. After 192 days aging at 40 °C, the attenuation length of LS was reduced by 6% in a glass container, 12% in a type 304 stainless steel tank, and 10% in a type 316 stainless steel tank. At 25 °C in 304 and 316 stainless steel tanks, the attenuation length was reduced by 6% after 307 days. The light yield and the absorption spectrum were practically the same as that of the unaged sample. The concentration of element Fe in the LAB-based LS did not show a clear change. Type 316 and 304 stainless steel can be used as vessels and transportation pipeline material for LAB-based LS. Supported by Strategic Priority Research Program of the Chinese Academy of Sciences (XDA10010500) and National Natural Science Foundation of China (11205183, 11005117, 11225525, 11390384)

  4. 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.

  5. 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.

  6. Calibration of a liquid scintillation counter for alpha, beta and Cerenkov counting

    SciTech Connect

    Scarpitta, S.C.; Fisenne, I.M.

    1996-07-01

    Calibration data are presented for 25 radionuclides that were individually measured in a Packard Tri-Carb 2250CA liquid scintillation (LS) counter by both conventional and Cerenkov detection techniques. The relationships and regression data between the quench indicating parameters and the LS counting efficiencies were determined using microliter amounts of tracer added to low {sup 40}K borosilicate glass vials containing 15 mL of Insta-Gel XF scintillation cocktail. Using {sup 40}K, the detection efficiencies were linear over a three order of magnitude range (10 - 10,000 mBq) in beta activity for both LS and Cerenkov counting. The Cerenkov counting efficiency (CCE) increased linearly (42% per MeV) from 0.30 to 2.0 MeV, whereas the LS efficiency was >90% for betas with energy in excess of 0.30 MeV. The CCE was 20 - 50% less than the LS counting efficiency for beta particles with maximum energies in excess of 1 MeV. Based on replicate background measurements, the lower limit of detection (LLD) for a 1-h count at the 95% confidence level, using water as a solvent, was 0.024 counts sec-{sup -1} and 0.028 counts sec-1 for plastic and glass vials, respectively. The LLD for a 1-h-count ranged from 46 to 56 mBq (2.8 - 3.4 dpm) for both Cerenkov and conventional LS counting. This assumes: (1) a 100% counting efficiency, (2) a 50% yield of the nuclide of interest, (3) a 1-h measurement time using low background plastic vials, and (4) a 0-50 keV region of interest. The LLD is reduced an order of magnitude when the yield recovery exceeds 90% and a lower background region is used (i.e., 100 - 500 keV alpha region of interest). Examples and applications of both Cerenkov and LS counting techniques are given in the text and appendices.

  7. Determining the 222Rn exhalation rate of building materials using liquid scintillation counting.

    PubMed

    van Dijk, W; de Jong, P

    1991-10-01

    A new method for determining the free 222Rn exhalation rate from building materials is described. The sample is enclosed in a container from which the exhaled Rn is continuously purged by nitrogen gas. After 2-3 h, when the Rn level in the container has reached a steady-state concentration, the outflowing Rn is trapped on silica gel at about -190 degrees C. About 16 h after sampling, the silica gel is analyzed by liquid scintillation counting to determine the area exhalation rate. The method described has a good repeatability and reproducibility with coefficients of variation of 7.8% and 8.3%, respectively, at 5 Bq m-2 h-1. The low limit of detection of 11 mBq 222Rn offers the opportunity to quantify the exhalation rate of almost all kinds of building materials. It was found that the air humidity strongly influences the exhalation rates of building material and, therefore, should be controlled. Two typical building materials were investigated. For gypsum, an increase in the exhalation rate with increasing water vapor pressure was found, whereas for concrete, a linear decrease with increasing water vapor pressure was observed. The 222Rn area exhalation rates of 20 Dutch building materials, including some experimental ones, were determined at 50% RH, 20 degrees C, showing a range of less than 0.02-15.8 Bq m-2 h-1. The lowest values were found for natural gypsum board, the highest for phosphogypsum blocks. Building materials containing fly ash gave area exhalation rates comparable to those of similar materials without fly ash.

  8. Scintillation proximity assay using polymeric membranes

    SciTech Connect

    Mansfield, R.K.

    1992-01-01

    Liquid scintillation counting (LSC) is typically used to quantify electron emitting isotopes. In LSC, radioactive samples are dissolved in an organic fluor solution (scintillation cocktail) to ensure that the label is close enough to the fluor molecules to be detected. Although efficient, scintillation cocktail is neither specific or selective for samples labeled with the same radioisotope. Scintillation cocktail is flammable posing significant health risks to the user and is expensive to purchase and discard. Scintillation Proximity Assay (SPA) is a radioanalytical technique where only those radiochemical entities (RCE's) bound to fluor containing matrices are detected. Only bound RCE's are in close enough proximity the entrapped fluor molecules to induce scintillations. Unbound radioligands are too far removed from the fluor molecules to be detected. The research in this dissertation focused on the development and evaluation of fluor-containing membranes (scintillation proximity membranes, SP membranes) to be used for specific radioanalytical techniques without using scintillation cocktail. Polysulfone and PVC SP membranes prepared in our laboratory were investigated for radioimmunossay (RIA) where only bound radioligand is detected, thereby eliminating the separation step impeding the automation of RIA. These SP membranes performed RIA where the results were nearly identical to commercial SP microbeads. SP membranes functionalized with quaternary ammonium hydroxide moieties were able to trap and quantify [sup 14]CO[sub 2] without using liquid scintillation cocktail. RCE's bound in the pore structure of SP membranes are intimate with the entrapped fluor providing the geometry needed for high detection efficiencies. Absorbent SP membranes were used in radiation surveys and were shown to be as effective as conventional survey techniques using filter paper and scintillation cocktail.

  9. REMOVAL OF URANIUM FROM ORGANIC LIQUIDS

    DOEpatents

    Vavalides, S.P.

    1959-08-25

    A process is described for recovering small quantities of uranium from organic liquids such as hydrocarbon oils. halogen-substituted hydrocarbons, and alcohols. The organic liquid is contacted with a comminuted alkaline earth hydroxide, calcium hydroxide particularly, and the resulting uranium-bearing solid is separated from the liquid by filtration. Uranium may then be recovered from the solid by means of dissolution in nitric acid and conventional extraction with an organic solvent such as tributyl phosphate.

  10. 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.

  11. Digital discrimination of neutrons and gamma-rays in organic scintillation detectors using moment analysis

    SciTech Connect

    Xie Xufei; Zhang Xing; Yuan Xi; Chen Jinxiang; Li Xiangqing; Zhang Guohui; Fan Tieshuan; Yuan Guoliang; Yang Jinwei; Yang Qingwei

    2012-09-15

    Digital discrimination of neutron and gamma-ray events in an organic scintillator has been investigated by moment analysis. Signals induced by an americium-beryllium (Am/Be) isotropic neutron source in a stilbene crystal detector have been sampled with a flash analogue-to-digital converter (ADC) of 1 GSamples/s sampling rate and 10-bit vertical resolution. Neutrons and gamma-rays have been successfully discriminated with a threshold corresponding to gamma-ray energy about 217 keV. Moment analysis has also been verified against the results assessed by a time-of-flight (TOF) measurement. It is shown that the classification of neutrons and gamma-rays afforded by moment analysis is consistent with that achieved by digital TOF measurement. This method has been applied to analyze the data acquired from the stilbene crystal detector in mixed radiation field of the HL-2A tokamak deuterium plasma discharges and the results are described.

  12. Digital discrimination of neutrons and gamma-rays in organic scintillation detectors using moment analysis

    NASA Astrophysics Data System (ADS)

    Xie, Xufei; Zhang, Xing; Yuan, Xi; Chen, Jinxiang; Li, Xiangqing; Zhang, Guohui; Fan, Tieshuan; Yuan, Guoliang; Yang, Jinwei; Yang, Qingwei

    2012-09-01

    Digital discrimination of neutron and gamma-ray events in an organic scintillator has been investigated by moment analysis. Signals induced by an americium-beryllium (Am/Be) isotropic neutron source in a stilbene crystal detector have been sampled with a flash analogue-to-digital converter (ADC) of 1 GSamples/s sampling rate and 10-bit vertical resolution. Neutrons and gamma-rays have been successfully discriminated with a threshold corresponding to gamma-ray energy about 217 keV. Moment analysis has also been verified against the results assessed by a time-of-flight (TOF) measurement. It is shown that the classification of neutrons and gamma-rays afforded by moment analysis is consistent with that achieved by digital TOF measurement. This method has been applied to analyze the data acquired from the stilbene crystal detector in mixed radiation field of the HL-2A tokamak deuterium plasma discharges and the results are described.

  13. Design of organic scintillators for non-standard radiation field dosimetry: experimental setup.

    PubMed

    Norman H, Machado R; Maximiliano, Trujillo T; Javier E, García G; Diana C, Narvaez G; Paula A, Marín M; Róbinson A, Torres V

    2013-01-01

    This paper describes an experimental setup designed for sensing the luminescent light coming from an organic plastic scintillator stimulated with ionizing radiation. This device is intended to be a part of a complete dosimeter system for characterization of small radiation fields which is the project of the doctoral thesis of the medical physicist at the Radiation Oncology facility of Hospital San Vicente Fundación in conjunction with the Universidad de Antioquia of Medellín Colombia. Some preliminary results predict a good performance of the unit, but further studies must be conducted in order to have a completed evaluation of the system. This is the first step in the development of an accuracy tool for measurement of non-standard fields in the Radiotherapy or Radiosurgery processes. PMID:24110369

  14. 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. PMID:24560852

  15. 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.

  16. Assessment of drinking water radioactivity content by liquid scintillation counting: set up of high sensitivity and emergency procedures.

    PubMed

    Rusconi, R; Azzellino, A; Bellinzona, S; Forte, M; Gallini, R; Sgorbati, G

    2004-05-01

    In our institute, different procedures have been developed to measure the radioactivity content of drinking water both in normal and in emergency situations, such as those arising from accidental and terrorist events. A single radiometric technique, namely low level liquid scintillation counting (LSC), has been used. In emergency situations a gross activity screening is carried out without any sample treatment by a single and quick liquid scintillation counting. Alpha and beta activities can be measured in more than one hundred samples per day with sensitivities of a few Bq/L. Higher sensitivity gross alpha and beta, uranium and radium measurements can be performed on water samples after specific sample treatments. The sequential method proposed is designed in such a way that the same water sample can be used in all the stages, with slight modifications. This sequential procedure was applied in a survey of the Lombardia district. At first tap waters of the 13 largest towns were examined, then a more detailed monitoring was carried out in the surroundings of Milano and Lodi towns. The high sensitivity method for the determination of uranium isotopes was used to check the presence of depleted uranium in Lake Garda. Reduced equipment requirements and relative readiness of radiochemical procedures make LSC an attractive technique which can also be applied by laboratories lacking specific radiochemistry facilities and experience.

  17. 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.

  18. 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

  19. Neutron detector based on Particles of 6Li glass scintillator dispersed in organic lightguide matrix

    NASA Astrophysics Data System (ADS)

    Ianakiev, K. D.; Hehlen, M. P.; Swinhoe, M. T.; Favalli, A.; Iliev, M. L.; Lin, T. C.; Bennett, B. L.; Barker, M. T.

    2015-06-01

    Most 3He replacement neutron detector technologies today have overlapping neutron-gamma pulse-height distributions, which limits their usefulness and performance. Different techniques are used to mitigate this shortcoming, including Pulse Shape Discrimination (PSD) or threshold settings that suppress all gammas as well as much of the neutrons. As a result, count rates are limited and dead times are high when PSD is used, and the detection efficiency for neutron events is reduced due to the high threshold. This is a problem in most applications where the neutron-gamma separation of 3He detectors had been essential. This challenge is especially severe for neutron coincidence and multiplicity measurements that have numerous conflicting requirements such as high detection efficiency, short die-away time, short dead time, and high stability. 6Li-glass scintillators have excellent light output and a single peak distribution, but they are difficult to implement because of their gamma sensitivity. The idea of reducing the gamma sensitivity of 6Li-glass scintillators by embedding small glass particles in an organic light-guide medium was first presented by L.M. Bollinger in the early 60s but, to the best of our knowledge, has never been reduced to practice. We present a proof of principle detector design and experimental data that develop this concept to a large-area neutron detector. This is achieved by using a multi-component optical medium (6Li glass particles attached to a glass supporting structure and a mineral oil light guide) which matches the indices of refraction and minimizes the absorption of the 395 nm scintillator light. The detector design comprises a 10 in. long tube with dual end readout with about 3% volume density of 6Li glass particles installed. The presented experimental data with various neutron and gamma sources show the desired wide gap between the neutron and gamma pulse height distributions, resulting in a true plateau in the counting

  20. Nanoparticles in ionic liquids: interactions and organization.

    PubMed

    He, Zhiqi; Alexandridis, Paschalis

    2015-07-28

    Ionic liquids (ILs), defined as low-melting organic salts, are a novel class of compounds with unique properties and a combinatorially great chemical diversity. Ionic liquids are utilized as synthesis and dispersion media for nanoparticles as well as for surface functionalization. Ionic liquid and nanoparticle hybrid systems are governed by a combined effect of several intermolecular interactions between their constituents. For each interaction, including van der Waals, electrostatic, structural, solvophobic, steric, and hydrogen bonding, the characterization and quantitative calculation methods together with factors affecting these interactions are reviewed here. Various self-organized structures based on nanoparticles in ionic liquids are generated as a result of a balance of these intermolecular interactions. These structures, including colloidal glasses and gels, lyotropic liquid crystals, nanoparticle-stabilized ionic liquid-containing emulsions, ionic liquid surface-functionalized nanoparticles, and nanoscale ionic materials, possess properties of both ionic liquids and nanoparticles, which render them useful as novel materials especially in electrochemical and catalysis applications. This review of the interactions within nanoparticle dispersions in ionic liquids and of the structure of nanoparticle and ionic liquid hybrids provides guidance on the rational design of novel ionic liquid-based materials, enabling applications in broad areas.

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

    PubMed Central

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

    2011-01-01

    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 3H-tetracycline (3H-TC) and 45Ca as markers of bone turnover in mice. Individual samples were prepared over a wide range of known 45Ca/3H activity ratios. Results showed that 45Ca/3H 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 45Ca/3H activity ratios in range of 2–10 (percentage difference ~ 20–30%). Urine and fecal samples from mice administered with both 3H-TC and 45Ca were analyzed with the dual-label method. Positive correlations between 3H and 45Ca in urine (R = 0.93) and feces (R = 0.83) indicate that 3H-TC and 45Ca can be interchangeably used to monitor longitudinal in vivo skeletal remodeling. PMID:21900015

  2. 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. PMID:20837602

  3. A sub-boiling distillation method for the preparation of low carbon content water from urine samples for tritium measurement by liquid scintillation counting.

    PubMed

    Nogawa, N; Makide, Y

    1999-06-01

    A new preparation method was developed for obtaining low carbon content water from urine samples for the measurement of tritium by a liquid scintillation counter. The method uses a simple and convenient subboiling distillation bottle. Many urine samples have been purified by this method and the change of tritium level in a tritium-handling radiation-worker was observed.

  4. Characterization of fluor concentration and geometry in organic scintillators for in situ beta imaging

    SciTech Connect

    Tornai, M.P.; Hoffman, E.J.; MacDonald, L.R.; Levin, C.S.

    1996-12-01

    Development of a small area (1--2 cm{sup 2}) in situ beta imaging device includes optimization of the front end scintillation detector, which is fiber optically coupled to a remote photon detector. Thin plastic scintillation detectors, which are sensitive to charged particles, are the ideal detectors due to the low sensitivity to ambient gamma backgrounds. The light output of a new binary plastic scintillator was investigated with respect to increasing concentrations of the fluor (0.5--2.0% by weight) and varying thickness cylindrical configurations of the intended imaging detector. The fluor had an emission maximum increasing from 431 to 436 nm with increasing fluor concentration. The decay time(s) had two components (0.38 and 1.74 ns). There was an {approximately}20% increase in light output with increasing fluor concentration measured with both {sup 204}Tl betas and conversion electrons from {sup 207}Bi. The highest light output of this new scintillator was measured to be {approximately}30% lower than BC404. Simulations predicted the 1.5 mm scintillator thickness at which light output and energy absorption for {approximately}700 keV electrons (e.g., from {sup 204}Tl, {sup 18}F) were maximized, which corresponded with measurements. As beta continua are relatively featureless, energy calibration for the thin scintillators was investigated using Landau distributions, which appear as distinct peaks in the spectra. As the scintillators were made thinner, gamma backgrounds were shown to linearly decrease.

  5. NOCHAR Polymers: An Aqueous and Organic Liquid Solidification Process for Cadarache LOR (Liquides Organiques Radioactifs) - 13195

    SciTech Connect

    Vaudey, Claire-Emilie; Renou, Sebastien; Porco, Julien; Kelley, Dennis; Cochaud, Chantal

    2013-07-01

    To handle the Very Low Level Waste (VLLW) and the Low Level Waste (LLW) in France, two options can be considered: the incineration at CENTRACO facility and the disposal facility on ANDRA sites. The waste acceptance in these radwaste routes is dependent upon the adequacy between the waste characteristics (physical chemistry and radiological) and the radwaste route specifications. If the waste characteristics are incompatible with the radwaste route specifications (presence of significant quantities of chlorine, fluorine, organic component etc or/and high activity limits), it is necessary to find an alternative solution that consists of a waste pre-treatment process. In the context of the problematic Cadarache LOR (Liquides Organiques Radioactifs) waste streams, two radioactive scintillation cocktails have to be treated. The first one is composed of organic liquids at 13.1 % (diphenyloxazol, mesitylene, TBP, xylene) and water at 86.9 %. The second one is composed of TBP at 8.6 % and water at 91.4 %. They contain chlorine, fluorine and sulphate and have got alpha/beta/gamma spectra with mass activities equal to some kBq.g{sup -1}. Therefore, tritium is present and creates the second problematic waste stream. As a consequence, in order for disposal acceptance at the ANDRA site, it is necessary to pre-treat the waste. The NOCHAR polymers as an aqueous and organic liquid solidification process seem to be an adequate solution. Indeed, these polymers constitute an important variety of products applied to the treatment of radioactive aqueous and organic liquids (solvent, oil, solvent/oil mixing etc) and sludge through a mechanical and chemical solidification process. For Cadarache LOR, N910 and N960 respectively dedicated to the organic and aqueous liquids solidification are considered. With the N910, the organic waste solidification occurs in two steps. As the organic liquid travels moves through the polymer strands, the strands swell and immobilise the liquid. Then as the

  6. Relative light yield and temporal response of a stilbene-doped bibenzyl organic scintillator for neutron detection

    SciTech Connect

    Brown, J. A.; Goldblum, B. L. Brickner, N. M.; Daub, B. H.; Kaufman, G. S.; Bibber, K. van; Vujic, J.; Bernstein, L. A.; Bleuel, D. L.; Caggiano, J. A.; Hatarik, R.; Phillips, T. W.; Zaitseva, N. P.; Wender, S. A.

    2014-05-21

    The neutron time-of-flight (nTOF) diagnostics used to characterize implosions at the National Ignition Facility (NIF) has necessitated the development of novel scintillators that exhibit a rapid temporal response and high light yield. One such material, a bibenzyl-stilbene mixed single-crystal organic scintillator grown in a 99.5:0.5 ratio in solution, has become the standard scintillator used for nTOF diagnostics at NIF. The prompt fluorescence lifetime and relative light yield as a function of proton energy were determined to calibrate this material as a neutron detector. The temporal evolution of the intensity of the prompt fluorescent response was modeled using first-order reaction kinetics and the prompt fluorescence decay constant was determined to be 2.46 ± 0.01 (fit) ± 0.13 (systematic) ns. The relative response of the bibenzyl-stilbene mixed crystal generated by recoiling protons was measured, and results were analyzed using Birks' relation to quantify the non-radiative quenching of excitation energy in the scintillator.

  7. 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.

  8. Activity standardisation of ²²⁶Ra by 4πα liquid scintillation counting method.

    PubMed

    Havelka, Miroslav; Bluďovský, Richard

    2013-11-01

    Activity of (226)Ra in radium daughter products free solution was determined by 4πα liquid scintillation counting (LSC) method, where the detection efficiency of radium decay is practically equal to 1. The sources were prepared from solution with known (226)Ra mass concentration, from which, immediately before LS counting, (222)Rn and its daughter nuclides were removed by solvent extraction. LS counting results were corrected practically only for a <0.6% loss of radium from measured sample and for the ingrowth of (222)Rn and (218)Po concentrations in the sample after the separation was completed. The combined relative standard uncertainty was estimated to be lower than 0.34%.

  9. 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.

  10. Measurement of the {sup 8}B solar neutrino flux with the KamLAND liquid scintillator detector

    SciTech Connect

    Abe, S.; Furuno, K.; Gando, A.; Gando, Y.; Ichimura, K.; Ikeda, H.; Kibe, Y.; Kimura, W.; Kishimoto, Y.; Minekawa, Y.; Mitsui, T.; Morikawa, T.; Nagai, N.; Nakajima, K.; Nakamura, M.; Narita, K.; Shimizu, I.; Shimizu, Y.; Shirai, J.; Suekane, F.

    2011-09-15

    We report a measurement of the neutrino-electron elastic scattering rate from {sup 8}B solar neutrinos based on a 123 kton-day exposure of KamLAND. The background-subtracted electron recoil rate, above a 5.5-MeV analysis threshold is 1.49 {+-} 0.14(stat) {+-} 0.17(syst) events per kton-day. Interpreted as due to a pure electron flavor flux with a {sup 8}B neutrino spectrum, this corresponds to a spectrum integrated flux of 2.77 {+-} 0.26(stat) {+-} 0.32(syst) x10{sup 6} cm{sup -2}s{sup -1}. The analysis threshold is driven by {sup 208}Tl present in the liquid scintillator, and the main source of systematic uncertainty is due to background from cosmogenic {sup 11}Be. The measured rate is consistent with existing measurements and with standard solar model predictions which include matter-enhanced neutrino oscillation.

  11. 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.

  12. Warhead verification as inverse problem: Applications of neutron spectrum unfolding from organic-scintillator measurements

    NASA Astrophysics Data System (ADS)

    Lawrence, Chris C.; Febbraro, Michael; Flaska, Marek; Pozzi, Sara A.; Becchetti, F. D.

    2016-08-01

    Verification of future warhead-dismantlement treaties will require detection of certain warhead attributes without the disclosure of sensitive design information, and this presents an unusual measurement challenge. Neutron spectroscopy—commonly eschewed as an ill-posed inverse problem—may hold special advantages for warhead verification by virtue of its insensitivity to certain neutron-source parameters like plutonium isotopics. In this article, we investigate the usefulness of unfolded neutron spectra obtained from organic-scintillator data for verifying a particular treaty-relevant warhead attribute: the presence of high-explosive and neutron-reflecting materials. Toward this end, several improvements on current unfolding capabilities are demonstrated: deuterated detectors are shown to have superior response-matrix condition to that of standard hydrogen-base scintintillators; a novel data-discretization scheme is proposed which removes important detector nonlinearities; and a technique is described for re-parameterizing the unfolding problem in order to constrain the parameter space of solutions sought, sidestepping the inverse problem altogether. These improvements are demonstrated with trial measurements and verified using accelerator-based time-of-flight calculation of reference spectra. Then, a demonstration is presented in which the elemental compositions of low-Z neutron-attenuating materials are estimated to within 10%. These techniques could have direct application in verifying the presence of high-explosive materials in a neutron-emitting test item, as well as other for treaty verification challenges.

  13. 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.

  14. Integrated readout of organic scintillator and ZnS:Ag/6LiF for segmented antineutrino detectors.

    SciTech Connect

    Kiff, Scott D.; Reyna, David; Monahan, James; Bowden, Nathaniel S.

    2010-11-01

    Antineutrino detection using inverse beta decay conversion has demonstrated the capability to measure nuclear reactor power and fissile material content for nuclear safeguards. Current efforts focus on aboveground deployment scenarios, for which highly efficient capture and identification of neutrons is needed to measure the anticipated antineutrino event rates in an elevated background environment. In this submission, we report on initial characterization of a new scintillation-based segmented design that uses layers of ZnS:Ag/{sup 6}LiF and an integrated readout technique to capture and identify neutrons created in the inverse beta decay reaction. Laboratory studies with multiple organic scintillator and ZnS:Ag/{sup 6}LiF configurations reliably identify {sup 6}Li neutron captures in 60 cm-long segments using pulse shape discrimination.

  15. 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. PMID:23415246

  16. 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.

  17. Design Considerations for a Large Metal-Loaded Liquid Scintillator Detector with Applications for Solar Neutrino and Double Beta Decay Studies

    NASA Astrophysics Data System (ADS)

    Doe, Peter; Robertson, Hamish; Gehman, Victor; Gehring, George; Iwamoto, Hideko; Will, Doug

    2002-10-01

    The realization of a large, metal-loaded liquid scintillator detector has exciting possibilities in the areas of Double Beta Decay, low-energy solar neutrino, and supernova neutrino studies. We have used statistical considerations to arrive at an analytical expression which will allow us to optimize a detector design for energy and spatial resolution. Using these results, we consider the possible use of Avalanche Photo-Diode detectors operated in the Geiger regime as a possible replacement for Photomultiplier Tubes.

  18. A mechanism for supercooling in organic liquids

    SciTech Connect

    Thoma, P.E.

    1996-12-31

    In this investigation, a mechanism for supercooling inorganic liquids is formulated. By comparing the melting temperature and spontaneous freezing temperature of the chemicals evaluated with their molecular characteristics, the factors promoting supercooling are developed. The results obtained indicate that the following molecular characteristics promote supercooling in organic liquids: an unequal sharing of electrons between the atoms of a molecule; a three-dimensional chemical structure; a permanent, three-dimensional, and partially charged pocket within the chemical structure; a partially charged projection having a charge opposite that of the pocket and located on the side of the molecule opposite that of the pocket.

  19. Activity determination of (227)Ac and (223)Ra by means of liquid scintillation counting and determination of nuclear decay data.

    PubMed

    Kossert, Karsten; Bokeloh, Karen; Dersch, Rainer; Nähle, Ole

    2014-10-23

    The activity concentrations of solutions containing (227)Ac and (223)Ra in equilibrium with their progenies, respectively, were measured by means of liquid scintillation counting. The counting efficiencies were determined with the aid of a free parameter model. The corresponding calculations comprise the computation of several alpha, beta and beta/gamma branches. For short-lived progenies like (215)Po the counting efficiency depends on the counter dead time. Measurements were made in custom-built triple-to-double coincidence ratio (TDCR) systems and various dead-time adjustments were used. In addition, two commercial counters were used to apply the CIEMAT/NIST efficiency tracing technique using (3)H as a tracer. For the (227)Ac solution, the overall relative standard uncertainty of the activity concentration was found to be 0.93%. The dominant uncertainty components are assigned to the efficiency computation of the low-energy beta transitions of (227)Ac. We have identified a need for improved (227)Ac decay data to achieve a significant reduction in the overall uncertainty. In the case of (223)Ra, the activity concentrations were determined with relative standard uncertainties below 0.3%. Hence, PTB is prepared to provide calibration services for (223)Ra, which is an isotope of increasing interest in nuclear medicine. The TDCR measurements were also used to determine the half-life of (223)Ra. The decay was followed for about 58 days and a half-life T1/2=11.4362(50)d was obtained.

  20. 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. PMID:25299737

  1. 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.

  2. A high-sensitivity method for the measurement of 222Rn based on liquid scintillation counting of polycarbonate powder.

    PubMed

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

    2014-07-01

    This work describes a technique for the measurement of 222Rn by absorption in polycarbonate (PC) powder and liquid scintillation counting (LSC). The work is an improvement of the recently proposed method for 222Rn measurements by LSC of exposed PC grains. It is demonstrated that the use of PC powder as a 222Rn sampler improves 13.6 times the sampling efficiency and leads to 6.5 times smaller minimmal detectable activity concentrations (MDAC) compared with the PC grains used so far. For a 40-h exposure of 7.4-g PC powder to 222Rn in air, the MDAC with a RackBeta 1219 LS counter is 62 Bq m(-3) (assuming a 8-h sample counting time and 24-h background time). For the same conditions the estimated 222Rn MDAC with a Quantulus 1220 LS counter is 20 Bq m(-3). The proposed technique is suitable for radon in air and radon in soil-gas measurements.

  3. Ultrasonic study on organic liquid and binary organic liquid mixtures by using Schaaffs' collision factor theory

    NASA Astrophysics Data System (ADS)

    Lu, Yi-Gang; Dong, Yan-Wu

    2006-09-01

    Based on Schaaffs' collision factor theory (CFT) in liquids, the equations for nonlinear ultrasonic parameters in both organic liquid and binary organic liquid mixtures are deduced. The nonlinear ultrasonic parameters, including pressure coefficient, temperature coefficients of ultrasonic velocity, and nonlinear acoustic parameter B/A in both organic liquid and binary organic liquid mixtures, are evaluated for comparison with the measured results and data from other sources. The equations show that the coefficient of ultrasonic velocity and nonlinear acoustic parameter B/A are closely related to molecular interactions. These nonlinear ultrasonic parameters reflect some information of internal structure and outside status of the medium or mixtures. From the exponent of repulsive forces of the molecules, several thermodynamic parameters, pressure and temperature of the medium, the nonlinear ultrasonic parameters and ultrasonic nature of the medium can be evaluated. When evaluating and studying nonlinear acoustic parameter B/A of binary organic liquid mixtures, there is no need to know the nonlinear acoustic parameter B/A of the components. Obviously, the equation reveals the connection between the nonlinear ultrasonic nature and internal structure and outside status of the mixtures more directly and distinctly than traditional mixture law for B/A, e.g. Apfel's and Sehgal's laws for liquid binary mixtures.

  4. 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.

  5. 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.

  6. An algorithm for charge-integration, pulse-shape discrimination and estimation of neutron/photon misclassification in organic scintillators

    NASA Astrophysics Data System (ADS)

    Polack, J. K.; Flaska, M.; Enqvist, A.; Sosa, C. S.; Lawrence, C. C.; Pozzi, S. A.

    2015-09-01

    Organic scintillators are frequently used for measurements that require sensitivity to both photons and fast neutrons because of their pulse shape discrimination capabilities. In these measurement scenarios, particle identification is commonly handled using the charge-integration pulse shape discrimination method. This method works particularly well for high-energy depositions, but is prone to misclassification for relatively low-energy depositions. A novel algorithm has been developed for automatically performing charge-integration pulse shape discrimination in a consistent and repeatable manner. The algorithm is able to estimate the photon and neutron misclassification corresponding to the calculated discrimination parameters, and is capable of doing so using only the information measured by a single organic scintillator. This paper describes the algorithm and assesses its performance by comparing algorithm-estimated misclassification to values computed via a more traditional time-of-flight estimation. A single data set was processed using four different low-energy thresholds: 40, 60, 90, and 120 keVee. Overall, the results compared well between the two methods; in most cases, the algorithm-estimated values fell within the uncertainties of the TOF-estimated values.

  7. Cryogenic THGEM-GPM for the readout of scintillation light from liquid argon

    NASA Astrophysics Data System (ADS)

    Xie, Wenqing; Fu, Yidong; Li, Yulan; Li, Jin; Li, Yuanjing; Yue, Qian

    2015-02-01

    A GPM (Gaseous Photo Multiplier) based on GEMs (Gas Electron Multipliers) and THGEMs (Thick Gas Electron Multipliers) is a promising detector for VUV (Vacuum Ultra Violet) photon readouts in rare event experiments which use cryogenic two-phase detectors with detection media of Ar and Xe. A GPM based on THGEM made of PTFE (herein named PTFE-THGEM) was developed inspired by the wide use of PTFE (polytetrafluoroethene) boards as low radioactive background PCB in rare event experiments. The efficiencies of the THGEM, a CsI photocathode, and finally a GPM are presented here. At low temperature (113 K) and 1.1 atm, the quantum efficiency of the GPM for VUV photons from liquid Ar in a two-phase detector is estimated to be 8.1% and the low threshold of the detector system for initial electrons prior to multiplication is 12 using 5 N purity Ar (0.99999).

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. High-energy X-ray detection by hafnium-doped organic-inorganic hybrid scintillators prepared by sol-gel method

    SciTech Connect

    Sun, Yan; Koshimizu, Masanori Yahaba, Natsuna; Asai, Keisuke; Nishikido, Fumihiko; Kishimoto, Shunji; Haruki, Rie

    2014-04-28

    With the aim of enhancing the efficiency with which plastic scintillators detect high-energy X-rays, hafnium-doped organic-inorganic hybrid scintillators were fabricated via a sol-gel method. Transmission electron microscopy of sampled material reveals the presence of Hf{sub x}Si{sub 1−x}O{sub 2} nanoparticles, dispersed in a polymer matrix that constitutes the active material of the X-ray detector. With Hf{sub x}Si{sub 1−x}O{sub 2} nanoparticles incorporated in the polymer matrix, the absorption edge and the luminescence wavelength is shifted, which we attribute to Mie scattering. The detection efficiency for 67.4-keV X-rays in a 0.6-mm-thick piece of this material is two times better than the same thickness of a commercial plastic scintillator-NE142.

  14. Simultaneous determination of 226Ra and 210Pb in groundwater and soil samples by using the liquid scintillation counter-suspension gel method.

    PubMed

    Kim, Y J; Kim, C K; Lee, J I

    2001-02-01

    A method for the simultaneous determination of 226Ra and 210Pb in groundwater and soil samples by liquid scintillation counting was developed. Radium and lead were separated together from the samples as Ba(Ra) x PbSO4 co-precipitate, which was centrifuged and dissolved with 0.1 M EDTA solution (pH 9.0). Radium was separated as Ba(Ra)SO4 co-precipitate by adding ammonium sulfate and adjusting the pH of the solution to 4.2. Lead remaining in the solution was separated as PbSO4 precipitate by adding 9 M sulfuric acid. These Ba(Ra)SO4 and PbSO4 precipitates were purified with EDTA solution and used for measurement. To save time and to make counting samples simpler, direct counting of Ba(Ra)SO4 and PbSO4 precipitates instead of the phosphoric acid fusion method was attempted. Ba(Ra)SO4 and PbSO4 precipitates were suspended in the scintillation gel, and measured. Two liquid scintillation cocktails, Instagel XF and UltimaGold AB were used to prepare the counting samples. A mixture of water (40%), Instagel XF (40%) and UltimaGold AB (20%) formed a stable gel. Activities of 226Ra and 210Pb were calculated from the alpha spectrum of Ba(Ra)SO4 and beta spectrum of PbSO4, respectively. The long-term stability of the suspension gel was good. The analytical results of 226Ra and 210Pb in spiked groundwater samples were in good agreement with the known concentrations of 226Ra and 210Pb. The analytical values of 226Ra and 210Pb in the soil reference samples were within 11.5 and 1.6% of the relative error from the reference values, respectively.

  15. Method and apparatus for destroying organic contaminants in aqueous liquids

    DOEpatents

    Donaldson, Terrence L.; Wilson, James H.

    1993-01-01

    A method and apparatus for destroying organic contaminants, such as trichloroethylene, in aqueous liquids, such as groundwater, utilizing steam stripping integrated with biodegradation. The contaminated aqueous liquid is fed into a steam stripper causing the volatilization of essentially all of the organic contaminants and a portion of the aqueous liquid. The majority of the aqueous liquid is discharged from the steam stripper. The volatilized vapors are then condensed to the liquid phase and introduced into a bioreactor. The bioreactor contains methanotrophic microorganisms which convert the organic contaminants into mainly carbon dioxide. The effluent from the bioreactor is then recycled back to the steam stripper for further processing.

  16. Method and apparatus for destroying organic contaminants in aqueous liquids

    DOEpatents

    Donaldson, T.L.; Wilson, J.H.

    1993-09-21

    A method and apparatus for destroying organic contaminants, such as trichloroethylene, in aqueous liquids, such as groundwater, utilizing steam stripping integrated with biodegradation. The contaminated aqueous liquid is fed into a steam stripper causing the volatilization of essentially all of the organic contaminants and a portion of the aqueous liquid. The majority of the aqueous liquid is discharged from the steam stripper. The volatilized vapors are then condensed to the liquid phase and introduced into a bioreactor. The bioreactor contains methanotrophic microorganisms which convert the organic contaminants into mainly carbon dioxide. The effluent from the bioreactor is then recycled back to the steam stripper for further processing. 2 figures.

  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. Simultaneous operation of a test apparatus filled with liquid argon as bubble chamber, calorimeter and scintillation detector: Outlook and possible applications

    NASA Astrophysics Data System (ADS)

    Harigel, Gert G.

    1984-09-01

    Physics motivations for the use of argon as a new bubble chamber liquid are discussed. Results, obtained from a 2.7 1 argon detector in SPS and SC beams at CERN, comprise its track sensitivity to ionizing particles and to a laser beam in the bubble chamber mode, its use as a calorimeter through the collection of free charges in an electric field and the recording of the scintillation light produced by ionizing particles. Various interference phenomena during the simultaneous use of the hybrid properties, as well as purity requirements on the liquid are discussed. Furthermore, nitrogen and argon/nitrogen mixtures were investigated. Applications of our technique for neutrino experiments at TeV accelerators and as vertex detectors are briefly outlined. In-line holography, successfully tested in BEBC, could simplify the optical track recording and improve the resolution in very large detectors.

  19. 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)

  20. Investigation of the organic matter in inactive nuclear tank liquids

    SciTech Connect

    Schenley, R.L.; Griest, W.H.

    1990-08-01

    Environmental Protection Agency (EPA) methodology for regulatory organics fails to account for the organic matter that is suggested by total organic carbon (TOC) analysis in the Oak Ridge National Laboratory (ORNL) inactive nuclear waste-tank liquids and sludges. Identification and measurement of the total organics are needed to select appropriate waste treatment technologies. An initial investigation was made of the nature of the organics in several waste-tank liquids. This report details the analysis of ORNL wastes.

  1. 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. PMID:26856930

  2. Synergistic assembly of heavy metal clusters and luminescent organic bridging ligands in metal-organic frameworks for highly efficient X-ray scintillation.

    PubMed

    Wang, Cheng; Volotskova, Olga; Lu, Kuangda; Ahmad, Moiz; Sun, Conroy; Xing, Lei; Lin, Wenbin

    2014-04-30

    We have designed two metal-organic frameworks (MOFs) to efficiently convert X-ray to visible-light luminescence. The MOFs are constructed from M6(μ3-O)4(μ3-OH)4(carboxylate)12 (M = Hf or Zr) secondary building units (SBUs) and anthracene-based dicarboxylate bridging ligands. The high atomic number of Zr and Hf in the SBUs serves as effective X-ray antenna by absorbing X-ray photons and converting them to fast electrons through the photoelectric effect. The generated electrons then excite multiple anthracene-based emitters in the MOF through inelastic scattering, leading to efficient generation of detectable photons in the visible spectrum. The MOF materials thus serve as efficient X-ray scintillators via synergistic X-ray absorption by the metal-cluster SBUs and optical emission by the bridging ligands.

  3. Method for removing organic liquids from aqueous solutions and mixtures

    DOEpatents

    Hrubesh, Lawrence W.; Coronado, Paul R.; Dow, Jerome P.

    2004-03-23

    A method for removing organic liquids from aqueous solutions and mixtures. The method employs any porous material preferably in granular form and having small pores and a large specific surface area, that is hydrophobic so that liquid water does not readily wet its surface. In this method, organics, especially organic solvents that mix with and are more volatile than water, are separated from aqueous solution by preferentially evaporating across the liquid/solid boundary formed at the surfaces of the hydrophobic porous materials. Also, organic solvents that are immiscible with water, preferentially wet the surfaces of the hydrophobic material and are drawn within the porous materials by capillary action.

  4. Liquid crystal-templated conducting organic polymers

    DOEpatents

    Stupp, Samuel I.; Hulvat, James F.

    2004-01-20

    A method of preparing a conductive polymeric film, includes providing a liquid crystal phase comprising a plurality of hydrophobic cores, the phase on a substrate, introducing a hydrophobic component to the phase, the component a conductive polymer precursor, and applying an electric potential across the liquid crystal phase, the potential sufficient to polymerize the said precursor.

  5. [Evaluation of the reproducibility in radioactivity measurements with liquid scintillation counters--intercomparison among several presently available counters of different models (author's transl)].

    PubMed

    Iwakura, T; Yamashita, M; Yura, O; Kataoka, S; Kuze, I

    1979-07-01

    Experimental studies were carried out to evaluate the reproducibility in 3H measurements with presently available liquid scintillation counters. A set of 3H samples which have activities ranging from 10(4) to 10(7) dpm were prepared and measured repeatedly in every possible different order with six counters of different models. The results demonstrate that the measured counting rates of the samples are subjected to much greater variations than expected from counting statistics. The poor reproducibility was found to be attributed to rate dependent photomultiplier gain variations. The variations in counting rate as large as 10 per cent was observed in a particular counter. It is also found that rate dependent photomultiplier gain variations can cause the external channel ratio to shift, giving rise to error as large as 9% in the efficiency determination.

  6. Ionization and Excitation in Non-Polar Organic Liquids.

    ERIC Educational Resources Information Center

    Lipsky, Sanford

    1981-01-01

    Reviews recent advances in radiation chemistry concerning the effect of high-energy radiation on organic liquids. Discusses the general nature of excited and ionized states, pathways for decay, the effect of environmental perturbation, the behavior of an electron in a nonpolar liquid, and comparison of photochemical and radiation chemical effects.…

  7. Process for encapsulating radioactive organic liquids in a resin

    SciTech Connect

    Drake, S.S.; Filter, H.E.

    1983-05-03

    Radioactive organic liquids are converted to a form suitable for burial by the process wherein the liquid is contacted with insoluble, swellable polymer particles to form swollen gelled particles which are dispersed in an unsaturated polyester, vinyl ester resin or mixture thereof which is then cured to a solid state with the gelled particles encased therein.

  8. Process for recovering organic components from liquid streams

    DOEpatents

    Blume, Ingo; Baker, Richard W.

    1991-01-01

    A separation process for recovering organic components from liquid streams. The process is a combination of pervaporation and decantation. In cases where the liquid stream contains the organic to be separated in dissolved form, the pervaporation step is used to concentrate the organic to a point above the solubility limit, so that a two-phase permeate is formed and then decanted. In cases where the liquid stream is a two-phase mixture, the decantation step is performed first, to remove the organic product phase, and the residue from the decanter is then treated by pervaporation. The condensed permeate from the pervaporation unit is sufficiently concentrated in the organic component to be fed back to the decanter. The process can be tailored to produce only two streams: an essentially pure organic product stream suitable for reuse, and a residue stream for discharge or reuse.

  9. Nanostructure self-organization of ionic liquids

    NASA Astrophysics Data System (ADS)

    Zherenkova, L. V.; Khalatur, P. G.

    2010-06-01

    The theory of integral equations was applied to investigate the formation of structures in ionic liquids (ILs). The effect of temperature and the length of the cation tails on the structural properties of a system was studied. An intermediate type of ordering in ILs as compared with common liquids was observed. The formation of polar and nonpolar domains was revealed, with the distribution of the polar domains having the shape of a three-dimensional net coexisting with nonpolar domains. The characteristic scale of intermediate ordering was shown to increase as a power function without disturbing the shape of the distribution of polar domains as the length of the cation tails grew.

  10. Development of fusion neutron camera using organic liquid scintillator and wavelength shifting fiber

    SciTech Connect

    Inui, D.; Iguchi, T.; Watanabe, K.; Kawarabayashi, J.; Nishitani, T.

    2004-10-01

    For fusion neutron profile monitoring, we propose to use a new position sensitive fast neutron detector (PSFND). We have considered an applicability of the present PSFND to two types of fusion neutron camera; a pinhole camera and a double crystal time-of-flight camera.

  11. 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.

  12. 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.

  13. Hierarchical Organization in Liquid Crystal-in-Liquid Crystal Emulsions

    PubMed Central

    Mushenheim, Peter C.

    2014-01-01

    We report the formation and characterization of hierarchical ordering in systems comprised of micrometer-sized droplets of thermotropic nematic liquid crystals (LCs) dispersed in continuous nematic phases of a lyotropic chromonic LC (disodium cromoglycate (DSCG)). Significantly, we find the orientations of the two LC phases to be coupled, with nematic droplets of 4′-pentyl-4-cyanobiphenyl (5CB) exhibiting a bipolar configuration with an axis of symmetry aligned orthogonal to the far-field director of the DSCG phase. We determine that this coupling of orientations does not result from either anisometric LC droplet shape or interfacial ionic phenomena but rather is consistent with the influence of van der Waals interactions that arise from the anisotropic polarizabilities of nematic 5CB (Δn = + 0.18) and DSCG (Δn = − 0.02) phases. We also find that it is possible to rotate and uniformly align the nematic droplets by using a weak magnetic field (B ∼ 0.3 T). An analysis of the dynamics of relaxation of the orientations of the 5CB droplets following removal of the magnetic field reveals the DSCG and 5CB droplets to be coupled by energies of ∼104kT, consistent with a simple theoretical estimate of the influence of anisotropic van der Waals interactions. We also observed the nematic 5CB droplets to form dimers and larger assemblies mediated by the elasticity of the nematic DSCG. Overall, these results reveal that LC-in-LC emulsions define a new class of hierarchically ordered soft matter in which both thermotropic and lyotropic LCs are coupled in their ordering. PMID:25278032

  14. A Guided Inquiry Liquid/Liquid Extractions Laboratory for Introductory Organic Chemistry

    ERIC Educational Resources Information Center

    Raydo, Margaret L.; Church, Megan S.; Taylor, Zane W.; Taylor, Christopher E.; Danowitz, Amy M.

    2015-01-01

    A guided inquiry laboratory experiment for teaching liquid/liquid extractions to first semester undergraduate organic chemistry students is described. This laboratory is particularly useful for introductory students as the analytes that are separated are highly colored dye molecules. This allows students to track into which phase each analyte…

  15. 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.

  16. 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.

  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, 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 Al-27 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. (C) 2014 Elsevier B.V. All rights reserved. Keywords

  18. Neutron response characterization for an EJ299-33 plastic scintillation detector

    DOE PAGES

    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, 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 Continuousmore » spectrum neutron source, obtained via the bombardment of Al-27 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. (C) 2014 Elsevier B.V. All rights reserved. Keywords« less

  19. Neutron response characterization for an EJ299-33 plastic scintillation detector

    NASA Astrophysics Data System (ADS)

    Lawrence, Chris C.; Febbraro, Michael; Massey, Thomas N.; Flaska, Marek; Becchetti, F. D.; Pozzi, Sara A.

    2014-09-01

    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, 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. Nevertheless the EJ299 is likely to bring a modest PSD capability into a array of field applications that are not accessible to liquids or crystals.

  20. 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.

  1. 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.

  2. 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

  3. Determination of 55Fe in waste waters of the Krsko nuclear power plant measured simultaneously by liquid scintillation spectrometer (LSC) and X-ray spectrometer (XRS)

    NASA Astrophysics Data System (ADS)

    Mikelic, L.; Orescanin, V.; Lulic, S.

    2007-10-01

    This paper presents comparison of two methods for the determination of 55Fe activity of waste waters discharged from the Krsko nuclear power plant (KNPP). Research was conducted on 12 composite samples of waste water collected in the waste monitor tank (WMT) during each month as well as on Analytics, Inc. cross-check sample. Results showed that the complicated and time-consuming method proposed by the Environmental Measurements Laboratory (EML) could be successfully replaced with a simple and fast based on the extraction of 55Fe from waste water by non-specific chelating agent ammonium-pyrrolidinedithiocarbamate (APDC) at pH 4 after separation from cobalt, and activity measurement by X-ray fluorescence spectroscopy (XRS). Results obtained by the XRS method were approximately 8.6% lower than those obtained by liquid scintillation spectrometer (LSC). The mean deviation of the XRS results from the activity of cross-check sample was 2.47%, which ensures that this method is accurate enough for environmental monitoring.

  4. Determination of ⁹⁰Sr and ²¹⁰Pb in sludge samples using a LOV-MSFIA system and liquid scintillation counting.

    PubMed

    Mola, M; Avivar, J; Nieto, A; Peñalver, A; Aguilar, C; Ferrer, L; Cerdà, V; Borrull, F

    2014-04-01

    There has been increasing interest recently in the capacity of water treatment plants to concentrate and eliminate radionuclides from raw water. As the normal operation in these plants generates high quantities of sludge, which can be considered a naturally occurring radioactive material, it is important to gather information about its radiological content. Therefore, in order to determine the activity values of two radioactive beta emitters with minimal sample manipulation, an automated lab-on-valve and multisyringe flow injection system has been developed to achieve the sequential preconcentration and separation of (90)Sr and (210)Pb using an extraction chromatographic resin (Sr-spec). Activities of both isotopes were measured by liquid scintillation counting (LSC). The developed method was validated by analyzing three samples from three different intercomparison exercises and good Z-score values (between 0.1 and 1) and trueness values (between 10% and 17%) were obtained. The method was then also satisfactorily applied to sludge samples taken from a Spanish drinking water treatment plant which treats water from the Ebro River. The proposed method offers advantages over existing methods as it allows the sequential separation of both isotopes, simply by changing the elution conditions and using a semi-automated approach. Therefore, the method is less time consuming and environmentally friendly.

  5. Liquid Organic Fertilizers for Sustainable Agriculture: Nutrient Uptake of Organic versus Mineral Fertilizers in Citrus Trees

    PubMed Central

    Martínez-Alcántara, Belén; Martínez-Cuenca, Mary-Rus; Bermejo, Almudena; Legaz, Francisco; Quiñones, Ana

    2016-01-01

    The main objective of this study was to compare the performance of two liquid organic fertilizers, an animal and a plant-based fertilizer, with mineral fertilization on citrus trees. The source of the fertilizer (mineral or organic) had significant effect in the nutritional status of the organic and conventionally managed mandarins. Nutrient uptake, vegetative growth, carbohydrate synthesis and soil characteristics were analyzed. Results showed that plants fertilized with animal based liquid fertilizers exhibited higher total biomass with a more profuse development of new developing organs (leaves and fibrous roots). Liquid organic fertilization resulted in an increased uptake of macro and micronutrients compared to mineral fertilized trees. Moreover, organic fertilization positively affected the carbohydrate content (fructose, glucose and sucrose) mainly in summer flush leaves. Liquid organic fertilization also resulted in an increase of soil organic matter content. Animal-based fertilizer, due to intrinsic composition, increased total tree biomass and carbohydrate leaves content, and led to lower soil nitrate concentration and higher P and Mg exchangeable in soil extract compared to vegetal-based fertilizer. Therefore, liquid organic fertilizers could be used as an alternative to traditional mineral fertilization in drip irrigated citrus trees. PMID:27764099

  6. Use of metal organic fluors for spectral discrimination of neutrons and gammas.

    SciTech Connect

    Allendorf, Mark D.; Doty, F. Patrick; Feng, Patrick L.

    2010-09-01

    A new method for spectral shape discrimination (SSD) of fast neutrons and gamma rays has been investigated. Gammas interfere with neutron detection, making efficient discrimination necessary for practical applications. Pulse shape discrimination (PSD) in liquid organic scintillators is currently the most effective means of gamma rejection. The hazardous liquids, restrictions on volume, and the need for fast timing are drawbacks to traditional PSD scintillators. In this project we investigated harvesting excited triplet states to increase scintillation yield and provide distinct spectral signatures for gammas and neutrons. Our novel approach relies on metal-organic phosphors to convert a portion of the energy normally lost to the scintillation process into useful luminescence with sub-microsecond lifetimes. The approach enables independent control over delayed luminescence wavelength, intensity, and timing for the first time. We demonstrated that organic scintillators, including plastics, nanoporous framework materials, and oil-based liquids can be engineered for both PSD and SSD.

  7. 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.

  8. Functional liquid-crystalline assemblies: self-organized soft materials.

    PubMed

    Kato, Takashi; Mizoshita, Norihiro; Kishimoto, Kenji

    2005-12-16

    In the 21st century, soft materials will become more important as functional materials because of their dynamic nature. Although soft materials are not as highly durable as hard materials, such as metals, ceramics, and engineering plastics, they can respond well to stimuli and the environment. The introduction of order into soft materials induces new dynamic functions. Liquid crystals are ordered soft materials consisting of self-organized molecules and can potentially be used as new functional materials for electron, ion, or molecular transporting, sensory, catalytic, optical, and bio-active materials. For this functionalization, unconventional materials design is required. Herein, we describe new approaches to the functionalization of liquid crystals and show how the design of liquid crystals formed by supramolecular assembly and nano-segregation leads to the formation of a variety of new self-organized functional materials.

  9. Investigation of the reactivity of organic materials in liquid oxygen

    NASA Technical Reports Server (NTRS)

    Chamberlain, D.; Irwin, K.; Kirshen, N.; Mill, T.; Stringham, R.

    1970-01-01

    Measurements of impact-ignition sensitivity and studies of the relative reactivity of t-butoxy and t-butyl peroxy radicals toward a variety of organic compounds reveal improved methods of selection of materials for safe use in a liquid oxygen environment.

  10. Liquid organization and solvation properties at polar solid/liquid interfaces.

    PubMed

    Gobrogge, Eric A; Woods, B Lauren; Walker, Robert A

    2013-01-01

    Second order nonlinear optical spectroscopy has been employed to examine the organization of four different liquids at the hydrophilic silica/liquid interface. The liquids - cyclohexane, methylcyclohexane, 1-propanol, and 2-propanol - were chosen to isolate how intermolecular forces between the liquid and the substrate competed with steric effects to control liquid structure and solvating properties across the interfacial region. Vibrational sum frequency generation (VSFG) data showed that cyclohexane structure at the silica/liquid cyclohexane interface closely resembled the structure of a cyclohexane monolayer adsorbed to the silica/vapor interface. Methylcyclohexane, however, showed evidence of large structural reorganization between the silica/liquid and silica/monolayer/vapor interfaces. 1-Propanol at a silica/vapor interface formed a well-ordered, Langmuir-like monolayer due to strong hydrogen bonding with the surface silanols and cohesive van der Waals interactions between carbon chains. 1-Propanol at the silica/liquid interface retained the same ordered structure. In contrast, 2-propanol adopted different structures adsorbed to the solid/vapor and at the solid/ liquid interfaces. Specifically, the plane defined by 2-propanol's three carbon atoms changed orientation from being perpendicular to the surface (silica/vapor) to parallel to the surface (silica/liquid). Surface mediated liquid structure affected the solvation of adsorbed solutes. Resonance enhanced second harmonic generation (SHG) data showed that silica/alkane interfaces were significantly more polar than would be expected based on a solute's bulk solution solvatochromic behavior. Both silica/alcohol interfaces exhibited alkane-like polarity, a result that was interpreted in terms of a reduction in hydrogen bonding opportunities for adsorbed solutes.

  11. 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.

  12. 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

  13. Tetraalkylphosphonium polyoxometalate ionic liquids: novel, organic-inorganic hybrid materials.

    PubMed

    Rickert, Paul G; Antonio, Mark R; Firestone, Millicent A; Kubatko, Karrie-Ann; Szreder, Tomasz; Wishart, James F; Dietz, Mark L

    2007-05-10

    Pairing of a Keggin or Lindqvist polyoxometalate (POM) anion with an appropriate tetraalkylphosphonium cation is shown to yield the first members of a new family of ionic liquids (ILs). Detailed characterization of one of them, an ambient-temperature "liquid POM" comprising the Lindqvist salt of the trihexyl(tetradecyl) phosphonium cation, by voltammetry, viscometry, conductimetry, and thermal analysis indicates that it exhibits conductivity and viscosity comparable to those of the one previously described inorganic-organic POM-IL hybrid but with substantially improved thermal stability.

  14. Study of nuclear recoils in liquid argon with monoenergetic neutrons

    NASA Astrophysics Data System (ADS)

    Regenfus, C.; Allkofer, Y.; Amsler, C.; Creus, W.; Ferella, A.; Rochet, J.; Walter, M.

    2012-07-01

    In the framework of developments for liquid argon dark matter detectors we assembled a laboratory setup to scatter neutrons on a small liquid argon target. The neutrons are produced mono-energetically (Ekin = 2.45 MeV) by nuclear fusion in a deuterium plasma and are collimated onto a 3" liquid argon cell operating in single-phase mode (zero electric field). Organic liquid scintillators are used to tag scattered neutrons and to provide a time-of-flight measurement. The setup is designed to study light pulse shapes and scintillation yields from nuclear and electronic recoils as well as from alpha particles at working points relevant for dark matter searches. Liquid argon offers the possibility to scrutinise scintillation yields in noble liquids with respect to the population strength of the two fundamental excimer states. Here we present experimental methods and first results from recent data towards such studies.

  15. 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.

  16. Synthesis of plastic scintillation microspheres: alpha/beta discrimination.

    PubMed

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

    2014-11-01

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

  17. Dual Ionic and Organic Nature of Ionic Liquids

    PubMed Central

    Shi, Rui; Wang, Yanting

    2016-01-01

    Inherited the advantages of inorganic salts and organic solvents, ionic liquids (ILs) exhibit many superior properties allowing them promising green solvents for the future. Although it has been widely acknowledged that the unique features of ILs originate from their dual ionic and organic nature, its microscopic physical origin still remains blurry. In this work, by comparing the ion/molecule cage structures obtained from molecular dynamics simulations for seven prototypic liquids—a molten inorganic salt, four ILs, a strongly polar organic solvent, and a weakly polar organic solvent, we have revealed that the depth of the cage energy landscape characterizes the ionic nature of ILs, whereas the slope and curvature of its mimimum determine the organic nature of ILs. This finding advances our understanding of ILs and thus will help their efficient utilization as well as the systematic design of novel functionalized ILs. PMID:26782660

  18. Distinctive Nanoscale Organization of Dicationic versus Monocationic Ionic Liquids

    SciTech Connect

    Li, Song; Feng, Guang; Banuelos, Jose Leo; Rother, Gernot; Fulvio, Pasquale F; Dai, Sheng; Cummings, Peter T

    2013-01-01

    The distinctive structural organization of dicationic ionic liquids (DILs) with varying alkyl linkage chain lengths is systematically investigated using classical molecular dynamics (MD) simulations. In comparison with their counterparts, monocationic ionic liquids (MILs) with free alkyl chain, the DILs with short linkage chains exhibit almost identical structural features regardless of anion types, whereas the long-chain DILs display a relatively insignificant prepeak and low heterogeneity order parameter (HOP), which is accompanied by the less evident structural heterogeneity. Moreover, the predominant role of anion type in the structure of DILs was verified, similar to what is observed in MILs. Finally, the different nanoscale organizations in DILs and MILs are rationalized by the relatively unfavorable straight and folded chain models proposed for the nanoaggregates in DILs and the favorable micelle-like arrangement for those in MILs.

  19. Non-Carbon Dyes For Platic Scintillators- Report

    SciTech Connect

    Teprovich, J.; Colon-Mercado, H.; Gaillard, J.; Sexton, L.; Washington, A.; Ward, P.; Velten, J.

    2015-10-19

    Scintillation based detectors are desirable for many radiation detection applications (portal and border monitoring, safeguards verification, contamination detection and monitoring). The development of next generation scintillators will require improved detection sensitivity for weak gamma ray sources, and fast and thermal neutron quantification. Radiation detection of gamma and neutron sources can be accomplished with organic scintillators, however, the single crystals are difficult to grow for large area detectors and subject to cracking. Alternatives to single crystal organic scintillators are plastic scintillators (PS) which offer the ability to be shaped and scaled up to produce large sized detectors. PS is also more robust than the typical organic scintillator and are ideally suited for deployment in harsh real-world environments. PS contain a mixture of dyes to down-convert incident radiation into visible light that can be detected by a PMT. This project will evaluate the potential use of nano-carbon dyes in plastic scintillators.

  20. Energy resolution of scintillation detectors

    NASA Astrophysics Data System (ADS)

    Moszyński, M.; Syntfeld-Każuch, A.; Swiderski, L.; Grodzicka, M.; Iwanowska, J.; Sibczyński, P.; Szczęśniak, T.

    2016-01-01

    According to current knowledge, the non-proportionality of the light yield of scintillators appears to be a fundamental limitation of energy resolution. A good energy resolution is of great importance for most applications of scintillation detectors. Thus, its limitations are discussed below; which arise from the non-proportional response of scintillators to gamma rays and electrons, being of crucial importance to the intrinsic energy resolution of crystals. The important influence of Landau fluctuations and the scattering of secondary electrons (δ-rays) on intrinsic resolution is pointed out here. The study on undoped NaI and CsI at liquid nitrogen temperature with a light readout by avalanche photodiodes strongly suggests that the non-proportionality of many crystals is not their intrinsic property and may be improved by selective co-doping. Finally, several observations that have been collected in the last 15 years on the influence of the slow components of light pulses on energy resolution suggest that more complex processes are taking place in the scintillators. This was observed with CsI(Tl), CsI(Na), ZnSe(Te), and undoped NaI at liquid nitrogen temperature and, finally, for NaI(Tl) at temperatures reduced below 0 °C. A common conclusion of these observations is that the highest energy resolution, and particularly intrinsic resolution measured with the scintillators, characterized by two or more components of the light pulse decay, is obtainable when the spectrometry equipment integrates the whole light of the components. In contrast, the slow components observed in many other crystals degrade the intrinsic resolution. In the limiting case, afterglow could also be considered as a very slow component that spoils the energy resolution. The aim of this work is to summarize all of the above observations by looking for their origin.

  1. Gas-liquid chromatography in lunar organic analysis.

    NASA Technical Reports Server (NTRS)

    Gehrke, C. W.

    1972-01-01

    Gas-liquid chromatography (GLC) is a powerful and sensitive method for the separation and detection of organic compounds at nanogram levels. The primary requirement for successful analyses is that the compounds of interest must be volatile under the chromatographic conditions employed. Nonvolatile organic compounds must be converted to volatile derivatives prior to analysis. The derivatives of choice must be both amenable to chromatographic separation and be relatively stable. The condition of volatility necessitates the development of efficient derivatization reactions for important groups of compounds as amino acids, carbohydrates, nucleosides, etc. Trimethylsilylation and trifluoroacetylation represent specific areas of recent prominence. Some relevant practical aspects of GLC are discussed.

  2. 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.

  3. 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.

  4. Separation of scintillation and Cherenkov lights in linear alkyl benzene

    NASA Astrophysics Data System (ADS)

    Li, Mohan; Guo, Ziyi; Yeh, Minfang; Wang, Zhe; Chen, Shaomin

    2016-09-01

    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. The scintillation light yield was measured to be (1.01 ± 0.12) ×103 photons / MeV .

  5. Reversible Acid Gas Capture Using CO2-Binding Organic Liquids

    SciTech Connect

    Heldebrant, David J.; Koech, Phillip K.; Yonker, Clement R.; Rainbolt, James E.; Zheng, Feng

    2010-08-31

    Acid gas scrubbing technology is predominantly aqueous alkanolamine based. Of the acid gases, CO2, H2S and SO2 have been shown to be reversible, however there are serious disadvantages with corrosion and high regeneration costs. The primary scrubbing system composed of monoethanolamine is limited to 30% by weight because of the highly corrosive solution. This gravimetric limitation limits the CO2 volumetric (≤108 g/L) and gravimetric capacity (≤7 wt%) of the system. Furthermore the scrubbing system has a large energy penalty from pumping and heating the excess water required to dissolve the MEA bicarbonate salt. Considering the high specific heat of water (4 j/g-1K-1), low capacities and the high corrosion we set out to design a fully organic solvent that can chemically bind all acid gases i.e. CO2 as reversible alkylcarbonate ionic liquids or analogues thereof. Having a liquid acid gas carrier improves process economics because there is no need for excess solvent to pump and to heat. We have demonstrated illustrated in Figure 1, that CO2-binding organic liquids (CO2BOLs) have a high CO2 solubility paired with a much lower specific heat (<1.5 J/g-1K-1) than aqueous systems. CO2BOLs are a subsection of a larger class of materials known as Binding Organic Liquids (BOLs). Our BOLs have been shown to reversibly bind and release COS, CS2, and SO2, which we denote COSBOLS, CS2BOLs and SO2BOLs. Our BOLs are highly tunable and can be designed for post or pre-combustion gas capture. The design and testing of the next generation zwitterionic CO2BOLs and SO2BOLs are presented.

  6. 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.

  7. 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.

  8. 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.

  9. Group extraction of organic compounds present in liquid samples

    NASA Technical Reports Server (NTRS)

    Jahnsen, Vilhelm J. (Inventor)

    1976-01-01

    An extraction device is disclosed comprising a tube containing a substantially inert, chemically non-reactive packing material with a large surface area to volume ratio. A sample which consists of organic compounds dissolved in a liquid, is introduced into the tube. As the sample passes through the packing material it spreads over the material's large surface area to form a thin liquid film which is held on the packing material in a stationary state. A particular group or family of compounds is extractable from the sample by passing a particular solvent system consisting of a solvent and selected reagents through the packing material. The reagents cause optimum conditions to exist for the compounds of the particular family to pass through the phase boundary between the sample liquid and the solvent of the solvent system. Thus, the compounds of the particular family are separated from the sample liquid and become dissolved in the solvent of the solvent system. The particular family of compounds dissolved in the solvent, representing an extract, exits the tube together with the solvent through the tube's nozzle, while the rest of the sample remains on the packing material in a stationary state. Subsequently, a different solvent system may be passed through the packing material to extract another family of compounds from the remaining sample on the packing material.

  10. Liquid crystals for organic thin-film transistors

    PubMed Central

    Iino, Hiroaki; Usui, Takayuki; Hanna, Jun-ichi

    2015-01-01

    Crystalline thin films of organic semiconductors are a good candidate for field effect transistor (FET) materials in printed electronics. However, there are currently two main problems, which are associated with inhomogeneity and poor thermal durability of these films. Here we report that liquid crystalline materials exhibiting a highly ordered liquid crystal phase of smectic E (SmE) can solve both these problems. We design a SmE liquid crystalline material, 2-decyl-7-phenyl-[1]benzothieno[3,2-b][1]benzothiophene (Ph-BTBT-10), for FETs and synthesize it. This material provides uniform and molecularly flat polycrystalline thin films reproducibly when SmE precursor thin films are crystallized, and also exhibits high durability of films up to 200 °C. In addition, the mobility of FETs is dramatically enhanced by about one order of magnitude (over 10 cm2 V−1 s−1) after thermal annealing at 120 °C in bottom-gate-bottom-contact FETs. We anticipate the use of SmE liquid crystals in solution-processed FETs may help overcome upcoming difficulties with novel technologies for printed electronics. PMID:25857435

  11. Liquid crystals for organic thin-film transistors

    NASA Astrophysics Data System (ADS)

    Iino, Hiroaki; Usui, Takayuki; Hanna, Jun-Ichi

    2015-04-01

    Crystalline thin films of organic semiconductors are a good candidate for field effect transistor (FET) materials in printed electronics. However, there are currently two main problems, which are associated with inhomogeneity and poor thermal durability of these films. Here we report that liquid crystalline materials exhibiting a highly ordered liquid crystal phase of smectic E (SmE) can solve both these problems. We design a SmE liquid crystalline material, 2-decyl-7-phenyl-[1]benzothieno[3,2-b][1]benzothiophene (Ph-BTBT-10), for FETs and synthesize it. This material provides uniform and molecularly flat polycrystalline thin films reproducibly when SmE precursor thin films are crystallized, and also exhibits high durability of films up to 200 °C. In addition, the mobility of FETs is dramatically enhanced by about one order of magnitude (over 10 cm2 V-1 s-1) after thermal annealing at 120 °C in bottom-gate-bottom-contact FETs. We anticipate the use of SmE liquid crystals in solution-processed FETs may help overcome upcoming difficulties with novel technologies for printed electronics.

  12. Construction and testing of a neutron and gamma spectrometry system using pulse shape discrimination with an organic scintillator

    NASA Astrophysics Data System (ADS)

    Pope, Robert S.

    1993-03-01

    The goal of this thesis was to construct and test a neutron detector to measure the energy spectrum of 1 to 14-MeV neutrons in the presence of gammas. A spectrometer based on the process of pulse shape discrimination (PSD) was constructed, in which the scintillator NE-213 was used. The primary neutron/gamma sources used were 78-mCi and 4.7-Ci Pu-239Be sources, while 4.7-micro-Ci and 97.6-micro-Ci Na-22 gamma sources were used for energy calibration and additional testing of the detector. Proton recoil spectra and Compton electron spectra were unfolded with the neutron and gamma unfolding code FORIST to generate the incident neutron and gamma spectra, respectively. FORIST, which was written for a CDC computer, was modified to run on a VAX 6420. The experimental spectra were compared to those in the literature. The locations of the peaks in the Pu-239Be spectrum agreed with the literature to within 8.3%, the Pu-239Be gamma spectrum agreed to within 0.7%, while the Na-22 gamma spectrum agreed exactly. Uncertainties in the detection system and unfolding procedure are on the order of 5-10%. This thesis is intended to be a summary of the relevant literature and a user's guide to the PSD spectrometer.

  13. Self-assembly of organic films on a liquid metal

    NASA Astrophysics Data System (ADS)

    Magnussen, Olaf M.; Ocko, Benjamin M.; Deutsch, Moshe; Regan, Michael J.; Pershan, Peter S.; Abernathy, Douglas; Grübel, Gerhard; Legrand, Jean-François

    1996-11-01

    THE structure and phase behaviour of organic thin films result from the subtle interplay of intermolecular Van der Waals interactions, which promote self-assembly and long-ranged order, and the more complex interactions between the end groups of the organic chains and the substrate. The structure of molecular films of amphiphiles has been extensively studied on subphases of dielectric liquids, notably water (Langmuir mono-layers) and on solid surfaces (self-assembled monolayers, SAMs)1-4. Here we report structural studies, by synchrotron X-ray scattering, of an intermediate case: densely packed alka-nethiol films on the surface of liquid mercury. While, like SAMs, these films form strong chemical bonds to the subphase, this subphase is smooth and unstructured, as in the case of Langmuir monolayers. But unlike either of these1,2,5-7, our films have no in-plane long-range order. We suggest that the strong interaction of the thiol group with the underlying disordered liquid dominates here over the order-promoting interactions of the alkyl chains.

  14. "Liquid-liquid-solid"-type superoleophobic surfaces to pattern polymeric semiconductors towards high-quality organic field-effect transistors.

    PubMed

    Wu, Yuchen; Su, Bin; Jiang, Lei; Heeger, Alan J

    2013-12-01

    Precisely aligned organic-liquid-soluble semiconductor microwire arrays have been fabricated by "liquid-liquid-solid" type superoleophobic surfaces directed fluid drying. Aligned organic 1D micro-architectures can be built as high-quality organic field-effect transistors with high mobilities of >10 cm(2) ·V(-1) ·s(-1) and current on/off ratio of more than 10(6) . All these studies will boost the development of 1D microstructures of organic semiconductor materials for potential application in organic electronics.

  15. The aquatic impact of ionic liquids on freshwater organisms.

    PubMed

    Costa, Susana P F; Pinto, Paula C A G; Saraiva, M Lúcia M F S; Rocha, Fábio R P; Santos, Joyce R P; Monteiro, Regina T R

    2015-11-01

    Ionic liquids (ILs), also known as liquid electrolytes, are powerful solvents with a wide variety of academic and industrial applications. Bioassays with aquatic organisms constitute an effective tool for the evaluation of ILs' toxicity, as well as for the prediction and identification of possible moieties that act as toxicophores. In this work, the acute toxicity of six ILs and two commonly used organic solvents was evaluated using freshwater organisms: Daphnia magna, Raphidocelis subcapitata and Hydra attenuata. The bioassays were performed by exposing the organisms to increasing concentrations of the ILs and observing D. magna immobilization, R. subcapitata growth inhibition, and the morphological or mortality effects in H. attenuata. The results demonstrate that the tested organisms are not equally susceptible to the ILs, e.g., bmpyr [BF4] was the least toxic compound for R. subcapitata, N1,1 [N1,1,1OOH] for D. magna and emim [Tf2N] for H. attenuata. This highlights the importance of applying a battery of assays in toxicological analysis. Additionally, Hydra proved to be the most tolerant species to the tested ILs. According to their hazard rankings, the tested ILs are considered practically harmless or moderately toxic, except (Hex)3(TDec)P [Cl], which was classified as highly toxic. The ILs were revealed to be more harmful to aquatic systems than the tested organic solvents, reaffirming the need to analyze carefully the (eco)toxicological impact of these compounds. The present study provides additional data in the evaluation of the potential hazard and the impact of ILs in the environment. PMID:26151376

  16. The aquatic impact of ionic liquids on freshwater organisms.

    PubMed

    Costa, Susana P F; Pinto, Paula C A G; Saraiva, M Lúcia M F S; Rocha, Fábio R P; Santos, Joyce R P; Monteiro, Regina T R

    2015-11-01

    Ionic liquids (ILs), also known as liquid electrolytes, are powerful solvents with a wide variety of academic and industrial applications. Bioassays with aquatic organisms constitute an effective tool for the evaluation of ILs' toxicity, as well as for the prediction and identification of possible moieties that act as toxicophores. In this work, the acute toxicity of six ILs and two commonly used organic solvents was evaluated using freshwater organisms: Daphnia magna, Raphidocelis subcapitata and Hydra attenuata. The bioassays were performed by exposing the organisms to increasing concentrations of the ILs and observing D. magna immobilization, R. subcapitata growth inhibition, and the morphological or mortality effects in H. attenuata. The results demonstrate that the tested organisms are not equally susceptible to the ILs, e.g., bmpyr [BF4] was the least toxic compound for R. subcapitata, N1,1 [N1,1,1OOH] for D. magna and emim [Tf2N] for H. attenuata. This highlights the importance of applying a battery of assays in toxicological analysis. Additionally, Hydra proved to be the most tolerant species to the tested ILs. According to their hazard rankings, the tested ILs are considered practically harmless or moderately toxic, except (Hex)3(TDec)P [Cl], which was classified as highly toxic. The ILs were revealed to be more harmful to aquatic systems than the tested organic solvents, reaffirming the need to analyze carefully the (eco)toxicological impact of these compounds. The present study provides additional data in the evaluation of the potential hazard and the impact of ILs in the environment.

  17. 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.

  18. Deuterated-xylene (EJ301D): A new, improved deuterated scintillator for neutron spectroscopy

    NASA Astrophysics Data System (ADS)

    Becchetti, Fred; Torres-Isea, Ramon; Febbraro, Michael; Clarke, Shaun; di Fulvio, Angela; Pozzi, Sara

    2015-10-01

    In conjunction with Eljen Technologies (Sweetwater,TX), we have developed and evaluated a deuterated-xylene based liquid organic scintillator detector (3 in. × 3 in.) and PMT assembly. Like deuterated-benzene based scintillators such as EJ315 and NE230 the n +d recoil spectrum producing the light spectrum has distinct peaks corresponding to specific neutron energy groups. The light spectrum can then be unfolded to produce neutron energy spectra including fission spectra without the need for time-of-flight. This results in a large over-all detection efficiency for such detectors as they can be used in arrays covering a large angular range, close to the neutron source and do not require a pulsed or gated source. In addition, the new EJ301D scintillator has a lower neutron energy threshold for improved PSD, which is important in many low-energy measurements. More importantly this scintillator has a much safer flash point than benzene-based scintillators making it better suited for many applications including field applications in nuclear security and non-proliferation. Work supported in part by US NSF and by the Consortium for Verification Technology under Department of Energy National Nuclear Security Administration Award Number DE-NA0002534.

  19. Comparison of capillary pressure relationships of organic liquid water systems containing an organic acid or base

    NASA Astrophysics Data System (ADS)

    Lord, D. L.; Demond, A. H.; Hayes, K. F.

    2005-04-01

    The presence of surface-active solutes such as organic acids and bases may have a profound influence on the transport of organic liquid contaminants through their impact on the constitutive relationship of capillary pressure vs. saturation. This relationship is a function of the interfacial tension and wettability of the system, which, in turn, depend on the pH and the concentration of organic acids and bases that are present. This study examines the impact of pH and the concentration on the interfacial tension, contact angle, and capillary pressure of systems consisting of tetrachloroethylene, water, and quartz containing either octanoic acid or dodecylamine. In general, the ionic form of the solute tended to remain in the aqueous phase and reduced the capillary pressure through its impact on the interfacial tension and contact angle; on the other hand, the neutral form of the solute partitioned into the organic liquid phase and had a lesser impact on the capillary pressure for the same total mass of solute. A comparison of these data with data generated in previous research in similar systems where o-xylene was the organic liquid showed that the trends are analogous. Thus, the behavior of these two solvent systems seems to be driven primarily by the aqueous phase speciation of the solute, and the differences between the capillary pressure relationships for the two systems could be attributed to the pure system interfacial tension.

  20. Acid Gas Capture Using CO2-Binding Organic Liquids

    SciTech Connect

    Heldebrant, David J.; Koech, Phillip K.; Rainbolt, James E.; Zheng, Feng

    2010-11-10

    Current chemical CO2 scrubbing technology is primarily aqueous alkanolamine based. These systems rapidly bind CO2 (forming water-soluble carbamate and bicarbonate salts) however, the process has serious disadvantages. The concentration of monoethanolamine rarely exceeds 30 wt % due to the corrosive nature of the solution, and this reduces the maximum CO2 volumetric (≤108 g/L) and gravimetric capacity (≤7 wt%) of the CO2 scrubber. The ≤30 wt % loading of ethanolamine also means that a large excess of water must be pumped and heated during CO2 capture and release, and this greatly increases the energy requirements especially considering the high specific heat of water (4 j/g-1K-1). Our approach is to switch to organic systems that chemically bind CO2 as liquid alkylcarbonate salts. Our CO2-binding organic liquids have higher CO2 solubility, lower specific heats, potential for less corrosion and lower binding energies for CO2 than aqueous systems. CO2BOLs also reversibly bind and release mixed sulfur oxides. Furthermore the CO2BOL system can be direct solvent replacements for any solvent based CO2 capture systems because they are commercially available reagents and because they are fluids they would not require extensive process re-engineering.

  1. 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.

  2. Shifting scintillator neutron detector

    SciTech Connect

    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.

  3. 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.

  4. 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.

  5. Poly(ionic liquid) superabsorbent for polar organic solvents.

    PubMed

    Horne, W Jeffrey; Andrews, Mary A; Terrill, Kelsey L; Hayward, Spenser S; Marshall, Jeannie; Belmore, Kenneth A; Shannon, Matthew S; Bara, Jason E

    2015-05-01

    A simple, polymerized ionic liquid (poly(IL)) based on methylimidazolium cations tethered to a polystyrene backbone exhibits superabsorbent behavior toward polar organic solvents, most notably propylene carbonate (PC) and dimethyl sulfoxide (DMSO), wherein the poly(IL) was observed to swell more than 390 and 200 times (w/w) its original mass, yet absorbs negligible quantities of water, hexanes, and other solvents, many of which were miscible with the IL monomer. Although solubility parameters and dielectric constants are typically used to rationalize such behaviors, we find that poly(IL)-solvent compatibility is most clearly correlated to solvent dipole moment. Poly(IL) superabsorbency is not reliant upon the addition of a cross-linking agent. PMID:25893981

  6. Removal of organic impurities from liquid carbon dioxide

    NASA Astrophysics Data System (ADS)

    Zito, Richard R.

    2002-09-01

    The use of a high velocity stream of carbon dioxide snowflakes to clean large optics is well known, and has gained widespread acceptance in the astronomical community as a telescope maintenance technique. Ultimately, however, the success of carbon dioxide snow cleaning depends on the availability of high purity carbon dioxide. The higher the purity of the carbon dioxide, the longer will be the time interval between required mirror washings. The highest grades of commercially produced liquid carbon dioxide are often not available in the more remote regions of the world - such as where major astronomical observatories are often located. Furthermore, the purity of even the highest grades of carbon dioxide are only nominal, and wide variations are known to occur from tank to tank. Occasionally, visible deposits of organic impurities are left behind during cleaning with carbon dioxide that is believed to be 99.999% pure. A zeolite molecular sieve based filtration system has proven to be very effective in removing these organic impurities. A zeolite is a complex alumino-silicate. One example has an empirical formula of Na2O(Al2O3)(SiO2)2yH2O, where y=0 to 8. The zeolites have an open crystal structure and are capable of trapping impurities like 8-methylheptadecane (an oil) and 2,6-octadine-1-ol,3,7- dimethyl-,(E)- (a fatty acid). In fact, a zeolite can trap 29.5% of its own weight in SAE 20 lubricant at 25 degree(s)C. After filtration of liquid CO2 through zeolites, the concentration of measured impurities was below the detection limit for state-of-the-art gas chromatography systems.

  7. Catalytic conversion of nonfood woody biomass solids to organic liquids.

    PubMed

    Barta, Katalin; Ford, Peter C

    2014-05-20

    This Account outlines recent efforts in our laboratories addressing a fundamental challenge of sustainability chemistry, the effective utilization of biomass for production of chemicals and fuels. Efficient methods for converting renewable biomass solids to chemicals and liquid fuels would reduce society's dependence on nonrenewable petroleum resources while easing the atmospheric carbon dioxide burden. The major nonfood component of biomass is lignocellulose, a matrix of the biopolymers cellulose, hemicellulose, and lignin. New approaches are needed to effect facile conversion of lignocellulose solids to liquid fuels and to other chemical precursors without the formation of intractable side products and with sufficient specificity to give economically sustainable product streams. We have devised a novel catalytic system whereby the renewable feedstocks cellulose, organosolv lignin, and even lignocellulose composites such as sawdust are transformed into organic liquids. The reaction medium is supercritical methanol (sc-MeOH), while the catalyst is a copper-doped porous metal oxide (PMO) prepared from inexpensive, Earth-abundant starting materials. This transformation occurs in a single stage reactor operating at 300-320 °C and 160-220 bar. The reducing equivalents for these transformations are derived by the reforming of MeOH (to H2 and CO), which thereby serves as a "liquid syngas" in the present case. Water generated by deoxygenation processes is quickly removed by the water-gas shift reaction. The Cu-doped PMO serves multiple purposes, catalyzing substrate hydrogenolysis and hydrogenation as well as the methanol reforming and shift reactions. This one-pot "UCSB process" is quantitative, giving little or no biochar residual. Provided is an overview of these catalysis studies beginning with reactions of the model compound dihydrobenzofuran that help define the key processes occurring. The initial step is phenyl-ether bond hydrogenolysis, and this is followed by

  8. Catalytic conversion of nonfood woody biomass solids to organic liquids.

    PubMed

    Barta, Katalin; Ford, Peter C

    2014-05-20

    This Account outlines recent efforts in our laboratories addressing a fundamental challenge of sustainability chemistry, the effective utilization of biomass for production of chemicals and fuels. Efficient methods for converting renewable biomass solids to chemicals and liquid fuels would reduce society's dependence on nonrenewable petroleum resources while easing the atmospheric carbon dioxide burden. The major nonfood component of biomass is lignocellulose, a matrix of the biopolymers cellulose, hemicellulose, and lignin. New approaches are needed to effect facile conversion of lignocellulose solids to liquid fuels and to other chemical precursors without the formation of intractable side products and with sufficient specificity to give economically sustainable product streams. We have devised a novel catalytic system whereby the renewable feedstocks cellulose, organosolv lignin, and even lignocellulose composites such as sawdust are transformed into organic liquids. The reaction medium is supercritical methanol (sc-MeOH), while the catalyst is a copper-doped porous metal oxide (PMO) prepared from inexpensive, Earth-abundant starting materials. This transformation occurs in a single stage reactor operating at 300-320 °C and 160-220 bar. The reducing equivalents for these transformations are derived by the reforming of MeOH (to H2 and CO), which thereby serves as a "liquid syngas" in the present case. Water generated by deoxygenation processes is quickly removed by the water-gas shift reaction. The Cu-doped PMO serves multiple purposes, catalyzing substrate hydrogenolysis and hydrogenation as well as the methanol reforming and shift reactions. This one-pot "UCSB process" is quantitative, giving little or no biochar residual. Provided is an overview of these catalysis studies beginning with reactions of the model compound dihydrobenzofuran that help define the key processes occurring. The initial step is phenyl-ether bond hydrogenolysis, and this is followed by

  9. Reactive Uptake of Ammonia and Formation of Organic Nitrogen Species for Non-Liquid/Liquid Secondary Organic Material

    NASA Astrophysics Data System (ADS)

    Martin, S. T.; Li, Y.; Liu, P.

    2015-12-01

    Formation of ammonium and organic nitrogen (ON) species was studied for secondary organic material (SOM) of variable viscosity, ranging from non-liquid to liquid physical states. The SOM was produced as particles of 50 to 150 nm in diameter in aerosol form from six precursors, including three terpenoid and three aromatic species. The viscosity of the hygroscopic SOM was adjusted by exposure to relative humidity (RH) from <5% to >90% RH in steps of 10% at 293 ± 2 K. The aerosol was subsequently exposed to 5 ppm NH3 for mean reaction times of 30, 370, or 5230 s. Ammonium and ON were characterized by high-resolution time-of-flight aerosol mass spectrometry (HR-ToF-AMS). The ammonium-to-organic ratio of mass concentrations (MNH4/MOrg) in the particles increased monotonically from <5% RH to a limiting value at a threshold RH, implicating a switchover in the reaction kinetics from a system limited by diffusivity within the SOM for low RH to one limited by other factors, such as saturated uptake, at higher RH. Formation of ON was observed for aromatic-derived SOMs, but not significant for terpenoid-derived SOMs. For aromatic-derived SOMs, the ON-to-organic ratio of mass concentrations (MON/MOrg) was negligible for RH <20%, increased monotonically from 20% to 60% RH, and stayed constant for RH >60%. The threshold RH for the switchover from kinetically controlled regime to a non-kinetically-controlled one was thus different between formation of ammonium and ON. This difference suggests that water may play a role in the slow reactions of ON formation as a reactant or a catalyst, in addition to affecting the reactant diffusion as in the fast reaction of ammonium formation. The implication is that formation of ammonium salts and organic nitrogen species by certain SOMs should be treated separately in chemical transport models to reflect the different roles of water that may affect the phase state of the SOMs or may act as a reactant or a catalyst.

  10. Investigation of the organic matter in inactive nuclear tank liquids. Environmental Restoration Program

    SciTech Connect

    Schenley, R.L.; Griest, W.H.

    1990-08-01

    Environmental Protection Agency (EPA) methodology for regulatory organics fails to account for the organic matter that is suggested by total organic carbon (TOC) analysis in the Oak Ridge National Laboratory (ORNL) inactive nuclear waste-tank liquids and sludges. Identification and measurement of the total organics are needed to select appropriate waste treatment technologies. An initial investigation was made of the nature of the organics in several waste-tank liquids. This report details the analysis of ORNL wastes.

  11. Azobenzene-based organic salts with ionic liquid and liquid crystalline properties

    SciTech Connect

    Stappert, Kathrin; Muthmann, Johanna; Spielberg, Eike T.; Mudring, Anja -Verena

    2015-07-23

    Two sets of new azobenzene-based bromide salts are synthesized, and their thermal photochromic properties are studied. Both sets are based on the imidazolium cation. The first set (1) features a symmetric biscation where two imidazolium head groups (Im) with different alkyl chains (Cn) are connected to a central azobenzene unit (Azo): [Azo(C1-Im-Cn)2]; n = 6, 8, 10, 12, 14. The other one contains an n-alkyl-imidazolium cation (Cn-Im) bearing a terminal azobenzene unit (C1-Azo) substituted with an alkoxy chain (O-Cm) of either two (2) or six (3) carbon atoms: [C1-Azo-O-Cm-Im-Cn]; m = 2, n = 8, 10, 12 and m = 6, n = 8, 10, 12, 14, 16. For both cation classes, the influence of alkyl chains of varying length on the thermal phase behavior was investigated by differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). For five compounds (Azo(-C1-Im-C12)2 (1d), Azo(-C1-Im-C12)2 (1e), C1-Azo-O-C2-Im-C10 (2b), C1-Azo-O-C2-Im-C12 (2c), and C1-Azo-O-C6-Im-C16 (3e)), the formation of a liquid crystalline phase was observed. The biscationic salts (1) are all comparatively high melting organic salts (180–240 °C), and only the two representatives with long alkylchains (C12 and C14) exhibit liquid crystallinity. The monocationic salts with an O–C2 bridge (2) melt between 140 and 170 °C depending on the alkyl chain length, but from an alkyl chain of 10 and more carbon atoms on they form a smectic A liquid crystalline phase. The representatives of the third set with a O–C6 bridge qualify as ionic liquids with melting points less than 100 °C. However, only the representative with a hexadecyl chain forms a liquid crystalline phase. Representative single crystals for all sets of cations could be grown that allowed for single crystal structure analysis. Together with small-angle X-ray scattering experiments they allow for a more detailed understanding of the thermal properties. As a result, through irradiation with UV

  12. Azobenzene-based organic salts with ionic liquid and liquid crystalline properties

    DOE PAGES

    Stappert, Kathrin; Muthmann, Johanna; Spielberg, Eike T.; Mudring, Anja -Verena

    2015-07-23

    Two sets of new azobenzene-based bromide salts are synthesized, and their thermal photochromic properties are studied. Both sets are based on the imidazolium cation. The first set (1) features a symmetric biscation where two imidazolium head groups (Im) with different alkyl chains (Cn) are connected to a central azobenzene unit (Azo): [Azo(C1-Im-Cn)2]; n = 6, 8, 10, 12, 14. The other one contains an n-alkyl-imidazolium cation (Cn-Im) bearing a terminal azobenzene unit (C1-Azo) substituted with an alkoxy chain (O-Cm) of either two (2) or six (3) carbon atoms: [C1-Azo-O-Cm-Im-Cn]; m = 2, n = 8, 10, 12 and m =more » 6, n = 8, 10, 12, 14, 16. For both cation classes, the influence of alkyl chains of varying length on the thermal phase behavior was investigated by differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). For five compounds (Azo(-C1-Im-C12)2 (1d), Azo(-C1-Im-C12)2 (1e), C1-Azo-O-C2-Im-C10 (2b), C1-Azo-O-C2-Im-C12 (2c), and C1-Azo-O-C6-Im-C16 (3e)), the formation of a liquid crystalline phase was observed. The biscationic salts (1) are all comparatively high melting organic salts (180–240 °C), and only the two representatives with long alkylchains (C12 and C14) exhibit liquid crystallinity. The monocationic salts with an O–C2 bridge (2) melt between 140 and 170 °C depending on the alkyl chain length, but from an alkyl chain of 10 and more carbon atoms on they form a smectic A liquid crystalline phase. The representatives of the third set with a O–C6 bridge qualify as ionic liquids with melting points less than 100 °C. However, only the representative with a hexadecyl chain forms a liquid crystalline phase. Representative single crystals for all sets of cations could be grown that allowed for single crystal structure analysis. Together with small-angle X-ray scattering experiments they allow for a more detailed understanding of the thermal properties. As a result, through irradiation with UV-light (320–366 nm) all

  13. Temperature dependence of alpha-induced scintillation in the 1,1,4,4-tetraphenyl-1,3-butadiene wavelength shifter

    NASA Astrophysics Data System (ADS)

    Veloce, L. M.; Kuźniak, M.; Di Stefano, P. C. F.; Noble, A. J.; Boulay, M. G.; Nadeau, P.; Pollmann, T.; Clark, M.; Piquemal, M.; Schreiner, K.

    2016-06-01

    Liquid noble based particle detectors often use the organic wavelength shifter 1,1,4,4-tetraphenyl-1,3-butadiene (TPB) which shifts UV scintillation light to the visible regime, facilitating its detection, but which also can scintillate on its own. Dark matter searches based on this type of detector commonly rely on pulse-shape discrimination (PSD) for background mitigation. Alpha-induced scintillation therefore represents a possible background source in dark matter searches. The timing characteristics of this scintillation determine whether this background can be mitigated through PSD. We have therefore characterized the pulse shape and light yield of alpha induced TPB scintillation at temperatures ranging from 300 K down to 4 K, with special attention given to liquid noble gas temperatures. We find that the pulse shapes and light yield depend strongly on temperature. In addition, the significant contribution of long time constants above ~50 K provides an avenue for discrimination between alpha decay events in TPB and nuclear-recoil events in noble liquid detectors.

  14. Organic electrical double layer transistors gated with ionic liquids

    NASA Astrophysics Data System (ADS)

    Xie, Wei; Frisbie, C. Daniel

    2011-03-01

    Transport in organic semiconductors gated with several types of ionic liquids has been systematically studied at charge densities larger than 1013 cm-2 . We observe a pronounced maximum in channel conductance for both p-type and n-type organic single crystals which is attributed to carrier localization at the semiconductor-electrolyte interface. Carrier mobility, as well as charge density and dielectric capacitance are determined through displacement current measurement and capacitance-voltage measurement. By using a larger-sized and spherical anion, tris(pentafluoroethyl)trifluorophosphate (FAP), effective carrier mobility in rubrene can be enhanced substantially up to 3.2 cm2 V-1 s -1 . Efforts have been made to maximize the charge density in rubrene single crystals, and at low temperature when higher gate bias can be applied, charge density can more than double the amount of that at room temperature, reaching 8*1013 cm-2 holes (0.4 holes per rubrene molecule). NSF MRSEC program at the University of Minnesota.

  15. Incineration of radioactive organic liquid wastes by underwater thermal plasma

    NASA Astrophysics Data System (ADS)

    Mabrouk, M.; Lemont, F.; Baronnet, J. M.

    2012-12-01

    This work deals with incineration of radioactive organic liquid wastes using an oxygen thermal plasma jet, submerged under water. The results presented here are focused on incineration of three different wastes: a mixture of tributylphosphate (TBP) and dodecane, a perfluoropolyether oil (PFPE) and trichloroethylene (TCE). To evaluate the plutonium behavior in used TBP/dodecane incineration, zirconium is used as a surrogate of plutonium; the method to enrich TBP/dodecane mixture in zirconium is detailed. Experimental set-up is described. During a trial run, CO2 and CO contents in the exhaust gas are continuously measured; samples, periodically taken from the solution, are analyzed by appropriate chemical methods: contents in total organic carbon (COT), phosphorus, fluoride and nitrates are measured. Condensed residues are characterized by RX diffraction and SEM with EDS. Process efficiency, during tests with a few L/h of separated or mixed wastes, is given by mineralization rate which is better than 99.9 % for feed rate up to 4 L/h. Trapping rate is also better than 99 % for phosphorous as for fluorine and chlorine. Those trials, with long duration, have shown that there is no corrosion problems, also the hydrogen chloride and fluoride have been neutralized by an aqueous solution of potassium carbonate.

  16. Discotic liquid crystals: a new generation of organic semiconductors.

    PubMed

    Sergeyev, Sergey; Pisula, Wojciech; Geerts, Yves Henri

    2007-12-01

    Discotic (disc-like) molecules typically comprising a rigid aromatic core and flexible peripheral chains have been attracting growing interest because of their fundamental importance as model systems for the study of charge and energy transport and due to the possibilities of their application in organic electronic devices. This critical review covers various aspects of recent research on discotic liquid crystals, in particular, molecular design concepts, supramolecular structure, processing into ordered thin films and fabrication of electronic devices. The chemical structure of the conjugated core of discotic molecules governs, to a large extent, their intramolecular electronic properties. Variation of the peripheral flexible chains and of the aromatic core is decisive for the tuning of self-assembly in solution and in bulk. Supramolecular organization of discotic molecules can be effectively controlled by the choice of the processing methods. In particular, approaches to obtain suitable macroscopic orientations of columnar superstructures on surfaces, that is, planar uniaxial or homeotropic alignment, are discussed together with appropriate processing techniques. Finally, an overview of charge transport in discotic materials and their application in optoelectronic devices is given. PMID:17982517

  17. Improvement of natural pastures using liquid organic fertilizers

    NASA Astrophysics Data System (ADS)

    Ghambashidze, Giorgi; Gabedava, Giorgi; Abuladze, Paata

    2016-04-01

    Nowadays natural pastures remains the main source to supply livestock with fresh feed material in Georgia. Due to that common pasturelands are under continues grazing pressure and normally no measures are taken in order to improve pasture productivity and to protect soil from erosion. Unregulated stocking rate leads to overutilization of natural pastures causing reduction in productivity and soil fertility. It is especially evident in arid regions, where bare soil after removal of vegetation dries out and is subject to wind erosion. In many areas even with regulated stocking rate plant available soil nutrient pool is already diminished and vegetation cannot be recovered easily after grazing. Therefore it is essential to improve soil fertility, which provide adequate amount of nutrients to plants to regenerate. Ongoing study aims to compare effect of different types of organic fertilizers on natural pastures in combination with pasture rotation scheme in order to maintain soil fertility and prepare the basis for its gradual improvement. Initial results shows positive impact of liquid organic fertilizers which increased aboveground biomass production by 200-300 kg per hectare.

  18. Self-organized discotic liquid crystals for high-efficiency organic photovoltaics.

    PubMed

    Schmidt-Mende, L; Fechtenkötter, A; Müllen, K; Moons, E; Friend, R H; MacKenzie, J D

    2001-08-10

    Self-organization of liquid crystalline and crystalline-conjugated materials has been used to create, directly from solution, thin films with structures optimized for use in photodiodes. The discotic liquid crystal hexa-peri-hexabenzocoronene was used in combination with a perylene dye to produce thin films with vertically segregated perylene and hexabenzocoronene, with large interfacial surface area. When incorporated into diode structures, these films show photovoltaic response with external quantum efficiencies of more than 34 percent near 490 nanometers. These efficiencies result from efficient photoinduced charge transfer between the hexabenzocoronene and perylene, as well as from effective transport of charges through vertically segregated perylene and hexabenzocoronene pi systems. This development demonstrates that complex structures can be engineered from novel materials by means of simple solution-processing steps and may enable inexpensive, high-performance, thin-film photovoltaic technology.

  19. Material degradation of liquid organic semiconductors analyzed by nuclear magnetic resonance spectroscopy

    SciTech Connect

    Fukushima, Tatsuya; Yamamoto, Junichi; Fukuchi, Masashi; Kaji, Hironori; Hirata, Shuzo; Jung, Heo Hyo; Adachi, Chihaya; Hirata, Osamu; Shibano, Yuki

    2015-08-15

    Liquid organic light-emitting diodes (liquid OLEDs) are unique devices consisting only of liquid organic semiconductors in the active layer, and the device performances have been investigated recently. However, the device degradation, especially, the origin has been unknown. In this study, we show that material degradation occurs in liquid OLEDs, whose active layer is composed of carbazole with an ethylene glycol chain. Nuclear magnetic resonance (NMR) experiments clearly exhibit that the dimerization reaction of carbazole moiety occurs in the liquid OLEDs during driving the devices. In contrast, cleavages of the ethylene glycol chain are not detected within experimental error. The dimerization reaction is considered to be related to the device degradation.

  20. Determination of optimal ionic liquid for organic single-crystal field-effect transistors

    NASA Astrophysics Data System (ADS)

    Ono, S.; Miwa, K.; Seki, S.

    2016-02-01

    We investigate organic single-crystal field-effect transistors with various ionic liquids as gate dielectric. We find that the mobility of the field-effect transistors for both p-type and n-type organic semiconductors increases with decreasing total capacitance of the ionic liquid. However, it does not depend on the ion species at the interface between the organic semiconductor and the ionic liquid. By choosing an appropriate ionic liquid, a high carrier mobility of 12.4 cm2/V s in rubrene single crystals (p-type) and 0.13 cm2/V s in 7.7.8.8-Tetracyanoquinodimethane single crystals (n-type) are achieved. This study clarifies the influence of ionic liquids on the device performance of organic field-effect transistors and shows a way to maximize carrier mobility at the solid/liquid interface.

  1. Multiwalled carbon nanotubes sensor for organic liquid detection at room temperature

    NASA Astrophysics Data System (ADS)

    Chaudhary, Deepti; Khare, Neeraj; Vankar, V. D.

    2016-04-01

    We have explored the possibility of using multiwalled carbon nanotubes (MWCNTs) as room temperature chemical sensor for the detection of organic liquids such as ethanol, propanol, methanol and toluene. MWCNTs were synthesized by thermal chemical vapor deposition (TCVD) technique. The interdigitated electrodes were fabricated by conventional photolithography technique. The sensor was fabricated by drop depositing MWCNT suspension onto the interdigitated electrodes. The sensing properties of MWCNTs sensor was studied for organic liquids detection. The resistance of sensor was found to increase upon exposure to these liquids. Sensor shows good reversibility and fast response at room temperature. Charge transfer between the organic liquid and sensing element is the dominant sensing mechanism.

  2. Potential of Organic Matrix Composites for Liquid Oxygen Tank

    NASA Technical Reports Server (NTRS)

    Davis, Samuel E.; Herald, Stephen D.; Stolzfus, Joel M.; Engel, Carl D.; Bohlen, James W.; Palm, Tod; Robinson, Michael J.

    2005-01-01

    Composite materials are being considered for the tankage of cryogenic propellants in access to space because of potentially lower structural weights. A major hurdle for composites is an inherent concern about the safety of using flammable structural materials in contact with liquid and gaseous oxygen. A hazards analysis approach addresses a series of specific concerns that must be addressed based upon test data. Under the 2nd Generation Reusable Launch Vehicle contracts, testing was begun for a variety of organic matrix composite materials both to aid in the selection of materials and to provide needed test data to support hazards analyses. The work has continued at NASA MSFC and the NASA WSTF to provide information on the potential for using composite materials in oxygen systems. Appropriate methods for oxygen compatibility testing of structural materials and data for a range of composite materials from impact, friction, flammability and electrostatic discharge testing are presented. Remaining concerns and conclusions about composite tank structures, and recommendations for additional testing are discussed. Requirements for system specific hazards analysis are identified.

  3. Development of polyatomic ion beam system using liquid organic materials

    NASA Astrophysics Data System (ADS)

    Takaoka, G. H.; Nishida, Y.; Yamamoto, T.; Kawashita, M.

    2005-08-01

    We have developed a new type of polyatomic ion beam system using liquid organic materials such as octane and ethanol, which consists of a capillary type of nozzle, an ionizer, a mass-separator and a substrate holder. Ion current extracted after ionization was 430 μA for octane and 200 μA for ethanol, respectively. The mass-analysis was realized using a compact E × B mass filter, and the mass-analyzed ion beams were transferred toward the substrate. The ion current density at the substrate was a few μA/cm2 for the mass-separated ion species. Interactions of polyatomic ion beams with silicon (Si) surfaces were investigated by utilizing the ellipsometry measurement. It was found that the damaged layer thickness irradiated by the polyatomic ions with a mass number of about 40 was smaller than that by Ar ion irradiation at the same incident energy and ion fluence. The result indicated that the rupture of polyatomic ions occurred upon its impact on the Si surface with an incident energy larger than a few keV. In addition, the chemical modification of Si surfaces such as wettability could be achieved by adjusting the incident energy for the ethanol ions, which included all the fragment ions.

  4. Liquid organic hydrogen carriers: surface science studies of carbazole derivatives.

    PubMed

    Papp, Christian; Wasserscheid, Peter; Libuda, Jörg; Steinrück, Hans-Peter

    2014-10-01

    We review recent results towards a molecular understanding of the adsorption and dehydrogenation of carbazole-derived liquid organic hydrogen carriers on platinum and palladium single crystals and on Al2 O3 -supported Pt and Pd nanoparticles. By combining synchrotron-based high-resolution X-ray photoelectron spectroscopy, infrared reflection-absorption spectroscopy, advanced molecular beam methods and temperature-programmed desorption spectroscopy, detailed insights into the reaction mechanism are obtained. On Pt(111), dehydrogenation of perhydro-N-ethylcarbazole, H12 -NEC, starts with activation of the hydrogen atoms at the pyrrole unit, yielding H8 -NEC as the first stable reaction intermediate at ∼340 K, followed by further dehydrogenation to NEC at ∼380 K. Above 390 K, dealkylation starts, yielding carbazole as an undesired byproduct. On small supported Pt particles, the dealkylation sets in at lower temperatures, due to the higher reactivity of low-coordinated sites, while on larger particles with (111) facets a reactivity as on the flat surface is observed. Carbazole derivatives with ethyl, propyl and butyl chains show an overall very similar reactivity, both on Pt(111) and on Pt nanoparticles. When comparing the dealkylation behavior of H12 -NEC on Pt(111) and Pt nanoparticles to that on Pd(111) and Pd nanoparticles, we find a higher reactivity for the Pd systems.

  5. Tertiary phase diagram of cellulose, ionic liquid and organic solvent

    NASA Astrophysics Data System (ADS)

    Zhang, Xin; Henderson, Doug; Tyagi, Madhusudan; Mao, Yimin; Briber, Robert M.; Wang, Howard

    Cellulose is the most abundant natural polymer on earth, and widely used in products from clothing to paper. Fundamental understanding of molecular solutions of cellulose is the key to realize advanced technologies beyond cellulose fibers. It has been reported that certain ionic liquid/organic solvent mixtures dissolve cellulose. In this study, the tertiary phase diagram of microcrystalline cellulose, 1-Ethyl-3-methylimidazolium acetate (EMIMAc), and dimethylformamide (DMF) mixtures has been determined using optical cloud point method and small angle neutron scattering (SANS). Data indicate that a molar ratio of EMIMAc to cellulose repeating unit equal or greater than 3 is necessary but not sufficient in forming one-phase homogeneous solutions. A miscibility gap exists in the dilute regime, where a minimum of 5 mol% of EMIM Ac in DMF is needed to form homogenous solutions. SANS show that cellulose chains adopt Gaussian-like conformation in homogenous solutions. The solutions exhibit the characteristics of upper critical solution temperature. Clustering of cellulose chains occurs at low EMIMAc/DMF or EMIMAc/cellulose ratio, or at low temperatures. The mechanism of cellulose dissolution in tertiary mixture is discussed.

  6. Electronic functionalization of solid-to-liquid interfaces between organic semiconductors and ionic liquids: Realization of very high performance organic single-crystal transistors

    NASA Astrophysics Data System (ADS)

    Uemura, T.; Hirahara, R.; Tominari, Y.; Ono, S.; Seki, S.; Takeya, J.

    2008-12-01

    High-performance electronic function of current amplification is realized with the use of solid-to-liquid interfaces between organic semiconductors and ionic liquid. To hold in place the ionic liquid of 1-ethyl-3-methyl-imidazolium bis(trifluoromethanesulfonyl)imide known for low viscosity and high ionic conductivity, an elastomeric well structure is fabricated with polydimethylsiloxane on which organic single crystals of rubrene are electrostatically attached. As the result of rapid formation of electric double layers in the ionic liquid interfacing, the high-mobility organic semiconductor crystals' fast-switching transistor function is demonstrated with the application of gate voltage, realizing the highest sheet transconductance, namely, amplifying performance, ever achieved.

  7. Investigation of the Extinguishing Features for Liquid Fuels and Organic Flammable Liquids Atomized by a Water Flow

    NASA Astrophysics Data System (ADS)

    Voytkov, Ivan V.; Zabelin, Maksim V.; Vysokomornaya, Olga V.

    2016-02-01

    The processes of heat and mass transfer were investigated experimentally while moving and evaporating the atomized water flow in high-temperature combustion products of typical liquid fuels and organic flammable liquids: gasoline, kerosene, acetone, crude oil, industrial alcohol. We determined typical periods of liquid extinguishing by an atomized water flow of various dispersability. Data of the discharge of extinguishing medium corresponding to various parameters of atomization and duration of using the atomization devices was presented. It is shown that Um≈3.5 m/s is a minimal outflow velocity of droplets during moving while passing the distance of 1m in the high-temperature gas medium to stop the combustion of organic liquids.

  8. Surface Tension of Organic Liquids Using the OPLS/AA Force Field.

    PubMed

    Zubillaga, Rafael A; Labastida, Ariana; Cruz, Bibiana; Martínez, Juan Carlos; Sánchez, Enrique; Alejandre, José

    2013-03-12

    Molecular dynamics simulations are performed to obtain the surface tension of 61 organic liquids using the OPLS/AA (all-atom optimized potential for liquid simulations). The force field parameters are the same as those recently used (Caleman et al. J. Chem. Theory Comput.2012, 8, 61) to determine several thermodynamic properties of 146 organic liquids. The correct evaluation of surface tension using slab simulations of liquids requires one to properly take into account the long-range interactions (Trukhymchuk and Alejandre J. Chem. Phys.1999, 111, 8510). In addition, the liquid density from slab simulations has to be the same as that obtained in liquid simulations at constant temperature and pressure. The new results of surface tensions from this work improve those reported by Caleman et al. The OPLS/AA force field gives good surface tensions compared with experimental data for most of the systems studied in this work, although it was developed to simulate liquids. PMID:26587622

  9. Surface Tension of Organic Liquids Using the OPLS/AA Force Field.

    PubMed

    Zubillaga, Rafael A; Labastida, Ariana; Cruz, Bibiana; Martínez, Juan Carlos; Sánchez, Enrique; Alejandre, José

    2013-03-12

    Molecular dynamics simulations are performed to obtain the surface tension of 61 organic liquids using the OPLS/AA (all-atom optimized potential for liquid simulations). The force field parameters are the same as those recently used (Caleman et al. J. Chem. Theory Comput.2012, 8, 61) to determine several thermodynamic properties of 146 organic liquids. The correct evaluation of surface tension using slab simulations of liquids requires one to properly take into account the long-range interactions (Trukhymchuk and Alejandre J. Chem. Phys.1999, 111, 8510). In addition, the liquid density from slab simulations has to be the same as that obtained in liquid simulations at constant temperature and pressure. The new results of surface tensions from this work improve those reported by Caleman et al. The OPLS/AA force field gives good surface tensions compared with experimental data for most of the systems studied in this work, although it was developed to simulate liquids.

  10. Method and apparatus for the removal or bioconversion of constituents of organic liquids

    DOEpatents

    Scott, T.; Scott, C.D.

    1994-10-25

    A method and apparatus are disclosed for the removal or conversion of constituents from bulk organic liquids. A countercurrent biphasic bioreactor system is utilized to disperse and recoalesce a biocatalyst contained in the aqueous liquid phase into the organic liquid phase containing the constituent. Two transient, high-intensity electrical fields rupture the aqueous drops into a plurality of microdroplets and induce continuous coalescence and redispersion as the microdroplets travel through the organic phase, thus increasing surface area. As the aqueous microdroplets progress through the organic phase, the biocatalyst then reacts with the constituent to produce a product which is then removed from the bioreactor in the aqueous phase or retained in the organic phase. The organic liquid, now free of the original constituents, is ready for immediate use or further processing. 1 fig.

  11. Method and apparatus for the removal of bioconversion of constituents of organic liquids

    DOEpatents

    Scott, Timothy; Scott, Charles D.

    1994-01-01

    A method and apparatus for the removal or conversion of constituents from bulk organic liquids. A countercurrent biphasic bioreactor system is utilized to disperse and recoalesce a biocatalyst contained in the aqueous liquid phase into the organic liquid phase containing the constituent. Two transient, high-intensity electrical fields rupture the aqueous drops into a plurality of microdroplets and induce continuous coalescence and redispersion as the microdroplets travel through the organic phase, thus increasing surface area. As the aqueous microdroplets progress through the organic phase, the biocatalyst then reacts with the constituent to produce a product which is then removed from the bioreactor in the aqueous phase or retained in the organic phase. The organic liquid, now free of the original constituents, is ready for immediate use or further processing.

  12. Use of water-equivalent plastic scintillator for intravascular brachytherapy dosimetry.

    PubMed

    Geso, M; Robinson, N; Schumer, W; Williams, K

    2004-03-01

    Beta irradiation has recently been investigated as a possible technique for the prevention of restenosis in intravascular brachytherapy after balloon dilatation or stent implantation. Present methods of beta radiation dosimetry are primarily conducted using radiochromic film. These film dosimeters exhibit limited sensitivity and their characteristics differ from those of tissue, therefore the dose measurement readings require correction factors to be applied. In this work a novel, mini-size (2 mm diameter by 5 mm long) dosimeter element fabricated from Organic Plastic Scintillator (OPS) material was employed. Scintillation photon detection is accomplished using a precision photodiode and innovative signal amplification and processing techniques, rather than traditional photomultiplier tube methods. A significant improvement in signal to noise ratio, dynamic range and stability is achieved using this set-up. In addition, use of the non-saturating organic plastic scintillator material as the detector enables the dosimeter to measure beta radiation at very close distances to the source. In this work the plastic scintillators have been used to measure beta radiation dose at distances of less than 1 mm from an Sr-90 cardiovascular brachytherapy source having an activity of about 2.1 GBq beta radiation levels for both depth-distance and longitudinal profile of the source pellet chain, both in air and in liquid water, are measured using this system. The data obtained is compared with results from Monte Carlo simulation technique (MCNP 4B). Plastic scintillator dosimeter elements, when used in conjunction with photodiode detectors may prove to be useful dosimeters for cardiovascular brachytherapy beta sources, or other applications where precise near-source field dosimetry is required. The system described is particularly useful where measurement of actual dose rate in real time, a high level of stability and repeatability, portability, and immediate access to results are

  13. A reversible zwitterionic SO 2 -binding organic liquid

    SciTech Connect

    Heldebrant, David J.; Koech, Phillip K.; Yonker, Clement R.

    2010-01-01

    Propanol functionalized tetramethylguanidine (TMG-Pr-OH) is a liquid that reacts with CO2 to form a viscous Zwitterionic liquid that contains 20.8% by weight CO2. CO2 is chemically bound to the alcohol as an alkylcarbonate, which is then stabilized by hydrogen bonding to the guanidine component. The Zwitterionic liquid can be reverted to its non-ionic form by thermally stripping the CO2 at temperatures near 100 °C.

  14. 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

  15. Controlling the Spatial Organization of Liquid Crystalline Nanoparticles by Composition of the Organic Grafting Layer.

    PubMed

    Wójcik, Michał M; Olesińska, Magdalena; Sawczyk, Michał; Mieczkowski, Józef; Górecka, Ewa

    2015-07-01

    Understanding how the spatial ordering of liquid crystalline nanoparticles can be controlled by different factors is of great importance in the further development of their photonic applications. In this paper, we report a new key parameter to control the mesogenic behavior of gold nanoparticles modified by rodlike thiols. An efficient method to control the spatial arrangement of hybrid nanoparticles in a condensed state is developed by changing the composition of the mesogenic grafting layer on the surface of the nanoparticles. The composition can be tuned by different conditions of the ligand exchange reaction. The thermal and optical behavior of the mesogenic and promesogenic ligands were investigated by using differential scanning calorimetry (DSC) and hot-stage polarized optical microscopy. The chemical structure of the synthesized hybrid nanoparticles was characterized by (1) H NMR spectroscopy, thermogravimetric analysis (TGA), XPS, and elemental analysis, whereas the superstructures were examined by small-angle X-ray diffraction (SAXSRD) analysis. Structural studies showed that the organic sublayer made of mesogenic ligands is denser with an increasing the average ligand number, thereby separating the nanoparticles in the liquid crystalline phases, which changes the parameters of these phases.

  16. Influence of surfactant tail branching and organization on the orientation of liquid crystals at aqueous-liquid crystal interfaces.

    PubMed

    Lockwood, Nathan A; de Pablo, Juan J; Abbott, Nicholas L

    2005-07-19

    We have examined the influence of two aspects of surfactant structure--tail branching and tail organization--on the orientational ordering (so-called anchoring) of water-immiscible, thermotropic liquid crystals in contact with aqueous surfactant solutions. First, we evaluated the influence of branches in surfactant tails on the anchoring of nematic liquid crystals at water-liquid crystal interfaces. We compared interfaces that were laden with one of three linear surfactants (sodium dodecyl sulfate, sodium dodecanesulfonate, and isomerically pure linear sodium dodecylbenzenesulfonate) to interfaces laden with branched sodium dodecylbenzenesulfonate. We carried out these experiments at 60 degrees C, above the Krafft temperatures of all the surfactants studied, and used the liquid crystal TL205 (a mixture of cyclohexane-fluorinated biphenyls and fluorinated terphenyls), which forms a nematic phase at 60 degrees C. Linear surfactants caused TL205 to assume a perpendicular orientation (homeotropic anchoring) above a threshold concentration of surfactant and parallel orientation (planar anchoring) at lower concentrations. In contrast, branched sodium dodecylbenzenesulfonate caused planar anchoring of TL205 at all concentrations up to the critical micelle concentration of the surfactant. Second, we used sodium dodecanesulfonate and a commercial linear sodium dodecylbenzenesulfonate to probe the influence of surfactant tail organization on the orientations of liquid crystals at water-liquid crystal interfaces. Commercial linear sodium dodecylbenzenesulfonate, which comprises a mixture of ortho and para isomers, has been previously characterized to form less ordered monolayers than sodium dodecanesulfonate at oil-water interfaces at room temperature. We found sodium dodecanesulfonate to cause homeotropic anchoring of both TL205 and 4'-pentyl-4-cyanobiphenyl (5CB, nematic at room temperature), whereas commercial linear sodium dodecylbenzenesulfonate caused predominantly

  17. HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY OF SELECTED ORGANIC PEROXIDES WITH OXIDATIVE AMPEROMETRIC DETECTION

    EPA Science Inventory

    Reversed-phase high-performance liquid chromatography with oxidative amperometric detection was optimized for the determination of several organic peroxides in drinking water under ideal conditions.The determinations were performed under isocratic conditions using acetonitrile an...

  18. Strongly Dichroic Organic Films via Controlled Assembly of Modular Aromatic Charge-Transfer Liquid Crystals.

    PubMed

    Bé, Ariana Gray; Tran, Cheryl; Sechrist, Riley; Reczek, Joseph J

    2015-10-01

    The formation of highly anisotropic organic thin films based on the designed self-assembly of mixed-stack liquid crystals is reported. A series of alkoxyanthracene donors is combined in a modular fashion with a naphthalenediimide acceptor to generate new charge-transfer columnar liquid crystals. Materials characterization and molecular modeling provides insight into structure-function relationships in these organic materials that lead to the striking bulk dichroic properties of certain molecular assemblies.

  19. Strongly Dichroic Organic Films via Controlled Assembly of Modular Aromatic Charge-Transfer Liquid Crystals.

    PubMed

    Bé, Ariana Gray; Tran, Cheryl; Sechrist, Riley; Reczek, Joseph J

    2015-10-01

    The formation of highly anisotropic organic thin films based on the designed self-assembly of mixed-stack liquid crystals is reported. A series of alkoxyanthracene donors is combined in a modular fashion with a naphthalenediimide acceptor to generate new charge-transfer columnar liquid crystals. Materials characterization and molecular modeling provides insight into structure-function relationships in these organic materials that lead to the striking bulk dichroic properties of certain molecular assemblies. PMID:26375256

  20. A compendium on the NIST radionuclide assays of the massic activity of {sup 63}Ni and {sup 55}Fe solutions used for an international intercomparison of liquid scintillation spectrometry techniques

    SciTech Connect

    Colle, R.; Zimmerman, B.E.

    1997-09-01

    The National Institute of Standards and Technology recently participated in an international measurement intercomparison for {sup 63}Ni and {sup 55}Fe, which was conducted among principal national radionuclidic metrology laboratories. The intercomparison was sponsored by EUROMET, and was primarily intended to evaluate the capabilities of liquid scintillation (LS) spectrometry techniques for standardizing nuclides that decay by low-energy {beta}-emission (like {sup 63}Ni) and by low-Z (atomic number) electron capture (like {sup 55}Fe). The intercomparison findings exhibit a very good agreement for {sup 63}Ni among the various participating laboratories, including that for NIST, which suggests that the presently invoked LS methodologies are very capable of providing internationally-compatible standardizations for low-energy {beta}-emitters. The results for {sup 55}Fe are in considerably poorer agreement, and demonstrated the existence of several unresolved problems. It has thus become apparent that there is a need for the various international laboratories to conduct rigorous, systematic evaluations of their LS capabilities in assaying radionuclides that decay by low-Z electron capture.

  1. Testing Scintillators for Homeland Security

    NASA Astrophysics Data System (ADS)

    Bourbeau, James; Brandt, Andrew; Kenarangui, Rasool; Weiss, Alex; Chen, Wei

    2011-10-01

    Scintillating nanoparticles have a bright future in radiation detection, especially in the area of detecting nuclear devices. As part of a UTA nanoparticle scintillator development team funded by the Department of Homeland Security, I have been developing a scintillator test stand using various radioactive sources and a Hamamatsu S3590 photodiode. I will present initial test results.

  2. Using FT-IR Spectroscopy to Measure Charge Organization in Ionic Liquids

    PubMed Central

    Burba, Christopher M.; Janzen, Jonathan; Butson, Eric D.; Coltrain, Gage L.

    2013-01-01

    A major goal in the field of ionic liquids is correlating transport property trends with the underlying liquid structure of the compounds, such as the degree of charge organization among the constituent ions. Traditional techniques for experimentally assessing charge organization are specialized and not readily available for routine measurements. This represents a significant roadblock in elucidating these correlations. We use a combination of transmission and polarized-ATR infrared spectroscopy to measure the degree of charge organization for ionic liquids. The technique is illustrated with a family of 1-alkyl-3-methylimidazolium trifluoromethansulfonate ionic liquids at 30°C. As expected, the amount of charge organization decreases as the alkyl side chain is lengthened, highlighting the important role of short-range repulsive interactions in defining quasilattice structure. Inherent limitations of the method are identified and discussed. The quantitative measurements of charge organization are then correlated with trends in the transport properties of the compounds to highlight the relationship between charge and momentum transport and the underlying liquid structure. Most research laboratories possess infrared spectrometers capable of conducting these measurements, thus, the proposed method may represent a cost-effective solution for routinely measuring charge organization in ionic liquids. PMID:23781877

  3. Chemical reactions of metal powders with organic and inorganic liquids during ball milling

    NASA Technical Reports Server (NTRS)

    Arias, A.

    1975-01-01

    Chromium and/or nickel powders were milled in metal chlorides and in organic liquids representative of various functional groups. The powders always reacted with the liquid and became contaminated with elements from them. The milled powders had specific surface areas ranging from 0.14 to 37 sq m/g, and the total contamination with elements from the milling liquid ranged from 0.01 to 56 weight percent. Compounds resulting from substitution, addition, or elimination reactions formed in or from the milling liquid.

  4. Characterizing and validating the PROSPECT segmented scintillator detector design

    NASA Astrophysics Data System (ADS)

    Norcini, Danielle; Prospect Collaboration

    2016-03-01

    The PROSPECT experiment will use two segmented liquid scintillator detectors positioned 7-20m from the High Flux Isotope Reactor (HFIR) core to perform a search for eV-scale sterile neutrinos and measure the antineutrino spectrum of uranium-235. A multi-year R&D program focused on background studies at the HFIR reactor, lithium-loaded liquid scintillator development, and characterization of multiple prototype detectors has culminated in the design of a segmented, 3-ton liquid scintillator detector for PROSPECT Phase I. This detector design is being validated with a 50 liter, 2-segment prototype detector, PROSPECT-50. We will report results of on-going performance and calibration studies and discuss implications for the PROSPECT physics program.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Development of dispersive liquid-liquid microextraction based on solidification of floating organic drop for the determination of trace nickel.

    PubMed

    Wang, Yukun; Zhang, Jingwen; Zhao, Bin; Du, Xin; Ma, Jingjun; Li, Jingci

    2011-12-01

    A liquid-phase microextraction technique was developed using dispersive liquid-liquid microextraction based on solidification of floating organic drop combined with flame atomic absorption spectrometry, for the extraction and determination of trace amounts of nickel in water samples. Microextraction efficiency factors, such as the type and volume of extraction and dispersive solvents, pH, extraction time, the chelating agent amount, and ionic strength, were investigated and optimized. Under optimum conditions, the calibration graph was linear in the range of 4.23-250 μg L(-1) with a detection limit of 1.27 μg L(-1). The relative standard deviation for ten replicate measurements of 10 and 100 μg L(-1) of nickel were 3.21% and 2.55%, respectively. The proposed method was assessed through the analysis of certified reference water or recovery experiments. PMID:21598026

  10. Vacuum Surface Science Meets Heterogeneous Catalysis: Dehydrogenation of a Liquid Organic Hydrogen Carrier in the Liquid State.

    PubMed

    Matsuda, Takashi; Taccardi, Nicola; Schwegler, Johannes; Wasserscheid, Peter; Steinrück, Hans-Peter; Maier, Florian

    2015-06-22

    Ultrahigh vacuum (UHV) surface science techniques are used to study the heterogeneous catalytic dehydrogenation of a liquid organic hydrogen carrier in its liquid state close to the conditions of real catalysis. For this purpose, perhydrocarbazole (PH), otherwise volatile under UHV, is covalently linked as functional group to an imidazolium cation, forming a non-volatile ionic liquid (IL). The catalysed dehydrogenation of the PH unit as a function of temperature is investigated for a Pt foil covered by a macroscopically thick PH-IL film and for Pd particles suspended in the PH-IL film, and for PH-IL on Au as inert support. X-ray photoelectron spectroscopy and thermal desorption spectroscopy allows us to follow in situ the catalysed transition of perhydrocarbazole to carbazole at technical reaction temperatures. The data demonstrate the crucial role of the Pt and Pd catalysts in order to shift the dehydrogenation temperature below the critical temperature of thermal decomposition.

  11. Method for monitoring the crystallization of an organic material from a liquid

    DOEpatents

    Asay, Blaine W.; Henson, Bryan F.; Sander, Robert K.; Robinson, Jeanne M.; Son, Steven F.; Dickson, Peter M.

    2004-10-05

    Method for monitoring the crystallization of at least one organic material from a liquid. According to the method, a liquid having at least one organic material capable of existing in at least one non-centrosymmetric phase is prepared. The liquid is interrogated with a laser beam at a chosen wavelength. As at least a portion of the at least one organic material crystallizes from the liquid, the intensity of any light scattered by the crystallized material at a wavelength equal to one-half the chosen wavelength of the interrogating laser beam is monitored. If the intensity of this scattered light, increases, then the crystals that form include at least one non-cetrosymmetric phase.

  12. Reverse osmosis molecular differentiation of organic liquids using carbon molecular sieve membranes

    NASA Astrophysics Data System (ADS)

    Koh, Dong-Yeun; McCool, Benjamin A.; Deckman, Harry W.; Lively, Ryan P.

    2016-08-01

    Liquid-phase separations of similarly sized organic molecules using membranes is a major challenge for energy-intensive industrial separation processes. We created free-standing carbon molecular sieve membranes that translate the advantages of reverse osmosis for aqueous separations to the separation of organic liquids. Polymer precursors were cross-linked with a one-pot technique that protected the porous morphology of the membranes from thermally induced structural rearrangement during carbonization. Permeation studies using benzene derivatives whose kinetic diameters differ by less than an angstrom show kinetically selective organic liquid reverse osmosis. Ratios of single-component fluxes for para- and ortho-xylene exceeding 25 were observed and para- and ortho- liquid mixtures were efficiently separated, with an equimolar feed enriched to 81 mole % para-xylene, without phase change and at ambient temperature.

  13. Reverse osmosis molecular differentiation of organic liquids using carbon molecular sieve membranes.

    PubMed

    Koh, Dong-Yeun; McCool, Benjamin A; Deckman, Harry W; Lively, Ryan P

    2016-08-19

    Liquid-phase separations of similarly sized organic molecules using membranes is a major challenge for energy-intensive industrial separation processes. We created free-standing carbon molecular sieve membranes that translate the advantages of reverse osmosis for aqueous separations to the separation of organic liquids. Polymer precursors were cross-linked with a one-pot technique that protected the porous morphology of the membranes from thermally induced structural rearrangement during carbonization. Permeation studies using benzene derivatives whose kinetic diameters differ by less than an angstrom show kinetically selective organic liquid reverse osmosis. Ratios of single-component fluxes for para- and ortho-xylene exceeding 25 were observed and para- and ortho- liquid mixtures were efficiently separated, with an equimolar feed enriched to 81 mole % para-xylene, without phase change and at ambient temperature. PMID:27540170

  14. Soft magnets from the self-organization of magnetic nanoparticles in twisted liquid crystals.

    PubMed

    Matt, Benjamin; Pondman, Kirsten M; Asshoff, Sarah J; Ten Haken, Bennie; Fleury, Benoit; Katsonis, Nathalie

    2014-11-10

    Organizing magnetic nanoparticles into long-range and dynamic assemblies would not only provide new insights into physical phenomena but also open opportunities for a wide spectrum of applications. In particular, a major challenge consists of the development of nanoparticle-based materials for which the remnant magnetization and coercive field can be controlled at room temperature. Our approach consists of promoting the self-organization of magnetic nanoparticles in liquid crystals (LCs). Using liquid crystals as organizing templates allows us to envision the design of tunable self-assemblies of magnetic nanoparticles, because liquid crystals are known to reorganize under a variety of external stimuli. Herein, we show that twisted liquid crystals can be used as efficient anisotropic templates for superparamagnetic nanoparticles and demonstrate the formation of hybrid soft magnets at room temperature.

  15. 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.

  16. 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.

  17. Measurement and Estimation of Organic-Liquid/Water Interfacial Areas for Several Natural Porous Media

    SciTech Connect

    Brusseau, M.L.; Narter, M.; Schnaar, G.; Marble, J.

    2009-06-01

    The objective of this study was to quantitatively characterize the impact of porous-medium texture on interfacial area between immiscible organic liquid and water residing within natural porous media. Synchrotron X-ray microtomography was used to obtain high-resolution, three-dimensional images of solid and liquid phases in packed columns. The image data were processed to generate quantitative measurements of organic-liquid/water interfacial area and of organic-liquid blob sizes. Ten porous media, comprising a range of median grain sizes, grain-size distributions, and geochemical properties, were used to evaluate the impact of porous-medium texture on interfacial area. The results show that fluid-normalized specific interfacial area (A{sub f}) and maximum specific interfacial area (A{sub m}) correlate very well to inverse median grain diameter. These functionalities were shown to result from a linear relationship between effective organic-liquid blob diameter and median grain diameter. These results provide the basis for a simple method for estimating specific organic-liquid/water interfacial area as a function of fluid saturation for a given porous medium. The availability of a method for which the only parameter needed is the simple-to-measure median grain diameter should be of great utility for a variety of applications.

  18. Comparative testing of various flow-cell detectors fabricated using CaF{sub 2} solid scintillator

    SciTech Connect

    Kawano, T.; Ohashi, H.; Hamada, Y.; Jamsranjav, E.

    2015-03-15

    A monitoring system based on a flow-cell detector was developed for measuring the tritium concentration in water. The flow-cell detector was fabricated using a granular CaF{sub 2} solid scintillator. This system does not use a liquid scintillation counting system and does not generate radioactive organic liquid waste. Moreover, continuous real-time measurements are possible, in contrast to a liquid scintillation counting system, which requires batch measurements. For further development of the system, four flow-cell detectors were fabricated. They included a single 3-mm-diameter cell, three 3-mm-diameter cells in series, a single 5-mm-diameter cell, and three 5-mm-diameter cells in series. Continuously flowing water containing tritium at various concentrations was passed through the flow cells, and tritium count were measured for 600 and 10000 s. Investigating the relation between the count rate and concentration, the three 5-mm-diameter cells were most sensitive, with a linear relation maintained down to approximately 2 Bq/ml and 10 Bq/ml for 10000- and 600-s measurements, respectively. (authors)

  19. THERMODYNAMIC MODELING OF LIQUID AEROSOLS CONTAINING DISSOLVED ORGANICS AND ELECTROLYTES

    EPA Science Inventory

    Many tropospheric aerosols contain large fractions of soluble organic material, believed to derive from the oxidation of precursors such alpha-pinene. The chemical composition of aerosol organic matter is complex and not yet fully understood.

    The key properties of solu...

  20. 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.

  1. 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.

  2. Scintillating Cocktail Mixtures and the Role of Water on the Optophysical Properties.

    SciTech Connect

    Cordaro, Joseph Gabriel; Feng, Patrick L.; Mengesha, Wondwosen; Murtagh, Dustin; Anstey, Mitchell

    2015-10-01

    Two types of water - containing liquid scinti llation mixtures were prepared in the present work. In the first, m ixtures of 2 - phenylethanol, water, diphenyl phosphate, sodium phenyl phosphate dibasic dihydrate, and the dye 2,5 - diphenyloxazole (PPO) have been investigated as liquid scintillators. In th e second system, nonionic and mixed surfactant systems were investigated in conjunction with water and small amounts of toluene. In both cases, increasing amounts of water led to reductions in the scintillation light yield. Understanding what factors contr ibute to this phenomenon is the focus of this report. Changes in the solution microphase structure, diminishing aromatic content of the cocktail mixtures, and inefficient energy transfer to the dye a ppear to be responsible for the decreased light yield as more water is added . In the 2 - phenylethanol system, the observed experimental results are consistent with the formation of a bicontinuous microemulsion at higher water concentrations, which incorporates PPO and shields it from the quenching effects of the increasing polar matrix. Evidence for this proposed phase chan ge c ome s from light scattering data, photo - and x - ray luminescence measurements, and optical transparency measurements . In the surfactant - based system, the quenching effect of water was found to be less than both commercially - available dioxane - naphthalene mixtures used for scintillation counting as well as the 2 - phenylethanol mixtures described above. The effect of different surfactant mixtures and concentrations were studied, revealing a benefic ial effect upon the scintillation light yield for mixed surfactant mixtures. These results are interpreted in the context of r eactive radical species formation following water ionization , which leads to light - yield quenching in aqueous systems . The presenc e of surfactant(s) in these mixtures enables the formation of organic - rich regions that are spatially separated from the

  3. Estimation of Interfacial Tension between Organic Liquid Mixtures and Water

    SciTech Connect

    Yoon, Hongkyu; Oostrom, Martinus; Werth, Charles J.

    2009-10-15

    Knowledge of IFT values for chemical mixtures helps guide the design and analysis of various processes, including NAPL remediation with surfactants or alcohol flushing, enhanced oil recovery, and chemical separation technologies, yet available literature values are sparse. A comprehensive comparison of thermodynamic and empirical models for estimating interfacial tension (IFT) of organic chemical mixtures with water is conducted, mainly focusing on chlorinated organic compounds for 14 ternary, three quaternary, and one quinary systems. Emphasis is placed on novel results for systems with three and four organic chemical compounds, and for systems with composite organic compounds like lard oil and mineral oil. Seven models are evaluated: the ideal and nonideal monolayer models (MLID and MLNID), the ideal and nonideal mutual solubility models (MSID and MSNID), an empirical model for ternary systems (EM), a linear mixing model based on mole fractions (LMMM), and a newly developed linear mixing model based on volume fractions of organic mixtures (LMMV) for higher order systems. The two ideal models (MLID and MSID) fit ternary systems of chlorinated organic compounds without surface active compounds relatively well. However, both ideal models did not perform well for the mixtures containing a surface active compound. However, for these systems, both the MLNID and MSNID models matched the IFT data well. It is shown that the MLNID model with a surface coverage value (0.00341 mmol/m2) obtained in this study can practically be used for chlorinated organic compounds. The LMMM results in poorer estimates of the IFT as the difference in IFT values of individual organic compounds in a mixture increases. The EM, with two fitting parameters, provided accurate results for all 14 ternary systems including composite organic compounds. The new LMMV method for quaternary and higher component systems was successfully tested. This study shows that the LMMV may be able to be used for

  4. Shear-Triggered Crystallization and Light Emission of a Thermally Stable Organic Supercooled Liquid.

    PubMed

    Chung, Kyeongwoon; Kwon, Min Sang; Leung, Brendan M; Wong-Foy, Antek G; Kim, Min Su; Kim, Jeongyong; Takayama, Shuichi; Gierschner, Johannes; Matzger, Adam J; Kim, Jinsang

    2015-05-27

    Thermodynamics drive crystalline organic molecules to be crystallized at temperatures below their melting point. Even though molecules can form supercooled liquids by rapid cooling, crystalline organic materials readily undergo a phase transformation to an energetically favorable crystalline phase upon subsequent heat treatment. Opposite to this general observation, here, we report molecular design of thermally stable supercooled liquid of diketopyrrolopyrrole (DPP) derivatives and their intriguing shear-triggered crystallization with dramatic optical property changes. Molten DPP8, one of the DPP derivatives, remains as stable supercooled liquid without crystallization through subsequent thermal cycles. More interestingly, under shear conditions, this supercooled liquid DPP8 transforms to its crystal phase accompanied by a 25-fold increase in photoluminescence (PL) quantum efficiency and a color change. By systematic investigation on supercooled liquid formation of crystalline DPP derivatives and their correlation with chemical structures, we reveal that the origin of this thermally stable supercooled liquid is a subtle force balance between aromatic interactions among the core units and van der Waals interactions among the aliphatic side chains acting in opposite directions. Moreover, by applying shear force to a supercooled liquid DPP8 film at different temperatures, we demonstrated direct writing of fluorescent patterns and propagating fluorescence amplification, respectively. Shear-triggered crystallization of DPP8 is further achieved even by living cell attachment and spreading, demonstrating the high sensitivity of the shear-triggered crystallization which is about 6 orders of magnitude more sensitive than typical mechanochromism observed in organic materials. PMID:27162955

  5. Shear-Triggered Crystallization and Light Emission of a Thermally Stable Organic Supercooled Liquid

    PubMed Central

    2015-01-01

    Thermodynamics drive crystalline organic molecules to be crystallized at temperatures below their melting point. Even though molecules can form supercooled liquids by rapid cooling, crystalline organic materials readily undergo a phase transformation to an energetically favorable crystalline phase upon subsequent heat treatment. Opposite to this general observation, here, we report molecular design of thermally stable supercooled liquid of diketopyrrolopyrrole (DPP) derivatives and their intriguing shear-triggered crystallization with dramatic optical property changes. Molten DPP8, one of the DPP derivatives, remains as stable supercooled liquid without crystallization through subsequent thermal cycles. More interestingly, under shear conditions, this supercooled liquid DPP8 transforms to its crystal phase accompanied by a 25-fold increase in photoluminescence (PL) quantum efficiency and a color change. By systematic investigation on supercooled liquid formation of crystalline DPP derivatives and their correlation with chemical structures, we reveal that the origin of this thermally stable supercooled liquid is a subtle force balance between aromatic interactions among the core units and van der Waals interactions among the aliphatic side chains acting in opposite directions. Moreover, by applying shear force to a supercooled liquid DPP8 film at different temperatures, we demonstrated direct writing of fluorescent patterns and propagating fluorescence amplification, respectively. Shear-triggered crystallization of DPP8 is further achieved even by living cell attachment and spreading, demonstrating the high sensitivity of the shear-triggered crystallization which is about 6 orders of magnitude more sensitive than typical mechanochromism observed in organic materials. PMID:27162955

  6. Compressed and saturated liquid densities for 18 halogenated organic compounds

    SciTech Connect

    Defibaugh, D.R.; Moldover, M.R.

    1997-01-01

    The pressure-density-temperature P({rho},T) behavior of 18 liquids that are potential working fluids in thermal machinery has been measured using a vibrating tube densimeter. For each liquid, the data were taken on isotherms spaced at intervals of 5 K to 10 K spanning the temperature range 245 K to 370 K. The pressures ranged from just above the vapor pressure (or the critical pressure) to 6500 kPa. The results of measurements at more than 12,000 thermodynamic points are summarized by correlating functions. Comparison with data from other laboratories indicates that the relative expanded uncertainty in the measured densities is less than 0.05%, except in the critical region. The repeatability of the vapor pressure to obtain the density of the liquid at the vapor pressure. The fluids studied (and their designations by the refrigeration industry) were trichlorofluoromethane (R11), chlorodifluoromethane (R22), 1,1-dichloro-2,2,2-trifluoroethane (R123), 1,2-dichloro-1,2,2-trifluoroethane (R123a), 1-chloro-1,2,2,2-tetrafluoroethane (R124), 1,1,2,2-tetrafluoroethane (R134), 1,1,1,2-tetrafluoroethane (R134a), 1,1-dichloro-1-fluoroethane (R141b), 1,1,1-trifluoroethane (R143), 1,1,2-trifluoroethane (R143a), pentafluorodimethyl ether (E125), 1,1-difluoroethane (R152a), octafluoropropane (R218), 1,1,1,2,3,3,3-heptafluoropropane (R227ea), 2-(difluoromethoxy)-1,1,1-trifluoroethane (E245), 1,1,1,2,2-pentafluoropropane (R245cb), 1,1,1,3,3-pentafluoropropane (R245fa), and propane (R290).

  7. Mixed organic compound-ionic liquid electrolytes for lithium battery electrolyte systems

    NASA Astrophysics Data System (ADS)

    Montanino, M.; Moreno, M.; Carewska, M.; Maresca, G.; Simonetti, E.; Lo Presti, R.; Alessandrini, F.; Appetecchi, G. B.

    2014-12-01

    The thermal, transport, rheological and flammability properties of electrolyte mixtures, proposed for safer lithium-ion battery systems, were investigated as a function of the mole composition. The blends were composed of a lithium salt (LiTFSI), organic solvents (namely EC, DEC) and an ionic liquid (PYR13TFSI). The main goal is to combine the fast ion transport properties of the organic compounds with the safe issues of the non-flammable and non-volatile ionic liquids. Preliminary tests in batteries have evidenced cycling performance approaching that observed in commercial organic electrolytes.

  8. Method of loading organic materials with group III plus lanthanide and actinide elements

    DOEpatents

    Bell, Zane W.; Huei-Ho, Chuen; Brown, Gilbert M.; Hurlbut, Charles

    2003-04-08

    Disclosed is a composition of matter comprising a tributyl phosphate complex of a group 3, lanthanide, actinide, or group 13 salt in an organic carrier and a method of making the complex. These materials are suitable for use in solid or liquid organic scintillators, as in x-ray absorption standards, x-ray fluorescence standards, and neutron detector calibration standards.

  9. Underwater Spontaneous Pumpless Transportation of Nonpolar Organic Liquids on Extreme Wettability Patterns.

    PubMed

    Huang, Shuai; Song, Jinlong; Lu, Yao; Chen, Faze; Zheng, Huanxi; Yang, Xiaolong; Liu, Xin; Sun, Jing; Carmalt, Claire J; Parkin, Ivan P; Xu, Wenji

    2016-02-10

    Spontaneous pumpless transportation (SPT) of liquids has generated tremendous demands in microfluidic systems and advanced devices. However, the transportation of nonpolar organic liquids on open platforms underwater remains a challenge because most existing SPT systems are only designed for use in air. Here, we report a surface-tension-driven SPT system to transport various nonpolar organic liquids using underwater extreme wettability patterns. The patterns were fabricated with a wedge-shaped superoleophilic track on a superoleophobic background by combining CuCl2 etching, stearic acid modification, and mask-based nitrogen cold plasma treatment. Three types of underwater SPT processes-horizontal transport, tilted transport, and directional transport-were studied experimentally and theoretically. For horizontal SPT and tilted SPT, the capillary force was the main driving force, which depended on the wedge angle of the superoleophilic track. The excellent transportation ability of horizontal SPT of underwater liquid droplets was obtained at a wedge angle of 3-5°. The maximum moving height of organic liquids on the tilted SPT transport was obtained at an angle of 8°. For directional SPT, organic liquids did not drop off in the moving process because of the constraint imposed by surface tension, resulting in the sustained directional transport with long distances and complex trajectories.

  10. Sorption of vapors of some organic liquids on soil humic acid and its relation to partitioning of organic compounds in soil organic matter

    USGS Publications Warehouse

    Chlou, G.T.; Kile, D.E.; Malcolm, R.L.

    1988-01-01

    Vapor sorption of water, ethanol, benzene, hexane, carbon tetrachloride, 1,1,1-trichloroethane, trichloroethylene, tetrachloroethylene, and 1,2-dibromoethane on (Sanhedron) soil humic acid has been determined at room temperature. Isotherms for all organic liquids are highly linear over a wide range of relative pressure (P/P??), characteristic of the partitioning (dissolution) of the organic compounds in soil humic acid. Polar liquids exhibit markedly greater sorption capacities on soil humic acid than relatively nonpolar liquids, in keeping with the polar nature of the soil humic acid as a partition medium. The limiting sorption (partition) capacities of relatively non-polar liquids are remarkably similar when expressed in terms of volumes per unit weight of soil humic acid. The soil humic acid is found to be about half as effective as soil organic matter in sorption of relatively nonpolar organic compounds. The nearly constant limiting sorption capacity for nonpolar organic liquids with soil humic acid on a volume-to-weight basis and its efficiency in sorption relative to soil organic matter provide a basis for predicting the approximate sorption (partition) coefficients of similar compounds in uptake by soil in aqueous systems.

  11. 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

  12. Analysis of a gas-liquid film plasma reactor for organic compound oxidation.

    PubMed

    Hsieh, Kevin; Wang, Huijuan; Locke, Bruce R

    2016-11-01

    A pulsed electrical discharge plasma formed in a tubular reactor with flowing argon carrier gas and a liquid water film was analyzed using methylene blue as a liquid phase hydroxyl radical scavenger and simultaneous measurements of hydrogen peroxide formation. The effects of liquid flow rate, liquid conductivity, concentration of dye, and the addition of ferrous ion on dye decoloration and degradation were determined. Higher liquid flow rates and concentrations of dye resulted in less decoloration percentages and hydrogen peroxide formation due to initial liquid conductivity effects and lower residence times in the reactor. The highest decoloration energy yield of dye found in these studies was 5.2g/kWh when using the higher liquid flow rate and adding the catalyst. The non-homogeneous nature of the plasma discharge favors the production of hydrogen peroxide in the plasma-liquid interface over the chemical oxidation of the organic in the bulk liquid phase and post-plasma reactions with the Fenton catalyst lead to complete utilization of the plasma-formed hydrogen peroxide. PMID:27267693

  13. Analysis of a gas-liquid film plasma reactor for organic compound oxidation.

    PubMed

    Hsieh, Kevin; Wang, Huijuan; Locke, Bruce R

    2016-11-01

    A pulsed electrical discharge plasma formed in a tubular reactor with flowing argon carrier gas and a liquid water film was analyzed using methylene blue as a liquid phase hydroxyl radical scavenger and simultaneous measurements of hydrogen peroxide formation. The effects of liquid flow rate, liquid conductivity, concentration of dye, and the addition of ferrous ion on dye decoloration and degradation were determined. Higher liquid flow rates and concentrations of dye resulted in less decoloration percentages and hydrogen peroxide formation due to initial liquid conductivity effects and lower residence times in the reactor. The highest decoloration energy yield of dye found in these studies was 5.2g/kWh when using the higher liquid flow rate and adding the catalyst. The non-homogeneous nature of the plasma discharge favors the production of hydrogen peroxide in the plasma-liquid interface over the chemical oxidation of the organic in the bulk liquid phase and post-plasma reactions with the Fenton catalyst lead to complete utilization of the plasma-formed hydrogen peroxide.

  14. Why can organic liquids move easily on smooth alkyl-terminated surfaces?

    PubMed

    Urata, Chihiro; Masheder, Benjamin; Cheng, Dalton F; Miranda, Daniel F; Dunderdale, Gary J; Miyamae, Takayuki; Hozumi, Atsushi

    2014-04-15

    The dynamic dewettability of a smooth alkyl-terminated sol-gel hybrid film surface against 17 probe liquids (polar and nonpolar, with high and low surface tensions) was systematically investigated using contact angle (CA) hysteresis and substrate tilt angle (TA) measurements, in terms of their physicochemical properties such as surface tension, molecular weight/volume, dielectric constant, density, and viscosity. We found that the dynamic dewettability of the hybrid film markedly depended not on the surface tensions but on the dielectric constants of the probe liquids, displaying lower resistance to liquid drop movement with decreasing dielectric constant (ε < 30). Interfacial analysis using the sum-frequency generation (SFG) technique confirmed that the conformation of surface-tethered alkyl chains was markedly altered before and after contact with the different types of probe liquids. When probe liquids with low dielectric constants were in contact with our surface, CH3 groups were preferentially exposed at the solid/liquid interface, leading to a reduction in surface energy. Because of such local changes in surface energy at the three-phase contact line of the probe liquid, the contact line can move continuously from low-surface-energy (solid/liquid) areas to surrounding high-surface-energy (solid/air) areas without pinning. Consequently, the organic probe liquids with low dielectric constants can move easily and roll off when tilted only slightly, independent of the magnitude of CAs, without relying on conventional surface roughening and perfluorination.

  15. A high liquid yield process for retorting various organic materials including oil shale

    DOEpatents

    Coburn, T.T.

    1988-07-26

    This invention is a continuous retorting process for various high molecular weight organic materials, including oil shale, that yields an enhanced output of liquid product. The organic material, mineral matter, and an acidic catalyst, that appreciably adsorbs alkenes on surface sites at prescribed temperatures, are mixed and introduced into a pyrolyzer. A circulating stream of olefin enriched pyrolysis gas is continuously swept through the organic material and catalyst, whereupon, as the result of pyrolysis, the enhanced liquid product output is provided. Mixed spent organic material, mineral matter, and cool catalyst are continuously withdrawn from the pyrolyzer. Combustion of the spent organic material and mineral matter serves to reheat the catalyst. Olefin depleted pyrolysis gas, from the pyrolyzer, is enriched in olefins and recycled into the pyrolyzer. The reheated acidic catalyst is separated from the mineral matter and again mixed with fresh organic material, to maintain the continuously cyclic process. 2 figs.

  16. High liquid yield process for retorting various organic materials including oil shale

    DOEpatents

    Coburn, Thomas T.

    1990-01-01

    This invention is a continuous retorting process for various high molecular weight organic materials, including oil shale, that yields an enhanced output of liquid product. The organic material, mineral matter, and an acidic catalyst, that appreciably adsorbs alkenes on surface sites at prescribed temperatures, are mixed and introduced into a pyrolyzer. A circulating stream of olefin enriched pyrolysis gas is continuously swept through the organic material and catalyst, whereupon, as the result of pyrolysis, the enhanced liquid product output is provided. Mixed spent organic material, mineral matter, and cool catalyst are continuously withdrawn from the pyrolyzer. Combustion of the spent organic material and mineral matter serves to reheat the catalyst. Olefin depleted pyrolysis gas, from the pyrolyzer, is enriched in olefins and recycled into the pyrolyzer. The reheated acidic catalyst is separated from the mineral matter and again mixed with fresh organic material, to maintain the continuously cyclic process.

  17. LABORATORY INVESTIGATION OF RESIDUAL LIQUID ORGANICS FROM SPILLS, LEAKS, AND THE DISPOSAL OF HAZARDOUS WASTES IN GROUNDWATER

    EPA Science Inventory

    Organic liquids that are essentially immiscible with water migrate through the subsurface under the influence of capillary, viscous, and buoyancy forces. These liquids originate from the improper disposal of hazardous wastes, and the spills and leaks of petroleum hydrocarbons a...

  18. Research on radiation detectors, boiling transients, and organic lubricants

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The accomplishments of a space projects research facility are presented. The subjects discussed are: (1) a study of radiation resistant semiconductor devices, (2) synthesis of high temperature organic lubricants, (3) departure from phase equilibrium during boiling transients, (4) effects of neutron irradiation on defect state in tungsten, and (5) determination of photon response function of NE-213 liquid scintillation detectors.

  19. Removal of non-ionic organic pollutants from water via liquid-liquid extraction.

    PubMed

    López-Montilla, Juan C; Pandey, Samir; Shah, Dinesh O; Crisalle, Oscar D

    2005-05-01

    The removal of model pollutants bromocresol green (BG) and phenol from water is demonstrated via two liquid-liquid extraction methods. Both methods exploit selective interactions established by the pollutant molecule with a surfactant, oil, or alcohol, and are variants of the more general Winsor systems where the phases are in contact along an extremely large interfacial area. In the first method the surfactant and the co-surfactant move from a predominantly oil-in-water microemulsion (Winsor I), to a middle phase microemulsion (Winsor III), and finally to a water-in-oil microemulsion (Winsor II), as the physicochemical conditions of salinity, temperature or hydrophilic-lipophilic balance of the surfactant system are varied. This method achieves better than 99% removal of the pollutant BG from water. It is argued that the removal is produced upon increasing the salinity of the system because the interaction of BG with a medium chain-length alcohol drives it to move along with the alcohol to another phase. The second method, which is scalable to industrial levels, uses a spontaneously produced water-in-oil microemulsion with large interfacial area that appears after bringing in contact water and a pre-formed Winsor II or Winsor III microemulsion system containing different surfactants and oils. The method is applied to the removal of phenol from water, and it is found that systems with polar oils such as ethyl butyrate or with cationic surfactants such as stearyl trimethylammonium chloride are more efficient in removing phenol than systems with normal alkanes or anionic surfactants. It is also shown that a microemulsion formed using a polar oil performs better than using only the polar oil as the extraction solvent. Finally, the efficiency of the second liquid-liquid extraction method can be increased from 69% in a single-stage process to 83% in a two-stage process, using the same total amount of extraction solvent.

  20. Removal of non-ionic organic pollutants from water via liquid-liquid extraction.

    PubMed

    López-Montilla, Juan C; Pandey, Samir; Shah, Dinesh O; Crisalle, Oscar D

    2005-05-01

    The removal of model pollutants bromocresol green (BG) and phenol from water is demonstrated via two liquid-liquid extraction methods. Both methods exploit selective interactions established by the pollutant molecule with a surfactant, oil, or alcohol, and are variants of the more general Winsor systems where the phases are in contact along an extremely large interfacial area. In the first method the surfactant and the co-surfactant move from a predominantly oil-in-water microemulsion (Winsor I), to a middle phase microemulsion (Winsor III), and finally to a water-in-oil microemulsion (Winsor II), as the physicochemical conditions of salinity, temperature or hydrophilic-lipophilic balance of the surfactant system are varied. This method achieves better than 99% removal of the pollutant BG from water. It is argued that the removal is produced upon increasing the salinity of the system because the interaction of BG with a medium chain-length alcohol drives it to move along with the alcohol to another phase. The second method, which is scalable to industrial levels, uses a spontaneously produced water-in-oil microemulsion with large interfacial area that appears after bringing in contact water and a pre-formed Winsor II or Winsor III microemulsion system containing different surfactants and oils. The method is applied to the removal of phenol from water, and it is found that systems with polar oils such as ethyl butyrate or with cationic surfactants such as stearyl trimethylammonium chloride are more efficient in removing phenol than systems with normal alkanes or anionic surfactants. It is also shown that a microemulsion formed using a polar oil performs better than using only the polar oil as the extraction solvent. Finally, the efficiency of the second liquid-liquid extraction method can be increased from 69% in a single-stage process to 83% in a two-stage process, using the same total amount of extraction solvent. PMID:15899289

  1. Microbial consortium role in processing liquid waste of vegetables in Keputran Market Surabaya as organic liquid fertilizer ferti-plus

    NASA Astrophysics Data System (ADS)

    Rizqi, Fauziah; Supriyanto, Agus; Lestari, Intan; Lita Indri D., L.; Elmi Irmayanti, A.; Rahmaniyah, Fadilatur

    2016-03-01

    Many activities in this market is directly proportional to increase production of vegetables waste, especially surabaya. Therefore, in this study aims to utilize liquid waste of vegetables into liquid organic fertilizer by mixing microbial consorsium. The microbial consorsium consist of Azotobacter chrococcum, Azospirillum brasilense, Rhizobium leguminosarum, Bacillus subtilis, Bacillus megaterium, Pseudomonas putida, and Pseudomonas fluorescens. Ttreatment of microbial concentrations (5%, 10%, 15%) and the length of the incubation period (7 days, 14 days, 21 days) used in this research. The parameters used are: C/N ratio, levels of CNP, and BOD value. This study uses a standard organic fertilizer value according SNI19-7030-2004, The results show the value of C/N ratio comply with the ISO standards. C levels showed an increase during the incubation period but not compare with standards. N levels that compare with standards are microbial treatment in all group concentration except control group with an incubation period of 21 days is > 7. P levels compare with the existing standards in the group of microbe concentration of 10% and 15% during the incubation period. The value of the initial BOD liquid waste of vegetable is 790.25 mg / L, this value indicates that the waste should not go into the water body. Accordingly, the results of this study can not be used as a liquid organic fertilizer, but potentially if it is used as a natural career or build natural soil. The Building natural soil is defined as the natural ingredients that can be used to improve soil properties.

  2. Liquid drop technique for generation of organic glass and metal shells

    NASA Technical Reports Server (NTRS)

    Hendricks, C. D.

    1982-01-01

    It was found that liquid drop techniques are very useful in several diverse areas. For producing very uniform metallic, organic, inorganic and, on particular, glassy shells, the liquid jet method is the most reproducible and exceptionally useful of all the techniques studied. The technique of capillary wave synchronization of the break-up of single and multiple component jets was utilized to produce uniform sized liquid drops and solid particles, and hollow liquid and solid shells. The technique was also used to encapsulate a number of liquids in impermeable spherical shells. Highly uniform glass shells were made by generating uniform drops of glass forming materials in an aqueous solution, subsequently evaporating the water, and then fusing and blowing the remaining solids in a high temperature vertical tube furnace. Experimental results are presented and the critical problems in further research in this field are discussed.

  3. Structural analysis of low melting organic salts: perspectives on ionic liquids.

    PubMed

    Dean, Pamela M; Pringle, Jennifer M; MacFarlane, Douglas R

    2010-08-28

    Ionic liquid-forming salts often display low melting points (a lack of crystallisation at ambient temperature and pressure) as a result of decreased lattice energies in the crystalline state. Intermolecular interactions between the anion and cation, and the conformational states of each component of the salt, are of significant interest as many of the distinctive properties ascribed to ionic liquids are determined to a large extent by these interactions. Crystallographic analysis provides a direct insight into the spatial relationship between the cations and anions and provides a basis for an enhanced understanding of the physico-chemical relationship of the ionic liquids. This perspective article examines the crystallographic studies of relevance to ionic liquid-forming organic salts as a basis for the rational design and synthesis of novel ionic liquids. PMID:20593067

  4. Cerium compounds as scintillators

    SciTech Connect

    Wojtowicz, A.J.; Berman, E.; Koepke, C.; Lempicki, A.

    1991-01-01

    Stoichiometric Ce-materials with negligible Ce-Ce interactions should have superior scintillator properties. We present two materials: CeF{sub 3} and Ce{sub x}La{sub 1-x}P{sub 5}O{sub 14}. While cerium trifluoride is a known scintillator, pentaphosphate is of a limited usefulness, except as a remarkable model material. We show that quenching in fluoride is responsible for loss of 50% of the light output and is the cause of the, so-called, ultra fast component (2 ns). Light output of fluoride (about 50% of BGO) could be significantly improved. Deeper understanding of Ce-systems is needed to fully exploit their potentials. 10 figs., 6 refs.

  5. Cerium compounds as scintillators

    SciTech Connect

    Wojtowicz, A.J.; Berman, E.; Koepke, C.; Lempicki, A.

    1991-12-31

    Stoichiometric Ce-materials with negligible Ce-Ce interactions should have superior scintillator properties. We present two materials: CeF{sub 3} and Ce{sub x}La{sub 1-x}P{sub 5}O{sub 14}. While cerium trifluoride is a known scintillator, pentaphosphate is of a limited usefulness, except as a remarkable model material. We show that quenching in fluoride is responsible for loss of 50% of the light output and is the cause of the, so-called, ultra fast component (2 ns). Light output of fluoride (about 50% of BGO) could be significantly improved. Deeper understanding of Ce-systems is needed to fully exploit their potentials. 10 figs., 6 refs.

  6. Membrane permeation process for dehydration of organic liquid mixtures using sulfonated ion-exchange polyalkene membranes

    DOEpatents

    Cabasso, Israel; Korngold, Emmanuel

    1988-01-01

    A membrane permeation process for dehydrating a mixture of organic liquids, such as alcohols or close boiling, heat sensitive mixtures. The process comprises causing a component of the mixture to selectively sorb into one side of sulfonated ion-exchange polyalkene (e.g., polyethylene) membranes and selectively diffuse or flow therethrough, and then desorbing the component into a gas or liquid phase on the other side of the membranes.

  7. 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.

  8. Direct Capture of Organic Acids From Fermentation Media Using Ionic Liquids

    SciTech Connect

    Klasson, K.T.

    2004-11-03

    Several ionic liquids have been investigated for the extraction of organic acids from fermentation broth. Partitioning of representative organic acids (lactic, acetic, and succinic) between aqueous solution and nine hydrophobic ionic liquids was measured. The extraction efficiencies were strongly dependent on pH of the aqueous phase. Distribution coefficient was very good (approximately 60) at low succinic acid concentrations for one of the ionic liquids (trihexyltetradecylphosphonium methanesulfonate) at neutral pH. However, this ionic liquid had to be diluted with nonanol due to its high viscosity in order to be useful. A diluent (trioctylamine) was also added to this mixture. The results suggest that an extraction system based on ionic liquids may be feasible for succinic acid recovery from fermentation broth and that two ideal extraction stages are needed to reduce the concentration from 33 g/L to 1 g/L of succinic acid. Further studies are needed to evaluate other issues related to practical applications, including ionic liquid loss in the process, toxicity effects of ionic liquids during simultaneous fermentation and extractions.

  9. Methods for calculation of engineering parameters for gas separation. [vapor pressure and solubility of gases in organic liquids

    NASA Technical Reports Server (NTRS)

    Lawson, D. D.

    1979-01-01

    A group additivity method is generated which allows estimation, from the structural formulas alone, of the energy of vaporization and the molar volume at 25 C of many nonpolar organic liquids. Using these two parameters and appropriate thermodynamic relations, the vapor pressure of the liquid phase and the solubility of various gases in nonpolar organic liquids are predicted. It is also possible to use the data to evaluate organic and some inorganic liquids for use in gas separation stages or liquids as heat exchange fluids in prospective thermochemical cycles for hydrogen production.

  10. Enhanced mineralization of organic compounds in nonaqueous-phase liquids

    SciTech Connect

    Labare, M.P.; Alexander, M.

    1995-11-01

    Biodegradation of phenanthrene, biphenyl, or di(2-ethylhexyl) phthalate initially present in a variety of nonaqueous-phase liquids (NAPLs) was slow in samples of soil and aquifer solids. The NAPLs were hexadecane, dibutyl phthalate, 2, 2, 4 ,4, 6, 8, 8-heptamethylnonane, cyclohexane, commercial oils, crude oil, creosote, and kerosene. Slurrying the soil or aquifer solids markedly enhanced the rate and extent of mineralization of the test compounds initially in many of the NAPLs. Both the low rate and extent of mineralization of the three compounds initially in dibutyl phthalate in soil slurries and of di(2- ethylhexyl) phthalate in heptamethylnonane present in slurries of aquifer solids were increased by inoculation of acclimated microbial cultures. Increasing the NAPL volume decreased phenanthrene biodegradation in soil, but the effect of larger NAPL volume could be alleviated by slurrying and inoculation. The rate or extent of mineralization in aquifer slurries of di(2-ethylhexyi) phthalate initially in some NAPLs was increased by addition of N and P, and inoculation further enhanced the degradation.

  11. Protein renaturation by the liquid organic salt ethylammonium nitrate.

    PubMed Central

    Summers, C. A.; Flowers, R. A.

    2000-01-01

    The room-temperature liquid salt, ethylammonium nitrate (EAN), has been used to enhance the recovery of denatured-reduced hen egg white lysozyme (HEWL). Our results show that EAN has the ability to prevent aggregation of the denatured protein. The use of EAN as a refolding additive is advantageous because the renaturation is a one-step process. When HEWL was denatured reduced using routine procedures and renatured using EAN as an additive, HEWL was found to regain 75% of its activity. When HEWL was denatured and reduced in neat EAN, dilution resulted in over 90% recovery of active protein. An important aspect of this process is that renaturation of HEWL occurs at concentrations of 1.6 mg/mL, whereas other renaturation processes occur at significantly lower protein concentrations. Additionally, the refolded-active protein can be separated from the molten salt by simple desalting methods. Although the use of a low-temperature molten salt in protein renaturation is unconventional, the power of this approach lies in its simplicity and utility. PMID:11106174

  12. Lunar components in Lunping scintillations

    SciTech Connect

    Koster, J.R.; Lue, H.Y.; Wu, Hsi-Shu; Huang, Yinn-Nien

    1993-08-01

    The authors report on an anlysis of a 14 year data set of ionospheric scintillation data for 136 MHz signals transmitted from a Japanese satellite. They use a lunar age superposition method to analyze this data, breaking the data into blocks by seasons of the year. They observe a number of different scintillation types in the record, as well as impacts of lunar tides on the time record. They attempt to provide an origin for the different scintillation types.

  13. 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

  14. Remotely operated organic liquid waste incinerator for the fuels and materials examination facility

    SciTech Connect

    Sales, W.L.; Barker, R.E.; Hershey, R.B.

    1980-01-01

    The search for a practical method for the disposal of small quantities of oraganic liquid waste, a waste product of metallographic sample preparation at the Fuels and Materials Examination Facility has led to the design of an incinerator/off-gas system to burn organic liquid wastes and selected organic solids. The incinerator is to be installed in a shielded inert-atmosphere cell, and will be remotely operated and maintained. The off-gas system is a wet-scrubber and filter system designed to release particulate-free off-gas to the FMEF Building Exhaust System.

  15. Nanophosphor composite scintillators comprising a polymer matrix

    DOEpatents

    Muenchausen, Ross Edward; Mckigney, Edward Allen; Gilbertson, Robert David

    2010-11-16

    An improved nanophosphor composite comprises surface modified nanophosphor particles in a solid matrix. The nanophosphor particle surface is modified with an organic ligand, or by covalently bonding a polymeric or polymeric precursor material. The surface modified nanophosphor particle is essentially charge neutral, thereby preventing agglomeration of the nanophosphor particles during formation of the composite material. The improved nanophosphor composite may be used in any conventional scintillator application, including in a radiation detector.

  16. Statistical analysis of scintillation data

    SciTech Connect

    Chua, S.; Noonan, J.P.; Basu, S.

    1981-09-01

    The Nakagami-m distribution has traditionally been used successfully to model the probability characteristics of ionospheric scintillations at UHF. This report investigates the distribution properties of scintillation data in the L-band range. Specifically, the appropriateness of the Nakagami-m and lognormal distributions is tested. Briefly the results confirm that the Nakagami-m is appropriate for UHF but not for L-band scintillations. The lognormal provides a better fit to the distribution of L-band scintillations and is an adequate model allowing for an error of + or - 0.1 or smaller in predicted probability with a sample size of 256.

  17. Graphene oxide membrane for liquid phase organic molecular separation

    NASA Astrophysics Data System (ADS)

    Liu, Renlong; Arabale, Girish; Kim, Jinseon; Sun, Ke; Lee, Yongwoon; Ryu, Changkook; Lee, Changgu

    2015-03-01

    The selective permeation of organic solvents and water through graphene oxide (GO) membranes has been demonstrated. Water was found to permeate through GO membranes faster than various alcohols. The permeation rates of propanol are about 80 times lower than that of water. Taking advantage of the differences in the permeation rates, we separated water from the alcohols and obtained alcohols with high purity. For ethanol and 1-propanol, binary solutions of the alcohol and water were filtered efficiently to produce alcohols with concentration of about 97%. However, the selectivity of the filtration of methanol is significantly lower than those of the other alcohols. To understand the mechanism we followed the structural changes in the GO membranes by X-Ray diffraction analysis. From the X-ray diffraction results we speculate that the selectivity of the permeation of water and alcohols is closely related to the molecular sizes of the solvents and their polarity. In order to demonstrate the potential applications of this process for the selective removal of water from aqueous organic mixtures, we performed the separation of water from a bio-oil containing 73% of water. The majority of the water was filtered out resulting in a higher purity bio-oil.

  18. Liquid-liquid phase separation in aerosol particles: Dependence on O:C, organic functionalities, and compositional complexity

    NASA Astrophysics Data System (ADS)

    Song, M.; Marcolli, C.; Krieger, U. K.; Zuend, A.; Peter, T.

    2012-10-01

    Atmospheric aerosol particles may undergo liquid-liquid phase separation (LLPS) when exposed to varying relative humidity. In this study we investigated the occurrence of LLPS for mixtures consisting of up to ten organic compounds, ammonium sulfate, and water in relationship with the organic oxygen-to-carbon (O:C) ratio. LLPS always occurred for O:C < 0.56, never occurred for O:C > 0.80, and depended on the specific types and compositions of organic functional groups in the regime 0.56 < O:C < 0.80. In the intermediate regime, mixtures with a high share of aromatic compounds shifted the limit of occurrence of LLPS to lower O:C ratios. The number of mixture components and the spread of the O:C range did not notably influence the conditions for LLPS to occur. Since in ambient aerosols O:C range typically between 0.2 and 1.0, LLPS is expected to be a common feature of tropospheric aerosols.

  19. Liquid-Liquid Extraction and Solid Phase Extraction for Urinary Organic Acids: A Comparative Study from a Resource Constraint Setting.

    PubMed

    Kumari, Chandrawati; Varughese, Bijo; Ramji, Siddarth; Kapoor, Seema

    2016-10-01

    Pre analytical process of extraction for accurate detection of organic acids is a crucial step in diagnosis of organic acidemias by GCMS analysis. This process is accomplished either by solid phase extraction (SPE) or by liquid-liquid extraction (LLE). Both extraction procedures are used in different metabolic laboratories all over the world. In this study we compared these two extraction procedures in respect of precision, accuracy, percent recovery of metabolites, number of metabolites isolated, time and cost in a resource constraint setup. We observed that the mean recovery from SPE was 84.1 % and by LLE it was 77.4 % (p value <0.05). Moreover, the average number of metabolites isolated by SPE and LLE was 161.8 ± 18.6 and 140.1 ± 20.4 respectively. The processing cost of LLE was economical. In a cost constraint setting using LLE may be the practical option if used for organic acid analysis. PMID:27605738

  20. 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.

  1. PREDICTION OF THE SOLUBILITY, ACTIVITY COEFFICIENT AND LIQUID/LIQUID PARTITION COEFFICIENT OF ORGANIC COMPOUNDS

    EPA Science Inventory

    Solvation models, based on fundamental chemical structure theory, were developed in the SPARC mechanistic tool box to predict a large array of physical properties of organic compounds in water and in non-aqueous solvents strictly from molecular structure. The SPARC self-interact...

  2. Capture and release of mixed acid gasses with binding organic liquids

    SciTech Connect

    Heldebrant, David J.; Yonker, Clement R.

    2010-09-21

    Reversible acid-gas binding organic liquid systems that permit separation and capture of one or more of several acid gases from a mixed gas stream, transport of the liquid, release of the acid gases from the ionic liquid and reuse of the liquid to bind more acid gas with significant energy savings compared to current aqueous systems. These systems utilize acid gas capture compounds made up of strong bases and weak acids that form salts when reacted with a selected acid gas, and which release these gases when a preselected triggering event occurs. The various new materials that make up this system can also be included in various other applications such as chemical sensors, chemical reactants, scrubbers, and separators that allow for the specific and separate removal of desired materials from a gas stream such as flue gas.

  3. Ionic Liquids Beyond Simple Solvents: Glimpses at the State of the Art in Organic Chemistry.

    PubMed

    Kuchenbuch, Andrea; Giernoth, Ralf

    2015-12-01

    Within the last 25 years ionic liquids have written a tremendous success story, which is documented in a nearly uncountable amount of original research papers, reviews, and numerous applications in research and industry. These days, ionic liquids can be considered as a mature class of compounds for many different applications. Frequently, they are used as neoteric solvents for chemical tansformations, and the number of reviews on this field of research is huge. In this focused review, though, we are trying to evaluate the state of the art of ionic liquid chemistry beyond using them simply as solvents for chemical transformations. It is not meant to be a comprehensive overview on the topic; the choice of emphasis and examples rather refects the authors' personal view on the field. We are especially highlighting fields in which we believe the most fundamental developments within the next five years will take place: biomass processing, (chiral) ionic liquids from natural sources, biotransformations, and organic synthesis.

  4. The response of scintillators to heavy ions: 1, Plastics

    SciTech Connect

    McMahan, M.A.

    1987-10-01

    The response of various scintillator detectors to ions of A = 1-84 and energies E/A = 5 to 30 MeV have been measured, and are found to be linear above an energy of 100 MeV. Results are presented for a typical organic plastic scintillator including parametrizations of the data as a function of Z, A, and energy. These results can be used by anyone using scintillators as heavy ion detectors, with one calibration point giving a normalization that allows use of the whole set of curves. The response functions are compared to previous parametrizations at lower energies and discussed in terms of the theory of delta-ray formation in the scintillator.

  5. Self-Assembled Fibers Containing Stable Organic Radical Moieties: Alignment and Magnetic Properties in Liquid Crystals.

    PubMed

    Eimura, Hiroki; Umeta, Yoshikazu; Tokoro, Hiroko; Yoshio, Masafumi; Ohkoshi, Shin-Ichi; Kato, Takashi

    2016-06-20

    Macroscopically oriented stable organic radicals have been obtained by using a liquid-crystalline (LC) gel composed of an l-isoleucine-based low molecular weight gelator containing a 2,2,6,6-tetramethylpiperidine 1-oxyl moiety. The LC gel has allowed magnetic measurements of the oriented organic radical. The gelator has formed fibrous aggregates in liquid crystals via intermolecular hydrogen bonds. The fibrous aggregates of the radical gelator are formed and oriented on cooling by applying a magnetic field to the mixture of liquid crystals and the gelator. Superconducting quantum interference device (SQUID) measurements have revealed that both oriented and nonoriented fibrous aggregates exhibited antiferromagnetic interactions, in which super-exchange interaction constant J is estimated as -0.89 cm(-1) . PMID:27219716

  6. Supramolecular [60]fullerene liquid crystals formed by self-organized two-dimensional crystals.

    PubMed

    Zhang, Xiaoyan; Hsu, Chih-Hao; Ren, Xiangkui; Gu, Yan; Song, Bo; Sun, Hao-Jan; Yang, Shuang; Chen, Erqiang; Tu, Yingfeng; Li, Xiaohong; Yang, Xiaoming; Li, Yaowen; Zhu, Xiulin

    2015-01-01

    Fullerene-based liquid crystalline materials have both the excellent optical and electrical properties of fullerene and the self-organization and external-field-responsive properties of liquid crystals (LCs). Herein, we demonstrate a new family of thermotropic [60]fullerene supramolecular LCs with hierarchical structures. The [60]fullerene dyads undergo self-organization driven by π-π interactions to form triple-layer two-dimensional (2D) fullerene crystals sandwiched between layers of alkyl chains. The lamellar packing of 2D crystals gives rise to the formation of supramolecular LCs. This design strategy should be applicable to other molecules and lead to an enlarged family of 2D crystals and supramolecular liquid crystals.

  7. Self-Assembled Fibers Containing Stable Organic Radical Moieties: Alignment and Magnetic Properties in Liquid Crystals.

    PubMed

    Eimura, Hiroki; Umeta, Yoshikazu; Tokoro, Hiroko; Yoshio, Masafumi; Ohkoshi, Shin-Ichi; Kato, Takashi

    2016-06-20

    Macroscopically oriented stable organic radicals have been obtained by using a liquid-crystalline (LC) gel composed of an l-isoleucine-based low molecular weight gelator containing a 2,2,6,6-tetramethylpiperidine 1-oxyl moiety. The LC gel has allowed magnetic measurements of the oriented organic radical. The gelator has formed fibrous aggregates in liquid crystals via intermolecular hydrogen bonds. The fibrous aggregates of the radical gelator are formed and oriented on cooling by applying a magnetic field to the mixture of liquid crystals and the gelator. Superconducting quantum interference device (SQUID) measurements have revealed that both oriented and nonoriented fibrous aggregates exhibited antiferromagnetic interactions, in which super-exchange interaction constant J is estimated as -0.89 cm(-1) .

  8. IMPACT OF ORGANIC COMPOUNDS ON THE CONCENTRATIONS OF LIQUID WATER IN AMBIENT PM2.5

    EPA Science Inventory

    A field study was undertaken during the summer of 2000 to assess the impact of the presence of organic compounds on the liquid water concentrations of PM2.5 samples. The selected site, located in Research Triangle Park, North Carolina, was in a semi-rural environment with expe...

  9. The Recovery and Identification of Flammable Liquids in Suspected Arsons: An Undergraduate Organic Experiment

    ERIC Educational Resources Information Center

    Blackledge, Robert D.

    1974-01-01

    Describes an experiment which can be used to test for the use of accelerants in the origin of a fire. Involves distillation and gas liquid chromatography to identify the accelerants, thus combining two experiments ordinarily included in the beginning organic laboratory. (SLH)

  10. Visualizing Molecular Chirality in the Organic Chemistry Laboratory Using Cholesteric Liquid Crystals

    ERIC Educational Resources Information Center

    Popova, Maia; Bretz, Stacey Lowery; Hartley, C. Scott

    2016-01-01

    Although stereochemistry is an important topic in second-year undergraduate organic chemistry, there are limited options for laboratory activities that allow direct visualization of macroscopic chiral phenomena. A novel, guided-inquiry experiment was developed that allows students to explore chirality in the context of cholesteric liquid crystals.…

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. ON-LINE DEOXYGENATION IN REDUCTIVE (AND OXIDATIVE) AMPEROMETRIC DETECTION: ENVIRONMENTAL APPLICATIONS IN THE LIQUID CHROMATOGRAPHY OF ORGANIC PEROXIDES

    EPA Science Inventory

    Cyclic voltammetry was used qualitatively to characterize and determine the feasibility of the oxidation and reduction of selected organic peroxides and hydroperoxides at a glassy carbon electrode. Organic peroxides were determined using reversed-phase high-performance liquid chr...

  16. Silica scintillating materials prepared by sol-gel methods

    SciTech Connect

    Werst, D.W.; Sauer, M.C. Jr.; Cromack, K.R.; Lin, Y.; Tartakovsky, E.A.; Trifunac, A.D.

    1993-12-31

    Silica was investigated as a rad-hard alternative to organic polymer hosts for organic scintillators. Silica sol-gels were prepared by hydrolysis of tetramethoxysilane in alcohol solutions. organic dyes were incorporated into the gels by dissolving in methanol at the sol stage of gel formation. The silica sol-gel matrix is very rad-hard. The radiation stability of silica scintillators prepared by this method is dye-limited. Transient radioluminescence was measured following excitation with 30 ps pulses of 20 MeV electrons.

  17. 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.

  18. Proton induced radiation damage in fast crystal scintillators

    NASA Astrophysics Data System (ADS)

    Yang, Fan; Zhang, Liyuan; Zhu, Ren-Yuan; Kapustinsky, Jon; Nelson, Ron; Wang, Zhehui

    2016-07-01

    This paper reports proton induced radiation damage in fast crystal scintillators. A 20 cm long LYSO crystal, a 15 cm long CeF3 crystal and four liquid scintillator based sealed quartz capillaries were irradiated by 800 MeV protons at Los Alamos up to 3.3 ×1014 p /cm2. Four 1.5 mm thick LYSO plates were irradiated by 24 GeV protons at CERN up to 6.9 ×1015 p /cm2. The results show an excellent radiation hardness of LYSO crystals against charged hadrons.

  19. Homochiral metal-organic framework used as a stationary phase for high-performance liquid chromatography.

    PubMed

    Kong, Jiao; Zhang, Mei; Duan, Ai-Hong; Zhang, Jun-Hui; Yang, Rui; Yuan, Li-Ming

    2015-02-01

    Metal-organic frameworks are promising porous materials. Chiral metal-organic frameworks have attracted considerable attention in controlling enantioselectivity. In this study, a homochiral metal-organic framework [Co(2) (D-cam)(2) (TMDPy)] (D-cam = D-camphorates, TMDPy = 4,4'-trimethylenedipyridine) with a non-interpenetrating primitive cubic net has been used as a chiral stationary phase in high-performance liquid chromatography. It has allowed the successful separation of six positional isomers and six chiral compounds. The good selectivity and baseline separation, or at least 60% valley separation, confirmed its excellent molecular recognition characteristics. The relative standard deviations for the retention time of run-to-run and column-to-column were less than 1.8 and 3.1%, respectively. These results demonstrate that [Co(2) (D-cam)(2) (TMDPy)] may represent a promising chiral stationary phase for use in high-performance liquid chromatography.

  20. Safety analysis of exothermic reaction hazards associated with the organic liquid layer in tank 241-C-103

    SciTech Connect

    Postma, A.K.; Bechtold, D.B.; Borsheim, G.L.; Grisby, J.M.; Guthrie, R.L.; Kummerer, M.; Turner, D.A.; Plys, M.G.

    1994-03-01

    Safety hazards associated with the interim storage of a potentially flammable organic liquid in waste Tank C-103 are identified and evaluated. The technical basis for closing the unreviewed safety question (USQ) associated with the floating liquid organic layer in this tank is presented.

  1. Highly effective six-wave mixing in linearly absorbing organic liquids

    NASA Astrophysics Data System (ADS)

    Agishev, I. N.; Tolstik, A. L.

    2009-04-01

    Conditions for the realization of the highly effective transformation of a light field by dynamic holograms using a scheme of frequency-nondegenerate six-wave mixing in dyed organic liquids are determined. The mechanism of the manifestation of a nonlinear fifth-order optical susceptibility in linearly absorbing liquids is established, which is related to the nonlinearity of the thermooptical coefficient and the temperature dependence of the density and heat capacity of a solvent. The quadratic recording of dynamic holograms with a diffraction efficiency of 20% is realized in ethanol solution of copper chloride.

  2. CO2-Binding-Organic-Liquids-Enhanced CO2 Capture using Polarity-Swing-Assisted Regeneration

    SciTech Connect

    Zhang, Jian; Kutnyakov, Igor; Koech, Phillip K.; Zwoster, Andy; Howard, Chris; Zheng, Feng; Freeman, Charles J.; Heldebrant, David J.

    2013-01-01

    A new solvent-based CO2 capture process couples the unique attributes of non-aqueous, CO2-binding organic liquids (CO2BOLs) with the newly discovered polarity-swing-assisted regeneration (PSAR) process that is unique to switchable ionic liquids. Laboratory measurements with PSAR indicate the ability to achieve a regeneration effect at 75°C comparable to that at 120°C using thermal regeneration only. Initial measurements also indicate that the kinetic behavior of CO2 release is also improved with PSAR. Abstract cleared PNWD-SA-9743

  3. 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

  4. Determination of 13 Organic Toxicants in Human Blood by Liquid-Liquid Extraction Coupling High-Performance Liquid Chromatography Tandem Mass Spectrometry.

    PubMed

    Song, Aiying

    2016-01-01

    Pesticides and antidepressants are frequently misused in drug-facilitated crime because of their toxicological effect and easy-availability. Therefore, it is essential for the development of a simple and reliable method for the determination of these organic toxicants in biological fluids. Here, we report on an applicable method by the combination of optimized liquid-liquid extraction (LLE) procedure and high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) to identify and quantify dimethoate, omethoate, dichlorvos, carbofuran, fenpropathrin, diazepam, estazolam, alprazolam, triazolamm, chlorpromazine, phenergan, barbitone and phenobarbital in human blood. The method demonstrated a linear calibration curve in range of 20 - 500 μg/L (r > 0.994). The accuracy evaluated by recovery spiked at three different concentrations (50, 100 and 200 μg/L) was in the range of 58.8 - 83.1% with a relative standard deviations (RSD) of 3.7 - 7.4%. The limits of quantification ranged over 6.7 - 33.3 μg/L. This method was proved to be simple and reliable, and was thus successfully applied to forensic toxicology. PMID:27302585

  5. Cationic Ionic Liquids Organic Ligands Based Metal-Organic Frameworks for Fabrication of Core-Shell Microspheres for Hydrophilic Interaction Liquid Chromatography.

    PubMed

    Dai, Qian; Ma, Junqian; Ma, Siqi; Wang, Shengyu; Li, Lijun; Zhu, Xianghui; Qiao, Xiaoqiang

    2016-08-24

    In this study, new metal-organic frameworks (MOFs) nanocrystals modified SiO2 core-shell microspheres were designed with cationic ionic liquids (ILs) 1,3-bis(4-carboxybutyl)imidazolium bromide (ILI) as organic ligands. By further adjustment the growth cycles, the new ILI-01@SiO2 core-shell stationary phase was facilely fabricated. The developed stationary phase was respectively characterized via element analysis, thermogravimetric analysis, scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectrometry. Because the introduction of cationic imidazolium-based ILs ILI for fabrication of the MOFs nanocrystals shell, the new stationary phase exhibits the retention mechanism of hydrophilic interaction liquid chromatography (HILIC). Many polar samples, such as amides, vitamins, nucleic acid bases, and nucleosides, were utilized to investigate the performance of the prepared ILI-01@SiO2 column. Compared to the conventional aminosilica column, the new ILI-01@SiO2 column displays high separation selectivity in a shorter separation time. Furthermore, the new ILI-01@SiO2 column was also used for detection of illegal melamine addition in the baby formula. All the above results demonstrate the new ILI-01@SiO2 core-shell stationary phase is of good potentials for high-selectivity separation the polar samples. PMID:27483161

  6. 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.

  7. Apparatus and methods for determining gas saturation and porosity of a formation penetrated by a gas filled or liquid filled borehole

    DOEpatents

    Wilson, Robert D.

    2001-03-27

    Methods and apparatus are disclosed for determining gas saturation, liquid saturation, porosity and density of earth formations penetrated by a well borehole. Determinations are made from measures of fast neutron and inelastic scatter gamma radiation induced by a pulsed, fast neutron source. The system preferably uses two detectors axially spaced from the neutron source. One detector is preferably a scintillation detector responsive to gamma radiation, and a second detector is preferably an organic scintillator responsive to both neutron and gamma radiation. The system can be operated in cased boreholes which are filled with either gas or liquid. Techniques for correcting all measurements for borehole conditions are disclosed.

  8. Evaluation of industrially applied heat-transfer fluids as liquid organic hydrogen carrier systems.

    PubMed

    Brückner, Nicole; Obesser, Katharina; Bösmann, Andreas; Teichmann, Daniel; Arlt, Wolfgang; Dungs, Jennifer; Wasserscheid, Peter

    2014-01-01

    Liquid organic hydrogen carrier (LOHC) systems offer a very attractive method for the decentralized storage of renewable excess energy. In this contribution, industrially well-established heat-transfer oils (typically sold under trade names, e.g., Marlotherm) are proposed as a new class of LOHC systems. It is demonstrated that the liquid mixture of isomeric dibenzyltoluenes (m.p. -39 to -34 °C, b.p. 390 °C) can be readily hydrogenated to the corresponding mixture of perhydrogenated analogues by binding 6.2 wt% of H2. The liquid H2 -rich form can be stored and transported similarly to diesel fuel. It readily undergoes catalytic dehydrogenation at temperatures above 260 °C, which proves its applicability as a reversible H2 carrier. The presented LOHC systems are further characterized by their excellent technical availability at comparably low prices, full registration of the H2 -lean forms, and excellent thermal stabilities. PMID:23956191

  9. Evaluation of industrially applied heat-transfer fluids as liquid organic hydrogen carrier systems.

    PubMed

    Brückner, Nicole; Obesser, Katharina; Bösmann, Andreas; Teichmann, Daniel; Arlt, Wolfgang; Dungs, Jennifer; Wasserscheid, Peter

    2014-01-01

    Liquid organic hydrogen carrier (LOHC) systems offer a very attractive method for the decentralized storage of renewable excess energy. In this contribution, industrially well-established heat-transfer oils (typically sold under trade names, e.g., Marlotherm) are proposed as a new class of LOHC systems. It is demonstrated that the liquid mixture of isomeric dibenzyltoluenes (m.p. -39 to -34 °C, b.p. 390 °C) can be readily hydrogenated to the corresponding mixture of perhydrogenated analogues by binding 6.2 wt% of H2. The liquid H2 -rich form can be stored and transported similarly to diesel fuel. It readily undergoes catalytic dehydrogenation at temperatures above 260 °C, which proves its applicability as a reversible H2 carrier. The presented LOHC systems are further characterized by their excellent technical availability at comparably low prices, full registration of the H2 -lean forms, and excellent thermal stabilities.

  10. Nature of Mesoscopic Organization in Protic Ionic Liquid-Alcohol Mixtures.

    PubMed

    Schroer, Wolffram; Triolo, Alessandro; Russina, Olga

    2016-03-10

    The mesoscopic morphology of mixtures of ethylammonium nitrate, a protic ionic liquid, and n-pentanol is explored for the first time using small angle X-ray scattering as a function of concentration and temperature. Both compounds are amphiphilic and characterized by an extended hydrogen bonding network; however, though macroscopically homogeneous, their mixtures are highly heterogeneous at the mesoscopic spatial scales. Previous structural studies rationalized similar features in related mixtures proposing the existence of large aggregates or micelle- and/or microemulsion-like structures. Here we show that a detailed analysis of the present concentration and temperature resolved experimental data set supports a structural scenario where the mesoscopic heterogeneities are the due to density fluctuations that are precursors of liquid-liquid phase separation. Accordingly no existence of structurally organized aggregates (such as micellar or microemulsion aggregates) is required to account for the mesoscopic heterogeneities detected in this class of binary mixtures. PMID:26895177

  11. 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.

  12. Determination of parabens in beverage samples by dispersive liquid-liquid microextraction based on solidification of floating organic droplet.

    PubMed

    Hou, Fang; Deng, Xiaoying; Jiang, Xinyu; Yu, Jingang

    2014-01-01

    A simple and efficient method for dispersive liquid-liquid microextraction of methylparaben, ethylparaben, propylparaben and butylparaben in real beverage samples was developed. It is making use of solidified floating organic droplets of 1-dodecanol which has low density and a proper melting point. Parameters influencing the extraction efficiency, such as the type of extraction and dispersive solvent, the volume of extraction and dispersive solvent, salt effect, pH, extraction time, were optimized and resulted in enrichment factors (EFs) of 84 for methylparaben, 103 for ethylparaben, 115 for propylparaben and 126 for butylparaben. The limits of detection for parabens were 1.52, 1.06, 0.32 and 0.17 ng/mL, respectively. Excellent linearity with coefficients of correlation from 0.9970 to 0.9997 was observed in the concentration range of 5-1,000 ng/mL. The repeatability of the proposed method expressed as relative standard deviations (RSDs) ranged from 2.54 to 3.89% (n = 5). The relative recoveries for parabens in beverage samples were good and in the ranges of 89.8-109.9, 90.2-107.3, 90.9-101.7 and 92.3-118.1%, respectively. Thus, the proposed method has excellent potential for the determination of parabens in beverage samples.

  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. Scintillator materials containing lanthanum fluorides

    DOEpatents

    Moses, W.W.

    1991-05-14

    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. 2 figures.

  15. Quenching correction for volumetric scintillation dosimetry of proton beams

    NASA Astrophysics Data System (ADS)

    Robertson, Daniel; Mirkovic, Dragan; Sahoo, Narayan; Beddar, Sam

    2013-01-01

    Volumetric scintillation dosimetry has the potential to provide fast, high-resolution, three-dimensional radiation dosimetry. However, scintillators exhibit a nonlinear response at the high linear energy transfer (LET) values characteristic of proton Bragg peaks. The purpose of this study was to develop a quenching correction method for volumetric scintillation dosimetry of proton beams. Scintillation light from a miniature liquid scintillator detector was measured along the central axis of a 161.6 MeV proton pencil beam. Three-dimensional dose and LET distributions were calculated for 85.6, 100.9, 144.9 and 161.6 MeV beams using a validated Monte Carlo model. LET values were also calculated using an analytical formula. A least-squares fit to the data established the empirical parameters of a quenching correction model. The light distribution in a tank of liquid scintillator was measured with a CCD camera at all four beam energies. The quenching model and LET data were used to correct the measured light distribution. The calculated and measured Bragg peak heights agreed within ±3% for all energies except 85.6 MeV, where the agreement was within ±10%. The quality of the quenching correction was poorer for sharp low-energy Bragg peaks because of blurring and detector size effects. The corrections performed using analytical LET values resulted in doses within 1% of those obtained using Monte Carlo LET values. The proposed method can correct for quenching with sufficient accuracy for dosimetric purposes. The required LET values may be computed effectively using Monte Carlo or analytical methods. Future detectors should improve blurring correction methods and optimize the pixel size to improve accuracy for low-energy Bragg peaks.

  16. Chemical Reactivity and Liquid/Nonliquid States of Secondary Organic Material.

    PubMed

    Li, Yong Jie; Liu, Pengfei; Gong, Zhaoheng; Wang, Yan; Bateman, Adam P; Bergoend, Clara; Bertram, Allan K; Martin, Scot T

    2015-11-17

    The reactivity of secondary organic material (SOM) of variable viscosity, ranging from nonliquid to liquid physical states, was studied. The SOM, produced in aerosol form from terpenoid and aromatic precursor species, was reacted with ammonia at variable relative humidity (RH). The ammonium-to-organic mass ratio (MNH4+/MOrg) increased monotonically from <5% RH to a limiting value at a threshold RH, implicating a transition from particle reactivity limited by diffusion at low RH to one limited by other factors at higher RH. For the studied size distributions and reaction times, the transition corresponded to a diffusivity above 10-17.5 ± 0.5 m2 s-1. The threshold RH values for the transition were <5% RH for isoprene-derived SOM, 35-45% RH for SOM derived from α-pinene, toluene, m-xylene, and 1,3,5-trimethylbenzene, and >90% for β-caryophyllene-derived SOM. The transition RH for reactivity differed in all cases from the transition RH of a nonliquid to a liquid state. For instance, for α-pinene-derived SOM the transition for chemical reactivity of 35-45% RH can be compared to the nonliquid to liquid transition of 65-90% RH. These differences imply that chemical transport models of atmospheric chemistry should not use the SOM liquid to nonliquid phase transition as one-to-one surrogates of SOM reactivity. PMID:26465059

  17. A novel liquid organic hydrogen carrier system based on catalytic peptide formation and hydrogenation.

    PubMed

    Hu, Peng; Fogler, Eran; Diskin-Posner, Yael; Iron, Mark A; Milstein, David

    2015-04-17

    Hydrogen is an efficient green fuel, but its low energy density when stored under high pressure or cryogenically, and safety issues, presents significant disadvantages; hence finding efficient and safe hydrogen carriers is a major challenge. Of special interest are liquid organic hydrogen carriers (LOHCs), which can be readily loaded and unloaded with considerable amounts of hydrogen. However, disadvantages include high hydrogen pressure requirements, high reaction temperatures for both hydrogenation and dehydrogenation steps, which require different catalysts, and high LOHC cost. Here we present a readily reversible LOHC system based on catalytic peptide formation and hydrogenation, using an inexpensive, safe and abundant organic compound with high potential capacity to store and release hydrogen, applying the same catalyst for loading and unloading hydrogen under relatively mild conditions. Mechanistic insight of the catalytic reaction is provided. We believe that these findings may lead to the development of an inexpensive, safe and clean liquid hydrogen carrier system.

  18. Nanolithography based on the formation and manipulation of nanometer-size organic liquid menisci.

    PubMed

    Martinez, Ramsés V; Garcia, Ricardo

    2005-06-01

    Nanometer-size menisci of organic liquids such as octane and 1-octene have been formed and used to confine chemical reactions. The application of a bias voltage between a conductive scanning probe tip separated a few nanometers from a silicon surface allows the field-induced formation of nanometer-size liquid menisci that can subsequently be used to fabricate nanometer-size structures. We report the fabrication of sub-10-nm nanostructures in 0.1 ms. Growth kinetics studies reveal that the nanostructure composition and its formation mechanism are organic-solvent-dependent. Both voltage polarities can be used to grow nanostructures, although the growth rate is significantly higher for positively biased samples. These experiments allow us to produce in the same sample two chemically different nanostructures that are easily addressed and positioned and have sub-10-nm features.

  19. A novel liquid organic hydrogen carrier system based on catalytic peptide formation and hydrogenation

    PubMed Central

    Hu, Peng; Fogler, Eran; Diskin-Posner, Yael; Iron, Mark A.; Milstein, David

    2015-01-01

    Hydrogen is an efficient green fuel, but its low energy density when stored under high pressure or cryogenically, and safety issues, presents significant disadvantages; hence finding efficient and safe hydrogen carriers is a major challenge. Of special interest are liquid organic hydrogen carriers (LOHCs), which can be readily loaded and unloaded with considerable amounts of hydrogen. However, disadvantages include high hydrogen pressure requirements, high reaction temperatures for both hydrogenation and dehydrogenation steps, which require different catalysts, and high LOHC cost. Here we present a readily reversible LOHC system based on catalytic peptide formation and hydrogenation, using an inexpensive, safe and abundant organic compound with high potential capacity to store and release hydrogen, applying the same catalyst for loading and unloading hydrogen under relatively mild conditions. Mechanistic insight of the catalytic reaction is provided. We believe that these findings may lead to the development of an inexpensive, safe and clean liquid hydrogen carrier system. PMID:25882348

  20. Application of liquid chromatography-tandem mass spectrometry in quantitative bioanalyses of organic molecules in aquatic environment and organisms.

    PubMed

    Bussy, Ugo; Li, Ke; Li, Weiming

    2016-05-01

    Analytical methods using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) for the simultaneous determination of metabolites or contaminants (or both) in various tissues of aquatic organisms and in the aquatic environment have received increasing attention in the last few years. This review discusses the findings relevant to such procedures published between 2005 and 2015. The aim is to evaluate the advantages, restrictions, and performances of the procedures from sample preparation to mass spectrometry measurement. To support these discussions, a general knowledge on LC-MS/MS is also provided. PMID:26996906

  1. First performance test of newly developed plastic scintillator for radiation detection

    NASA Astrophysics Data System (ADS)

    Watanabe, M.; Katsumata, M.; Ono, H.; Suzuki, T.; Miyata, H.; Itoh, Y.; Ishida, K.; Tamura, M.; Yamaguchi, Y.

    2015-01-01

    We present a plastic scintillator, developed in collaboration with Carlit Holdings Co., Ltd., that is fabricated using a liquid parent material cured at room temperature by adding a hardener. The new scintillator can incorporate heat-labile functional materials such as gadolinium to enhance neutron sensitivity. The characteristics of the new scintillator, in particular the light yield and attenuation length, were evaluated using a 90Sr β-ray source. The light yield was measured 7% Anthracene on the basis of a comparison with commercially available scintillator (BC-408) at a distance of 18 cm from the photodetector surface. This light yield is dependent on the distance between the luminous point and the photodetector because of light attenuation. The attenuation length of the Gd-doped scintillator was about 50 cm.

  2. Fast, non-linear optical-scattering spectroscopy in shock-compressed organic liquids

    SciTech Connect

    Schmidt, S.C.; Moore, D.S.; Schiferl, D.; Shaner, J.W.

    1983-01-01

    Nanosecond stimulated Raman and coherent anti-Stokes Raman scattering spectroscopy have been used to determine molecular vibrational frequency shifts and changes of phase in shock-compressed organic liquids. Results of dynamic experiments are compared to static Raman scattering measurements of samples, compressed and heated in a diamond-anvil cell. Objectives of the experiments are to determine the molecular structure and ultimately the energy transfer mechanisms in shock-compressed condensed phase materials.

  3. Technical Assessment of Organic Liquid Carrier Hydrogen Storage Systems for Automotive Applications

    SciTech Connect

    Ahluwalia, R. K.; Hua, T. Q.; Peng, J. -K; Kromer, M.; Lasher, S.; McKenney, K.; Law, K.; Sinha, J.

    2011-06-21

    In 2007-2009, the DOE Hydrogen Program conducted a technical assessment of organic liquid carrier based hydrogen storage systems for automotive applications, consistent with the Program’s Multiyear Research, Development, and Demonstration Plan. This joint performance (ANL) and cost analysis (TIAX) report summarizes the results of this assessment. These results should be considered only in conjunction with the assumptions used in selecting, evaluating, and costing the systems discussed here and in the Appendices.

  4. 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.

  5. 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.

  6. Parameterizing liquid crystal variable retarder structural organization with a fractal-Born approximation model

    NASA Astrophysics Data System (ADS)

    Gladish, James C.; Duncan, Donald D.

    2016-05-01

    Liquid crystal variable retarders (LCVRs) are computer-controlled birefringent devices that contain nanometer-sized birefringent liquid crystals (LCs). These devices impart retardance effects through a global, uniform orientation change of the LCs, which is based on a user-defined drive voltage input. In other words, the LC structural organization dictates the device functionality. The LC structural organization also produces a spectral scatter component which exhibits an inverse power law dependence. We investigate LC structural organization by measuring the voltage-dependent LC spectral scattering signature with an integrating sphere and then relate this observable to a fractal-Born model based on the Born approximation and a Von Kármán spectrum. We obtain LCVR light scattering spectra at various drive voltages (i.e., different LC orientations) and then parameterize LCVR structural organization with voltage-dependent correlation lengths. The results can aid in determining performance characteristics of systems using LCVRs and can provide insight into interpreting structural organization measurements.

  7. Capabilities and limitations of dispersive liquid-liquid microextraction with solidification of floating organic drop for the extraction of organic pollutants from water samples.

    PubMed

    Vera-Avila, Luz E; Rojo-Portillo, Tania; Covarrubias-Herrera, Rosario; Peña-Alvarez, Araceli

    2013-12-17

    Dispersive liquid-liquid microextraction with solidification of floating organic drop (DLLME-SFO) is one of the most interesting sample preparation techniques developed in recent years. Although several applications have been reported, the potentiality and limitations of this simple and rapid extraction technique have not been made sufficiently explicit. In this work, the extraction efficiency of DLLME-SFO for pollutants from different chemical families was determined. Studied compounds include: 10 polycyclic aromatic hydrocarbons, 5 pesticides (chlorophenoxy herbicides and DDT), 8 phenols and 6 sulfonamides, thus, covering a large range of polarity and hydrophobicity (LogKow 0-7, overall). After optimization of extraction conditions using 1-dodecanol as extractant, the procedure was applied for extraction of each family from 10-mL spiked water samples, only adjusting sample pH as required. Absolute recoveries for pollutants with LogKow 3-7 were >70% and recovery values within this group (18 compounds) were independent of structure or hydrophobicity; the precision of recovery was very acceptable (RSD<12%) and linear behavior was observed in the studied concentration range (r(2)>0.995). Extraction recoveries for pollutants with LogKow 1.46-2.8 were in the range 13-62%, directly depending on individual LogKow values; however, good linearity (r(2)>0.993) and precision (RSD<6.5%) were also demonstrated for these polar solutes, despite recovery level. DLLME-SFO with 1-dodecanol completely failed for extraction of compounds with LogKow≤1 (sulfa drugs), other more polar extraction solvents (ionic liquids) should be explored for highly hydrophilic pollutants.

  8. Insights into Mechanistic Models for Evaporation of Organic Liquids in the Environment Obtained by Position-Specific Carbon Isotope Analysis.

    PubMed

    Julien, Maxime; Nun, Pierrick; Robins, Richard J; Remaud, Gérald S; Parinet, Julien; Höhener, Patrick

    2015-11-01

    Position-specific isotope effects (PSIEs) have been measured by isotope ratio monitoring (13)C nuclear magnetic resonance spectrometry during the evaporation of 10 liquids of different polarities under 4 evaporation modes (passive evaporation, air-vented evaporation, low pressure evaporation, distillation). The observed effects are used to assess the validity of the Craig-Gordon isotope model for organic liquids. For seven liquids the overall isotope effect (IE) includes a vapor-liquid contribution that is strongly position-specific in polar compounds but less so in apolar compounds and a diffusive IE that is not position-specific, except in the alcohols, ethanol and propan-1-ol. The diffusive IE is diminished under forced evaporation. The position-specific isotope pattern created by liquid-vapor IEs is manifest in five liquids, which have an air-side limitation for volatilization. For the alcohols, undefined processes in the liquid phase create additional PSIEs. Three other liquids with limitations on the liquid side have a lower, highly position-specific, bulk diffusive IE. It is concluded that evaporation of organic pollutants creates unique position-specific isotope patterns that may be used to assess the progress of remediation or natural attenuation of pollution and that the Craig-Gordon isotope model is valid for the volatilization of nonpolar organic liquids with air-side limitation of the volatilization rate.

  9. 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.

  10. Ionospheric Scintillation Effects on GPS

    NASA Astrophysics Data System (ADS)

    Steenburgh, R. A.; Smithtro, C.; Groves, K.

    2007-12-01

    . Ionospheric scintillation of Global Positioning System (GPS) signals threatens navigation and military operations by degrading performance or making GPS unavailable. Scintillation is particularly active, although not limited to, a belt encircling the earth within 20 degrees of the geomagnetic equator. As GPS applications and users increases, so does the potential for detrimental impacts from scintillation. We examined amplitude scintillation data spanning seven years from Ascension Island, U.K.; Ancon, Peru; and Antofagasta, Chile in the Atlantic/Americas longitudinal sector at as well as data from Parepare, Indonesia; Marak Parak, Malaysia; Pontianak, Indonesia; Guam; and Diego Garcia, U.K.; in the Pacific longitudinal sector. From these data, we calculate percent probability of occurrence of scintillation at various intensities described by the S4 index. Additionally, we determine Dilution of Precision at one minute resolution. We examine diurnal, seasonal and solar cycle characteristics and make spatial comparisons. In general, activity was greatest during the equinoxes and solar maximum, although scintillation at Antofagasta, Chile was higher during 1998 rather than at solar maximum.

  11. Determination of regulatory organic compounds in radioactive waste samples. Semivolatile organics in aqueous liquids

    SciTech Connect

    Tomkins, B.A.; Caton, J.E. Jr.; Fleming, G.S.; Garcia, M.E.; Harmon, S.H.; Schenley, R.L.; Treese, C.A.; Griest, W.H. )

    1990-02-01

    The regulatory semivolatile organic compounds present in radioactive aqueous waste samples are extracted and concentrated in a small-scale version of a standard EPA procedure normally used for ground waters. Decontamination is sufficient to permit analysis of the extract in a conventional gas chromatography/mass spectrometry laboratory. The performance of the modified procedure, based on surrogate standards, matrix spikes and matrix spike duplicates, and blanks, is comparable to that of the standard method. The modified procedure was applied to a variety of aqueous radioactive waste tank samples. Only 12 of the EPA Appendix VIII compounds were present, and none in concentrations exceeding the reporting limit (500 or 2,500 {mu}g/L). The most common semivolatile present was tributyl phosphate, an organic extractant commonly used in radiochemical processing, at 2,000-30,000 {mu}g/L.

  12. 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.

  13. Chromatographic behavior of small organic compounds in low-temperature high-performance liquid chromatography using liquid carbon dioxide as the mobile phase.

    PubMed

    Motono, Tomohiro; Nagai, Takashi; Kitagawa, Shinya; Ohtani, Hajime

    2015-07-01

    Low-temperature high-performance liquid chromatography, in which a loop injector, column, and detection cell were refrigerated at -35ºC, using liquid carbon dioxide as the mobile phase was developed. Small organic compounds (polyaromatic hydrocarbons, alkylbenzenes, and quinones) were separated by low-temperature high-performance liquid chromatography at temperatures from -35 to -5ºC. The combination of liquid carbon dioxide mobile phase with an octadecyl-silica (C18 ) column provided reversed phase mode separation, and a bare silica-gel column resulted in normal phase mode separation. In both the cases, nonlinear behavior at approximately -15ºC was found in the relationship between the temperature and the retention factors of the analytes (van't Hoff plots). In contrast to general trends in high-performance liquid chromatography, the decrease in temperature enhanced the separation efficiency of both the columns.

  14. 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.

  15. Ionic liquids as an electrolyte for the electro synthesis of organic compounds.

    PubMed

    Kathiresan, Murugavel; Velayutham, David

    2015-12-25

    The use of ionic liquids (ILs) as a solvent and an electrolyte for electro organic synthesis has been reviewed. To date several ILs exist, however the ILs based on tetraalkylammonium, pyrrolidinium, piperidinium and imidazolium cations with BF4(-), PF6(-), and TFSI anions have been widely used and explored the most. Electro organic synthesis in ionic liquid media leading to the synthesis of a wide range of organic compounds has been discussed. Anodic oxidation or cathodic reduction will generate radical cation or anion intermediates, respectively. These radicals can undergo self coupling or coupling with other molecules yielding organic compounds of interest. The cation of the IL is known to stabilize the radical anion extensively. This stabilization effect has a specific impact on the electrochemical CO2 reduction and coupling to various organics. The relative stability of the intermediates in IL leads to the formation of specific products in higher yields. Electrochemical reduction of imidazolium or thiazolium based ILs generates N-heterocyclic carbenes that have been shown to catalyze a wide range of base or nucleophile catalyzed organic reactions in IL media, an aspect that falls into the category of organocatalysis. Electrochemical fluorination or selective electrochemical fluorination is another fascinating area that delivers selectively fluorinated organic products in Et3N·nHF or Et4NF·nHF adducts (IL) via anodic oxidation. Oxidative polymerization in ILs has been explored the most; although morphological changes were observed compared to the conventional methods, polymers were obtained in good yields and in some cases ILs were used as dopants to improve the desired properties.

  16. Pyrolysis characteristics and pyrolysis products separation for recycling organic materials from waste liquid crystal display panels.

    PubMed

    Wang, Ruixue; Xu, Zhenming

    2016-01-25

    Waste liquid crystal display (LCD) panels mainly contain inorganic materials (glass substrate with indium-tin oxide film), and organic materials (polarizing film and liquid crystal). The organic materials should be removed beforehand since the organic matters would hinder the indium recycling process. In the present study, pyrolysis process is used to remove the organic materials and recycle acetic as well as and triphenyl phosphate (TPP) from waste LCD panels in an environmental friendly way. Several highlights of this study are summarized as follows: (i) Pyrolysis characteristics and pyrolysis kinetics analysis are conducted which is significant to get a better understanding of the pyrolysis process. (ii) Optimum design is developed by applying Box-Behnken Design (BBD) under response surface methodology (RSM) for engineering application which is significant to guide the further industrial recycling process. The oil yield could reach 70.53 wt% and the residue rate could reach 14.05 wt% when the pyrolysis temperature is 570 °C, nitrogen flow rate is 6 L min(-1) and the particle size is 0.5 mm. (iii) Furthermore, acetic acid and TPP are recycled, and then separated by rotary evaporation, which could reduce the consumption of fossil energy for producing acetic acid, and be reused in electronics manufacturing industry.

  17. Retention-oxidation-adsorption process for emergent treatment of organic liquid spills.

    PubMed

    Liu, Xianjun; Li, Yu; Zhang, Xingwang; Lei, Lecheng

    2011-11-15

    The feasibility and effectiveness of retention-oxidation-adsorption process (ROA) for the elimination of organic contaminants induced by chemical accidents were investigated in this study. Organobentonites (DTMA-, TTA-, CTMA- and OTMA-bentonite), potassium ferrate (Fe(VI)), ozone and granular activated carbon (GAC) were used as rapid and efficient materials in the treatment and recovery of organic liquid spills. Results indicated that the retention capacities of organobentonites (especially CTMA-bentonite) were much higher than that of natural bentonite towards the chosen organic compounds. Additionally, pH, oxidant dosage, initial concentration of contaminant and chemical structure had significant influences on the effectiveness of the oxidation process. In a pilot-scale experiment, the ferrate/GAC (F/G) and ozone/GAC (O/G) processes made a comparatively good performance in the treatment of wastewater containing aniline or nitrobenzene, with the removal efficiencies of the contaminants greater than 80%. Overall, the ROA process showed a high efficiency and steady operation in the removal of hazardous organic liquids and subsequent clean up of the contaminated site.

  18. Membrane separation in green chemical processing: solvent nanofiltration in liquid phase organic synthesis reactions.

    PubMed

    Livingston, Andrew; Peeva, Ludmila; Han, Shejiao; Nair, Dinesh; Luthra, Satinder Singh; White, Lloyd S; Freitas Dos Santos, Luisa M

    2003-03-01

    This paper describes ideas together with preliminary experimental results for applying solvent nanofiltration to liquid phase organic synthesis reactions. Membranes for organic solvent nanofiltration have only recently (during the 1990s) become available and, to date, have been applied primarily to food processing (vegetable oil processing, in particular) and refinery processes. Applications to organic synthesis, even at a laboratory feasibility level, are few. However, these membranes have great potential to improve the environmental performance of many liquid phase synthesis reactions by reducing the need for complex solvent handling operations. Examples that are shown to be feasible are solvent exchanges, where it is desired to swap a high molecular weight molecule from one solvent to another between separate stages in a complex synthesis, and recycle and reuse of homogeneous catalysts. In solvent exchanges, nanofiltration is shown to provide a fast and effective means of swapping from a high boiling point solvent to a solvent with a lower boiling point-this is a difficult operation by means of distillation. Solvent nanofiltration is shown to be able to separate two distinct types of homogeneous catalysts, phase transfer catalysts and organometallic catalysts, from their respective reaction products. In both cases the application of organic solvent nanofiltration allows several reuses of the same catalyst. Catalyst stability is shown to be an essential requirement for this technique to be effective. Finally, we present a discussion of scale-up aspects including membrane flux and process economics.

  19. Pyrolysis characteristics and pyrolysis products separation for recycling organic materials from waste liquid crystal display panels.

    PubMed

    Wang, Ruixue; Xu, Zhenming

    2016-01-25

    Waste liquid crystal display (LCD) panels mainly contain inorganic materials (glass substrate with indium-tin oxide film), and organic materials (polarizing film and liquid crystal). The organic materials should be removed beforehand since the organic matters would hinder the indium recycling process. In the present study, pyrolysis process is used to remove the organic materials and recycle acetic as well as and triphenyl phosphate (TPP) from waste LCD panels in an environmental friendly way. Several highlights of this study are summarized as follows: (i) Pyrolysis characteristics and pyrolysis kinetics analysis are conducted which is significant to get a better understanding of the pyrolysis process. (ii) Optimum design is developed by applying Box-Behnken Design (BBD) under response surface methodology (RSM) for engineering application which is significant to guide the further industrial recycling process. The oil yield could reach 70.53 wt% and the residue rate could reach 14.05 wt% when the pyrolysis temperature is 570 °C, nitrogen flow rate is 6 L min(-1) and the particle size is 0.5 mm. (iii) Furthermore, acetic acid and TPP are recycled, and then separated by rotary evaporation, which could reduce the consumption of fossil energy for producing acetic acid, and be reused in electronics manufacturing industry. PMID:26444486

  20. Ionic Liquids Beyond Simple Solvents: Glimpses at the State of the Art in Organic Chemistry

    PubMed Central

    Kuchenbuch, Andrea

    2015-01-01

    Abstract Within the last 25 years ionic liquids have written a tremendous success story, which is documented in a nearly uncountable amount of original research papers, reviews, and numerous applications in research and industry. These days, ionic liquids can be considered as a mature class of compounds for many different applications. Frequently, they are used as neoteric solvents for chemical tansformations, and the number of reviews on this field of research is huge. In this focused review, though, we are trying to evaluate the state of the art of ionic liquid chemistry beyond using them simply as solvents for chemical transformations. It is not meant to be a comprehensive overview on the topic; the choice of emphasis and examples rather refects the authors’ personal view on the field. We are especially highlighting fields in which we believe the most fundamental developments within the next five years will take place: biomass processing, (chiral) ionic liquids from natural sources, biotransformations, and organic synthesis. PMID:27308192

  1. Improved solvent collection system for a dispersive liquid-liquid microextraction of organochlorine pesticides from water using low-density organic solvent.

    PubMed

    Chang, Chu-Chi; Wei, Shuo-Yang; Huang, Shang-Da

    2011-04-01

    In this study, the organochlorine pesticides (OCPs) levels in lake and tap water samples were determined by a dispersive liquid-liquid microextraction method using a low-density organic solvent and an improved solvent collection system (DLLME-ISCS). This method used a very small volume of a solvent of low toxicity (11  μL of 1-nonanol and 400  μL of methanol) to extract OCPs from 10  mL water samples prior to the analysis by GC. After centrifugation in the dispersive liquid-liquid microextraction, there was a liquid organic drop floating between the water surface and the glass wall of the centrifuge tube. The liquid organic drop (with some water phase) was transferred into a microtube (3  mm×15  mm) with a syringe. The organic and aqueous phases were separated in the microtube immediately. Then, 1  μL of the organic solvent (which was in the upper portion of liquid in the microtube) was easily collected by a syringe and injected into the GC-ECD system for the analysis. Under optimum conditions, the linear range of this method was 5-5000  ng/L for most of the analytes. The correlation coefficient was higher than 0.997. Enrichment factors ranged from 1309 to 3629. The relative recoveries ranged from 73 to 119% for lake water samples. The LODs of the method ranged from 0.7 to 9.4  ng/L. The precision of the method ranged from 1.0 to 10.8% for lake water.

  2. Fast-freezing with liquid nitrogen preserves bulk dissolved organic matter concentrations, but not its composition

    NASA Astrophysics Data System (ADS)

    Thieme, Lisa; Graeber, Daniel; Kaupenjohann, Martin; Siemens, Jan

    2016-08-01

    Freezing can affect concentrations and spectroscopic properties of dissolved organic matter (DOM) in water samples. Nevertheless, water samples are regularly frozen for sample preservation. In this study we tested the effect of different freezing methods (standard freezing at -18 °C and fast-freezing with liquid nitrogen) on DOM concentrations measured as organic carbon (DOC) concentrations and on spectroscopic properties of DOM from different terrestrial ecosystems (forest and grassland). Fresh and differently frozen throughfall, stemflow, litter leachate and soil solution samples were analyzed for DOC concentrations, UV-vis absorption and fluorescence excitation-emission matrices combined with parallel factor analysis (PARAFAC). Fast-freezing with liquid nitrogen prevented a significant decrease of DOC concentrations observed after freezing at -18 °C. Nonetheless, the share of PARAFAC components 1 (EXmax < 250 nm (340 nm), EXmax: 480 nm) and 2 (EXmax: 335 nm, EXmax: 408 nm) to total fluorescence and the humification index (HIX) decreased after both freezing treatments, while the shares of component 3 (EXmax: < 250 nm (305 nm), EXmax: 438 nm) as well as SUVA254 increased. The contribution of PARAFAC component 4 (EXmax: 280 nm, EXmax: 328 nm) to total fluorescence was not affected by freezing. We recommend fast-freezing with liquid nitrogen for preservation of bulk DOC concentrations of samples from terrestrial sources, whereas immediate measuring is preferable to preserve spectroscopic properties of DOM.

  3. The electro-structural behaviour of yarn-like carbon nanotube fibres immersed in organic liquids

    NASA Astrophysics Data System (ADS)

    Terrones, Jeronimo; Windle, Alan H.; Elliott, James A.

    2014-10-01

    Yarn-like carbon nanotube (CNT) fibres are a hierarchically-structured material with a variety of promising applications such as high performance composites, sensors and actuators, smart textiles, and energy storage and transmission. However, in order to fully realize these possibilities, a more detailed understanding of their interactions with the environment is required. In this work, we describe a simplified representation of the hierarchical structure of the fibres from which several mathematical models are constructed to explain electro-structural interactions of fibres with organic liquids. A balance between the elastic and surface energies of the CNT bundle network in different media allows the determination of the maximum lengths that open junctions can sustain before collapsing to minimize the surface energy. This characteristic length correlates well with the increase of fibre resistance upon immersion in organic liquids. We also study the effect of charge accumulation in open interbundle junctions and derive expressions to describe experimental data on the non-ohmic electrical behaviour of fibres immersed in polar liquids. Our analyses suggest that the non-ohmic behaviour is caused by progressively shorter junctions collapsing as the voltage is increased. Since our models are not based on any property unique to carbon nanotubes, they should also be useful to describe other hierarchical structures.

  4. Wetting in color: colorimetric differentiation of organic liquids with high selectivity.

    PubMed

    Burgess, Ian B; Koay, Natalie; Raymond, Kevin P; Kolle, Mathias; Lončar, Marko; Aizenberg, Joanna

    2012-02-28

    Colorimetric litmus tests such as pH paper have enjoyed wide commercial success due to their inexpensive production and exceptional ease of use. Expansion of colorimetry to new sensing paradigms is challenging because macroscopic color changes are seldom coupled to arbitrary differences in the physical/chemical properties of a system. Here we present in detail the design of a "Wetting In Color Kit" (WICK), an inexpensive and highly selective colorimetric indicator for organic liquids that exploits chemically encoded inverse-opal photonic crystals to project minute differences in liquids' wettability to macroscopically distinct, easy-to-visualize structural color patterns. We show experimentally and corroborate with theoretical modeling using percolation theory that the highly symmetric structure of our large-area, defect-free SiO(2) inverse-opal films leads to sharply defined threshold wettability for liquid infiltration, occurring at intrinsic contact angles near 20° with an estimated resolution smaller than 5°. The regular structure also produces a bright iridescent color, which disappears when infiltrated with liquid, naturally coupling the optical and fluidic responses. To deterministically design a WICK that differentiates a broad range of liquids, we introduced a nondestructive quality control procedure to regulate the pore structure and developed two new surface modification protocols, both requiring only silanization and selective oxidation. The resulting tunable, built-in horizontal and vertical chemistry gradients let us tailor the wettability threshold to specific liquids across a continuous range. With patterned oxidation as a final step, we control the shape of the liquid-specific patterns displayed, making WICK easier to read. Using these techniques, we demonstrate the applicability of WICKs in several exemplary systems that colorimetrically distinguish (i) ethanol-water mixtures varying by only 2.5% in concentration; (ii) methanol, ethanol, and

  5. Direct Observation of Self-Organized Water-Containing Structures in the Liquid Phase and Their Influence on 5-(Hydroxymethyl)furfural Formation in Ionic Liquids.

    PubMed

    Kashin, Alexey S; Galkin, Konstantin I; Khokhlova, Elena A; Ananikov, Valentine P

    2016-02-01

    Water-containing organic solutions are widespread reaction media in organic synthesis and catalysis. This type of multicomponent liquid system has a number of unique properties because of the tendency for water to self-organize in mixtures with other liquids. The characterization of these water domains is a challenging task because of their soft and dynamic nature. In the present study, the morphology and dynamics of micrometer- and nanometer-scale water-containing compartments in ionic liquids were directly observed by electron microscopy. A variety of morphologies, including isolated droplets, dense structures, aggregates, and 2D meshworks, have been experimentally detected and studied. Using the developed method, the impact of water on the acid-catalyzed biomass conversion reaction was studied at the microscopic level. The process that produced nanostructured domains in solution led to better yields and higher selectivities compared with reactions involving the bulk system. PMID:26754786

  6. Compositional Effects on Interfacial Properties in Contaminated Systems: Implications for Organic Liquid Migration and Recovery

    SciTech Connect

    Abriola, Linda M.; Demond, Avery H.; Hsu, Hsin-lan; O'Carroll, Denis M.; Phelan, Thoams, J.; Polityka, Catherine A.; Ryder, Jodi L.

    2003-03-27

    An understanding of the transport behavior of dense non-aqueous phase organic liquids (DNAPLs) is a prerequisite for the accurate assessment of chemical exposure and the design of effective subsurface remediation strategies. This paper highlights results of an ongoing EMSP research project designed to explore the influence of solid and organic phase composition on DNAPL migration, entrapment and recovery from contaminated aquifers. The integrated research program includes small-scale laboratory investigations to examine the dependence of organic contaminant constitutive relationships (e.g., capillary pressure-saturation, relative permeability, residual saturation and interphase mass transfer rates) on interfacial properties. Models developed from these observations are being incorporated into a compositional multiphase simulator to facilitate prediction of DNAPL behavior under conditions representative of field sites. Two-dimensional sand box experiments are also being undertaken to validate the modeling approach. Results from this research demonstrate the dramatic influence of interfacial property variation on DNAPL migration and retention.

  7. LABORATORY INVESTIGATION OF RESIDUAL LIQUID ORGANICS FROM SPILLS, LEAKS, AND THE DISPOSAL OF HAZARDOUS WASTES IN GROUNDWATER

    EPA Science Inventory

    Organic liquids that are essentially immiscible with water migrate through the subsurface through the influence of capillary, viscous and buoyancy forces. Four experimental methods were employed. First, quantitative displacement experiments using short soil columns; second, add...

  8. 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.

  9. New metal-organic nanomaterials synthesized by laser irradiation of organic liquids

    NASA Astrophysics Data System (ADS)

    Kuzmin, Stanislav L.; Wesolowski, Michal J.; Duley, Walter W.

    2014-03-01

    A new type of metal-organic composition consisting of clusters of nanoparticles has been synthesised by laser irradiation of metallocene/benzene solutions. The metallocene molecules in this reaction become the source of the metal. Exposure to high-energy femtosecond laser pulses dehydrogenate benzene molecules and initiate the high-temperature high-pressure conditions that results in the synthesis of new materials. Irradiation experiments have been carried out on ferrocene/benzene and on other solutions. With ferrocene the synthesis of a new compound has been confirmed by X-ray powder diffraction as the peaks detected do not correspond to any known substance in the Crystallography Open Database. Theoretical simulation of the periodic structure of this new carbide predicts that it has hexagonal symmetry and a unit cell with a = 3.2A and c =2.8A. The exact structure is still uncertain but may be determined from scanning tunneling microscope (STM) studies.

  10. New metal-organic nanomaterials synthesized by laser irradiation of organic liquids

    SciTech Connect

    Kuzmin, Stanislav L.; Wesolowski, Michal J.; Duley, Walter W.

    2014-03-31

    A new type of metal-organic composition consisting of clusters of nanoparticles has been synthesised by laser irradiation of metallocene/benzene solutions. The metallocene molecules in this reaction become the source of the metal. Exposure to high-energy femtosecond laser pulses dehydrogenate benzene molecules and initiate the high-temperature high-pressure conditions that results in the synthesis of new materials. Irradiation experiments have been carried out on ferrocene/benzene and on other solutions. With ferrocene the synthesis of a new compound has been confirmed by X-ray powder diffraction as the peaks detected do not correspond to any known substance in the Crystallography Open Database. Theoretical simulation of the periodic structure of this new carbide predicts that it has hexagonal symmetry and a unit cell with a = 3.2A and c =2.8A. The exact structure is still uncertain but may be determined from scanning tunneling microscope (STM) studies.

  11. CO2-binding Organic Liquids, an Integrated Acid Gas Capture System

    SciTech Connect

    Heldebrant, David J; Koech, Phillip K; Rainbolt, James E; Zheng, Feng

    2011-04-01

    Amine systems are effective for CO2 capture, but they are still inefficient because the solvent regeneration energy is largely defined by the amount of water in the process. Most amines form heat-stable salts with SO2 and COS resulting in parasitic solvent loss and degradation. Stripping the CO2-rich solvent is energy intensive it requires temperatures above 100 °C due to the high specific heat and heat of vaporization of water. CO2-capture processes could be much more energy efficient in a water free amine process. In addition, if the capture-material is chemically compatible with other acid gases, less solvent would be lost to heat-stable salts and the process economics would be further improved. One such system that can address these concerns is Binding Organic Liquids (BOLs), a class of switchable ionic liquids.

  12. Nature-inspired light-harvesting liquid crystalline porphyrins for organic photovoltaics

    SciTech Connect

    Li, Lanfang; Kang, Shin-Woong; Harden, John; Sun, Qingjiang; Zhou, Xiaoli; Dai, Liming; Jakli, Antal; Kumar, Satyendra; Li, Quan

    2008-12-22

    A new class of nanoscale light-harvesting discotic liquid crystalline porphyrins, with the same basic structure of the best photoreceptor in nature (chlorophyll), was synthesized. These materials can be exceptionally aligned into a highly ordered architecture in which the columns formed by intermolecular {pi}-{pi} stacking are spontaneously perpendicular to the substrate. The homeotropic alignment, well confirmed by synchrotron X-ray diffraction, could not only provide the most efficient pathway for hole conduction along the columnar axis crossing the device thickness, but also offer the largest area to the incident light for optimized light harvesting. Their preliminary photocurrent generation and photovoltaic performances were also demonstrated. The results provide new and efficient pathways to the development of organic photovoltaics by using homeotropically aligned liquid crystal thin films.

  13. Self-organization processes and topological defects in nanolayers in a nematic liquid crystal

    SciTech Connect

    Chuvyrov, A. N.; Girfanova, F. M. Mal'tsev, I. S.

    2008-05-15

    Atomic force microscopy is used to study the self-organization processes that occur during the formation of topological defects in nanomolecular layers in a nematic liquid crystal with the homeotropic orientation of its molecules with respect to the substrate. In this case, a smectic monolayer with a thickness of one molecule length (about 2.2 nm) forms on the substrate, and a nanomolecular layer of a nematic liquid crystal forms above this monolayer. In such virtually two-dimensional layers, numerous different nanoclusters, namely, hut structures, pyramids, raft structures with symmetry C{sub nm} (where n = 2, 4, 5, 6, 7, ?, {infinity}), cones, and nanopools, form [1]. They have a regular shape close to the geometry of solid crystals. Modulated linear structures and topological point defects appear spontaneously in the nanopools and raft structures.

  14. Photogeneration and enhanced charge transport in aligned smectic liquid crystalline organic semiconductor

    SciTech Connect

    Paul, Sanjoy; Ellman, Brett; Tripathi, Suvagata; Twieg, Robert J.

    2015-10-07

    Liquid crystalline organic semiconductors are emerging candidates for applications in electronic and photonic devices. One of the most attractive aspects of such materials is the potential, in principle, to easily control and manipulate the molecular alignment of the semiconductor over large length scales. Here, we explore the consequences of alignment in a model smectic liquid crystalline semiconductor, and find that the photogeneration efficiency is a strong function of incident polarization in aligned samples. A straightforward theory shows that such behavior is a general feature of aligned materials, regardless of the details of photophysics. Furthermore, we uncover tentative evidence that the mobility of aligned samples is substantially enhanced. Both of these phenomena are of significant technological importance.

  15. Aza-crown ether complex cation ionic liquids: preparation and applications in organic reactions.

    PubMed

    Song, Yingying; Cheng, Chen; Jing, Huanwang

    2014-09-26

    Aza-crown ether complex cation ionic liquids (aCECILs) were devised, fabricated, and characterized by using NMR spectroscopy, MS, thermogravimetric differential thermal analysis (TG-DTA), elemental analysis and physical properties. These new and room-temperature ILs were utilized as catalysts in various organic reactions, such as the cycloaddition reaction of CO2 to epoxides, esterification of acetic acid and alcohols, the condensation reaction of aniline and propylene carbonate, and Friedel-Crafts alkylation of indole with aldehydes were investigated carefully. In these reactions, the ionic liquid exhibited cooperative catalytic activity between the anion and cation. In addition, the aza-[18-C-6HK][HSO4]2 was the best acidic catalyst in the reactions of esterification and Friedel-Crafts alkylation under mild reaction conditions. PMID:25154312

  16. Formation of Organic Peroxides and Ethers at Post-Discharge Plasma Plume-Liquid Interfaces

    NASA Astrophysics Data System (ADS)

    Begliarbekov, Milan; Kotowich, Steven; Tarnovsky, Vladimir

    2009-03-01

    A direct current (DC) micro-hollow cathode plasma source operating in a mixed glow-streamer regime was used to generate an atmospheric pressure N2 discharge. The post-discharge plume / afterglow was interfaced with a target liquid-phase solution, and caused a change in the chemistry of the target solution. In the present work we study the interaction of an N2 plume with a mixture of 2-methyl-1-propanol and hexane, which results in the formation of organic peroxides and ethers at the plume-liquid interface. The presence of the peroxide and ether functional groups is established by ^1H-NMR, FTIR, and Raman spectra of the reaction products. Fast Atom Bombardment (FAB) mass spectrometry is also used to further characterize the reaction products.

  17. Aza-crown ether complex cation ionic liquids: preparation and applications in organic reactions.

    PubMed

    Song, Yingying; Cheng, Chen; Jing, Huanwang

    2014-09-26

    Aza-crown ether complex cation ionic liquids (aCECILs) were devised, fabricated, and characterized by using NMR spectroscopy, MS, thermogravimetric differential thermal analysis (TG-DTA), elemental analysis and physical properties. These new and room-temperature ILs were utilized as catalysts in various organic reactions, such as the cycloaddition reaction of CO2 to epoxides, esterification of acetic acid and alcohols, the condensation reaction of aniline and propylene carbonate, and Friedel-Crafts alkylation of indole with aldehydes were investigated carefully. In these reactions, the ionic liquid exhibited cooperative catalytic activity between the anion and cation. In addition, the aza-[18-C-6HK][HSO4]2 was the best acidic catalyst in the reactions of esterification and Friedel-Crafts alkylation under mild reaction conditions.

  18. Improved Scintillator Materials for Compact Electron Antineutrino Detectors

    SciTech Connect

    Dijkstra, Peter; Wortche, Heinrich J.; Browne, Wesley R.

    2011-04-27

    Developments in the fields of chemistry and materials science provide new components that hold the potential to improve the performance of liquid scintillation electron antineutrino detectors used for the monitoring of nuclear reactors. New compounds can provide for more efficient, stable, and safer operation of these detectors. Current detectors and their detector materials raise issues regarding size, quantum efficiency, stability, and spatial resolution for the vertex detection. For compact detectors (1 m{sup 3} active volume) improvement of these issues with existing liquid scintillation cocktails can be obtained by means of developing stable and efficient neutron capture agents. These agents comprise of boron or lithium containing coordination compounds, in addition advances in fluorescence detection technologies and optimization of solvent characteristics can improve the overall efficiency. Focus points of the new detector material design are to enable a compact, robust, and direction sensitive electron antineutrino detector.

  19. Study of nanostructural organization of ionic liquids by electron paramagnetic resonance spectroscopy.

    PubMed

    Merunka, Dalibor; Peric, Mirna; Peric, Miroslav

    2015-02-19

    The X-band electron paramagnetic resonance spectroscopy (EPR) of a stable, spherical nitroxide spin probe, perdeuterated 2,2,6,6-tetramethyl-4-oxopiperidine-1-oxyl (pDTO) has been used to study the nanostructural organization of a series of 1-alkyl-3-methylimidazolium tetrafluoroborate ionic liquids (ILs) with alkyl chain lengths from two to eight carbons. By employing nonlinear least-squares fitting of the EPR spectra, we have obtained values of the rotational correlation time and hyperfine coupling splitting of pDTO to high precision. The rotational correlation time of pDTO in ILs and squalane, a viscous alkane, can be fit very well to a power law functionality with a singular temperature, which often describes a number of physical quantities measured in supercooled liquids. The viscosity of the ILs and squalane, taken from the literature, can also be fit to the same power law expression, which means that the rotational correlation times and the ionic liquid viscosities have similar functional dependence on temperature. The apparent activation energy of both the rotational correlation time of pDTO and the viscous flow of ILs and squalane increases with decreasing temperature; in other words, they exhibit strong non-Arrhenius behavior. The rotational correlation time of pDTO as a function of η/T, where η is the shear viscosity and T is the temperature, is well described by the Stokes-Einstein-Debye (SED) law, while the hydrodynamic probe radii are solvent dependent and are smaller than the geometric radius of the probe. The temperature dependence of hyperfine coupling splitting is the same in all four ionic liquids. The value of the hyperfine coupling splitting starts decreasing with increasing alkyl chain length in the ionic liquids in which the number of carbons in the alkyl chain is greater than four. This decrease together with the decrease in the hydrodynamic radius of the probe indicates a possible existence of nonpolar nanodomains.

  20. Ionic liquid assisted hydrothermal fabrication of hierarchically organized γ-AlOOH hollow sphere

    SciTech Connect

    Tang, Zhe; Liu, Yunqi; Li, Guangci; Hu, Xiaofu; Liu, Chenguang

    2012-11-15

    Highlights: ► The γ-AlOOH hollow spheres were synthesized via an ionic liquid-assisted hydrothermal treatment. ► Ionic liquid plays an important role in the morphology of the product. ► Ionic liquid can be easily removed from the product and reused in next experiment. ► A “aggregation–solution–recrystallization” formation mechanism may occur in the system. -- Abstract: Hierarchically organized γ-AlOOH hollow spheres with nanoflake-like porous surface texture have been successfully synthesized via an ionic liquid-assisted hydrothermal synthesis method in citric acid monohydrate (CAMs). It was found that ionic liquid [bmim]{sup +}Cl{sup −} played an important role in the morphology of the product due to its strong interactions with reaction particles. The samples were characterized by X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscope (SEM) and Transmission Electron Microscopy (TEM). The results show that the product has narrow particle size distribution (500–900 nm particle diameter range), high specific surface area (240.5 m{sup 2}/g) and large pore volume (0.61 cm{sup 3}/g). The corresponding γ-Al{sub 2}O{sub 3} hollow spheres can be obtained by calcining it at 550 °C for 3 h. The proposed formation mechanism and other influencing factors of the γ-AlOOH hollow sphere material, such as reaction temperature, reaction duration, CAMs and urea, have also been investigated.

  1. Self-organization of jets in electrospinning from free liquid surface: A generalized approach

    NASA Astrophysics Data System (ADS)

    Lukas, David; Sarkar, Arindam; Pokorny, Pavel

    2008-04-01

    Electrospinning has enabled creation of excellent materials for a great number of applications. Previously, it was based on less productive capillary spinners. The present study is based on recent efforts to elevate electrospinning technology to an industrial level by simultaneously provoking innumerable polymeric jets from a sufficiently large liquid surface to increase productivity. Particularly, it deals with electrospinning from free surface of conductive liquids and validates a formulated hypothesis that explains self-organization of jets on one-dimensional free liquid surfaces in terms of electrohydrodynamic instability of surface waves. Here, it is shown how the hypothesis, based on a profound analysis of a dispersion law, explains that above a certain critical value of applied electric field intensity/field strength the system starts to be self-organized in mesocopic scale due to the mechanism of the "fastest forming instability." The mechanism plays a key role in selecting a particular wave with a characteristic wavelength whose amplitude boundlessly grows faster than the others. The fastest growing stationary wave, according to the hypothesis, marks the onset of electrospinning from a free liquid surface with its jets originating from the wave crests. Singularity of this approach lies in predicting critical values of the phenomenon, viz., critical field strength and corresponding critical interjet distance. The critical field strength, will, thereafter, be used in defining a unique dimensionless electrospinning number. It will, subsequently, be shown how the critical interjet distance, i.e., the maximal distance between the neighboring jets, simply depends on the capillary length. The capillary length represents a latent characteristic spatial scale of the system. The theory also predicts interjet distance for field strengths above the critical value. The said prediction is universally applicable for all conductive liquids if it is expressed in terms of

  2. 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.

  3. A facile route for creating "reverse" vesicles: insights into "reverse" self-assembly in organic liquids.

    PubMed

    Tung, Shih-Huang; Lee, Hee-Young; Raghavan, Srinivasa R

    2008-07-01

    Reverse vesicles are spherical containers in organic liquids (oils) consisting of an oily core surrounded by a reverse bilayer. They are the organic counterparts to vesicles in aqueous solution and could potentially find analogous uses in encapsulation and controlled release. However, few examples of robust reverse vesicles have been reported, and general guidelines for their formation do not exist. We present a new route for forming stable unilamellar reverse vesicles in nonpolar organic liquids, such as cyclohexane and n-hexane. The recipe involves mixing short- and long-chain lipids (lecithins) with a trace of a salt such as sodium chloride. The ratio of short- to long-chain lecithin controls the type and size of self-assembled structure. As this ratio is increased, a spontaneous transition from reverse micelles to reverse vesicles occurs. Small-angle neutron scattering (SANS) and transmission electron microscopy (TEM) confirm the presence of unilamellar vesicles in the corresponding solutions. Average vesicle diameters can be tuned from 60 to 250 nm depending on the sample composition.

  4. Liquid- and Ice-Phase Kinetics of Singlet Molecular Oxygen with Organic Pollutants

    NASA Astrophysics Data System (ADS)

    Bower, J. P.; Anastasio, C.

    2012-12-01

    Singlet molecular oxygen (1O2*), a reactive state of dissolved oxygen, is formed from a sensitizer chromophore that absorbs light and transfers energy to ground-state O2. The chemistry of 1O2* has been studied predominantly in surface waters and aqueous atmospheric drops, where 1O2* can be an important sink for electron-rich pollutants. In our recent work we have shown that 1O2* concentrations can be enhanced by several orders of magnitude on ice compared to in identical, but unfrozen, aqueous solutions. The goal of this work is to assess the potential importance of 1O2* to the decay of organic pollutants on ice in order to better understand pollutant cycling in the cryosphere. Using 549 nm radiation we illuminated liquid and bulk ice samples containing a 1O2* sensitizer (Rose Bengal), salt (NaCl), and an organic pollutant at a controlled temperature. Organic species were chosen to represent several chemical classes, including furans (furfuryl alcohol), phenols (bisphenol A), and amino acids (tryptophan). During illumination the decay of the pollutant was measured to determine the rate constant for loss by reaction with 1O2*. In all cases we observe enhanced loss of pollutants on ice relative to liquid samples. We will discuss how the magnitude of the ice-phase enhancement depends on the different pollutant classes, their aqueous solubility, and freezing point depression.

  5. Organics Produced by Irradiation of Frozen and Liquid HCN Solutions: Implications for Chemical Evolution Studies

    NASA Astrophysics Data System (ADS)

    Colín-García, M.; Negrón-Mendoza, A.; Ramos-Bernal, S.

    2009-04-01

    Hydrogen cyanide (HCN), an important precursor of organic compounds, is widely present in extraterrestrial environments. HCN is also readily synthesized in prebiotic simulation experiments. To gain insight into the radiation chemistry of one of the most important and highly versatile constituents of cometary ices, we examined the behavior of over-irradiated frozen and liquid HCN solutions under ionizing radiation. The samples were exposed to gamma radiation at a dose range from 0 up to 419 kGy. Ultraviolet spectroscopy and gas chromatography were used to follow the process. The analyses confirmed that gamma-ray irradiation of liquid HCN solutions generates several organic products. Many of them are essential to life; we verified the presence of carboxylic acids (some of them members of the Krebs cycle) as well as free amino acids and urea. These are the first studies to reveal the presence of these compounds in experiments performed at low temperatures and bulk irradiation. Organic material was produced even at low temperatures and low radiation doses. This work strongly supports the presumption that, as a parent molecule, HCN played a central essential role in the process of chemical evolution on early Earth, comets, and other extraterrestrial environments.

  6. Scintillation counters in modern high-energy physics experiments (Review)

    NASA Astrophysics Data System (ADS)

    Kharzheev, Yu. N.

    2015-07-01

    Scintillation counters (SCs) based on organic plastic scintillators (OPSs) are widely used in modern high-energy physics (HEP) experiments. A comprehensive review is given to technologies for production of OPS strips and tiles (extrusion, injection molding, etc.), optical and physical characteristics of OPSs, and methods of light collection based on the use of wavelength-shifting (WLS) fibers coupled to multipixel vacuum and silicon PMs. Examples are given of the use of SCs in modern experiments involved in the search for quarks and new particles, including the Higgs boson (D0, CDF, ATLAS, CMS), new states of matter (ALICE), CP violation (LHCb, KLOE), neutrino oscillations (MINOS, OPERA), and cosmic particles in a wide mass and energy interval (AMS-02). Scintillation counters hold great promise for future HEP experiments (at the ILC, NICA, FAIR) due to properties of a high segmentation, WLS fiber light collection, and multipixel silicon PMT readout.

  7. Analysis of organic solvents and liquid mixtures using a fiber-tip evaporation sensor

    NASA Astrophysics Data System (ADS)

    Preter, Eyal; Donlagic, Denis; Artel, Vlada; Katims, Rachel A.; Sukenik, Chaim N.; Zadok, Avi

    2014-05-01

    The instantaneous size and rate of evaporation of pendant liquid droplets placed on the cleaved facet of a standard fiber are reconstructed based on reflected optical power. Using the evaporation dynamics, the relative contents of ethanol in ethanol-water binary mixtures are assessed with 1% precision and different blends of methanol in gasoline are properly recognized. The latter application, in particular, is significant for the use of alternative fuels in the automotive sector. Also, ten organic solvents are identified based on their evaporation from a fiber facet coated with a hydrophobic, selfassembled monolayer.

  8. 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.

  9. 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.

  10. Scintillation at two optical frequencies.

    PubMed

    Hubbard, W B; Reitsema, H J

    1981-09-15

    Stellar scintillation data were obtained on a single night at a variety of zenith distances and azimuths, using a photon-counting photometer recording at 100 Hz simultaneously at wavelengths of 0.475 microm and 0.870 microm. Orientable apertures of 42-cm diam separated by 1 m were used to establish the average upper atmosphere wind direction and velocity. Dispersion in the earth's atmosphere separate the average optical paths at the two wavelengths, permitting a reconstruction of the spatial cross-correlation function for scintillations, independent of assumptions about differential fluid motions. Although there is clear evidence of a complicated velocity field, scintillation power was predominantly produced by levels at pressures of 130 +/- 30 mbar. The data are not grossly inconsistent with layers of isotropic Kolmogorov turbulence, but there is some evidence for deviation from the Kolmogorov spectral index and/or anisotropy.

  11. Fracture-resistant lanthanide scintillators

    DOEpatents

    Doty, F. Patrick

    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.

  12. 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.

  13. 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.

  14. Aqueous liquid feed organic fuel cell using solid polymer electrolyte membrane

    NASA Technical Reports Server (NTRS)

    Surampudi, Subbarao (Inventor); Narayanan, Sekharipuram R. (Inventor); Vamos, Eugene (Inventor); Frank, Harvey A. (Inventor); Halpert, Gerald (Inventor); Olah, George A. (Inventor); Prakash, G. K. Surya (Inventor)

    1997-01-01

    A liquid organic fuel cell is provided which employs a solid electrolyte membrane. An organic fuel, such as a methanol/water mixture, is circulated past an anode of a cell while oxygen or air is circulated past a cathode of the cell. The cell solid electrolyte membrane is preferably fabricated from Nafion.TM.. Additionally, a method for improving the performance of carbon electrode structures for use in organic fuel cells is provided wherein a high surface-area carbon particle/Teflon.TM.-binder structure is immersed within a Nafion.TM./methanol bath to impregnate the electrode with Nafion.TM.. A method for fabricating an anode for use in a organic fuel cell is described wherein metal alloys are deposited onto the electrode in an electro-deposition solution containing perfluorooctanesulfonic acid. A fuel additive containing perfluorooctanesulfonic acid for use with fuel cells employing a sulfuric acid electrolyte is also disclosed. New organic fuels, namely, trimethoxymethane, dimethoxymethane, and trioxane are also described for use with either conventional or improved fuel cells.

  15. Selective Identification of Organic Iodine Compounds Using Liquid Chromatography-High Resolution Mass Spectrometry.

    PubMed

    Yang, Yijun; Peng, Yue'e; Chang, Qing; Dan, Conghui; Guo, Wei; Wang, Yanxin

    2016-01-19

    A method to selectively and sensitively detect organic iodine compounds and identify their structures has been developed using liquid chromatography-high resolution mass spectrometry (LC-HRMS). Using extracted ion chromatograms of product ions (iodine ion) collected on a rapid scanning quadrupole orbitrap mass spectrometer, the retention times of the unknown organic iodine compounds were determined, and the structural information were acquired according to the MS/MS experiments and the matching with reference standards. We have demonstrated the application of this method by identifying unknown organic iodine compounds in seaweed. A total of 28 possible organic iodine peaks were discovered, among them, the accurate mass and element composition of the corresponding precursor ions were identified for 12 peaks, and molecular structures were confirmed for 4 peaks, which were 3-iodo-L-tyrosine, 3,5-diiodo-L-tyrosine, 4-iodophenol, and 2-iodobenzoic acid. This method is expected to lead to the future discovery of new organic iodine compounds via LC-HRMS in different environmental samples, which is crucial for understanding the iodine biogeochemical cycling.

  16. Three-dimensional printing of scintillating materials.

    PubMed

    Mishnayot, Y; Layani, M; Cooperstein, I; Magdassi, S; Ron, G

    2014-08-01

    We demonstrate, for the first time, the applicability of three-dimensional printing techniques to the manufacture of scintillation detectors. We report on the development of a formulation, usable in stereolithographic printing, that exhibits scintillation efficiency on the order of 30% of that of commercial polystyrene based scintillators. We discuss the applicability of these techniques and propose future enhancements that will allow tailoring the printed scintillation detectors to various applications.

  17. Panoscopic organization of anisotropic colloidal structures from photofunctional inorganic nanosheet liquid crystals.

    PubMed

    Nakato, Teruyuki; Nono, Yoshihiro; Mouri, Emiko; Nakata, Munetaka

    2014-01-21

    Colloidal liquid crystals of inorganic nanosheets with thickness of around 1 nm and lateral dimensions of several micrometers prepared by exfoliation of a layered niobate are converted to hierarchically organized arrays whose structures are controlled from the nano to macroscopic length scale through the growth of liquid crystalline domains called tactoids as the secondary building blocks followed by controlled application of external fields. Growth of the tactoids is attained by incubation of the liquid crystals at room temperature. The tactoids are then assembled into higher-order structures with characteristic lengths of sub-mm to mm under the simultaneous application of an ac electric field and gravity, whose directions determine the final textural motif of the arrays. Whereas a net-like texture is observed when applying the electric and gravitational forces in the same direction, a striped texture where the nanosheets are unidirectionally aligned is observed when the electric field is applied in the direction perpendicular to gravity. The use of well-grown tactoids is key to the macroscopic structural control. Since the niobate nanosheets have wide band-gap semiconducting nature, the nanosheet stripe arrays exhibit photocatalysis that reflected the alignment of the nanosheets with respect to the polarized direction of impinging light.

  18. Feasibility study of the applicability of the activated sludge process to treatment of radioactive organic liquid waste

    SciTech Connect

    Koyama, Akio; Nishimaki, Kenzo

    1997-12-31

    The authors used an activated sludge process to treat radioactive organic liquid waste. Organic liquid waste is difficult to treat by conventional radioactive liquid treatment processes, but in order to reduce long-term irradiation of the public the removal of radionuclides from such waste is preferable to dilution. Activated sludge processes are widely used for the biological treatment of sewage and are considered appropriate means for treating radioactive organic liquid waste. In this process, the fate of radionuclides eluted by treated water or immobilized by activated sludge, is extremely important for public safety and for the treatment of radioactive organic liquid waste. The authors performed uptake and desorption behavior experiments on the three short half-life radionuclides {sup 134}Cs, {sup 57}Co and {sup 85}Sr, and used three nutritive types of artificial sewage as the feed solution. On the basis of the results, they discuss the uptake-desorption behavior of these radionuclides in an activated sludge process. The authors conclude that treatment of radioactive organic liquid waste by an activated sludge process is possible, but improvements must be made in the process if it is to be more effective.

  19. 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

  20. MCNPX--PoliMi Variance Reduction Techniques for Simulating Neutron Scintillation Detector Response

    NASA Astrophysics Data System (ADS)

    Prasad, Shikha

    Scintillation detectors have emerged as a viable He-3 replacement technology in the field of nuclear nonproliferation and safeguards. The scintillation light produced in the detectors is dependent on the energy deposited and the nucleus with which the interaction occurs. For neutrons interacting with hydrogen in organic liquid scintillation detectors, the energy-to-light conversion process is nonlinear. MCNPX-PoliMi is a Monte Carlo Code that has been used for simulating this detailed scintillation physics; however, until now, simulations have only been done in analog mode. Analog Monte Carlo simulations can take long times to run, especially in the presence of shielding and large source-detector distances, as in the case of typical nonproliferation problems. In this thesis, two nonanalog approaches to speed up MCNPX-PoliMi simulations of neutron scintillation detector response have been studied. In the first approach, a response matrix method (RMM) is used to efficiently calculate neutron pulse height distributions (PHDs). This method combines the neutron current incident on the detector face with an MCNPX-PoliMi-calculated response matrix to generate PHDs. The PHD calculations and their associated uncertainty are compared for a polyethylene-shielded and lead-shielded Cf-252 source for three different techniques: fully analog MCNPX-PoliMi, the RMM, and the RMM with source biasing. The RMM with source biasing reduces computation time or increases the figure-of-merit on an average by a factor of 600 for polyethylene and 300 for lead shielding (when compared to the fully analog calculation). The simulated neutron PHDs show good agreement with the laboratory measurements, thereby validating the RMM. In the second approach, MCNPX-PoliMi simulations are performed with the aid of variance reduction techniques. This is done by separating the analog and nonanalog components of the simulations. Inside the detector region, where scintillation light is produced, no variance